Subdural Hematoma

Subdural Hematoma Definition Haemorrhage at the subdural space – between dura matter and arachnoid matter Caused by rupture of bridging veins Epidemiology Three times more common in males Classifications Type Description Acute Symptoms manifest within 3 days of causative event Subacute Symptoms manifest within 4 to 20 days of causative event Chronic Symptoms manifest at 21 or more days of causative event Causes Acute Chronic non-traumatic Chronic non-traumatic Adults – cerebral atrophy Advanced age Alcohol use disorder Neurodegenerative disease e.g. AD, HIV dementia Blunt head trauma Chronic DM Most common Previous traumatic brin injury Mild trauma secondary to falls Cerebral irradiation Infants Infants and young children Birth trauma Meningitis Non-accidental – birth trauma From high energy MVA Nonaccidental trauma Shaken baby syndrome Acceleration-deceleration injury Both Haemodialysis Arteriolosclerosis Intracranial tumours Hypertension Key Info May occur even after trivial trauma in patients who have multiple RFs Pathophysiology RFs/causes bridging veins rupture low P venous bleeding into subdural space Clinical features Acute Rapid progression Can progress to cerebral herniation and death Impaired level of consciousness Confusion Rapid deterioration to a coma Focal neurological signs Adults C/L hemiparesis and UMN signs I/L hemiparesis due to Kernohan’s syndrome CN palsies Diplopia Blurred vision Unequal pupils Anosmia Slurred and disorganised speech Pupillary abnormalities Anisocoria U/L or B/L fixed dilated pupils Features of raised ICP Headache Vomit Cushing triad Features of cerebral herniation Abnormal posture Decorticated posture Decerebrate posture Seizures Subacute Can be acute or insidious If there is a rebleed rapid neurological decline Mixture of acute and chronic features Chronic Insidious symptom onset Gradual progression AMS coma Confusion Delirium Drowsiness Recurrent headaches Cognitive deficits Impaired memory Dementia Focal neurological signs C/L hemiparesis (most common) may progress into hemiplegia Incontinence Ataxia Recurrent falls Changes in personality Seizures rare Investigations Head CT without IV contrast First line Findings: Cresent-shape Mass effect midline shift and ventricle effacement Often cross suture lines Radiodensities vary based on time since causative event: Acute hyperdense Subacute isodense Chronic hypodense MRI Neurological features not explained by CT Findings similar to ST Angiography To determine the cause of a nontraumatic SDH Modalities: CTA MR angiography DSA DDx Epidural hematoma SAH ICH Stroke Brain tumour Meningitis Management Depend on size, neurological status at presentation ad cause ABCDE assessment If on anticoagulation reverse Symptomatic patients Neuroprotective measures Empiric management for ICP Asymptomatic Neurosurgery consult for surgical vs conservative management Conservative management Indications Asymptomatic Hematoma less than 10 mm Midline shift less than 5 mm Normal pupillary reflex and no features of raised ICP Regardless of GCS Neurosurgery interventions Indications Hematoma of 10 mm or more Midline shift of 5 mm or more Features of cerebral herniation Rapid neurological deterioration two more decrease in GCS from injury or symptom onset to ED presentation U/L or B/L fixed dilated pupils ICP more than 20 mmHg Failure of conservative management Options Craniotomy with hematoma evacuation Decompressive craniectomy Complications Neurological deterioration Most common complication Brain herniation Permanent brain injury and disability Seizures Stroke/vascular damage Death Recurrence Surgical complications