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Highlights • In Berrettinni anastomosis, frequently a sensory communicating branch from ulnar nerve supplies digit 3. • Despite anatomical evidence of ulnar communicating branch providing sensory supply to digit 2, there are no electrodiagnostic descriptions of the same. • Electrodiagnostic findings in a patient with median nerve laceration were suggestive of ulnar sensory innervation of digit 2. • Knowledge of existence of these communications and their electrodiagnostic features can prevent misdiagnosis and iatrogenic injuries., Introduction Berrettini Anastomosis is a common purely sensory anastomosis between ulnar and median nerves in palm. Here, via a communicating branch, ulnar nerve can provide sensory supply to digits 3 and 2.There have been electrodiagnostic (EDX) descriptions of the former. However, till date, to the best of our knowledge, there have been no EDX descriptions of the latter. Here, in our case report we would like to describe first instance of the same. Presentation of case During an assault with a knife a 25-year-old male sustained laceration injury of right median nerve and flexor tendons which were repaired surgically. During rehabilitation, a nerve conduction study (NCS) was performed which incidentally revealed that ulnar nerve was responsible for sensory innervation of digit 2. Discussion Until recently, it was generally believed that EDX of BA was not possible. However, recent studies on EDX features in BA, have recorded small sensory nerve action potentials (SNAP) from digit 3 on distal ulnar nerve stimulation. But there are no published reports where SNAP from digit 2 on ulnar nerve stimulation were studied, even though anatomical evidence of the same exists. In our patient, we incidentally recorded the same. Conclusion Although our patient had a complete laceration of median nerve, he did not have major sensory disturbances. NCS findings suggested sensory supply of digits 5, 4, 3 and 2 were by ulnar nerve. Without adequate knowledge of communicating branch crossovers in palm, there is a possibility that clinical findings can be misdiagnosed and NCS features can be misinterpreted. For surgeons, awareness of these communicating branches can prevent iatrogenic injuries during surgical interventions.

Highlights • These guidelines provide orientation to perform clinical neurophysiological studies during COVID-19 pandemic. • Guide to perform protective procedures for healthcare personal doing clinical neurophysiological studies. • Offer a protocol for the disinfection of equipment and supplies in clinical neurophysiological studies., On 31st December 2019, China notified the World Health Organization of an outbreak of atypical pneumonia from patients at a local seafood market in Wuhan, Hubei, China, responsible for a new coronavirus called Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that caused COVID-19 disease, which spread rapidly around the world. WHO declared a state of pandemic (11th March, 2020), which has caused more than 1 million infected and more than 110,000 deaths; it was observed that up to 29% of those infected were health care personnel. The main route of transmission of SARS-CoV2 is through respiratory secretions and direct contact with contaminated surfaces and material. The pandemic induced an international saturation of health care services and a rupture in the supply chain of protective equipment for healthcare personnel, which poses a high occupational risk to all. Based on the different healthcare systems, human resources, infrastructure and medical emergencies that will warrant the conduct of clinical neurophysiology studies and the lack of a guide for the management of the situation, it was decided by an expert task force of the Latin American Chapter of the International Federation of Clinical Neurophysiology to carry out these guidelines for the protection of patient and healthcare professionals conducting clinical neurophysiological studies.

Background During the era of the Coronavirus disease 2019 (COVID-19) pandemic, various neurological syndromes were reported during or after the infection. Fortunately, efforts were made to successfully develop various vaccines with high efficacy and safety. Despite the promising results of those vaccines, they are too novel to be fully understood. Here we are shedding light on a neurological case presentation that may be attributed to one of the COVID-19 vaccines. Case presentation A 23-year-old male patient with no prior comorbidities presented with quadriparesis and numbness that were clinically and electrophysiologically consistent with Guillain-Barré Syndrome (GBS). The condition started 10 days after the first dose of the AstraZeneca vaccine. Moreover, MRI of the brain and spinal cord has shown evidence of non-specific central demyelination. Despite the radiological finding, the patient is not fulfilling the diagnosis of a known demyelination disorder and the lesions regressed on follow-up. Since no better explanation or trigger could be found, a post-vaccination immune-mediated reaction was considered. Conclusion We still cannot assume the certainty of the causality association between the vaccine and the neurological presentation. Meanwhile, we suggest vigilance for cases of GBS or myelitis following vaccination for Covid-19 and that post-vaccination surveillance programs ensure a statistically significant tool to prove or dispsrove the causality.

Highlights • The median and ulnar nerves can be recorded consecutively or simultaneously to diagnose carpal tunnel syndrome. • Simultaneous and consecutive recording of the median and ulnar nerves sensory latency have a poor agreement. • Technical variations can have diagnostic consequences., Objective To assess if recording the sensory latencies of the median and ulnar nerves one-by-one (consecutive) or at the same time (simultaneous) in the ring-finger test for carpal tunnel syndrome (CTS) will show equivalent results or if it will lead to a different clinical classification of patients. Methods We assessed the limits of agreement between the simultaneous and the consecutive method based on the median- ulnar sensory latency difference derived by both methods in 80 subjects and compared the number of minimal CTS cases identified by the two methods. Results Limits of agreement ranged from −0.23 to 0.29 ms. A significantly higher proportion of subjects with minimal CTS (only detectable by using the comparison test) was found using the simultaneous method (n = 8 and 2, respectively; p = 0.03). Conclusion The two methods have a poor to moderate agreement as indicated by the range of the limits of agreement (0.5 ms). Significance Even small methodological changes to the ring-finger test can lead to results with different clinical meaning in the same individual and one should be aware of which method was used when interpreting results.

In recent years, enterovirus D68 (EV-D68) has advanced from a rarely detected respiratory virus to a widespread pathogen responsible for increasing rates of severe respiratory illness and acute flaccid myelitis (AFM) in children worldwide. In this review, we discuss the accumulating data on the molecular features of EV-D68 and place these into the context of enterovirus biology in general. We highlight similarities and differences with other enteroviruses and genetic divergence from own historical prototype strains of EV-D68. These include changes in capsid antigens, host cell receptor usage, and viral RNA metabolism collectively leading to increased virulence. Furthermore, we discuss the impact of EV-D68 infection on the biology of its host cells, and how these changes are hypothesized to contribute to motor neuron toxicity in AFM. We highlight areas in need of further research, including the identification of its primary receptor and an understanding of the pathogenic cascade leading to motor neuron injury in AFM. Finally, we discuss the epidemiology of the EV-D68 and potential therapeutic approaches.

Highlights • The active recording electrode site influences the CMAP waveform of the trapezius muscle (TM). • CMAP becomes high by placement of the active recording electrode 2 cm behind the belly of the TM. • Volume conduction from the supraspinatus muscle affects the CMAP waveform of the TM., Objective We investigated how the active electrode placement site influences compound muscle action potential (CMAP) configuration of the upper trapezius muscle (TM). Methods A nerve conduction study of the accessory nerve was performed, and the CMAPs obtained with two different placement sites, i.e., placement of the active recording electrode on the belly of the upper TM (CMAP-A) and placement of the electrode 2 cm behind the belly (CMAP-B), were compared. CMAPs were also obtained with the active recording electrode placed in the supraspinous fossa (CMAP-C). Results All CMAPs were recorded from 21 healthy volunteers. The mean peak-to-peak amplitude of CMAP-B was 3.4 mV higher than that of CMAP-A (11.0 ± 4.0 mV vs. 14.4 ± 4.9 mV; P

Background Cross-sectional area (CSA) measurement of the ulnar nerve in the adult population by using ultrasonography (US) at elbow extension and flexion has previously been reported, but not much evidence showed a significant difference between elbow extension and flexion position. Purpose To compare the ulnar nerve CSA between elbow extension and flexion position. Methods A comparative cross-sectional study was conducted by involving 36 healthy adults with normally functioning ulnar nerve proven by Nerve Conduction Study (NCS) or Electroneurography. The ulnar nerve CSA was measured on each elbow by using US at the level of the medial epicondyle, 2 cm distal and 2 cm proximal from the medial epicondyle. Results The average ulnar nerve CSA at the medial epicondyle, 2 cm distal and proximal to the medial epicondyle at elbow extension respectively were 5.95 ± 0.74 mm2, 6.27 ± 0.92 mm2, and 5.92 ± 0.73 mm2. At elbow flexion, the average ulnar nerve CSA at the positions was 5.70 ± 0.83 mm2, 5.23 ± 0.87 mm2, dan 5.73 ± 0.71 mm2 respectively. The CSA of the ulnar nerve at elbow extension was significantly larger compared to the flexion position in the three areas observed in this study (p Conclusion The CSA of the ulnar nerve at elbow extension position was larger compared to the flexion position. Elbow position should be considered in measuring CSA of the ulnar nerve.

Highlights • Serial T-reflex study is useful to reveal reversible conduction failure in early GBS. • T-reflex is useful for diagnosis of GBS in the early stages of the disease. • The combination of nerve conduction studies and T-reflex improves GBS diagnosis., Objective To describe the case of a patient with Guillain-Barré syndrome (GBS) showing early reversible conduction failure (RCF) detected by means of serial deep tendon reflex response (T-reflex) study. Methods A 36-year-old woman had a 5-day history of foot and hand paresthesias ascending to thighs and arms, throbbing interscapular and neck pain, mild to moderate tetraparesis, and areflexia. Nerve conduction studies (NCS) were performed on days 7 and 33 after onset. Results NCS showed an equivocal electrophysiologic pattern, just an isolated distal RCF being detected on the right radial nerve at initial examination. Motor latency on deltoid muscle after Erb’s point stimulation was preserved. Sensory conduction velocities were normal or slightly slowed. Somatosensory evoked potentials from median and tibial nerves were normal. Initially, F-wave study demonstrated reversible abnormalities, consisting of multiple A waves and low F-wave persistence, minimal F-wave latencies being preserved. Biceps brachii T-reflex was normal, whereas Achilles T-reflex was absent bilaterally, appearing on the second study with normal T-wave morphology and latency, thus conforming to the requirements for RCF diagnosis. Soleus H-reflex was also initially absent. Conclusions Serial T-reflex study is a useful technique for detecting early RCF of proximal nerve trunks in early GBS. Significance T-reflex is useful tool for GBS in association with NCS.

INTRODUCTIONSchwannomas are benign, encapsulated, slow-growing and usually solitary tumors originating from Schwann cells of the peripheral nerve sheath. Schwannomas of the superficial peroneal nerves are very rare, and therefore scarcely documented in the literature. The authors report a case of a diagnosed superficial fibular nerve sheath tumor with an unreported clinical presentation.PRESENTATION OF CASEA 52-year-old Caucasian female arrived to our Orthopedics Department complaining of pain and numbness of the lateral aspect of her left leg. These symptoms were present for a year and were more evident at the end of the day, or after a long time in the orthostatic position. No evidence of other medical illnesses was found. There was no record of prior traumatic events related to that limb. Diagnosis of a benign peripheral nerve tumor was achieved and the patient was treated by surgical excision of the lesion.DISCUSSIONThe intermittent symptomatology presentation on this case suggest a mechanical compression etiology, allied to classical pain and paresthesia often exhibited by this kind of the tumor. An intracompartimental pressure elevation could explain why the symptoms disclosed an episodic pattern, due to a constricted, inclosed nerve.CONCLUSIONWe describe a rare case of a patient with an unusual superficial peroneal nerve Schwannoma clinical presentation. Literature on this topic is scarce and, therefore, this case report intends to add further data about this kind of lesion.