Cervical and ocular vestibular evoked myogenic potentials in determining nerve division involvement in patients with a tumor located in the internal auditory canal.

OBJECTIVES: The study aimed at the analysis of the parameters of acoustic cervical and ocular vestibular evoked myogenic potentials (AC-cVEMP and AC-oVEMP) response in patients with a confirmed tumor located in the internal auditory canal. It also aimed to assess to what degree a combination of these tests may be of benefit in the preoperative indication of the affected nerve division via preoperative determination whether the tumor originated from the superior or inferior division of the vestibular nerve, both divisions, or if it originated from a different nerve in the internal auditory canal. METHODS: The study group included 50 patients. Preoperative MRI scans were used to measure tumor diameter. AC-cVEMP and AC-oVEMP testing were performed before tumor resection. The surgeon was asked for a detailed description of the tumor origin. RESULTS: The corrected amplitude of cVEMP was significantly lower on the tumor side than on the non-affected side and in the control group. The corrected Asymmetry Ratio (AR) of cVEMPs in patients with the tumor was significantly elevated above the reference values with the mean being 58.29% and the mean AR of oVEMPs in patients the tumor was 71.78% which made both results significantly higher than in the control group. Neither cVEMP nor oVEMP latency was significantly correlated with tumor size. Data obtained from cVEMP and oVEMP tests was an effective indicator of tumor origin in 74% of patients showing which division (or both divisions) of the VIIIth nerve was affected in comparison with information obtained from the surgeon. CONCLUSIONS: The combined use of AC-cVEMP and AC-oVEMP tests may be useful in surgical planning in patients the tumor located in the internal auditory canal, providing a highly probable determination of the division of the affected nerve. Such information is valuable for the surgeon as it offers additional knowledge about the tumor before the procedure. cVEMP and oVEMP results may not be used as the basis for the calculation of tumor size in patients.

Analysis and interpretation of air-conducted ocular vestibular-evoked myogenic potentials (AC-oVEMP) - our experience in healthy adults.

BACKGROUND: Ocular vestibular-evoked myogenic potential (oVEMP) is one of recently introduced tests used to assess the function of the equilibrium system. It is still under research and no consensus has been reached yet. AIM: To analyze AC-oVEMP response parameters in subjects with no history of neurological or vestibular deficits. MATERIAL AND METHODS: The AC-oVEMPs collected from 50 subjects (100 ears) were analyzed in this prospective study for the response presence in the time domain, the latencies and amplitudes of the waves. RESULTS: No statistically significant differences were observed between the right and left ear considering both N1 latency, and amplitude. Significant differences were noted when comparing the groups <40 yo vs ≥40 yo (shorter latencies and higher amplitudes were observed in subjects <40). CONCLUSIONS AND SIGNIFICANCE: This thorough AC-oVEMP analysis in a group of healthy volunteers facilitated the proposal of reference ranges with a simultaneous indication of age-related differences. Shorter oVEMP latencies and higher amplitudes were observed in subjects <40 yo, while in the subjects ≥40 yo the latencies were longer and the amplitudes lower.

Lymphoid tissue neoplasms in the neck region - epidemiological and clinical analysis over 15 years.

AIM: Epidemiological and clinical analysis of lymphoid tissue neoplasms in the neck region over a 15-year period. MATERIAL: There was performed retrospective analysis of 97 patients, aged 17 to 88 years, mean age of 60.3 years. The analysis included data from subjective study, physical examination, image and histopathological studies Results: Almost all cases were lymphoid neoplasms - 95 patients (98%). B cell lymphoma was the most commonly diagnosed lymphoma - 74 cases (76%), followed by Hodgkin's lymphoma- 19 cases (20%). Only two patients had T-cell lymphoma (2%). There was observed prevalence among women, K: M ratio for the whole group was 51: 46, while male predominance was reported in Hodgkin's lymphoma patients (K: M = 7: 12). Over the 15-year period, there was an increase in the number of lymphoid tumors. The most common location on the neck were lymph nodes - 71 (73.2%). Extranodal localizations (26.8%) were most often associated with salivary glands: parotid and submandibular involvement and with the dominant lymphoma of the marginal zone MALT (14 cases). In 57% of patients the fine needle aspiration biopsy (FNAB) results were false, with positive results only in 32% of patients. CONCLUSIONS: Tumors from lymphoid tissue in the neck region are most commonly B-cell lymphomas or Hodgkin,s lymphomas. Non-specific clinical signs and non-specific radiological images, as well as non-diagnostic results o FNAB, make it difficult to effectively differentiate lymphomas with cancer metastasis in neck lymph nodes. Histopathology results of the excised lymph nodes remains a standard for lymphoma diagnosis.