What are the typical acute and chronic symptoms and clinical presentation of subdural hematoma, particularly in older adults or patients on anticoagulant therapy?

Subdural Hematoma: Clinical Presentation and Symptoms

Acute Subdural Hematoma Presentation

Acute subdural hematoma typically presents with rapid neurological deterioration over minutes to hours, characterized by headache, altered consciousness, focal neurological deficits (motor weakness, sensory changes, speech disturbance), and potentially coma—with severity correlating to hematoma size and patient age. 1

Cardinal Acute Symptoms

• Sudden focal neurological deficit that progresses smoothly over minutes to hours while the patient is active—this smooth symptomatic progression is uncommon in ischemic stroke 2
• Headache is more common with subdural hematoma than with ischemic stroke, though less common than in subarachnoid hemorrhage 2
• Vomiting occurs more frequently than in either ischemic stroke or subarachnoid hemorrhage 2
• Elevated blood pressure and impaired level of consciousness are common presenting features 2
• Signs of raised intracranial pressure including severe headache, vomiting, and rapid neurological deterioration 1

Neurological Examination Findings

• Glasgow Coma Scale (GCS) score is the most powerful predictor of 30-day mortality, along with hematoma volume 2
• Pupillary abnormalities (anisocoria or bilateral mydriasis) indicate herniation risk and constitute an absolute indication for immediate surgical evacuation 1
• Focal motor deficits such as hemiplegia or weakness indicate significant mass effect or underlying brain injury 3

Subacute Subdural Hematoma Presentation (7-21 Days Post-Injury)

Subacute subdural hematomas are particularly dangerous because they demonstrate acute neurological worsening within hours during the second week after injury, distinguishing them from the more gradual deterioration seen in chronic hematomas. 4

Key Clinical Features

• Rapid neurological deterioration typically occurs during the second week post-injury, with acute worsening within hours 4
• Iso-density appearance on CT in a young person is a predictive factor for rapid neurological aggravation requiring urgent care 4
• Mean time to symptom onset is approximately 13.8 days after trauma in subacute cases 5
• Higher mortality risk compared to chronic subdural hematomas, with deaths occurring even in patients awaiting surgery 4

Chronic Subdural Hematoma Presentation (>21 Days Post-Injury)

Chronic subdural hematomas present with progressive, gradual neurological deterioration rather than acute worsening, commonly manifesting as altered mental status, focal neurological deficits, and headache—particularly in elderly patients. 6

Typical Chronic Symptoms

• Altered mental status is the most common presenting symptom 6
• Focal neurological deficits develop gradually over weeks 6
• Headache that is persistent but less acute than in acute presentations 6
• Progressive cognitive decline that may mimic dementia 2
• Mean time to symptom onset is approximately 23.75 days after trauma 5

Important Clinical Context

• No preceding injury identified in 31.6% of acute hematomas, 50% of subacute hematomas, and 61.9% of chronic hematomas—meaning many patients present without clear trauma history 5
• Symptoms similar to hepatic encephalopathy may occur, requiring differentiation; subdural hematomas are commonly accompanied by other neurological symptoms such as hemiplegia 2

Special Populations: Older Adults and Anticoagulated Patients

Elderly patients on anticoagulation or antiplatelet therapy have markedly higher risk of delayed acute subdural hematoma, with 70% deteriorating within the first 24 hours and requiring 24-hour observation with repeat CT imaging. 3

Risk Factors and Presentation Patterns

• Age >60 years increases risk of abnormal CT findings and clinical deterioration 3
• Anticoagulation therapy is present in 42-68% of cases requiring delayed surgery 7
• Antiplatelet agents (present in 5 of 8 patients requiring delayed surgery in one series) increase bleeding risk 7
• Falls are the most common mechanism of injury in elderly patients requiring delayed surgery 7
• Delayed hemorrhage occurs in 1.4-4.5% of anticoagulated patients even with initially negative CT 3

Atypical Presentations

• Subdural hematoma from spontaneous intracranial hypotension may present with postural headache (83% of cases), nausea/vomiting (28%), sensory changes (11%), auditory disturbance (11%), seizures (8%), disequilibrium (8%), altered mental status (8%), visual disturbance (3%), and plegia/paresis (3%) 2
• Contrast-enhanced MRI of brain and whole spine should be performed when subdural hematoma occurs without clear trauma history to evaluate for CSF leak 1

Critical Pitfalls in Recognition

• Clinical presentation alone is insufficient to reliably differentiate subdural hematoma from other stroke subtypes—brain imaging is mandatory 2
• Hematoma expansion occurs in 28-38% of patients initially scanned within 3 hours of onset, with two-thirds of growth occurring within the first hour 2, 1
• Elevated INR >3.0 is associated with significantly larger hematoma volumes and higher risk of expansion 8
• Hemosiderin deposition is rarely seen in chronic subdural hematomas on MRI, unlike chronic parenchymal hematomas, due to absence of blood-brain barrier allowing clearance of blood products 9