The term
aphasia is used to refer to an acquired language disorder, usually resulting from damage to the left hemisphere of the brain, that affects language processing. Aphasia may be caused by a stroke, traumatic brain injury, or various neurodegenerative diseases. There are various types of aphasia, depending on the area of the brain affected. Below is a non-comprehensive list of some of the more common types of aphasia.
Wernicke's Aphasia Wernicke's aphasia is characterized by impaired language comprehension for both spoken and written language, caused by damage to Wernicke's Area. Patients with Wernicke's aphasia can still speak with normal fluency and prosody, and follow grammatical rules with normal sentence structure. However, they may exhibit difficulty with repetition tasks, naming items, and written word spelling. People with Wernicke's aphasia often exhibit other forms of aphasia. Phonemic paraphasia refers to making errors in the selection of phones, a vowel or consonant sound, including errors of addition, omission, or change in position. Semantic paraphasia is a common feature of Wernicke's aphasia that involves fluent speech that contains paraphasic errors resulting from the failure to select the proper words to convey one's ideas. This deficiency can be partially compensated for using paraphrases that rely on generic terms to stand in for the hard-to-find specific words.
Transcortical Sensory Aphasia Transcortical sensory aphasia (TSA) has a lot in common with Wernicke's aphasia, as the causation brain damage are in areas of the brain very close to each other. Patients with TSA are able to produce connected, flowing speech that often lacks meaning due to word errors and invented words.
Broca's Aphasia Broca's aphasia is an expressive language disorder that affects one's ability to speak and produce language, often accompanied by a loss of normal grammatical structure. Symptoms include having trouble forming sentences, difficulty repeating phrases, and leaving out linking words, conjunctions, and prepositions. In patient's with Broca's aphasia, language comprehension is intact and produced words are generally intelligible and contextually appropriate. This language disorder is caused by damage to Broca's area, the region in the left inferior frontal lobe, or it's connections to other areas of the brain. The most common cause of Broca's aphasia is ischemic stroke. Other possible causes include traumatic brain injuries, tumors, infections, and neurodegenerative conditions.
Transcortical Motor Aphasia Transcortical Motor Aphasia (TMA) is a type of non-fluent aphasia that's similar to Broca's aphasia, as it results form stroke or brain injury near Broca's area that can isolate Broca's area from other areas of the brain. People with TMA typically have good repetition skills, but struggle with spontaneous speech and rather producing speech with a lot of abrupt starts and stops. Other symptoms of TMA include difficulty with word-finding, sentence structure, intonation and rhythm, writing, and initiating speech.
Conduction Aphasia Conduction aphasia is a mild expressive language disorder characterized by the inability to repeat words or phrases, defective use of phonemes, and impaired naming ability. Patients with conduction aphasia struggle to may also have mild impairments with spoken language, such as paraphasias (word and sound substitutions) and difficulty finding the appropriate word. They can usually read, write, speak, and understand spoken messages with little difficulty.
Mixed Transcortical Aphasia Mixed Transcortical Aphasia (MTA) is a rare, but more severe form of global aphasia. This language disorder is characterized by characterized by non-fluent language that lacks prosody, echolalia (repetition of what is said to them), difficulty creating spontaneous language, impaired reading and writing, and difficulties with language comprehension. Patients with MTA typically respond only when prompted and verbal output may be limited to repetition of examiner prompts. Mixed Transcortical Aphasia has also been called isolation aphasia, as it is caused by damage to the brain that isolates Broca's area and Wernicke's area from the rest of the brain.
Primary Progressive Aphasia Primary progressive aphasia (PPA) is a relatively rare neurological syndrome caused by neurodegenerative diseases such as dementia, Alzheimer's, and frontotemporal lobar degradation. This means that symptoms will get worse over time. The symptoms of PPA vary depending on which areas of the brain have been affected, and can include non-fluent speech, language comprehension deficits, and the inability to read and write. There are three types of PPA. Semantic PPA involves a difficulty with naming familiar items and comprehending the meaning of individual words. Agrammatic / nonfluent PPA is characterized by a reduced amount of speech output and difficulty pronouncing words. Patients with agrammatic PPA often present with slower and halting speech, and issues with sentence structure and grammar. Logopenic PPA is a difficulty with repeating spoken language and finding words, such as recalling the names of objects and thinking of the right word in conversation. == Treatment ==