Neurofibromatosis and psychological processes.

A minimal degree of mental handicap is commonly seen in neurofibromatosis (NF). Despite the prevalence, little is known about the nature of the mental handicap. In this study, schoolchildren with NF and unaffected siblings were studied clinically and given a series of psychological tests. The psychological battery consisted of standardized tests of intelligence and cognitive processing, laboratory tests of cognitive processing, and personality and mood questionnaires. Clinical data included a medical and family history, results of physical, audiological, and ophthalmological examinations, EEG, tissue biopsy when necessary, and (in NF individuals) a CT scan. Results demonstrate slightly deficient cognitive processing in the NF individuals, particularly in terms of visual-spatial integration. These deficits are related to age-independent severity with more severely affected individuals exhibiting more severe deficits. The findings are discussed in terms of their diagnostic and prescriptive implications.