- Email: [email protected]
Ictal nausea with vomiting as the major symptom of simple partial seizures: Electroencephalographic and magnetoencephalographic analysis
Available online at www.sciencedirect.com
Epilepsy & Behavior 11 (2007) 582–587 www.elsevier.com/locate/yebeh
Case Report
Ictal nausea with vomiting as the major symptom of simple partial seizures: Electroencephalographic and magnetoencephalographic analysis Masanori Sekimoto b
a,*
, Masaaki Kato a, Yu Kaneko b, Teiichi Onuma
a
a Musashino Kokubunji Clinic, Tokyo, Japan National Center Hospital for Mental, Nervous and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo, Japan
Received 1 July 2007; revised 24 August 2007; accepted 28 August 2007
Abstract Autonomic symptoms and signs rarely occur as isolated phenomena without impaired consciousness. Ictal nausea with vomiting is a rare clinical manifestation of seizures. Ictal vomiting is considered a localizing sign in patients with partial seizures of temporal origin. We encountered two patients with simple partial seizures that produced nausea with vomiting as the sole symptom, and we describe the interictal electroencephalographic and magnetoencephalographic findings. The episodes were paroxysmal and stereotypical in nature, and patients showed symptomatic response to a trial of antiepilepsy medication. In both patients, the diagnosis was simple partial seizures with autonomic symptomatology. Although interictal electroencephalography did not reveal focal spikes and focal slowing, estimated magnetoencephalographic dipoles were clustered in the parietal lobe. Interictal magnetoencephalographic foci may serve only as subsidiary evidence for the parietal origin of the episodes. However, our findings provide evidence of additional involvement of the parietal lobe in ictal vomiting. Ó 2007 Published by Elsevier Inc. Keywords: Ictal vomiting; Magnetoencephalogram; Electroencephalogram; Epilepsy; Simple partial seizure
1. Introduction Although autonomic symptoms and signs commonly accompany complex partial seizures, they rarely occur as isolated phenomena without impaired consciousness. Ictal nausea with vomiting is a rare clinical manifestation of seizures. Only a few reports have described isolated ictal vomiting without impaired awareness, except in cases of childhood abdominal epilepsy [1–3]. When nausea with vomiting is the sole seizure manifestation, nonepileptic conditions may be included in the differential diagnosis. Because of the unusual ictal symptomatology, nausea with
* Corresponding author. Address: Musashino Kokubunji Clinic, Minamicho Building 3F 3-22-31, Minamicho, Kokubunji, Tokyo 1850021, Japan. Fax: +81 42 328 5659. E-mail address: [email protected] (M. Sekimoto).
1525-5050/$ - see front matter Ó 2007 Published by Elsevier Inc. doi:10.1016/j.yebeh.2007.08.023
vomiting may often be masked and wrongly diagnosed as a nonepileptic event. We encountered two patients with simple partial seizures that produced nausea with vomiting as the sole symptom, and we report our interictal electroencephalography (EEG) and magnetoencephalography (MEG) findings. 2. Patients and methods 2.1. Interictal spike mapping by MEG MEG was performed in a magnetically shielded room (NKK Plant Engineering Corp., Tokyo, Japan) with a 204-channel whole-head neuromagnetometer (Neuromag Ltd., Helsinki, Finland) with 102 units comprising two orthogonal planar gradiometers. The sampling rate was 600 Hz, and the analog high-pass filter was set at 1.0 Hz. EEG was conducted simultaneously with 19 electrodes according to the International 10–20 System of Electrode Placement [4]. EEG lasted at least 30 minutes, so that sufficient interictal spikes could be recorded.
Case Report / Epilepsy & Behavior 11 (2007) 582–587 Each interictal spike was identified morphologically by visual inspection on both MEG and EEG waveforms. After a high-pass filter of 5 Hz was applied to remove DC shift, equivalent current dipoles were calculated from rising phase to peak latency at intervals of 1.7 ms (sampling rate). The dipole with the best goodness of fit was selected to represent the source of the interictal spike of interest. After as many dipoles as interictal spikes were collected by calculating one dipole from one spike, dipoles with goodness of fit exceeding 0.8 were chosen and overlaid onto magnetic resonance (MR) images. MR images were obtained with a 1.5-T system (Siemens AG., Munich, Germany) (140 slices, thickness = 1.5 mm).
583
iting and heart palpitations without altered awareness. These episodes lasted several minutes and occurred once or twice a month. When these episodes occurred in the office, he stopped work for a while. Gastrointestinal disease was ruled out. Interictal single-photon emission computed tomography (SPECT) revealed an area of slight hypoperfusion in the left occipital lobe. Brain MR imaging findings were unremarkable. Interictal EEG revealed bilateral low-voltage spikes in the occipital and parietal regions, with frontal dominant low-voltage slow waves (Fig. 1). Attempts to record ictal EEG were unsuccessful despite prolonged recording. Interictal MEG revealed a bilateral dipole in the parietal region (Fig. 2). The patient has been seizure-free for 3 years after the start of carbamazepine therapy (600 mg/day with a serum concentration of 6.7–8.3 lg/mL).
2.2. Case reports 2.2.1. Patient 1 A 32-year-old right-handed man was referred to us because of vomiting attacks. The patient was the product of a normal pregnancy and delivery, and his development was normal. He had never had febrile convulsions. His mother was diagnosed with epilepsy before the patient was born and was being treated with antiepileptic drugs. At age 22, he started having sudden, stereotyped episodes of nausea, followed by vom-
2.2.2. Patient 2 A 23-year-old right-handed woman was referred to us because of intractable nausea and vomiting. The patient was the product of a normal pregnancy and delivery, and her development was normal. Her family history was unremarkable. She suffered generalized tonic–clonic seizures with loss of consciousness at age 12. From ages 12 to 16, she received valproate monotherapy. Because of the absence of seizures, the medication was discontinued 7 years before her visit. She started having sudden nausea and
Fig. 1. Interictal EEG recording shows low voltage spikes predominantly in the bilateral occipital and right parietal regions. AV indicates average potential reference.
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Case Report / Epilepsy & Behavior 11 (2007) 582–587
Fig. 2. MEG channels in the parietal region show spikes synchronizing with EEG. Dipole co-registration to MR imaging and 3-D imaging revealed dipoles located in the left and right parietal regions.
Case Report / Epilepsy & Behavior 11 (2007) 582–587 vaguely unpleasant feelings, followed by vomiting without loss of consciousness, 5 months before her visit. These episodes lasted several minutes and occurred once a month. When these episodes occurred in the streetcar, she got off at the next station and took a rest. Interictal SPECT revealed an area of slight hypoperfusion in the left frontal lobe. Brain MR imaging findings were unremarkable. Interictal EEG revealed bilateral frontopolar-frontal dominant delta bursts accompanied by low-voltage spikes in the parietal and occipital regions (Fig. 3). Attempts to record ictal EEG were unsuccessful despite prolonged recording. Interictal MEG revealed a dipole in the left parietal region (Fig. 4). The patient has been seizurefree for 4 years after the start of carbamazepine therapy (300 mg/day with a serum concentration of 3.7–5.3 lg/mL).
3. Discussion A diagnosis of simple autonomic seizures is difficult to establish, particularly when nausea with vomiting is the sole objective sign. Although the presence of ictal EEG discharges during a typical event would have the diagnosis of
585
autonomic seizures in the cases described here, we could not capture a typical event because of the infrequent occurrence of seizures. The episodes were paroxysmal and stereotypical in nature, and the patients showed symptomatic response to a trial of antiepilepsy medication. Therefore, the diagnosis was simple partial seizures with autonomic symptomatology. As for patient 2, the clinical history at age 12 is lacking in detail, so that it is not certain whether the seizures at age 12 were generalized seizures or partial seizures with secondary generalization. Ictal vomiting is often accompanied by impaired consciousness and drooling [5]; isolated ictal vomiting as the sole symptom without impaired awareness is rare. Most simple partial seizures do not have scalp electrographic correlates; the absence of any scalp correlate is probably due to multiple factors, most notably lack of sensitivity of scalp EEG to ictal discharges in buried cortex or
Fig. 3. Interictal EEG recording shows diffuse rhythmic slow waves predominantly in both frontopolar-frontal regions and low-voltage spikes predominantly in the left parietal and both occipital regions. AV indicates average potential reference.
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Case Report / Epilepsy & Behavior 11 (2007) 582–587
Fig. 4. MEG spikes were identified by sensors covering the left parietal area. Dipole co-registration to MR imaging and 3-D imaging revealed dipoles located in the left parietal region.
small tissue volume [6]. Devinsky et al. [7] used video/EEG telemetry to evaluate the clinical and electrographic features of 87 simple partial seizures in 14 patients. Twentysix seizures (30%) were classified as simple autonomic seizures. Of the 87 simple partial seizures, only 18 seizures (21%) were characterized by ictal EEG changes. There are few reports of ictal EEG during vomiting without impaired consciousness [1,3]. Mitchell et al. [1] reported ictal EEG that showed bihemispheric slowing with delta and theta bursts and runs of high-voltage, sharply contoured, 1- to 2-Hz activity over the right temporal area in cases of childhood abdominal epilepsy. In contrast, a few studies have analyzed ictal and interictal MEG recordings of simple partial seizures with autonomic symptoms [8]. However, there are few reports of MEG of simple partial seizures with ictal nausea and vomiting. Although interictal EEG in our two patients did not show focal spikes and focal slowing, MEG in these patients revealed interictal spikes and the estimated dipoles were clustered in the parietal lobe. Ictal vomiting is considered a localizing sign in patients with partial seizures of temporal origin [9]. Ictal vomiting in patients with focal epilepsy has been associated with an epileptogenic zone in the non-language-dominant hemisphere [10–12]. However, ictal vomiting can occur as a manifestation of left temporal onset seizures in left hemi-
sphere-dominant patients [3,13,14]. Thus, the findings on hemisphere lateralization are not consistent. In contrast, although the findings are not consistent, several studies have reported that the insula and lateral temporal cortex are associated with vomiting [10,15]. Penfield and Jasper [15] observed that electrical stimulation of the insular cortex caused patients to experience a sensation of nausea and suggested that this region may be associated with the visceromotor function necessary for vomiting. Kramer et al. [10], through subdural electrocorticography, demonstrated that ictal vomiting was not seen in association with mesial temporal onset seizures until propagation to the lateral temporal neocortex occurred. In our patients, the temporal lobes were not apparently responsible for ictal nausea and vomiting in light of interictal EEG and MEG data and imaging data. The seizure symptoms of parietal lobe epilepsy are of varying localizing and lateralizing value; seizure discharges may spread rapidly, and perceived symptoms may reflect secondary spread rather than the primary site of seizure onset [16]. In addition, there is frequently poor correlation between clinical and EEG features [16]. It is not certain whether the parietal lobe in which the estimated dipoles were clustered was responsible for the ictal nausea and vomiting in our patients. However, in light of reported findings, it is probable that seizure discharges in the parie-
Case Report / Epilepsy & Behavior 11 (2007) 582–587
tal area spread rapidly, stimulating the insular or lateral temporal cortex and resulting in ictal vomiting. Moreover, whether the throat is represented on the parietal lobe is not clear, and the possibility that the region that corresponds to the pharynx in the sensory area of the parietal lobe is responsible for ictal vomiting requires further examination. Although interictal MEG foci may serve only as subsidiary evidence for the parietal origin of the episodes, our findings provide evidence of the additional involvement of the parietal lobe in ictal vomiting. References [1] Mitchell WG, Greenwood RS, Messenheimer JA. Abdominal epilepsy: cyclic vomiting as the major symptom of simple partial seizures. Arch Neurol 1983;40:251–2. [2] Prensky AL. An approach to the child with paroxysmal phenomenon with emphasis on nonepileptic disorders. In: Dodson WE, Pellock JM, editors. Pediatric epilepsy: diagnosis and therapy. New York: Demos; 1993. [3] Chen C, Yen DJ, Yiu CH, Shih YH, Yu HY, Su MS. Ictal vomiting in partial seizures of temporal lobe origin. Eur Neurol 1999;42:235–9. [4] Klem GH, Luders HO, Jasper HH, Elger C. The International Federation of Clinical Neurophysiology. The ten–twenty electrode system of the International Federation. Electroencephalogr Clin Neurophysiol Suppl 1999;52:3–6. [5] Jacome DE, FitzGerald R. Ictus emeticus. Neurology 1982;32:209–12.
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[6] Liporace JD, Sperling MR. Simple autonomic seizures. In: Engel J, Pedley TA, editors. Epilepsy: a comprehensive textbook. Philadelphia: Lippincott-Raven; 1997. p. 549–55. [7] Devinsky O, Kelley K, Porter RJ, Theodore WH. Clinical and electroencephalographic features of simple partial seizures. Neurology 1988;38:1347–52. [8] Stefan H, Feichtinger M, Genow A, Kerling F. Goose flesh and cold sensation: symptoms of visceral epilepsy. Nervenarzt 2002;73:188–93. [9] Fiol ME, Leppik IE, Mireles R, Maxwell R. Ictus emeticus and the insular cortex. Epilepsy Res 1988;2:127–31. [10] Kramer RE, Luders H, Goldstick LP, et al. Ictus emeticus: an electroclinical analysis. Neurology 1988;38:1048–52. [11] Devinsky O, Frasca J, Pacia SV, Luciano DJ, Paraiso J, Doyle W. Ictus emeticus: further evidence of nondominant temporal involvement. Neurology 1995;45:1158–60. [12] Baumgartner C, Olbrich A, Lindinger G, et al. Regional cerebral blood flow during temporal lobe seizures associated with ictal vomiting: an ictal SPECT study in two patients. Epilepsia 1999;40:1085–91. [13] Schauble B, Britton JW, Mullan BP, Watson J, Sharbrough FW, Marsh WR. Ictal vomiting in association with left temporal lobe seizures in a left hemisphere language-dominant patient. Epilepsia 2002;43:1432–5. [14] Schindler K, Wieser HG. Ictal vomiting in a left hemisphere language-dominant patient with left-sided temporal lobe epilepsy. Epilepsy Behav 2006;8:323–7. [15] Penfield W, Jasper H. Alimentary seizures. In: Epilepsy and the functional anatomy of the human brain. Boston: Little Brown; 1954. p. 412–37. [16] Sveinbjornsdottir S, Duncan JS. Parietal and occipital lobe epilepsy: a review. Epilepsia 1993;34:493–521.
Epilepsy & Behavior 11 (2007) 582–587 www.elsevier.com/locate/yebeh
Case Report
Ictal nausea with vomiting as the major symptom of simple partial seizures: Electroencephalographic and magnetoencephalographic analysis Masanori Sekimoto b
a,*
, Masaaki Kato a, Yu Kaneko b, Teiichi Onuma
a
a Musashino Kokubunji Clinic, Tokyo, Japan National Center Hospital for Mental, Nervous and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo, Japan
Received 1 July 2007; revised 24 August 2007; accepted 28 August 2007
Abstract Autonomic symptoms and signs rarely occur as isolated phenomena without impaired consciousness. Ictal nausea with vomiting is a rare clinical manifestation of seizures. Ictal vomiting is considered a localizing sign in patients with partial seizures of temporal origin. We encountered two patients with simple partial seizures that produced nausea with vomiting as the sole symptom, and we describe the interictal electroencephalographic and magnetoencephalographic findings. The episodes were paroxysmal and stereotypical in nature, and patients showed symptomatic response to a trial of antiepilepsy medication. In both patients, the diagnosis was simple partial seizures with autonomic symptomatology. Although interictal electroencephalography did not reveal focal spikes and focal slowing, estimated magnetoencephalographic dipoles were clustered in the parietal lobe. Interictal magnetoencephalographic foci may serve only as subsidiary evidence for the parietal origin of the episodes. However, our findings provide evidence of additional involvement of the parietal lobe in ictal vomiting. Ó 2007 Published by Elsevier Inc. Keywords: Ictal vomiting; Magnetoencephalogram; Electroencephalogram; Epilepsy; Simple partial seizure
1. Introduction Although autonomic symptoms and signs commonly accompany complex partial seizures, they rarely occur as isolated phenomena without impaired consciousness. Ictal nausea with vomiting is a rare clinical manifestation of seizures. Only a few reports have described isolated ictal vomiting without impaired awareness, except in cases of childhood abdominal epilepsy [1–3]. When nausea with vomiting is the sole seizure manifestation, nonepileptic conditions may be included in the differential diagnosis. Because of the unusual ictal symptomatology, nausea with
* Corresponding author. Address: Musashino Kokubunji Clinic, Minamicho Building 3F 3-22-31, Minamicho, Kokubunji, Tokyo 1850021, Japan. Fax: +81 42 328 5659. E-mail address: [email protected] (M. Sekimoto).
1525-5050/$ - see front matter Ó 2007 Published by Elsevier Inc. doi:10.1016/j.yebeh.2007.08.023
vomiting may often be masked and wrongly diagnosed as a nonepileptic event. We encountered two patients with simple partial seizures that produced nausea with vomiting as the sole symptom, and we report our interictal electroencephalography (EEG) and magnetoencephalography (MEG) findings. 2. Patients and methods 2.1. Interictal spike mapping by MEG MEG was performed in a magnetically shielded room (NKK Plant Engineering Corp., Tokyo, Japan) with a 204-channel whole-head neuromagnetometer (Neuromag Ltd., Helsinki, Finland) with 102 units comprising two orthogonal planar gradiometers. The sampling rate was 600 Hz, and the analog high-pass filter was set at 1.0 Hz. EEG was conducted simultaneously with 19 electrodes according to the International 10–20 System of Electrode Placement [4]. EEG lasted at least 30 minutes, so that sufficient interictal spikes could be recorded.
Case Report / Epilepsy & Behavior 11 (2007) 582–587 Each interictal spike was identified morphologically by visual inspection on both MEG and EEG waveforms. After a high-pass filter of 5 Hz was applied to remove DC shift, equivalent current dipoles were calculated from rising phase to peak latency at intervals of 1.7 ms (sampling rate). The dipole with the best goodness of fit was selected to represent the source of the interictal spike of interest. After as many dipoles as interictal spikes were collected by calculating one dipole from one spike, dipoles with goodness of fit exceeding 0.8 were chosen and overlaid onto magnetic resonance (MR) images. MR images were obtained with a 1.5-T system (Siemens AG., Munich, Germany) (140 slices, thickness = 1.5 mm).
583
iting and heart palpitations without altered awareness. These episodes lasted several minutes and occurred once or twice a month. When these episodes occurred in the office, he stopped work for a while. Gastrointestinal disease was ruled out. Interictal single-photon emission computed tomography (SPECT) revealed an area of slight hypoperfusion in the left occipital lobe. Brain MR imaging findings were unremarkable. Interictal EEG revealed bilateral low-voltage spikes in the occipital and parietal regions, with frontal dominant low-voltage slow waves (Fig. 1). Attempts to record ictal EEG were unsuccessful despite prolonged recording. Interictal MEG revealed a bilateral dipole in the parietal region (Fig. 2). The patient has been seizure-free for 3 years after the start of carbamazepine therapy (600 mg/day with a serum concentration of 6.7–8.3 lg/mL).
2.2. Case reports 2.2.1. Patient 1 A 32-year-old right-handed man was referred to us because of vomiting attacks. The patient was the product of a normal pregnancy and delivery, and his development was normal. He had never had febrile convulsions. His mother was diagnosed with epilepsy before the patient was born and was being treated with antiepileptic drugs. At age 22, he started having sudden, stereotyped episodes of nausea, followed by vom-
2.2.2. Patient 2 A 23-year-old right-handed woman was referred to us because of intractable nausea and vomiting. The patient was the product of a normal pregnancy and delivery, and her development was normal. Her family history was unremarkable. She suffered generalized tonic–clonic seizures with loss of consciousness at age 12. From ages 12 to 16, she received valproate monotherapy. Because of the absence of seizures, the medication was discontinued 7 years before her visit. She started having sudden nausea and
Fig. 1. Interictal EEG recording shows low voltage spikes predominantly in the bilateral occipital and right parietal regions. AV indicates average potential reference.
584
Case Report / Epilepsy & Behavior 11 (2007) 582–587
Fig. 2. MEG channels in the parietal region show spikes synchronizing with EEG. Dipole co-registration to MR imaging and 3-D imaging revealed dipoles located in the left and right parietal regions.
Case Report / Epilepsy & Behavior 11 (2007) 582–587 vaguely unpleasant feelings, followed by vomiting without loss of consciousness, 5 months before her visit. These episodes lasted several minutes and occurred once a month. When these episodes occurred in the streetcar, she got off at the next station and took a rest. Interictal SPECT revealed an area of slight hypoperfusion in the left frontal lobe. Brain MR imaging findings were unremarkable. Interictal EEG revealed bilateral frontopolar-frontal dominant delta bursts accompanied by low-voltage spikes in the parietal and occipital regions (Fig. 3). Attempts to record ictal EEG were unsuccessful despite prolonged recording. Interictal MEG revealed a dipole in the left parietal region (Fig. 4). The patient has been seizurefree for 4 years after the start of carbamazepine therapy (300 mg/day with a serum concentration of 3.7–5.3 lg/mL).
3. Discussion A diagnosis of simple autonomic seizures is difficult to establish, particularly when nausea with vomiting is the sole objective sign. Although the presence of ictal EEG discharges during a typical event would have the diagnosis of
585
autonomic seizures in the cases described here, we could not capture a typical event because of the infrequent occurrence of seizures. The episodes were paroxysmal and stereotypical in nature, and the patients showed symptomatic response to a trial of antiepilepsy medication. Therefore, the diagnosis was simple partial seizures with autonomic symptomatology. As for patient 2, the clinical history at age 12 is lacking in detail, so that it is not certain whether the seizures at age 12 were generalized seizures or partial seizures with secondary generalization. Ictal vomiting is often accompanied by impaired consciousness and drooling [5]; isolated ictal vomiting as the sole symptom without impaired awareness is rare. Most simple partial seizures do not have scalp electrographic correlates; the absence of any scalp correlate is probably due to multiple factors, most notably lack of sensitivity of scalp EEG to ictal discharges in buried cortex or
Fig. 3. Interictal EEG recording shows diffuse rhythmic slow waves predominantly in both frontopolar-frontal regions and low-voltage spikes predominantly in the left parietal and both occipital regions. AV indicates average potential reference.
586
Case Report / Epilepsy & Behavior 11 (2007) 582–587
Fig. 4. MEG spikes were identified by sensors covering the left parietal area. Dipole co-registration to MR imaging and 3-D imaging revealed dipoles located in the left parietal region.
small tissue volume [6]. Devinsky et al. [7] used video/EEG telemetry to evaluate the clinical and electrographic features of 87 simple partial seizures in 14 patients. Twentysix seizures (30%) were classified as simple autonomic seizures. Of the 87 simple partial seizures, only 18 seizures (21%) were characterized by ictal EEG changes. There are few reports of ictal EEG during vomiting without impaired consciousness [1,3]. Mitchell et al. [1] reported ictal EEG that showed bihemispheric slowing with delta and theta bursts and runs of high-voltage, sharply contoured, 1- to 2-Hz activity over the right temporal area in cases of childhood abdominal epilepsy. In contrast, a few studies have analyzed ictal and interictal MEG recordings of simple partial seizures with autonomic symptoms [8]. However, there are few reports of MEG of simple partial seizures with ictal nausea and vomiting. Although interictal EEG in our two patients did not show focal spikes and focal slowing, MEG in these patients revealed interictal spikes and the estimated dipoles were clustered in the parietal lobe. Ictal vomiting is considered a localizing sign in patients with partial seizures of temporal origin [9]. Ictal vomiting in patients with focal epilepsy has been associated with an epileptogenic zone in the non-language-dominant hemisphere [10–12]. However, ictal vomiting can occur as a manifestation of left temporal onset seizures in left hemi-
sphere-dominant patients [3,13,14]. Thus, the findings on hemisphere lateralization are not consistent. In contrast, although the findings are not consistent, several studies have reported that the insula and lateral temporal cortex are associated with vomiting [10,15]. Penfield and Jasper [15] observed that electrical stimulation of the insular cortex caused patients to experience a sensation of nausea and suggested that this region may be associated with the visceromotor function necessary for vomiting. Kramer et al. [10], through subdural electrocorticography, demonstrated that ictal vomiting was not seen in association with mesial temporal onset seizures until propagation to the lateral temporal neocortex occurred. In our patients, the temporal lobes were not apparently responsible for ictal nausea and vomiting in light of interictal EEG and MEG data and imaging data. The seizure symptoms of parietal lobe epilepsy are of varying localizing and lateralizing value; seizure discharges may spread rapidly, and perceived symptoms may reflect secondary spread rather than the primary site of seizure onset [16]. In addition, there is frequently poor correlation between clinical and EEG features [16]. It is not certain whether the parietal lobe in which the estimated dipoles were clustered was responsible for the ictal nausea and vomiting in our patients. However, in light of reported findings, it is probable that seizure discharges in the parie-
Case Report / Epilepsy & Behavior 11 (2007) 582–587
tal area spread rapidly, stimulating the insular or lateral temporal cortex and resulting in ictal vomiting. Moreover, whether the throat is represented on the parietal lobe is not clear, and the possibility that the region that corresponds to the pharynx in the sensory area of the parietal lobe is responsible for ictal vomiting requires further examination. Although interictal MEG foci may serve only as subsidiary evidence for the parietal origin of the episodes, our findings provide evidence of the additional involvement of the parietal lobe in ictal vomiting. References [1] Mitchell WG, Greenwood RS, Messenheimer JA. Abdominal epilepsy: cyclic vomiting as the major symptom of simple partial seizures. Arch Neurol 1983;40:251–2. [2] Prensky AL. An approach to the child with paroxysmal phenomenon with emphasis on nonepileptic disorders. In: Dodson WE, Pellock JM, editors. Pediatric epilepsy: diagnosis and therapy. New York: Demos; 1993. [3] Chen C, Yen DJ, Yiu CH, Shih YH, Yu HY, Su MS. Ictal vomiting in partial seizures of temporal lobe origin. Eur Neurol 1999;42:235–9. [4] Klem GH, Luders HO, Jasper HH, Elger C. The International Federation of Clinical Neurophysiology. The ten–twenty electrode system of the International Federation. Electroencephalogr Clin Neurophysiol Suppl 1999;52:3–6. [5] Jacome DE, FitzGerald R. Ictus emeticus. Neurology 1982;32:209–12.
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[6] Liporace JD, Sperling MR. Simple autonomic seizures. In: Engel J, Pedley TA, editors. Epilepsy: a comprehensive textbook. Philadelphia: Lippincott-Raven; 1997. p. 549–55. [7] Devinsky O, Kelley K, Porter RJ, Theodore WH. Clinical and electroencephalographic features of simple partial seizures. Neurology 1988;38:1347–52. [8] Stefan H, Feichtinger M, Genow A, Kerling F. Goose flesh and cold sensation: symptoms of visceral epilepsy. Nervenarzt 2002;73:188–93. [9] Fiol ME, Leppik IE, Mireles R, Maxwell R. Ictus emeticus and the insular cortex. Epilepsy Res 1988;2:127–31. [10] Kramer RE, Luders H, Goldstick LP, et al. Ictus emeticus: an electroclinical analysis. Neurology 1988;38:1048–52. [11] Devinsky O, Frasca J, Pacia SV, Luciano DJ, Paraiso J, Doyle W. Ictus emeticus: further evidence of nondominant temporal involvement. Neurology 1995;45:1158–60. [12] Baumgartner C, Olbrich A, Lindinger G, et al. Regional cerebral blood flow during temporal lobe seizures associated with ictal vomiting: an ictal SPECT study in two patients. Epilepsia 1999;40:1085–91. [13] Schauble B, Britton JW, Mullan BP, Watson J, Sharbrough FW, Marsh WR. Ictal vomiting in association with left temporal lobe seizures in a left hemisphere language-dominant patient. Epilepsia 2002;43:1432–5. [14] Schindler K, Wieser HG. Ictal vomiting in a left hemisphere language-dominant patient with left-sided temporal lobe epilepsy. Epilepsy Behav 2006;8:323–7. [15] Penfield W, Jasper H. Alimentary seizures. In: Epilepsy and the functional anatomy of the human brain. Boston: Little Brown; 1954. p. 412–37. [16] Sveinbjornsdottir S, Duncan JS. Parietal and occipital lobe epilepsy: a review. Epilepsia 1993;34:493–521.