Objective: To address diagnostic and prognostic issues in patients with
late-onset Huntington’s disease (HD).
Methods: We analyzed a cohort of 41 late-onset (>= 60 years) HD patients
and compared them to 39 late-onset patients referred for HD testing that
were negative for the HD-expansion and to 290 usual-onset (20-59 years)
HD patients. Disease severity was assessed by the Total Functional
Capacity Scale.
Results: Late-onset HD comprised 11.5% of our HD cohort. In total,
70.7% of late-onset HD patients had positive family history compared to
15.4% of late-onset expansion-negative patients (p < 0.001). Clinical
features at onset or presentation could not usefully distinguish between
late-onset expansion-positive and negative patients, excepting
hemichorea, which was absent from the HD group (p = 0.024). Chorea was
the first clinical feature in 53.7% and a presenting feature in 90.2%
of late-onset HD. The mutation hit rate for late-onset patients was
51.3%, lower than in usual-onset patients (p = 0.04). Frequencies of
chorea, cognitive impairment and psychiatric manifestations at onset or
presentation were not significantly different between late-onset and
usual-onset HD patients. Gait unsteadiness however was more common at
presentation in late-onset HD (p = 0.007). Late-onset HD patients
reached a severe stage of illness on average 2.8 years earlier than
usual-onset HD patients (p = 0.046).
Conclusions: A positive family history suggestive of HD, although absent
in a third of patients, remains a helpful clue in diagnosing late-onset
HD. Prognosis of late-onset HD in terms of Total Functional Capacity
appears no better and shows a trend of being somewhat less favorable
compared to usual-onset HD. (C) 2014 Elsevier Ltd. All rights reserved