Neurology -- Correspondence for Ondo et al., 57 (8) 1392-1396

Correspondence published:

Reply to Letter to the Editor: William G Ondo, Joseph Jankovic (2 April 2002)

Daytime sleepiness and other sleep disorders in Parkinson’s disease: Homann C N, M Forstner, G Ivanic, and E Ott (2 April 2002)

Reply to Letter to the Editor 2 April 2002

William G Ondo
Baylor College of Medicine Houston TX,
Joseph Jankovic
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Re: Reply to Letter to the Editor

wondo{at}bcm.tmc.edu William G Ondo, et al.

We appreciate the comments of Homann et al. and generally agree with their suppositions. The frequency with which our PD patients admitted to falling asleep while driving is higher than other major series. [3, 4, 5, 6] Since their letter was submitted the sleep survey of the Canadian Movement Disorders Group was published as a full paper. [7] We attribute our high rate of driving sleepiness to our patient demographics. First, patients were told that the data would be confidential. Second, our clinic serves as a tertiary referral center for the southern United States and, therefore, our patients tend to have more advanced disease, a longer duration of disease, and older age, all of which can correlate with sleep problems. Third, many of our patients live in rural areas and are forced to drive much longer distances than would be required in more densely populated areas, such as Europe. Likewise, there is very little public transportation, whereas gasoline is relatively inexpensive. Fourth, the state of Texas has particularly liberal driving laws. Even patients with active epilepsy are not legally prevented from driving. In short, we suspect that patients in our catchment area drive more than in most areas of the world, and are therefore more prone fall asleep while driving. We referenced a study that reported a higher incidence of falling asleep in long-haul truck drivers, compared to our PD population, suggesting that baseline driving characteristics greatly influence these figures. [8] We do not feel that driving should be legislatively limited for patients with PD who take dopaminergic medications, however, we do counsel them regarding this potential problem. Further studies are needed to determine the mechanisms of excessive drowsiness and to define the predictors of altered daytime alertness and tendency to fall asleep while driving [9].
References
1. Ondo WG, Dat Vuong K, Kahn H, Atassi F, Kwak C, Jankovic J. Daytime sleepiness and other sleep disorders in Parkinson's disease. Neurology 2001;57:1392-1396.
2. Frucht SJ, Greene PE, Fahn S. Sleep episodes in Parkinson's disease: a wake-up call. Mov Disord 2000;15:601-603.
3. Lang AE, Hobson DE, Martin W, J Rives J. Excessive daytime sleepiness and sudden onset sleep in Parkinson's disease: A survey from 18 Canadian movement disorders clinics. Neurology 2001;56:S40.001(Abstract)
4. Gimenez-Roldan S, Dobato JL, Mateo D. Vehicle drivers with Parkinson disease: behavior schedules of a patient sample from the Community of Madrid. Neurologia. 1998;13:13-21.
5. Homann CN, Trummer M, Wenzel K, et al. Sleep attacks and severe road accidents in patients with parkinson's disease - an unfrequent finding! Mov Disord 2001;16:44-44.(Abstract)
6. Tan EK, Lum SY, Fook-Chong SMC et al. Evaluation of somnolence in Parkinson's disease: Comparison with age and sex matched controls. Neurology 2002;58:465-468.
7. Hobson DE, Lang AE, Martin WRA, et al. Excessive daytime sleepiness and sudden-onset sleep in Parkinson disease. A survey by the Canadian Movement Disorders Group. JAMA 2002;287:455-463.
8. Hakkanen J, Summala H. Sleepiness at work among commercial truck drivers. Sleep 2000;23:49-57.
9. Rye DB, Jankovic J. Emerging views of dopamine in modulating sleep/wake state from an unlikely source: PD. Neurology 2002;58:341-346.

Daytime sleepiness and other sleep disorders in Parkinson’s disease 2 April 2002

Homann C N
University Hospital Graz Austria,
M Forstner, G Ivanic, and E Ott
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Re: Daytime sleepiness and other sleep disorders in Parkinson’s disease

nik.homann{at}kfunigraz.ac.at Homann C N, et al.

I read with great interest the recent article by Ondo et al. [1] on excessive daytime sleepiness (EDS) and falling asleep while driving in PD patients. The Ondo et al. publication is one of the few systematic surveys of these phenomena, which they report to occur as 87.5% for EDS and 22.6% for falling asleep. Their study was performed also to report recent cases of dopa-mine agonist related sleep attacks and automobile collisions. [2] In response to these initial reports a warning was appended to the inserts of two of these agonists, advising patients not to drive when taking these medications. [2] While driving contributes much to financial self-support and quality of life the Ondo et al. survey gives the impression that PD patients on dopaminergic agents pose a major threat to society and thus supports the notion of a general driving ban for PD patients. However, the finding that almost a quarter of PD patients has fallen asleep at the wheel is not consistent with the literature. Where only 4%, [3] 1% [2] and 5% [2] of patients had fallen asleep while driving. Ascertainment bias can only partially explain this discrepancy, as it would be expected for all the studies. Regional differences in driving may also have an effect. In this study it shows that 92% of the PD population was still driving. In contrast, Lang found that only 65% of PD patients recruited from 18 centers throughout Canada were driving. [3] An older German study reported that only 20% of PD patients were active drivers, a figure that matched that of a recent Spanish survey. [4] It can therefore be assumed that due to local driving habits, patients with older age and higher disease stages and higher propensity for EDS were included in the Ondo et al. study. This makes generalization of their results diffi-cult. Important for evaluating the danger for patient and society is not the propensity for EDS but rather how this translates into actual damage to property and health. The frequency of acci-dents in the Ondo's population was not specified. Accidents caused by sleep attacks are rare [2] and the scarce descriptions give accounts of minor injuries or property damage only. [3] The three existing comparative studies all suggest that PD patients are not more prone to cause accidents than the general public. [5] Judging from the current literature a general driv-ing ban therefore does not seem justified, but further population-based studies are needed. References 1. Ondo WG, Dat Vuong K, Kahn H, Atassi F, Kwak C, Jankovic J. Daytime sleepiness and other sleep disorders in Parkinson's disease. Neurology 2001;57:1392-1396. 2. Frucht SJ, Greene PE, Fahn S. Sleep episodes in Parkinson's disease: a wake-up call. Mov Disord 2000;15:601-603. 3. Lang AE, Hobson DE, Martin W, J Rives J. Excessive daytime sleepiness and sudden onset sleep in Parkinson's disease: A survey from 18 Canadian movement disorders clinics. Neurology 2001;56:S40.001(Abstract) 4. Gimenez-Roldan S, Dobato JL, Mateo D. Vehicle drivers with Parkinson disease: behavior schedules of a patient sample from the Community of Madrid. Neurologia. 1998;13:13-21. 5. Homann CN, Trummer M, Wenzel K, et al. Sleep attacks and severe road accidents in patients with Parkinson's disease - an unfrequent finding! Mov Disord 2001;16:44-44.(Abstract)