[Capsular pseudobulbar mutism in a patient of lacunar state]

A patient of mutism with pseudobulbar palsy and frontal lobe syndrome resulting from lacunar state was reported. The patient, a 64-year-old man, was admitted to Gifu University Hospital because of a decrease in spontaneous activity, lack of volition and anorexia. The CT scan, performed on July 29, 1987, demonstrated lacune in the right internal capsule (IC), periventricular lucency especially around the anterior horn of lateral ventricles, and ventricular dilatation. He was transferred to a medical ward because of repeated aspiration pneumonia. Neurological examination revealed mutism, pseudobulbar palsy, and frontal lobe signs. The CT scan, performed on March 30 1988, demonstrated the newly developed lacune in the left IC. The MRI also showed two coinciding lacunes, one in the genu of the right IC and the other in the anterior limb of the left IC. The SPECT with 123I iodoamphetamine showed decreased blood supply predominantly to the frontal lobes. A mechanism by which the mutism occurs is discussed from two points of view, pseudobulbar palsy and frontal lobe syndrome. He developed initially frontal lobe syndrome in which paucity of spontaneous speech was noted. The CT scan at that time demonstrated lacune in the right IC. About eight months later when he became mute, the CT scan showed lacunes in bilateral ICs without any other low density areas in frontal language areas such as Broca's area, subcortical area and supplementary motor area. As the MRI showed that the right lacune was in the genu but the left lacune was in the anterior limb of IC, the left cortico-bulbar tract was thought to be not directly involved. The SPECT showed decreased blood supply predominantly to the frontal lobes. Although dysphagia improved, mutism did not improve at all. Therefore it is postulated that both pseudobulbar palsy and frontal lobe dysfunction might play a role in producing the mutism of this patient.