Spinal and bulbar muscular atrophy (SBMA), also known as
Kennedy's disease, is a rare, slowly progressive, incurable, and
hereditary neurodegenerative disease caused by the
testosterone-dependent accumulation of pathogenic
polyglutamine-expanded
androgen receptor protein. After extensive review, two treatments for SBMA have recently been approved in Japan; this decision was based on the results of randomized controlled trials: First, anti-
androgen therapy using
leuprorelin acetate (
leuprorelin), a disease-modifying drug that can inhibit the progression of
dysphagia but has not yet been proved to improve gait function; second, cybernic treatment with a wearable cyborg hybrid assistive limb (HAL®) (Cyberdyne Inc. Tsukuba, Japan). The HAL is an innovative walking exercise system that has been shown to significantly improve gait function in eight
neuromuscular diseases without reduction in muscle function, including SBMA. It is possible that the combination of these two approaches might yield better outcomes. However, the long-term effects of such a combined approach have yet to be clinically evaluated. Here, we describe the case of a 39-year-old male with SBMA who commenced anti-
androgen therapy with
leuprorelin 1 year previously; this was followed by cybernic treatment with HAL. The duration of walking exercise with HAL was 20-30 min a day in one session. Over 2 weeks, the patient underwent nine sessions (one course). The efficacy of HAL was evaluated by gait function tests before and after one course of cybernic treatment. Then,
leuprorelin treatment was combined with cybernic sessions every 2 months for 2 years (13 courses in total). Walking ability, as evaluated by the 2-min walk test, improved by 20.3% in the first course and peaked 10 months after the commencement of combined
therapy (a 59.0% improvement). Walking function was maintained throughout the period. Generally, SBMA is characterized by moderately increased serum levels of
creatine kinase (CK), reflecting neuromuscular damage; interestingly, the patient's CK levels decreased dramatically with combined
therapy, indicating remarkable functional improvement. Long-term combined
therapy improved the patient's gait function with a steady reduction in CK levels. The combination of
leuprorelin with cybernic treatment can, therefore, improve and maintain gait function without damaging the motor unit and may also suppress
disease progression.