Automatic dating of documents and temporal text classification
Some of these can include brain tumors, traumatic brain injury, and progressive neurological disorders.
A very small number of people can experience aphasia after damage to the right hemisphere only.
It has been suggested that these individuals may have had an unusual brain organization prior to their illness or injury, with perhaps greater overall reliance on the right hemisphere for language skills than in the general population.
PPA usually initiates with sudden word-finding difficulties in an individual and progresses to a reduced ability to formulate grammatically correct sentences (syntax) and impaired comprehension.
The etiology of PPA is not due to a stroke, traumatic brain injury (TBI), or infectious disease; it is still uncertain what initiates the onset of PPA in those affected by it.
There is a huge variation among patients within the same broad grouping, and aphasias can be highly selective.
For instance, patients with naming deficits (anomic aphasia) might show an inability only for naming buildings, or people, or colors.
Primary progressive aphasia (PPA), while its name can be misleading, is actually a form of dementia that has some symptoms closely related to several forms of aphasia.
It is characterized by a gradual loss in language functioning while other cognitive domains are mostly preserved, such as memory and personality.
A common approach is to distinguish between the fluent aphasias (where speech remains fluent, but content may be lacking, and the person may have difficulties understanding others), and the nonfluent aphasias (where speech is very halting and effortful, and may consist of just one or two words at a time).
However, no such broad-based grouping has proven fully adequate.
Signs and symptoms may or may not be present in individuals with aphasia and may vary in severity and level of disruption to communication.