Publication | Closed Access
Motor blocks in Parkinson's disease
417
Citations
0
References
1992
Year
Freezing episodes and related motor blocks are poorly understood, disabling, and therapeutically frustrating in Parkinson’s disease, and their epidemiologic and clinical characteristics have never been fully addressed. We surveyed 990 Parkinson’s disease patients, finding that 32 % experienced motor blocks. Motor blocks mainly affect gait, occurring in 86 % during start hesitation, 45 % when turning, and 25 % in narrow spaces; they are more common in patients with early gait/trunk symptoms, longer disease duration, higher Hoehn‑Yahr stage, and prolonged levodopa use, and are associated with levodopa‑induced dyskinesias, suggesting they arise from impaired motor task retrieval or execution linked to disease progression or levodopa side effects.
Freezing episodes and related phenomena (as a general term, motor blocks [MBs]) are poorly understood, particularly disabling, and a therapeutically frustrating problem in Parkinson9s disease (PD). Epidemiologic and clinical characteristics of MBs, as well as risk factors to develop MBs, have never been fully addressed. Herein, we report our database survey on 990 PD patients, of whom 318 (32%) had MBs. The majority of MBs were linked to gait. Start hesitation occurred in 86%, blocking on turning in 45%, and blocking in narrow spaces in 25% of patients. Initial parkinsonian symptoms in the upper body and tremor as the initial motor symptom were less likely to be associated with the presence of MBs (odds ratios |OR| 0.6 and 0.7, respectively), while initial symptoms affecting gait or trunk had higher association with MBs (OR = 1.58). Longer disease duration, higher Hoehn and Yahr stage, and longer duration of levodopa treatment are all significantly associated with the presence of MBs. We observed significant association between the existence of MBs and levodopa-induced dyskinesias to suggest similar pathophysiology. We propose that MBs in PD are abnormal retrieval or execution of complex motor tasks that can occur as a result of disease progression or as short- or long-term side effects of levodopa treatment.