More common * Stroke or brain anoxia. * Brain tumor * Brain trauma Less common * Autoimmune disease * Paraneoplastic syndrome * Micrometastasis * neurodegenerative disorders * Certain infections (e.g., Bartonella henselae) * Metabolic disease (e.g., hyperosmolar hyperglycemic state) Common causes The most common cause of<unk>  is stroke. A stroke is caused by hypoperfusion (lack of oxygen) to an area of the brain, which is commonly caused by thrombosis or embolism. Some form of aphasia occurs in 34 to 38% of stroke patients.<unk>  occurs in approximately 12% of new cases of aphasia caused by stroke. In most cases,<unk>  is caused by a stroke in Broca's area or the surrounding vicinity. Broca's area is in the lower part of the premotor cortex in the language dominant hemisphere and is responsible for planning motor speech movements. However, cases of<unk>  have been seen in patients with strokes in other areas of the brain. Patients with classic symptoms of<unk>  in general have more acute brain lesions, whereas patients with larger, widespread lesions exhibit a variety of symptoms that may be classified as global aphasia or left unclassified.<unk>  can also be caused by trauma to the brain, tumor, cerebral hemorrhage and by extradural abscess. Understanding lateralization of brain function is important for understanding which areas of the brain cause<unk>  when damaged. In the past, it has been believed that the area for language production differs between left and right-handed individuals. If this were true, damage to the homologous region of Broca's area in the right hemisphere should cause aphasia in a left-handed individual. More recent studies have shown that even left-handed individuals typically have language functions only in the left hemisphere. However, left-handed individuals are more likely to have a dominance of language in the right hemisphere. Uncommon causes Less common causes of<unk>  include primary autoimmune phenomenon and autoimmune phenomenon that are secondary to cancer (as a paraneoplastic syndrome) have been listed as the primary hypothesis for several cases of aphasia, especially when presenting with other psychiatric disturbances and focal neurological deficits. Many case reports exist describing paraneoplastic aphasia, and the reports that are specific tend to describe<unk> . Although most cases attempt to exclude micrometastasis, it is likely that some cases of paraneoplastic aphasia are actually extremely small metastasis to the vocal motor regions. Neurodegenerative disorders may present with aphasia. Alzheimer's disease may present with either fluent aphasia or<unk> . There are case reports of Creutzfeldt-Jakob disease presenting with<unk> .
Expressive aphasia
Global aphasia
Receptive aphasia
Anomic aphasia
Jargon aphasia
Progressive nonfluent aphasia
Hemispatial neglect
Apraxia of speech