Ischemia, Immunosuppression and Infection--Tackling the Predicaments of Post-Stroke Complications

The incidence of stroke has risen over the past decade and will continue to be one of the leading causes of death and disability worldwide. While a large portion of immediate death following stroke is due to cerebral infarction and neurological complications, the most common medical complication in stroke patients is infection. In fact, infections, such as pneumonia and urinary tract infections, greatly worsen the clinical outcome of stroke patients. Recent evidence suggests that the disrupted interplay between the central nervous system and immune system contributes to the development of infection after stroke. The suppression of systemic immunity by the nervous system is thought to protect the brain from further inflammatory insult, yet this comes at the cost of increased susceptibility to infection after stroke. To improve patient outcome, there have been attempts to lessen the stroke-associated bacterial burden through the prophylactic use of broad-spectrum antibiotics. However, preventative antibiotic treatments have been unsuccessful, and therefore have been discouraged. Additionally, with the ever-rising obstacle of antibiotic-resistance, future therapeutic options to reverse immune impairment after stroke by augmentation of host immunity may be a viable alternative option. However, cautionary steps are required to ensure that collateral ischemic damage caused by cerebral inflammation remains minimal.