title: Gait disorders in fatal familial insomnia.
abstract: BACKGROUND
  Fatal familial insomnia (FFI) is a hereditary autosomal-dominant prion disease linked to a mutation of the prion protein gene and characterized by sleep and autonomic abnormalities at onset followed by motor disturbances. We describe gait abnormalities in 13 FFI cases with different disease durations.
  
  
  METHODS
  Clinical records and corresponding videos of 13 FFI cases were regularly monitored from disease onset to death.
  
  
  RESULTS
  Gait disturbances appeared in all FFI subjects 5 ± 2 months after disease onset following a distinct progression for the 2 genetic FFI variants. Homozygous patients developed only a cautious gait with some difficulties in turning and in tandem gait; heterozygous patients showed a clear progressive worsening of equilibrium with latero/retropulsion ultimately preventing standing and walking unaided.
  
  
  CONCLUSIONS
  The severity and features of gait dysfunction in FFI are related to the duration of the disease, which in turn is a result of the genotype. The evolving gait dysfunction in the disease course may mirror the spread of neuronal degeneration from the thalamus to other brain areas involved in the control of gait or may be the functional effect of a disturbed neuronal network in which the thalamus is a crucial relay.
authors.affiliation: IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; Department of Biomedical and NeuroMotor Sciences (DIBINEM), Alma Mater Studiorum, University of Bologna, Bologna, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Cortelli
authors.forename: Margherita
authors.initials: M
authors.lastname: Fabbri
authors.forename: Giovanna
authors.initials: G
authors.lastname: Calandra-Buonaura
authors.forename: Sabina
authors.initials: S
authors.lastname: Capellari
authors.forename: Paolo
authors.initials: P
authors.lastname: Tinuper
authors.forename: Piero
authors.initials: P
authors.lastname: Parchi
authors.forename: Elio
authors.initials: E
authors.lastname: Lugaresi
mesh_terms: D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D005684:Gait / Q000502:physiology*; D006720:Homozygote; D006801:Humans; D034062:Insomnia, Fatal Familial / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000235:genetics / Q000503:physiopathology*; D009154:Mutation / Q000235:genetics
keywords: fatal familial insomnia; gait disorder; imbalance; thalamus