Flail arm syndrome with several issues related to the diagnostic process

Abstract

Flail arm syndrome (FAS) has a similar clinical course 1 and pathological findings as amyotrophic lateral sclerosis (ALS). 2 It is important to distinguish the two diseases because FAS patients have significantly better survival rates compared with other typical ALS variants. 1,3 We report a FAS patient confirmed by clinical and electrophysiological findings based on review of literatures. We show the findings of polysomnography (PSG) in patient with FAS. We suggest that several issues related to the diagnostic process needed to be addressed. CASEA 50-year-old male presented with slowly progressive weakness and muscle wasting in his arms about two years ago. At the time of the first manifestation, weakness was noted in the right proximal arm accompanied by atrophy and identical symptoms occurred in the left arm after a one year.He had no remarkable medical history except for hypertension and there was no related family history. In neurological examination, bilateral weakness of the arms was scored as Medical Research Council grade I proximally and grade III in the distal muscles symmetrically, combined with muscle atrophy in the upper limb girdles. Both acromion processes of the scapular bone protruded beneath the skin. Both of his arms, forearms and hands were pronated. Fasciculation were absent in his all limbs and tongue. Sensory examination was normal Flail arm syndrome (FAS), known as one of the atypical amyotrophic lateral sclerosis (ALS) variants, has a similar clinical course and pathologic findings as ALS. Therefore it is difficult to differentiate between ALS and FAS at a glance. There are few reports involving individual analysis of FAS patients to date. The findings of polysomnography (PSG) in patient with FAS are not well known. We report a male FAS patient with review of literatures and several issues related to the diagnostic process.