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Postictal language function
Epilepsy & Behavior 19 (2010) 140–145
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Epilepsy & Behavior j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / ye b e h
Review
Postictal language function Michael Privitera a,b,⁎, Kwang Ki Kim a,c a b c
Department of Neurology, University of Cincinnati, Cincinnati, OH, USA Cincinnati Epilepsy Center, University of Cincinnati Neuroscience Institute, Cincinnati, OH, USA Department of Neurology, Dongguk University International Hospital, Gooyang-shi, Kyeonggi-do, Korea
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Article history: Received 17 June 2010 Accepted 17 June 2010 Available online 8 August 2010 Keywords: Postictal Language Seizure Temporal lobe epilepsy
a b s t r a c t Language function in the postictal state can be successfully assessed and provides valuable information on seizure localization and spread. Several studies have shown that postictal paraphasic errors and ictal speech have value for seizure localization. The Cincinnati method is a simple, repeatable test that involves presenting a single test sentence on a card and asking the patient to read the sentence repeatedly until it is read correctly. It increases the yield of detecting paraphasic errors and ictal speech, and provides a quantitative measure of language recovery known as the postictal language delay, defined as the time from the end of the EEG ictal discharge until the test sentence is read correctly. This language testing method has been used for all patients admitted to the epilepsy monitoring unit at the Cincinnati Epilepsy Center for more than 20 years and has been shown to: (1) lateralize temporal lobe complex partial seizures; (2) identify when temporal lobe complex partial seizures spread to the dominant hemisphere; (3) identify patients with atypical language lateralization; (4) distinguish between temporal and frontal complex partial seizures; and (5) provide some insight into speech prosody changes in nondominant temporal lobe complex partial seizures. The method has some limitations because it requires vigilance of the patient and direct interaction by the technologist, and may be incomplete as a result of patient agitation, but has been successfully completed in more than 80% of patients admitted to the epilepsy monitoring unit. This highly cost-effective test provides important information on seizure localization and spread; is easily taught to technologists, nurses, and family members; and should be added to testing procedures in all epilepsy monitoring units. © 2010 Elsevier Inc. All rights reserved.
1. Introduction One-third of all people with epilepsy have incomplete seizure control with antiepileptic drugs [1]. Surgical resection can be an effective treatment modality to cure many patients, but its success demands accurate localization of the onset and spread patterns of partial onset seizures. A multimodal approach including electroencephalography (ictal and interictal), brain magnetic resonance imaging (MRI, both structural and functional), single-photon emission computed tomography (SPECT, both ictal and interictal), and positron emission tomography (PET) is currently used to localize the seizure onset zone and seizure spread. No single test localizes seizure onset regions and predicts postsurgical outcome; therefore, a combination of tests is used. It is especially helpful to have tests that localize seizure onset in patients with temporal lobe complex partial seizures (TLCPSs) because individuals with these seizures have
⁎ Corresponding author. Department of Neurology, University of Cincinnati Academic Health Center, 260 Stetson Street; Suite 2300, Cincinnati, OH 45267-0525, USA. E-mail address: [email protected] (M. Privitera). 1525-5050/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.yebeh.2010.06.028
the best outcome after surgery compared with those with other seizure types. A variety of ictal behaviors have been analyzed to complement these structural and functional tests to better localize seizure onset and spread. However, interpretation of all studies is confounded by nonlocalizing findings and bilateral abnormalities; in addition, studies that rely on ictal findings may be confounded by seizure spread patterns. Other ictal behaviors of localizing value are discussed elsewhere in this Special Issue, and this review focuses on disturbances of language. Ictal and postictal disturbances of language have been extensively studied in complex partial seizures and provide an accurate but seldom used method to localize seizures. Hughlings Jackson (1898) first noted language disturbances in dominant hemisphere seizures [2], and Bingley [3], Serafetinides and Falconer [4], and King and coworkers [5] correlated ictal or postictal dysphasia and dominant hemisphere seizure foci. After the introduction of simultaneous video/EEG recording, identification of ictal and postictal language disturbances became more accurate and now provides stronger evidence for seizure localization and language dominance. McKeever et al. measured expressive dysphasia or speech arrest and found abnormalities in all seven patients with left hemisphere seizures [6].
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Koerner et al. measured “impaired speech” and found that 82% of patients with left hemispheric seizures had impaired speech [7], and 83% of patients with formed ictal speech had seizures originating from the nondominant hemisphere. Gabr et al. reported that 75% of individuals with left hemispheric seizures had impaired speech and 83% of patients with formed ictal speech had non-dominant hemisphere seizures [8]. The Cincinnati Epilepsy Center at the University of Cincinnati Neuroscience Institute has employed a standard testing approach for more than 20 years in the inpatient epilepsy monitoring unit for assessment of ictal and postictal lanugage. We have discovered consistent and localizing patterns of ictal and postictal language disturbance, and this review summarizes our findings. We hope that this simple technique of methodically testing people with seizures during the ictal and postictal states will be incorporated into epilepsy monitoring units worldwide. 2. The Cincinnati method for ictal and postictal language testing Since 1988 all patients admitted to the epilepsy monitoring unit at University Hospital in Cincinnati have been assessed in a standard way to test language. As soon as a seizure is detected, the technologist or nurse comes into the room, presents the printed sign with a test sentence, and instructs the patient to read aloud until the sentence is read clearly and correctly. The test sentence is from the Boston Diagnostic Aphasia Test: “They heard him speak on the radio last night.” All patients are assessed for ability to read the test sentence between seizures during the initial EEG hookup. For the testing, every room has one or more 8.5 × 11-in. cards with 1-in. block letters; technologists and physicians carry smaller pocket versions. A single sentence is used because it is repeatable, and errors and speech disturbances can be more readily detected despite room noise or suboptimal audio recordings. Technologists have been trained to flash the test sign at the camera when the sentence is read correctly and state out loud when a patient makes a paraphasic error; these techniques further improve results in suboptimal audio situations. On many occasions, families can be instructed to effectively administer the testing. It appears that a patient memorizing the sentence has had no effect on results. The technique was initiated in 1988 with the goal of increasing detection of postictal paraphasic errors, because before that time, technologists and nurses often entered the room and had limited and inconsistent verbal interaction with the patient. Subsequently, we found several parameters with localizing value that are described below. Our current practice is to analyze the seizure recording for three parameters: (1) presence of paraphasic errors (ictal or postictal); (2)
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presence of formed ictal speech; and (3) postictal language delay (PILD). We calculate PILD as the time from the end of EEG ictal discharge to the time the patient reads the test sentence correctly. 3. Postictal language delay accurately lateralizes temporal lobe complex partial seizures An initial analysis of postictal language testing results showed remarkably accurate lateralization of TLCPSs [9]. Privitera et al. analyzed 105 seizures in 26 patients with seizure localization determined by postsurgical success. Postictal paraphasias were found in 46 of 62 seizures (11/14 patients). In all 62 left temporal seizures the language delay (PILD) was longer than 60 seconds (range: 68–1276 seconds). For 42 of 43 seizures from the right temporal lobe, the language delay was less than 60 seconds (range: 0–106 seconds) (Fig. 1). In this initial sample, using a cutoff of 60 seconds for PILD, 104 of 105 seizures were accurately lateralized. Interestingly, pure left mesial temporal simple partial seizures recorded with depth electrodes did not reveal impairment of language. These findings compared favorably with those of lateralization using other noninvasive methods like PET, MRI, and scalp EEG. From this analysis, we concluded that measuring PILD is the most accurate and reproducible method to test language in the ictal/ postictal period for patients with TLCPSs. 4. Atypical patterns of postictal language delay can identify patients with atypical language lateralization Postictal language patterns may be altered if patients have atypical localization of language function. Privitera et al. analyzed 64 patients with TLCPSs who underwent epilepsy surgery after an intracarotid amobarbital test (IAT) or direct electrocortical mapping [9]. Of 11 patients with IAT-proven right hemispheric or bilateral language dominance, 10 had “discordant” postictal language testing results. Postictal language patterns were classified as concordant or discordant with eventual epileptogenic focus localization using a PILD cutoff of 60 seconds derived from our initial study showing the high accuracy of this method [9]. Seizures were classified as concordant in patients with right TLCPSs if language delays b60 seconds occurred, whereas those with concordant left TLCPSs had language delays N60 seconds. Patients with discordant right TLCPSs had language delays N60 seconds, and those with discordant left TLCPSs had language delays b60 seconds. Patients with multiple seizures were classified as having a discordant postictal language pattern if any seizure showed a discordant language delay pattern. Discordant postictal language patterns were noted in 10 of 11 patients with IATdocumented nonleft language dominance and in 15 of 53 with left
Fig. 1. Graph demonstrating duration of postictal language delay (PILD) in right and left temporal lobe complex partial seizures. In this initial series, all but one seizure in one patient was correctly lateralized using a 60-second cutoff. Of 105 seizures, 104 were accurately lateralized with this cutoff.
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dominance (P = 0.006; sensitivity 90.9%, specificity 71.7%). In the 53 patients with left language dominance, postictal language testing correctly lateralized seizure onset in 38 patients (72%), was nonlateralizing in 10 (19%), and was falsely lateralizing in 5 (9%). 5. Postictal language delay patterns indicate onset or spread of seizures to the language-dominant temporal lobe Ficker et al. studied the effect of seizure spread from one temporal lobe to the other on postictal language patterns [10]. Fifteen of 40 patients who underwent prolonged video/EEG monitoring with intracranial depth electrodes from 1989 to 1997 had 69 TLCPSs that met the study criteria (29 nondominant and 40 dominant temporal onset). Typically, patients had six-contact depth electrodes inserted from a lateral approach under stereotactic guidance into bilateral amygdalar, hippocampal, and orbitofrontal regions. One patient had independent onset of seizures from both dominant and nondominant hemispheres. In two patients, some of their seizures propagated to the contralateral temporal lobe and some did not. All seizures had onset in the mesial temporal lobe. Fourteen of 15 patients had bilateral independent interictal spikes. Only two patients had hippocampal atrophy on MRI; the remainder of the patients had normal imaging studies. Seizures that began in the nondominant temporal lobe and propagated to the contralateral dominant temporal lobe were associated with a significantly longer PILD than seizures that did not propagate and were more likely to be associated with paraphasic errors (Table 1). Seven of 16 seizures that propagated from the nondominant temporal lobe to the dominant temporal lobe spread to the mesial temporal lobe structures only. The remaining nine seizures spread to both neocortical and mesial temporal lobe structures. All of the seizures that propagated from the dominant temporal lobe to the nondominant temporal lobe spread to the mesial temporal lobe structures only. PILD and paraphasic errors did not significantly differ between propagated and nonpropagated dominant-onset temporal lobe seizures. For seizures that originated in the nondominant temporal lobe and propagated to the dominant temporal lobe, a shorter propagation time was associated with a longer PILD (P b 0.01); however, the duration of electrographic seizure activity in the dominant temporal lobe (after propagation) did not influence PILD. There was no difference in postictal language behavior between propagated and nonpropagated dominant-onset temporal lobe seizures. These results indicate that ictal involvement of the dominant temporal lobe is the most important driver of postictal language behavior in TLCPSs. 6. Postictal language patterns can distinguish frontal from temporal lobe seizures and identify frontal-to-temporal spread patterns Goldberg-Stern et al. reported on postictal language patterns in 24 patients with 118 frontal lobe CPSs with or without spread to the
Table 1 Summary of postictal language data in seizures that spread from one temporal lobe to the other. Parameter
Nondominant TLCPSs (n=29) Dominant TLCPSs (n=40) Propagated (n = 16)
Mean (SD) postictal 443.0 language delay, s (389.8) Paraphasic errors 8/16
Not propagated (n = 13) 18.5 (19.6)a 0/13b
ipsilateral temporal lobe [11]. The diagnosis of frontal lobe CPSs was based on the presence of one of the following criteria: (1) the presence of frontal seizures as monitored by video/EEG in patients who underwent resection of a frontal lobe epileptogenic focus that resulted in a ≥90% decrease in seizure frequency during at least 2 years of followup (n = 2); (2) the presence of frontal seizures as monitored by video/ EEG in patients with frontal lobe anatomic lesions and medically intractable seizures who did not undergo surgical resection (n = 5); (3) the presence of frontal seizures as monitored with either subdural or depth electrodes in patients who did not undergo surgical resection (n = 17). All were right-handed, and language dominance was assessed by either IAT or direct cortical stimulation. Temporal spread was diagnosed if seizures arose in the frontal lobe and later spread to the temporal lobe during invasive EEG monitoring. If patients had only scalp EEG monitoring, temporal lobe spread was identified if frontal lobe seizure onset was recorded and followed by a late (N30 seconds after seizure onset), rhythmic, and N5-Hz temporal lobe ictal discharge. The seizures were categorized into four groups: (1) dominant frontal CPSs; (2) nondominant frontal CPSs; (3) dominant frontal onset CPSs with ipsilateral temporal spread; (4) nondominant frontal onset CPSs with ipsilateral temporal spread. Seizures originating from the dominant frontal lobe and spreading to the ipsilateral temporal lobe were associated with the longest PILD (median = 546.8 seconds) and were longer than CPSs confined to the dominant frontal lobe (median PILD = 30.2 seconds) (P = 0.0001). Prolonged PILD (defined as PILD N60 seconds) occurred in only 7% of CPSs confined to the dominant frontal lobe compared with 91% of CPSs that started as frontal and spread to the dominant temporal lobe (P b 0.0001). Seizures confined to the nondominant frontal lobe were associated with the shortest PILD (mean = 17.3 seconds). PILD was longer for seizures confined to the nondominant frontal lobe than for those originating in the nondominant frontal lobe and spreading to the ipsilateral temporal lobe (means = 30.2 and 23.6 seconds, respectively), but the difference did not reach statistical significance. Postictal language testing provides important information on frontal CPS localization and spread. To summarize the results in frontal lobe seizures, the postictal language findings are related primarily to seizure spread patterns. Prolonged postictal language dysfunction occurs when seizures originate or spread to the dominant temporal lobe and rarely with other cortical areas. Language patterns following dominant frontal-totemporal seizure spread appear indistinguishable from seizures that arise in the dominant temporal lobe. Dominant frontal lobe seizures differ greatly from nondominant temporal lobe seizures, rarely causing reading delay or paraphasias and sometimes showing ictal speech. Surprisingly, ictal reading without errors occurred in an equal number of seizures that were confined to the dominant and nondominant frontal lobes. The most remarkable finding was that the proximity of seizures to expressive language areas in the frontal lobe had no measurable effect on language measures. PILD changes
Table 2 Comparison of postictal language measures in dominant and nondominant seizures confined to frontal lobes compared with ipsilateral spread.
Propagated Not propagated (n = 19) (n = 21) 298.4 (459.8) 9/19
448.8 (425.6) 12/21
a P b 0.0001, GENMOD procedure, for propagated nondominant temporal lobe seizures. b P b 0.003, Fisher's exact test, for presence of paraphasic errors in propagated nondominant temporal lobe seizures.
Number of seizures Mean PILD Paraphasias PILD N 60 s Ictal reading a
Dominant
Nondominant
Dominant
Nondominant
FLa
FL
FL → TL
FL → TL
55 30.2 5% 7% 18%
24 17.3 0 0 16%
22 546.8 27% 90% 0
17 23.6 0 0 5%
FL, frontal lobe; TL, temporal lobe; PILD, postictal language delay.
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appear to be related to disruption of temporal lobe language networks and not a function of proximity of seizures to primary language areas (Table 2). 7. Speech prosody changes during nondominant temporal lobe complex partial seizures Patients with CPSs from the nondominant temporal lobe often read the test sentence during the ictal discharge. Paraphasic errors during the ictal discharge can occur with seizures from either temporal lobe; however a small number of patients with nondominant TLCPSs show alterations in speech prosody. Although these changes are usually obvious when listening to the audio during the seizure, speech prosody changes are difficult to quantify using accepted acoustical methods because of suboptimal recordings due to room noise, imperfect microphone localization, and other factors that are difficult to control in an epilepsy monitoring unit. Karolchyk et al. [12] reported on five subjects with nondominant TLCPSs who read the test sentence during the ictal discharge and had adequate acoustical quality for analysis. Acoustical analysis measured pitch, fundamental frequencies, and excursions. Three of the five subjects showed higher pitch and decreased excursions (flattened intonation). Boyce et al. [13] studied a single additional patient using more detailed acoustic analyses. They compared the patient's ictal speech while reading the test sentence with his own interictal (normal state) speech and also with 10 normal speakers’ fast and slow speech. The patient had right TLCPSs documented by video/EEG monitoring and subsequently had N90% seizure reduction after right anterior temporal lobectomy. IAT showed left hemisphere language dominance. Total duration (including pauses) was used as an index of speech rate. To measure “scanning” speech, the SI index suggested by Hertrich and Ackermann [14] was used. Vocal instabilities were measured visually from 1024-point narrow-band spectrograms as the number of short-duration fundamental frequency modulations over time. Four separate seizures were analyzed. Ictal speech showed a slower rate with a higher SI index, significantly more vocal instabilities, and isosynchrony. These findings had some similarities to ataxic speech. Overall, the findings from these two small studies indicate that patients with nondominant TLCPSs who are able to read during the ictal discharge show fairly consistent speech prosody changes with higher pitch, slower speed, somewhat flattened intonation, and a scanning quality. The rarity of these findings and the difficulty in analysis because of suboptimal recordings make the findings challenging to use for seizure localization. Nevertheless, without the standard postictal language testing method, these analyses would not have been possible. 8. Report of a “blurry sign” is highly associated with psychogenic nonepileptic seizures Lannon studied postictal language testing in a series of patients with psychogenic nonepileptic seizures identified with video/EEG monitoring who were tested using the Cincinnati method described above [15]. The test sentence is printed in large 1-in. block letters that are easy to read, so even patients who are not wearing usual corrective lenses can easily identify the words. Tapes of 31 consecutive patients diagnosed with only psychogenic events were analyzed and compared with those of 31 patients with CPSs (18 dominant/ 8 nondominant temporal lobe, 4 frontal, 1 occipital). In both groups the first event was used. Seventeen patients with psychogenic seizures responded either “I can't see it” or “It's blurry”; 14 read correctly. Twelve patients with CPSs read correctly (8 dominant, 4 frontal); one (occipital) said “I can't read it”; 18 (dominant) had a language delay N60 seconds, 8 with
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paraphasic errors. No patient with CPSs said “I can't see it” or “It's blurry”; patients with CPSs either read the sign with or without paraphasic errors or did not read at all. In the absence of seizures causing a postictal visual disturbance (typically occipital), the report that the sign is blurry in the postictal period is highly associated with psychogenic nonepileptic seizures. In this series, more than half the patients with psychogenic nonepileptic seizures reported that the sign was blurry. 9. Postictal language delay, postictal paraphasic errors, and interictal paraphasic errors have similar and additive diagnostic accuracy in lateralizing temporal lobe complex partial seizures Ramirez et al. studied 60 subjects who underwent inpatient video/ EEG monitoring and had surgically confirmed TLE to assess the relative performance of various language measures in seizure localization [16]. They determined the presence and number of postictal paraphasic errors and PILD times (in seconds) for 212 seizures and interictal paraphasic errors on the Boston Naming Test (BNT). Each technique's diagnostic usefulness was evaluated via logistic regression and receiver operating characteristic curve analysis. PILD, postictal paraphasic error production, and interictal paraphasic error production were equally effective and accurate in lateralizing TLCPS onset. Patients with dominant TLCPSs had a longer PILD and committed more postictal and interictal paraphasic errors than those with nondominant TLCPSs. Sensitivity and specificity values were as described in Table 3. No single predictor was significantly better, but a combination model yielded enough incremental utility to collectively outperform each separate predictor model. These more recent findings show that the Cincinnati method of language testing has high accuracy, but that accuracy can be improved when combined with interictal tests of language function (Table 3). 10. Age and presence of a structural lesion have little effect on postictal language delay Several case reports had suggested that older age or the presence of a structural lesion substantially increases language recovery time after seizures [17–19]. Goldberg-Stern et al. assessed the influence of age and a brain structural lesion on postictal language measures using the Cincinnati method for language testing [20]. They analyzed 173 seizures of 47 patients with TLCPSs (28 dominant, 19 nondominant). Age did not affect PILD regardless of the lateralization of the seizures. The presence of a structural lesion significantly prolonged PILD only in the patients with nondominant TLCPSs (P = 0.019). One limitation of the study was that the mean patient age was less than 40 years; although no obvious trend was seen in the results, different results may have been seen in a substantially older population. In addition, rare instances of very prolonged postictal language impairment may be seen in patients with dominant temporal lobe structural lesions. One of the authors (M.P.) has personal experience with two patients with dominant temporal lobe structural lesions, one a large stroke
Table 3 Comparison of diagnostic utilities for postictal language delay (PILD), postictal paraphasic errors (Post-PE), and interictal paraphasic errors (Inter-PE).
PILD Inter-PE Post-PE
Sensitivity
Specificity
Positive predictive value
Negative predictive value
84% 97% 94%
86% 86% 64%
87% 89% 75%
83% 96% 90%
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and the other a thrombosed arteriovenous malformation, both of whom experienced recurrent episodes of postictal aphasia with paraphasic errors lasting days to weeks after generalized tonic–clonic seizures. The EEG in these cases showed no evidence of aphasic status epilepticus. 11. Aphasic status epilepticus Postictal language delay must be differentiated from complex partial status epilepticus with aphasia. Aphasic status epilepticus may manifest with global, Broca, Wernicke, or mixed types of aphasia and include paraphasic errors [21–23]. PILD and paraphasic errors are defined as occurring after the EEG ictal discharge has ended. In the initial study of PILD, several patients were studied with both scalp and depth EEGs; the end of the EEG discharge was seen essentially simultaneously on scalp and depth EEG recordings [9]. Thus, scalp EEG in most cases appears to be sufficient to differentiate between aphasic status epilepticus and postictal language impairment. 12. Postictal “confusion” is most often a language disturbance and rarely interferes with adequate postictal language testing A frequent criticism of the postictal language testing method is that it will be confounded by postictal “confusion.” At the Cincinnati Epilepsy Center we have employed this testing method on several thousand patients since 1988 and found that “confusion” rarely impacts testing. Specifically for this review, we evaluated a sequential sample of 100 patients admitted to the epilepsy monitoring unit starting in January 2009 to determine how often adequate postictal language testing was performed. Excluded seizures were either psychogenic nonepileptic, tonic–clonic, simple partial, or electrographic. Ninety-one seizures (complex partial or absence) in 48 patients were reviewed. Adequate testing was performed in 79 (86.8%). Causes for inadequate testing were seizures that were missed by the observing technologist (n = 8), patient off camera (n = 1), isotope injection for ictal SPECT (n = 1), and confusion or agitation (n = 2). Thus, postictal agitation or confusion can occur in the epilepsy monitoring unit, but infrequently interferes with adequate postictal language testing. 13. Postictal visual field defects can occasionally be detected using the language test Infrequently patients with postictal hemianopsia are identified because they will read correctly only the words on the left or right half of the test sign. This has occurred solely with occipital seizures, and appears to be detectable only when there is a full hemianopsia and not merely a quadrantanopsia. 14. Limitations of postictal language testing The Cincinnati method for postictal language assessment is simple to apply and interpret, but there are limitations in its application. First, the patient must have adequate intelligence and visual function to be able to read the test sign at baseline. Second, adequate assessment of PILD generally requires testing to be initiated within 60 seconds of the end of the seizure. This requires vigilance by the technologist, nurse, or family member to rapidly identify a seizure and present the test sentence. However, if the test sign is presented after 60 seconds, the test is considered inadequate only if the patient reads the sentence on the first attempt without paraphasic errors. Third, language testing has not been adequately studied following tonic–clonic seizures primarily because it typically requires a minimum of 10–20 minutes for language function to return and it has not been feasible to have a technologist test for this duration, especially if the technologist is monitoring multiple patients at once.
Fourth, although “confusion” in the postictal state generally does not interfere with adequate testing, there are clearly situations where a patient has postictal agitation and the testing cannot be adequately performed. Fifth, no study of non-English speakers has been performed; however, at the Cincinnati Epilepsy Center we have translated the test sentence into several different languages and asked translators to review the recordings for accuracy and paraphasic errors. Finally, suboptimal audio recordings and room noise can interfere with detection of paraphasic errors and accurate assessment of the time of correct reading. We instruct technologists to state out loud when they hear a paraphasic error and to clearly identify when the patient reads the sentence correctly. 15. Summary Assessment of language function in the postictal state can be successfully performed and provides valuable information on seizure localization and spread. The Cincinnati method is a simple, repeatable test easily taught to technologists, nurses, and family members. It increases the yield of paraphasic errors and provides a quantitative measure of language recovery. This language testing method has been shown to lateralize TLCPSs, identify when TLCPSs spread to the dominant hemisphere, identify patients with atypical language lateralization, distinguish between temporal and frontal CPSs, and provide some insight into speech prosody changes in nondominant TLCPSs. This highly cost-effective test should be added to testing procedures in all epilepsy monitoring units.
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Epilepsy & Behavior j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / ye b e h
Review
Postictal language function Michael Privitera a,b,⁎, Kwang Ki Kim a,c a b c
Department of Neurology, University of Cincinnati, Cincinnati, OH, USA Cincinnati Epilepsy Center, University of Cincinnati Neuroscience Institute, Cincinnati, OH, USA Department of Neurology, Dongguk University International Hospital, Gooyang-shi, Kyeonggi-do, Korea
a r t i c l e
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Article history: Received 17 June 2010 Accepted 17 June 2010 Available online 8 August 2010 Keywords: Postictal Language Seizure Temporal lobe epilepsy
a b s t r a c t Language function in the postictal state can be successfully assessed and provides valuable information on seizure localization and spread. Several studies have shown that postictal paraphasic errors and ictal speech have value for seizure localization. The Cincinnati method is a simple, repeatable test that involves presenting a single test sentence on a card and asking the patient to read the sentence repeatedly until it is read correctly. It increases the yield of detecting paraphasic errors and ictal speech, and provides a quantitative measure of language recovery known as the postictal language delay, defined as the time from the end of the EEG ictal discharge until the test sentence is read correctly. This language testing method has been used for all patients admitted to the epilepsy monitoring unit at the Cincinnati Epilepsy Center for more than 20 years and has been shown to: (1) lateralize temporal lobe complex partial seizures; (2) identify when temporal lobe complex partial seizures spread to the dominant hemisphere; (3) identify patients with atypical language lateralization; (4) distinguish between temporal and frontal complex partial seizures; and (5) provide some insight into speech prosody changes in nondominant temporal lobe complex partial seizures. The method has some limitations because it requires vigilance of the patient and direct interaction by the technologist, and may be incomplete as a result of patient agitation, but has been successfully completed in more than 80% of patients admitted to the epilepsy monitoring unit. This highly cost-effective test provides important information on seizure localization and spread; is easily taught to technologists, nurses, and family members; and should be added to testing procedures in all epilepsy monitoring units. © 2010 Elsevier Inc. All rights reserved.
1. Introduction One-third of all people with epilepsy have incomplete seizure control with antiepileptic drugs [1]. Surgical resection can be an effective treatment modality to cure many patients, but its success demands accurate localization of the onset and spread patterns of partial onset seizures. A multimodal approach including electroencephalography (ictal and interictal), brain magnetic resonance imaging (MRI, both structural and functional), single-photon emission computed tomography (SPECT, both ictal and interictal), and positron emission tomography (PET) is currently used to localize the seizure onset zone and seizure spread. No single test localizes seizure onset regions and predicts postsurgical outcome; therefore, a combination of tests is used. It is especially helpful to have tests that localize seizure onset in patients with temporal lobe complex partial seizures (TLCPSs) because individuals with these seizures have
⁎ Corresponding author. Department of Neurology, University of Cincinnati Academic Health Center, 260 Stetson Street; Suite 2300, Cincinnati, OH 45267-0525, USA. E-mail address: [email protected] (M. Privitera). 1525-5050/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.yebeh.2010.06.028
the best outcome after surgery compared with those with other seizure types. A variety of ictal behaviors have been analyzed to complement these structural and functional tests to better localize seizure onset and spread. However, interpretation of all studies is confounded by nonlocalizing findings and bilateral abnormalities; in addition, studies that rely on ictal findings may be confounded by seizure spread patterns. Other ictal behaviors of localizing value are discussed elsewhere in this Special Issue, and this review focuses on disturbances of language. Ictal and postictal disturbances of language have been extensively studied in complex partial seizures and provide an accurate but seldom used method to localize seizures. Hughlings Jackson (1898) first noted language disturbances in dominant hemisphere seizures [2], and Bingley [3], Serafetinides and Falconer [4], and King and coworkers [5] correlated ictal or postictal dysphasia and dominant hemisphere seizure foci. After the introduction of simultaneous video/EEG recording, identification of ictal and postictal language disturbances became more accurate and now provides stronger evidence for seizure localization and language dominance. McKeever et al. measured expressive dysphasia or speech arrest and found abnormalities in all seven patients with left hemisphere seizures [6].
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Koerner et al. measured “impaired speech” and found that 82% of patients with left hemispheric seizures had impaired speech [7], and 83% of patients with formed ictal speech had seizures originating from the nondominant hemisphere. Gabr et al. reported that 75% of individuals with left hemispheric seizures had impaired speech and 83% of patients with formed ictal speech had non-dominant hemisphere seizures [8]. The Cincinnati Epilepsy Center at the University of Cincinnati Neuroscience Institute has employed a standard testing approach for more than 20 years in the inpatient epilepsy monitoring unit for assessment of ictal and postictal lanugage. We have discovered consistent and localizing patterns of ictal and postictal language disturbance, and this review summarizes our findings. We hope that this simple technique of methodically testing people with seizures during the ictal and postictal states will be incorporated into epilepsy monitoring units worldwide. 2. The Cincinnati method for ictal and postictal language testing Since 1988 all patients admitted to the epilepsy monitoring unit at University Hospital in Cincinnati have been assessed in a standard way to test language. As soon as a seizure is detected, the technologist or nurse comes into the room, presents the printed sign with a test sentence, and instructs the patient to read aloud until the sentence is read clearly and correctly. The test sentence is from the Boston Diagnostic Aphasia Test: “They heard him speak on the radio last night.” All patients are assessed for ability to read the test sentence between seizures during the initial EEG hookup. For the testing, every room has one or more 8.5 × 11-in. cards with 1-in. block letters; technologists and physicians carry smaller pocket versions. A single sentence is used because it is repeatable, and errors and speech disturbances can be more readily detected despite room noise or suboptimal audio recordings. Technologists have been trained to flash the test sign at the camera when the sentence is read correctly and state out loud when a patient makes a paraphasic error; these techniques further improve results in suboptimal audio situations. On many occasions, families can be instructed to effectively administer the testing. It appears that a patient memorizing the sentence has had no effect on results. The technique was initiated in 1988 with the goal of increasing detection of postictal paraphasic errors, because before that time, technologists and nurses often entered the room and had limited and inconsistent verbal interaction with the patient. Subsequently, we found several parameters with localizing value that are described below. Our current practice is to analyze the seizure recording for three parameters: (1) presence of paraphasic errors (ictal or postictal); (2)
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presence of formed ictal speech; and (3) postictal language delay (PILD). We calculate PILD as the time from the end of EEG ictal discharge to the time the patient reads the test sentence correctly. 3. Postictal language delay accurately lateralizes temporal lobe complex partial seizures An initial analysis of postictal language testing results showed remarkably accurate lateralization of TLCPSs [9]. Privitera et al. analyzed 105 seizures in 26 patients with seizure localization determined by postsurgical success. Postictal paraphasias were found in 46 of 62 seizures (11/14 patients). In all 62 left temporal seizures the language delay (PILD) was longer than 60 seconds (range: 68–1276 seconds). For 42 of 43 seizures from the right temporal lobe, the language delay was less than 60 seconds (range: 0–106 seconds) (Fig. 1). In this initial sample, using a cutoff of 60 seconds for PILD, 104 of 105 seizures were accurately lateralized. Interestingly, pure left mesial temporal simple partial seizures recorded with depth electrodes did not reveal impairment of language. These findings compared favorably with those of lateralization using other noninvasive methods like PET, MRI, and scalp EEG. From this analysis, we concluded that measuring PILD is the most accurate and reproducible method to test language in the ictal/ postictal period for patients with TLCPSs. 4. Atypical patterns of postictal language delay can identify patients with atypical language lateralization Postictal language patterns may be altered if patients have atypical localization of language function. Privitera et al. analyzed 64 patients with TLCPSs who underwent epilepsy surgery after an intracarotid amobarbital test (IAT) or direct electrocortical mapping [9]. Of 11 patients with IAT-proven right hemispheric or bilateral language dominance, 10 had “discordant” postictal language testing results. Postictal language patterns were classified as concordant or discordant with eventual epileptogenic focus localization using a PILD cutoff of 60 seconds derived from our initial study showing the high accuracy of this method [9]. Seizures were classified as concordant in patients with right TLCPSs if language delays b60 seconds occurred, whereas those with concordant left TLCPSs had language delays N60 seconds. Patients with discordant right TLCPSs had language delays N60 seconds, and those with discordant left TLCPSs had language delays b60 seconds. Patients with multiple seizures were classified as having a discordant postictal language pattern if any seizure showed a discordant language delay pattern. Discordant postictal language patterns were noted in 10 of 11 patients with IATdocumented nonleft language dominance and in 15 of 53 with left
Fig. 1. Graph demonstrating duration of postictal language delay (PILD) in right and left temporal lobe complex partial seizures. In this initial series, all but one seizure in one patient was correctly lateralized using a 60-second cutoff. Of 105 seizures, 104 were accurately lateralized with this cutoff.
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dominance (P = 0.006; sensitivity 90.9%, specificity 71.7%). In the 53 patients with left language dominance, postictal language testing correctly lateralized seizure onset in 38 patients (72%), was nonlateralizing in 10 (19%), and was falsely lateralizing in 5 (9%). 5. Postictal language delay patterns indicate onset or spread of seizures to the language-dominant temporal lobe Ficker et al. studied the effect of seizure spread from one temporal lobe to the other on postictal language patterns [10]. Fifteen of 40 patients who underwent prolonged video/EEG monitoring with intracranial depth electrodes from 1989 to 1997 had 69 TLCPSs that met the study criteria (29 nondominant and 40 dominant temporal onset). Typically, patients had six-contact depth electrodes inserted from a lateral approach under stereotactic guidance into bilateral amygdalar, hippocampal, and orbitofrontal regions. One patient had independent onset of seizures from both dominant and nondominant hemispheres. In two patients, some of their seizures propagated to the contralateral temporal lobe and some did not. All seizures had onset in the mesial temporal lobe. Fourteen of 15 patients had bilateral independent interictal spikes. Only two patients had hippocampal atrophy on MRI; the remainder of the patients had normal imaging studies. Seizures that began in the nondominant temporal lobe and propagated to the contralateral dominant temporal lobe were associated with a significantly longer PILD than seizures that did not propagate and were more likely to be associated with paraphasic errors (Table 1). Seven of 16 seizures that propagated from the nondominant temporal lobe to the dominant temporal lobe spread to the mesial temporal lobe structures only. The remaining nine seizures spread to both neocortical and mesial temporal lobe structures. All of the seizures that propagated from the dominant temporal lobe to the nondominant temporal lobe spread to the mesial temporal lobe structures only. PILD and paraphasic errors did not significantly differ between propagated and nonpropagated dominant-onset temporal lobe seizures. For seizures that originated in the nondominant temporal lobe and propagated to the dominant temporal lobe, a shorter propagation time was associated with a longer PILD (P b 0.01); however, the duration of electrographic seizure activity in the dominant temporal lobe (after propagation) did not influence PILD. There was no difference in postictal language behavior between propagated and nonpropagated dominant-onset temporal lobe seizures. These results indicate that ictal involvement of the dominant temporal lobe is the most important driver of postictal language behavior in TLCPSs. 6. Postictal language patterns can distinguish frontal from temporal lobe seizures and identify frontal-to-temporal spread patterns Goldberg-Stern et al. reported on postictal language patterns in 24 patients with 118 frontal lobe CPSs with or without spread to the
Table 1 Summary of postictal language data in seizures that spread from one temporal lobe to the other. Parameter
Nondominant TLCPSs (n=29) Dominant TLCPSs (n=40) Propagated (n = 16)
Mean (SD) postictal 443.0 language delay, s (389.8) Paraphasic errors 8/16
Not propagated (n = 13) 18.5 (19.6)a 0/13b
ipsilateral temporal lobe [11]. The diagnosis of frontal lobe CPSs was based on the presence of one of the following criteria: (1) the presence of frontal seizures as monitored by video/EEG in patients who underwent resection of a frontal lobe epileptogenic focus that resulted in a ≥90% decrease in seizure frequency during at least 2 years of followup (n = 2); (2) the presence of frontal seizures as monitored by video/ EEG in patients with frontal lobe anatomic lesions and medically intractable seizures who did not undergo surgical resection (n = 5); (3) the presence of frontal seizures as monitored with either subdural or depth electrodes in patients who did not undergo surgical resection (n = 17). All were right-handed, and language dominance was assessed by either IAT or direct cortical stimulation. Temporal spread was diagnosed if seizures arose in the frontal lobe and later spread to the temporal lobe during invasive EEG monitoring. If patients had only scalp EEG monitoring, temporal lobe spread was identified if frontal lobe seizure onset was recorded and followed by a late (N30 seconds after seizure onset), rhythmic, and N5-Hz temporal lobe ictal discharge. The seizures were categorized into four groups: (1) dominant frontal CPSs; (2) nondominant frontal CPSs; (3) dominant frontal onset CPSs with ipsilateral temporal spread; (4) nondominant frontal onset CPSs with ipsilateral temporal spread. Seizures originating from the dominant frontal lobe and spreading to the ipsilateral temporal lobe were associated with the longest PILD (median = 546.8 seconds) and were longer than CPSs confined to the dominant frontal lobe (median PILD = 30.2 seconds) (P = 0.0001). Prolonged PILD (defined as PILD N60 seconds) occurred in only 7% of CPSs confined to the dominant frontal lobe compared with 91% of CPSs that started as frontal and spread to the dominant temporal lobe (P b 0.0001). Seizures confined to the nondominant frontal lobe were associated with the shortest PILD (mean = 17.3 seconds). PILD was longer for seizures confined to the nondominant frontal lobe than for those originating in the nondominant frontal lobe and spreading to the ipsilateral temporal lobe (means = 30.2 and 23.6 seconds, respectively), but the difference did not reach statistical significance. Postictal language testing provides important information on frontal CPS localization and spread. To summarize the results in frontal lobe seizures, the postictal language findings are related primarily to seizure spread patterns. Prolonged postictal language dysfunction occurs when seizures originate or spread to the dominant temporal lobe and rarely with other cortical areas. Language patterns following dominant frontal-totemporal seizure spread appear indistinguishable from seizures that arise in the dominant temporal lobe. Dominant frontal lobe seizures differ greatly from nondominant temporal lobe seizures, rarely causing reading delay or paraphasias and sometimes showing ictal speech. Surprisingly, ictal reading without errors occurred in an equal number of seizures that were confined to the dominant and nondominant frontal lobes. The most remarkable finding was that the proximity of seizures to expressive language areas in the frontal lobe had no measurable effect on language measures. PILD changes
Table 2 Comparison of postictal language measures in dominant and nondominant seizures confined to frontal lobes compared with ipsilateral spread.
Propagated Not propagated (n = 19) (n = 21) 298.4 (459.8) 9/19
448.8 (425.6) 12/21
a P b 0.0001, GENMOD procedure, for propagated nondominant temporal lobe seizures. b P b 0.003, Fisher's exact test, for presence of paraphasic errors in propagated nondominant temporal lobe seizures.
Number of seizures Mean PILD Paraphasias PILD N 60 s Ictal reading a
Dominant
Nondominant
Dominant
Nondominant
FLa
FL
FL → TL
FL → TL
55 30.2 5% 7% 18%
24 17.3 0 0 16%
22 546.8 27% 90% 0
17 23.6 0 0 5%
FL, frontal lobe; TL, temporal lobe; PILD, postictal language delay.
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appear to be related to disruption of temporal lobe language networks and not a function of proximity of seizures to primary language areas (Table 2). 7. Speech prosody changes during nondominant temporal lobe complex partial seizures Patients with CPSs from the nondominant temporal lobe often read the test sentence during the ictal discharge. Paraphasic errors during the ictal discharge can occur with seizures from either temporal lobe; however a small number of patients with nondominant TLCPSs show alterations in speech prosody. Although these changes are usually obvious when listening to the audio during the seizure, speech prosody changes are difficult to quantify using accepted acoustical methods because of suboptimal recordings due to room noise, imperfect microphone localization, and other factors that are difficult to control in an epilepsy monitoring unit. Karolchyk et al. [12] reported on five subjects with nondominant TLCPSs who read the test sentence during the ictal discharge and had adequate acoustical quality for analysis. Acoustical analysis measured pitch, fundamental frequencies, and excursions. Three of the five subjects showed higher pitch and decreased excursions (flattened intonation). Boyce et al. [13] studied a single additional patient using more detailed acoustic analyses. They compared the patient's ictal speech while reading the test sentence with his own interictal (normal state) speech and also with 10 normal speakers’ fast and slow speech. The patient had right TLCPSs documented by video/EEG monitoring and subsequently had N90% seizure reduction after right anterior temporal lobectomy. IAT showed left hemisphere language dominance. Total duration (including pauses) was used as an index of speech rate. To measure “scanning” speech, the SI index suggested by Hertrich and Ackermann [14] was used. Vocal instabilities were measured visually from 1024-point narrow-band spectrograms as the number of short-duration fundamental frequency modulations over time. Four separate seizures were analyzed. Ictal speech showed a slower rate with a higher SI index, significantly more vocal instabilities, and isosynchrony. These findings had some similarities to ataxic speech. Overall, the findings from these two small studies indicate that patients with nondominant TLCPSs who are able to read during the ictal discharge show fairly consistent speech prosody changes with higher pitch, slower speed, somewhat flattened intonation, and a scanning quality. The rarity of these findings and the difficulty in analysis because of suboptimal recordings make the findings challenging to use for seizure localization. Nevertheless, without the standard postictal language testing method, these analyses would not have been possible. 8. Report of a “blurry sign” is highly associated with psychogenic nonepileptic seizures Lannon studied postictal language testing in a series of patients with psychogenic nonepileptic seizures identified with video/EEG monitoring who were tested using the Cincinnati method described above [15]. The test sentence is printed in large 1-in. block letters that are easy to read, so even patients who are not wearing usual corrective lenses can easily identify the words. Tapes of 31 consecutive patients diagnosed with only psychogenic events were analyzed and compared with those of 31 patients with CPSs (18 dominant/ 8 nondominant temporal lobe, 4 frontal, 1 occipital). In both groups the first event was used. Seventeen patients with psychogenic seizures responded either “I can't see it” or “It's blurry”; 14 read correctly. Twelve patients with CPSs read correctly (8 dominant, 4 frontal); one (occipital) said “I can't read it”; 18 (dominant) had a language delay N60 seconds, 8 with
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paraphasic errors. No patient with CPSs said “I can't see it” or “It's blurry”; patients with CPSs either read the sign with or without paraphasic errors or did not read at all. In the absence of seizures causing a postictal visual disturbance (typically occipital), the report that the sign is blurry in the postictal period is highly associated with psychogenic nonepileptic seizures. In this series, more than half the patients with psychogenic nonepileptic seizures reported that the sign was blurry. 9. Postictal language delay, postictal paraphasic errors, and interictal paraphasic errors have similar and additive diagnostic accuracy in lateralizing temporal lobe complex partial seizures Ramirez et al. studied 60 subjects who underwent inpatient video/ EEG monitoring and had surgically confirmed TLE to assess the relative performance of various language measures in seizure localization [16]. They determined the presence and number of postictal paraphasic errors and PILD times (in seconds) for 212 seizures and interictal paraphasic errors on the Boston Naming Test (BNT). Each technique's diagnostic usefulness was evaluated via logistic regression and receiver operating characteristic curve analysis. PILD, postictal paraphasic error production, and interictal paraphasic error production were equally effective and accurate in lateralizing TLCPS onset. Patients with dominant TLCPSs had a longer PILD and committed more postictal and interictal paraphasic errors than those with nondominant TLCPSs. Sensitivity and specificity values were as described in Table 3. No single predictor was significantly better, but a combination model yielded enough incremental utility to collectively outperform each separate predictor model. These more recent findings show that the Cincinnati method of language testing has high accuracy, but that accuracy can be improved when combined with interictal tests of language function (Table 3). 10. Age and presence of a structural lesion have little effect on postictal language delay Several case reports had suggested that older age or the presence of a structural lesion substantially increases language recovery time after seizures [17–19]. Goldberg-Stern et al. assessed the influence of age and a brain structural lesion on postictal language measures using the Cincinnati method for language testing [20]. They analyzed 173 seizures of 47 patients with TLCPSs (28 dominant, 19 nondominant). Age did not affect PILD regardless of the lateralization of the seizures. The presence of a structural lesion significantly prolonged PILD only in the patients with nondominant TLCPSs (P = 0.019). One limitation of the study was that the mean patient age was less than 40 years; although no obvious trend was seen in the results, different results may have been seen in a substantially older population. In addition, rare instances of very prolonged postictal language impairment may be seen in patients with dominant temporal lobe structural lesions. One of the authors (M.P.) has personal experience with two patients with dominant temporal lobe structural lesions, one a large stroke
Table 3 Comparison of diagnostic utilities for postictal language delay (PILD), postictal paraphasic errors (Post-PE), and interictal paraphasic errors (Inter-PE).
PILD Inter-PE Post-PE
Sensitivity
Specificity
Positive predictive value
Negative predictive value
84% 97% 94%
86% 86% 64%
87% 89% 75%
83% 96% 90%
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and the other a thrombosed arteriovenous malformation, both of whom experienced recurrent episodes of postictal aphasia with paraphasic errors lasting days to weeks after generalized tonic–clonic seizures. The EEG in these cases showed no evidence of aphasic status epilepticus. 11. Aphasic status epilepticus Postictal language delay must be differentiated from complex partial status epilepticus with aphasia. Aphasic status epilepticus may manifest with global, Broca, Wernicke, or mixed types of aphasia and include paraphasic errors [21–23]. PILD and paraphasic errors are defined as occurring after the EEG ictal discharge has ended. In the initial study of PILD, several patients were studied with both scalp and depth EEGs; the end of the EEG discharge was seen essentially simultaneously on scalp and depth EEG recordings [9]. Thus, scalp EEG in most cases appears to be sufficient to differentiate between aphasic status epilepticus and postictal language impairment. 12. Postictal “confusion” is most often a language disturbance and rarely interferes with adequate postictal language testing A frequent criticism of the postictal language testing method is that it will be confounded by postictal “confusion.” At the Cincinnati Epilepsy Center we have employed this testing method on several thousand patients since 1988 and found that “confusion” rarely impacts testing. Specifically for this review, we evaluated a sequential sample of 100 patients admitted to the epilepsy monitoring unit starting in January 2009 to determine how often adequate postictal language testing was performed. Excluded seizures were either psychogenic nonepileptic, tonic–clonic, simple partial, or electrographic. Ninety-one seizures (complex partial or absence) in 48 patients were reviewed. Adequate testing was performed in 79 (86.8%). Causes for inadequate testing were seizures that were missed by the observing technologist (n = 8), patient off camera (n = 1), isotope injection for ictal SPECT (n = 1), and confusion or agitation (n = 2). Thus, postictal agitation or confusion can occur in the epilepsy monitoring unit, but infrequently interferes with adequate postictal language testing. 13. Postictal visual field defects can occasionally be detected using the language test Infrequently patients with postictal hemianopsia are identified because they will read correctly only the words on the left or right half of the test sign. This has occurred solely with occipital seizures, and appears to be detectable only when there is a full hemianopsia and not merely a quadrantanopsia. 14. Limitations of postictal language testing The Cincinnati method for postictal language assessment is simple to apply and interpret, but there are limitations in its application. First, the patient must have adequate intelligence and visual function to be able to read the test sign at baseline. Second, adequate assessment of PILD generally requires testing to be initiated within 60 seconds of the end of the seizure. This requires vigilance by the technologist, nurse, or family member to rapidly identify a seizure and present the test sentence. However, if the test sign is presented after 60 seconds, the test is considered inadequate only if the patient reads the sentence on the first attempt without paraphasic errors. Third, language testing has not been adequately studied following tonic–clonic seizures primarily because it typically requires a minimum of 10–20 minutes for language function to return and it has not been feasible to have a technologist test for this duration, especially if the technologist is monitoring multiple patients at once.
Fourth, although “confusion” in the postictal state generally does not interfere with adequate testing, there are clearly situations where a patient has postictal agitation and the testing cannot be adequately performed. Fifth, no study of non-English speakers has been performed; however, at the Cincinnati Epilepsy Center we have translated the test sentence into several different languages and asked translators to review the recordings for accuracy and paraphasic errors. Finally, suboptimal audio recordings and room noise can interfere with detection of paraphasic errors and accurate assessment of the time of correct reading. We instruct technologists to state out loud when they hear a paraphasic error and to clearly identify when the patient reads the sentence correctly. 15. Summary Assessment of language function in the postictal state can be successfully performed and provides valuable information on seizure localization and spread. The Cincinnati method is a simple, repeatable test easily taught to technologists, nurses, and family members. It increases the yield of paraphasic errors and provides a quantitative measure of language recovery. This language testing method has been shown to lateralize TLCPSs, identify when TLCPSs spread to the dominant hemisphere, identify patients with atypical language lateralization, distinguish between temporal and frontal CPSs, and provide some insight into speech prosody changes in nondominant TLCPSs. This highly cost-effective test should be added to testing procedures in all epilepsy monitoring units.
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