Definition and Overview
Cerebral hemorrhage or intracerebral hemorrhage (ICH) is a type of hemorrhagic stroke in which blood leaks within the brain parenchyma, forming a hematoma and compressing surrounding brain tissue. It is a diagnostic category distinct from subarachnoid hemorrhage and subdural hematoma.
It accounts for approximately 10-20% of all strokes, and although its incidence is lower than that of ischemic stroke, its 30-day mortality rate is significantly higher at approximately 40-50%. Approximately 75-80% of survivors are left with moderate to severe permanent functional impairment.
cause
High blood pressure accounts for approximately 50-70% of the causes of cerebral hemorrhage. Long-term high blood pressure damages small penetrating arteries located deep in the brain, forming lipohyalinosis and microaneurysms (Charcot-Bouchard aneurysms), and these blood vessels rupture. The most common areas are the basal ganglia (the most common is the putamen), thalamus, cerebellum, and pons.
Cerebral amyloid angiopathy (CAA) is a major cause of lobar hemorrhage in the elderly. Amyloid protein accumulates in the cerebral cortex and subcortical white matter, making blood vessels vulnerable. Taking anticoagulants (warfarin, direct oral anticoagulants), vascular malformations (arteriovenous malformations, AVM), ruptured cerebral aneurysms, tumor bleeding, and blood diseases (thrombocytopenia, coagulation abnormalities) are also causes.
pathophysiology
When a hematoma forms, primary damage occurs due to physical pressure. Afterwards, serum components leak around the hematoma, an inflammatory reaction progresses, and secondary damage occurs over several hours to several days in which the hemoglobin in the hematoma is broken down and toxic substances are released.
Hematoma expansion is the key to secondary damage. Hematoma expansion occurs in approximately 30 to 40% of cases within 24 hours after onset, especially within the first 3 to 6 hours, and this has a strong correlation with prognosis. Early and strong blood pressure control plays an important role in suppressing hematoma expansion.
clinical symptoms
Typical symptoms include sudden onset headache, nausea, vomiting, and loss of consciousness. Depending on the site of occurrence, local neurological disorders such as hemiplegia, sensory abnormalities, speech disorders, and eye movement abnormalities are accompanied.
Basal ganglia (putamen) hemorrhage: Hemiplegia, unilateral sensory loss, and headache are common. Thalamic hemorrhage: unilateral sensory loss is prominent and oculomotor abnormalities (eyes turn downward and adduct) appear. Cerebellar hemorrhage: Sudden vomiting, dizziness, and gait ataxia occur, and the main symptoms may be a headache in the back of the head without loss of consciousness. Brainstem hemorrhage: This has the poorest prognosis as it rapidly leads to loss of consciousness and causes quadriplegia and respiratory abnormalities.
diagnosis
Non-contrast brain CT is the gold standard for emergency diagnosis. Cerebral hemorrhage is immediately identified as a high-density shadow on CT. CT angiography (CTA) is used to evaluate vascular malformations, cerebral aneurysms, and contrast agent leakage (spot sign, predicting hematoma expansion). MRI (gradient echo, SWI sequence) is useful for etiological analysis and CAA evaluation.
treatment
Acute blood pressure control
Initial intensive blood pressure lowering (systolic blood pressure target of 140 mmHg) is recommended to inhibit hematoma expansion and to ensure safety. The ATACH-2 and INTERACT2 studies showed that controlling systolic blood pressure below 140 mmHg was safe and tended to increase the likelihood of neurological recovery.
Anticoagulation reversal
In case of cerebral hemorrhage while taking anticoagulants, immediate reversal of anticoagulation is essential. Warfarin reverses the 4-factor prothrombin complex concentrate (4-factor PCC). DOACs (direct oral anticoagulants) use drug-specific reversal agents (dabigatran → idarucizumab, Xa inhibitor → andexanet alfa).
surgery
Surgery is considered when cerebellar hemorrhage is more than 3 cm in diameter, is accompanied by intraventricular hematoma, and decreases consciousness. For cerebral lobe hemorrhages and superficial hematomas, craniotomy or minimally invasive endoscopic hematoma removal is performed. If intracranial pressure increases, extraventricular drainage (EVD) is performed.