Circadian rhythm in patients with spinal cord injuries

Abstract

Spinal Cord Injury (SCI) is damage to the spinal cord that may result in the loss of mobility. Frequent causes of damage are trauma (motor vehicle accident, falls, etc.) or disease (polio, spina bifida, Friedreich's Ataxia, etc.). However, abnormality in circadian rhythm has been observed in SCI. Melatonin is the primary hormone of the pineal gland and acts to regulate the body's circadian rhythm. Normally, melatonin levels begin to rise in the mid-to-late evening, remains high for most of the night, and then decreases in the early morning hours. Patients with SCI have a lower melatonin secretion during the hours of darkness than in healthy subjects. This may contribute to impaired sleep at night, fatigue during the day and affect pain perception. Disturbed level of melatonin has also been reported in SCI patients that are associated with disturbances in circadian rhythm. Therefore, circadian rhythm can be important in the pathophysiology and treatment of SCI patients and it is important to know the time and the level of melatonin in order to prescribe the appropriate treatment regimen. The expanding science of circadian rhythm biology and a growing interest in human clinical research on circadian rhythm in patients with spinal cord injuries inspired this review. This article reviews the relationship of circadian rhythm in patients with SCI. doi : 10.5214/ans.0972.7531.2009.160110 Competing interests: None. Source of Funding: None Received Date: 14 March 2009 Revised Date: 27 March 2009 Accepted Date: 09 April 2009