What are intramedullary hematomas?

Intramedullary Hematomas: Clinical Features and Management

Intramedullary hematomas are collections of blood that occur within the medullary cavity of a bone or within the substance of the spinal cord, presenting with distinct clinical manifestations and requiring prompt diagnosis and management to prevent significant morbidity and mortality.

Types of Intramedullary Hematomas

There are two distinct types of intramedullary hematomas, which differ significantly in their location, presentation, and management:

1. Intramedullary Spinal Cord Hematomas (Hematomyelia)

• Definition: Bleeding that occurs within the substance of the spinal cord

• Clinical Presentation:

  • Sudden, severe back or neck pain
  • Radicular pain
  • Rapid development of myelopathy syndrome (transverse, central, anterior, posterior, or hemi-cord) 1
  • Neurological deficits corresponding to the level of the lesion
  • Can present in acute, subacute, stepwise, or chronic fashion

• Etiology:

  • Spinal vascular malformations (most common cause)
    • Intramedullary cavernomas
    • Intradural arteriovenous malformations
  • Anticoagulation therapy (warfarin or heparin)
  • Hereditary or acquired bleeding disorders
  • Primary spinal cord tumors or metastases
  • Gowers' intrasyringal hemorrhage
  • Delayed complication of spinal radiation 1
  • Trauma

• Diagnosis:

  • MRI with and without gadolinium is the preferred imaging modality 1
  • CT angiography may be used to evaluate vascular abnormalities 2

• Management:

  • Emergency surgical decompression and hematoma removal for acute cases with neurological deficits 3
  • Treatment directed toward the underlying cause

2. Intramedullary Bone Hematomas

• Definition: Bleeding that occurs within the medullary cavity of long bones

• Clinical Presentation:

  • Pain without external swelling
  • No history of trauma in spontaneous cases 4
  • May be associated with bleeding disorders

• Etiology:

  • Congenital bleeding disorders (e.g., alpha-2-plasmin inhibitor deficiency) 5, 4
  • Pathologic fractures from metastatic disease 2
  • Trauma

• Diagnosis:

  • X-rays show hyperlucent lesion without sclerotic edges in the medulla with possible cortical thinning
  • MRI is diagnostic, showing hyperintense signal on both T1-weighted and T2-weighted images 4

• Management:

  • Treatment of underlying bleeding disorder
  • Surgical intervention may be required in certain cases
  • Antifibrinolytic agents like tranexamic acid can be used for hemostatic management in patients with bleeding disorders 5

Diagnostic Approach

1. Clinical Assessment:

   • Evaluate for pain pattern, neurological deficits, and history of trauma or bleeding disorders
   • For spinal cord hematomas, assess for myelopathy syndromes
   • For bone hematomas, assess for localized pain without swelling

2. Imaging:

   • Spinal Cord Hematomas: MRI spine without and with contrast is the gold standard 1
   • Bone Hematomas: X-rays followed by MRI for definitive diagnosis 4
   • CT may be used to evaluate for associated fractures 2

Management Considerations

For Spinal Cord Hematomas:

• Urgent surgical decompression for cases with progressive neurological deficits 3
• Careful monitoring of neurological status
• Reversal of anticoagulation if applicable
• Treatment of underlying vascular malformations or tumors

For Intramedullary Bone Hematomas:

• Treatment of underlying bleeding disorder if present

• Surgical intervention may be required for:

  • Persistent pain
  • Risk of pathological fracture
  • When associated with metastatic disease 2

• For patients with bleeding disorders undergoing surgery:

  • Use of antifibrinolytic agents like tranexamic acid 5
  • Careful hemostatic management

Special Considerations

1. Misdiagnosis Risk: Thoracic intramedullary spinal hematomas can present with chest pain that mimics myocardial infarction, pulmonary embolism, or aortic dissection 3

2. Pathologic Fractures: When intramedullary hematomas are associated with metastatic disease, assessment should include:

   • Evaluation of life expectancy
   • Mental status
   • Mobility status
   • Pain level
   • Metabolic status
   • Skin condition
   • Nutritional status 2

3. Surgical Approach for Pathologic Cases:

   • Intramedullary nailing is generally preferred for long bone metastatic disease 2
   • For proximal femur and humerus, long-stem cemented or modular tumor endoprosthesis is preferred 2

Pitfalls and Caveats

1. Delayed Diagnosis: Symptoms of high thoracic intramedullary hematomas can mimic cardiac conditions, leading to delayed diagnosis and inappropriate treatment (e.g., anticoagulation) 3

2. Anticoagulation Risk: Patients on anticoagulants who develop spinal cord hematomas may experience worsening of bleeding if the diagnosis is missed

3. Surgical Timing: For pathologic fractures, prophylactic stabilization of impending fractures is generally preferred to fixation after fracture as functional recovery is better 2

4. Imaging Interpretation: Intramedullary bone hematomas may be confused with other lytic bone lesions on plain radiographs, making MRI essential for accurate diagnosis

Early recognition and appropriate management of intramedullary hematomas are crucial to minimize morbidity and improve outcomes, particularly for spinal cord hematomas where rapid surgical intervention can significantly affect prognosis.