A.V. Korzenev, L.A. Tyutin, A.A. Stanzhevsky, A.V. Pozdnyakov, V.K. Shamrei
(Bekhterev Research Psycho-Neurological Institute, Saint Petersburg
Central Research Institute of Rentgenology and Radiology, Saint Petersburg
Kirov Medicomilitary Academy, Saint Petersburg)
Methods of functional neurovisualization are a cause of cardinal changes in practical psychiatry. They provide more precise (pathogenetic) diagnosis, rational therapy and control of its efficacy. Besides, functional neurovisualization is a turning point in psychosurgery, which lacked objective indications for surgical treatment. One of the ways of solving this problem is PET. Some authors present data on efficacy of PET (with 18F- fluorodesoxyglucose) and functional MRI in diagnosis of psychopathologic changes and estimation of stereotaxic and combined treatment of patients with some neuropsychic disorders.
There were 16 cases with resistant types of obsessive-compulsive disorders and Tourette’s syndrome. All of them underwent PET examination with 18F- fluorodesoxyglucose before and after an intensive course of pathogenetically substantiated psychoparmacotherapy and a year after psychosurgical treatment. Persistent hypermetabolism of glucose in anterior segments of callosal convolutions, orbitofrontal cortex or its reduction in some striatal-limbic structures (heads of the caudate nuclei, thalamic tubercles), which could not be suppressed by subtoxic doses of drugs, was a marker of objective indications for psychosurgical intervention. There was a distinct positive correlation between severity of both metabolic changes and clinical symptoms, watched in patients before and after treatment. These data confirmed the existing information on participation of structures of the limbic-striatal system in pathogenetic mechanisms of development of anxious-obsessive disorders.
It is worth to note, that psychosurgical intervention should be based not only on criteria of severity and resistance of clinical symptoms, but also on data of neurovisualization methods (in particular, PET, functional MRI, etc.). They allow to reveal hyperactive neuronal populations, whose pathologic activity can be overcome by a direct operation only.