Relationship of cognitive functioning, whole brain volumes, and T2-weighted hyperintensities in neurofibromatosis-1.

Using quantitative magnetic resonance imaging morphometry, we report that the whole brain volumes of patients with neurofibromatosis-1 are significantly 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 neurofibromatosis-1 or to the presence or absence of T2-weighted hyperintensities. No strong relationship emerged between the extent of neurofibromatosis-1-associated impairment of cognitive functions and degree of macrocephaly; however, the macrocephalic neurofibromatosis-1 group did have a significant verbal impairment relative to the nonmacrocephalic neurofibromatosis-1 group in vocabulary (P < .009).