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Childhood occipital epilepsy: seizure manifestations and electroencephalographic features
ELSEVIER
Brain & Development 19 (1997) 408-413
Original article
Childhood occipital epilepsy: seizure manifestations and electroencephalographic features A. Destina Yalqln*, Asuman
Kaymaz, Hulki Forta
Department of Neurology, ~i~li Etfal Education Hospital, ~i¢li, istanbul, Turkey Received 3 December 1996; revised version received 3 July 1997; accepted 10 July 1997
Abstract Childhood epilepsy with occipital paroxysms (CEOP) is an idiopathic localization-related epilepsy. A typical seizure in CEOP begins with visual symptoms, followed by hemiclonic seizures, complex partial seizures or generalized tonic-clonic seizures. Benign nocturnal childhood occipital epilepsy (BNCOE), characterized by nocturnal seizures with tonic deviation of the eyes followed by vomiting, has the same electroencephalographic features as CEOP. In this study, we report the seizure symptoms and electroencephalographic features of 21 cases with CEOP or BNCOE. Out of these patients, nine had BNCOE, six had CEOP, four had CEOP and BNCOE and the remaining two belonged to the incomplete syndrome because of no paroxysmal discharges in EEG. When the patients with BNCOE awoke from sleep, they had tonic deviation of the eyes and could describe visual symptoms. Patients with CEOP had seizures beginning with visual symptoms followed by loss of consciousness but no generalized convulsions. In three cases, in addition to the occipital spikes, independent centrotemporal spikes were recorded and in another three cases generalized spike-wave discharges were recorded. Such a combination suggests the idiopathic nature of these epilepsies. We concluded that in the diagnosis of CEOP and BNCOE, the seizure symptomatology is important even if the EEG can be considered normal. © 1997 Elsevier Science B.V. Keywords: Childhood epilepsy with occipital paroxysms; Benign nocturnal childhood occipital epilepsy; Seizure symptomatology
1. Introduction Childhood epilepsy with occipital paroxysms (CEOP) is established as an idiopathic localization-related epilepsy in the International Classification of the Epilepsies, Epileptic Syndromes and Related Seizure Disorders. A typical seizure in CEOP begins with visual symptoms, followed by hemiclonic seizures, complex partial seizures and generalized tonic-clonic seizures [1]. On the other hand, benign nocturnal childhood occipital epilepsy (BNCOE), characterized by nocturnal seizures with tonic deviation of the eyes followed by vomiting, has the same electroencephalographic features as CEOP [2]. The EEG typically shows spikes or sharp waves in the occipital and posterotemporal regions. The spikes usually appear rhythmically at a frequency of 1-3 *Corresponding author. Selquklar Sokak, 51/14, Akatlar, 80630, |stanbul, Turkey. TeL/fax: +90 212 2793124.
0387-7604/97/$17.00 © 1997 Elsevier Science B.V. All rights reserved PII S0387-7604(97)00054-5
Hz in bursts or trains. The paroxysms are characteristically suppressed or strikingly reduced by eye opening [3]. This EEG pattern has also been observed in patients with basilar artery migraine and in children without paroxysmal phenomena [4-6]. The same EEG pattern can be found in cases with symptomatic epilepsy, for example in patients with bilateral occipital corticosubcortical calcifications without any sign of phakomatosis [7]. In this study, we report the seizure symptoms and electroencephalographic features of 21 cases with CEOP or BNCOE.
2. Patients and methods In this study, patients who had seizures with occipital spikes in EEG and who were followed by the Epilepsy Outpatient Clinic of ~i~li Etfal Education Hospital, Istanbul were screened. Nineteen patients who fulfilled the following
A.D. Yal~m et al. /Brain & Development 19 (1997) 408-413
409
Table 1 Seizure symptomatology and electroencephalographic features of the patients Patient/sex/age (years) at last review
Age at firsl seizure (years)
Age at last seizure (years)
Seizure number (nocturnal/diurnal)
Seizure symptomatology
EEG
1/M/6 2/M/10 3/M/5.5 4/M/7 5/F/7 6/M/12 7/F/6 8/M/10 9/M/11 10/F/15 ll/M/14 12/M/17 13/M/23 14/F/7 15/F/14 16/M/10 17/M/11 18/M/14 19/F/17 20/F/13 21/F/15
5 3 2.5 3 5 7 5 6 7 10 12 5 11 1.5 13 9 9 11 16 12 12
5 3 3 6 5 8 5 6.5 7.5 13 14 17 23 5 13 9.5 9 14 17 12 15
2N 3N 3N Many N 2N 2N 3N 3N 2N Many D 9D Many D Many D 3D 4D 1N/3D 1N/3D 3N/many D 2N/2D 4D 3N
AS, ED, B, LOC, H GC AS, ED, BV, LOC, V HC AS, ED, VH, LOC, V GC GC AS, ED, B, V, LOC AS, ED, VH, LOC BV, ED, LOC, HFC B, ED, LOC, V, H BV, ED, LOC B, VH, ED, V, LOC, H VH, ED, V, H, LOC BV, ED, V, LOC, HFC, H N: AS, ED, BV, LOC; D: PLOC, A N: GC; D: VH, ED, LOC N: AS, BV, VH, ED, LOC; D: BV, VH, ED, LOC N: GC; D: VH, ED, LOC B, ED, LOC, V, HFC, H AS, VH, ED, LOC, V
L Oc Bil Oc R Oc, Gen L Oc, L CT Bil Oc Bil Oc, R CT L Oc, Gen R Oc L Oc Bil Oc R Oc R Oc R Oc Bil Oc, Gen L Oc L Oc, R CT L Oc L Oc L Oc nl nl
AS, awakening from sleep; ED, deviation of the eyes; B, blindness; LOC, loss of consciousness; H, headache; GC, generalized convulsion; BV, blurred vision; V, vomiting; VH, visual hallucination; HFC, hemifacial convulsion; PLOC, prolonged loss of consciousness; A, automatism; L Oc, left occipital spike-wave; R Oc, right occipital spike-wave; Bil Oc, bilateral occipital spike-wave; L CT, left centrotemporal spike; R CT, right centrotemporal spike; Gen, generalized spike-wave; nl, normal.
criteria were included in the study: (1) diurnal or nocturnal seizures associated with occipital spikes or spike-waves in the EEG, suppressed by eye opening; (2) onset of seizures before 17 years of age; and (3) normal computed tomo-
graphic (CT) brain scan or magnetic resonance imaging (MRI). The following patients were excluded: (1) patients with occipital spikes or spike-waves who had myoclonic, photo-
Table 2 Neurological findings, response to antiepileptic drug treatment and family history of the patients Patient
Neurologic findings
Antiepileptic drugs
1
PSP Normal PSP Normal Normal PSP Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal
No CBZ CBZ CBZ CBZ CBZ No No PB CBZ PT VA PT CBZ CBZ PT CBZ CBZ CBZ PT CBZ
2 3
4 5 6
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Seizure frequency under treatment
Rare -
Rare Rare Rare Rare Rare Rare Rare -
Years without medication
Family history of seizures or febrile convulsions
-
Yes Yes No No Yes No Yes Yes No No No No No No No No No Yes (FC) No Yes No
3 1 -
PSP, poor school performance; CBZ, carbamazepine; PB, phenobarbital; PT, phenytoin; VA, valproic acid; FC, febrile convulsion.
410
A.D. Yal¢m et al. / Brain & Development 19 (1997) 408-413
sensitive, absence or Rolandic epilepsy; (2) patients with occipital paroxysms and febrile convulsion; and (3) patients with symptomatic epilepsy and occipital spikes. In addition to 19 patients who fulfilled the above criteria, two patients with typical ictal visual symptoms but normal EEG findings were included. The ictal symptomatology was assessed from the descriptions of the patients and their parents. In addition to their regular visits every 2 months, the patients were asked to visit our Epilepsy Outpatient Clinic as soon as possible after each seizure to report the details of the seizure symptoms.
3. Results Nine patients had only nocturnal seizures and were classified as BNCOE (Table 1, patients 1-9). In three patients the seizures were described as tonic-clonic convulsion and in one as hemiconvulsion. These patients were unconscious during the seizure. Tonic deviation of the eyes was observed in five children. All these patients awoke from sleep and could describe visual symptoms; three reported blindness or blurred vision and the rest colorful moving spots. In these patients if the seizure lasted a few minutes, consciousness was not impaired and the patients were able to speak with their parents. However, when seizures were prolonged, deviation of the eyes continued and the patient became unconscious. Vomiting was observed in three patients. Three of our patients had difficulties at school; according to their teachers their performance at school was poor compared to that of their classmates. One of these patients, a 12year-old boy, required additional private lessons. The seizure frequency was low and the seizures responded well to treatment. Only one patient had rare seizures under treatment, while the others with or without treatment stayed seizure-free (Table 2). Six patients had CEOP (Table 1, patients 10-15). These patients had only diurnal seizures which always began with visual symptoms. These symptoms were described as partial or complete blurred vision of the entire or partial visual field in four patients and as moving or flashing colored spots or circles in one patient. One patient described both ictal visual symptoms. All these patients also had tonic deviation of the eyes. None of these patients had convulsive phenomena although consciousness was impaired or lost during the seizures in all cases. Vomiting was observed in four patients. In all patients mental development was normal. The seizure frequency was variable, but high compared to patients who had only nocturnal seizures (Table 1). Four patients had diurnal as well as nocturnal seizures and were classified as having CEOP and BNCOE (Table 1, patients 16-19). In one child complex partial seizures with automatism and prolonged unconsciousness were
noted three times. Although all of the EEGs recorded were normal, two patients had seizures with ictal visual symptoms; one had four diurnal seizures with blindness followed by hemifacial convulsion in one and the other had three nocturnal seizures in which she awoke and described flashing white colored spots, followed by deviation of the eyes and head and impaired consciousness (Table 1, patients 20 and 21). In patient 20 the seizure symptomatology was the same as in children with CEOP and in patient 21 it was the same as in children with BNCOE. In all patients the background activity in the EEG was normal. The occipital paroxysms were suppressed or strikingly reduced by opening the eyes (Fig. 1). This feature was prominent in patients with CEOP compared to those having BNCOE. The paroxysms were not influenced by hyperventilation or photic stimulation. In patients with tonic deviation of the eyes the spikes always occurred in the contralateral occipital region. In patients with this ictal phenomenon and bilateral independent occipital spikes in the EEG, the spikes were frequent and high in amplitude in the contralateral region. In addition to the occipital spikes, independent centro-temporal spikes were recorded in three cases (patients 4, 6 and 16) and generalized spike-wave discharges were recorded in another three cases (patients 3, 7 and 14).
4. Discussion According to the International Classification of the Epilepsies, Epileptic Syndromes and Related Seizure Disorders, the seizures in CEOP usually start with visual symptoms and are often followed by a hemiclonic seizure or automatisms [1]. BNCOE characterized with nocturnal seizures and occipital spikes or spike-wave complexes in the EEG is not included by the Commission [1,2]. In our study, nine patients were classified as BNCOE. In terms of seizure symptomatology, BNCOE is characterized by tonic deviation of the eyes and head followed by vomiting [2]. This phenomenon was observed in five patients. It must be stressed that in our study all children with this ictal symptom (tonic deviation of the eyes) awoke from sleep and described additional visual symptoms. This observation has not been emphasized in previous studies. One explanation is that the onset of the seizure was missed. In these patients the ictal symptomatology was restricted to visual symptoms and tonic deviation of the eyes without impairment of consciousness when the seizure lasted only a few minutes. However, the prolonged seizures were associated with loss of consciousness. In this group, the seizure frequency was low, the age of onset was usually under 8 years of age and the prognosis was excellent as described in previous reports [8,9]. Three patients were followed without any
Fig. 1. Typical EEG showing rhythmic occipital spike-wavedischarges suppressedby eye opening. Top, EEG recorded when the eyes were open; middle, EEG recordedwhen the eyes were closed; bottom,EEG recordedwhen the eyes were open again. Arrowsindicate the onset of opening or closingof the eyes.
A.D. Yal~zn et al. / Brain & Development 19 (1997) 408-413
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............!----.:~---~-
:
..........:~ ...................... 4-...: ..................... t~--:
411
412
A.D. Yalgm et al. / Brain & Development 19 (1997) 408-413
antiepileptic drug treatment and two patients remained seizure-free for more than 1 year after discontinuation of antiepileptic drugs. In this group only one patient had rare seizures under antiepileptic drug treatment. Three of our patients had difficulties at school; according to their teachers their performance at school was poor compared to that of their classmates. One of these patients, a 12-yearold boy, required additional private lessons. The diurnal seizures in our series always began with visual symptoms followed by impaired or loss of consciousness during the attack, but were not accompanied by generalized convulsion. We claim that sleep is a predisposing factor for secondary generalization. Among the visual symptoms the most common was partial or complete visual loss in the entire or partial visual field. Some authors draw attention to the fact that the seizures in CEOP are frequent and not always easy to control [10,11]. In contrast, other reports suggest that the seizures in CEOP and BNCOE are infrequent and easily controlled [1,9,12]. In our group the frequency of seizure was high compared to the first group. In two patients with ictal visual symptoms (patients 20 and 21), the repeated EEG recordings were normal. These children belong to the incomplete syndrome, in which either the ictal visual symptoms or the interictal EEG abnormalities are present [12]. The EEG in both syndromes typically shows spikes or sharp waves in the occipital and posterotemporal regions. The spikes usually appear rhythmically at a frequency of 13 Hz in bursts or trains. The paroxysms are characteristically suppressed or strikingly reduced by eye opening [3,9,10]. In our series these EEG features were recorded more than once in all patients except two. In all patients with tonic deviation of the eyes the spikes appeared in the contralateral occipital region. They were frequent and high in amplitude in the contralateral region if they appeared bilaterally. In three cases, in addition to the occipital spikes, independent centro-temporal spikes were observed, while in three different cases, generalized spike-wave discharges were recorded. In one study, over a third of the cases had generalized, bilaterally synchronous spike-waves or multiple spike-wave discharges or centrotemporal spikes [12]. Occipital spikes, suppressed by eye opening, are not pathognomonic for CEOP and BNCOE. This EEG pattern has also been observed in patients with basiler artery migraine with seizures, either focal or generalized [4,5]. It can also be observed in those patients having status epilepticus in addition to basilar artery migraine or those with migraine alone [5,6]. The same EEG abnormality has also been reported in children who have no paroxysmal phenomena [6]. Also in cases with symptomatic epilepsy, for example in patients with bilateral occipital corticosubcortical calcifications without any sign of phakomatosis, the same EEG pattern can be found [7]. In some reports the clinical manifestations and prognosis of patients, who were selected only because of their occipital paroxysms in EEG, were variable [6,8,11]. In the study
of Talwar et al. [6] which includes 30 patients with occipital-posterotemporal spike-wave paroxysms suppressed by opening of the eyes, only eight patients could be classified as CEOP. Newton and Aicardi [11] reported 16 patients with the same EEG abnormality and emphasized poor response to the treatment and the high frequency of learning difficulties in these children. Among seven patients with CT examination, three showed abnormalities. In a more recent study including 31 patients with occipital spike-sharp waves with suppression of the discharges with eye opening, six patients had CEOP and 17 had BNCOE. The authors concluded that this EEG abnormality was not specific for a single epileptic syndrome [8]. We claim that in the diagnosis of CEOP and BNCOE the seizure symptomatology is important. Awakening from sleep with tonic deviation of the eyes and visual symptoms followed by loss of consciousness is the typical seizure pattern of BNCOE. In CEOP generalized convulsion is not expected. Learning difficulties can be observed frequently in children with BNCOE compared to patients with CEOP which does not contradict the diagnosis. The diagnosis of CEOP and BNCOE must be supported by the seizure symptomatology even if the EEG is typical. The combination of occipital spikes with centro-temporal spikes or generalized spike-wave discharges cannot be helpful in classifying these two types of clinical syndromes, but such a combination suggests the idiopathic nature of these epilepsies. Finally, we believe that BNCOE is an idiopathic syndrome distinct from CEOP with lower seizure frequency, lower onset of seizure, unique seizure symptomatology and excellent prognosis. In patients with mixed symptomatology of both CEOP and BNCOE, the onset of seizures was after 8 years of age and the seizure frequency was high like CEOP. In our opinion, these patients belong to a subgroup of CEOP.
References [1] Commissionon Classificationand Terminologyof the International
[2] [3] [4] [5] [6] [7]
League AgainstEpilepsyProposalfor classificationof epilepsies and epileptic syndromes.Epilepsia 1985; 26: 268-278. PanayiotopoulosCP. Benign nocturnal childhood occipital epilepsy: a new syndromewith nocturnal seizures,tonic deviationof the eyes, and vomiting. Child Neurol 1989; 4: 43-49. Holmes GL. Benign focal epilepsies of childhood. Epilepsia 1993; 34: $49-$61. CamfieldPR, MetrakosK, AndermannF. Basiler migraine, seizures and severe epileptiformEEG abnormalities. Neurology 1978; 28: 584-588. PanayiotopoulosCP. Basilermigraine?Seizures, and severeepileptic EEG abnormalities.Neurology 1980; 30:1122-I 125. Talwar D, Rask CA, Torres F. Clinical manifestations in children with occipital spike-waveparoxysms.Epilepsia 1992; 33: 667-674. Gobbi G, Sorrenti G, Santucci M, Giovanardi RP, Ambrosetto P, Michelucci R et al. Epilepsywith bilateral occipital calcification: a benign onset with progressive severity. Neurology 1988; 38: 913920.
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[8] Maher J, Ronen GM, Ogunyemi AO, Goulden KJ. Occipital paroxysmal discharges suppressed by eye opening: variability in clinical and seizure manifestations in childhood. Epilepsia 1995; 36: 52-57. [9] Panayiotopoulos CP. Benign childhood epilepsy with occipital paroxysms: a 15-year prospective study. Ann Neurol 1989; 26: 51-56. [10] Gaustaut H. Benign epilepsy of childhood with occipital paroxysms. In: Roger J, Davet C, Bureau M, Dreifuss FE, Wolf P, editors. Epileptic Syndromes in InfaJacy, Childhood and Adolescence. London: Libbey Eurotext, 1992: 201-2t7.
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[11] Newton R, Aicardi J. Clinical findings in children with occipital complexes suppressed by eye opening. Neurology 1983; 33: 15261529. [12] Gaustaut H, Zifkin BG. Benign epilepsy of childhood with occipital spike and wave complexes. In: Andermann F, Lugaresi E, editors. Migraine and Epilepsy. Boston, MA: Butterworth, 1987: 47-82.
Brain & Development 19 (1997) 408-413
Original article
Childhood occipital epilepsy: seizure manifestations and electroencephalographic features A. Destina Yalqln*, Asuman
Kaymaz, Hulki Forta
Department of Neurology, ~i~li Etfal Education Hospital, ~i¢li, istanbul, Turkey Received 3 December 1996; revised version received 3 July 1997; accepted 10 July 1997
Abstract Childhood epilepsy with occipital paroxysms (CEOP) is an idiopathic localization-related epilepsy. A typical seizure in CEOP begins with visual symptoms, followed by hemiclonic seizures, complex partial seizures or generalized tonic-clonic seizures. Benign nocturnal childhood occipital epilepsy (BNCOE), characterized by nocturnal seizures with tonic deviation of the eyes followed by vomiting, has the same electroencephalographic features as CEOP. In this study, we report the seizure symptoms and electroencephalographic features of 21 cases with CEOP or BNCOE. Out of these patients, nine had BNCOE, six had CEOP, four had CEOP and BNCOE and the remaining two belonged to the incomplete syndrome because of no paroxysmal discharges in EEG. When the patients with BNCOE awoke from sleep, they had tonic deviation of the eyes and could describe visual symptoms. Patients with CEOP had seizures beginning with visual symptoms followed by loss of consciousness but no generalized convulsions. In three cases, in addition to the occipital spikes, independent centrotemporal spikes were recorded and in another three cases generalized spike-wave discharges were recorded. Such a combination suggests the idiopathic nature of these epilepsies. We concluded that in the diagnosis of CEOP and BNCOE, the seizure symptomatology is important even if the EEG can be considered normal. © 1997 Elsevier Science B.V. Keywords: Childhood epilepsy with occipital paroxysms; Benign nocturnal childhood occipital epilepsy; Seizure symptomatology
1. Introduction Childhood epilepsy with occipital paroxysms (CEOP) is established as an idiopathic localization-related epilepsy in the International Classification of the Epilepsies, Epileptic Syndromes and Related Seizure Disorders. A typical seizure in CEOP begins with visual symptoms, followed by hemiclonic seizures, complex partial seizures and generalized tonic-clonic seizures [1]. On the other hand, benign nocturnal childhood occipital epilepsy (BNCOE), characterized by nocturnal seizures with tonic deviation of the eyes followed by vomiting, has the same electroencephalographic features as CEOP [2]. The EEG typically shows spikes or sharp waves in the occipital and posterotemporal regions. The spikes usually appear rhythmically at a frequency of 1-3 *Corresponding author. Selquklar Sokak, 51/14, Akatlar, 80630, |stanbul, Turkey. TeL/fax: +90 212 2793124.
0387-7604/97/$17.00 © 1997 Elsevier Science B.V. All rights reserved PII S0387-7604(97)00054-5
Hz in bursts or trains. The paroxysms are characteristically suppressed or strikingly reduced by eye opening [3]. This EEG pattern has also been observed in patients with basilar artery migraine and in children without paroxysmal phenomena [4-6]. The same EEG pattern can be found in cases with symptomatic epilepsy, for example in patients with bilateral occipital corticosubcortical calcifications without any sign of phakomatosis [7]. In this study, we report the seizure symptoms and electroencephalographic features of 21 cases with CEOP or BNCOE.
2. Patients and methods In this study, patients who had seizures with occipital spikes in EEG and who were followed by the Epilepsy Outpatient Clinic of ~i~li Etfal Education Hospital, Istanbul were screened. Nineteen patients who fulfilled the following
A.D. Yal~m et al. /Brain & Development 19 (1997) 408-413
409
Table 1 Seizure symptomatology and electroencephalographic features of the patients Patient/sex/age (years) at last review
Age at firsl seizure (years)
Age at last seizure (years)
Seizure number (nocturnal/diurnal)
Seizure symptomatology
EEG
1/M/6 2/M/10 3/M/5.5 4/M/7 5/F/7 6/M/12 7/F/6 8/M/10 9/M/11 10/F/15 ll/M/14 12/M/17 13/M/23 14/F/7 15/F/14 16/M/10 17/M/11 18/M/14 19/F/17 20/F/13 21/F/15
5 3 2.5 3 5 7 5 6 7 10 12 5 11 1.5 13 9 9 11 16 12 12
5 3 3 6 5 8 5 6.5 7.5 13 14 17 23 5 13 9.5 9 14 17 12 15
2N 3N 3N Many N 2N 2N 3N 3N 2N Many D 9D Many D Many D 3D 4D 1N/3D 1N/3D 3N/many D 2N/2D 4D 3N
AS, ED, B, LOC, H GC AS, ED, BV, LOC, V HC AS, ED, VH, LOC, V GC GC AS, ED, B, V, LOC AS, ED, VH, LOC BV, ED, LOC, HFC B, ED, LOC, V, H BV, ED, LOC B, VH, ED, V, LOC, H VH, ED, V, H, LOC BV, ED, V, LOC, HFC, H N: AS, ED, BV, LOC; D: PLOC, A N: GC; D: VH, ED, LOC N: AS, BV, VH, ED, LOC; D: BV, VH, ED, LOC N: GC; D: VH, ED, LOC B, ED, LOC, V, HFC, H AS, VH, ED, LOC, V
L Oc Bil Oc R Oc, Gen L Oc, L CT Bil Oc Bil Oc, R CT L Oc, Gen R Oc L Oc Bil Oc R Oc R Oc R Oc Bil Oc, Gen L Oc L Oc, R CT L Oc L Oc L Oc nl nl
AS, awakening from sleep; ED, deviation of the eyes; B, blindness; LOC, loss of consciousness; H, headache; GC, generalized convulsion; BV, blurred vision; V, vomiting; VH, visual hallucination; HFC, hemifacial convulsion; PLOC, prolonged loss of consciousness; A, automatism; L Oc, left occipital spike-wave; R Oc, right occipital spike-wave; Bil Oc, bilateral occipital spike-wave; L CT, left centrotemporal spike; R CT, right centrotemporal spike; Gen, generalized spike-wave; nl, normal.
criteria were included in the study: (1) diurnal or nocturnal seizures associated with occipital spikes or spike-waves in the EEG, suppressed by eye opening; (2) onset of seizures before 17 years of age; and (3) normal computed tomo-
graphic (CT) brain scan or magnetic resonance imaging (MRI). The following patients were excluded: (1) patients with occipital spikes or spike-waves who had myoclonic, photo-
Table 2 Neurological findings, response to antiepileptic drug treatment and family history of the patients Patient
Neurologic findings
Antiepileptic drugs
1
PSP Normal PSP Normal Normal PSP Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal
No CBZ CBZ CBZ CBZ CBZ No No PB CBZ PT VA PT CBZ CBZ PT CBZ CBZ CBZ PT CBZ
2 3
4 5 6
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Seizure frequency under treatment
Rare -
Rare Rare Rare Rare Rare Rare Rare -
Years without medication
Family history of seizures or febrile convulsions
-
Yes Yes No No Yes No Yes Yes No No No No No No No No No Yes (FC) No Yes No
3 1 -
PSP, poor school performance; CBZ, carbamazepine; PB, phenobarbital; PT, phenytoin; VA, valproic acid; FC, febrile convulsion.
410
A.D. Yal¢m et al. / Brain & Development 19 (1997) 408-413
sensitive, absence or Rolandic epilepsy; (2) patients with occipital paroxysms and febrile convulsion; and (3) patients with symptomatic epilepsy and occipital spikes. In addition to 19 patients who fulfilled the above criteria, two patients with typical ictal visual symptoms but normal EEG findings were included. The ictal symptomatology was assessed from the descriptions of the patients and their parents. In addition to their regular visits every 2 months, the patients were asked to visit our Epilepsy Outpatient Clinic as soon as possible after each seizure to report the details of the seizure symptoms.
3. Results Nine patients had only nocturnal seizures and were classified as BNCOE (Table 1, patients 1-9). In three patients the seizures were described as tonic-clonic convulsion and in one as hemiconvulsion. These patients were unconscious during the seizure. Tonic deviation of the eyes was observed in five children. All these patients awoke from sleep and could describe visual symptoms; three reported blindness or blurred vision and the rest colorful moving spots. In these patients if the seizure lasted a few minutes, consciousness was not impaired and the patients were able to speak with their parents. However, when seizures were prolonged, deviation of the eyes continued and the patient became unconscious. Vomiting was observed in three patients. Three of our patients had difficulties at school; according to their teachers their performance at school was poor compared to that of their classmates. One of these patients, a 12year-old boy, required additional private lessons. The seizure frequency was low and the seizures responded well to treatment. Only one patient had rare seizures under treatment, while the others with or without treatment stayed seizure-free (Table 2). Six patients had CEOP (Table 1, patients 10-15). These patients had only diurnal seizures which always began with visual symptoms. These symptoms were described as partial or complete blurred vision of the entire or partial visual field in four patients and as moving or flashing colored spots or circles in one patient. One patient described both ictal visual symptoms. All these patients also had tonic deviation of the eyes. None of these patients had convulsive phenomena although consciousness was impaired or lost during the seizures in all cases. Vomiting was observed in four patients. In all patients mental development was normal. The seizure frequency was variable, but high compared to patients who had only nocturnal seizures (Table 1). Four patients had diurnal as well as nocturnal seizures and were classified as having CEOP and BNCOE (Table 1, patients 16-19). In one child complex partial seizures with automatism and prolonged unconsciousness were
noted three times. Although all of the EEGs recorded were normal, two patients had seizures with ictal visual symptoms; one had four diurnal seizures with blindness followed by hemifacial convulsion in one and the other had three nocturnal seizures in which she awoke and described flashing white colored spots, followed by deviation of the eyes and head and impaired consciousness (Table 1, patients 20 and 21). In patient 20 the seizure symptomatology was the same as in children with CEOP and in patient 21 it was the same as in children with BNCOE. In all patients the background activity in the EEG was normal. The occipital paroxysms were suppressed or strikingly reduced by opening the eyes (Fig. 1). This feature was prominent in patients with CEOP compared to those having BNCOE. The paroxysms were not influenced by hyperventilation or photic stimulation. In patients with tonic deviation of the eyes the spikes always occurred in the contralateral occipital region. In patients with this ictal phenomenon and bilateral independent occipital spikes in the EEG, the spikes were frequent and high in amplitude in the contralateral region. In addition to the occipital spikes, independent centro-temporal spikes were recorded in three cases (patients 4, 6 and 16) and generalized spike-wave discharges were recorded in another three cases (patients 3, 7 and 14).
4. Discussion According to the International Classification of the Epilepsies, Epileptic Syndromes and Related Seizure Disorders, the seizures in CEOP usually start with visual symptoms and are often followed by a hemiclonic seizure or automatisms [1]. BNCOE characterized with nocturnal seizures and occipital spikes or spike-wave complexes in the EEG is not included by the Commission [1,2]. In our study, nine patients were classified as BNCOE. In terms of seizure symptomatology, BNCOE is characterized by tonic deviation of the eyes and head followed by vomiting [2]. This phenomenon was observed in five patients. It must be stressed that in our study all children with this ictal symptom (tonic deviation of the eyes) awoke from sleep and described additional visual symptoms. This observation has not been emphasized in previous studies. One explanation is that the onset of the seizure was missed. In these patients the ictal symptomatology was restricted to visual symptoms and tonic deviation of the eyes without impairment of consciousness when the seizure lasted only a few minutes. However, the prolonged seizures were associated with loss of consciousness. In this group, the seizure frequency was low, the age of onset was usually under 8 years of age and the prognosis was excellent as described in previous reports [8,9]. Three patients were followed without any
Fig. 1. Typical EEG showing rhythmic occipital spike-wavedischarges suppressedby eye opening. Top, EEG recorded when the eyes were open; middle, EEG recordedwhen the eyes were closed; bottom,EEG recordedwhen the eyes were open again. Arrowsindicate the onset of opening or closingof the eyes.
A.D. Yal~zn et al. / Brain & Development 19 (1997) 408-413
L,..~I ...............'~ .............~-t:
............!----.:~---~-
:
..........:~ ...................... 4-...: ..................... t~--:
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antiepileptic drug treatment and two patients remained seizure-free for more than 1 year after discontinuation of antiepileptic drugs. In this group only one patient had rare seizures under antiepileptic drug treatment. Three of our patients had difficulties at school; according to their teachers their performance at school was poor compared to that of their classmates. One of these patients, a 12-yearold boy, required additional private lessons. The diurnal seizures in our series always began with visual symptoms followed by impaired or loss of consciousness during the attack, but were not accompanied by generalized convulsion. We claim that sleep is a predisposing factor for secondary generalization. Among the visual symptoms the most common was partial or complete visual loss in the entire or partial visual field. Some authors draw attention to the fact that the seizures in CEOP are frequent and not always easy to control [10,11]. In contrast, other reports suggest that the seizures in CEOP and BNCOE are infrequent and easily controlled [1,9,12]. In our group the frequency of seizure was high compared to the first group. In two patients with ictal visual symptoms (patients 20 and 21), the repeated EEG recordings were normal. These children belong to the incomplete syndrome, in which either the ictal visual symptoms or the interictal EEG abnormalities are present [12]. The EEG in both syndromes typically shows spikes or sharp waves in the occipital and posterotemporal regions. The spikes usually appear rhythmically at a frequency of 13 Hz in bursts or trains. The paroxysms are characteristically suppressed or strikingly reduced by eye opening [3,9,10]. In our series these EEG features were recorded more than once in all patients except two. In all patients with tonic deviation of the eyes the spikes appeared in the contralateral occipital region. They were frequent and high in amplitude in the contralateral region if they appeared bilaterally. In three cases, in addition to the occipital spikes, independent centro-temporal spikes were observed, while in three different cases, generalized spike-wave discharges were recorded. In one study, over a third of the cases had generalized, bilaterally synchronous spike-waves or multiple spike-wave discharges or centrotemporal spikes [12]. Occipital spikes, suppressed by eye opening, are not pathognomonic for CEOP and BNCOE. This EEG pattern has also been observed in patients with basiler artery migraine with seizures, either focal or generalized [4,5]. It can also be observed in those patients having status epilepticus in addition to basilar artery migraine or those with migraine alone [5,6]. The same EEG abnormality has also been reported in children who have no paroxysmal phenomena [6]. Also in cases with symptomatic epilepsy, for example in patients with bilateral occipital corticosubcortical calcifications without any sign of phakomatosis, the same EEG pattern can be found [7]. In some reports the clinical manifestations and prognosis of patients, who were selected only because of their occipital paroxysms in EEG, were variable [6,8,11]. In the study
of Talwar et al. [6] which includes 30 patients with occipital-posterotemporal spike-wave paroxysms suppressed by opening of the eyes, only eight patients could be classified as CEOP. Newton and Aicardi [11] reported 16 patients with the same EEG abnormality and emphasized poor response to the treatment and the high frequency of learning difficulties in these children. Among seven patients with CT examination, three showed abnormalities. In a more recent study including 31 patients with occipital spike-sharp waves with suppression of the discharges with eye opening, six patients had CEOP and 17 had BNCOE. The authors concluded that this EEG abnormality was not specific for a single epileptic syndrome [8]. We claim that in the diagnosis of CEOP and BNCOE the seizure symptomatology is important. Awakening from sleep with tonic deviation of the eyes and visual symptoms followed by loss of consciousness is the typical seizure pattern of BNCOE. In CEOP generalized convulsion is not expected. Learning difficulties can be observed frequently in children with BNCOE compared to patients with CEOP which does not contradict the diagnosis. The diagnosis of CEOP and BNCOE must be supported by the seizure symptomatology even if the EEG is typical. The combination of occipital spikes with centro-temporal spikes or generalized spike-wave discharges cannot be helpful in classifying these two types of clinical syndromes, but such a combination suggests the idiopathic nature of these epilepsies. Finally, we believe that BNCOE is an idiopathic syndrome distinct from CEOP with lower seizure frequency, lower onset of seizure, unique seizure symptomatology and excellent prognosis. In patients with mixed symptomatology of both CEOP and BNCOE, the onset of seizures was after 8 years of age and the seizure frequency was high like CEOP. In our opinion, these patients belong to a subgroup of CEOP.
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