Patients with Parkinson’s who have freezing have worse motor symptoms
A new study led by Ryan P. Duncan, PT, DPT, of Washington University in St. Louis and colleagues set out to determine whether balance impairments differ between groups of people with Parkinson’s disease who either have or do not have a history of freezing gait. Researchers took into account disease severity and duration and age.
In the more advanced stages of Parkinson’s disease, people will experience depression, dementia and a temporary, involuntary inability to move called freezing episodes. These episodes are impossible to predict. When freezing occurs the persons legs actually freeze and become stuck to the floor. Freezing can last a few seconds or minutes and can become a significant danger of the person falling at the beginning of the episode or the end.
Patients describe this episode as their feet being glued to the floor. These episodes are more likely to occur during walking, while walking towards doorways or obstacles, when turning or changing direction, in crowded or cluttered places, during group conversation or if medication is not working properly.
Duncan stated "We also know that freezers tend to fall more than non-freezers, and while we recognize that there are gait differences between freezers and non-freezers, researchers have not yet standardized clinical balance assessments to determine if balance differs between these patients.”
The research team evaluated balance using three scoring systems on 78 participants, 58% male, with a mean age of 68.1 years.
The scoring systems were the Balance Evaluation Systems Test (BESTest) consisting of 36 36 items, grouped into 6 systems: “Biomechanical Constraints,” “Stability Limits/Verticality,” “Anticipatory Postural Adjustments,” “Postural Responses,” “Sensory Orientation,” and “Stability in Gait.
The second system was the Mini-BEST, a shortened version of the BESTest which has selected test items from 4 balance systems (anticipatory, reactive postural control, sensory orientation, dynamic gait.
The third was the Berg Balance Scale (BBS) used to measure balance in older people with impairment in balance function by assessing the performance of functional tasks. The BBS is considered the gold standard for both Parkinson's and non-Parkinson's patients.
The results showed 32 participants were considered freezers and had worse motor symptom severity and longer disease duration.
The team considered whether the individual six sections of the BEST differentiated freezers.
There were no differences found between the groups in the first section that addressed biomechanical constraints such as ankle strength and range of motion. The second section, stability limits and verticality concerns during sitting and forward reaching and the third section which considers anticipatory postural adjustments such as while standing on one leg.
In the fourth section, postural responses such as compensatory stepping reactions, freezers had significantly lower scores (f=14.39, P<0.001).
On the fifth section, sensory orientation such as standing on firm or foam surfaces with eyes open and closed, there were no differences between the groups.
And the last section, section six, assesses stability and gait such as while walking and making a pivot turn, poorer results were seen for freezers.
In their conclusion the researchers write “regardless of motor symptom severity, years since diagnosis, and age, freezers had more severe balance impairment than non-freezers as measured by the BESTest and Mini-BESTest. Physical therapists should consider addressing postural response and stability in gait problems in PD patients with FOG (freezing of gait).
In conclusion Duncan remarks "Because freezers may have deficits in postural responses and stability and gait, rehab clinicians might tailor their interventions to these areas to improve balance in patients with freezing problems.”
This study was reported by Duncan at the World Parkinson Congress