Search PubMed⌕ Search

Biomedical subjects

M E Drake

Publications and source records attributed to M E Drake.

133 records · Page 8Linked to original sources
PubMedDate not supplied

The association of motor neuron disease and Alzheimer-type dementia.

An elderly woman is described who developed senile dementia of the Alzheimer type, followed within eight months by classical and electromyographic features of sporadic motor neuron disease. Although amyotrophic lateral sclerosis is generally believed to affect the voluntary motor system and spare intellectual function, with the exception of certain familial forms and geographic isolates in the Pacific, pathological involvement of the cerebral cortex and posterior columns has often been demonstrated. A small number of cases of concomitant amyotrophic lateral sclerosis have been reported, but an association has not thereby been proven. With the incidence of dementia increasing, it is possible that epidemiologic studies may show an increase in the incidence of motor neuron disease, and thereby suggest an association. A unitary hypothesis for causation of amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer's disease has been proposed. Closer investigation of patients with motor neuron disease for dementia, and inquiry into the incidence of motor dysfunction in demented patients, may yield evidence in support of such a hypothesis.

Aged↗
PubMedDate not supplied

WAIS-R factor structure in epileptic patients.

The Wechsler Adult Intelligence Scale--Revised (WAIS-R), the newest version of the Wechsler Scales, has had several factor analytic studies, but none have been done in a sample of seizure-disorder patients. The factor structure of the WAIS-R was examined in this study in a sample of 107 patients with various seizure disorders. The results of this study revealed the 3-factor solution, as has been reported in many previous studies. The most notable difference was the relatively greater prominence of the Freedom from Distractibility factor. These results are consistent with studies of the factor structure of previous editions of the Wechsler Scales in samples of epileptic patients. The relative prominence of the Distractibility factor could suggest that attentional factors are a more important influence on performance than in other patient groups. Further studies are needed to clarify the effect of various seizure-related variables on patterns of intelligence.

Adolescent↗
PubMedDate not supplied

Comparison of a noninstrumented immunoassay for carbamazepine to high performance liquid chromatography and fluorescence polarization immunoassay.

The accuracy, precision, and potential clinical utility of a new whole blood, noninstrumented immunochromatographic assay (AccuLevel) for carbamazepine (CBZ) was evaluated in a multicenter trial including 100 pediatric and 205 adult patients. The AccuLevel assay, a fluorescence polarization immunoassay (FPIA), and high-performance liquid chromatography (HPLC) were used to determine CBZ concentration in samples from 111 female and 194 male patients aged 2-72 years (median 25 years). Mean +/- SD plasma CBZ concentrations in all patients were 7.4 +/- 3.0 micrograms/ml with the AccuLevel assay and 7.5 +/- 2.9 micrograms/ml with FPIA. In 204 patients, the mean concentration determined by the HPLC assay was 7.7 +/- 3.0 micrograms/ml, whereas concentrations determined by the AccuLevel and FPIA assays were 8.0 +/- 3.1 and 8.1 +/- 3.1 micrograms/ml, respectively. Concentrations determined by the AccuLevel and FPIA assays were significantly higher than those quantified by HPLC (p less than 0.05), but not different from each other. In addition, the AccuLevel assay was highly correlated with FPIA (r = 0.97) and HPLC (r = 0.98). Coefficients of variation for the AccuLevel assay at 8 micrograms/ml ranged from 6.8 to 7.5% for the three institutions. We conclude that the AccuLevel assay is a simple, reliable method for determining CBZ concentration in a small volume of whole blood and is an acceptable alternative for assessment of CBZ therapy and individualization of CBZ dosage in the physician's office or emergency room.

Adolescent↗
PubMedDate not supplied

Central conduction time in progressive supranuclear palsy.

Progressive nuclear palsy (PSP) is a parkinson-like extrapyramidal disorder with pathological evidence of brain stem demyelination. We studied brain stem auditory (BAEP) and somatosensory (SSEP) evoked potentials in 8 patients with progressive supra-nuclear palsy to look for evidence of such central demyelination. We found minor alterations in BAEPs and frequently abnormal SSEPs, suggestive of brain stem white matter involvement in this disorder. Evoked potentials may assist in the differentiation of PSP from other parkinsonian conditions.

Aged↗
PubMedDate not supplied

Visual and auditory evoked potentials in migraine.

We recorded visual (VEP) and brainstem auditory (BAEP) evoked potentials in 50 patients with clinically diagnosed common migraine attended by visual obscuration or sensory symptoms but no neurologic deficit. VEPs were recorded from Oz, 01, and 02 referenced to Fz, with replication of 200 repetitions of 1.88 per second checkerboard stimuli subtending a 56 minute retinal arc. Analysis time was 250 ms., and filter band pass was 1-250 Hz. BAEPs utilized rarefaction stimulation at 70 dB SL, with 150-3,000 Hz filter band pass and 10 ms. analysis time. Two thousand averages were recorded and replicated from Cz-A1 and Cz-A2. VEP N1, P1 and N2 latencies were longer in migraine patients than in controls, and VEP amplitudes were minimally greater. No significant differences were found between patients and controls, however. BAEP I-V and III-V interpeak latencies were significantly prolonged in migraine patients, and the degree of prolongation was greater on the left. Neither VEPs nor BAEPs exceeded clinical norms in migraine patients. VEPs and BAEPs are likely to add little to the clinical assessment of headache patients. BAEP differences may indicate dysfunction of brainstem centers, possibly related to endorphin or serotonin neurotransmission, and possibly related to the pathogenesis of migraine. The left sided asymmetry has been described previously and is of uncertain significance, but may also support a central mechanism for migraine.

Adolescent↗
PubMedDate not supplied

Effect of anti-epileptic drug monotherapy and polypharmacy on visual and auditory evoked potentials.

Previous reports have suggested that some anticonvulsants may prolong somatosensory and auditory evoked potential latencies. We compared pattern-reversal visual and brainstem auditory evoked potentials in normal controls, patients on monotherapy, and patients taking polypharmacy. Visual evoked potential amplitudes were less in seizure patients, and P1 latencies were longer in epileptics on polypharmacy than controls. Absolute latencies of brainstem auditory evoked potentials were longer in polypharmacy patients than in controls or monotherapy patients. I-III, III-V, and I-V interpeak latencies were greater in polypharmacy patients than in those on monotherapy or controls. These findings suggest that anticonvulsants may affect conduction along visual and auditory pathways, and that antiepileptic drug polypharmacy and monotherapy may differ in their effects.

Adolescent↗