Subdural Hemorrhage: Symptoms, Causes, and Treatment

Overview

The brain is protected by three layers of membranes called meninges: the dura mater (outermost), arachnoid mater (middle), and pia mater (innermost). A subdural hemorrhage occurs when blood vessels, typically bridging veins that connect the brain surface to the dural sinuses, tear and bleed into the space between the dura and arachnoid layers.

Unlike epidural hemorrhages, which occur between the skull and dura mater, subdural hemorrhages develop more slowly and can be more difficult to detect initially. The accumulated blood forms a hematoma that gradually increases pressure on the brain, leading to potentially severe neurological complications if left untreated.

Subdural hemorrhages affect approximately 1-2 people per 100,000 annually, with higher rates in elderly populations and those on anticoagulant medications. The condition has a significant mortality rate, particularly in acute cases, making early recognition and treatment crucial for optimal outcomes.

The prognosis varies significantly depending on the size of the hemorrhage, the patient's age and overall health, the time between onset and treatment, and the presence of other brain injuries. With prompt medical intervention, many patients can achieve good recovery, though some may experience lasting neurological effects.

Types of Subdural Hemorrhage

Acute Subdural Hemorrhage

Timeframe: Symptoms develop within 24-72 hours
Cause: Usually high-impact trauma with brain injury
Presentation: Rapid deterioration, altered consciousness
Prognosis: More serious, higher mortality rate
Treatment: Often requires emergency surgery

Subacute Subdural Hemorrhage

Timeframe: Symptoms develop over 3-20 days
Presentation: Gradual onset of neurological symptoms
Diagnosis: May be more challenging due to subtle symptoms
Treatment: Management depends on size and symptoms

Chronic Subdural Hemorrhage

Timeframe: Symptoms develop over weeks to months
Population: More common in elderly patients
Cause: Often from minor trauma or spontaneous bleeding
Symptoms: Gradual cognitive decline, headaches
Prognosis: Generally better than acute forms

Based on Location

Unilateral: Affecting one side of the brain
Bilateral: Affecting both sides, more common in chronic cases
Tentorial: Located near the tentorium cerebelli
Posterior fossa: Located in the back of the skull

Symptoms

The symptoms of subdural hemorrhage can vary significantly depending on the type (acute, subacute, or chronic), size of the hemorrhage, and individual patient factors. Some symptoms may develop rapidly, while others emerge gradually over time.

Early Warning Signs

Headache - often severe and persistent
Dizziness and balance problems
Confusion and disorientation
Memory problems and difficulty concentrating
Nausea and vomiting
Changes in personality or behavior

Progressive Neurological Symptoms

Weakness on one side of the body (hemiparesis)
Speech difficulties (aphasia or dysarthria)
Vision problems or double vision
Coordination problems and unsteady gait
Numbness or tingling in arms or legs
Difficulty with fine motor tasks

Behavioral and Cognitive Changes

Depressive or psychotic symptoms
Agitation and restlessness
Inappropriate social behavior
Loss of inhibition
Difficulty with decision-making
Changes in sleep patterns

Emergency Symptoms

Severe, sudden headache
Loss of consciousness or coma
Seizures
Sudden weakness or paralysis
Difficulty breathing
Pupil changes (unequal or non-reactive pupils)

Infant and Pediatric Symptoms

Irritable infant behavior
Bulging fontanelle (soft spot on head)
Poor feeding and failure to thrive
Unusual sleepiness or lethargy
High-pitched crying
Developmental delays

Chronic Subdural Hemorrhage Symptoms

Gradual cognitive decline resembling dementia
Mild, persistent headaches
Facial pain or numbness
Urinary incontinence
Walking difficulties (gait disturbance)
Falls and balance problems

Causes

Subdural hemorrhages result from damage to bridging veins that connect the brain surface to the venous sinuses in the dura mater. These delicate vessels can tear due to various factors, leading to bleeding into the subdural space.

Traumatic Causes

High-Impact Trauma

Motor vehicle accidents: Rapid deceleration injuries
Falls from height: Particularly in elderly individuals
Sports injuries: Contact sports, cycling, skiing
Physical violence: Assault, domestic violence
Industrial accidents: Workplace head injuries

Low-Impact Trauma

Minor falls, especially in elderly or those on blood thinners
Sudden head movements or whiplash
Minor bumps or knocks to the head
Medical procedures involving head manipulation

Non-Traumatic Causes

Vascular Abnormalities

Cerebral aneurysm rupture: Leading to subarachnoid and subdural bleeding
Arteriovenous malformations (AVMs): Abnormal blood vessel connections
Cerebral vasculitis: Inflammation of brain blood vessels
Moyamoya disease: Progressive narrowing of brain arteries

Medical Conditions

Coagulopathy: Blood clotting disorders
Thrombocytopenia: Low platelet count
Liver disease: Affecting clotting factor production
Kidney disease: Leading to platelet dysfunction

Age-Related Factors

Brain atrophy: Creates more space for bleeding
Fragile blood vessels: Increased susceptibility to tearing
Decreased brain volume: Allows larger hematomas to develop
Multiple comorbidities: Increasing overall risk

Iatrogenic Causes

Neurosurgical procedures
Lumbar puncture complications
Ventricular shunt complications
Brain biopsy procedures

Risk Factors

Several factors can significantly increase the risk of developing a subdural hemorrhage. Understanding these risk factors helps in prevention and early recognition of the condition.

Demographic Risk Factors

Advanced age: Risk increases significantly after age 65
Male gender: Higher risk in men, especially for traumatic causes
Very young age: Infants at risk due to birth trauma or abuse
Elderly women: Higher risk for chronic subdural hemorrhage

Medical Risk Factors

Anticoagulant and Antiplatelet Medications

Warfarin: Significantly increases bleeding risk
Direct oral anticoagulants (DOACs): Rivaroxaban, apixaban, dabigatran
Antiplatelet agents: Aspirin, clopidogrel, ticagrelor
Heparin: Both unfractionated and low molecular weight

Underlying Medical Conditions

Atrial fibrillation: Often requiring anticoagulation
Liver disease: Impaired clotting factor production
Chronic kidney disease: Platelet dysfunction
Cancer: Especially with brain metastases
Bleeding disorders: Hemophilia, von Willebrand disease

Lifestyle and Environmental Risk Factors

Alcohol abuse: Increases fall risk and affects clotting
Drug abuse: Particularly cocaine and methamphetamines
High-risk activities: Contact sports, extreme sports
Occupational hazards: Construction, military service

Anatomical Risk Factors

Brain atrophy: Age-related brain volume loss
Hydrocephalus: Increased intracranial pressure
Previous brain surgery: Altered anatomy and adhesions
Arachnoid cysts: May increase vulnerability

Social Risk Factors

History of domestic violence
Elder abuse or neglect
Child abuse (shaken baby syndrome)
Lack of appropriate safety measures

Diagnosis

Diagnosing subdural hemorrhage requires a combination of clinical assessment, neurological examination, and advanced imaging studies. Early and accurate diagnosis is crucial for determining the appropriate treatment approach and preventing complications.

Clinical Assessment

Medical History

Trauma history: Recent head injury, falls, accidents
Medication review: Anticoagulants, antiplatelets
Symptom timeline: Onset, progression, severity
Past medical history: Previous neurological conditions
Social history: Alcohol use, living situation

Physical and Neurological Examination

Glasgow Coma Scale: Assessment of consciousness level
Neurological assessment: Motor, sensory, cognitive function
Pupillary examination: Size, reactivity, asymmetry
Signs of increased ICP: Papilledema, Cushing's triad
External injury assessment: Scalp wounds, bruising

Imaging Studies

Computed Tomography (CT) Scan

First-line imaging: Rapidly available, excellent for acute bleeding
Acute SDH appearance: Hyperdense (bright) crescent-shaped lesion
Chronic SDH appearance: Hypodense (dark) or mixed density
Midline shift: Indicates mass effect and increased pressure
Additional findings: Brain edema, herniation signs

Magnetic Resonance Imaging (MRI)

Superior soft tissue contrast: Better visualization of brain tissue
Age determination: Can help date the hemorrhage
Small hemorrhages: May detect lesions missed on CT
Vascular assessment: MRA can identify underlying abnormalities
Contraindications: Pacemakers, some metallic implants

Laboratory Tests

Complete blood count: Platelet count, hemoglobin levels
Coagulation studies: PT/INR, aPTT, platelet function
Liver function tests: Assessing clotting factor production
Kidney function: Creatinine, BUN
Toxicology screen: If substance abuse suspected

Advanced Diagnostic Procedures

Cerebral angiography: When vascular malformation suspected
Intracranial pressure monitoring: In severe cases
Electroencephalography (EEG): If seizures suspected
Neuropsychological testing: For chronic cases

Differential Diagnosis

Epidural hemorrhage
Intracerebral hemorrhage
Subarachnoid hemorrhage
Brain tumor
Stroke (ischemic)
Dementia
Meningitis or encephalitis

Treatment Options

Treatment of subdural hemorrhage depends on several factors including the size of the hematoma, the patient's neurological status, age, comorbidities, and the acuity of presentation. Treatment approaches range from conservative management to emergency surgical intervention.

Emergency Management

Initial Stabilization

Airway management: Intubation if Glasgow Coma Scale ≤8
Blood pressure control: Maintain cerebral perfusion pressure
Intracranial pressure management: Elevate head of bed 30 degrees
Reversal of coagulopathy: Vitamin K, fresh frozen plasma, or specific reversal agents
Seizure prophylaxis: Anti-epileptic drugs if indicated

Medical Management of Increased ICP

Osmotic therapy: Mannitol or hypertonic saline
Hyperventilation: Temporary measure to reduce CO2
Sedation: Reduce cerebral metabolic demand
Temperature control: Prevent hyperthermia

Surgical Treatment

Craniotomy

Indications: Large acute SDH, significant mass effect
Procedure: Large bone flap removal for hematoma evacuation
Advantages: Complete evacuation, good visualization
Complications: Higher morbidity, longer recovery

Burr Hole Drainage

Indications: Chronic SDH, liquid hematoma
Procedure: Small holes drilled in skull for drainage
Advantages: Less invasive, local anesthesia possible
Success rate: 70-90% for appropriate cases

Subdural-Peritoneal Shunt

Indications: Recurrent chronic SDH
Procedure: Catheter placement for continuous drainage
Considerations: Risk of shunt malfunction or infection

Conservative Management

Indications for Conservative Treatment

Small, asymptomatic hematomas
Stable neurological status
High surgical risk patients
Chronic SDH with minimal symptoms

Conservative Management Approach

Serial neurological assessments: Regular monitoring
Repeat imaging: CT scans at regular intervals
Symptomatic treatment: Pain management, anti-emetics
Coagulopathy reversal: Normalize clotting parameters

Post-Treatment Care

Immediate Post-Operative Care

Intensive care monitoring
Neurological assessments every 1-2 hours
Blood pressure management
Fluid and electrolyte balance
Prevention of complications

Rehabilitation

Physical therapy: Mobility and strength recovery
Occupational therapy: Activities of daily living
Speech therapy: Communication and swallowing
Neuropsychological rehabilitation: Cognitive recovery

Complications and Management

Rebleeding: Occurs in 5-10% of cases
Infection: Post-operative wound or intracranial
Seizures: Early or late onset
Hydrocephalus: May require shunt placement
Cognitive impairment: Long-term neurological deficits

Prevention

While not all subdural hemorrhages can be prevented, many cases can be avoided through appropriate safety measures, medical management, and lifestyle modifications, particularly in high-risk populations.

Injury Prevention

Fall Prevention in Elderly

Home safety modifications: Remove tripping hazards, improve lighting
Assistive devices: Grab bars, non-slip mats, walkers
Medication review: Assess fall-risk medications
Vision and hearing checks: Regular screening and correction
Exercise programs: Balance and strength training

Sports and Activity Safety

Protective equipment: Proper helmets for cycling, skiing, sports
Safety rules compliance: Following sport-specific guidelines
Proper training: Adequate preparation for activities
Risk assessment: Avoiding unnecessarily high-risk activities

Vehicle Safety

Seat belt use at all times
Proper child car seat installation and use
Avoiding driving under influence
Motorcycle helmet laws compliance

Medical Management

Anticoagulation Management

Risk-benefit assessment: Careful evaluation before prescribing
Regular monitoring: INR checks for warfarin users
Patient education: Signs of bleeding, when to seek help
Drug interactions: Avoiding medications that increase bleeding risk

Chronic Disease Management

Optimal blood pressure control
Diabetes management
Treatment of underlying bleeding disorders
Regular medical follow-up

High-Risk Population Strategies

Elderly Patients

Comprehensive geriatric assessment
Fall risk stratification
Caregiver education and support
Regular health monitoring

Patients on Anticoagulants

Enhanced fall prevention measures
Regular coagulation monitoring
Emergency action plans
Medical alert identification

Child Protection

Abuse prevention: Education and reporting systems
Safe environments: Childproofing homes and play areas
Supervision: Appropriate adult oversight
Education: Teaching children about safety

When to See a Doctor

Call 911 immediately for:

Loss of consciousness after head injury
Severe, worsening headache
Repeated vomiting
Confusion or disorientation
Seizures
Weakness or numbness on one side
Difficulty speaking or understanding
Vision changes or double vision
Unequal pupil sizes
Difficulty breathing

Seek immediate medical evaluation for:

Any head injury in someone on blood thinners
Head injury in elderly patients, even if minor
Persistent headache after head trauma
Personality changes or unusual behavior
Memory problems after head injury
Balance problems or dizziness

Contact healthcare provider for:

Gradual cognitive decline in elderly
New onset facial pain or numbness
Changes in walking or coordination
Sleep pattern changes
Depressive or psychotic symptoms in elderly
Concerns about fall risk in elderly family members

Special Situations:

Infants: Any concerning behavior after potential head trauma
Anticoagulated patients: Even minor head injuries warrant evaluation
Recurrence: Return of symptoms after treatment

Related Conditions

Frequently Asked Questions

What is the difference between acute and chronic subdural hemorrhage?

Acute subdural hemorrhage develops rapidly (within 24-72 hours) after severe head trauma and typically requires emergency surgery. Chronic subdural hemorrhage develops slowly over weeks to months, often from minor trauma in elderly patients, and may be managed conservatively or with minimally invasive procedures.

Can subdural hemorrhage occur without head trauma?

Yes, subdural hemorrhage can occur spontaneously, especially in patients taking blood thinners, those with bleeding disorders, or individuals with vascular abnormalities. Elderly patients may develop chronic subdural hemorrhage from very minor trauma that they don't even remember.

What is the recovery time for subdural hemorrhage?

Recovery varies widely depending on the severity, patient age, and treatment approach. Small, conservatively managed hemorrhages may resolve in weeks to months. Surgical cases may require several months of rehabilitation, and some patients may have permanent neurological deficits.

Is subdural hemorrhage always visible on CT scan?

While CT scans are excellent for detecting most subdural hemorrhages, very small or isodense (same density as brain) chronic hemorrhages might be missed. MRI is more sensitive for detecting subtle bleeding and can help determine the age of the hemorrhage.

Can subdural hemorrhage recur after treatment?

Yes, recurrence is possible, especially with chronic subdural hemorrhage. Rebleeding occurs in about 5-10% of cases. Risk factors for recurrence include advanced age, brain atrophy, anticoagulant use, and incomplete initial drainage.

References

Bullock MR, Chesnut R, Ghajar J, et al. Surgical management of acute subdural hematomas. Neurosurgery. 2006;58(3 Suppl):S16-24.
Kolias AG, Chari A, Santarius T, Hutchinson PJ. Chronic subdural haematoma: modern management and emerging therapies. Nat Rev Neurol. 2014;10(10):570-8.
Santarius T, Kirkpatrick PJ, Ganesan D, et al. Use of drains versus no drains after burr-hole evacuation of chronic subdural haematoma: a randomised controlled trial. Lancet. 2009;374(9695):1067-73.
Carney N, Totten AM, O'Reilly C, et al. Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition. Neurosurgery. 2017;80(1):6-15.
Adhiyaman V, Asghar M, Ganeshram KN, Bhowmick BK. Chronic subdural haematoma in the elderly. Postgrad Med J. 2002;78(916):71-5.