Relationship of cognitive functioning, whole brain volumes, and T-2-weighted hyperintensities in neurofibromatosis-1

Using quantitative magnetic resonance imaging morphometry, we report that t he whole brain volumes of patients with neurofibromatosis-1 are significant ly larger than normal, confirm the prevalence of macrocephaly as about 50%, and report that macrocephaly in patients with neurofibromatosis-1 does not appear to be related to the familial or sporadic origin of the neurofibrom atosis-1 or to the presence or absence of T-2-weighted hyperintensities. No strong relationship emerged between the extent of neurofibromatosis-1-asso ciated impairment of cognitive functions and degree of macrocephaly; howeve r, the macrocephalic neurofibromatosis-1 group did have a significant verba l impairment relative to the nonmacrocephalic neurofibromatosis-1 group in vocabulary (P < .009).