Chronic cerebrospinal fluid leak can cause amyotrophic lateral sclerosis mimic

CASE The patient is a 50-year-old male who has experienced chronic, progressive difficulty raising his left upper limb since the age of 13 and similar symptoms in his right upper limb since the age of 48. The manual muscle strength test results indicated that the patient had decreased strength in several muscle groups, including the infraspinatus (3/2), deltoid (4−/2), biceps brachii (5/3), triceps brachii (5/4), and serratus anterior (5/4+) with proximal muscle predominance. CONFLICT OF INTEREST STATEMENT The authors have stated explicitly that there are no conflicts of interest in connection with this article.