A spinal subdural hematoma (SSDH) is a rare accumulation of blood in the space between two of the protective layers covering the spinal cord—the dura mater and the arachnoid mater. The buildup of blood can compress the spinal cord and nerve roots, leading to a range of neurological problems. This condition is considered a neurological emergency, as the pressure it creates can disrupt normal nerve function.
Causes and Risk Factors
The origins of a spinal subdural hematoma fall into two categories: traumatic and spontaneous. Traumatic injuries are a frequent source, often occurring as a complication of procedures involving the spine. These include lumbar punctures, where a needle is inserted into the spinal canal, as well as the administration of epidural anesthesia. Direct trauma to the back from an accident or fall can also tear blood vessels and lead to a hematoma.
Spontaneous hematomas occur without a preceding injury and are often linked to underlying health issues. Patients with blood clotting disorders (coagulopathies) have a heightened risk. The use of anticoagulant medications, or blood thinners, similarly increases the likelihood of bleeding. Abnormalities in the blood vessels within the spinal canal, such as arteriovenous malformations, can also rupture and bleed into the subdural space.
Recognizing the Symptoms
The signs of a spinal subdural hematoma can manifest suddenly or develop more gradually over several days. The most common initial symptom is severe and localized back pain that is persistent and does not get better with rest. As the hematoma expands and exerts more pressure on the spinal cord, additional neurological symptoms emerge.
This progression can lead to radicular pain, which is pain that travels from the spine down into the arms or legs along the path of a compressed nerve root. Patients may also experience progressive weakness, numbness, or tingling sensations in their limbs, making activities like walking difficult. In the most severe cases, significant compression of the lower spinal cord can result in a condition called cauda equina syndrome. This syndrome involves loss of bowel or bladder control, numbness in the groin area, and significant leg weakness.
The Diagnostic Process
When a spinal subdural hematoma is suspected, imaging tests are required to confirm the diagnosis. The most effective and widely used diagnostic tool is Magnetic Resonance Imaging (MRI). An MRI uses powerful magnets and radio waves to create detailed, cross-sectional images of the spine, allowing doctors to see the spinal cord, surrounding tissues, and the location and size of the blood collection.
If an MRI is not available or cannot be performed, Computed Tomography (CT) myelography may be used as an alternative. This procedure involves injecting a special contrast dye into the spinal canal before taking a CT scan. The dye helps to outline the spinal cord and nerve roots, making it possible to identify the hematoma and the extent of the compression it is causing.
Treatment Approaches
The strategy for treating a spinal subdural hematoma depends heavily on the patient’s symptoms and the size of the hematoma. For individuals with very small hematomas and mild or no neurological deficits, a conservative approach may be chosen. This involves careful monitoring of the patient’s condition to see if the body will reabsorb the blood on its own over time.
When the hematoma is large or causes significant and progressive neurological problems, surgical intervention is typically necessary. The standard surgical procedure is a laminectomy with hematoma evacuation. During this operation, a surgeon removes a small portion of the bony arch of a vertebra, called the lamina, to gain access to the subdural space. Once accessed, the collected blood is carefully drained to relieve pressure on the spinal cord. Timely decompression is performed to prevent permanent nerve damage.
Recovery and Outlook
The prognosis for individuals with a spinal subdural hematoma is generally favorable, especially when the condition is identified and treated quickly. A factor influencing the outcome is the patient’s neurological condition just before treatment begins. Those who have mild deficits and receive prompt medical care tend to have a more complete recovery. The duration of symptoms before intervention also plays a part; shorter symptom duration is associated with better results.
Following treatment, particularly surgery, physical therapy is a common component of the recovery process. Rehabilitation helps patients regain muscle strength, improve coordination, and restore function that may have been affected by the spinal cord compression.