Creutzfeldt-Jakob disease (CJD) is an ultimately fatal, neurodegenerative disease caused by misfolded prion protein aggregation and accumulation. The development of amyotrophic features has been described in CJD, though rarely as an early or prominent feature. Consequently, the significance of amyotrophy in prion disease etiology remains unclear.

Our patient, a healthy 70-year-old French/Algerian man, presented to our hospital following a work-related fall and was admitted with lower limb skeletal muscle atrophy and fasciculations; the fasciculations progressed to involve the trunk, upper limbs and face. Within days, he developed evidence of a progressive ascending neurological syndrome and subsequent brain involvement with supranuclear palsy of upgaze, catalepsy and death 36 days after symptom onset. Amyotrophy remained the principle feature of his disease. Dementia started to develop within 10 days of the onset of his amyotrophy. Prion disease was confirmed at postmortem.

Our observations suggest an unusual form of prion disease with prominent early involvement of anterior horn cells, ascending prion propagation in the central nervous system and a grave prognosis.