Familial Creutzfeldt-Jakob disease with E200K mutation presenting with neurosensorial hypoacusis.

Creutzfeldt-Jakob disease (CJD) is characterised by rapidly progressive dementia, myoclonus, ataxia, visual disturbances and motor dysfunction. Most of the cases are sporadic. Only 10% to 15% are familial, and the most frequent point mutation is E200K. A 53-year-old man presented with subacute progressive bilateral hypoacusis, with tinnitus in the left ear. During the following months, his hypoacusis worsened and he progressively developed bilateral stocking-type paresthaesia and gait instability. An audiometric examination showed bilateral neurosensorial hypoacusis and nerve conduction studies showed a mixed axonal polyneuropathy. A CT scan and MRI of the brain were normal and the electroencephalography (EEG) showed non-specific changes. He died of respiratory infection 10 months after onset of symptoms. Neuropathological examination showed neuronal loss, punctate, synaptic-like deposits of protease-resistant prionic protein (PrP(RES)) in the cerebral and cerebellar cortices and auditory nuclei. This is a rare case of sporadic CJD presenting with hearing loss.