Crossed cerebellar diaschisis in chronic Broca's aphasia.

The cerebellum has anatomical connections to the cerebral cortex, through which it can affect language function. To study these connections, we investigated patients with chronic Broca's aphasia using MRI and single-photon emission computed tomography (SPECT). We selected 15 such patients (9 male, 6 female, aged 17-64 years, mean age 56 years) from 30 chronically aphasic patients. Using the results of SPECT, we divided them into patients with (group 1) and without (group 2) crossed cerebellar diaschisis (CCD). We compared the language function of the two groups. Patients in group 1 showed classical Broca's aphasia, while patients in group 2 showed mainly word-finding difficulty. Patients with CCD hat infarcts involving the lower part of the frontal gyrus but patients without CCD did not, which suggests that this region may have functional and anatomical connections with the cerebellum. Our findings support the notion that the cerebellum contributes to language.