Us and Mri Neurography Assessment of Diagnostic Criteria in Patients With Carpal Tunnel Syndrome Using Electrophysiological Tests as Gold Standard: A Prospective Study

BackgroundPeripheral neuropathy evaluation depends mainly on physical examination, patient history, electrophysiological studies, with evoked potential abnormalities. High-resolution US has the advantage of being fast, non-invasive modality with nerve dynamic assessment allowing examination of long part of nerve. MR imaging serve better in examination of deeper nerves with higher contrast resolution. It shows great benefit in patient with atypical presentation, Equivocal diagnosis and suspicious of secondary cause and post-surgical relapse.MethodsThis study was conducted prospectively on 32 patients, presented with carpal tunnel syndrome diagnosed by electrophysiological tests. Superficial US of the wrist joint was done to all participants followed by MRI within 1 weeks of the US.We aimed to assess the measurements & criteria of both US & MRN in diagnosis of CTS, depending mainly on the three-measurement assessed by Buchberger et al., then to find the agreement between US & MR Neurography (MRN)ResultsUs proved to have higher rate of CTS prediction, the three main parameters CSA measurement, distal nerve flattening and flexor retinaculum bowing indices showed positive occurrence of 93.7%,59.4% &59.4% respectively. While we found that decreased nerve echotexture was positive in 90.6% of patients.Regarding MRI it showed less diagnostic ability when using CSA measurement as it was positive in 81.2% of patients, also distal tunnel nerve increased flattening and bowed flexor retinaculum positive results were slightly decreased to 56.2% for each. In contrast to high T2 signal of median nerve which was positive in 90.6% of patients.In agreement study, we found statically significant difference supporting US as the primary diagnostic modality of CTS depending mainly on the three measurement CSA, Flattening and bowing indices. Yet, for cases of secondary CTS and detection of underlying entrapping cause as well as innervated muscle early abnormality detection and better tissue characterization, MRI was better diagnostic modality with statistically significant difference. ConclusionsOur results proved that ultrasound examination can be used as first imaging modality after physician evaluation with comparable results to electrophysiological studies in evaluating CTS and try to find the cause. MRN examination came as second step in patients with suspected muscle denervation changes that could not be elicited by US or equivocal cases for detection of secondary cause in clinically suspected patient.

A personalized approach to preclinical diagnosis and initial therapy of primary glaucoma based on a comprehensive structural and functional examination. A clinical case

The principles of personalized approach to early diagnosis and monitoring of primary glaucoma are shown by a clinical example. We analyzed the potentials of contemporary electrophysiological tests for preclinically diagnosing glaucoma optic neuropathy and monitoring drug treatment. For the first time, we demonstrated the experience of using a new fixed combination of brinzolamide + brimonidine by a clinical case from our practice. The test results confirm the hypotensive effect of the medication (IOP reduction by 36.2 %) so that it can be recommended for the treatment of patients with glaucomatous optic neuropathy and that combined with vascular pathology.

Habituation to a Deterrent Plant Alkaloid Develops Faster in the Specialist Herbivore Helicoverpa assulta Than in Its Generalist Congener Helicoverpa armigera and Coincides with Taste Neuron Desensitisation

The two closely related moth species, Helicoverpa armigera and H. assulta differ strongly in their degree of host-plant specialism. In dual-choice leaf disk assays, caterpillars of the two species that had been reared on standard artificial diet were strongly deterred by the plant-derived alkaloid strychnine. However, caterpillars of both species reared on artificial diet containing strychnine from neonate to the 5th instar were insensitive to this compound. Fifth instar caterpillars of H. assulta and 4th or 5th instars of H. armigera not exposed to strychnine before were subjected to strychnine-containing diet for 24 h, 36 h, 48 h, or 72 h. Whereas H. assulta displayed habituation to strychnine after 48 h, it took until 72 h for H. armigera to become habituated. Electrophysiological tests revealed that a deterrent-sensitive neuron in the medial sensillum styloconicum of both species displayed significantly reduced sensitivity to strychnine that correlated with the onset of habituation. We conclude that the specialist H. assulta habituated faster to strychnine than the generalist H. armigera and hypothesis that desensitization of deterrent-sensitive neurons contributed to habituation.

Incidence and clinical feature of Myasthenia gravis: A five-year data analysis in Ulaanbaatar, Mongolia

Myasthenia gravis (MG) is a rare neuromuscular disorder. Till now, there are no studies on the prevalence and incidence of MG in Mongolia. The current study aimed to elucidate the incidence of MG in Ulaanbaatar, the age of onset, and the gender distribution of Mongolian patients with MG. We conducted a cross-sectional, hospital-based study involving MG patients (n=48) all around Ulaanbaatar from 1 January 2015 to 1 January 2020. The clinical diagnosis was assessed with the Myasthenia Gravis Foundation of America (MGFA) classification system. The disease severity was evaluated by using Osserman’s classification. The diagnosis was confirmed with serological and electrophysiological tests. Statistical analysis was performed using SPSS software. A total of 30 patients with MG were registered for the last five years in Ulaanbaatar. The average annual incidence of MG in Ulaanbaatar was 0.65 per 100,000 populations (95%CI 0.26-1.34), 0.60 in males (95%CI 0.25-1.28), and 0.69 in females (95%CI 0.33-1.46). The cumulative incidence in the study period was 3.2 per 100,000 populations. The ratio of males to females was 1:1,3. The median age for onset of MG was 33 years (ranging from 27 to 46 years); 43.3% of patients had ocular and 56.7% generalized symptoms at the disease onset. Only 23.3% of patients remained with purely ocular symptoms (Osserman I stage). The average incidence of MG between 2015 and 2020 was 6,5 per 1.000.000 population, and the annual incidence was relatively stable. Although ocular and generalized symptoms were observed each in about half of the cases, only one-fourth remained with pure ocular signs at the end of the review period.

Systematic review and meta-analysis on the effect of continuous subjective tinnitus on attention and habituation

Background Attention and habituation are two domains known to play key roles in the perception and maintenance of tinnitus. The heterogeneous nature of tinnitus and the methodologies adopted by various studies make it difficult to generalize findings. The current review aims at assessing and synthesizing evidence on the possible roles of attention and habituation in continuous subjective tinnitus. Methodology The literature search included five databases (PubMed, Scopus, Web of Sciences, CINAHL and ProQuest) that resulted in 1,293 articles, published by July 2019. Studies on attention and/or habituation in individuals with tinnitus using either behavioural or electrophysiological tests were included in the review after a quality assessment. Results Seventeen studies on attention in tinnitus were included in the narrative synthesis. Two meta-analyses were performed to assess the role of attention in tinnitus using a behavioural methodology (z = 4.06; p < 0.0001) and P300 amplitude (z = 2.70; p = 0.007) with 531 participants. With respect to habituation, the review indicates the lack of quality articles for habituation inclusion in the narrative synthesis. Conclusions The review highlights that selective domains of attention were consistently impaired in individuals with tinnitus. Habituation, on the other hand, needs further exploration.

Post COVID-19 Guillain Barre Syndrome in Immunocompromised Children - A report of two cases and review of literature

IntroductionSevere acute respiratory syndrome Coronavirus 2 (SARS-CoV 2) is a novel coronavirus that caused an outbreak since 31 December 2019. Although the most commonly noted symptoms were fever and respiratory illness, a wide variety of other symptoms have also been seen. There has been increasing number of cases of neurological manifestations of Covid –19. Further, there has been growing association between Covid-19 and Guillain Barre Syndrome (GBS).Case presentationIn this report, we present two cases of acute lymphoblastic leukemia affected by Covid-19 who after recovery from Covid-19 developed symptoms of GBS. They presented with complaints of bilaterally symmetrical ascending motor paralysis and were diagnosed with Guillain Barre Syndrome by electrophysiological tests and were started on intravenous immunoglobins for five days @ 0.4mg/kg/day after which the condition of both children gradually improved.ConclusionThis case report adds to the emerging evidence that suggests the association of GBS post Covid infections. COVID-19 can result in several autoimmune neurological phenomena including GBS. In the setting of the pandemic, COVID-19 as an underlying trigger should be considered in all immunologic phenomena. This applies to all patients, including children.

Diagnostic Evaluation of Visual Snow

Introduction: To determine which patients with visual snow (VS) and VS syndrome (VSS) require standard ophthalmologic testing including automated visual field and which patients require further testing such as macular spectral domain optical coherence tomography (SD-OCT), electrophysiology, and neuroimaging.Materials and Methods: We retrospectively reviewed 52 consecutive patients at three institutions with VS and VSS including the University of Alabama, Callahan Eye Hospital, the University of Missouri-Kansas City School of Medicine, and the Little Rock Eye Clinic from the years 2015 to 2021. We collected historical information, examination findings, ophthalmic testing, electrophysiology, and neuroimaging.Results: Of the 52 patients with VS and VSS, eight of the 52 cases met the clinical criteria for VSS. The ages ranged from 7 to 79 years, with a mean age of 25 years (SD = 14.0). There were 22 males and 30 females. Color vision was tested in 51 cases and was normal in 47 cases (92%). A funduscopic exam was performed in all 52 cases and was normal in 46 cases (88%). The macular SD-OCT was normal in all of the 19 cases that it was performed (100%). A Humphrey visual field was performed in 50 cases and was normal in 43 (86%). A visually evoked potential (VEP) was normal in 18 of the 19 cases where it was obtained (95%). The full-field electroretinography (ffERG) was obtained in 28 cases and was normal in 25 (89%). The multifocal electroretinography (mfERG) was normal in 11 of 12 cases (92%). Only four patients accounted for all of the abnormal electrophysiological tests. In the 37 cases that had an MRI, 29 were normal (78%). Only one patient revealed a lesion in the visual pathway (right optic nerve enhancement in an optic neuritis patient).Conclusions: Patients with VS and VSS, if typical in presentation and with normal testing, do not require a workup beyond a thorough history, neuro-ophthalmologic examination, and automated perimetry. If this testing is abnormal, then ancillary testing is required.

Clinical prediction rules for the diagnosis of neuritis in leprosy

Background Diagnosing neuritis in leprosy patients with neuropathic pain or chronic neuropathy remains challenging since no specific laboratory or neurophysiological marker is available. Methods In a cross-sectional study developed at a leprosy outpatient clinic in Rio de Janeiro, RJ, Brazil, 54 individuals complaining of neural pain (single or multiple sites) were classified into two groups (“neuropathic pain” or “neuritis”) by a neurological specialist in leprosy based on anamnesis together with clinical and electrophysiological examinations. A neurologist, blind to the pain diagnoses, interviewed and examined the participants using a standardized form that included clinical predictors, pain features, and neurological symptoms. The association between the clinical predictors and pain classifications was evaluated via the Pearson Chi-Square or Fisher’s exact test (p < 0.05). Results Six clinical algorithms were generated to evaluate sensitivity and specificity, with 95% confidence intervals, for clinical predictors statistically associated with neuritis. The most conclusive clinical algorithm was: pain onset at any time during the previous 90 days, or in association with the initiation of neurological symptoms during the prior 30-day period, necessarily associated with the worsening of pain upon movement and nerve palpation, with 94% of specificity and 35% of sensitivity. Conclusion This algorithm could help physicians confirm neuritis in leprosy patients with neural pain, particularly in primary health care units with no access to neurologists or electrophysiological tests.

Neuropathic pain post-COVID-19: a case report

A 61-year-old man with no significant medical history developed fever, headache and mild shortness of breath. He tested positive for SARS-CoV-2 and self-isolated at home, not requiring hospital admission. One week after testing positive, he developed acute severe burning pain affecting his whole body, subsequently localised distally in the limbs. There was no ataxia or autonomic failure. Neurological examination was unremarkable. Electrophysiological tests were unremarkable. Skin biopsy, lumbar puncture, enhanced MRI of the brachial plexus and MRI of the neuroaxis were normal. His pain was inadequately controlled with pregabalin but improved while on a weaning regimen of steroids. This case highlights the variety of possible symptoms associated with SARS-CoV-2 infection.