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Biomedical subjects

M E Drake

Publications and source records attributed to M E Drake.

At least 73 records · Page 4Linked to original sources
PubMed1988

Brain-stem auditory-evoked potentials in spasmodic torticollis.

The pathophysiology of idiopathic spasmodic torticollis is uncertain. Cerebral, basal ganglia, brain-stem, and cervicomedullary lesions have been implicated. Some investigators have found evoked-potential abnormalities, while others have not. We recorded brain-stem auditory-evoked potentials in six patients with otherwise normal result of examinations and laboratory studies. Brain-stem auditory-evoked potentials were recorded from Cz-A1 and Cz-A2 with rarefaction clicks delivered at 11.1/s and 70 dB above sensory threshold with 40-dB contralateral masking. Analysis time was 10 ms, filter bandpass was 150 to 3000 Hz, and 4000 averages were replicated. Patients and age-matched controls were compared by Student's t test. One patient had I-III and I-V interpeak latencies (IPLs) beyond clinical norms (99% tolerance limit). Mean IPLs ipsilateral to torticollis were 2.32 +/- 0.2 (I-III), 1.96 +/- 0.4 (III-V), and 4.16 +/- 0.3 (I-V). Contralateral IPLs were 2.0 +/- 0.2 (I-III), 2.0 +/- 0.2 (III-V), and 3.9 +/- 0.5 (I-V). Control values were 2.04 +/- 0.2 (I-III), 1.86 +/- 0.2 (III-V), and 3.86 +/- 0.4 (I-V). Absolute latencies, V/I amplitude ratios, and III-V IPLs did not differ significantly between patients and controls, nor did IPLs contralateral to torticollis. Ipsilateral I-III and I-V IPLs were greater in patients than in controls. These findings are consistent with those of some clinical reports and with experimental evidence that brain-stem lesions produce torticollis. They imply brain-stem dysfunction ipsilateral to head deviation in at least some patients with torticollis.

Brain Stem↗
PubMed1988

Effects of seizure type and waveform abnormality on memory and attention.

Deficits in memory, learning, and attention were examined in a sample of 57 patients admitted for investigation of intractable seizure disorder. The patients were grouped according to seizure type and nature of electroencephalographic abnormality. Patients with complex partial seizures were impaired in comparison with controls. Patients with spike-and-wave abnormalities were more impaired on some tests, while those with slow-wave abnormalities were impaired on other tests. These results suggest that, contrary to previous studies, patients with complex partial seizures have greater deficits than other seizure types in some areas of cognitive function.

Attention↗
PubMed1988

Evoked potentials in chronic inflammatory demyelinating polyneuropathy.

Eighteen patients with chronic inflammatory demyelinating polyneuropathy were studied with evoked potentials to assess for evidence of central nervous system demyelination. Both visual and brain-stem auditory evoked responses were obtained, and the results were compared with magnetic resonance imaging (MRI). An evoked potential was abnormal in nine of 18 patients, five of whom had central nervous system evidence of demyelination by MRI. Evoked potentials identified four patients with probable anterior optic pathway involvement that was not demonstrable by MRI. These findings continue to support that chronic inflammatory demyelinating polyneuropathy is associated with a central demyelinating disorder and more importantly emphasize the possibility of a common pathogenic mechanism in central and peripheral nerve demyelination.

Brain Stem↗
PubMed1988

Auditory event related potentials in violent and nonviolent prisoners.

The neurophysiologic substrates of violence and aggression have been extensively studied. Although the EEG is often normal in violent persons any abnormalities are generally nonspecific in nature. Evoked potentials have been infrequently used to study such behavior disorders. Long latency auditory event-related potentials (AEPs) were studied in prison inmates incarcerated for unmotivated violent crimes or violence during the commission of other crimes, and in prisoners jailed for non-violent offenses. Habitually violent inmates were compared with an equal number of non-violent prisoners and neurologically and audiologically intact controls. AEPs were recorded to an "oddball" paradigm from vertex and left and right temporal electrodes. None of the prisoners had latencies more than 3 standard deviations beyond the normal group mean. N1 and P2 components were longer in latency and lower in amplitude in prisoners than in controls, but this was not statistically significant. Violent and non-violent individuals did not differ in these measures. P3 was significantly prolonged in latency in violent inmates, but not in those who had committed a violent act. All components were longer in latency on the right in violent prisoners, while amplitudes were lower but not significantly so. This asymmetry was not present in non-violent prisoners or control subjects. Caution is needed in identifying differences between criminals and the general population, and in seeking markers of violent behavior.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Restless legs with antiepileptic drug therapy.

The restless legs syndrome is generally benign but is occasionally associated with anemia, metabolic disorder, or polyneuropathy. Leg restlessness with disruptive nocturnal myoclonus has been described as a sleep disorder. We report two patients with complex partial and secondarily generalized seizures, who developed restless legs while taking methsuximide and phenytoin. They had no evidence of metabolic disturbance or neuromuscular disease, although one patient had fragmented sleep and disruptive myoclonus on polysomnography, and leg restlessness subsided with change of antiepileptic drugs. These symptoms could reflect transient alteration in peripheral nerve function not evident by examination or electrophysiologic studies, sleep disturbance by antiepileptic drugs or the effects of temporal lobe seizure foci on perception of the physiologic state of nerves and muscles.

Adult↗
PubMed1988

Lupus anticoagulant and lacunar infarctions.

Lupus anticoagulant is more often associated with thromboembolism than hemorrhage. We have observed two cases of lupus anticoagulant associated with basal ganglion lacunar infarction, causing contralateral choreoathetosis. One patient had no evidence of lupus or other etiology, and responded to antiplatelet therapy, while the other was found to have systemic lupus erythematosus with nephritis and was successfully treated with steroids. The effects of lupus anticoagulant on platelet prostacyclin receptors or prostacyclin production, or its effect on cerebral vessels may permit small-vessel occlusion and lacunar infarction in susceptible patients.

Adult↗
PubMed1988

EEG frequency analysis in conversion and somatoform disorder.

Patients with "hysterical" neurologic symptoms have long puzzled neurologists and psychiatrists. "Hysteria" has recently been subdivided into conversion and somatoform disorder. We applied computerized EEG frequency analysis to 10 patients with diagnosed conversion disorder, 10 somatoform disorder patients, and 10 control subjects. One minute EEG samples composed of 4 sec epochs were recorded from left frontal (F7-C3), right frontal (F8-C4), left posterior (T5-01) and right posterior (T6-02) derivations. Spectral power was calculated for 4 bands (0.25-4HZ, 4.25-8Hz, 8.25-13Hz, and 13.25-30Hz), and for the full frequency range. Low (0.25-8Hz) and high (8.25-30Hz) frequency bands were compared to determine high/low power ratios on the left and right (PHLL) and (PHLR), ratios of left/right front (PLRF) and posterior (PLRP) power, mean alpha frequency deviation frontally (FLRF) and posteriorly (FLRP), and mobility of left and right frontal power (MOLF and MORF). No significant differences were found between conversion disorder patients and controls in PHLL, PHLR, PLRP, and MORF. PLRF, FLRF and MOLF differed significantly between patients and controls. Power and frequency ratios of right frontal mobilities suggested a decrease in high frequency power, reduction in mean alpha frequency, and lower predominant frequency in the right frontal area in somatoform disorder patients as compared to controls, but significance was not reached. Somatoform and conversion disorder patients differed significantly in these spectral measures. These observations suggest that the two "hysterical" disorders may have distinct pathophysiology, and may be due to eventually identifiable cerebral dysfunction in some cases.

Adult↗
PubMed1988

EEG evidence of epileptiform paroxysms in rapid cycling bipolar patients.

Electroencephalographic (EEG) abnormalities have been described in patients with mood disorders. In an effort to determine if rapid cycling bipolar affective disorder patients may demonstrate more prevalent EEG paroxysmal activity than patients with non-rapid cycling mood disorders, we studied five consecutively identified bipolar patients who cycled at least four times a year. They were compared with 25 consecutive affective disorder patients who received an EEG before electroconvulsive therapy. Three of the five rapid cycling patients had bitemporal paroxysmal sharp waves as demonstrated by EEG but no psychomotor evidence of epilepsy. None of the 25 comparison patients had EEG abnormalities. Four of the five rapid cyclers reported a family history of affective disorder, including the three who had paroxysms.

Adolescent↗
PubMed1987

Forced normalization. Acute psychosis after seizure control in seven patients.

An antagonistic relationship between psychosis and seizures has been described in some patients and is sometimes termed "forced normalization." We saw seven epileptic patients without a previous psychiatric history, who developed acute psychotic states on establishment of seizure control and normalization of previously abnormal electroencephalograms with frank epileptiform activity. A possible hypothetical relationship between psychosis and epilepsy regarding the mesolimbic dopaminergic system and kindling of this system with epileptic discharge in temporal-limbic circuits could induce a florid psychotic state in some patients. This biochemical relationship to schizophrenia with heightened dopamine activity would also easily explain the amelioration of acute psychotic activity in our seven patients with neuroleptic agents and their antagonism of this increased dopaminergic outflow state.

Adult↗
PubMed1987

Evoked potentials and EEG in multiple sclerosis.

Thirteen patients with clinically definite multiple sclerosis (MS) were studied with electroencephalogram (EEG), magnetic resonance imaging (MRI), evoked potentials and cerebrospinal fluid (CSF) analysis. We attempted to correlate the findings with physical disability as defined by Kurtzke score and presence of dementia or seizures. More severe plaque disease on MRI and increased physical disability correlated significantly with abnormality on brain-stem auditory evoked potentials (BAEPs) while visual evoked potential (VEP) abnormality correlated only with MRI findings. No such correlation was found with the EEG. The close relationship between BAEP and MRI abnormalities probably reflects frequent involvement of brain-stem corticospinal pathways.

Adult↗
PubMed1987

Postictal Capgras syndrome.

The Capgras syndrome of delusions that familiar persons are being impersonated by identical doubles has occasionally been associated with cerebral disease, often of the nondominant hemisphere. A patient with chronic right cerebral hemisphere dysfunction and complex partial seizures of right temporal origin manifested the Capgras syndrome in the postictal state, and the delusions ceased with optimal seizure control. The delusions could result from postictal disinhibition of dominant hemisphere recognition functions, or from dysfunction of nondominant hemisphere centers involved in perceptual integration.

Adult↗