Reflex occipital lobe epilepsy.

Photosensitivity is a typical feature of photosensitive epilepsy which is usually considered a form of idiopathic generalized epilepsy. Partial seizures featuring visual symptoms are rarely reported in photosensitive epilepsy. In this study, we describe 13 neurologically normal patients in whom daytime seizures were always induced by television and began with elementary visual hallucinations, followed frequently by vomiting, headache and then secondary generalization. Three patients additionally reported nocturnal seizures, which have not been described in previous studies. Two of these latter patients had generalized tonic-clonic seizures, the other always awoke from sleep and could describe typical visual hallucinations at the beginning of the seizure. EEG features included normal background activity and occipital spikes or spike-waves in all but two patients. Eight patients also showed generalized epileptiform activity during intermittent photic stimulation. Seizure frequency was low in all. Apart from two patients, who refused treatment, all patients received antiepileptic drugs. Only one patient continued to have rare seizures after treatment; in the others seizure control was achieved with monotherapy. We conclude that reflex occipital lobe epilepsy is an idiopathic form of the benign partial epilepsies, which may overlap with one another.     

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.     

Somatosensory evoked spikes and epileptic seizures: a study of 385 cases.

We examined 385 children whose EEG showed high voltage potentials evoked by taps applied to one or both feet or hands (SES). The relationship between characteristics of SES and the occurrence of epileptic seizures and the characterization of epileptic syndromes were studied. Ninety-one children (23.6%) had epilepsy, 42 (10.9%) had only febrile convulsions and 252 children had other complaints. Epilepsy occurred in a higher proportion of cases when: SES by foot tapping were multiphasic, with high amplitude or SES were obtained by hand stimulation and there was spontaneous epileptiform activity in the EEG. The following epileptic syndromes were diagnosed: benign childhood epilepsy with centrotemporal spikes in 21 cases, benign epilepsy of childhood with occipital paroxysms in 2, benign psychomotor epilepsy in 1, "partial idiopathic others" in 43, generalized idiopathic in 8, symptomatic epilepsies in 13 and undetermined in 3 cases. In most cases SES were observed in children without evidence of cerebral organic lesion, suggesting the existence of an age-related, functional mechanism. Some characteristics of SES and the occurrence of spontaneous epileptiform activity showed a positive association with epileptic seizures. SES occurred in different types of partial and generalized epilepsies of childhood but in nearly 50% of the cases with epilepsy, there was a benign condition involving mainly the parietal lobe with versive, unilateral and sleep-generalized seizures.     

Temporal intermittent rhythmic delta activity in electroencephalograms.

Temporal intermittent rhythmic delta activity (TIRDA) has been reported to be highly specific for diagnosing complex partial epilepsy. Of 12,198 electroencephalographic (EEG) recordings performed at the Mayo Clinic between May 1, 1990 and May 1, 1991, 33 records from 27 patients (18 women and nine men; mean age, 41.5 years; range, 13-82 years) showed TIRDA. Clinical seizures were diagnosed in all patients, and complex partial epilepsy was well documented in 23. In a control group of 100 patients without TIRDA and matched for age and sex, generalized seizures were diagnosed in 25 and partial seizures in 15. Differences between TIRDA and control groups were highly statistically significant. Focal temporal sharp waves or spikes occurred in 23 patients with EEG recordings that contained TIRDA; three of these patients also exhibited generalized atypical spike-and-wave discharges. Four patients had TIRDA but no other epileptiform activity, although earlier EEGs of three of these patients contained spikes or sharp waves. These findings confirm earlier work, and we conclude that TIRDA represents an important epileptogenic abnormality.     

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.     

Idiopathic childhood occipital epilepsies: clinical and electroencephalographic features in 63 children

We studied clinical-EEG features of 63 children, age range of 2-14 years, with occipital epileptiform activity in the EEG, with epileptic seizures and no evidences of brain damage. Age at onset was between 1-12 years. In 15 cases the seizures last for more than 30 min up to 6 h. Seizures occurred during sleep in 28 children. Autonomic symptoms were apparent in 25, head deviation in 24 and hemiconvulsion or generalization in 17 cases. Ten children reported visual symptoms. In 14 children the seizures were exclusively generalised convulsions. Spikes were observed in 27 cases and spike and slow-wave complex in 36. Discharges blocking by eyes opening were confirmed in 15 cases. Somatosensory evoked spikes by foot stimulation were observed in 9.5% cases. The cases were classified in the following idiopathic epileptic syndromes: early-onset occipital -- Panayiotopoulos-type (EOO), 32 cases; late-onset occipital -- Gastaut type (LOO), 8; rolandic epilepsy in 7. CONCLUSION: EOO occurred more frequently than LOO. Idiopathic occipital syndromes diagnosis was possible in 63.4% of the cases.     

The localizing value of ictal EEG in focal epilepsy.

OBJECTIVE: To investigate the lateralization and localization of ictal EEG in focal epilepsy. METHODS: A total of 486 ictal EEG of 72 patients with focal epilepsy arising from the mesial temporal, neocortical temporal, mesial frontal, dorsolateral frontal, parietal, and occipital regions were analyzed. RESULTS: Surface ictal EEG was adequately localized in 72% of cases, more often in temporal than extratemporal epilepsy. Localized ictal onsets were seen in 57% of seizures and were most common in mesial temporal lobe epilepsy (MTLE), lateral frontal lobe epilepsy (LFLE), and parietal lobe epilepsy, whereas lateralized onsets predominated in neocortical temporal lobe epilepsy and generalized onsets in mesial frontal lobe epilepsy (MFLE) and occipital lobe epilepsy. Approximately two-thirds of seizures were localized, 22% generalized, 4% lateralized, and 6% mislocalized/lateralized. False localization/lateralization occurred in 28% of occipital and 16% of parietal seizures. Rhythmic temporal theta at ictal onset was seen exclusively in temporal lobe seizures, whereas localized repetitive epileptiform activity was highly predictive of LFLE. Seizures arising from the lateral convexity and mesial regions were differentiated by a high incidence of repetitive epileptiform activity at ictal onset in the former and rhythmic theta activity in the latter. CONCLUSIONS: With the exception of mesial frontal lobe epilepsy, ictal recordings are very useful in the localization/lateralization of focal seizures. Some patterns are highly accurate in localizing the epileptogenic lobe. One limitation of ictal EEG is the potential for false localization/lateralization in occipital and parietal lobe epilepsies.     

Clinical and EEG evaluation of mid-line spikes in childhood

We studied the clinical and electroencephalographic (EEG) characteristics of 45 patients with mid-line spikes. The incidence of mid-line spikes was 3.0% in total EEG population in childhood. Sex incidence was equal. First appearance age of mid-line spikes ranged from one month to 12 years, with a mean of 5.0 years old. Fz focus was in 3 patients, Cz in 31 and Pz in 11. Thirty two of the 45 patients (71%) had a history of clinical seizures; 16 with febrile convulsions and 16 with epileptic seizures. Of the remaining 13 patients without a history of seizures, the EEG was obtained because of post-meningitis in 4, developmental delayed in 4, migraine in 1 and miscellaneous in 4. Mid-line spikes might not have so strong correlations with clinical seizures. Ten patients had a family history of epilepsy and/or febrile convulsion. In the patients with seizures, generalized tonic-clonic seizures were the most frequent type (18; primary GTC and 10; secondary GTC with partial onset). Elementary symptoms of partial seizures were very variable (focal motor in 5, Jacksonian march in 1, aversive in 1, autonomic in 2 and automatism in 5), and which might be related to the other lesions such as temporal and/or frontal lobes. Seizure control was almost good except for two patients with organic brain damage. And other neurological symptoms were not also progressive. On EEG findings, twenty-two patients had midline spikes as their only epileptiform abnormality. The remaining twenty-three had an additional epileptiform feature, either a focal spikes or a generalized spike-wave.(ABSTRACT TRUNCATED AT 250 WORDS)     

Longitudinal study of epileptiform EEG patterns in normal children

EEG were recorded in 3,726 children, from 6 to 13 years of age who were neurologically normal and had no history of epileptic seizures. The records were taken during wakefulness, at rest, and during hyperventilation. In 131 cases (3.54%) epileptiform patterns were found. They consisted of 3 count/sec spike and slow waves discharges (4 cases), multiple spike and slow wave complexes (37 cases), midtemporal spikes (50 cases), rolandic or parietal spikes (27 cases), occipital spikes (2 cases), and multifocal spikes (11 cases). Half of the subjects with EEG abnormalities had behavior problems and/or slight psychomotor ability disturbances. Follow-up studies over an 8 to 9 year period were performed. These demonstrated the spontaneous disappearance of the EEG abnormalities, usually within school age or, at the latest, during adolesence. Only seven individuals developed epileptic seizures of the primary generalized type which responded well to anticonvulsant drug treatment. From this study we can deduce that the epileptiform EEG patterns that often are found in children during school age have no clinical relationship to epilepsy in the great majority of cases. The relationship with epilepsy exists probably on a genetic level for the generalized discharges. The spike foci are non-epileptic in nature in all probability, especially if they emerge from a fairly normal background activity and their duration is very similar to that of the constituents of the background activity, as found in the majority of these subjects. On the contrary, it is probable that these alterations express difficulties in affective or motor adaptation during childhood.