Verbal episodic memory declines prior to diagnosis in Huntington's disease.
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.
Solomon
Andrea C
AC
Department of Psychological and Brain Sciences, Indiana University, 1101 E. 10th Street, Bloomington, IN 47405, USA.
Stout
Julie C
JC
Johnson
Shannon A
SA
Langbehn
Douglas R
DR
Aylward
Elizabeth H
EH
Brandt
Jason
J
Ross
Christopher A
CA
Beglinger
Leigh
L
Hayden
Michael R
MR
Kieburtz
Karl
K
Kayson
Elise
E
Julian-Baros
Elaine
E
Duff
Kevin
K
Guttman
Mark
M
Nance
Martha
M
Oakes
David
D
Shoulson
Ira
I
Penziner
Elizabeth
E
Paulsen
Jane S
JS
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