High cognitive function of an ALS patient in the totally locked-in state.

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a motor neuron disease characterized by progressive degeneration of upper and lower motor neurons. Patients with ALS progressively lose their ability to control voluntary movements and occasionally enter the totally locked-in state (TLS), in which they cannot move any part of their bodies including the eyes. In this study, we clarified the preserved abilities and reorganization of the motor system of a 73-year-old patient with ALS in the TLS using optical topography, a recently developed extension of near-infrared spectroscopy. The patient performed four cognitive tasks dichotic listening, covert singing, word fluency, and motor imagery. The bilateral prefrontal and bilateral sensorimotor areas were activated during the two language-related tasks (dichotic listening task and the word fluency), the right prefrontal and sensorimotor areas during the covert singing task, and the right prefrontal and dorsal sensorimotor areas during the motor imagery task. Contralateral sensorimotor activation was not observed in the motor imagery task. These results suggest that cognitive functions can be preserved in ALS in the TLS, with sensorimotor areas playing an important role.