Sleep disturbances and gastrointestinal dysfunction are associated with thalamic atrophy in Parkinson’s disease

BACKGROUND: Non-motor symptoms are common aspects of Parkinson’s disease (PD) occurring even at the prodromal stage of the disease and greatly affecting the quality of life. Here, we investigated whether non-motor symptoms burden was associated with cortical thickness and subcortical nuclei volume in PD patients. METHODS: We studied 41 non-demented PD patients. Non-motor symptoms burden was assessed using the Non-Motor Symptoms Scale grading (NMSS). Cortical thickness and subcortical nuclei volume analyses were carried out using Free-Surfer. PD patients were divided into two groups according to the NMSS grading: mild to moderate (NMSS: 0–40) and severe (NMSS: ≥ 41) non-motor symptoms. RESULTS: Thalamic atrophy was associated with higher NMSQ and NMSS total scores. The non-motor symptoms that drove this correlation were sleep/fatigue and gastrointestinal tract dysfunction. We also found that PD patients with severe non-motor symptoms had significant thalamic atrophy compared to the group with mild to moderate non-motor symptoms. CONCLUSIONS: Our findings show that greater non-motor symptom burden is associated with thalamic atrophy in PD. Thalamus plays an important role in processing sensory information including visceral afferent from the gastrointestinal tract and in regulating states of sleep and wakefulness.