Aleksandra M. Pavlovic

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Acta Clin Croat,  Vol. 50,  (Suppl) No. 2,  2011 33Acta Clin Croat (Suppl. 2) 2011; 4th international epilepsy symposium in Pula – how to start seizure treatmentTRANSCRANIAL SONOGRAPHY IN DEPRESSIONAleksandra M. PavlovicClinic for Neurology, School of Medicine, University of Belgrade, SerbiaIn patients with depression, brain magnetic reso-nance (MR) scans have detected a number of altera-tions in brain structure compared to those without the illness. In spite some inconsistency in the results, meta-analyses showed that there is a strong evidence for smaller hippocampal volumes, reduction in the left anterior cingulate cortex gray matter and increased load of white matter hyperintensities (WMH). In particular, WMH in depressed individuals have been associated with a late age of onset of the depression and led to the development of the vascular depression theory. Another structure probably critical in depres-sive disorder (DD) is the brainstem raphe (BR), an accumulation of nuclei and fi ber tracts in the mesen-cephalon. BR has important connections with limbic systems, basal ganglia, thalamus, frontal and tempo-ral lobes, hippocampus and cerebellum, and contains ascending and descending fi ber tracts of the medial forebrain bundle, dorsal longitudinal fascicle, mam-milotegmental tract and fasciculus retrofl exus.Th e use of transcranial parenchymal sonography (TCS) enables fast and reliable imaging of BR and other brain midline structures that need to be assessed in patients with DD. Th e method has emerged over the last 15 years as an imporant diagnostic tool in diff erential diagnosis of various movement disorders. Over the years, certain sonograhic feature of the brain midline structures have been recognized as biomark-ers of several diseases. One of the most studied fi nd-ing on TCS is hyperechogenicity of substantia nigra (SN) in idiopathic Parkinson’s disease (IPD). Th e main limitation of the methodology is an inadequate temporal bone window, precluding examination in up to 15% of elderly subjects. Normal BR in healthy persons is seen as a highly echogenic continuous line in the midline of the mesencephalic brainstem, with echogenicity identical to the red nucleus. Pathological fi nding of hypoechogenic BR (hBR) stands for invis-ible, hypoechogenic or interrupted BR line.Depression is not infrequent in neurological dis-orders. DD is detected in up to 70% of patients with IPD, 50% of patients with acute stroke within 6 months of the ictus, up to 50% of patients with vari-ous types of dementia and as many as half of patients with epilepsy. Th e use of TCS in DD provided new insight in the pathogenesis of DD in general. It led to the concept of existence of two subtypes of depression in the regard to the structural changes/lesions local-ization: 1. disorders aff ecting basal limbic system (de-pression in IPD, Wilson’s disease and idiopathic dys-tonia), 2. disorders aff ecting primarily the basal limbic system projections, such as subcortical or subcortical/cortical regions (DD in multiple sclerosis, large isch-emic areas). First TCS studies in patients with unipolar de-pression showed that 50-70% of patients had hBR. Th is fi nding is not related to the age, gender or se-verity of depression but indicates responders to sero-tonine reuptake inhibitors. It aslo probably detects a subpopulation of depressed patients with more severe symptoms (suicidal ideations). In patients with IPD, hBR is seen in up to 85% of patients who were also depressed, and correlates negatively with the degree of motor impairment. Interestingly, hBR appeared to be associated with overactive bladder symptoms in IPD and multiple sclerosis patients. An alteration of BR is also reported in depressed patients with Huntington and Wilson’s disease. TCS of the BR can be particularly useful in dif-ferential diagnosis of DD and parkinsonsim. Depres-sion can be an early, premotor sign of IPD but is also a putative risk factor for IDP. hBR is frequently found in IPD, and correlates negatively with the degree of motor impairment in IPD patients with depression. Acta Clin Croat (Suppl. 2) 2011; 4th international epilepsy symposium in Pula – how to start seizure treatment34 Acta Clin Croat,  Vol. 50,  (Suppl) No. 2,  2011On the other side, in subjects with depression SN hy-perechogenicity correlates with motor asymmetry and reduced verbal fl uency. Furthermore, this interplay is interesting if we have in mind that patients with de-pression are 2-3 times more likely to develop IPD later in life. It is noteworthy that patients with DD have 3 times increased frequency of SN hyperechogenicity, compared to the general population. In summary, TCS fi nding of hBR is frequent in unipolar depression, as well as in DD associated with IPD, Wilson’s and Huntington’s disease. In combina-tion with hyperechogenicity of SN, hBR fi nding can be used to diff erentiate between DD and IPD. TCS use provided new introspection in DD pathogenesis in neurological patients and in general. 

Transcranial Sonography in Depression

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