Subarachnoid Hemorrhage: Understanding Common Complications and Their Impact on Recovery

Subarachnoid hemorrhage (SAH) is a life-threatening type of stroke that occurs when bleeding happens in the space between the brain and the surrounding membrane. While immediate medical intervention is crucial, long-term outcomes are often influenced by several potential complications that can arise in the days and weeks following the initial event.

1. Cerebral Vasospasm: A Major Post-Bleeding Threat

One of the most serious and frequent complications after subarachnoid hemorrhage is cerebral vasospasm. This condition develops when blood released into the subarachnoid space irritates the cerebral arteries, causing them to constrict abnormally. The narrowing of these vital blood vessels reduces blood flow to critical areas of the brain, potentially leading to delayed cerebral ischemia or even infarction.

Symptoms of vasospasm may include confusion, decreased level of consciousness, weakness on one side of the body, or speech difficulties—often appearing 4 to 14 days post-hemorrhage. To mitigate this risk, clinicians routinely administer calcium channel blockers like nimodipine, which has been shown to improve neurological outcomes by preventing vasospasm and enhancing cerebral perfusion.

Preventive Strategies and Monitoring

Patients are closely monitored using transcranial Doppler ultrasound and CT angiography to detect early signs of vessel narrowing. In severe cases, endovascular treatments such as intra-arterial vasodilator infusion or balloon angioplasty may be required to restore proper blood flow.

2. Risk of Rebleeding: A Critical Early Danger

Another major concern, especially within the first 24 to 72 hours after the initial bleed, is the risk of rebleeding. Most spontaneous subarachnoid hemorrhages are caused by the rupture of an intracranial aneurysm—an abnormal bulge in a brain artery wall. If left untreated, the same aneurysm can rupture again, leading to a sudden worsening of symptoms and a significantly higher mortality rate.

Studies show that the risk of rebleeding can exceed 15% within the first two weeks, making prompt diagnosis and treatment essential. Modern interventions such as endovascular coiling or surgical clipping are typically performed early to secure the aneurysm and prevent future bleeding episodes.

3. Hydrocephalus: Disruption of Cerebrospinal Fluid Dynamics

Hydrocephalus is another common complication following SAH, affecting up to 20–30% of patients. It occurs when blood components block the arachnoid granulations—tiny structures responsible for absorbing cerebrospinal fluid (CSF) into the bloodstream. This obstruction impairs normal CSF reabsorption, leading to its accumulation and subsequent enlargement of the brain's ventricles.

Types and Treatment Approaches

Acute hydrocephalus may develop rapidly and require urgent intervention, such as the placement of an external ventricular drain (EVD) to relieve pressure. In contrast, chronic hydrocephalus might appear weeks later, with symptoms like gait instability, cognitive decline, and urinary incontinence—often referred to as "normal pressure hydrocephalus" (NPH).

In persistent cases, a permanent solution like a ventriculoperitoneal (VP) shunt may be necessary to ensure continuous drainage and protect brain function.

Overall, managing subarachnoid hemorrhage goes beyond controlling the initial bleed. Recognizing and proactively treating complications like vasospasm, rebleeding, and hydrocephalus plays a pivotal role in improving survival rates and enhancing long-term recovery. Multidisciplinary care involving neurologists, neurosurgeons, and intensive care specialists is key to optimizing patient outcomes in these complex cases.