Language assessment in Wada test: comparison of methohexital and amobarbital.

INTRODUCTION: Methohexital has replaced amobarbital during Wada testing at many centers. The objective of our study was to compare the use of methohexital and amobarbital during Wada testing regarding language and memory lateralization quotients as well as speech arrest times. METHODS: A chart review of 582 consecutive patients undergoing 1041 Wada-procedures was performed (left=60, right=63, bilateral=459). Language lateralization was calculated based on duration of speech arrest using a laterality index, defined as (L-R)/(L+R). Memory lateralization was expressed as percentage of retained objects and laterality quotient. RESULTS: Language and memory lateralization revealed a similar distribution with amobarbital and methohexital. Speech arrest after left and right-sided injection was significantly longer in the amobarbital group as compared to the methohexital group. Language lateralization did not differ in the two groups. Percentage of retained memory items was higher in the methohexital group and there were fewer presented test items in the methohexital group. DISCUSSION: Language and memory testing during the Wada test can successfully be performed with methohexital instead of amobarbital. The shorter half-life of methohexital allows repeated injections and shorter interhemispheric testing intervals, but also shortens the testing window.

Non-epileptic seizures of the elderly.

OBJECTIVE: To characterize non-epileptic seizures (NES) in the elderly and compare their features with NES of a younger control group. METHODS: The database of the epilepsy monitoring unit of the Cleveland Clinic Foundation (CCF) was searched for patients aged 60 years and older having undergone long-term video-/EEG monitoring between 1994 and 2002, with the subsequent diagnosis of NES. Videotapes of all events were evaluated by independent observers. NES were classified based on the clinical manifestations recorded on video, EEG and imaging data, and compared with a control group of younger adults with NES. RESULTS: Thirty-nine elderly patients were included. Seventeen of them (44%) had NES only, six (15%) had both epilepsy and NES. The control group consisted of 20 patients, two of them had NES and epilepsy. The NES were classified as physiological in 10 elderly patients (43%) and one control patient. They included TIA, syncope, movement disorders and sleep disorders. Psychogenic NES were found in 13 elderly and 19 control patients and were associated with somatoform disorders, anxiety disorders, mood disorders and reinforced behavior pattern. Psychogenic NES consisted of predominant motor activity in 8 (61%) elderly and 13 (68%) control patients, unresponsiveness in 4 (31%) elderly and 2 (11%) control patients and subjective symptoms in 1 (8%) elderly and 4 (21%) control patients. Twelve (71%) of the patients of each group without evidence for epilepsy were on anticonvulsant drugs at the time of admission. CONCLUSION: NES are a frequent problem in elderly patients referred to a comprehensive epilepsy center. In contrast to a younger control group, physiological and psychogenic NES are equally frequent in the elderly. Loss of responsiveness was seen in only 20% of patients with psychogenic NES. Although most of the patients did not have any evidence for epilepsy, more than two thirds of these patients had been placed on anticonvulsive drugs.

Seizure semiology in the elderly: a video analysis.

PURPOSE: To describe the seizure semiology of patients older than 60 years and to compare it with that of a control group of younger adults matched according to the epilepsy diagnosis. METHODS: Available videotapes of all patients aged 60 years and older who underwent long-term video-EEG evaluation at the Cleveland Clinic Foundation (CCF) between January 1994 and March 2002 were analyzed by two observers blinded to the clinical data. A younger adult control group was matched according to the epilepsy diagnosis, and their seizures also were analyzed. RESULTS: Fifty-four (3.3%) of the 1,633 patients were 60 years or older at the time of admission. For 21 of them, at least one epileptic seizure was recorded. Nineteen patients had focal epilepsy (nine temporal lobe, two frontal lobe, two parietal lobe, eight nonlocalized), and two patients had generalized epilepsy. Seventy-three seizures of the elderly patients and 85 seizures of the 21 control patients were analyzed. In nine elderly patients and 14 control patients, at least one of their seizures started with an aura. Eleven elderly patients and 19 control patients lost responsiveness during their seizures. Approximately two thirds of the patients in both groups had automatisms during the seizures. Both focal and generalized motor seizures (e.g., clonic or tonic seizures) were seen less frequently in the elderly. CONCLUSIONS: Only a small percentage of the patients admitted to a tertiary epilepsy referral center for long-term video-EEG monitoring are older than 60 years. All seizure types observed in the elderly also were seen in the younger control group, and vice versa. Simple motor seizures were seen less frequently in the elderly.

Effect of sleep on epilepsy.

There is an extremely intimate relationship between sleep and epilepsy. In this manuscript I will review the influence that sleep has on epilepsy. Sleep is a potent activator of interictal epileptiform discharges. Sharp waves are infrequent during wakefulness in benign focal epilepsy of childhood, but may occur in runs of several discharges per page in sleep. The interictal discharges become almost continuous in non-REM sleep in the syndrome of encephalopathy with electrical status epilepticus during slow wave sleep. In some patients with West syndrome a hypsarrhythmia pattern may only appear in sleep whereas in others there may be an increase in discharges in a semiperiodic fashion resulting in a burst-suppression like pattern. Seizures appear to have a very close relationship with sleep in certain epilepsy syndromes. In benign focal epilepsy of childhood the seizures occur almost exclusively in sleep, while supplementary sensorimototor area seizures tend to occur in clusters during sleep. Juvenile myoclonic epilepsy has a close relationship with the sleep-wake cycle with seizures tending to occur predominantly on awakening. I also discuss the role of sleep and sleep deprivation in the EEG evaluation of epilepsy.

EEG and evoked potential recording from the subthalamic nucleus for deep brain stimulation of intractable epilepsy.

OBJECTIVES: The substantia nigra in the animal model has been implicated in the control of epilepsy. The substantia nigra pars reticulata (SNpr) receives afferents from the subthalamic nucleus (STN), which thus may have an effect on the control of epilepsy. There is evidence in the animal model of a direct connection from the cortex to the STN. High-frequency STN stimulation is being used in experimental trial for the management of intractable epilepsy. Our primary objective in this study was to determine if there was epileptiform activity recorded from the STN in association with scalp recorded epileptiform activity to support the presence of a pathway from the cortex to the STN in humans as described in animals that may be important for the management of epilepsy. This article describes the interictal and ictal electroencephalographic (EEG) findings as well as evoked potential recordings from the STN in these patients with intractable epilepsy. METHODS: Four patients (3 males) ranging from 19 to 45 years with intractable focal epilepsy refractory to anti-epileptic drugs were studied. Two patients failed vagal nerve stimulation and one patient had previous epilepsy surgery. Depth electrodes were implanted stereotactically in the STN bilaterally. A comparative analysis of the interictal and ictal activities recorded from the scalp and STN electrodes was performed. Median nerve somatosensory evoked potentials (SEPs) and auditory evoked potentials (AEPs) were also recorded. RESULTS: Interictal sharp waves recorded in the scalp EEG were always negative in polarity. These sharp waves were always associated with sharp waves recorded at the ipsilateral STN electrode contacts that were always positive in polarity. In addition repetitive spikes were recorded independently at the left or right STN electrode contacts, with no reflection at the scalp. These spikes were extremely stereotyped, of high amplitude and short duration, and were positive or negative in polarity. Focal scalp EEG seizures were also recorded at the ipsilateral STN electrodes. In 3 patients SEPs were recorded from the contralateral STN electrodes corresponding to the P14/N18 far-field complex. In two patients AEPs were recorded, and wave V (near-field) and wave VII (far-field) from the contralateral STN electrodes. CONCLUSIONS: This study demonstrates that scalp recorded epileptiform activity is reflected at the ipsilateral STN either following or preceding the scalp sharp waves. The STN sharp waves are most probably an expression of the direct cortico-STN glutamatergic pathways that have been demonstrated previously in animals. This pathway in man may be important with regard to a possible mechanism for the treatment of epilepsy with STN stimulation.

Sleep-related eating disorder in fraternal twins.

Sleep-related eating disorder (SRED) is characterized by nocturnal partial arousals associated with compulsive consumption of food and altered levels of consciousness. Reports of an increased incidence of SRED in relatives of affected individuals suggest a genetic predisposition. We report a woman with SRED whose fraternal twin sister and father are also affected.

Prediction of the final MSLT result from the results of the first three naps.

OBJECTIVES: To determine if the mean sleep latency (mSL) and the presence of significant sleep onset rapid eye movement periods (SOREMPs) can be predicted from the results of the first three naps in selected patients undergoing multiple sleep latency test (MSLT). METHODS: Retrospective analysis of a number of MSLTs to identify the tests in which the mSL category and the presence of > or =2 naps with SOREMPS can be accurately predicted from the sleep latencies (SLs) of and SOREMPs in the first three naps. RESULTS: The study included 588 consecutive MSLTs performed on 552 patients during a 3-year period. (1) The mSL was normal (> or =10 min) for all MSLTs (n=90, 15%) if either (a) the SL was normal in each of the first three naps, or (b) SL was 20 min for any two of the first three naps. (2) The mSL was low (<5 min) or borderline (> or =5 and <10 min) for 99% MSLTs with SL in the low or borderline categories, respectively. (3) The accuracy of predicting > or =2 naps with SOREMPs was 100% (normal SL), 96% (borderline SL), and 89% (low SL). (4) The mSL category (normal or low) and the presence of > or =2 naps with SOREMPs were predicted with 100% accuracy in 23% of all MSLTs. CONCLUSIONS: The category of mSL can be predicted with >99% accuracy, if SL is normal, borderline, or low in each of the first three naps, or if the patient does not sleep in any two of the first three naps. MSLT can probably be shortened to three naps in up to 23% to reduce time, labor, discomfort, and cost of the test.