Makindo Medical Notes.com

Related Subjects: |Traumatic Head/Brain Injury |Epidural Haematoma |Brain Herniation syndromes |Subdural haematoma

An accumulation of blood between the dura and the arachnoid membrane usually related to trauma +/- anticoagulation. They can be bilateral. Also ensure you don't miss any trauma associated C-spine fractures

About

• Tear of bridging veins caused by acceleration - deceleration injury
• A cause of altered mental status from delirium to coma
• If any concern then CT head +/- cervical spine

Top Tips

• SDH blood can be isodense to brain parenchyma and missed
• Surgeons prefer to allow the blood to liquefy and remove via burr holes

Large left acute + subacute SDH with midline shift

Aetiology

• Rupture of bridging veins crossing subdural space
• Worsening with cerebral atrophy and increasing shear forces
• Head injury is the commonest cause and may be very subtle or not recalled
• Other factors are Chronic alcohol abuse and Anticoagulant therapy
• Usually associated with mild to severe trauma
• Increased ICP can compress the thalamus and brainstem

Causes

• Falls and trauma, Trauma and assaults in young patients
• Anticoagulants, Elderly patients, Alcohol abuse
• Low CSF pressure after an LP

Clinical

• Can be acute with fall in GCS and coning or mild with delirium
• Headache, unsteadiness, contralateral hemiparesis or hemisensory loss
• Fixed dilated pupils - IIIrd nerve palsy suggests herniation
• Seizures, Drowsiness, Delirium
• Reduced GCS, Cheyne-Stokes respiration,
• Non convulsive and convulsive status

Investigations

• Check INR or coagulation screen especially if on Warfarin or liver disease
• Non-contrast CT: shows a rim of hyperdense crescent-shaped extra axial blood which over time gradually has density of brain and then CSF. There may be midline shift and signs of raised ICP. Sometimes they can be very subtle and easily missed - see only be closely inspecting the space between cortex and inner skull.
• CT Cervical spine if concerns of spinal fracture especially if patient unconscious
• MRI scan can be helpful if suspected that subdural isodense with the brain on CT

Complications

• Recurrent haematomas
• Infection (subdural empyema)
• Seizures often focal and contralateral initially
• Raised ICP and coning
• Contralateral ACA stroke as artery gets nipped by the falx

Management

• ABC and acute assessment. Neurosurgical referral. Reverse any coagulopathy. Ensure platelets are > 100 x 10⁹/L.
• Anticonvulsants may be started acutely for a period of time. Some patients may need HDU/ITU and airway issues if GCS < 8
• Discuss with local neurosurgeons. Small subdurals managed conservatively. Larger haematomas need surgical removal with trauma craniotomy. Larger ones may ned hemicrainiectomy.
• Those with chronic rather than acute bleeds do better. Recommendations to evacuate all with a rim > 10 mm or midline shift > 5 mm.
• Over time acute SDH can become chronic with recurring bleeding and it may take 3 months or so for things to settle. With chronic SDH the management is with burrholes as the usually jelly-like clot has liquefied and can be more easily aspirated without craniotomy.
• In many frail cases management may be palliative where the patient i evidently dying with signs of raised ICP