Relation of Parkinson's disease subtypes to visual activities of daily living

Abstract

Visual perceptual problems are common in Parkinson's disease (PD) and often affect activities of daily living (ADLs). PD patients with non-tremor symptoms at disease onset (i.e., rigidity, bradykinesia, gait disturbance or postural instability) have more diffuse neurobiological abnormalities and report worse non-motor symptoms and functional changes than patients whose initial symptom is tremor, but the relation of motor symptom subtype to perceptual deficits remains unstudied. We assessed visual ADLs with the Visual Activities Questionnaire in 25 non-demented patients with PD, 13 with tremor as the initial symptom and 12 with an initial symptom other than tremor, as well as in 23 healthy control participants (NC). As expected, the non-tremor patients, but not the tremor patients, reported more impairment in visual ADLs than the NC group, including in light/dark adaptation, acuity/spatial vision, depth perception, peripheral vision and visual processing speed. Non-tremor patients were significantly worse than tremor patients overall and on light/dark adaptation and depth perception. Environmental enhancements especially targeted to patients with the non-tremor PD subtype may help to ameliorate their functional disability.

Fig. 1

Mean total score on the VAQ for NC, Tremor onset PD and Non-tremor onset PD. Error bars represent standard errors of the mean. The Non-tremor onset PD patients indicated worse functioning than the NC (p < .017) and Tremor onset PD groups (p < .017).

Fig. 2

Mean score for each of the eight scales of the VAQ for NC, Tremor onset PD and Non-tremor onset PD. Error bars represent standard errors of the mean. The Non-tremor PD patients indicated worse functioning on the light/dark adaptation, acuity/spatial vision, depth perception, peripheral vision and visual processing speed subscales than the NC group (p < .017). Non-tremor PD patients also indicated worse functioning on the light/dark adaptation and depth subscales (p < .017) than the tremor onset group. VAQ subscales: CD = color discrimination; GD = glare disability; LDA = light/dark adaptation; ASV = acuity/spatial Vision; DP = depth perception; PV = peripheral vision; VS = visual search; VPS = visual processing speed.