Analysis of daily rhythms of adrenal function in men with quadriplegia due to spinal cord section.

Abstract

Circadian rhythms of adrenal function were studied in men with an isolated spinal cord and sympathetic chain due to traumatic cord injury at C4, C5 or C6. Six patients were studied shortly after the onset of paralysis, and four eight months or more after the injury. The purpose of the study was to gather information on afferent pathways to the central nervous system which affect physiological rhythmicity.The results obtained show that section of the spinal cord at C4, C5 or C6 dampens the established daily rhythms of 17-hydroxycorticosteroids excretion and suggests that, during and after rehabilitation, new patterns of information lead to the establishment of different rhythms. The results also show that section of the spinal cord and the sympathetic chain eliminates the effect of posture on the excretion of aldosterone and methylhydroxymandelic acid. The lack of postural control of aldosterone rhythms did not unmask a pattern related to an intrinsic secretory rhythm. The results suggest that afferent sensory stimuli from above the level of the injury modulate the central nervous system control of secretion of corticotrophin (ACTH), thus affecting the secretion of cortisol and the excretion of 17-OHCS. On the other hand, the connection of the central with the peripheral nervous system is necessary at all times to modulate secretion of aldosterone, epinephrine and norepinephrine.