Spinal subdural haematoma due to traumatic brain injury

A healthy 16-year-old boxer consults the emergency room after facial trauma, lipothymia and seizures. The neurological exam was normal. A brain scan reported acute subdural haematoma. He was admitted, observed and discharged. Four days later, he reconsults due to bilateral leg pain and gait disorder. A brain scan and spinal MRI were requested for study.

The second brain computed tomography (CT) showed a left supratentorial chronic subdural haematoma and a right laminar parafalcine subdural haematoma.

The MRI of the spinal cord showed an intradural collection, hyperintense in T1 signal and hypointense in T2 sequence, consistent with early subacute haemorrhage. The location is predominantly the posterior lumbar extending from T12 to the sacrum, with concentric content in the lumbosacral cuff that determines compression of the roots of the cauda equina. The spinal cord demonstrated normal thickness and signal with a normally situated medullary cone.

Conclusion: Posterior lumbar subdural haematoma from T12 to the sacrum, with concentric lumbosacral distribution that determines compression of the thecal sac and roots.

Spinal subdural haematoma (SSH) is defined as blood accumulation in the subdural space, between the dura mater and arachnoid layer. It is less frequent than epidural haematomas, representing up to 4% of all spinal haematomas. The most common location is within the thoracic spine, and the main causes are anticoagulation treatments, coagulopathies, vascular spinal malformations, percutaneous spinal intervention and, rarely, trauma [1]. Pathophysiology is unknown, but it is suggested to be secondary to the migration of blood from the intracranial space [2].

The main manifestations of SSH are back and radicular pain, often associated with hypoesthesia and muscular weakness [3]. Nevertheless, this may vary depending on the spinal level. Progression of the haematoma can lead to spinal cord compression or cauda equina syndrome, manifesting itself as saddle anaesthesia and sphincter dysfunction. Other symptoms should be evaluated considering differential diagnoses, such as fever orienting to spinal abscess. Nevertheless, some entities like hygromas and epidural haematomas have the same clinic and can only be recognised with imaging, highlighting their value for diagnosis.

CT is usually the first choice in the emergency room, but it has the inconvenience that it does not detect small haematomas. Nevertheless, MRI is considered the gold standard for assessing spinal lesions. The characterisation of the tissue varies with blood ageing [3,4]: Hyperacute bleeding is isointense in both T1 and T2; Acute bleeding progresses to T1 and T2 hypointense; Early subacute bleeding in T1 becomes hyperintense, and T2 signal increases gradually on late subacute timing; Finally, in chronic phase, T1 and T2 both become hypointense. Furthermore, MRI helps to distinguish subdural from epidural haematoma, as epidural collections exert a mass effect displacing fat and dural sac inwards, while subdural masses do not have this behaviour. Also, there is a characteristic sign of blood casing around arachnoid lines, known as “inverted Mercedes–Benz sign”, which is highly suggestive for SSH [1].

The main therapeutic option consists of surgical laminectomy with clot drainage and is usually recommended in cases of significant neurological deficit, cauda equina syndrome, and cervical or thoracic locations, due to its worse prognosis than lower sites [1]. Conservative management with serial follow-up with MRI can be considered if the neurologic deficits are mild or decreasing, and haematomas are small [5]. In this case, the neurosurgeons decided on surgical drainage and decompression due to progressive clinical deterioration.

Written informed patient consent for publication has been obtained.