neurologic disorders
Aphasia
Types of Aphasia
Aphasia is broadly divided into receptive and expressive aphasia. Receptive (sensory, fluent, or Wernicke) aphasia:Patients cannot comprehend words or recognize auditory, visual, or tactile symbols. It is caused by a disorder of the posterosuperior temporal gyrus of the language-dominant hemisphere (Wernicke area). Often, alexia (loss of the ability to read words) is also present. Expressive (motor, nonfluent, or Broca) aphasia:The ability to produce words is impaired, but comprehension and ability to conceptualize are relatively preserved. It is due to a disorder that affects the dominant left frontal or frontoparietal area, including the Broca area. It often causes agraphia (loss of the ability to write) and impairs oral reading. There are other types of aphasia (see table Types of Aphasia ), which may overlap considerably. No aphasia classification system is ideal. Describing the types of deficits is often the most precise way to describe a particular aphasia. 