Global aphasia
Encyclopedia
Global aphasia is a type of aphasia
Aphasia
Aphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....

 that is commonly associated with a large lesion in the perisylvian area of the frontal, temporal and parietal lobes of the brain causing an almost total reduction of all aspects of spoken and written language. It involves a "left side blowout" which includes Broca's area
Broca's area
Broca's area is a region of the hominid brain with functions linked to speech production.The production of language has been linked to the Broca’s area since Pierre Paul Broca reported impairments in two patients. They had lost the ability to speak after injury to the posterior inferior frontal...

, Wernicke's area
Wernicke's area
Wernicke's area is one of the two parts of the cerebral cortex linked since the late nineteenth century to speech . It is involved in the understanding of written and spoken language...

 and the Arcuate fasciculus
Arcuate fasciculus
The arcuate fasciculus is the neural pathway connecting the posterior part of the temporoparietal junction with the frontal cortex in the brain and is now considered as part of the superior longitudinal fasciculus..-Neuroanatomy:...

. It can also be seen in the initial stages of large left middle cerebral artery
Middle cerebral artery
-External links:*...

 injuries that may progressively improve to become Broca's aphasia.

Global aphasia has been cited as among the most common type of aphasia in patients referred for speech rehabilitation therapy.

Presentation

The presentation of global aphasia are those of severe Broca's aphasia and Wernicke's aphasia combined. There is absence or severe impairment of both comprehension and expression of language. Persons with global aphasia are often mute
Muteness
Muteness or mutism is an inability to speak caused by a speech disorder. The term originates from the Latin word mutus, meaning "silent".-Causes:...

 or reduced to a few stereotyped words or sounds.

What is interesting to point out is that with patients of global aphasia other cognitive skills remain functioning - a phenomenon affirming that language faculty is indeed a separate domain.

Prognosis

Persons with a large injury to the left perisylvian areas of the brain, often initially show signs of global aphasia in the first 1–2 days due to brain swelling (cerebral edema
Cerebral edema
Cerebral edema or cerebral œdema is an excess accumulation of water in the intracellular or extracellular spaces of the brain.-Vasogenic:Due to a breakdown of tight endothelial junctions which make up the blood-brain barrier...

). With some recovery, impairment presentation may progess into Broca's (most commonly) or Wernicke's aphasia. Improvement may occur in one or both areas (expressive and receptive language) over time. However, studies show that spontaneous improvement, if it happens, occurs within six months, but complete recovery is rare.
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