Cerebrovascular
Stroke occurs when blood supply to part of the brain is interrupted; when it damages language centres, it can cause aphasia - difficulty producing or understanding language.
A stroke occurs when blood flow to part of the brain is interrupted, either by a blockage (ischaemic stroke, the most common type) or bleeding (haemorrhagic stroke), depriving brain tissue of oxygen. Because different brain regions handle different functions, the effects of a stroke depend heavily on exactly where it occurs. A stroke is a medical emergency - recognising symptoms quickly and seeking immediate treatment significantly improves outcomes, since "time is brain": brain tissue is lost rapidly the longer blood flow remains disrupted.
Stroke affecting the frontal lobe's Broca's area or the temporal lobe's Wernicke's area can cause aphasia - Broca's aphasia, marked by slow, effortful, fragmented speech with relatively preserved comprehension, or Wernicke's aphasia, marked by fluent but often meaningless speech and impaired comprehension. Stroke in the parietal lobe can cause spatial and sensory deficits, including hemispatial neglect, while stroke affecting the occipital lobe typically causes vision loss in part of the visual field.
Acute stroke treatment has advanced substantially, with clot-dissolving medication and mechanical clot-retrieval procedures now able to reverse or limit damage if given quickly enough after symptom onset. For aphasia and other lasting deficits, speech-language therapy remains the mainstay of recovery, and research into how the brain reorganises itself after injury (neuroplasticity) is informing newer rehabilitation approaches, including techniques that pair therapy with non-invasive brain stimulation.
This article is for general education and isn't a substitute for professional medical advice. If you suspect someone is having a stroke, seek emergency medical care immediately.
Explore the regions involved in stroke & aphasia in more depth:
