Original article Excessive daytime sleepiness in Parkinson’s disease as assessed by Epworth Sleepiness Scale (ESS) Suresh Kumar, M. Bhatia * , M. Behari Department of Neurology, All India Institute of Medical Sciences, New Delhi 110029, India Received 22 February 2002; received in revised form 20 November 2002; accepted 21 November 2002 Abstract Objective: To assess daytime sleepiness in patients with Parkinson’s disease (PD) using the Epworth Sleepiness Scale (ESS). Material and methods: One hundred and forty-nine patients with PD (126 men, 23 women) and 115 age matched controls recruited from relatives of medical staff or spouses and other family members accompanying patients to the Movement Disorder Clinic of the All India Institute of Medical Sciences in New Delhi were included in the study. An ESS score of $ 8 was considered abnormal. Data obtained were analyzed using Chi square test for categorical variables and Student’s t-test for continuous variables. Results: The mean age of patients with PD was 58.37 (S.D. ¼ 10.45) years, and that of controls 56.50 (S.D. ¼ 11.45) years, with a mean duration of disease of 5.68 (S.D. ¼ 3.85) years. The mean ESS score was 4.9 (S.D. ¼ 3.63) and 2.17 (S.D. ¼ 2.54) in PD patients and controls, respectively (P , 0:05). Thirty-two patients with PD (21%) had an ESS score of . 8 whereas only 3% of controls scored $ 8 on the ESS (P , 0:05). Higher ESS scores were associated with a higher Hoehn and Yahr (H&Y) stage of disease and higher Unified Parkinson’s Disease Rating Scale (UPDRS) (part I, III and total) scores (P , 0:019, P , 0:013 and P , 0:011, respectively). Conclusion: Excessive daytime sleepiness was more common in PD patients as compared to controls. Higher ESS scores correlated significantly with higher H&Y stage and higher UPDRS (part I, III and total) scores. q 2003 Published by Elsevier B.V. Keywords: daytime sleepines; Parkinson’s disease; Epworth Sleepiness Scale 1. Introduction Daytime sleepiness is now increasingly reported in patients with PD, the frequency reported ranging from 26 to 65% [1–3]. Excessive daytime sleepiness (EDS) in PD patients may occur due to drug therapy (Levodopa, Selegi- line), primary sleep disorders (insomnia, restless legs syndrome) or disruption of circadian rhythm [4]. Due to its direct impact on road safety and public health, EDS has now become a symptom of concern for the treating physician [5,6]. For this reason it is necessary to screen PD patients for increased propensity to sleep during the day. The methods for evaluating EDS range from overnight polysomnography (PSG) followed by multiple sleep latency test (MSLT), maintenance of wakefulness test (MWT) and Epworth sleepiness score (ESS). We selected the ESS as the best measure to assess EDS on an outpatient basis, as it was inexpensive and relatively easy to administer in 5 min. The ESS has been validated extensively by various studies and found to be reliable [7–9]. In comparison with the MSLT and MWT, the ESS was found to have a sensitivity of 93.5% and a specificity of 100% [10]. Similarly, item and factor analysis has shown that the ESS is a unitary scale with high internal consistency and has a high test–retest reliability over a period of 5 months in normal subjects [7]. We conducted this study to evaluate the frequency of daytime sleepiness in Indian patients with PD using the ESS [7–10]. 2. Material and methods For the study 149 consecutive PD patients from the Movement Disorder Clinic at the All India Institute of Medical Sciences (AIIMS) were recruited from October 1998 to August 2000. Diagnosis was based on the UK PD severity Brain Bank diagnostic criteria [11–13]. PD 1389-9457/03/$ - see front matter q 2003 Published by Elsevier B.V. doi:10.1016/S1389-9457(03)00105-9 Sleep Medicine 4 (2003) 339–342 www.elsevier.com/locate/sleep * Corresponding author. Fax: þ 91-11-26588663. E-mail address: manvirbhatia@hotmail.com (M. Bhatia).