Flail‐arm variant of amyotrophic lateral sclerosis in a Spanish soccer player

Sir, A number of studies suggest a high risk of ALS among Italian professional soccer players [1], with 10-fold increased mortality rate in prospective epidemiological data [2]. During the last 6 years, an annual mean of 1516 professional football players (range, 1311–1800; 164.5 SD) have been licensed in Spain [3]. We report the case of a soccer player who developed the Flailarm variant of ALS at the age of 33, without prominent bulbar symptoms. A 34-year-old white man consulted with progressive weakness and atrophy in both upper limbs. No family history of neuromuscular disease was recorded. He played as a centre-back in the Spanish Premier League for 9 years (about 45 games a year), but a serious injury to his left knee forced him to retire at the age of 28. He had never suffered a significant head injury, but used to clear the ball by violent twisting of the neck. He did report taking dietary supplements (not specified), and he denied having taken illegal drugs. Eighteen months before consultation, he noticed difficulty when lifting objects overhead because of proximal weakness in both upper limbs, more so on the right side. Over the next 15 months, the weakness spread distally to both hands and was associated with severe muscle wasting. In the last 3 months, he had noticed a mild speech difficulty with no choking spells. Both upper limbs were observed to swing loosely in internal rotation alongside the trunk, with severe bilateral muscular atrophy and hypotonia, extending from the shoulder girdle to the intrinsic muscles of the hand. The patient was able to walk with slight bilateral steppage gait; otherwise, muscular power in the lower limbs was nearly normal with no evident amyotrophy. Fasciculations were observed in all four limbs and tongue. Mild dysarthria for lingual consonants was present. Deep tendon reflexes in the four limbs and the jaw reflex were hyperactive. Bilateral extensor plantar responses were elicited. There were no cognitive, oculomotor or sensory impairments. He scored 33 in the ALSFRS-R scale. Magnetic resonance imaging of the brain, cervical and dorsal spinal cord was normal. Electromyography revealed diffuse chronic neurogenical abnormalities including profuse spontaneous activity with fibrillation and fasciculation potentials, as well as positive sharp waves. Electroneurography ruled out the presence of motor conduction blocks in the upper limbs, with normal sensory and motor conduction velocity. Muscle enzymes and thyroid function were normal. Hexosaminidase A deficiency, serum paraproteins and heavy metals were ruled out. Our patient met El Escorial diagnostic criteria for definite ALS [4]. During the first 15 months, symptoms were limited to both upper limbs, consistent with the flailarm variant of ALS [5,6]. Age at onset in the flail-arm variant is similar to that of conventional ALS, with a male preponderance, although survival is about 5 years above average [7]. Our patient had an early onset (age 33), and is similar to that of soccer players with ALS in Italy, about 20 years earlier than average. Bulbar onset was relatively common among Italian soccer players [1], leading to the proposal that repetitive microtrauma to the head might play a role in the disease [8]. Constant clearance of the ball by violent twisting of the neck in our patient could have resulted in repeated microtrauma to the cervical cord leading to a flail-arm variant.