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Biomedical subjects

M E Drake

Publications and source records attributed to M E Drake.

At least 55 records · Page 3Linked to original sources
PubMed1991

Sleep spindles in epilepsy.

Spindles are a ubiquitous phenomenon in sleep, but their physiology and the effects of neurologic disorder on their frequency and amplitude are incompletely understood. We compared the incidence of three commonly defined spindle types (14-15 Hz, 12-13 Hz, and 10 Hz) and the frequency and amplitude of spindles during Stage II sleep in 50 patients with complex partial, partial and secondarily generalized, and primary generalized seizures, with and without interictal behavioral symptoms. All patients had 12-13 Hz and 14-15 Hz spindles of symmetric character in C3-A1 and C4-A2 derivations during prolonged sleep-deprived EEG recordings, which were normal except for partial or generalized epileptiform activity. Seventy-one per cent of complex partial seizure patients had 10 Hz spindles, and they occurred in 50% of the other two groups, predominating among those with interictal behavioral symptoms in all groups. Spindle frequency was significantly less in patients with generalized epilepsy than with partial seizures, and patients with complex partial seizures and partial seizures with secondary generalization differed significantly in spindle frequency. Spindle frequency was significantly lower with polypharmacy than with monotherapy. Patients whose regimens included phenobarbital had significantly lower spindle frequencies and spindle frequencies differed significantly between phenytoin and carbamazepine. Differences in spindle frequency may be due to residual medication effects, underlying encephalopathy or physiological differences between partial and generalized epilepsy.

Adolescent↗
PubMed1991

Auditory evoked potentials in borderline personality disorder.

Borderline personality disorder is an increasingly recognized condition and frequent management problem in psychiatric and nonpsychiatric practice. Paroxysmal changes in affect and behavior, high incidence of soft neurologic signs and frequent EEG alterations, and evidence of clinical response to antiepileptic drugs have suggested cerebral dysfunction, particularly involving the limbic system or reticular activating system. We recorded early latency brainstem auditory evoked potentials (BAEPs) and long-latency auditory event-related potentials (ERPs) in 20 patients fulfilling DSM-III-R criteria for this disorder. BAEPs were recorded from Cz to ipsilateral and contralateral ear reference, with rarefaction clicks presented at 11.1 per second and 70 dB SL. Two thousand averages were recorded and replicated for each ear, with filter band pass of 150-3000 Hz and 10 ms analysis time. ERPs utilized binaural stimulation with 1000 and 3000 Hz tones in an 80:20 ratio, with interstimulus interval 1.1 second, analysis time 1000 ms, and filter band pass 1-100 Hz. Two hundred averages were recorded and replicated from Cz with linked ear reference. No differences were evident in I-III, III-V, and I-V interpeak latencies between borderline patients and age-matched neurologically and audiologically normal controls. N1, P2, and N2 components of the AEPs were longer in latency and lower in amplitude in borderline patients, while P3 latency was longer and amplitude was attenuated in borderline patients as compared to controls. These findings may suggest differences from normals in attention maintenance and in limbic system function.

Adult↗
PubMed1991

Computerized EEG frequency analysis in Gilles de la Tourette syndrome.

EEG abnormality has been reported in Gilles de la Tourette Syndrome but not confirmed in later studies. We carried out computerized EEG frequency analysis in 30 patients with the disorder, using Nicolet Pathfinder II frequency analysis software, versions 1.2 and 3.1 EEG was recorded from 01-A1+A2, 02-A1+A2, Fz-A1+A2, F7-C3, F8-C4, T5-01, and T6-02 in Tourette Syndrome patients and controls. Controls were taking no medications, and drug therapy for Tourette Syndrome had been stopped or not yet initiated in the patient group. Modal alpha frequency (MAF), maximal alpha frequency (MxAF), and spectral edge frequency (SEF) was measured in occipital and frontal derivations in 24 patients and controls. Left frontal (MOLF) and right frontal (MORF) mobility was calculated in F7-C3 and F8-C4 in 21 patients and controls. No significant differences were found between Tourette Syndrome patients and controls by two-tailed t-test. These findings are in accord with recent evidence of little or no EEG abnormality in Tourette Syndrome patients as compared to normals.

Adolescent↗
PubMed1991

Neuropsychiatric aspects of psychogenic status epilepticus.

We studied 20 patients with continuous repetitive psychogenic seizures simulating status epilepticus. Most patients received intravenous doses of multiple anticonvulsants. Our definition used for status epilepticus was that of Delgado-Escueta et al, at least 30 minutes of repetitive seizures without regaining consciousness. Nineteen of 20 patients were young women, all but one under 40 years of age. Sixteen of these patients had a history of childhood seizures. In over 50% of patients, seizures continued until respiratory arrest and intubation occurred. Thorough neuropsychological testing and psychiatric interview were done after cessation of the acute episode. Long-term outcome and prognosis depended on definitive psychiatric diagnosis. Repetitive psychogenic seizures simulating status epilepticus are not uncommon, and such patients may incur serious iatrogenic complications from treatment for status epilepticus. Appropriate management and long-term prognosis may be determined by the type and severity of the underlying psychiatric disorder.

Adult↗
PubMed1991

Amantadine hydrochloride for refractory generalized epilepsy in adults.

Amantadine hydrochloride has been shown in several open studies to benefit children with refractory generalized epilepsy. We used amantadine as adjunctive therapy in 10 adolescents and adults with generalized tonic-clonic, myoclonic, or absence seizures refractory to therapeutic levels of valproate, carbamazepine, phenytoin, and benzodiazepines. Seven patients were men and 3 were women aged 18-29 years, and 8 of 10 patients were mentally retarded. All patients had generalized epileptiform paroxysms on EEG, with generalized or absence seizure recorded in 9. Five patients had both absence and tonic-clonic seizures, and 2 had all three seizure types. Amantadine was added to the existing regimens in weekly increments to 400 mg/day. Two patients had greater than 90 per cent seizure reduction, both with vomiting and somnolence. Two patients had seizure reduction between 50 and 90 per cent, 1 with anorexia and sleepiness. Three patients had no change in seizures, and 3 had worse tonic-clonic seizures. Amantadine may have some antiepileptic efficacy of unknown mechanism, but it may worsen generalized tonic-clonic seizures and is likely to be of limited value in adults.

Adolescent↗
PubMed1990

Nocturnal sleep recording with cassette EEG in chronic headaches.

Many headache patients complain of poor sleep, and sleep disturbance has been shown to play a role in chronic pain. We recorded nocturnal sleep with a 4-channel cassette EEG monitoring device in 10 common migraine patients, 10 individuals with muscle contraction (tension) headache, and 10 chronic tension-vascular headache sufferers. Migraine patients had essentially normal sleep, although rapid eye movement (REM) sleep and REM latency were increased. Patients with tension headache had reduced sleep time and sleep efficiency, decreased sleep latency but frequent awakenings, increased nocturnal movements, and marked reduction in slow wave sleep, without change in REM sleep or latency. Mixed-element headaches with both tension and vascular features were associated with reduced sleep, increased awakening, diminished slow wave sleep, and REM sleep that was decreased in amount and reduced in latency. The findings suggest that patients with intermittent migraine may have minimal sleep disturbance, while chronic headache may be worsened by chronically poor sleep. Muscle contraction headache may be associated with frequent awakenings and decreased slow wave sleep similar to the sleep changes of fibrositis, while chronic tension-vascular headache may have a depressive substrate. Four-channel sleep recording may miss contributory sleep apnea, but nonetheless cassette EEG may facilitate outpatient evaluation of refractory headaches.

Adult↗
PubMed1990

Secondary mania after ventral pontine infarction.

Secondary mania is increasingly recognized clinically, and consists of acute exhibition of manic symptoms without past or family history of affective disorder. It has been reported with toxic and metabolic disturbances, primary and metastatic brain tumors, epilepsy, and cerebrovascular events. A multifactorial etiology has been suggested. We report two men, 52 and 56 years old, who developed grandiosity, sleeplessness, irritable mood, hyperactivity, and paranoid and religious delusions, with attempted violence in one case. Both had no premorbid psychiatric history and were healthy except for hypertension. One patient had a normal neurologic examination, and the other had mild left hemiparesis and hyperreflexia. EEGs, brainstem auditory-evoked responses, and median nerve somatosensory-evoked potentials were normal. Magnetic resonance studies demonstrated infarction of the ventral pons (on the right in the patient with left-sided signs and on the left in the patient with normal neurologic examination). The two patients responded to lithium carbonate and neuroleptics and have not had further psychiatric symptoms in 18 months of follow-up. These cases emphasize the relationship of late-onset mania with predisposing brain disease, and they suggest that brainstem disturbances can influence mood, sleep, libido, and thought.

Bipolar Disorder↗
PubMed1990

Auditory evoked potentials in vertebrobasilar transient ischemic attacks.

Brainstem auditory evoked potentials (BAEPs) are affected by stroke or migraine in the vertebrobasilar arterial system. Some studies have reported BAEP changes in vertebrobasilar transient ischemic attacks (TIAs), but others have shown no alterations. We recorded BAEPs in 35 patients with TIAs in the vertebrobasilar system who did not have a stroke, other neurologic disease or significant hearing loss. Thirty patients were recorded after resolution of symptoms, while five individuals still had some resolving signs or symptoms. TIA patients as a group had longer interpeak latencies, but I-III, III-V, and I-V latencies were not significantly longer than in controls. Wave V was significantly longer in latency and lower in amplitude in TIA patients, however. The patients whose TIAs had resolved at absolute and interpeak latencies were within normal limits, but three of five had interpeak latencies at or above three standard deviations beyond the normal mean in the still symptomatic group. One of these was later tested and found to be within normal limits. BAEPs after subsidence of symptoms may add little to the evaluation of vertebrobasilar ischemia, but further AEP analysis may show more definitive differences of diagnostic use. The occasional BAEP abnormality during the resolving transient ischemia supports the recently suggested continuum between ischemia and infarction in the vertebrobasilar territory.

Aged↗
PubMed1990

Brainstem auditory evoked responses in partial and generalized seizures.

This study presents clinical neurophysiologic evidence of altered upper brainstem function in patients with generalized epilepsy who do not otherwise differ clinically from the general population. While the differences in absolute latencies are not great enough to support the use of BAERs in routine evaluation, this data does support experimental studies implicating brainstem structures in the pathophysiology of primary generalized epilepsy. The lack of evidence of brainstem involvement in complex partial seizures may suggest a mechanism of seizure spread that is not dependent upon primary brainstem pathology, or may indicate that any brainstem abnormality in epilepsy may involve areas not mediating transmission of auditory stimuli and therefore not assessed by BAERs.

Adult↗
PubMed1990

Outpatient sleep recording during antiepileptic drug monotherapy.

The effects of sleep and sleep deprivation on epilepsy are well known, but the effects of seizures and antiepileptic drugs (AEDs) on sleep have been less well studied. We recorded nocturnal sleep in 17 patients receiving antiepileptic monotherapy with ambulatory cassette EEG devices. Twelve patients had complex partial seizures and five had tonic-clonic convulsions. Two patients' seizures were largely nocturnal, and no seizures occurred during sleep recording. Five patients each were taking phenytoin (PHT), carbamazepine (CBZ), and valproate (VPA), and two were taking clonazepam (CZP), all with therapeutic serum levels and no toxic symptoms. Total sleep time was reduced, wakefulness increased, and sleep latency prolonged in partial seizures as compared with generalized epilepsy. REM sleep was reduced and its latency decreased in partial seizure patients. Both groups had decreased slow wave sleep; that of partial seizure patients was decreased more markedly. PHT increased sleep latency and decreased sleep time, and CBZ increased awakening and diminished slow wave and REM sleep. Patients taking VPA had slight reduction in slow wave sleep; those taking CPZ had decreased sleep and REM latencies. Epilepsy may affect nocturnal sleep, and the effects of partial and generalized seizure disorders may be different. AEDs may also have differential effects on nighttime sleep. These may prove important in the long-term management of epileptic patients.

Adult↗
PubMed1990

Auditory evoked potentials in narcolepsy and sleep terrors.

Dysfunction of brainstem reticular activating centers has been suggested in some sleep disorders, including narcolepsy and sleep terrors. Previous studies have suggested normal brainstem auditory evoked potentials (BAEPs) in narcolepsy and enhancement of long-latency auditory event-related potentials (ERPs) in sleep deprivation and conditions of pathological somnolence. Sleep terrors have not to date been studied neurophysiologically. We recorded early latency BAEPs and long-latency auditory ERPs in 8 patients with narcolepsy and 5 individuals with sleep terrors, and compared them to 10 normal controls. Narcolepsy patients and controls did not differ significantly in absolute or interpeak latency of BAEPs. Sleep terror patients had significant prolongation relative to controls of III-V and I-V interpeak latencies. The N1, N2, and P3 AEP components were prolonged in latency in narcoleptic patients as compared to controls, while sleep terror patients did not differ from controls. No significant differences in amplitude were found. These findings suggest that a disturbance of integration of brainstem centers subserving wakefulness and sleep may play a role in the disordered arousal of sleep terrors, but suggest no specific abnormality in brainstem function in narcolepsy. The AEP changes in narcolepsy may be a manifestation of pathological sleepiness.

Adolescent↗
PubMed1990

Sleep and sleep deprived EEG in partial and generalized epilepsy.

Sleep and sleep deprivation are often used for EEG activation in epilepsy. We compared postprandial naps and day-long sleep deprived EEGs in 36 patients with generalized seizures, 57 complex partial seizure patients, and 7 individuals with mixed seizure disorders. Ten of 36 generalized seizure patients had normal sleep and sleep deprived EEGs, while both were normal in 16 of 57 partial seizure patients. Both were abnormal in 18 of 36 generalized and 22 of 57 partial epileptics. Seven generalized seizure patients had epileptiform discharges or seizures during afternoon naps but normal sleep deprived EEGs. No partial seizure patients had normal sleep deprived EEGs and abnormal nap, but 29 of 57 had abnormalities or seizures only with sleep deprivation. All 7 mixed seizure patients had abnormal sleep and sleep deprived studies, and 6 had seizures, 4 on both studies. Natural sleep may facilitate the appearance of generalized seizures or epilepti-form discharges, while sleep deprivation may accentuate the yield of EEG abnormality in partial epilepsy. Either is likely to be abnormal in patients with mixed seizures and encephalopathy. Natural sleep and sleep deprived EEGs are an appropriate combination in the evaluation of refractory seizures.

Adolescent↗
PubMed1989

Long-latency auditory event related potentials in migraine.

The pathophysiology of migraine and its associated perceptual symptoms remains controversial. We recorded long-latency auditory event related potentials (AEPs) in 30 unmedicated patients with common migraine, and compared them to 20 controls. 1,000 and 3,000 Hz tones were presented in an 80:20 ratio at 75 dB SL. 200 responses were recorded and replicated from Cz-A1 + A2, with filter band-pass of 1-100 Hz, analysis time of 1,000 ms., and interstimulus interval of 1.1 second. N100, P200, and N200 ERP components did not differ in latency or amplitude between migraine patients and controls. P300 was longer in latency among those with common migraine, and P300 amplitude was significantly reduced (P greater than 0.05). These findings suggest that migraine may have a central mechanism, and that migraineurs may have a difference in task involvement or perception which may influence their clinical course and response to therapy.

Adolescent↗
PubMed1989

Predictive value of electroencephalography for electroconvulsive therapy.

The EEG has been a widely-used screening procedure before ECT. Previous studies have correlated seizures and post-ECT slowing with ECT efficacy. We investigated the utility of pre-ECT EEG in predicting therapeutic response and post-ECT confusion. EEGs were normal in 54 of 100 patients undergoing first courses of ECT for refractory depression. Patterns within the normal range, were present in 26/100 while 2/100 had paroxysmal discharges without clinical evidence of epilepsy. Focal and generalized EEG slowing were each present in 9/100 records. Full recovery occurred after ECT in 66.6 per cent of those with normal pre-ECT records, 61.5 per cent with borderline EEGs, 55.5 per cent of patients with diffuse EEG slowing, and 22.2 of cases with focal slow waves. Of those with EEG slowing 22.2 percent had little or no response to ECT as compared to 19.2 per cent with EEGs within normal limits and 9.3 per cent with normal EEGs. Four of 6 patients with prolonged confusion had normal EEGs, while 1 each had focal and generalized slowing. EEG slowing was related to incomplete ECT response, but not to therapeutic failure or post-ECT confusion. The limited predictive power of pre-ECT EEG may reflect the prevalence of normal or nonspecifically abnormal EEGs in psychiatric patients and the general efficacy of ECT. Other neurophysiologic methods may yield more definitive information about the mechanism and use of ECT.

Affective Disorders, Psychotic↗
PubMed1989

Quantitation of photic driving in dementia with normal EEG.

The EEG is frequently normal when early dementia is clinically suspected. The presence or absence of occipital driving with intermittent photic stimulation is not helpful in detecting cerebral pathology, but quantitation of photic driving was shown to distinguish between dementia and depression in geriatric patients. We quantified photic driving in twenty clinically demented patients without diffuse or focal EEG abnormality, and compared this in 20 age-matched normal controls. Intermittent stimulation at odd-numbered frequencies between 1 and 31 Hz was carried out. The product of frequency of stimulation and duration of driving response was determined, and the incidence of absent, subharmonic and supraharmonic photic driving was determined. The quantitative measure of frequency times following duration was significantly greater in the nondemented individuals than in demented patients with normal EEGs. More nondemented individuals demonstrated supraharmonic and subharmonic responses than did demented patients. The range of normal variability in persistence, duration, and symmetry of photic driving is great, and caution in determining abnormality on this basis is appropriate. Subtle but measurable changes in photic driving may occur early in dementing illnesses, however.

Aged↗
PubMed1989

Ambulatory cassette EEG in epilepsy evaluation.

The economy and effectiveness of 24-hour ambulatory cassette EEG (AEEG) are increasingly recognized. We reviewed 735 AEEGs recorded between 1983 and 1989. These findings suggest that AEEG may confirm the ictal original of attacks in patients with known epilepsy, and may improve the yield of abnormality in epileptics with normal interictal EEG. Focal slowing may be seen less well on AEEG, and the yield of AEEG is low in random sampling of patients with infrequent or nonspecific symptoms.

Ambulatory Care↗
PubMed1989

The effect of exercise on seizure frequency.

The effect of exercise on seizure frequency is uncertain. While some investigators have reported an increase in the normal background frequency of EEGs after exercise, other investigators believe that exercise increases EEG epileptiform activity in the recovery period following exercise. We asked all patients over a two month period at our outpatient Epilepsy Clinic to complete a questionnaire regarding their exercise habits. Those who were not otherwise healthy, were non-compliant with their medications, or whose blood levels were not therapeutic were eliminated from the analysis. Utilizing the complex Chi-square method, it was determined that patients who participated in some form of exercise had significantly fewer seizures than those who did not exercise (p less than 0.05). Conclusions from this brief study indicate the need for a more comprehensive trial, including EEGs, biochemical studies, and fitness evaluations, to determine the effects of an exercise program on seizure frequency.

Adult↗