Atypical progression of motor symptoms in facio-scapulo-humeral dystrophy: clinical worsening or overlap?

Facio-scapulo-humeral dystrophy (FSHD) is a common muscular dystrophy featuring progressive weakness, mostly involving facial muscles and the scapular cingulum. FSHD is an autosomal-dominant inherited disease driven by the contraction of the D4Z4 region of chromosome 4. Patients with FSHD have a high life expectancy, about 20% of FSHD subjects need wheelchairs in their 50s, and extramuscular involvement is rare, however, no epidemiological studies have been carried out on this data.Our case describes a man affected by FSHD who, in his 60s, developed atypical Parkinsonism diagnosed as progressive supranuclear palsy (PSP).FSHD symptoms can hide other neuromuscular diseases developed on ageing. This case highlights the importance of considering possible overlaps with other neurodegenerative diseases.