FRONTAL-LOBE VOLUME IN PATIENTS WITH HUNTINGTONS-DISEASE

Neuropathologic and neuroimaging studies have suggested that frontal l obes are affected in Huntington's disease (HD), and that atrophy in th is region may be associated with some of the cognitive impairment and clinical decline observed in patients with HD. We measured gray and wh ite matter volumes within the frontal lobes on MRI for 20 patients wit h HD (10 mildly affected and 10 moderately affected) and 20 age-and se x-matched control subjects. We also correlated frontal lobe measuremen ts with measures of symptom severity and cognitive function. Patients who were mildly affected had frontal lobe volumes (both gray and white matter) essentially identical to those of control subjects, despite c learly abnormal basal ganglia. Patients who were moderately affected d emonstrated significant reductions in total frontal lobe volume (17%) and frontal white matter volume (28%). Frontal lobe white matter volum e reductions, but not total frontal lobe volume reductions, were dispr oportionately greater than overall brain volume reductions (17%). Fron tal lobe volume correlated with symptom severity and general cognitive function, but these correlations did not remain significant after tak ing into account total brain volume. We conclude that cognitive impair ment and symptom severity are associated with frontal lobe atrophy, bu t this association is not specific to the frontal lobes. Frontal lobe atrophy (like total brain atrophy) occurs in later stages of increasin g HD symptom severity and this atrophy primarily involves white matter .