Postural hypotension and abnormalities of salt and water metabolism in myelopathy patients.

To describe the clinical manifestations of postural hypotension (PH) in myelopathy patients a standardized interview and chart review were carried out. Of 232 myelopathy patients with more than 2 years of paralysis seen during a 2 year period, 30 had been treated for PH. All PH patients were paralysed at levels higher than thoracic 7. The highest risk patients were tetraplegic, motor complete, 24 of 73 (33%). The common symptoms of PH were those of reduced consciousness (100%), strength (75%), vision (56%) and breath (53%). Precipitating factors were hot weather (77%) bowel care (33%) and meals (30%). Symptoms worsened with the duration of paralysis in 12 patients. Chronic hyponatremia was found in 54% of the PH patients and 16% of those without, P < 0.001. Of five PH-hyponatremic patients with urine sodium and osmolality determinations, five continued to retain water (> 150 mOsm/kg) while four failed to conserve salt (> 19 mmol Na/L). PH is common among myelopathy patients with higher levels of paralysis, symptoms are variable, and abnormal salt and water metabolism often coexist.