Transcranial sonography in depression

Abstract

Transcranial sonography, which displays tissue echogenicity of the brain through the intact skull, reveals reduced echogenicity of the brainstem raphe (BR) as a characteristic finding in unipolar depression and in depression associated with Parkinson's or Wilson's disease, but in general not in healthy adults, bipolar affective disorders, schizophrenia, multiple sclerosis with depression, or Parkinson's disease without concomitant depression. The reason for the reduced echogenicity of the BR is not entirely clear. Magnetic resonance imaging investigations, however, provide evidence that the signal alteration may be caused by a modification of tissue cell density, the interstitial matrix composition, or an alteration of fiber tracts integrity. An involvement of the basal limbic system in the pathogenesis of unipolar depression and depression associated with certain neurodegenerative diseases is assumed.