Relationship between cognitive function and motor impairment severity in Parkinson's disease

Attention switching deficit in patients of Parkinson's disease who experience freezing of gait

Attention switching is involved in postural adjustments for gait. A deficit in attention switching was expected among patients having Parkinson's disease and experiencing freezing. There was a deficit in attention switching abilities among the patients of Parkinson's disease, having episodes of freezing of gait. The task accuracy and reaction time of the freezing group was significantly reduced compared to the non-freezing group having Parkinson's disease and healthy control group on total AST task performance, congruent and incongruent trials. The non-freezing group with Parkinson's disease was also slower than the healthy control group, but its accuracy was not affected. The results suggest that patients with freezing of gait experienced a stronger deficit in attention-switching than the non-freezing group of Parkinson's disease. This attention switching deficit among freezers may imply inappropriate allocation of attention for postural responses required for stepping and resulting in freezing. Also, the non-freezing group may have prioritized accuracy over time as a compensatory strategy that may be slowing their gait but prevents freezing.

Characterizing upper limb function in the context of activities of daily living in CLN3 disease

In CLN3 disease, impairments in motor function are frequently reported to have later onset compared to visual and cognitive decline, but upper limb motor function has yet to be explored in this population. In a cohort of 22 individuals with CLN3, we used a novel application of multiple measures to (1) characterize motor function, particularly of the upper limbs, in activities of daily living (ADLs), and (2) explore associations between motor function and age as well as visual ability, disease severity, and cognitive function, as evaluated by the Unified Batten Disease Rating Scale (UBDRS), a validated CLN3 disease measure. ADLs that required coordination, speed, and fine motor control were particularly challenging for children with CLN3 based on item-level performance across direct assessments (Jebsen-Taylor Hand Function Test [JTHFT] and MyoSet Tools) and caregiver reports (Pediatric Evaluation of Disability Inventory-Computer Adaptive Testing [PEDI-CAT] and Patient-Reported Outcomes Measurement Information System [PROMIS] Pediatric Upper Extremity). Poorer visual ability, disease severity, and cognitive function were associated with worse performance on these measures, whereas age had limited impact. These findings support the need for children with CLN3 to receive skilled clinical evaluation and treatment tailored to their individual needs, particularly in the context of ADLs, as their symptom profile progresses.