Macular pigment and lutein supplementation in retinitis pigmentosa and Usher syndrome.

PURPOSE: To determine macular pigment (MP) in patients with inherited retinal degeneration and the response of MP and vision to supplementation of lutein. METHODS: Patients with retinitis pigmentosa (RP) or Usher syndrome and normal subjects had MP optical density profiles measured with heterochromatic flicker photometry. Serum carotenoids, visual acuity, foveal sensitivity, and retinal thickness (by optical coherence tomography [OCT]) were quantified. The effects on MP and central vision of 6 months of lutein supplementation at 20 mg/d were determined. RESULTS: MP density in the patients as a group did not differ from normal. Among patients with lower MP, there was a higher percentage of females, smokers, and light-colored irides. Disease expression tended to be more severe in patients with lower MP. Inner retinal thickness by OCT correlated positively with MP density in the patients. After supplementation, all participants showed an increase in serum lutein. Only approximately half the patients showed a statistically significant increase in MP. Retinal nonresponders had slightly greater disease severity but were otherwise not distinguishable from responders. Central vision was unchanged after supplementation. CONCLUSIONS: Factors previously associated with lower or higher MP density in normal subjects showed similar associations in RP and Usher syndrome. In addition, MP in patients may be affected by stage of retinal disease, especially that leading to abnormal foveal architecture. MP could be augmented by supplemental lutein in many but not all patients. There was no change in central vision after 6 months of lutein supplementation, but long-term influences on the natural history of these retinal degenerations require further study.

Seizure localization and pathology following head injury in patients with uncontrolled epilepsy.

We studied seizure localization and surgical pathology in 25 patients who developed intractable complex partial seizures following head trauma. All patients underwent an extensive presurgical evaluation that included MRI, neuropsychological evaluation, and surface EEG monitoring, and 21 had intracranial EEG monitoring. Seizures were successfully localized in nine patients; all nine underwent a surgical procedure and are seizure-free. Six of these patients had a mesial temporal lobe seizure focus, of whom five had a pathologic diagnosis of mesial temporal sclerosis. All five patients who developed mesial temporal sclerosis sustained their head injury at or before age 5 years. The three remaining patients whose seizures were successfully localized had neocortical foci and circumscribed radiographic abnormalities, which were presumed to be secondary to head trauma, and all had successful surgical resections of the epileptogenic focus. The remaining 16 patients sustained later trauma, and all had successful surgical resections of the epileptogenic focus. The remaining 16 patients sustained later trauma and did not have a focal MRI lesion, and their seizures were not adequately localized. We conclude that as a group, seizure foci secondary to head trauma are difficult to localize accurately, and this should deter surgical intervention. There was an association between early head injury (ie, at or before age 5 years) and mesial temporal sclerosis, and this association aided seizure localization and successful surgical intervention. Therefore, under the right circumstances, trauma can be a suitable historical element in the profile of patients in whom epilepsy surgery is successful.

Migraine-related seizures in adults with epilepsy, with EEG correlation.

We studied the relationship between migraine and epilepsy in 395 adult seizure patients. Seventy-nine patients (20%) also had migraine syndrome, and 13 of these patients (3%) experienced seizures during or immediately following a migraine aura. Patients with catamenial epilepsy and patients with migraine with aura were at an increased risk for an association between these two disorders. In two patients, we recorded the entire sequence from migraine aura to partial seizure, and in both there were distinctive changes on the EEG during the migraine aura that preceded the onset of an electrographic complex partial seizure. Periodic lateralized epileptiform discharges were recorded in five other patients in close temporal relation to their migraine attacks. There was improved seizure control with combination antimigraine and antiepileptic drugs (AEDs) in six patients who failed to respond to AEDs alone.

Characteristics of intractable seizures following meningitis and encephalitis.

We studied clinical seizure characteristics, seizure localization, and pathology in 38 patients who developed medically intractable partial seizures following meningitis (n = 16) or encephalitis (n = 22) and were evaluated for epilepsy surgery. Whereas meningitis in this group was commonly associated with mesial temporal sclerosis (MTS), most encephalitis patients had neocortical foci. The age of onset of the encephalitic illness was important in predicting mesial temporal or neocortical foci in that group: encephalitis before, but not after, age 4 years was associated with MTS. Since almost all meningitis occurred before age 4 years, these data support the hypothesis that the medial temporal lobe is particularly susceptible to early insults, establishing the initial pathologic entity of MTS and the subsequent cascade of partial seizures. Later-onset encephalitis produced extrahippocampal neocortical seizure foci, was rarely associated with MRI abnormality, and was difficult to localize precisely. In contrast, meningitis was commonly associated with MTS, aiding seizure localization and successful surgical intervention when seizures were medically uncontrolled.

Frontal lobe partial seizures and psychogenic seizures: comparison of clinical and ictal characteristics.

Of all partial seizures, those of frontal lobe origin (FLPS) are most bizarre and are often mistaken for psychogenic seizures (PS). The reverse can also be true. To clarify the confusing clinical presentation of these different seizure types, we compared the clinical ictal characteristics of 63 FLPS in 11 patients with 29 PS in 12 patients. Patients with PS had significantly later age at onset and longer ictal duration. There was no statistically significant difference between the two groups with respect to history of psychiatric disorder, ictal pelvic thrusting, rocking of body, side-to-side head movements, or rapid postictal recovery, all of which previously have been reported as characteristic features of PS. Turning to a prone position during the seizure occurred only in FLPS. Nocturnal occurrence, short ictal duration, younger age at onset, stereotyped patterns of movements, and MRI and EEG abnormality suggested FLPS.

Localization of extratemporal epileptic foci during ictal single photon emission computed tomography.

We obtained single photon emission computed tomography (SPECT) scans with technetium-99M-hexamethyl-propylene-amine-oxime in 11 patients during 12 extratemporal partial seizures (9 simple partial, 3 complex partial). Ten ictal SPECT studies in 9 patients showed a focal region of hyperperfusion, which agreed with electrical seizure onset in 5 and with clinical seizure localization in 4 in whom ictal electroencephalography was not localized. Contralateral cerebellar and ipsilateral basal ganglia hyperperfusion was seen in 3 patients with a frontal lobe seizure focus. Ictal hyperperfusion was well circumscribed, unlike the diffuse hyperperfusion changes reported during temporal lobe seizures. This observation may indicate a different degree of seizure spread in temporal as opposed to extratemporal epilepsy. Because electroencephalographic localization is often elusive in extratemporal seizures, ictal SPECT may be very helpful for the localization of extratemporal foci.

Comparison and correlation of surface and sphenoidal electrodes with simultaneous intracranial recording: an interictal study.

We prospectively compared and correlated interictal spikes recorded with simultaneous surface, sphenoidal, depth and subdural electrodes in 21 patients. Although the amplitude of sphenoidal spikes was often larger than that of surface spikes in patients with mesial basal temporal ictal and interictal foci, only 1 patient had exclusively sphenoidal spikes. Spikes with maximal amplitude at the sphenoidal electrode arose from mesial temporal, temporal neocortical and orbital frontal foci. An inferior vertical temporal dipole (hippocampal positive and inferior temporal neocortex negative) was associated with surface and sphenoidal spikes.

Does interictal spiking change prior to seizures?

We studied 10 patients with intractable epilepsy being evaluated for epilepsy surgery for preictal changes in spiking. All patients were implanted with intracranial electrodes and underwent continuous EEG/audiovisual monitoring. Interictal spikes were detected and recorded continuously by a dedicated computerized system. Edited spikes were counted during 0-5, 5-10, and 0-60 min epochs before each seizure, during epochs of unvarying state of arousal (awake or sleep stage II). When comparing by repeated measures, 1-way ANOVA, total spiking (in all recording channels) did not differ among the different preictal epochs (0-5, 5-10, 0-60 min) in 45 seizures (F = 0.88, P = 0.40, using the Geisser-Greenhouse adjustment--GGA). Likewise, no significant differences were obtained during those same epochs when comparing spiking originating from the channel of seizure onset in 5 patients with 28 seizures of localized onset (F = 1.19, P = 0.38 using the GGA). Our findings indicate that in patients with intractable epilepsy, no changes in spiking occur in the 5 min prior to seizures, when compared to more distant preictal epochs.

Clinical and electrographic effects of acute anticonvulsant withdrawal in epileptic patients.

We retrospectively investigated the effects of acute antiepileptic drug (AED) withdrawal on seizure symptomatology--including frequency, clinical features, and electrical onset--by studying 35 patients during evaluation for epilepsy surgery. The highest risk for both partial and secondary generalized seizures occurred during absent or subtherapeutic, and not during rapidly falling, AED levels. AED withdrawal had minimal effect on clinical symptomatology or electrographic onset.