Sleep Disorders in Parkinson’s Disease: A Case of REM Behavior Disorder

Abstract 

Sleep is an important aspect of cognitive function and is fundamental for maintaining memory, mood, and overall physical health. Individuals diagnosed with Parkinsonism and other movement disorders commonly face a variety of sleep-related disorders, including difficulty initiating or maintaining sleep, and abnormal movements during the night. (Alex Iranzo et al, 2024). The most frequently experienced parasomnias in Parkinsonian patients are rapid eye movement (REM) behaviour disorders. These issues 

—along with non-REM sleep disorders like sleep terrors, sleepwalking and sleep-related eating disorders— substantially reduce the quality of a patient’s life and increase the burden on caregivers. 

Case Report 

Our patient is a 74-year-old female with a two-year history of PD. Her initial symptoms included tremors in the left hand, oro-facial dyskinesias, along with complaints of posture instability, generalized bradykinesia, and micrographia. She was initially managed with Sinemet 25/100 mg, which was gradually increased. However, the patient developed severe orthostatic hypotension leading to dizziness, lightheadedness, and excessive somnolence. She also suffered four to five episodes of severe falls, leading to hospital admissions. Propranolol was substituted in the anti-hypertensive regimen, but did not alleviate the hypotensive episodes. Subsequently, she was prescribed a dose of pramipexole 0.125 mg twice a day after a normal creatinine clearance report. The Parkinsonism symptoms gradually improved, and her dose was gradually reduced to half a tablet twice a day. After six months of controlled PD, the patient’s family noticed a new onset of symptoms comprising sleep screaming followed by nocturnal enuresis. The screaming episodes were loud enough to wake the family, occurring 2 to 3 times at a frequency of 4 to 5 minutes each. They were followed by spontaneous nocturnal enuresis, after which the patient awoke in a confused state. She denied any hallucinations or vivid dreams. 

The patient was evaluated with a comprehensive hematological investigation, with emphasis on iron studies and inflammatory markers, which were subsequently found to be within normal range. The diagnostic workup also included magnetic resonance imaging of the brain and spinal cord, which was normal. 

She was evaluated with the RBD Screening Questionnaire (RBDSQ) and scored 8, which was above the cutoff. The patient refused polysomnography. Treatment was initiated with Clonazepam (1 mg at bedtime), combined with other non-pharmacological methods, such as a customized bed alarm that plays a soothing message from a familiar person, triggered by patient movement, leading to a reduction in the frequency of night terrors. 

Her past medical and surgical history includes secondary hypothyroidism for which she is taking levothyroxine, diabetes controlled on long-acting insulin, and oral hypoglycemic agents, and a hysterectomy. Gradually, her PD symptoms worsened, and her Unified Parkinson’s disease rating scale (UPDRS) deteriorated from 30 to 41 over nine months. 

Her tremor gradually progressed to the right side, and she became bedridden in the subsequent year.