CLINICAL-AND-FUNCTIONAL ASSESSMENT OF THE EARLY POSTOPERATIVE OUTCOME OF SURGICAL TREATMENT OF PATIENTS WITH VESTIBULAR SCHWANNOMA.

The incidence of vestibular schwannoma (VS) increased largely within the last 50 years from 1,5 cases per 100 thousand persons to 4,2 (for the last decade). The approaches to the management of VS patients vary significantly in different medical centers and different countries. The search for the consensus in selecting strategy of VS treatment based on systemic clinical-and-functional assessment of treatment outcome is topical nowadays. The aim of study - to analyze the clinical-and-functional early postoperative outcome of the surgical treatment of vestibular schwannoma depending on the stage of the disease. The findings of the examination and the outcomes of the surgical treatment of 27 VS patients were retrospectively analyzed. The patients were treated at the Department of Subtentorial Neurosurgery of the State Institution "Romodanov Institute of Neurosurgery of the NAMS of Ukraine" in 2018-2019. According to Koos classification, three groups of the patients were delineated for the analysis of the results of the study, namely, group 1 (Koos II) - 8 (29,6 %) patients; group 2 (Koos III) - 6 (22,2 %); and group 3 (Koos IV) - 13 (48,2 %). The complex clinical examination, in particular clinical-and-instrumental otoneurological examination and the evaluation of the neurological status according to the Scale for the assessment of the functional treatment outcome were performed preoperatively and early postoperatively. The data were statistically processed. In the patients with small tumors (group 1, Koos II), the socially useful hearing on the affected side was preserved preoperatively necessitating the caution for selecting the treatment strategy in these patients. When pre- and postoperative clinical symptoms were compared in group 1, the statistically significant worsening of the hearing to the socially non-useful, the unilateral subjective tinnitus, the dysfunction of the facial nerve, the decreased sense of taste/loss of taste on the anterior 2/3 of the tongue on the affected side were found. Upon the surgical treatment, the rate of the neurological deficit increased, and the severity grade of the neurological deficit increased by about 10 points. The overall preoperative score in group 3 (Koos IV) was significantly different from that in other groups. The progression of the disease to the stage of Koos IV results in the neurological deficit that is equivalent by the set of the neurological symptoms and their severity to that in early postoperative period in patients with Koos III. In group 3, the rate of the dysfunction of the facial nerve and the caudal group of the cranial nerves increased postoperatively with concomitant decreased sense of taste/loss of taste on the anterior 2/3 of the tongue on the affected side and statocoordinatory impairments. The overall preoperative score differed significantly between all groups. In group 3, the postoperative overall score did not differ from preoperative one, although the postoperative overall score in group 3 (Koos ІV) differed significantly from that in other two groups. The proposed scale for the assessment of the functional outcome of the VS treatment is versatile and represents the integral element of the systemic assessment of the clinical-and-functional status of VS patient. There are good reasons to integrate proposed scale into the general scheme of the medical care for VS patients allowing for the objective assessment of the otoneurological patterns in the patients in the dynamics of the treatment. The analysis of our own findings and the literature data proved the relevance of the problem requiring further task-oriented scientific inquiry. The important aspects of the problem relate to the optimization and improvement of the diagnostic and treatment strategy according to the principles of individualization and multimodality allowing for increasing the level of consensus and improving the functional outcome of the treatment.