by Dr Sandip Raha
Sleep disorder and its effect on QOL in PD is well recognised. The dopaminergic system as well as motor and neuropsychiatric symptoms are important components of sleep problems. There is some evidence that excessive daytime sleepiness may be related to dopamine agonist
The recently developed 15 item Parkinson’s Disease Sleep Scale (PDSS) addresses commonly reported sleep problems by a visual analogue scale measured against a 10 cm line to measure responses in decimal figures.
The aim of the audit was: to assess the prevalence of sleep disorder in a cohort of elderly PD patients, to ascertain any relationship to specific items of PDSS with severity of the disease, to see any relationship of low PDSS scores with different modality of treatment, and to determine frequency of overall low scores in relation to individual items of PDSS.
Patients with PD (brain bank criteria) were selected from a database of patients attending movement disorder clinic in a DGH. Selected patients were not any hypnotics / sedatives / sedative antidepressants, had intact cognition (MMSE 25 or more), living in their own home / family homes, and without any sleep disorder (sleep apnoea / COPD / O2 therapy).
Forty-one patients from a database of 126 patients were selected. The mean age was 71 years, (range 51-87), 30 male and 11 females.
Fifteen item PDSS was measured on a visual analogue scale by face to face interview in their own home / hospital clinics and scores were measured against a 10 cm ruler by superimposition of each item. Each item in PDSS scored 0-10 (0 being worst and 10 no symptoms); the lower the score the worse the sleep problems. PDSS scores were as follows: 14 patients scored 1-1.5, 13 patients 2-2.5, 14 patients 3-4.
Mean PDSS score in the LD group (Madopar / Sinemet only, 19 patients) was 106 (range 48–137), mean PDSS score in DA group (Dopamine agonist only, 9 patients) was 114 (range 66-136), and mean PDSS score in the CG group (combined Dopamine agonist + Levodopa +/- Selegiline /Entacapone, 13 patients) was 98 (range 49-129).
Motor-related symptoms in PDSS (4,5, 10-13) were equally common in all treatment groups. Analysis of individual items in PDSS showed: 88% scored 0-2 on Item 4,5 and 8 (nocturnal restlessness / nocturia), 77% scored 0-3 on item no. 12 & 14 (early morning motor symptoms & sleep refreshment), 66% scored low on item 3 & 15 (difficulty in staying sleep and morning sleepiness). 9 patients scoring <80 on PDSS: 4 were H&Y 3 – 4, 3 were H&Y 2 – 2.5, 2 were H&Y 1 – 1.5.
H & Y stages and PDSS scores:
We found that sleep related disorder is common in elderly PD patients – 15/41 patients (37%) had significant problems. In our study nocturia was the single most common symptom related to sleep disturbance (possibly due to elderly male patients).
There was no relationship between H & Y stages and sleep disorder (maybe due to small sample size or insensitive H &Y staging). We didn’t find any relationship between different treatment modalities and sleep disorder.
PDSS items most relevant to sleep disturbances in our group were: nocturnal restlessness and nocturia (Item 4,5,8), early morning motor symptoms and sleep refreshment (item 12, 14), difficulty in staying asleep and morning sleepiness (item 3, 15).
Larger studies are needed to ascertain validity of PDSS in elderly PD patients and measurement of the severity of PD through scales other than H&Y may be more useful.