Parkinson’s disease (PD) affects 1-2 per 1000 of the population at any time. PD prevalence is increasing with age and PD affects 1% of the population above 60 years. PD occurs when brain cells that make dopamine, a chemical that coordinates movement, stop working or die. It is essentially a movement disorder that can cause tremors, slowness, stiffness, and walking and balance problems. It can also cause constipation, depression, memory problems and other non-movement symptoms. Symptoms and the progression of this disease Inter-individual variation, but sleep disturbance is one of the most common complaints.
One of the most prevalent symptoms in PD patients is excessive daytime sleepiness (EDS). EDS is described as inappropriate and undesirable sleepiness during waking hours and is a common non-motor symptom in PD, affecting up to 50% of patients. For people with PD, sleep becomes even more important as the body needs more time to restore and repair itself. The brain changes that are part of this disease can also cause sleep disruption, and some people have problems sleeping even before movement symptoms develop and a full diagnosis has been made. In fact, troubles with sleep is one of the important early warning signs of this disease.
PD patients may demonstrate a very specific sleep disorder, such as REM sleep behavior disorder (RBD). This diagnosis of RBD can actually predate the initial motor symptoms by up to 10-years and is one of the best known biomarkers for the disease. People with RBD will start acting out their dreams by shouting, swearing, grabbing, punching, jumping, and kicking while asleep. Sleep apnea is common amongst PD patients. Treating sleep apnea can be helpful removing the disruptive effects of sleep-disordered breathing that may be one of the triggers for REM sleep behaviour disorder. Patients might also have insomnia. Insomnia is the most frequent sleep disorder found in PD patients, with a prevalence ranging from 27 to 80%. The most frequent complaint is maintenance insomnia, with frequent awakenings and sleep fragmentation. It is actually thought that an early sign of restless leg syndrome may be a contributing cause of the insomnia complaint in PD patients. Poor sleep can be due to a number of things when you have Parkinson’s. The dementia and cognitive decline that can occur in Parkinson’s disease may also lead to circadian rhythm disorders.
Depression and anxiety can also be present in people with PD, which can also make sleeping more difficult. Some drugs that treat PD as well as those for mood and anxiety disorders may make it harder to fall or stay asleep. It’s a bit of a vicious circel, with the disease and treatment both causing sleep disturbances; sleep disturbances are risk factors for cognitive decline; cognitive decline can make sleep issues worse.
There is yet no cure for Parkinson’s Disease but it is important to address the treatable symptoms in order to create as much comfort as possible and maintain restorative sleep that will help minimize symptomatic progression for as long as possible.