Awakening Blood Pressure Rise in a Patient with Spinal Cord Injury

Postprandial Hypotension and Spinal Cord Injury

Postprandial hypotension (PPH) is defined as a fall of ≥20 mmHg in systolic blood pressure (SBP) or a SBP of <90 mmHg after having been >100 mmHg before the meal within two hours after a meal. The prevalence of PPH among persons with spinal cord injury (SCI) is unknown. Ambulatory blood pressure measurement was performed in 158 persons with SCI, 109 men, median age was 59.1 years (min.:13.2; max.: 86.2). In total, 78 persons (49.4%) had PPH after 114 out of 449 meals (25.4%). The median change in SBP during PPH was −28 mmHg (min.: −87; max.: −15 mmHg) and 96% of the PPH episodes were asymptomatic. The occurrence of PPH was correlated to older age (p = 0.001), level of injury (p = 0.023), and complete SCI (p = 0.000), but not, gender or time since injury. Further studies are needed to elucidate if PPH contributes to the increased cardiovascular mortality in the SCI population.

Cardiovascular Autonomic Dysfunction in Spinal Cord Injury: Epidemiology, Diagnosis, and Management

Spinal cord injury (SCI) disrupts autonomic circuits and impairs synchronistic functioning of the autonomic nervous system, leading to inadequate cardiovascular regulation. Individuals with SCI, particularly at or above the sixth thoracic vertebral level (T6), often have impaired regulation of sympathetic vasoconstriction of the peripheral vasculature and the splanchnic circulation, and diminished control of heart rate and cardiac output. In addition, impaired descending sympathetic control results in changes in circulating levels of plasma catecholamines, which can have a profound effect on cardiovascular function. Although individuals with lesions below T6 often have normal resting blood pressures, there is evidence of increases in resting heart rate and inadequate cardiovascular response to autonomic provocations such as the head-up tilt and cold face tests. This manuscript reviews the prevalence of cardiovascular disorders given the level, duration and severity of SCI, the clinical presentation, diagnostic workup, short- and long-term consequences, and empirical evidence supporting management strategies to treat cardiovascular dysfunction following a SCI.

A case of postprandial hypotension in an individual with cervical spinal cord injury: treatment with acarbose

Introduction

Postprandial hypotension (PPH) is a postmeal drop in systolic blood pressure that may or may not be symptomatic. While the etiologies of PPH are incompletely understood, it is thought to occur when glucose absorption causes increased splanchnic blood flow or "pooling" in people who lack sufficient compensatory responses to support their systemic blood pressure. Postprandial hypotension is well described in individuals with neurodegenerative diseases, yet only rarely in people living with spinal cord injury (SCI). Acarbose is an alpha-glucosidase inhibitor that treats PPH by slowing gastric transit time and reducing glucose uptake in the small intestine, hence decreasing superior mesenteric artery blood flow.

Case presentation

A 62-year-old woman with long-standing cervical SCI presented with 5 years of worsening postprandial lightheadedness, visual "flashes", and neck pain. She had had multiple episodes of near and frank syncope and her prior medical team had initiated midodrine three times daily. We began treatment with acarbose, starting at 50 mg with each meal and rapidly titrating to 100 mg at mealtime. She noticed an immediate improvement in her symptoms and an attenuation of postmeal drops in both systolic and diastolic blood pressures.

Discussion

To our knowledge, this is one of the first described cases of PPH among people living with SCI. Given the autonomic dysfunction that frequently accompanies higher-level of injuries, it is possible that many more people with SCI have this condition, whether or not it is symptomatic. Acarbose is one of the several established treatments for PPH, and proved effective and tolerable for our patient.