A37 The role of technicians in ultrasound examinations of peripheral nerves and muscles

Abstracts / Clinical Neurophysiology 128 (2017) e178–e303

A35 TRNS effects on multiple sclerosis symptoms: A randomized double-blind sham-controlled trial—Moussa A. Chalah 1, Ulrich Palm 2, Jean-Pascal Lefaucheur 1, Samar S. Ayache 1 (1 Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, EA 4391, Faculty of Medicine, Paris Est University-Physiology Department, Henri Mondor Hospital, Créteil, France, 2 Klinikum der Universität München, Institut für klinische Neuroimmunologie, Munich, Germany) Objectives: Nowadays, there is a growing interest in investigating the potential role of noninvasive brain stimulation (NIBS) techniques in several neuropsychiatric diseases. Among the latter, multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system, can result in a variety of difficult-to-treat symptoms. The aim of this work is to assess the effects of transcranial random noise stimulation (tRNS), an NIBS technique, on frequently encountered and challenging MS-related symptoms, namely neuropathic pain, cognition, mood, and fatigue. Methods: 16 MS patients were enrolled. Each patient randomly underwent two stimulation blocks (active or sham) over the left dorsolateral prefrontal cortex. Each block consisted of three consecutive daily sessions. The evaluation consisted of the Attention Network Test, Visual Analogue Scale for pain, Neuropathic Pain Inventory, Hospital Anxiety and Depression Scale, Modified Fatigue Impact Scale, as well as neurophysiological measures for pain and cognition (Pain related evoked potentials, frontal midline theta activity). Results: Compared to sham stimulation, a trend towards pain improvement was obtained following the active tRNS as documented by a decrease in pain scores and N2-P2 amplitudes of pain related evoked potentials. Active tRNS did not have any effects on frontal midline theta activity, attention, mood or fatigue scales. Discussion: The absence of effects on other symptoms might be related to sample size and short protocol duration. Conclusions: tRNS seem to induce analgesic effects in MS related neuropathic pain. Significance: tRNS might play an important role in pain management especially in situations where pharmaceutical agents are faced with limited benefits. Keywords: Multiple sclerosis, Transcranial random noise stimulation, tRNS, Dorsolateral prefrontal cortex, Pain, Attention doi:10.1016/j.clinph.2017.07.046

A36 Methodology for recording reliable wrist extensors and wrist flexors compound muscle action potentials—Joao Leote 1, Michela Campolo 2, Larisa Pascan 3, Tânia Marques 3, Verónica Teixeira 3, Jordi Casanova-Molla 2, Josep Valls-Solé 2 (1 Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Neurosurgery Department, Hospital Garcia de Orta, Almada, Portugal, 2 Unitat d’Electromiografia, Servei de Neurologia, Hospital Clínic, Universitat de Barcelona, IDIBAPS (Institut d’Investigació Biomèdica August Pi i Sunyer), Neurology, Barcelona, Spain, 3 Escola Superior de Tecnologia da Saúde de Lisboa. Instituto Politécnico de Lisboa, Neurofisiologia, Lisboa, Portugal) The electrophysiological examination of wrist extensor (WE) and wrist flexor (WF) muscles is often part of the overall evaluation or therapy of patients with weakness due to central or peripheral disorders involving the motor pathway. Unfortunately, though, the WE and WF compound muscle action potentials (CMAPs) have often an irregular shape and multiple phases. This would require measuring the area of the response in order, for instance, to quantify the proportion of corticospinal tract fibers activated by transcranial

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magnetic stimulation (TMS) with respect to the pool of spinal motoneurons, which would lead to the CMAP. However, unpredictable phase cancellation and shape inconsistency may lead to equivocal results. It would be desirable to obtain CMAPs and MEPs in WE and WF of large amplitude and little dispersion, to reach comparable data within and between subjects. Objective: Determine the best location, size and interdistance for the recording electrodes over the WE and WF muscles, and calculate the proportion of excitable corticospinal fibers activated with TMS in healthy volunteers. Methods: We conducted the study in 16 subjects. We recorded the MEPs in various recording sites along the dorsal and ventral sides of the forearm, over the WE and WF muscles, respectively. We used circular adhesive electrodes (i.e diameter of 20 mm), 2.5 cm apart (controls) or 35  45mm rectangular electrodes referenced 2.5 cm apart from active or above wrist extensor retinaculum. Latencies, amplitudes, duration and turns of evoked MEP were compared. Results: We used 130% above threshold intensity and analyzed a mean of 10 MEPs in each site. The WE and WF CMAPs recorded using larger electrodes with reference at the wrist showed greater amplitude and duration, and less number of turns. Conclusions: The muscle area and their insertion sites can in part explain the waveform of MEP’s. For laboratory recordings, the surface electrodes should have the appropriate size for the target muscle allowing more ‘‘regular” CMAPs. Keywords: Wrist flexores, Wrist extensors, CMAP, TMS doi:10.1016/j.clinph.2017.07.047

A37 The role of technicians in ultrasound examinations of peripheral nerves and muscles—Gregor Omejec (University Medical Center Ljubljana, Institute of Clinical Neurophysiology, Ljubljana, Slovenia) Objectives: Neurophysiological technicians offer an important assistance to neurologists in performing electrodiagnostic (EDx) studies. Furthermore, in most places they are autonomous in carrying out nerve conduction studies, EEG and evoked response recordings. Methods: Ultrasonography (US) of peripheral nerves and muscles is rather new diagnostic method. Therefore, the role of technicians in US examinations is not fully determined. Results: Our laboratory for US of peripheral nerves and muscles has 7 years of experience performing routine clinical and research practice. In 2016 we performed 466 US examinations, mainly for evaluation of entrapment/compression neuropathies (carpal tunnel syndrome (CTS) - 108 (23%) and ulnar neuropathy at the elbow (UNE) - 204 (43%). Other pathologies include nerve traumas, tumors and inflammatory or hereditary neuropathies. Discussion: The responsibility of neurophysiological technician is patients’ requests and appointments and correctly positioning the patient before the examination. Furthermore, technician is autonomous in performing well defined examinations (i.e. evaluation of the CTS and UNE) and must be able to take history and focused neurologic examination. Medical exam is finally prepared and interpreted by neurologist. To properly perform such studies technician should have thorough knowledge of human anatomy, physiology and pathophysiology of peripheral nerves and muscles. Skills should be obtained in scanning nerves transversely and longitudinally in order to select and capture the best image possible. Conclusions: Although not fully determined, we believe the role of US technician is important. Not only to assist neurologist but also to

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independently perform well defined and simple examinations, which are typically the most common. Keywords: Peripheral nerves, Ultrasonography, Technicians doi:10.1016/j.clinph.2017.07.048

A38 Physiotherapy of carpal tunnel syndrome—Eva Fricz (Centre Hospitalier de Denain, Department of Physiotherapy, Denain, France) Objectives: Carpal tunnel syndrome (CTS) is a widely distributed upper limb nerve compression. CTS is relatively easy to recognise with timely diagnosis of symptoms. The elimination of risks and professional conservative therapy can prevent the radical interventions. Methods: In our study we worked with 8 patients, 7 of them had signs of CTS in both hands. The diagnosis was based on history, physical examinations and an electroneurographia test (ENG). All of the patients completed a questionnaire about their subjective symptoms before the objective physical examinations. The used physiotherapy was modified for the severity of the symptoms. Advice on workplace task modification was given to all patients. Results: Main symptoms are tingling, numbness, nocturnal pain and weakness in the distribution of the median nerve in the hand. Objective results represented a decrease in the range of motion, waste of force in the hand and thenar atrophy. After the treatment the waste of the abductor pollicis has disappeared in all patients, weakness and deficits of motion were found in one person. We recognised a significant improvement in the specific tests. Discussion: Occupational factors, overstrain of the hands are important causes of CTS. Loss of sensory feedback and pain is more often presented than motor function loss. After the treatment the symptoms of patients were reduced or disappeared. Conclusions: CTS can be often effectively treated with complex physiotherapy and workplace task modifications, but there isn’t a complete recovery in all cases. Keywords: Carpal tunnel syndrome, Physiotherapy, Conservative therapy, Symptoms of CTS, Occupational risks of CTS

urinary incontinence, erectile dysfunction, diarrhoea and constipation, carpal tunnel syndrome, cardiac and renal involvement. As a result the phenotypic heterogeneity and limited awareness among physicians especially in non-endemic areas make the diagnosis challenging. Keywords: Transthyretin, Familial amyloid polyneuropathy, Polyneuropathy doi:10.1016/j.clinph.2017.07.050

S40 Diagnosis and follow-up of TTR-FAP: Common misdiagnoses—Yesßim Parman (Istanbul University, Department of Neurology, Istanbul, Turkey) Transthyretin familial amyloid polyneuropathy (TTR-FAP) is a highly disabling, life threatening disease characterized by progressive sensorimotor and autonomic neuropathy. The profile of the disease is inadequately understood at present. Variable clinical features, lack of awareness among physicians and limited access to genetic screening can all contribute to high rates of misdiagnosis and poorer patient outcomes. Existing treatment options and emerging therapies opened a new era in the management of TTR-FAP. Time to diagnosis can be more than 4 years especially, in non-endemic areas. The common misdiagnoses include diabetic neuropathy which is sensory neuropathy with small fiber predominance and autonomic symptoms and signs. TTR-FAP should be kept in mind in CIDP cases not responding to conventional immunosuppressives and IVIg treatment. Idiopathic axonal neuropathies constitute a large group of undiagnosed polyneuropathies. A thorough investigation, including missing points of the family and patient history can lead to TTRFAP diagnosis in some cases. AL amylodosis can also be confusing in the elderly. Other differential diagnosis possibilities include HSAN, Fabry’s disease and leprous neuropathy. As ATTR is an irreversible and progressive disease, diagnosing patients and initiating treatment as early as possible are essential. Delay in the time to diagnosis is a major obstacle to the optimal management of TTR-FAP.

doi:10.1016/j.clinph.2017.07.051

doi:10.1016/j.clinph.2017.07.049

Symposium II. – Familial Amyloid Polyneuropathy (FAP): All aspects of the disease from diagnosis to treatment S39 Familial amyloid polyneuropathy (FAP): All aspects of the disease from diagnosis to treatment: Disease description: What is FAP?—Sevim Erdem Özdamar (Hacettepe University, Neurology, Ankara, Turkey) Transthyretin familial amyloid polyneuropathy (TTR-FAP) is a rare autosomal dominant disorder induced by the deposition of the mutated TTR protein as amyloid fibrils. It is a multisystemic disorder affecting several organs including but not limited to peripheral nerves, heart, kidneys and eyes. Although it is well known in endemic countries like Portugal, Japan and Sweden sporadic cases have been defined all over the world. The age of onset varies across different populations and can be as early as the second and as late as the ninth decades of life. Likewise the phenotypes are not uniform, even the most common mutation Val30Met can present with different phenotypes. The most common clinical signs and symptoms are peripheral neuropathy associated with orthostatic hypotension,

S41 What are the electrophysiological pitfalls in FAP?—Gorkem Sirin (Bakirkoy Prof. Dr. Mazhar Osman Training and Research Hospital for Psychiatric, Neurologic and Neurosurgical Diseases, Department of Neurology, Istanbul, Turkey) Introduction: Familial amyloid polyneuropathy (FAP) is an autosomal dominant disease characterized by endoneurial amyloid deposits. Transthyretin FAP (TTR-FAP) is the most common type. The major clinic presentation of TTR-FAP is a progressive length dependent axonal sensorimotor and autonomic neuropathy. Methods: Electrophysiological studies used in the diagnosis and follow-up are viewed. Results: A standard electromyography (EMG) study consists of sensory and motor nerve conduction studies as well as late responses when assessing FAP. EMG studies are important in many aspects in the evaluation for FAP. In asymptomatic patients, neurological screening at periodic follow-up includes EMG. Early signs of peripheral nerve involvement like reduced sensorial nerve action potentials predominantly in lower extremities or typical manifestations like carpal tunnel syndrome can lead to decide the initiation of disease-modifying treatments. As the disease progresses, EMG studies commonly reveal symmetric motor and sensorial axonal degeneration. Asymmetric involvement is a rare clinical presentation.