Spinal epidural hematoma (SEH) is a collection of blood in the epidural space (between dura mater and periosteum) of the spinal canal. It can develop spontaneously (patients on anticoagulant therapy, coagulopathy, thrombocytopenia), traumatically (vertebral fracture, ligament injury), or iatrogenically (following epidural anesthesia, lumbar puncture, or spinal surgery). The venous plexus (Batson's plexus) within the epidural space is the most susceptible structure for bleeding — being a valveless venous system, changes in abdominal/thoracic pressure increase hematoma risk. The posterior epidural space is affected far more frequently than the anterior space because the posterior internal vertebral venous plexus is more developed here. SEH typically extends across multiple vertebral segments and shows biconvex/lenticular morphology — this feature is important in distinguishing epidural from subdural hematoma. MRI is the gold standard for diagnosis; T1/T2 signal intensity varies with hematoma age — this variability reflects the hemoglobin degradation process (oxy → deoxy → methemoglobin → hemosiderin). In acute SEH with cord compression findings, neurosurgical emergency intervention is required; performing surgical decompression (laminectomy) within the first 6-12 hours significantly improves functional recovery.
Age Range
30-80
Peak Age
60
Gender
Male predominant
Prevalence
Rare
The pathophysiology of spinal epidural hematoma is directly related to vascular structures in the epidural space. The posterior internal vertebral venous plexus (Batson's plexus) is the most developed vascular structure of the epidural space — being valveless, this plexus is directly exposed to changes in abdominal and thoracic pressure (coughing, straining, Valsalva). Pressure increase can cause rupture of the venous plexus wall → bleeding into the epidural space. Anticoagulant therapy (warfarin, heparin, DOACs) inhibits the coagulation cascade increasing bleeding tendency → most common cause of spontaneous SEH. The hematoma created by acute bleeding accumulates within epidural fat tissue and assumes a biconvex shape — this results from the natural boundaries of the potential space between dura mater and periosteum. As the hematoma expands, it compresses the spinal cord → neuronal ischemia and edema → rapidly progressive neurological deficit. Hemoglobin degradation forms the basis of time-dependent MR signal changes: in the hyperacute phase (0-6 hours) oxyhemoglobin gives iso T1 and hyper T2 signal; in the acute phase (6-72 hours) deoxyhemoglobin shortens T2 → T2 hypointensity; in the early subacute phase (3-7 days) intracellular methemoglobin shortens T1 through paramagnetic effect → T1 hyperintensity develops (most diagnostic phase); in the late subacute phase (1-4 weeks) extracellular methemoglobin gives hyperintense signal on both T1 and T2; in the chronic phase hemosiderin deposition → marked hypointensity on T2 and especially GRE/SWI.
Collection in the posterior epidural space with biconvex morphology showing hyperintense signal on T1-weighted images — the signature finding of subacute spinal epidural hematoma. T1 hyperintensity results from the paramagnetic effect of intracellular/extracellular methemoglobin and indicates the hematoma is in the 3-day to 4-week time window. The combination of posterior location + biconvex shape + T1 hyperintensity + no enhancement distinguishes epidural hematoma from other epidural collections (abscess, metastatic deposit, lipomatosis) with high confidence.
T1 signal intensity of spinal epidural hematoma varies with hematoma age. Hyperacute phase (0-6 hours): oxyhemoglobin → T1 isointense (similar signal to muscle). Acute phase (6-72 hours): deoxyhemoglobin → T1 isointense to mildly hyperintense. Early subacute phase (3-7 days): intracellular methemoglobin → T1 markedly hyperintense — most diagnostic phase, hematoma brightness is clearly distinguishable from surrounding structures. Late subacute phase (1-4 weeks): extracellular methemoglobin → T1 remains hyperintense. Chronic phase (>4 weeks): hemosiderin → T1 mildly hypointense or isointense, peripheral hemosiderin rim. Biconvex morphology in the posterior epidural space and craniocaudal extent of the epidural collection are evaluated on sagittal and axial T1 images.
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Biconvex epidural collection in the posterior epidural space extending across ___ vertebral segments, showing hyperintense signal on T1-weighted images, consistent with subacute epidural hematoma.
Signal of epidural hematoma on T2-weighted images is variable with hematoma age and shows a more complex pattern than T1. Hyperacute phase: oxyhemoglobin → T2 hyperintense (water-like signal). Acute phase: deoxyhemoglobin → T2 markedly hypointense (susceptibility effect) — this phase is the most valuable T2 finding for detecting hematoma. Early subacute phase: intracellular methemoglobin → T2 hypointense (susceptibility effect persists). Late subacute phase: cell lysis causes methemoglobin to become extracellular → T2 hyperintense. Chronic phase: hemosiderin → T2 markedly hypointense rim + central heterogeneous signal. In the acute phase, T2 hypointensity creates contrast with cord edema (T2 hyperintense) making the hematoma conspicuous.
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The epidural collection shows heterogeneous signal intensity on T2-weighted images with time-dependent signal changes consistent with the age of hematoma.
Acute spinal epidural hematoma appears as a hyperdense collection (50-70 HU) on non-contrast CT. Biconvex morphology in the posterior epidural space and anterior displacement of the spinal cord are characteristic. The high protein density of acute blood products creates the hyperdensity. In subacute and chronic phases, density progressively decreases (isodense → hypodense). CT is also superior to MRI in evaluating accompanying vertebral fractures (in traumatic cases) and bone fragments. However, MRI is the gold standard for cord compression assessment and hematoma staging.
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Hyperdense (__ HU) biconvex collection at ___ level in the posterior epidural space on non-contrast CT, consistent with acute epidural hematoma; spinal cord is displaced anteriorly.
Spinal epidural hematoma shows no enhancement or minimal peripheral enhancement on contrast-enhanced MRI. Absence of enhancement is the most important criterion in distinguishing hematoma from infectious collections (epidural abscess): epidural abscess shows marked rim enhancement and diffusion restriction, while hematoma does not enhance. Peripheral granulation tissue may develop in subacute/chronic hematomas → thin rim enhancement — this may cause confusion with abscess. Clinical correlation (fever, leukocytosis vs anticoagulant use) is critical in differential diagnosis.
Report Sentence
The epidural collection shows no enhancement on contrast-enhanced series, supporting differentiation from infectious collection (abscess); consistent with hematoma.
Spinal epidural hematoma typically shows no diffusion restriction on DWI — ADC values are high. This finding is an important supplementary criterion complementing T1/T2 signal changes in differentiating from epidural abscess: abscess shows marked diffusion restriction and low ADC in purulent content (high viscosity, cellularity), while hematoma does not. However, intact erythrocytes in hyperacute/acute hematoma may create T2 shine-through artifact → false hyperintensity on DWI; true restriction must be excluded with ADC map.
Report Sentence
No significant diffusion restriction is observed in the epidural collection on DWI, reducing the likelihood of abscess and supporting the diagnosis of hematoma.
Criteria
Hematoma developing without trauma or interventional procedure. Most commonly under anticoagulant therapy (warfarin, DOAC, heparin). Coagulopathy, thrombocytopenia, vascular malformation also in etiology.
Distinct Features
Thoracic and thoracolumbar region most commonly affected. Posterior epidural location common. Extension across multiple segments. Acute onset severe back pain followed by rapidly progressive neurological deficit is typical presentation.
Criteria
Hematoma developing after spinal trauma (vertebral fracture, ligament injury). Cervical and thoracolumbar region common.
Distinct Features
May be accompanied by vertebral fracture, posterior ligament complex injury, or spinal instability. Bone pathology assessment with CT is critical. Surgical planning may include both hematoma drainage and stabilization.
Criteria
Hematoma developing after spinal procedure: epidural anesthesia, lumbar puncture, spinal surgery, epidural steroid injection.
Distinct Features
Location near procedure site. Usually lumbar or lower thoracic region. Postoperative neurological deterioration is a red flag — should be evaluated with emergent MRI. Risk significantly increased in patients on anticoagulants.
Distinguishing Feature
Arachnoid cyst is isointense to CSF on all sequences with no enhancement; epidural hematoma shows time-dependent T1/T2 signal changes (T1 hyperintense in subacute phase). Arachnoid cyst shows no DWI restriction while hematoma may show T2 shine-through. Clinical: hematoma has acute onset, cyst usually chronic/asymptomatic.
Distinguishing Feature
Tarlov cyst is a perineural cyst at CSF density in the sacral region with nerve root identified within cyst wall; epidural hematoma shows signal varying with hemoglobin degradation in the posterior epidural space. Tarlov cyst does not enhance and is incidental; hematoma shows acute presentation.
Distinguishing Feature
Tethered cord syndrome is a congenital anomaly characterized by low conus position and thick/fatty filum terminale; epidural hematoma is an acquired epidural collection. T1 hyperintensity in tethered cord is from fat signal (suppresses on fat-sat); in hematoma from methemoglobin (does not suppress on fat-sat).
Urgency
emergentManagement
surgicalBiopsy
Not NeededFollow-up
specialist-referralSpinal epidural hematoma is a neurosurgical emergency — cord compression can cause permanent neurological damage (paraplegia, quadriplegia, sphincter dysfunction). Emergent surgical decompression (laminectomy + hematoma evacuation) should be performed within the first 6-12 hours; after 12 hours, chance of complete functional recovery drops dramatically. In anticoagulated patients, INR must be urgently corrected (vitamin K, fresh frozen plasma, prothrombin complex concentrate). Conservative management (anticoagulant cessation + close neurological monitoring) may be chosen for small hematomas with mild neurological symptoms; however, preparation for emergent surgery must be made if neurological progression occurs. Post-operative MRI is recommended to evaluate residual hematoma and cord compression.
Spinal epidural hematoma is a neurological emergency. Rapidly progressive cord compression can cause permanent neurological damage. Emergent surgical decompression (laminectomy) should be performed within the first 6-12 hours — delay increases paralysis risk. In anticoagulated patients, INR must be corrected. Underlying coagulopathy should be investigated in spontaneous cases.