Freezing of gait — the description for a Parkinson’s symptom in which a person’s feet become briefly “glued to the floor,” preventing forward movement despite an intention to walk — is associated with more severe disease and worse motor and non-motor disability, a study reports.
The study, “Factors associated with freezing of gait in patients with Parkinson’s disease,” was published in Neurological Sciences.
Such freezing, a form of akinesia or abnormal movement, while walking is estimated to affect about 50 percent of Parkinson’s patient in later, more advanced, disease stages. Freezing of gait (FOG) is a well-known cause of falls, and a loss of independence and lower quality of life in these patients, but can be difficult for clinicians to assess and treat.
“FOG measurement is quite challenging as objective FOG assessment requires a continuous ambulatory system that can monitor locomotion and FOG episodes,” the researchers wrote.
Studies have suggested that FOG is related to an array of contributing factors, including longer disease duration, more severe disability, wearing off of levodopa treatment, and urinary plus cardiovascular symptoms.
Given this variety, scientists at the Chonnam National University Hospital in Gwangju, South Korea, wanted to estimate the prevalence of FOG and pinpoint factors that could independently contribute to its occurrence in a population of Parkinson’s patients.
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A total of 157 patients (ages 62 to 77) were recruited. All “had a positive response to levodopa and did not have clinically significant brain lesions, as seen by magnetic resonance imaging,” tje researchers wrote.
Patients’ age at symptom onset, disease duration, and past plus current medications were all evaluated.
A series of scales/questionnaires were used to assess distinct domains:
- To determine disease stage, the team used the Unified PD Rating Scale (UPDRS) and modified Hoehn and Yahr scale (mHYS). Both UPDRS and mHYS rate severity of symptoms in Parkinson’s disease;
- To evaluate cognitive status, the Korean version of mini-mental status examination (K-MMSE) was applied;
- To assess depression, researchers used the Beck’s depression inventory — a 21-item, self-rated scale that evaluates depression-related symptoms;
- Non-motor symptoms were evaluated using the non-motor symptom assessment scale for PD (NMSS). NMSS is a self-completed patient questionnaire with 30 qualitative questions covering all important non-motor symptoms of Parkinson’s;
- Lastly, FOG was assessed using the FOG questionnaire, which determines the severity and frequency of freezing of gait, plus disturbances in gait.
Results showed that 70.7 percent — 111 of 157 — of examined patients had FOG.
Researchers reported that “patients with FOG were older [mean age of 71.1], had long disease duration, were taking higher doses of dopaminergic agents, and had higher motor and non-motor scores than those without FOG.” Higher scores mean greater disability.
Among non-motor symptoms, those affecting the cardiovascular, gastrointestinal and urinary systems were more frequent in patients with FOG than in those without. In accordance, cardiovascular, gastrointestinal, urinary and miscellaneous NMSS domain scores were significantly higher in patients with FOG.
Results showed that higher mHYS and UPDRS part II scores — the section of the scale that refers to motor experiences in daily living — and NMSS total scores were significant predictors of greater freezing of gait severity and frequency.
Evidence indicates that non-motor symptoms like anxiety, fatigue, and pain impact mobility in PD patients, but this study found no difference between mood/cognition scores in patients with and without FOG.
The cause or mechanism of action for freezing of gait in Parkinson’s patients “remains unclear,” the study concluded. But its researchers saw possible association between FOG and both motor and non-motor disabilities. They suggest that physicians “consider the non-motor features, the motor, and activities of daily living states of the patients for the proper management of FOG.”
And they recommended further studies “to fully assess the role of non-motor symptoms in the mechanism of action during FOG.”