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Biomedical subjects

J K Maxwell

Publications and source records attributed to J K Maxwell.

7 recordsLinked to original sources

Multivariate discriminant function analysis of neurologic, pain, and psychiatric patients with the MMPI.

The ability of the MMPI to classify five well-defined patient groups was investigated (N = 394; control, neurologic, psychiatric, chronic pain, and random). Clinical inspection and discriminant function analyses of basic clinical and research scales could not classify groups correctly, but discriminant function analyses of 37 variables loaded with CNS items (Cripe Neurologic Symptom items) correctly classified the groups with 78% overall accuracy (70% of neurologic, 62% of psychiatric, 81% of pain, 84% of controls, and 100% random). Results indicate that differential diagnosis is not possible with clinical inspection of scales, but complex statistical analysis of the MMPI is potentially useful in diagnosis and decision making. A method for applying the discriminant function analysis to individual cases is provided.

Activities of Daily Living↗

Audiogenic seizure severity and hearing deficits in the genetically epilepsy-prone rat.

Hearing deficits have been observed in rodents that are susceptible to audiogenic seizures (AGS), including the genetically epilepsy-prone rat (GEPR). AGS susceptibility can be induced in normal animals by treatments that damage the cochlea. In this study, we measured the relative degree of hearing loss in animals from the GEPR substrains that exhibit different degrees of AGS severity and examined the relationship between the deficit and the AGS severity. Auditory brain stem response (ABR) thresholds to clicks in the GEPR substrain that exhibits exclusively maximal AGS severity (GEPR-9) were significantly elevated, and latencies for ABR peaks I, III, and IV were significantly increased as compared to normal Sprague-Dawley rats. ABR thresholds for the substrain of GEPRs were even higher than those in the GEPR-9, and ABR waveforms were distorted. ABR peak IV was significantly longer than normal in the GEPR-3 substrain, as were mean interpeak intervals and central conduction times. These data indicate that significant hearing deficits occur in the GEPR-3 substrain. In non-AGS-susceptible progeny of the GEPR-9 [GEPR-0(9)], ABR thresholds were not significantly different from normal. These data along with studies of ABR thresholds in thyroid-deficient rats suggest that an inverted U-shaped relationship exists between hearing deficit and AGS severity. That is, moderate threshold elevations are associated with increasing AGS severity, but when the hearing deficit exceeds a certain level, a decrement in AGS severity occurs.

Acoustic Stimulation↗

Psychosis following styrene exposure: a case report of neuropsychological sequelae.

A patient with a significant history of substance abuse was exposed to styrene and other solvents in the workplace. He became acutely psychotic, experiencing visual hallucinations. The psychosis was controlled with neuroleptic medications and avoidance of solvent exposure, but he continued to show significant deficits in visual-spatial and memory abilities. These deficits cleared with time away from the workplace. The case is of interest in terms of neuropsychological sequelae of solvent exposure and potential interaction of solvents with alcohol and recreational drugs.

Adult↗

PPVT IQ validity in adults: a measure of vocabulary, not of intelligence.

Used partial correlation and multiple regression procedures to test the hypothesis that the PPVT IQ assesses more than vocabulary in adults. Ss were 84 inpatients from psychiatry and neurology wards. The relationships between the PPVT IQ and other measures of vocabulary, intelligence, memory, visual-motor speed and education were examined in the statistical analyses. Although these variables have significant simple correlations with the PPVT IQ, the multivariate analyses show that the Vocabulary Subtest of the WAIS-R is the only important variable. No other variable or variable combinations are able to account for further PPVT IQ variance after the effect of the Vocabulary Subtest is removed. The results support the use of the PPVT as a test of adult vocabulary, but not adult intelligence, and suggest that the PPVT may be useful as part of language assessment in patients with expressive language disorders.

Adult↗

Fingertip number-writing errors by psychiatric patients.

Records from 495 psychiatric patients from two neuropsychology laboratories indicated the Fingertip Number Writing test shows a significant and reliable left-hand advantage within and between laboratories. While the left-hand advantage may reflect a right-hemisphere superiority for tactile-spatial processing, it is not possible to distinguish between right hemispheric functional superiority and practice effects between hands because the standard fingertip writing task always starts with the right hand.

Dominance, Cerebral↗

Asymmetric cognitive function in anorexia nervosa.

Three anorexics, one at normal weight, were examined, with a neuropsychological battery including the Halstead-Reitan tests. Their data were contrasted with that of 24 psychiatric controls matched for age, sex and IQ. Individually and as a group the anorexics showed above average verbal/academic scores and impaired spatial skills, whereas visual-motor and problem solving skills were equivalent to controls. Somatosensory recognition was impaired bilaterally in all three patients, and motor skills were low in the two emaciated patients. Other sensory tests and intermanual comparisons of sensory and motor skills were not impaired relative to controls. The findings suggest that a spatial reasoning deficit may be a predisposing or maintaining factor in this disorder. High verbal skills, in contrast, may reflect substantial left hemisphere contributions to the anorexic's cognitive style.

Adult↗