title: [Fatal familial insomnia--a rare differential diagnosis in dementia].
abstract: Fatal familial insomnia (FFI)--first reported in 1986--is a hereditary prion disease with autosomal-dominant inheritance, caused by a missense-mutation at codon 178 of the prion-protein gene (PRNP) on chromosome 20. A methionine-valine polymorphism at codon 129 of PRNP expresses different phenotypes. The clinical features of FFI are characterized by a disrupted sleep-wake cycle with resulting fluctuations of vigilance, autonomic hyperactivation, myoclonus, motor abnormalities and by cognitive disturbances. The age of onset is between middle to late adulthood (51 +/- 7.1 years), disease duration varies between 8 and 72 months (18.4 +/- 17.3 months) and is ultimately fatal. We report the case of a 57-year-old man with a diagnosed FFI by molecular-genetic investigation who suffered from increasing memory- and sleep-disturbance as well as physical restlessness and impotence for 9 months. Clinical features were motor symptoms, generalized myoclonus and hyperactivity with reduced attention and concentration. The neuropsychological findings were a severe disturbance of attention and memory as well as incipient deficits in executive functions. The cranial MRI and repeated EEG were normal; in detailed laboratory tests including CSF no abnormalities were detected. The clinical course was characterized by rapid decline of the motor and cognitive skills; the patient died 15 months after onset. Histological analysis showed the typical changes of FFI (spongiform changes at hippocampus and regio entorhinalis, severe gliosis in the thalamus and mild deposits of abnormal prion protein).
authors.affiliation: Psychiatrische Universitätsklinik Zürich, Klinik für Soziale Psychiatrie und Allgemeinpsychiatrie ZH West, Schweiz. mirko.friedrich@puk.zh.ch
authors.forename: M
authors.initials: M
authors.lastname: Friedrich
authors.forename: R
authors.initials: R
authors.lastname: Körte
authors.forename: C
authors.initials: C
authors.lastname: Portero
authors.forename: T
authors.initials: T
authors.lastname: Arzberger
authors.forename: H A
authors.initials: HA
authors.lastname: Kretzschmar
authors.forename: I
authors.initials: I
authors.lastname: Zerr
authors.forename: W
authors.initials: W
authors.lastname: Nacimiento
mesh_terms: D017668:Age of Onset; D001921:Brain / Q000473:pathology; D003704:Dementia / Q000175:diagnosis* / Q000473:pathology / Q000523:psychology*; D003937:Diagnosis, Differential; D004569:Electroencephalography; D017809:Fatal Outcome; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D034062:Insomnia, Fatal Familial / Q000175:diagnosis* / Q000473:pathology / Q000523:psychology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011328:Prions / Q000737:chemistry; D012893:Sleep Wake Disorders / Q000209:etiology; D013788:Thalamus / Q000473:pathology
chemical_list: D011328:Prions