Bilateral oculosympathetic paresis associated with loss of nocturnal melatonin secretion in patients with spinal cord injury.
BACKGROUND
Lesions along the sympathetic pathway to the eye produce oculosympathetic paresis (OSP, Horner's syndrome). The oculosympathetic pathway descends from the hypothalamus through the cervical spinal cord and ascends to the superior cervical ganglion (SCG), which innervates sympathetic targets in the ipsilateral face and eye. This pathway appears to closely co-localize with a similar retino-pineal neural pathway from the hypothalamus through the cervical spinal cord and SCG to the pineal gland. As such, lesions along this shared pathway, such as occur in neurologically complete injury to the cervical spinal cord (tetraplegia), would be predicted to result in simultaneous OSP and loss of pineal melatonin production. Loss of melatonin production may contribute to the pervasive sleep disruption observed in patients with tetraplegia.


METHODS
We assessed the presence of OSP by photographic documentation of ptosis and pupillary dilation response to cocaine eye drops in 5 individuals with neurologically complete damage to their upper thoracic or lower cervical spinal cord. We correlated these results with an analysis of the pattern of melatonin production in these same individuals.


RESULTS
Bilateral OSP was present in individuals with cervical spinal cord injury; each also lacked significant production of melatonin. No evidence of OSP was observed in the 2 individuals with thoracic spinal cord injury below the level of the oculosympathetic pathway. Both had normal circadian rhythms of melatonin production, with timing and amplitude of the rhythm within normal parameters.


CONCLUSIONS
The presence of bilateral oculosympathetic paresis can be predictive of the complete loss of the nocturnal production of melatonin.
Zeitzer
Jamie M
JM
Division of Sleep Medicine, Harvard Medical School Boston, Massachusetts, USA.
Ayas
Najib T
NT
Wu
Allan D
AD
Czeisler
Charles A
CA
Brown
Robert
R
D000328:Adult; D002574:Cervical Vertebrae; D002940:Circadian Rhythm / Q000502:physiology; D006732:Horner Syndrome / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D011680:Pupil / Q000502:physiology; D013119:Spinal Cord Injuries / Q000097:blood* / Q000150:complications* / Q000503:physiopathology; D013904:Thoracic Vertebrae
D008550:Melatonin