Tools are available to screen and evaluate sleep disorders (Luyster, 2015). Sleep disorders are very common in PwP; they are reported in as many as up to 96% of PwP and have a huge impact on their quality of life (Schrempf, 2014).

Common sleep disorders in PD include insomnia, sleepiness during the day with sleep attacks, restless-legs syndrome (RLS) and REM-sleep behaviour disorder (RBD).

Antiparkinsonian medicines may also cause or aggravate them. Excessive sleepiness leads to difficulty in remaining reasonably awake during the day.

If these symptoms are present before B1 therapy is started, they could be monitored to assess whether B1 is improving them.

As any other symptom, sleep disorders may temporarily increase in severity as a result of B1 “overdose” while searching the right dose during the trial and error phase.

RLS is characterized by an unpleasant urge to move the legs, especially at rest, in the evening and at night. RLS is associated with insomnia symptoms, depression, and several medical conditions.

The IRLSS is the most commonly used questionnaire for assessing RLS.

It is a self-report questionnaire with 10 items which collects information on intensity, frequency, severity of RLS symptoms, sleep problems, and their impact on daily life over the past week. It can therefore be used once a week.

It has been found to have “high levels of internal consistency, inter-examiner reliability, test-retest reliability over a 2-4 week period, and convergent validity.” (Restless Legs Syndrome Study Group, 2003).

It can be viewed at Wirral University Teaching Hospital (NHS) website: [external link]

RBD is also a very frequent condition in PwP. It entails acting one’s dreams, kicking, yelling, getting off the bed at night and may cause injuries to the sufferers and their partners (Schrempf, 2014). It also has prognostic value.

Once RBD is confirmed in a PwP, its frequency can be monitored during the search for the right dose of B1.

Anectodal reports suggest that, in some PwP on B1 right dose, the frequency of RBD episodes may decrease, and in PwP in whom the B1 dose is too high, it can increase as a sign of “overdose”.

The following single question, to be answered with a “Yes” or “No” (RBD1Q), has been used as a screening tool for RBD and found to have a sensitivity of 93.8% and a specificity of 87.2%:
Have you ever been told, or suspected yourself, that you seem to ‘act out your dreams’ while asleep (for example, punching, flailing your arms in the air, making running movements, etc.)?” (Postuma, 2012).

An online 13-question tool to screen RBD is available from the jotform website at: [external link].

This diary helps collect information on time to go to bed, time to fall asleep, number and length of awakenings during sleep, time of final awakening, qualitative rating of sleep quality, and free comments.

The PDSS is a simple 15-item questionnaire on nocturnal sleep experience in the past week based on commonly reported symptoms to which the respondent assigns a score based on perceived severity. It can therefore be used once a week.

It can be viewed on the Parkinson’s UK website at parkinsons_disease_sleep_scale.pdf [external link].

An extended version of PDSS (PDSS-2), developed to include restless legs syndrome, akinesia, pain, and sleep apnea in addition to nocturnal disturbances, has been validated and found to be a “reliable, valid, precise, and potentially treatment-responsive tool for measuring sleep disorders in PD.” (Trenkwalder, 2011).

The ISI is a self-report instrument listing 7 items to assess the degree of difficulty in falling asleep, staying sleep, and waking up too early over the past 2 weeks and monitor response to treatment. It can be used every two weeks.

Bastien et al. validated it and concluded that it “is a reliable and valid instrument to quantify perceived insomnia severity” (Bastien, 2001).

It can be viewed at Oncology Nursing Society website at: [external link].

The PSQI enables a general assessment of sleep quality over the past month. It has 19 items. It can then be used monthly. A global PSQI score greater than 5 indicates a poor sleeper.

It yielded a diagnostic sensitivity of 89.6% and specificity of 86.5% in distinguishing good and poor sleepers (Buysse, 1989; Beaudreau, 2012).

It can be viewed at the website at:,%20pittsburgh%20psqi.pdf [external link].

Selected references
Luyster FS, Choi J, Yeh CH, Imes CC, Johansson AE, Chasens ER. Screening and evaluation tools for sleep disorders in older adults. Appl Nurs Res. 2015 Nov;28(4):334-40.

Schrempf W, Brandt MD, Storch A, Reichmann H. Sleep disorders in Parkinson's disease. J Parkinsons Dis. 2014;4(2):211-21.

Walters AS, LeBrocq C, Dhar A, Hening W, Rosen R, Allen RP, Trenkwalder C; International Restless Legs Syndrome Study Group. Validation of the International Restless Legs Syndrome Study Group rating scale for restless legs syndrome, Sleep Med. 2003 Mar;4(2):121-32.

Postuma RB, Arnulf I, Hogl B, Iranzo A, Miyamoto T, Dauvilliers Y, Oertel W, Ju YE, Puligheddu M, Jennum P, Pelletier A, Wolfson C, Leu-Semenescu S, Frauscher B, Miyamoto M, Cochen De Cock V, Unger MM, Stiasny-Kolster K, Fantini ML, Montplaisir JY. A single-question screen for rapid eye movement sleep behavior disorder: a multicenter validation study. Mov Disord. 2012 Jun;27(7):913-6.

Trenkwalder C, Kohnen R, Högl B, Metta V, Sixel-Döring F, Frauscher B, Hülsmann J, Martinez-Martin P, Chaudhuri KR. Parkinson's disease sleep scale--validation of the revised version PDSS-2. Mov Disord. 2011 Mar;26(4):644-52.

Bastien CH, Vallières A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Med. 2001 Jul;2(4):297-307.

Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res. 1989 May;28(2):193-213.

Beaudreau SA, Spira AP, Stewart A, Kezirian EJ, Lui LY, Ensrud K, Redline S, Ancoli-Israel S, Stone KL; Study of Osteoporotic Fractures. Validation of the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale in older black and white women. Sleep Med. 2012 Jan;13(1):36-42.

Text author: Sergio Pièche
Page updated - 24/04/23