Transcranial sonography in psychiatric diseases

Transcranial sonography (TCS) revealed 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 not in healthy adults, schizophrenia, multiple sclerosis with depression or Parkinson's disease without concomitant depression. Similar findings were shown also for adjustment disorder with depressed mood. In contrast to unipolar depression, sonographic findings of bipolar patients may generally indicate preserved structural integrity of mesencephalic raphe structures. If bipolar disorder is associated with hypoechogenic BR, depressive symptoms are more severe. BR hypoechogenicity could be caused by a modification of tissue cell density, the interstitial matrix composition or an alteration of fiber tracts integrity representing involvement of the basal limbic system in the pathogenesis of unipolar depression and depression associated with certain neurodegenerative diseases.Recently it was shown that nigrostriatal dopaminergic system is abnormal in children with attention-deficit hyperactivity disorder which was expressed by significantly larger echogenicity of substantia nigra.The increasingly broad application of TCS in the early and differential diagnosis of neurodegenerative and psychiatric disorders in many centers all over the world is probably the best evidence for the value of the method. Main advantages include the easy applicability, the fact that it is quick and repeatedly performable with no limitations as known from other neuroimaging techniques and that it is relatively cheap and side effect free.