Aphasia is an acquired disorder of language due to brain damage. It may occur secondary to brain injury or degeneration and involves the left cerebral hemisphere to a greater extent than the right.
Essential update: Face naming and facial recognition in primary progressive aphasia
According to a study of 30 patients with primary progressive aphasia (PPA) and 27 cognitively healthy controls, face naming deficits reflect damage in the left hemisphere of the brain, while face recognition problems signal impairment in both the left and the right side of the brain. Such distinctions can be clinically relevant, as locating the specific impairment’s point of origin is an important first step in treatment.
Researchers used the Northwestern University Famous Faces (NUFFACE) Test to examine the anatomical correlates of naming vs. recognizing faces. On the NUFFACE Test, controls had average naming accuracy of 93.4% and recognition of 96.9%. Patients with PPA scored significantly worse than controls on both the naming (46.4%) and recognition (78.5%) parts of the measure.
The researchers also compared cortical thinning in the PPA group and 35 healthy volunteers. In all patients with PPA, worse naming performance was associated with greater atrophy in the left temporal cortex. In contrast, the NUFFACE Test recognition performance was positively correlated with bilateral atrophy in the anterior temporal lobe.
Signs and symptoms
Aphasia develops abruptly in patients with a stroke or head injury. Patients with neurodegenerative diseases or mass lesions may develop aphasia insidiously.
People with aphasia may exhibit the following symptoms:
- Difficulty using words and sentences (expressive aphasia)
- Difficulty understanding others (receptive aphasia)
- Difficulty with both using words and understanding (global aphasia)
Patients may also experience problems with spoken and written language. Typically, reading and writing are more impaired than talking or understanding.
Diagnosis
Careful assessment of language function with an evaluation of neighborhood signs is important in the diagnosis of the localization and cause of aphasia. These signs include:
- difficulties with vision, especially hemianopia
- deficits of motor or sensory function
- neurobehavioral deficits such as alexia, agraphia, acalculia, or apraxia
Bedside examination
Components of bedside language examination include assessments of spontaneous speech, naming, repetition, comprehension, reading, and writing. Although bedside examination can usually reveal the type of aphasia, formal cognitive testing by a neuropsychologist or speech/language therapist may be important to determine fine levels of dysfunction, to plan therapy, and to assess the patient's potential for recovery.
Imaging tests
Because aphasia is most often caused by stroke, neuroimaging is required to localize and diagnose the cause of aphasia. CT scanning and MRI are the mainstays of neuroimaging.
Management
The treatment of a patient with aphasia depends on the cause of the aphasia syndrome. Acute stroke treatment for the aphasic patient, such as intravenous tPA, intra-arterial interventional treatments, carotid endarterectomy and stenting, or even blood pressure manipulation may help to alleviate the deficit. Surgery for a subdural hematoma or brain tumor may be beneficial. In infections such as herpes simplex encephalitis, antiviral therapy may help the patient recover.
If brain damage is mild, a person may recover language skills without treatment. However, most people undergo speech and language therapy to rehabilitate their language skills and supplement their communication experiences. Speech and language therapy is the mainstay of care for patients with aphasia.
