Sleep Woes, Gastrointestinal Dysfunction Linked With Thalamic Atrophy in Parkinson

Greater non-motor symptom burden may be associated with thalamic atrophy in Parkinson disease (PD), suggesting that the thalamus has a significant role in processing sensory information including visceral afferent from the gastrointestinal tract and regulating states of sleep, according to a study published in BMC Neuroscience.

The researchers evaluated 41 patients with PD without dementia in order to determine whether non-motor symptom burden was correlated with cortical thickness and subcortical nuclei volume in patients with PD. The Non-Motor Symptoms Scale grading (NMSS) was used as a measure. Based on this grading system, patients were separated into 2 group—mild to moderate and severe non-motor symptoms. The patients also completed a self-reported Non-Motor Symptoms Questionnaire (NMSQ).

“Non-motor symptoms have been recognised as an important component of Parkinson’s disease (PD). They occur in almost all the PD patients and can precede the onset of motor symptoms,” explained the authors. “Sleep disturbances, depression, gastrointestinal and urinary dysfunction, fatigue and cognitive impairment are often unresponsive to dopamine replacement therapy and greatly affect the quality of life of PD patients.”

The analysis results suggested that thalamic atrophy was associated with higher NMSQ and NMSS total scores. This correlation was due to the non-motor symptoms including sleep/fatigue and gastrointestinal tract dysfunction.

“We found significant correlation between worse sleep/ fatigue disturbances and thalamic atrophy in our cohort of PD patients. Sleep disturbances are one of the most common non-motor symptoms in PD occurring in up to 90% of PD patients,” noted the authors. “Sleep disturbances may precede by many years the classic motor abnormalities of PD33 and their frequency increases with the progression of the disease.”

The researchers also found that patients with severe non-motor symptoms had significant thalamic atrophy compared to the mild to moderate non-motor symptoms group.

According to the authors, future studies are necessary to investigate morphological brain changes and non-motor symptoms burden with the use of a larger cohort of patients with PD and with a specific scale in order to assess night and day time sleep disturbances.

Reference

Niccolini F, Wilson H, Giordano B, et al. Sleep disturbances and gastrointestinal dysfunction are associated with thalamic atrophy in Parkinson’s disease [published online October 22, 2019]. BMC Neuroscience. doi: 10.1186/s12868-019-0537-1.