Most intracerebral hemorrhages occur in the basal ganglia, cerebral lobes, cerebellum, or pons. Intracerebral hemorrhage may also occur in other parts of the brain stem or in the midbrain.
Etiology of Intracerebral Hemorrhage
Intracerebral hemorrhage usually results from rupture of an arteriosclerotic small artery that has been weakened, primarily by chronic arterial hypertension Hypertension Hypertension is sustained elevation of resting systolic blood pressure (≥ 130 mm Hg), diastolic blood pressure (≥ 80 mm Hg), or both. Hypertension with no known cause (primary; formerly, essential... read more . Such hemorrhages are usually large, single, and catastrophic. Other modifiable risk factors that contribute to arteriosclerotic hypertensive intracerebral hemorrhages include cigarette smoking, obesity Selected Stroke Syndromes A transient ischemic attack (TIA) is focal brain ischemia that causes sudden, transient neurologic deficits and is not accompanied by permanent brain infarction (eg, negative results on diffusion-weighted... read more , and a high-risk diet (eg, high in saturated fats, trans fats, and calories). Use of cocaine or, occasionally, other sympathomimetic drugs can cause transient severe hypertension leading to hemorrhage.
Less often, intracerebral hemorrhage results from congenital aneurysm Brain Aneurysms Brain aneurysms are focal dilations in the cerebral arteries. In the US, brain aneurysms occur in 3 to 5% of people. Brain aneurysms can occur at any age but are most common among people aged... read more , arteriovenous malformations Cerebral Arteriovenous Malformations (AVMs) Arteriovenous malformation (AVMs) are tangled, dilated blood vessels in which arteries flow directly into veins. AVMs occur most often at the junction of cerebral arteries, usually within the... read more , other vascular malformations, trauma Traumatic Brain Injury (TBI) Traumatic brain injury (TBI) is physical injury to brain tissue that temporarily or permanently impairs brain function. Diagnosis is suspected clinically and confirmed by imaging (primarily... read more , mycotic aneurysm, brain infarct (hemorrhagic infarction), primary or metastatic brain tumor, excessive anticoagulation, blood dyscrasia, intracranial arterial dissection, moyamoya disease, or a bleeding or vasculitic disorder.
Lobar intracerebral hemorrhages (hematomas in the cerebral lobes, outside the basal ganglia) usually result from angiopathy due to amyloid deposition in cerebral arteries (cerebral amyloid angiopathy), which affects primarily older people. Lobar hemorrhages may be multiple and recurrent.
Pathophysiology of Intracerebral Hemorrhage
Blood from an intracerebral hemorrhage accumulates as a mass that can dissect through and compress adjacent brain tissues, causing neuronal dysfunction. Large hematomas increase intracranial pressure. Pressure from supratentorial hematomas and the accompanying edema may cause transtentorial brain herniation Brain Herniation Brain herniation occurs when increased intracranial pressure causes the abnormal protrusion of brain tissue through openings in rigid intracranial barriers (eg, tentorial notch). Because the... read more , compressing the brain stem and often causing secondary hemorrhages in the midbrain and pons.
If the hemorrhage ruptures into the ventricular system (intraventricular hemorrhage), blood may cause acute hydrocephalus. Cerebellar hematomas can expand to block the 4th ventricle, also causing acute hydrocephalus, or they can dissect into the brain stem. Cerebellar hematomas that are > 3 cm in diameter may cause midline shift or herniation.
Herniation, midbrain or pontine hemorrhage, intraventricular hemorrhage, acute hydrocephalus, or dissection into the brain stem can impair consciousness and cause coma and death.
Symptoms and Signs of Intracerebral Hemorrhage
Symptoms of intracerebral hemorrhage typically begin with sudden headache, often during activity. However, headache may be mild or absent in older people. Loss of consciousness is common, often within seconds or a few minutes. Nausea, vomiting, delirium, and focal or generalized seizures are also common.
Neurologic deficits are usually sudden and progressive. Large hemorrhages, when located in the hemispheres, cause hemiparesis; when located in the posterior fossa, they cause cerebellar or brain stem deficits (eg, conjugate eye deviation or ophthalmoplegia, stertorous breathing, pinpoint pupils, coma).
Large hemorrhages are fatal within a few days in about half of patients. In survivors, consciousness returns and neurologic deficits gradually diminish to various degrees as the extravasated blood is resorbed. Some patients have surprisingly few neurologic deficits because hemorrhage is less destructive to brain tissue than infarction.
Small hemorrhages may cause focal deficits without impairment of consciousness and with minimal or no headache and nausea. Small hemorrhages may mimic ischemic stroke Ischemic Stroke Ischemic stroke is sudden neurologic deficits that result from focal cerebral ischemia associated with permanent brain infarction (eg, positive results on diffusion-weighted MRI). Common causes... read more .
Diagnosis of Intracerebral Hemorrhage
Diagnosis of intracerebral hemorrhage is suggested by sudden onset of headache, focal neurologic deficits, and impaired consciousness, particularly in patients with risk factors.
Intracerebral hemorrhage must be distinguished from
Other causes of acute neurologic deficits (eg, seizure Seizure Disorders A seizure is an abnormal, unregulated electrical discharge that occurs within the brain’s cortical gray matter and transiently interrupts normal brain function. A seizure typically causes altered... read more , hypoglycemia Hypoglycemia Hypoglycemia unrelated to exogenous insulin therapy is an uncommon clinical syndrome characterized by low plasma glucose level, symptomatic sympathetic nervous system stimulation, and central... read more )
Blood glucose level should be measured at the bedside immediately.
Immediate CT or MRI is necessary. Neuroimaging is usually diagnostic. If neuroimaging shows no hemorrhage but subarachnoid hemorrhage is suspected clinically, lumbar puncture Lumbar Puncture (Spinal Tap) Lumbar puncture is used to do the following: Evaluate intracranial pressure and cerebrospinal fluid (CSF) composition (see table Cerebrospinal Fluid Abnormalities in Various Disorders) Therapeutically... read more is necessary. CT angiography, done within hours of bleeding onset, may show areas where contrast extravasates into the clot (spot sign); this finding indicates that bleeding is continuing and suggests that the hematoma will expand and the outcome will be poor.
Treatment of Intracerebral Hemorrhage
Control of modifiable risk factors
Sometimes surgical evacuation (eg, for many cerebellar hematomas > 3 cm)
Treatment of intracerebral hemorrhage includes supportive measures and control of modifiable risk factors.
Anticoagulants and antiplatelet drugs are contraindicated. If patients have used anticoagulants, the effects are reversed when possible by giving fresh frozen plasma, prothrombin complex concentrate, vitamin K, or platelet transfusions as indicated. Hemodialysis can remove about 60% of dabigatran.
As recommended by the American Heart Association and American Stroke Association 2015 guidelines, hypertension can be safely lowered to systolic blood pressure (BP) 140 mm Hg if systolic BP is between 150 mm Hg and 220 mm Hg and if acute antihypertensive treatment is not contraindicated (1 Treatment reference Intracerebral hemorrhage is focal bleeding from a blood vessel in the brain parenchyma. The cause is usually hypertension. Typical symptoms include focal neurologic deficits, often with abrupt... read more ). If systolic BP is > 220 mm Hg, hypertension can be treated aggressively with a continuous IV infusion; in such cases, systolic BP must be monitored frequently. Nicardipine 2.5 mg/hour IV is given initially; dose is increased by 2.5 mg/hour every 5 minutes to a maximum of 15 mg/hour as needed to decrease systolic BP by 10 to 15%.
Cerebellar hemisphere hematomas that are > 3 cm in diameter may cause midline shift or herniation, so surgical evacuation is often lifesaving. Early evacuation of large lobar cerebral hematomas may also be lifesaving, but rebleeding occurs frequently, sometimes increasing neurologic deficits. Early evacuation of deep cerebral hematomas is seldom indicated because surgical mortality is high and neurologic deficits are usually severe.
Antiseizure drugs are not typically used prophylactically; they are used only if patients have had a seizure.
1. Hemphill JC, Greenberg SM, Anderson CS, et al: Guidelines for the management of spontaneous intracerebral hemorrhage: A guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke 46:2032–2060, 2015. https://doi.org/10.1161/STR.0000000000000069.
With intracerebral hemorrhage, sudden, severe symptoms (eg, sudden headache, loss of consciousness, vomiting) are common, but headache may be absent (particularly in older people), and small hemorrhages may mimic ischemic stroke.
Do CT or MRI and a bedside glucose test immediately.
Essential supportive care may include reversing anticoagulation and decreasing BP if systolic BP is > 150 mm Hg; if systolic BP is > 220 mm Hg, consider aggressively reducing BP by continuously infusing nicardipine IV.
Consider surgical evacuation for large lobar cerebral hematomas and hematomas > 3 cm in a cerebellar hemisphere.