Table 2.

Clinical characteristics of all FFI patients

Parameter	Common	Frequent	Less frequent	Rare
Cluster A (sleep-related symptoms)
Insomnia	87.0%
Sleep-related involuntary movements			46.6%
Sleep-related dyspnoea			25.2%
Laryngeal stridor			32.1%
Cluster B (neuropsychiatric symptoms)
Rapidly progressive dementia	83.2%
Psychiatric symptoms		66.4%
Ataxia		56.5%
Pyramidal sign			25.2%
Parkinsonism			36.6%
Myoclonus			29.8%
Bulbar syndrome			25.2%
Diplopia				22.1%
Cluster C (progressive sympathetic symptoms)
Sweating		55.0%
Hypertension			33.6%
Weight loss			30.5%
Tachycardia				24.4%
Irregular breathing				16.8%
Hyperthermia				19.8%
Others*				13.0%

*Others in cluster C represent constipation, urinary retention and sexual dysfunction.

FFI, fatal familial insomnia.;