Objective: Bilateral vestibular loss (BVL) is often diagnosed with great delay and an underlying cause is only identified in 50-80%. We measured horizontal and vertical semicircular canal function using the video-head-impulse test (vHIT) and hypothesized that specific vHIT-patterns may be linked to certain etiologies.Methods: We retrospectively analyzed 109 BVL-patients linked to aminoglycoside vestibulotoxicity (n = 16), Meniere's disease (n = 10), infectious inner-ear disorders (n = 11), sensorineural hearing-loss (n = 11), cerebellar-ataxia-neuropathy-vestibular-areflexia-syndrome (CANVAS, n = 5), other causes (n = 19) as well as those with unknown origin (n = 47). Vestibulo-ocular reflex gains and cumulative saccade amplitudes were measured with vHIT, and the functional integrity of all semicircular canals was rated.Results: Overall, anterior canal hypofunction (n = 86/218) was identified significantly (p < 0.001) less often than horizontal (n = 186/218) and posterior (n = 194/218) hypofunction. Preserved anterior canal function was associated with aminoglycoside vestibulotoxicity, Meniere's disease and BVL of unknown origin, while no such sparing was found for inner-ear infections, CANVAS and sensorineural hearing loss.Conclusions: Semicircular canal function in BVL shows disease-specific dissociations, potentially related to reduced vulnerability or superior recovery of the anterior canals.Significance: In patients with suspected BVL we recommend quantifying vHIT gains and saccade amplitudes for all semicircular canals as the pattern of canal hypofunction may help identifying the underlying disorder. (C) 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

e12533 Background: Primary brainstem tumors (PBST) are the most common neoplasm of central nervous system (CNS) in children. In adults PBST is a rare disease, the incidence was reported to be 5% of CNS primary tumors. Leptomeningeal dissemination (LD) of PBST through the cerebrospinal fluid (CSF) pathway frequently described in childhood is a rare event in adult patients (pts). Methods: In this study we analyzed retrospectively 128 consecutive pts with PBST who referred to the Neurosurgery Department of Verona Hospital ( Italy) between 1998 to 2008. Tumor locations were as follows: mesencephalic area in 25% of the pts, pont in 23%, bulbar region in 45% and bulbar-cervical junction in 6,2%. The histology were: gliomas in 58% of the pts, ependymoma in 22% and other histologic type in 20%. Results: LD was diagnosed in 4.7 % of pts with PBST (6/128), occurring in 2 pts with glioblastoma and 4 pts with grade II astrocitoma. All pts with LD were male, median age was 38 years (28-42), median KPS was 80 (80-100). Radical surgery of primary tumor has been performed in 2 patients, while 4 patients received a subtotal resection. 66% (4/6) of patients have received radiotherapy as treatment of primary tumor and 33% (2/6) received chemotherapy. Median time to LD was 24 months for all patients with PBST. Low-grade tumors had a longer median time to dissemination than high grade tumors (19 vs. 24 months) and patients with gross total resection had longer median time to dissemination than patients with subtotal resection (24 vs. 19 months). Treatment of LD was as follow: 3 patients (33%) received sistemic chemotherapy with temozolomide, 1 patient (16%) received intrathecal chemotherapy with ARA-C, 1 patient (16%) received intrathecal chemotherapy with thiotepa, 1 patient (16%) received a combination of sistemic temozolomide and intrathecal ARA-C and 1 patient received no treatment. Median OS of patients with LD was 24 weeks. Conclusions: In this study we found out a correlation between LD and histologic grading of the tumors, radicality of surgery, therapeutic approaches. Moreover, the treatment of LD had partially modified the evolution of this disease and permitted a better quality of life and good control of the symptoms in patients. No significant financial relationships to disclose.

A case of Marchiafava-Bignami (MB) syndrome with selective callosal involvement was evaluated by clinical examination and magnetic resonance imaging (MRI) in the acute phase and 6 months after the onset of symptoms; at the same time, the corticospinally and transcallosally mediated effects elicited by transcranial magnetic stimulation (TMS) were investigated. The first MRI study showed the presence of extensive abnormal signal intensity throughout the entire corpus callosum. After high-dose corticosteroid administration her symptoms rapidly resolved, in parallel with the reversion of MRI changes, except for severe cognitive impairment. Follow-up TMS examination revealed persistent transcallosal inhibition (TI) abnormalities. This report indicates that the measurement of TI during the course of MB syndrome is useful for evaluating functional changes to the corpus callosum, including their evaluation with time and after treatment and for elucidating the pathophysiology of MB syndrome.

Case Reports Patient 1. An 80 year-old woman was admitted to our department for a sudden onset of a sensorimotor defi cit in her right upper and lower limbs; she also complained of neck pain radiating into her right shoulder. The patient presented a sarcoidosis of the lung with hylar and mediastinal lymphadenopathy, and anterior uveitis, diagnosed in 1994. Sarcoid pathology of noncaseating granuloma with giant cells was detected in the lung biopsy specimen. She was treated with oral steroids for 1 year; for the last 10 years there had been no signs of disease. Neurological examination revealed right-sided hemiplegia and severe hypesthesia over the left side. The plantar response was extensor on the right side. Computed tomography of the brain and cervical spine was normal; magnetic resonance imaging (MRI) of the cervical spinal cord revealed a mass that was extramedullary in the right lateral aspect of the spinal canal at the level C 2 –C 3 and compressing the spinal cord ( fi g. 1 a–c). Surprisingly the plasma level of angiotensin-converting enzyme (ACE) Dear Sir, Sarcoidosis is a chronic systemic disorder of unknown etiology characterized in affected organs by an accumulation of epithelioid granulomas without caseation or staining for infectious agents and derangement of the normal tissue architecture [1] . These granulomas often incorporate multinucleated giant cells and lymphocytes. In the past decade, there has been signifi cant progress in our understanding of the immunopathogenesis of the disease, but the etiology of this enigmatic condition still eludes us. Clinical neurological involvement occurs in approximately 5% of patients. However, autopsy results suggest that subclinical involvement may be present in up to 25% of patients. Neurosarcoidosis is a great mimicker and an uncommon presentation of sarcoidosis; it is therefore a diagnostic challenge, especially when there is no prior history of systemic sarcoidosis [2–8] . A typical imaging feature is thickening and enhancement of the basilar leptomeninges of the brain. Other imaging fi ndings, such as enhancing or nonenhancing parenchymal lesions, dural and bone lesions may occur in the head and spine. Spinal sarcoidosis is a rare condition, whose natural history and therapeutic outcome are still not fully known, and extramedullary extradural mass formation is even rarer. We describe 2 additional cases Received: June 23, 2005 Accepted: October 12, 2005 Published online: January 6, 2006

Congenital anomalies of the internal carotid arteries (ICA) and cerebral arteries have not been frequently reported. Moreover, in the literature there is no clear association between hypoplastic carotid and cerebral vessel systems and the occurrence of cerebral ischaemia. We report two cases of unilateral hypoplasia of the ICA affecting two young patients suffering from an episode of minor stroke and from recurrent transient ischaemic attacks, respectively. Congenital variations in the configuration and size of the carotid and cerebral arteries should not always be considered benign conditions and may predispose to cerebral ischaemia in young adults.

To further investigate the pathophysiology of amyotrophic lateral sclerosis (ALS), the silent period (SP) evoked by transcranial magnetic stimulation during a fatiguing muscle contraction was evaluated in 15 patients and in 15 healthy subjects. Physiological lengthening of the SP duration was not observed in patients with disease duration of ⩾ 2 years. Decreased intracortical inhibition, probably secondary to dysfunction of the inhibitory interneurons that modulate the corticomotoneuronal firing, appears in later stages of disease. Normal motor cortex adaptation is impaired and cortical hyperexcitability might be unmasked during fatigue in ALS patients with longer disease duration.

The effects of theophylline on human corticospinal excitability were studied using transcranial magnetic stimulation (TMS) before and after double-blind oral administration of theophylline or placebo in 20 healthy volunteers. TMS measurements included resting and active motor threshold, silent period, intracortical inhibition (ICI), and intracortical facilitation. F-wave and compound muscle action potential (CMAP) were also measured. Theophylline produces a reduction in ICI, while other parameters of corticospinal excitability remained unaffected. Since ICI is thought to depend on GABAA intracortical inhibitory mechanisms, our data suggest that the increase of human motor cortex excitability is the result of a decrease in GABAergic transmission. Our results further support the hypothesis that theophylline might induce convulsions by inhibiting GABAA receptor binding.