ABSTRACT
Many ALS patients experience deterioration of voluntary motor function in all four limbs and speech, followed by deterioration of voluntary motor function in facial muscles, so that nonverbal communication also becomes difficult. ALS can be divided into upper limb, lower limb, and bulbar types [6], according to the site of onset of motor function deterioration. Nevertheless, in each type, motor function deteriorates over the entire body as the disease progresses. In upper limb onset ALS, communication is impaired by the difficulty of voluntary movement of the shoulder, elbow, hand, and finger joints, and so it becomes difficult to write or input text using a mouse or keyboard. Nonlinguistic communication such as arm gestures is also impaired. In lower limb onset ALS, voluntary movement of the hips, knees, and ankles is impaired, and so it becomes difficult to move towards people for communication or move to where communication devices are located. Bulbar onset ALS impairs voluntary contraction of the muscles used for speech, swallowing, and facial expressions, and so linguistic communication such as conversation and nonlinguistic communication through facial expression become difficult.
