Brain haemorrhage

Brain haemorrhage is a serious neurological condition characterized by bleeding within the brain tissue or surrounding spaces. It is a leading cause of morbidity and mortality worldwide. Rapid diagnosis and understanding of the underlying anatomy and physiology are crucial for effective management and improved outcomes.

Anatomy and Physiology of the Brain Relevant to Haemorrhage

Vascular Anatomy

The brain’s vascular system is complex and highly specialized, making it susceptible to haemorrhage:

• Arterial system: Includes the Circle of Willis and major cerebral arteries supplying oxygenated blood to the brain.
• Venous system: Composed of cerebral veins and dural sinuses responsible for venous drainage.
• Microvascular networks: Small arterioles and capillaries that maintain tissue perfusion and are potential sites of rupture.

Brain Parenchyma and Compartments

The structural organization of the brain influences the clinical presentation and complications of haemorrhage:

• Cortical and subcortical structures: Including gray and white matter regions vulnerable to bleeding.
• Ventricular system: Lateral, third, and fourth ventricles that can be affected by intraventricular hemorrhage.
• Subarachnoid space and meninges: Spaces where bleeding can cause subarachnoid or subdural haemorrhage.

Classification of Brain Haemorrhage

Intracerebral Haemorrhage (ICH)

Bleeding directly into the brain parenchyma is classified based on location:

• Lobar haemorrhage affecting the cerebral lobes
• Deep brain haemorrhage involving basal ganglia or thalamus
• Brainstem haemorrhage affecting midbrain, pons, or medulla
• Cerebellar haemorrhage within the cerebellum

Subarachnoid Haemorrhage (SAH)

Bleeding into the subarachnoid space can be:

• Aneurysmal SAH resulting from ruptured cerebral aneurysms
• Non-aneurysmal or perimesencephalic SAH with idiopathic or minor vessel origin

Subdural Haemorrhage

Occurs between the dura and arachnoid mater:

• Acute subdural haemorrhage, usually traumatic
• Chronic subdural haemorrhage developing over weeks to months

Epidural Haemorrhage

Typically results from trauma causing arterial bleeding between the dura and skull:

• Traumatic epidural haemorrhage often associated with skull fractures

Etiology

Hypertensive Causes

Chronic hypertension is a major risk factor for spontaneous intracerebral haemorrhage. High blood pressure weakens small arteries and arterioles, predisposing them to rupture.

Vascular Abnormalities

Structural abnormalities in cerebral vessels can lead to haemorrhage:

• Cerebral aneurysms prone to rupture and cause subarachnoid haemorrhage
• Arteriovenous malformations (AVMs) creating high-flow shunts that may bleed
• Cavernous malformations which are low-flow vascular lesions susceptible to bleeding

Trauma

Head injuries are common causes of intracranial bleeding:

• Falls, motor vehicle accidents, or direct impacts can cause subdural, epidural, or intracerebral haemorrhage

Coagulopathy and Medications

Disorders affecting clotting can precipitate brain haemorrhage:

• Use of anticoagulants or antiplatelet medications
• Inherited or acquired bleeding disorders, such as hemophilia or thrombocytopenia

Other Causes

Additional etiologies include:

• Neoplasms causing spontaneous bleeding within tumors
• Drug-induced or toxic causes
• Infections or vasculitis affecting cerebral vessels

Pathophysiology

Brain haemorrhage involves complex mechanisms that lead to neurological damage and systemic complications:

• Vessel rupture and hematoma formation: Breach of vascular integrity allows blood to accumulate within brain tissue or surrounding spaces.
• Mass effect and increased intracranial pressure: Accumulated blood compresses adjacent brain structures, potentially causing herniation.
• Secondary injury: Blood breakdown products trigger inflammation, edema, oxidative stress, and neuronal death.
• Disruption of cerebral perfusion: Local ischemia occurs around the hemorrhage, exacerbating neurological deficits.

Clinical Presentation

Symptoms

The symptoms of brain haemorrhage depend on the location, size, and rate of bleeding. Common presentations include:

• Sudden, severe headache often described as the worst headache of life, particularly in subarachnoid haemorrhage
• Neurological deficits such as hemiplegia, aphasia, or visual disturbances
• Altered level of consciousness ranging from confusion to coma
• Seizures, especially in cortical haemorrhages
• Nausea and vomiting due to increased intracranial pressure

Signs

Physical examination may reveal objective findings that correlate with the location and severity of the haemorrhage:

• Focal neurological deficits, including weakness, sensory loss, or cranial nerve abnormalities
• Signs of raised intracranial pressure such as papilledema and hypertension with bradycardia
• Meningeal irritation signs, including neck stiffness and photophobia, particularly in subarachnoid haemorrhage
• Altered mental status ranging from drowsiness to coma

Diagnostic Evaluation

History and Physical Examination

Accurate history taking and thorough neurological examination are crucial for early diagnosis:

• Time of onset and progression of symptoms
• Risk factors including hypertension, trauma, anticoagulation, or prior vascular disease
• Associated systemic symptoms such as fever, vomiting, or seizures

Laboratory Tests

Laboratory investigations help identify contributing factors and guide management:

• Complete blood count to detect anemia or infection
• Coagulation profile including INR, PT, and aPTT for patients on anticoagulants or with bleeding disorders
• Renal and liver function tests to assess systemic contributions

Imaging Studies

Imaging is essential for confirming the presence, type, and extent of haemorrhage:

• Non-contrast CT scan of the brain to quickly detect acute bleeding
• MRI brain with susceptibility-weighted imaging for small or chronic haemorrhages
• CT or MR angiography to identify vascular lesions such as aneurysms or AVMs
• Digital subtraction angiography for definitive vascular assessment when intervention is considered

Special Tests

Additional diagnostic procedures may be utilized in selected cases:

• Lumbar puncture in cases of suspected subarachnoid haemorrhage when imaging is inconclusive
• Electrocardiogram and cardiac enzymes if systemic or cardiac involvement is suspected

Differential Diagnosis

Brain haemorrhage can mimic other neurological conditions, so careful evaluation is necessary to distinguish it from similar presentations:

• Ischemic stroke with hemorrhagic transformation
• Brain tumors presenting with sudden neurological deficits or hemorrhage
• Migrainous headaches with focal neurological symptoms
• Metabolic disturbances such as hypoglycemia or electrolyte imbalances
• Infections like meningitis or encephalitis causing acute neurological changes

Management

Initial Stabilization

Immediate care focuses on stabilizing vital functions and preventing further neurological damage:

• Airway protection and respiratory support
• Circulatory stabilization including blood pressure management
• Monitoring and management of intracranial pressure using medical or surgical interventions

Medical Management

Medical therapy aims to control contributing factors and prevent secondary injury:

• Reversal of coagulopathy using vitamin K, fresh frozen plasma, or specific antidotes
• Seizure prophylaxis with antiepileptic medications
• Pain management and supportive care, including fluid and electrolyte balance

Surgical Intervention

Surgery may be required depending on the type, size, and location of the haemorrhage:

• Craniotomy with hematoma evacuation to relieve mass effect
• Endovascular procedures for aneurysm clipping or coiling
• Decompressive craniectomy in cases of severe brain swelling

Rehabilitation

Post-acute care focuses on functional recovery and minimizing long-term disability:

• Physical therapy for motor function and balance
• Occupational therapy to restore daily living activities
• Speech and cognitive therapy for patients with language or cognitive deficits

Complications

Brain haemorrhage can lead to a range of acute and long-term complications depending on the size, location, and rapidity of bleeding:

• Rebleeding or expansion of the hematoma causing worsening neurological deficits
• Cerebral edema and increased intracranial pressure leading to herniation
• Hydrocephalus due to obstruction of cerebrospinal fluid pathways
• Seizures and post-hemorrhagic epilepsy
• Infections, especially post-surgical or post-traumatic
• Long-term cognitive, motor, or speech deficits resulting from brain tissue damage

Prognosis

The prognosis of brain haemorrhage varies widely based on etiology, location, size, patient age, and comorbidities. Key considerations include:

• Mortality rates are higher for large or brainstem haemorrhages compared to small, superficial bleeds
• Early medical and surgical intervention improves survival and functional outcomes
• Patients with underlying hypertension or coagulopathy may have increased risk of recurrence
• Long-term neurological deficits are common, necessitating rehabilitation and supportive care

Prevention

Preventing brain haemorrhage involves addressing modifiable risk factors and adopting strategies to reduce the likelihood of vascular injury:

• Effective blood pressure control through lifestyle modification and antihypertensive therapy
• Management of anticoagulant and antiplatelet medications with careful monitoring
• Screening and treatment of cerebral aneurysms or arteriovenous malformations in high-risk individuals
• Trauma prevention measures, including the use of seat belts, helmets, and fall-prevention strategies
• Healthy lifestyle choices such as regular exercise, balanced diet, and avoidance of smoking or excessive alcohol

References

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