Mutism developing after bilateral thalamo-capsular lesions by neuro-Behçet disease.

We described a 44-year old right-handed man showing mutism, left hemiplegia and pseudobulbar palsy after CT and MRI documented bilateral thalamo-capsular lesions by neuro-Behçet disease. Single photon emission tomography (SPECT) and Xenon CT revealed hypoperfusion of the bilateral frontal lobes. The pathophysiological mechanism of mutism was discussed and we postulate that mutism might occur as the result of frontal lobe dysfunction due to the disconnection of thalamocortical fiber from thalamus to frontal cortex and that it could be interpreted as an incomplete form of akinetic mutism.