Staff, Nathan P.

AbstractIntroduction/AimsFemoral neuropathies can cause severe, prolonged debility, yet there have been few clinical and electrodiagnostic (EDx) studies addressing this condition. The aim of this study was to better understand the etiologies, EDx features, and clinical course of femoral neuropathy.MethodsWe identified patients evaluated at Mayo Clinic Rochester between January 1, 1999 and July 31, 2019, with possible new femoral neuropathy ascertained via International Classification of Diseases‐versions 9 and 10 diagnosis codes presenting within 6 months of symptom onset.ResultsA retrospective review of 1084 records was performed and we ultimately identified 159 patients with isolated femoral neuropathy for inclusion. The most common femoral neuropathy etiologies were compressive (40%), perioperative stretch (35%), and inflammatory (6%). Presenting symptoms included weakness (96%), sensory loss (73%), and pain (53%). Presenting motor physical exam findings demonstrated moderate weakness (34%) or no activation (25%) of knee extension and mild (32%) or moderate (35%) weakness of hip flexion. Seventy‐two percent of patients underwent EDx testing, including 22 with femoral motor nerve conduction studies. Treatment often involved physical therapy (89%) and was otherwise etiology‐specific. In patients with follow‐up data available (n = 154), 83% had subjective clinical improvement at follow‐up with a mean time to initial improvement of 3.3 months and mean time to recovery at final follow‐up of 14.8 months. Only 48% of patients had nearly complete or complete recovery.DiscussionIn our cohort, the most common etiologies of femoral neuropathy were compression or perioperative stretch with high initial morbidity. Although motor recovery is common, improvement is often prolonged and incomplete.

The chemotherapeutic agent paclitaxel causes peripheral neuropathy, a dose-limiting side effect, in up to 68% of cancer patients. In this study, we investigated the impact of paclitaxel therapy on the skin of breast cancer patients with chemotherapy-induced peripheral neuropathy (CIPN), building upon previous findings in zebrafish and rodents. Comprehensive assessments, including neurological examinations and quality of life questionnaires, were conducted, followed by intraepidermal nerve fiber (IENF) density evaluations using skin punch biopsies. Additionally, RNA sequencing, immunostaining for Matrix-Metalloproteinase 13 (MMP-13), and transmission electron microscopy provided insights into molecular and ultrastructural changes in this skin. The results showed no significant difference in IENF density between the control and CIPN patients despite the presence of patient-reported CIPN symptoms. Nevertheless, the RNA sequencing and immunostaining on the skin revealed significantly upregulated MMP-13, which is known to play a key role in CIPN caused by paclitaxel therapy. Additionally, various genes involved in the regulation of the extracellular matrix, microtubules, cell cycle, and nervous system were significantly and differentially expressed. An ultrastructural examination of the skin showed changes in collagen and basement membrane structures. These findings highlight the presence of CIPN in the absence of IENF density changes and support the role of skin remodeling as a major contributor to CIPN.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with a median survival of about 3 years. An ALS multidisciplinary team can provide primary palliative care and improve outcomes and quality of life for patients. Feeding tube insertion may be considered for patients with significant weight loss, or respiratory insufficiency. While radiologically inserted gastrostomy (RIG) tube placement may be an option, further studies are required to determine its best timing and appropriateness. This study’s objectives were to evaluate the feasibility and outcomes of RIG tube placement in ALS patients over a 90-day follow-up period through the assessment and primary palliative care provided by the multidisciplinary team. This retrospective study reviewed the placement of 16 or 18 French RIG-tube without intubation or endoscopy for 36 ALS patients at a single center between April 2019 and December 2021. Measures included ALS Functional Rating Scale-Revised (ALSFRS-R) scores to determine the ALS stage. Demographic, clinical, procedural, and follow-up data were reviewed. Results showed that the RIG tube placement had a low rate of minor adverse events (11%) and no major procedure-related adverse events. The mean ALSFRS-R score at the time of procedure in subjects who died within 90 days was lower than of those alive beyond 90 days ( P = .04). This study found that RIG-tube placement is a safe and effective way to manage dysphagia in ALS patients and highlights the importance of educating members of the multidisciplinary clinic in palliative care principles to determine the appropriateness of RIG tube placement.

Abstract Objective To identify potential diagnostic and prognostic biomarkers for clinical management and clinical trials in amyotrophic lateral sclerosis. Methods We analysed proteomics data of ALS patient‐induced pluripotent stem cell‐derived motor neurons available through the AnswerALS consortium. After stratifying patients using clinical ALSFRS‐R and ALS‐CBS scales, we identified differentially expressed proteins indicative of ALS disease severity and progression rate as candidate ALS‐related and prognostic biomarkers. Pathway analysis for identified proteins was performed using STITCH. Protein sets were correlated with the effects of drugs using the Connectivity Map tool to identify compounds likely to affect similar pathways. RNAi screening was performed in a Drosophila TDP‐43 ALS model to validate pathological relevance. A statistical classification machine learning model was constructed using ridge regression that uses proteomics data to differentiate ALS patients from controls. Results We identified 76, 21, 71 and 1 candidate ALS‐related biomarkers and 22, 41, 27 and 64 candidate prognostic biomarkers from patients stratified by ALSFRS‐R baseline, ALSFRS‐R progression slope, ALS‐CBS baseline and ALS‐CBS progression slope, respectively. Nineteen proteins enhanced or suppressed pathogenic eye phenotypes in the ALS fly model. Nutraceuticals, dopamine pathway modulators, statins, anti‐inflammatories and antimicrobials were predicted starting points for drug repurposing using the connectivity map tool. Ten diagnostic biomarker proteins were predicted by machine learning to identify ALS patients with high accuracy and sensitivity. Interpretation This study showcases the powerful approach of iPSC‐motor neuron proteomics combined with machine learning and biological confirmation in the prediction of novel mechanisms and diagnostic and predictive biomarkers in ALS.

AbstractIntroduction/AimsAmyotrophic lateral sclerosis (ALS) is a progressive, fatal, neurodegenerative disorder of motor neurons in which the cause is mostly unknown. Early identification of genetic ALS cases, of which C9ORF72 (C9ALS) is the most frequent, can have important implications for evaluation, prognosis, and therapeutics. Here, we aimed to characterize the clinical and electrophysiological hallmarks of C9ALS and investigate differences from C9ORF72 negative ALS (non‐C9ALS).MethodsWe retrospectively reviewed clinical and electrodiagnostic (EDX) data for all genetically confirmed C9ALS cases seen between 1/1/2012 and 10/1/2020 who met Gold Coast criteria and compared them 1:1 with non‐C9ALS patients within the same time frame.ResultsA total of 99 C9ALS and 99 non‐C9ALS cases were identified. Compared to non‐C9ALS, C9ALS demonstrated higher prevalence in women, lesser racial variability, stronger family history of ALS, and higher frequency of upper motor neuron signs. EDX testing of C9ALS showed higher median sensory nerve and lower fibular compound muscle action potential amplitudes.DiscussionAlthough the differences between C9ALS and non‐C9ALS reached statistical significance in certain nerve conduction parameters, they were not sufficient to discriminate between groups on a case‐by‐case basis. Genetic testing is required to identify C9ALS patients.

Introduction As the pandemic continues with new variants emerging, faculty and students require support with education's rapid shift to the virtual space. The Mayo Clinic Center for Clinical and Translational Science curriculum team works closely with faculty to support a smooth transition to offering graduate courses in a virtual learning environment. The aim of the present project was to explore faculty and student perceptions of these remote learning strategies to gain an understanding of the innovations required to improve future educational offerings. Methods All faculty and learners involved in nine Clinical and Translational Science courses in spring 2020 were invited to participate in a web-based questionnaire. Quantitative analysis was performed on closed-ended items, including 5-point Likert-scale questions used to assess the range of views. Qualitative free-text responses were independently analyzed for repetitive themes and summarized. Additionally, comparisons of faculty and course evaluations and student grade point averages (GPAs) from the in-person courses and their subsequent virtual course offerings were considered. Results Survey results indicated several positive impacts with moving courses into the virtual environment, including increased accessibility as well as more student-centered education. Learners joining from sites outside of the originating campus were especially grateful for the virtual classroom because they felt newly integrated within classes. Faculty and course evaluations, as well as student GPAs, remained consistent. Conclusion New COVID-19 variants continue to shift education online, and innovative ideas are required to further improve future virtual course offerings. Increased engagement is warranted, both from faculty to incorporate activities designed specifically for a virtual classroom, and from students to increase participation by activating their microphones and webcams. Greater opportunities for global involvement and connectedness arise. Finally, this project advocates for adequate eLearning staffing to support quality online education as the need for pedagogical and technical provision continues.