Parkinson’s patients with freezing gait have disturbed sleep

People with Parkinson’s disease who experience freezing of gait – a sudden inability to initiate or continue movement, often resulting in a fall – wake up several times during the night, feel sleepy during the day, and have rapid eye movement (REM) sleep behaviour disorder. This can exacerbate confusion and forgetfulness as REM sleep plays a role in the maintenance of many cognitive processes.

These are the key findings of a study by researchers at São Paulo State University (UNESP) in Brazil and Grenoble Alps University (UGA) in France, published in the journal Sleep Medicine.

In a systematic review of 20 studies on sleep quality and freezing of gait, the researchers found a correlation between these two important symptoms of Parkinson’s disease. They stress the importance of evaluating and monitoring the correlation in patients and believe the finding may contribute to the development of novel treatment protocols.

‘There was a suspicion that the two phenomena were linked, and our analysis of the literature appeared to confirm this hypothesis. The reason is that freezing of gait has a similar physiopathology to sleep quality,’ said Fabio Barbieri, head of the Human Movement Research Laboratory (MOVI-LAB) at the UNESP’s Bauru campus.

However, he added, scientists do not yet know whether freezing of gait or poor sleep quality comes first. ‘The studies point to a more than 95% probability that a patient who experiences freezing episodes will also have a sleep disorder, but it’s also been found that a pronounced deterioration in sleep quality tends to be a sign that the patient may experience freezing episodes in future. The two symptoms are interconnected, and we haven’t yet been able to determine which appears first,’ he said.

Parkinson’s disease affects sleep generally, regardless of whether the patient has freezing of gait. In an unpublished study, Barbieri’s group and collaborators at UGA compared the effect of medication on sleep quality. ‘We found that sleep quality deteriorated when dopaminergic medication was stopped for sleep,’ he said.

No specific treatment for freezing of gait is available, although it is one of the main reasons for falls among Parkinson’s patients. Alongside tremor and cognitive impairment, freezing is one of the factors that lower the quality of life for these patients.