Language assessment in Wada test: Comparison of methohexital and amobarbital

AbstractIntroductionMethohexital 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.MethodsA 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.ResultsLanguage 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.DiscussionLanguage 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

Valproic acid use in pediatric partial epilepsy after initial medication failure

We retrospectively identified 46 children and adolescents with partial epilepsy, who failed prior treatment with phenytoin, carbamazepine, phenobarbital and/or primidone. All patients were subsequently treated with valproate (VPA). Outcome measurements were stratified into seizure type, simple partial seizures (SPS), complex partial seizures (CPS) or secondarily generalized seizures (SGS), or lesions detected by magnetic resonance images (MRI). The majority of the patients had a ≥ 75% reduction of seizure frequency. Complete seizure freedom was achieved in 7 (15%) patients. "Worthwhile" seizure reduction, defined as ≥ 75% decrease (but < 100%) in seizure activity, was found in 30 (65%) patients. VPA was efficacious in SPS (2/2), CPS (9/12) and SGS (26/32) patients. Patients with MRI lesions of vascular insult (6/6), mesial temporal lobe sclerosis (8/10), or malformation of cortical development (6/7) had a higher response percentage than those patients with normal MRI findings (11/15) and tumors (5/7). Although the numbers of patients used in this study were too small for statistical significance, our results suggest that VPA is a useful medication for previous medication failures in childhood partial seizures across seizure types as well as MRI lesions. There is some suggestion that a higher percentage of patients with MRI lesions may respond favorably to VPA than patients with non-lesional partial seizures and tumors. (J Pediatr Neurol 2004; 2(4): 199-203)

Postictal Psychiatric Events During Prolonged Video-Electroencephalographic Monitoring Studies

BACKGROUND: Postictal psychiatric events presenting as postictal psychotic events and postictal nonpsychotic events are known to occur following seizure clusters. Accordingly, patients undergoing prolonged video-electroencephalographic (EEG) monitoring studies may be at increased risk of experiencing a postictal psychiatric event, as they often have flurries of seizures during these studies. OBJECTIVES: To determine the annual incidence and clinical characteristics of postictal psychotic events and postictal nonpsychotic events in video-EEG monitoring studies in patients with partial seizure disorders and to identify potential pathogenic factors. RESULTS: Thirteen patients met the criteria for a postictal psychiatric event during the 18-month study period, 10 presenting as postictal psychotic events and three as postictal nonpsychotic events. The annual incidence of postictal psychiatric events at our monitoring unit for 1988 was 7.8%, 6.4% presenting as postictal psychotic events and 1.4% as postictal nonpsychotic events. Seven patients had their first-ever postictal psychiatric event during the monitoring study. In 12 of the 13 patients, the postictal psychiatric events mimicked well-defined psychiatric entities of shorter duration (mean, 66.5 hours); they appeared 12 to 72 hours after the last seizure and remitted spontaneously or with the use of low-dose psychotropic medication. No significant differences in EEG, neuroradiologic, psychiatric, medical, or psychosocial data were found between the patients with postictal psychiatric events and a group of 13 age-matched control patients. Follow-up data of comparable duration were available in nine patients with postictal psychiatric events and nine controls. Psychiatric events were reported more frequently by patients with postictal psychiatric events than by control patients (P=.03). In three patients, postictal psychiatric events converted to interictal events. CONCLUSION: These findings suggest that monitoring studies increase the risk for postictal psychiatric events, which neurologists need to be familiar with, as they represent important morbidity associated with these studies

Hypomotor seizures in infants and children.

PURPOSE: Hypomotor seizures (characterized by diminished behavioral activity with indeterminate level of consciousness) have been identified as an important seizure type in infants. Our goal was to investigate further the clinical and EEG features of hypomotor seizures. METHODS: We retrospectively reviewed 110 hypomotor seizures from 34 patients recorded with video-EEG. RESULTS: Twenty-seven (79%) patients were younger than 48 months, and seven (21%) were aged 4 to 15 years. Seventy-one (64%) seizures had regional or lateralized EEG onset, arising predominantly from temporal or parietal lobe regions. The other 39 (35%) seizures had generalized onset, usually with abrupt onset of diffuse rhythmic high-amplitude theta activity or diffuse electrodecrement and only rarely (two patients) with slow spike-wave complexes or 3-Hz spike-wave complexes. Hypomotor seizures with generalized EEG onset were significantly shorter than those with regional or lateralized onset (p = 0.01, GEE model). Unsustained head or eye movements and subtle mouth automatisms were commonly seen in hypomotor seizures with either focal or generalized onset. Seventeen percent of hypomotor seizures with focal onset evolved to include version of head and eyes or jerking of one arm, whereas 2% of generalized hypomotor seizures evolved to a cluster of spasms. CONCLUSIONS: Hypomotor seizures may be either focal or generalized. Regional EEG onsets were most often temporal or parietal, suggesting that focal hypomotor seizures may be a bland form of "complex partial" seizures with no or minimal automatisms, seen predominantly in infants. Generalized hypomotor seizures were rarely associated with an ictal pattern of generalized spike-wave complexes, suggesting a different mechanism from absence seizures seen later in life

A Potential Novel Mechanism for Vagus Nerve Stimulator-Related Central Sleep Apnea

The treatment of epilepsy with vagus nerve stimulation can inadvertently cause obstructive and central sleep apnea (CSA). The mechanism for CSA seen in patients with a vagus nerve stimulator (VNS) is not fully known. We describe the case of a 13-year-old girl in whom VNS activation induced tachypnea and post-hyperventilation central apnea. Following adjustment of VNS settings, the post-hyperventilation CSA resolved. Polysomnography may assist with management when patients with epilepsy develop sleep disruption after VNS placement