Sleep disturbances in the spinal cord injured: an epidemiological questionnaire investigation, including a normal population.

Study Design: Epidemiological review.
Objective: To evaluate sleep disturbances in the spinal cord injured.
Setting: The Clinic for Para- and Tetraplegia, Hornbaek/Copenhagen, Copenhagen University hospital, Denmark.
Methods: All patients admitted with traumatic SCI during the 20-year period 1968-1987 were reviewed. The normal population consisted of 339, 222 men and 117 women. These groups were asked to fill in the self-administered Nordic Sleep Questionnaire (NSQ) containing 21 questions. Questions were added regarding employment, smoking, alcohol, coffee or tea consumption, height and weight. The questionnaire for SCI individuals included questions about bladder emptying method, mobility, and spasms. For the SCI population age at injury, cause of injury, neurological level, and functional class were retrieved.
Results: Four hundred and eight SCI individuals, 331 men and 77 women, answered the NSQ corresponding to a response rate of 83.8%. Forty-seven per cent had a cervical cord lesion and about half of the population had a complete motor lesion. In comparison with the normal population the SCI individuals had greater difficulty in falling asleep, described more frequent awakenings, slept subjectively less well, were more often prescribed sleeping pills, slept more hours, took more and longer naps, and snored more and for more years. In particular, spasms, pain, paraesthesia, and troubles with voiding were claimed to be part of the sleep problems.
Conclusion: In spite of the same average age and a higher body mass index in the normal than the SCI population, the SCI individuals showed significantly more sleep problems than the normal population.