Anomia

Contents

  1. Definition and Clinical Features
  2. Clinical Examination and Testing
  3. Pathophysiology and Anatomical Correlates
  4. Associated Conditions and Syndromes
  5. References

Definition and Clinical Features

Anomia or dysnomia is a specific deficit in naming or word-finding. In spontaneous speech, this may be detected as abrupt cut-offs, abnormal pausing, the use of circumlocutions (talking around a word), and/or paraphasic substitutions (replacing the intended word with an incorrect sound or related word). Patients may be able to say something about the objects they cannot name (e.g., describing a kite as "flies in the sky"), suggesting preserved access to the underlying semantic system despite an inability to retrieve the specific phonological word form.

Category-specific anomias have also been described, for example, for color, which must be clinically distinguished from perceptual deficits like achromatopsia.

Confrontation naming task showing anomia

In anomia, a patient may easily describe the function of an object but completely fail to retrieve its specific name during confrontation naming tasks.

Clinical Examination and Testing

Formal tests of naming are available and widely used in clinical assessment (e.g., the Graded Naming Test or the Boston Naming Test). During examination, patients may be able to accurately point to named objects despite being unable to name them upon visual confrontation. This dissociation strongly suggests a problem in word retrieval, while demonstrating that language comprehension and object recognition remain intact.

Pathophysiology and Anatomical Correlates

Anomia generally occurs with pathologies affecting the language-dominant (typically left) hemisphere, specifically the left temporoparietal area. However, because naming is a highly complex cognitive process relying on a distributed neural network, word-finding difficulties occur in almost all varieties of aphasia. Consequently, the presence of anomia on its own is of little precise localizing or diagnostic value.

Associated Conditions and Syndromes

The term "anomic aphasia" is reserved for unusual clinical cases in which a naming problem is the primary deficit and dramatically overshadows all other language functions. Beyond isolated presentations, anomia is commonly observed in the following clinical scenarios:

  • As a residual deficit following recovery from more severe types of aphasia (such as Broca's or Wernicke's aphasia).
  • As an early and prominent cognitive feature of Alzheimer’s disease.
  • With any dominant hemisphere space-occupying lesion (such as a tumor, cyst, or abscess) disrupting language networks.

 

References

Benson DF, Ardila A. Aphasia: a clinical perspective. New York: OUP, 1996: 252-261

 

Cross References

Aphasia; Circumlocution; Paraphasia