P0655 - Outpatient Management of Orthostatic Hypotension as a Chronic Complication of Upper Spinal Cord Injury

Case: AL is an 18-year-old man with a history of incomplete tetraplegia following traumatic cervical spinal cord injury (SCI), complicated by orthostatic hypotension (OH), neurogenic bladder, and neuropathic pain, who presented to the clinic to establish care. He reported chronic episodes of pre-syncope and diaphoresis several times daily with no loss of consciousness, provoked by rapid positional changes and partially alleviated by leaning forward. Pre-syncopal episodes had persisted despite treatment with 5 mg midodrine twice daily for OH since inpatient admission 14 months prior. On exam, AL’s blood pressure was 96/64, wearing an abdominal binder. Cardiovascular auscultation was unremarkable. The dose of midodrine was increased to 10 mg in the morning and afternoon. At follow up, AL reported subjective improvement and denied adverse effects including symptoms of hypertension, such as headache, flushing or blurred vision.

Discussion: SCI superior to the T6 vertebra can cause autonomic dysfunction resulting in hypertension or hypotension. Resting hypotension and OH in upper SCI patients occurs due to impairment of sympathetic cardiovascular inputs, which leaves vagally mediated parasympathetic pathways unopposed. In one study, nearly 75% of SCI patients demonstrated OH during postural changes, but fewer than 60% of individuals were symptomatic. Pre-syncopal episodes are disruptive to daily activities, can limit participation in rehabilitation, and pose a fall risk during positional transfers. Unaddressed, dramatic blood pressure fluctuations may also contribute to long-term cognitive impairment in SCI patients through effects on cerebral vasculature. A recent systematic review found that among pharmacologic agents used to control OH in SCI patients, only midodrine, a selective alpha-adrenergic agonist, had evidence from a randomized controlled trial (pilot study, n=4) to support its use. Outpatient practitioners can initiate midodrine at low doses (2.5 or 5 mg in the morning and afternoon) and rapidly uptitrate. Twice daily dosing may be preferable to avoid an evening dose, which can predispose patients to supine hypertension. Home blood pressure monitoring complements subjective reporting of symptoms. Fludrocortisone, a mineralocorticoid, is commonly initiated prior to midodrine for management of OH in general, but its use lacks rigorous evidence in SCI patients specifically. Physical interventions such as abdominal binders, compression stockings, and increased fluid and salt intake are also common but lack specific evidence in SCI patients.