title: Verbal episodic memory declines prior to diagnosis in Huntington's disease.
abstract: Previous studies of verbal episodic memory in pre-diagnostic Huntington's disease (HD) have yielded mixed results; some evidence suggests that memory decline is evident prior to the onset of pronounced neurological signs of HD, whereas other data indicate that memory function remains normal throughout the pre-diagnostic period. This study examines verbal episodic memory in a sample of CAG expanded individuals who have not yet been clinically diagnosed, and who represent a wide range of points along the continuum from health to disease. The Hopkins Verbal Learning Test-Revised (HVLT-R) was administered to 479 participants (428 with the HD CAG expansion and 51 without), and performance was compared to neurobiological indices of disease progression, including a DNA-based estimate of proximity to clinical diagnosis, magnetic resonance imaging (MRI) measures of striatal volume, and neurologist ratings of motor signs. Lower HVLT-R scores were associated with closer proximity to clinical diagnosis and smaller striatal volumes; these relationships were found even in groups with no neurological signs of HD. The CAG expanded groups, including those with only minimal neurological signs, had significantly lower HVLT-R scores than the control group, and performance was worse in sub-groups that had more neurological signs consistent with HD. These findings indicate that verbal episodic memory is affected in early pre-diagnostic HD and may decline as striatal volumes decrease and individuals approach the motor diagnostic threshold.
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, 1101 E. 10th Street, Bloomington, IN 47405, USA.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Solomon
authors.forename: Julie C
authors.initials: JC
authors.lastname: Stout
authors.forename: Shannon A
authors.initials: SA
authors.lastname: Johnson
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Langbehn
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Aylward
authors.forename: Jason
authors.initials: J
authors.lastname: Brandt
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Ross
authors.forename: Leigh
authors.initials: L
authors.lastname: Beglinger
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hayden
authors.forename: Karl
authors.initials: K
authors.lastname: Kieburtz
authors.forename: Elise
authors.initials: E
authors.lastname: Kayson
authors.forename: Elaine
authors.initials: E
authors.lastname: Julian-Baros
authors.forename: Kevin
authors.initials: K
authors.lastname: Duff
authors.forename: Mark
authors.initials: M
authors.lastname: Guttman
authors.forename: Martha
authors.initials: M
authors.lastname: Nance
authors.forename: David
authors.initials: D
authors.lastname: Oakes
authors.forename: Ira
authors.initials: I
authors.lastname: Shoulson
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Penziner
authors.forename: Jane S
authors.initials: JS
authors.lastname: Paulsen
mesh_terms: D000328:Adult; D017668:Age of Onset; D016001:Confidence Intervals; D018450:Disease Progression; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000150:complications* / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D012737:Sex Factors; D013223:Statistics as Topic; D014706:Verbal Learning / Q000502:physiology