Cervical Vestibular Evoked Myogenic Potentials in Idiopathic Intracranial Hypertension.

PURPOSE: Idiopathic intracranial hypertension (IIH) is raised intracranial pressure without any identifiable etiology. The inner ear structures are susceptible to cerebrospinal fluid (CSF) pressure changes because of connections between the CSF space and the labyrinth to explain the audiovestibular symptoms, such as pulsatile tinnitus or dizziness, reported in 50% to 60% of these patients. The aim of this study was to investigate the vestibular functions using cervical vestibular evoked myogenic potentials (cVEMPs) in IIH. METHODS: cVEMPs were recorded in 30 patients with IIH before lumbar puncture. Thirty healthy volunteers constituted the control group. The latencies of peaks p13 and n23 and peak-to-peak amplitude of p13-n23 were measured. RESULTS: Responses were gathered bilaterally from all healthy controls. In 30 patients with IIH, 49 responses could be gathered from 60 tests (81.7%). The potential was absent bilaterally in five and unilaterally in one patient. When recorded, the latency and amplitude values of the responses of the patients were not significantly different from the healthy controls (P > 0.005). A correlation between CSF pressure and response persistence could not be determined. CONCLUSIONS: cVEMPs are affected in patients with IIH and the main finding is the absence of the responses. Increased intracranial pressure causing sound transmission changes within the inner ear can affect the saccular afferents and may end up with absent responses on air-conducted cVEMP recordings. To comment on the correlation between the CSF pressure and cVEMP changes, successive cVEMP recordings with longitudinal CSF pressure monitoring seem necessary.

Incidence and morphology of the accessory head of the flexor pollicis longus muscle (Gantzer`s muscle) in a Turkish population.

OBJECTIVE: To present the incidence, morphology, and the relationships of the accessory head of the flexor pollicis longus (Gantzer`s) muscle (AHFPL) in a recent Turkish population. METHODS: The study was performed on 52 upper extremities of 26 adult Turkish cadavers in the Department of Anatomy, Ege University Faculty of Medicine, Izmir, Turkey in 2005. In our dissections, the prevalence and anatomical morphology of the AHFPL including muscle shape, origin and insertion point, and its relation to the anterior interosseous nerve (AIN) was examined. RESULTS: The AHFPL muscle was found in 27 upper extremities (51.9%). It was bilateral in 10 cadavers (74%), and unilateral in 7 cadavers (26%). The muscle shape was spindle in 19 (70.4%), and papillary in 8 (29.6%). The AHFPL originated from the coronoid process of the ulna in 22 upper extremities (81.5%), and the medial epicondyle of the humerus in 5 cases (18.5%). The AIN passed anterior to the AHFPL in one case (3.7%), lateral in 3 (11.1%), posterolateral in 8 (29.6%) and posterior in 15 (55.6%) cases. CONCLUSION: The knowledge of the morphology and the topography of the AIN and AHFPL is important for understanding the mechanism of the AIN syndrome. The results of this study show the mechanical compression due to the AHFPL may be a cause of the pronator and AIN syndromes.