Huffing and puffing sign in functional axial jerks with secondary gait impairment

Propriospinal myoclonus (PSM) is characterized by predominant axial jerk-like movements. To date, most of the PSM cases reported in the literature are considered to be functional (psychogenic) in origin. The “huffing and puffing sign” is a clinical clue with high diagnostic specificity for a functional etiology in gait disorders. However, this sign has not yet been described in patients with PSM. Here, we report a case of PSM of functional etiology, with coexisting gait disorder and the “huffing and puffing sign.” Our case adds to the list of clinical diagnostic clues that suggest a functional etiology of PSM.