Dysfunctional facial emotional expression and comprehension in a patient with corticobasal degeneration.

Patients with corticobasal degeneration (CBD) frequently develop orofacial apraxia but little is known about CBD's influence on emotional facial processing. We describe a patient who developed a facial apraxia including an impaired ability to voluntarily generate facial expressions with relative sparing of spontaneous emotional faces. Her ability to interpret the facial expressions of others was also severely impaired. Despite these deficits, the patient had normal affect and normal speech, including expressive and receptive emotional prosody. As patients with corticobasal degeneration are known to manifest both orofacial apraxia and visuospatial dysfunction this patient's expressive and receptive deficits may be independent manifestations of the same underlying disease process. Alternatively, these functions may share a common neuroanatomic substrate that degenerates with CBD.