Early-Onset Benign Occipital Seizure Susceptibility Syndrome

Summary: Purpose: Childhood epilepsy with occipital paroxysms (CEOP) is characterised by ictal visual hallucinations and occipital epileptiform activity on interictal EEG. A variant has been described with nonvisual symptoms including tonic head and eye deviation, vomiting, and episodes of partial status epilepticus. We fully documented the electroclinical features of such patients to determine whether classification separate from CEOP is justified.
Methods: This was a multicentre study with participating investigators submitting details of patients with idiopathic occipital seizures characterised by ictal head or eye deviation and vomiting.
Results: One hundred thirteen patients were recruited. Seizures began in early childhood (mean, 4.6 years) and occurred infrequently (mean total seizures, 3); 30% of patients had only a single seizure. Two thirds of seizures were nocturnal. Ictal eye deviation occurred in 79%, vomiting in 70%, and head deviation in 35%. Seizures were predominantly complex partial in type. Partial status epilepticus occurred in 44% of patients. Seventy-four percent of patients had occipital interictal EEG epileptiform activity, predominantly right sided, with fixation-off sensitivity. Extraoccipital EEG abnormalities occurred in 35% of patients. Prognosis was excellent: the mean duration of active seizures was 1 year.
Conclusions: Although the two groups shared identical EEG features, the distinct clinical symptoms probably justify separate classification. Early-onset benign occipital seizure syndrome (EBOSS) is suggested as an appropriate name for the variant group.     

Rolandic Epilepsy: An Incidence Study in Iceland

Summary: Purpose: We wished to determine incidence, clinical features, and prognosis of benign rolandic seizures (BRS) and benign rolandic epilepsy (BRE) in a total population.
Methods: Cases were ascertained through review of all EEG records, and diagnosis was verified by review of medical records. Follow-up information regarding seizures and treatment was obtained from parents and treating physicians.
Results: In the Icelandic population aged 3–15 years, the incidence of BRS is 6.2 and BRE 4.7 in 100,000. Five years after onset 95% were seizure-free. At last follow-up, all were seizure free and had not been treated with antiepileptic drugs (AEDs) for at least 1 year.
Conclusions: Our study demonstrates that BRS is a common entity in children. The prognosis is excellent and treatment is not necessary in all cases. It is important to identify BREBRS correctly and distinguish it from other types of epilepsy.     

Benign Familial Neonatal Convulsions Followed by Benign Epilepsy with Centrotemporal Spikes in Two Siblings

Summary: Purpose: To report on sibling cases with benign familial neonatal convulsions (BFNC) followed by benign epilepsy with centrotemporal spikes (BECT).
Methods: Case histories and EEGs were obtained for the two siblings with neonatal and subsequent epileptic seizures in one pedigree with BFNC.
Results: The family included six affected cases of BFNC in two generations: the proband, the proband's mother and two sisters, and the proband's maternal uncle and his daughter. The proband developed a generalized tonic convulsion 2 days after birth with no apparent cause and normal interictal EEG, and experienced a total of 18 episodes of tonic or clonic seizures or both by age 9 months. In the follow-up course, an EEG recording showed rolandic discharges at 2 years, and a sylvian seizure occurred at 4 years during sleep. On carbamazepine therapy, the last seizure was recorded at 9 years after a total of 11 episodes of sylvian seizures, with normal EEGs after 12 years. The proband's sister experienced nine episodes of brief tonic seizures between 7 and 9 days after birth, and also developed eight episodes of sylvian seizures from 4 to 7 years, with rolandic discharges on EEG until age 9 years. All of the family members had normal psychomotor development, with no neurologic sequelae.
Conclusions: This report of BFNC followed by BECT in sibling cases is significant in view of the genetic analysis and the classification of epilepsies and epileptic syndromes.     

Clinical and EEG characteristics of benign rolandic epilepsy in Chinese patients

We retrospectively evaluated the clinical and electroencephalogram (EEG) characteristics of benign rolandic epilepsy (BRE) in Chinese children. Two hundred and seventy-six patients with BRE were enrolled in this study. All patients had their first seizure between the ages of 3 and 12 years. 39.5% (109 cases) of patients ceased to have further BRE seizures by the age of 6 years, 93.1% (257 cases) recovered by the age of 12 years and 96.7% (267 cases) recovered by the age of 18 years. Two hundred and twenty-seven patients suffered only simple partial seizures, whereas 49 patients suffered generalized seizures from onset of BRE. The EEG scans of 239 patients showed repetitive diphasic spikes or sharp waves with high amplitude, which were most dominant in the central or centrotemporal areas. The spikes were confined to one hemisphere in 180 patients and occurred bilaterally in 59 patients. Ninety-eight patients were treated with antiepileptic drugs (AEDs): carbamazepine (CBZ) or valproate (VPA). The study showed that, in Chinese children, BRE is remarkably characteristic in its clinical and EEG presentation. Although BRE is usually benign in terms of ease of control with AEDs and spontaneous seizure remission, for those patients with a high frequency of seizures, AEDs should be prescribed positively.     

Panayiotopoulos-type benign childhood occipital epilepsy: a prospective study

OBJECTIVE: To characterize the clinical and EEG features of the syndrome of benign childhood partial seizures with ictal vomiting and EEG occipital spikes (Panayiotopoulos syndrome [PS]). METHODS: Prospective study of children with normal general and neurologic examinations who had seizures with ictal vomiting and EEG with occipital spikes. RESULTS: From February 1990 to 1997, the authors found 66 patients with PS and 145 children with benign childhood epilepsy with centrotemporal spikes. Peak age at onset of PS was 5 years. Ictal deviation of the eyes and progression to generalized seizures were common. One-third had partial status epilepticus. During sleep, all had seizures. While awake, one-third also had seizures. Five children with PS had concurrent symptoms of rolandic epilepsy and another five developed rolandic seizures after remission of PS. Prognosis was excellent: one-third had a single seizure, one-half had two to five seizures, and only 4.5% had frequent seizures. CONCLUSIONS: Panayiotopoulos-type benign childhood occipital epilepsy is less common than benign childhood epilepsy with centrotemporal spikes but is well defined and recognizable by clinical and EEG features.     

Idiopathic Photosensitive Occipital Lobe Epilepsy

Summary: We studied 10 neurologically normal patients (8 females, 2 males) aged 8–30 years (mean 17 years) who had recurrent episodes of visually induced occipital seizures. Television and computer screens were the main triggers. Seizure onset occurred between the ages of 5 and 17 years (mean 11 years). All seizures were stimulus related and began with elementary visual symptoms, followed in most patients by a slow clustering of cephalicpain, epigastric discomfort, and vomiting, with either normal or only mildly impaired responsiveness. EEG fea-tures included normal background activity, occipital spikes and waves, and a photoparoxysmal response which could be occipital, generalized, or both. Four pa-tients also showed spontaneous generalized epileptiform abnormalities, and 3 had rolandic spikes. An Oz electrode was critical in identifying epileptiform activity in some patients. Complete seizure control was achieved in most patients with monotherapy, although occasional stimulus-related seizures occurred in 3 patients who showed a wider range of photosensitivity. These patients have an idiopathic localization-related epilepsy with age-related onset and specific mode of precipitation. Although this type of epilepsy has been reported previously, it has remained underrecognized, probably because it is difficult to differentiate clinically from migraine or from nonreflex childhood idiopathic occipital epilepsy.     

The Absence of Interictal Spikes with Documented Seizures Suggests Extratemporal Epilepsy

PURPOSE: To determine the demographic and clinical characteristics of patients who have documented epileptic seizures on long-term video-EEG monitoring who do not have interictal spikes. METHODS: The records of 1,223 monitoring studies from 919 patients who underwent noninvasive long-term video-EEG monitoring were reviewed. In 28 patients (3.0% of monitored patients, 4.4% of patients with electrographic evidence of epilepsy), no interictal spikes were found despite the occurrence of at least one recorded electrographic seizure. The demographic, medical, neuropsychological, and EEG data of these patients were compared with those of 28 matched control patients with documented interictal spikes. RESULTS: Extratemporal seizures were significantly more frequent in the patients with at least one recorded epileptic seizure but without interictal spikes compared with patients with epileptic seizures and interictal spikes (p = 0.031). The only other significant difference between the groups (p = 0.016) was a later age at seizure onset (18.3 vs. 10.7 years) for the patients without interictal spikes. Age at evaluation, gender, handedness, clinical seizure type, family history of epilepsy, history of febrile seizures, neuropsychological testing, and neurologic and psychiatric history did not differ between the two groups. CONCLUSIONS: In patients with documented epilepsy without interictal spikes on EEG monitoring, the possibility of an extratemporal focus should be considered.     

Adult‐onset photosensitivity: clinical significance and epilepsy syndromes including idiopathic (possibly genetic) photosensitive occipital epilepsy

To evaluate the clinical associations of adult‐onset photosensitivity, we studied the clinical and EEG data of patients who were referred due to a possible first seizure and who had a photoparoxysmal response on their EEG. Patients with clinical evidence of photosensitivity before the age of 20 were excluded. Of a total of 30 patients, four had acute symptomatic seizures, two had vasovagal syncope, and 24 were diagnosed with epilepsy. Nine of the 24 patients had idiopathic (genetic) generalized epilepsies and predominantly generalized photoparoxysmal response, but also rare photically‐induced seizures, while 15 had exclusively, or almost exclusively, reflex photically‐induced occipital seizures with frequent secondary generalization and posterior photoparoxysmal response. Other important differences included a significantly older age at seizure onset and paucity of spontaneous interictal epileptic discharges in patients with photically‐induced occipital seizures; only a quarter of these had occasional occipital spikes, in contrast to the idiopathic (genetic) generalized epilepsy patients with typically generalized epileptic discharges. On the other hand, both groups shared a positive family history of epilepsy, common seizure threshold modulators (such as tiredness and sleep deprivation), normal neurological examination and MRI, a generally benign course, and good response to valproic acid. We demonstrated that photosensitivity can first occur in adult life and manifest, either as idiopathic (possibly genetic) photosensitive occipital epilepsy with secondary generalization or as an EEG, and less often, a clinical/EEG feature of idiopathic (genetic) generalized epilepsies. Identification of idiopathic photosensitive occipital epilepsy fills a diagnostic gap in adult first‐seizure epileptology and is clinically important because of its good response to antiepileptic drug treatment and fair prognosis.     

Occipitotemporal Epilepsies: Evaluation of Selected Patients Requiring Depth Electrodes Studies and Rationale for Surgical Approaches

Summary: In 8 patients in whom it was uncertain whether they had occipital or temporal lobe (TL) epilepsy, clinical, scalp EEG, and radiologic features were correlated with the sites of seizure onset as determined by depth EEG. The 8 patients were selected from >40 with occipital epilepsy because they had (a) an aura considered to be of occipital lobe (OL) origin, (b) an occipital interictal epileptic focus, (c) an OL lesion, or (d) a combination of all of these. Scalp EEG and clinical patterns suggested temporal involvement in all, however. Extracranial EEG recordings were often misleading, showing multilobar interictal epileptic abnormalities, and seizure onset was of poor localizing value and did not clarify the problem sufficiently. Intracranial EEG recordings showed that seizure onset could be ordered along an Occipitotemporal gradient. Consistent OL seizure onset was observed in patients who had only elementary visual auras. Those who had inconsistent aura or no aura, suggesting OL origin, had onset of most attacks in the TL. All patients had a seizure spread pattern suggesting early TL involvement. To prevent visual field defect, surgical approaches included temporal resection when temporal seizure origin or spread was demonstrated; although occasionally this produced excellent results, it was of limited benefit in most patients, even when some seizures were proven to originate in TL structures. In patients with malignant epilepsy and in those with an occipital lesion, occipital resection should be considered.     

Benign Rolandic Epilepsy: High Central and Low Central Subgroups

Summary: The spikes in benign rolandic epilepsy (BRE) typically involve both the central and midtemporal regions as recorded on standard EEG montages, but the seizures are characterized by sensorimotor manifestations that are rarely referable to the temporal lobe. To study this apparent disparity, we evaluated the field distribution of interictal spikes in 33 BRE patients using closely spaced electrodes (AEEGS 1990) arranged over perisylvian cortex. None of the 33 patients showed maximum negativity in the midtemporal regions (T3/T4). Instead, maximum negativity was evident in the high central region (C3/C4) in 10 children (30.3%) and in the low central region (C5/C6) in 23 (69.7%). Hand involvement was significantly frequent (50%) in the high central group, and drooling with oromotor involvement was a distinctive symptom (65.2%) in the low central group. Our findings indicate that the spikes in patients with BRE are exclusively suprasylvian in origin and correlate with two electroclinical subgroups.     

What is the Relationship Between Arachnoid Cysts and Seizure Foci?

Summary: Purpose: Arachnoid cysts are sometimes encountered in MRIs performed for a variety of reasons. In patients with epilepsy, particularly those with refractory epilepsy, arachnoid cysts are often assumed to be related to their seizure focus. We conducted a study to investigate this putative relationship.
Methods: A retrospective study on the incidence of arachnoid cysts was performed in patients seen in our Epilepsy Clinic who had CT or MRI scans, interictal EEGs or ictal EEGS. Locations of seizure foci in these patients were defined from clinical and electrophysiologic data.
Results: Seventeen of 867 patients had arachnoid cysts. Twelve patients had temporal lobe cysts and only 3 of them had temporal lobe seizures. Four patients had frontal lobe cysts and only 1 had frontal lobe seizures ipsilateral to the cyst. One patient had a cerebellopontine angle cyst and frontal lobe seizures. Thus, clinical manifestations of seizures and EEG findings (interictal and/or ictal) indicated that the seizure focus was adjacent to the cysts in only 4 patients (23.5%).
Conclusions: Our findings suggest that arachnoid cysts are often an incidental finding in patients with epilepsy and do not necessarily reflect the location of the seizure focus.     

Early-Childhood Progressive Myoclonus Epilepsy Presenting as Partial Seizures in Dentatorubral-Pallidoluysian Atrophy

Summary: Purpose: We explored the characteristics of epileptic seizures of progressive myoclonus epilepsy (PME) in 2 brothers with dentatorubral-pallidoluysian atrophy (DRPLA).
Methods: We obtained the case history of the siblings and ictal and interictal EEGs. Postmortem examination or demonstration of elongated CAG repeat in the gene for DRPLA was used to confirm the diagnosis.
Results: Two Japanese siblings developed PME characterized by versive or himiclonic seizures with or without secondarily generalized tonic-clonic convulsions. The elder brother regressed mentally and exhibited increasing spasticity after age 1 year. Myoclonus and seizures developed at age 4 years. The younger brother had shown psychomotor retardation before age 4 years, when he began to deteriorate further neurologically as the elder brother had. He also developed myoclonus and seizures at that age. Seizures in both patients remained partial until their deaths at ages 19 and 15 years, respectively. Ictal EEG verified partial onset of seizure evolving to generalized tonic-clonic seizure (GTCS). Interictal EEGs showed multifocal paroxysmal discharges with little or no diffuse paroxysms. Postmortem examination or genetic study confirmed the diagnosis of DRPLA.
Conclusions: Seizures of patients with DRPLA may present as partial seizures in children with early-onset PME.     

Rolandic epilepsy: report of 53 cases]

The clinical and EEG features of 53 out-patients with benign partial epilepsy of childhood with rolandic spikes were studied. The age mean (years) of seizures onset was 5.5 +/- 3.2. Simple partial seizures with speech arrest were more frequent than other seizure types. In seven cases (13.2%) cognitive disabilities were present. In the left-side foci a expected correlation between the interictal EEG focus and clinical lateralization of seizure was observed; in the right-side foci, the right-side interictal focus was correlated with ipsilateral seizures.     

Epilepsy in fragile X syndrome

Epilepsy is reported to occur in 10 to 20% of individuals with fragile X syndrome (FXS). A frequent seizure/EEG pattern in FXS appears to resemble that of benign focal epilepsy of childhood (BFEC, benign rolandic epilepsy). To evaluate seizure frequency and type in a Chicago FXS cohort, data regarding potential seizure history were reviewed for 136 individuals with FXS (age range 2 to 51 years: 113 males and 23 females). Seizures occurred in 15 males (13.3%) and one female (4.8%): of these, 12 had partial seizures. EEG findings were available for 35 individuals (13 of 16 with seizures and 22 of 120 without seizures) and showed an epileptiform abnormality in 10 (77%) individuals with seizures and five (23%) individuals without seizures--the most common epileptiform pattern being centrotemporal spikes. Seizures were easily controlled in 14 of the 16 individuals with seizures. Many individuals, including all with centrotemporal spikes, had remission of seizures in childhood. The most common seizure syndrome resembled BFEC and this pattern had the best prognosis for epilepsy remission. Deficiency of FMRP (fragile X mental retardation protein) appears to lead to increased neuronal excitability and susceptibility to epilepsy, but particularly seems to facilitate mechanisms leading to the BFEC pattern.     

Tactile‐evoked Rolandic Discharges: A Benign Finding?

PURPOSE: This retrospective study was undertaken to determine if patients having tactile-evoked rolandic discharges were a more "benign" patient population than those with spontaneously occurring nontactile rolandic discharges and to determine whether the presence of tactile-evoked rolandic discharges was a marker for the future development of epilepsy, as previously reported. METHODS: During this 8-year study, 304 patients were seen with rolandic discharges. These patients all had tactile stimulation of their hands and/or feet. They formed two groups: patients with spontaneous rolandic discharges that could not be evoked by tactile stimulation (NT) and patients with spontaneous rolandic discharges that could be enhanced with tactile stimulation (TE). Over a 14-month period, every patient had tactile stimulation of both hands and both feet, resulting in a third group of patients having rolandic discharges seen only with tapping (TO). RESULTS: Tactile-enhanced discharges constituted 38.2% of all rolandic discharges. Patients with TE and TO discharges had a higher incidence of normal development and intelligence, normal neurologic examinations, and a lower incidence of seizures and focal or generalized background abnormalities on their EEGs. Only one patient with normal background and no coexisting epileptiform abnormalities had partial motor seizures with corresponding contralateral central discharges. Only two patients who had no seizures at the time of their first EEG subsequently went on to develop seizures. Neither fit the pattern of the seizure disorder described in the literature. CONCLUSIONS: It is hypothesized that tactile-evoked rolandic discharges are a benign, age-related phenomenon, which do not represent a marker for the future development of epilepsy and are not the interictal electrographic correlate to an already existing seizure disorder.     

Clinico-Electroencephalographical Study of Focal Epilepsy with Special Reference to "Benign Epilepsy of Children with Centro-Temporal EEG Foci" and Its Age Dependency

Childhood epilepsy with nocturnal seizure and rolandic (centro-temporal) discharge on EEG, had recently been noted by some French and other European authors. These types of epilepsy usually appeared in middle childhood and showed a favorable effect to anticonvulsant therapy. The pre sent investigation deals with analysis of seizures and of some characteristics of rolandic discharge, particularly with respect to the cerebral maturational process involved in the appearance of seizure discharge. The patients were selected out by the symptoms of epilepsy and features of EEG's, consisting of 20 children in total. Fifteen patients showed somatomotor attacks and five showed somatosensory as well as somatomotor attacks. As for the duration of seizure, those who had seizures before three and 10 years of age, had attacks for relatively short periods, whereas those who had attacks from four to nine years of age, usually had longer duration. The amplitude of “RD” remained lower than 50 μv up to three years of age, whereas it reached as high as 200 μv up to nine years, particularly during sleep, which became lower after the age of 10. It was concluded that there is an age dependency between the ages of four and nine.     

A magnetoencephalographic study of patients with Panayiotopoulos syndrome

Summary:  Purpose: Panayiotopoulos syndrome (PS) is a newly identified type of benign childhood epilepsy characterized by ictal vomiting and eye deviation. It is usually accompanied by occipital spike discharges; however, its classification as an early-onset benign childhood occipital epilepsy is controversial. To characterize this condition further, we examined the localization of equivalent current dipoles (ECDs) of spike discharges by magnetoencephalography (MEG) in patients with PS.
Methods: We studied 13 patients with a mean age at time of examination of 5 years (range, 3–14 years). MEG was measured by using a whole-head 204-channel neuromagnetometer with simultaneous EEG recordings. The estimated locations of ECDs of each peak of the spike discharges were overlaid on magnetic resonance images of the brain.
Results: Eleven (84.6%) patients showed clustered ECDs in the areas alongside the parietooccipital sulcus (eight of 13; 61.5%) and/or the calcarine sulcus (four of 13; 30.8%). Despite Fp-O synchronization of the spike discharges in the scalp EEG of five patients, no frontal locations of ECDs were found. All five (38.5%) boys with sylvian seizures, who also showed clustered ECDs in rolandic areas, had an earlier age at onset and higher seizure frequency than did other patients. ECD orientations were regular in all but one patient, who showed irregular and dispersed ECDs alongside bilateral calcarine sulci.
Conclusions: Our results demonstrate localized cortical hyperexcitability in the areas alongside major cortical sulci in PS and indicate that PS is closely related to benign childhood epilepsy with centrotemporal spikes.     

Benign childhood epileptic syndromes with occipital spikes: new classification proposed by the International League Against Epilepsy

In a recent proposal, the Commission on Classification and Terminology of the International League Against Epilepsy recognized early-onset childhood epilepsy with occipital spikes (Panayiotopoulos type), differentiating it from the only other type of childhood epilepsy with occipital spikes previously accepted: late-onset childhood epilepsy with occipital spikes (Gastaut type). The importance of this newly recognized syndrome of benign childhood partial seizures is that it is very common-only 2.4 times less frequent than benign rolandic epilepsy, and of equally excellent prognosis. It is characterized by a unique seizure type comprising a combination of autonomic and behavioral disturbances, vomiting, deviation of the eyes, and often with impairment of consciousness that can progress to convulsions. These commonly last for more than 3 minutes and in one quarter of cases for hours. One or more of these symptoms can predominate or be absent. Eyes can remain open without deviation, ictal vomiting might not occur, and autonomic and behavioral disturbances can predominate, particularly in the early stages of the ictus, and be missed in nocturnal seizures. Age at onset is 5 years, with a singular or a median of three seizures, which are predominantly nocturnal. Interictal electroencephalography (EEG) frequently shows occipital paroxysms or occipital spikes but one-fifth of the cases have only extraoccipital spikes on normal EEG. Treatment might not be needed. Panayiotopoulos syndrome, like rolandic epilepsy, needs recognition by the general pediatrician because of the invariably excellent prognosis and also because it can be misdiagnosed as an acute cerebral insult.     

Occipital Lobe Developmental Malformations and Epilepsy: Clinical Spectrum, Treatment, and Outcome

Summary: Purpose : Cortical developmental malformations (CDM) are increasingly recognized in association with epilepsy. We describe 10 patients (age range 14–35 years) with symptomatic occipital lobe epilepsy and CDM.
Methods : Neurologic, neuroophthalmologic and electro-physiologic studies were performed. Patients had MRI, SPECT, and in some cases intracranial EEG investigators.
Results : Mean age of seizure onset was 8 years. We noted strong correlations between the presence of visual auras, the scalp EEG pattern, and the subtype of underlying pathology. Magnetic resonance imaging (MRI) showed CDM in all patients, with polymicrogyria and focal dysplasia being the most frequent malformations. Despite the presence of occipital lobe structural malformations in all patients, visual field deficits were present in only 2. Those who underwent cortical resections were seizure–free or showed major improvement at a mean follow–up of 3.5 years.
Conclusions : Intracranial stimulation studies and the low frequency of pre- and postoperative deficits suggest that some degree of cortical visual reorganization may occur in patients with occipital lobe malformations. Occipital lobe CDM should be sought as a cause of symptomatic occipital lobe epilepsy even though they may become symptomatic after childhood.     

Ictal Scalp EEG in Unilateral Mesial Temporal Lobe Epilepsy

Summary: Purpose: We wished to determine the predictive significance of unilateral hippocampal atrophy and interictal spikes on localization of ictal scalp EEG changes and assess whether ictal EEG provides information that might change treatment or influence prognosis in patients with such characteristics of epilepsy.
Methods: We analyzed EEG seizure patterns in 118 seizures in 24 patients with unilateral mesial temporal lobe epilepsy (MTLE) defined by typical clinical seizure semiology, unilateral hippocampal atrophy on magnetic resonance imaging (MRI) and unitemporal spikes on interictal EEG. Two blinded electroencephalographers independently determined morphology, location, and time course of ictal EEG changes.
Results: Lateralization was possible in 88.4–92.0% of seizures and always corresponded to the side of the interictal spike focus and of hippocampal atrophy on MRI. Although only 30.4–33.9% of seizures were lateralized at onset, a later significant pattern emerged (12.6–13.3 s after EEG seizure onset) that allowed lateralization in 82.4–91.O% of seizures with non-lateralized onset. Interobserver reliability for lateralization was excellent, with a K-value of 0.85. In most patients, either all (79.2–83.3%) or >50% (8.3–16.7%) of seizures were lateralized. In only a small proportion of patients (4.2–8.3%) were 40% of seizures lateralized. In 1 patient, no seizure could be lateralized by 1 electroencephalographer. The results of ictal EEG recordings did not alter the surgical approach and did not correlate with surgical outcome.
Conclusions: We conclude that unilateral hippocampal atrophy on MRI and unitemporal interictal spikes can predict localization of ictal scalp EEG changes with a high degree of reliability and that ictal EEG provides no additional localizing information in this particular patient group.