Cognitive motor interference during dual-task gait in essential tremor

Abstract

Background Functional ambulation requires concurrent performance of motor and cognitive tasks, which may create interference (degraded performance) in either or both tasks. People with essential tremor (ET) demonstrate impairments in gait and cognitive function. In this study we examined the extent of interference between gait and cognition in people with ET and controls during dual-task gait. Methods We tested 62 controls and 151 ET participants (age range: 72–102). ET participants were divided into two groups based on median score on the modified Mini Mental State Examination. Participants walked at their preferred speed, and performed a verbal fluency task while walking. We analyzed gait velocity, cadence, stride length, double support time, stride time, step width, step time difference, coefficient of variation (CV) of stride time and stride length. Results Verbal fluency performance during gait was similar across groups (p=0.68). Velocity, cadence and stride length was lowest whereas step time difference (p=0.003), double support time (p=0.009), stride time (p=0.002) and stride time CV (p=0.007) were highest for ET participants with lower cognitive scores (ETp-LCS), compared with ET participants with higher cognitive scores (ETp-HCS) and controls. ETp-LCS demonstrated greatest interference for double support time (p=0.005), step time difference (p=0.013) and stride time coefficient of variation (p=0.03). Conclusions ETp-LCS demonstrated high levels of cognitive motor interference. Gait impairments during complex tasks may increase risk for falls for this subgroup and underscore the importance of clinical assessment of gait under simple and dual-task conditions.

Balance Confidence and Falls in Nondemented Essential Tremor Patients: The Role of Cognition

“…Details about our cohort have been reported previously 9, 15 . Briefly, participants were recruited as future brain donors to the Essential Tremor Centralized Brain Repository (ETCBR).…”

“…The gait mat was placed in the middle of a quiet hallway in participants’ homes. We had ascertained that each participant had sufficient space for collecting gait data and have reported the procedure in detail previously 9, 15 . We analyzed the following gait measures that were sensitive in differentiating people with ET from controls 15 : speed, cadence, step length, step time difference, and percent of gait cycle spent in double support.…”

“…We recently observed that gait impairments were worse in people with ET when performing a cognitive task during gait 15 . Performance decrement was most prominent in a subset of people with ET with lower scores on a cognitive test (ET-LCS).…”

“…We collected new retrospective falls data on our cohort of 213 subjects, for whom we had previously only reported quantitative gait data 9, 15 .…”

The heterogeneity of drug response as the basis of identification of essential tremor subtypes

“…По мере прогресси-рования заболевания присоединяются другие дви-гательные симптомы: интенционный тремор, тремор покоя, нарушения походки, нистагм [6,7,15,22,26]. У ряда больных с ЭТ наблюдаются немоторные про-явления -когнитивные нарушения, личностные изменения, депрессия, обонятельные дисфункции, нарушения слуха [22,30,31].…”