Neurofibromatosis type 1: motor and cognitive function and T2-weighted MRI hyperintensities.

BACKGROUND

Cognitive impairment and fine motor deficits are frequent manifestations in patients with neurofibromatosis type 1 (NF1). More than 50% of patients with NF1 show focal areas of high signal intensity (T2H) on T2-weighted MRI of the brain. It has been hypothesized that T2H may be associated with the cognitive and motor problems.

METHODS

The authors investigated 100 patients with NF1 and 100 healthy control subjects matched for age, sex, and socioeconomic status for their IQ (Wechsler Intelligence Scale for Children-Revised [WISC-R] and Wechsler Adult Intelligence Scale-Revised [WAIS-R]), fine motor abilities (Motorische Leistungs-Serie [motor performance task]), and T2H (MRI).

RESULTS

As a group, the 100 patients performed within normal limits of WISC-R and WAIS-R scores. However, the scores for the NF1 patients with normal MRI were at the mean, whereas those for the patients who had T2H (n = 58) were significantly depressed. On measures of fine motor skills, patients with T2H performed poorer than patients with normal MRI.

CONCLUSION

Hyperintensities on T2-weighted MRI represent a biological marker for impaired cognitive and fine motor performance in patients with NF1.