SICKLE CELL DISEASE: A NEUROPSYCHOLOGICAL INVESTIGATION (ADOLESCENTS, NEUROPATHY, STROKE, COGNITION, CHRONIC)

Abstract

This study was undertaken to determine the extent to which adolescents with sickle cell disease, without overt evidence of central nervous system damage as that caused by stroke, exhibit subtle aberrations of functioning discernible upon neuropsychological examination. Testing included assessment of fine motor coordination and control, somatosensory perception, visuospatial-visuomotor and perceptual-motor skills, attentional capacity and short term memory. Further, lateralized dysfunctions were ascertained based upon a comparison of the data with correlational research findings and neuroanatomical localization studies.;Twenty-four adolescent (x age = 17.5) with sickle cell disease and 18 control subjects (x age = 17.1) selected through a quota sampling technique, were assessed with the neuropsychological battery including tests of: (1) Rapid Alternating Movements, (2) Finger Agnosia, (3) Graphesthesia, (4) Motor-overflow, or choreiform movements, (5) the Benton Visual Retention Test, Administration C & D, (6) the Raven's Colored Progressive Matrices and, (7) the Digit Span Subtests from the Wechsler Batteries.;Differences between groups relative to test performance were analyzed employing two techniques. Statistical analysis utilizing Pearson's r and Chi Square (with Yates correction) has been accomplished. The differences between groups, using cutting score criteria and standard scores, is further represented in a percentile-ratio format. In this way the data can be seen relative to the direction of error or pathological performance, by comparison of ratios, cluster scores and trends in statistically derived significance levels.;Results suggest an increased prevalence of minimal neurological and cognitive deficits, particularly upon tasks known to be effected by right hemisphere damage or dysfunction. These included tests of: fine motor coordination and control (rapid alternating movements), tactile sensory perception (finger agnosia, graphesthesia), visual perception and visual-motor integration (Benton and Ravens Tests), and tasks accessing short term memory function (digit span-backward). Those tasks known to be most sensitive to left hemispheric dysfunction (digits forward, Benton Memory) either failed to differentiate the groups, or were performed with greater error by the control group.;These data suggest that adolescents with sickle cell disease who have not had stroke or overt CNS damage are at a greater risk for abnormal neurological and cognitive functioning. The exact mechanism responsible for such effects remain unknown, yet may be primarily or secondarily related to the course of sickle cell disease.;These findings are of particular interest relative to the impact of the disease process upon the development of the central nervous system and points to the need for and direction of further research.