Cerebral Hemorrhage: Causes

Pathogenesis (disease development)

Primary intracerebral hemorrhage is caused by rupture (rupture) of vessels running in the brain parenchyma (brain substance, brain tissue) that have wall weakness. It bleeds into the brain parenchyma or into the cerebrospinal fluid space (here: cavity system in/around the brain).Long-standing hypertension (high blood pressure) promotes degeneration of the vessel walls – they lose elasticity. The small cerebral arterioles are particularly affected. They arise at right angles to the large arteries and are exposed to increased intravascular pressure (pressure in the vessel). There is also always the risk that further vessels may burst (“snowball effect”).Brain damage with neuronal dysfunction occurs in the affected brain area. The leaked blood represents a mass. In most cases, larger hemorrhages lead to an increase in intracranial pressure (ICP). In addition, peri-hemorrhagic (perifocal) edema often develops during the course, which also increases ICP. If the hemorrhage breaks into the ventricular system (cavity system in the brain), there may be disturbances in the circulation of cerebrospinal fluid (CSF). Eventually, occlusive hydrocephalus (hydrocephalus occlusus; pathologic/diseased dilatation of the fluid-filled fluid spaces (cerebral ventricles) of the brain) may develop.

Etiology (causes)

The location of the hemorrhage allows initial conclusions to be drawn regarding etiology (cause). For example, hypertensive mass hemorrhages occur more frequently deep in the brain, whereas intracerebral hematomas or hemorrhages from metastases, for example, occur more superficially (near the cortex (cerebral cortex)). Primary intracerebral hemorrhage (80-85% of cases).

Biographic causes

  • Hereditary microangiopathies – heterogeneous group of diseases in which pathological changes in the small cerebral vessels are found as a common characteristic.

Disease-related causes

  • Hypertension (high blood pressure) – leads to changes in small blood vessels over time.
  • Cerebral amyloid angiopathy (ZAA) – degenerative vasculopathy (vascular damage) resulting from deposits of beta-amyloid (peptides/certain protein molecules) in wall layers; beta-amyloid plaques are also considered a major trigger of dementia and Alzheimer’s disease; prevalence (disease incidence) is 30% in 60- to 69-year-olds and 50% in 70- to 89-year-olds

Secondary intracerebral hemorrhage (15-20% of cases).

Behavioral causes

  • Consumption of stimulants
    • Alcohol abuse (alcohol dependence)
  • Drug use
    • Amphetamines
    • Crystal meth
    • Cocaine
  • Overweight (BMI ≥ 25; obesity) – leads to increased bleeding volume.

Disease-related causes

  • Arteriitis (inflammation of one or more arteries) (rare).
  • Bleeding diathesis (increased bleeding tendency) or coagulation disorders – usually triggered by anticoagulation (anticoagulants) prescribed to prevent ischemic apoplexy (strokes caused by vascular occlusion) in existing atrial fibrillation or after the occurrence of deep vein thrombosis and pulmonary embolism (see below under “Medications”), but may also be disease-related: Hemophilia (hemophilia), hepatic insufficiency (dysfunction of the liver with partial or complete failure of its metabolic functions), leukemias (blood cancer), thrombocytopenia (lack of platelets); often large hematoma volume.
  • Eclampsia (“pregnancy cramp”) (rare).
  • Vascular anomalies such as angiomas (blood sponges), arteriovenous malformation (AVM/congenital malformation of blood vessels), durafistula (pathological/diseased short-circuit connection between arteries and veins at the level of the meninges), cerebral aneurysm, cerebral cavernous malformation (abnormality of the vascular system) – usually hemorrhage into the subarachnoid space (space between the arachnoid mater (soft meninges) and the middle meninges). middle meninges), rarely bleeding into the ventricular system (cavity system in the brain); often occurs in younger patients without hypertension.
  • Infective endocarditis (endocarditis of the heart).
  • Intracranial tumors or brain metastases (rare).
  • Moyamoya disease (from jap.moyamoya “mist”) (rare) – disease of cerebral vessels (especially the internal carotid artery and the middle cerebral artery) in which there is stenosis (narrowing) or obliteration (occlusion) of cerebral arteries; rare cause of juvenile apoplexy in children, adolescents, and young adults
  • Reversible cerebral vasoconstriction syndrome (RCVS) – due to contraction of the muscles of cerebral vessels comes to severe annihilation headache, possibly with neurological abnormalities.
  • Cerebral venous and sinus thrombosis (CVT) (rare) – occlusion of a cerebral sinus (from duraduplicatures emerging large venous blood vessels of the brain) by a thrombus (blood clot).
  • Cerebral vasculitis (inflammation of vessel walls in the brain).

Medication