Article

Huntington's disease (HD) pre-manifest mutation carriers (PMCs) present
early-onset gait disturbances. Gait initiation encompasses the preparation and
execution of the first step. By using paradigms with and without external cues, a
gait initiation analysis can highlight the interaction between motor and
cognitive aspects of movement preparation and execution. Hence, gait initiation
disorders may constitute particularly interesting early markers of HD. The
objective of the present study was to quantify gait initiation in PMCs. In a
case-control study, 17 PMCs (median age: 36.5) were compared with a group of 25
healthy controls (HCs, median age: 36) for gait initiation and a group of 57 HCs
(median age: 38) for gait. Presymptomatic mutation carriers displayed a shorter
first step duration and lower-amplitude postural adjustments. For the first step
duration and speed, these impairments were more pronounced under self-triggered
(ST) conditions. The PMCs displayed a lower gait speed, cadence and stride length
and higher stride-to-stride variability. The latter parameter seemed capable of
differentiating between PMCs and HCs with adequate sensitivity (0.81) and
specificity (0.87). We confirmed the early-onset impairment of gait in general
and first step execution in particular in PMCs (particularly under ST
conditions). The temporal parameters of step execution (e.g. duration) and
spatial parameters of postural adjustment (e.g. a backward shift in the centre of
pressure) may be worth investigating as early markers of HD. However, two such
parameters (stride-to-stride variability and first step duration under ST
conditions) already appear to be sufficiently reliable diagnostic tools for
differentiating between PMCs and HCs.
CI - Copyright (c) 2011 Elsevier B.V. All rights reserved.

Langue : ANGLAIS