Clinical features:
(1) impaired sleep or insomnia (often an early finding)
(2) fluctuating diplopia
(3) cerebellar dysfunction
(4) dysautonomia
(5) pyramidal and extrapyramidal dysfunction
(6) impaired cognition progressing to dementia
The patient does not respond to corticosteroid therapy.
Diagnosis often depends on a neuropathologic examination.
(1) spongiform degeneration in the thalamus
(2) widespread PrP(SC) deposits which are protease resistant
(1) presence of Asp178Asn PRNP mutation
Differential diagnosis:
(1) paraneoplastic cerebellar degeneration
(2) Hashimoto encephalopathy
(3) familial fatal insomnia
