Charcot–Marie–Tooth disease (CMT) is a rare hereditary neuropathy that affects peripheral nerves in the upper and lower limbs. To distinguish between the different forms of the disease, electrophysiological criteria are essential. Furthermore, identifying the genetic cause is crucial for providing accurate genetic counseling. The genetic complexity of CMT is partly explained by digenism, where mutations in two distinct genes might contribute to the disease. Two genes involved in mitochondrial dynamics, MFN2 and GDAP1, have been identified in digenic cases of CMT. This retrospective study reports MFN2/GDAP1 digenism cases identified in patients affected by CMT in our laboratory.
Methods
We conducted a retrospective analysis of 1665 patients who underwent NGS using the CMT gene panel between 2016 and 2024. These patients affected by CMT were addressed from neurology reference centers in France. The results were analyzed with bioinformatics tools, initially using the hg19 reference genome and then the hg38 version.
Results
Out of 1665 patients, 367 positive cases were identified, corresponding to a 22% molecular diagnostic rate, excluding PMP22 duplications. Among these, 15 cases involved variants in two distinct genes, resulting in a 4% digenism rate. Five cases involved MFN2/GDAP1 variants, accounting for 1.4% of the total positive results and 33% of all digenic cases.
Interpretation
The cases of digenism have a significant prevalence in CMT disease and may explain the severity of the phenotype in our patients. Multilocus variants complicate genetic counseling due to non-Mendelian inheritance. In addition, it is important to distinguish between digenism and modifier genes.
{"title":"Digenesis in Charcot–Marie–Tooth Disease: Impact of Combined Mutations in the MFN2 and GDAP1 Genes","authors":"Endrit Shumeri, Ebrahem Mandorah, Nathalie Martini, Amandine Boyer, Cécile Halbert, Angela Puma, Annabelle Chaussenot, Emilien Delmont, Karine N'guyen, Shahram Attarian, Nathalie Bonello-Palot","doi":"10.1111/jns.70044","DOIUrl":"https://doi.org/10.1111/jns.70044","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background and Aims</h3>\u0000 \u0000 <p>Charcot–Marie–Tooth disease (CMT) is a rare hereditary neuropathy that affects peripheral nerves in the upper and lower limbs. To distinguish between the different forms of the disease, electrophysiological criteria are essential. Furthermore, identifying the genetic cause is crucial for providing accurate genetic counseling. The genetic complexity of CMT is partly explained by digenism, where mutations in two distinct genes might contribute to the disease. Two genes involved in mitochondrial dynamics, <i>MFN2</i> and <i>GDAP1</i>, have been identified in digenic cases of CMT. This retrospective study reports <i>MFN2</i>/<i>GDAP1</i> digenism cases identified in patients affected by CMT in our laboratory.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We conducted a retrospective analysis of 1665 patients who underwent NGS using the CMT gene panel between 2016 and 2024. These patients affected by CMT were addressed from neurology reference centers in France. The results were analyzed with bioinformatics tools, initially using the hg19 reference genome and then the hg38 version.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Out of 1665 patients, 367 positive cases were identified, corresponding to a 22% molecular diagnostic rate, excluding <i>PMP22</i> duplications. Among these, 15 cases involved variants in two distinct genes, resulting in a 4% digenism rate. Five cases involved <i>MFN2</i>/<i>GDAP1</i> variants, accounting for 1.4% of the total positive results and 33% of all digenic cases.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Interpretation</h3>\u0000 \u0000 <p>The cases of digenism have a significant prevalence in CMT disease and may explain the severity of the phenotype in our patients. Multilocus variants complicate genetic counseling due to non-Mendelian inheritance. In addition, it is important to distinguish between digenism and modifier genes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jns.70044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144520296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luke F. O'Donnell, Victor Zhang, Roy Carganillo, Alexander M. Rossor, Matilde Laura, Mariola Skorupinska, Janet A. Gilbertson, Dorota Rowczenio, Yousuf Razvi, Julian D. Gillmore, Mary M. Reilly
Objective
Gene silencing therapy for ATTRv has revolutionised treatment. In minimally symptomatic, early neuropathic disease, skin biopsy can aid in the diagnosis of ATTRv-PN, assessing both amyloid deposition and IENFD. Our aim was to study the value of performing skin biopsies in the diagnosis of ATTRv-PN in UK patients and to assess the influence of this on accessing gene silencing treatment.
Methods
Seventy-three patients had skin biopsies performed between July 2021 and October 2023. These were stained for amyloid, typed by immunohistochemistry, and analysed for IENFD.
Results
The Thr60Ala (30%), Val122Ile (23%) and Val30Met (22%) variants represented the largest number of cases. Normal/equivocal neurophysiology was demonstrated in 78% of cases. 40% of patients had abnormal IENFD, 33% had positive amyloid and 16% had both. This allowed 33% of patients to start gene silencing therapy, 75% of whom had a preceding amyloid cardiomyopathy diagnosed.
Conclusions
Skin biopsy is a useful, minimally invasive method for diagnosing ATTRv-PN. It allowed a substantial number of patients to commence gene silencing treatment. As Thr60Ala and Val122Ile are the commonest TTR variants in the UK and patients often present with cardiomyopathy, early diagnosis of ATTRv-PN is critical for treatment decisions.
{"title":"Skin Biopsy as a Diagnostic Tool for ATTRv Amyloid Neuropathy in the UK","authors":"Luke F. O'Donnell, Victor Zhang, Roy Carganillo, Alexander M. Rossor, Matilde Laura, Mariola Skorupinska, Janet A. Gilbertson, Dorota Rowczenio, Yousuf Razvi, Julian D. Gillmore, Mary M. Reilly","doi":"10.1111/jns.70042","DOIUrl":"https://doi.org/10.1111/jns.70042","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>Gene silencing therapy for ATTRv has revolutionised treatment. In minimally symptomatic, early neuropathic disease, skin biopsy can aid in the diagnosis of ATTRv-PN, assessing both amyloid deposition and IENFD. Our aim was to study the value of performing skin biopsies in the diagnosis of ATTRv-PN in UK patients and to assess the influence of this on accessing gene silencing treatment.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Seventy-three patients had skin biopsies performed between July 2021 and October 2023. These were stained for amyloid, typed by immunohistochemistry, and analysed for IENFD.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The Thr60Ala (30%), Val122Ile (23%) and Val30Met (22%) variants represented the largest number of cases. Normal/equivocal neurophysiology was demonstrated in 78% of cases. 40% of patients had abnormal IENFD, 33% had positive amyloid and 16% had both. This allowed 33% of patients to start gene silencing therapy, 75% of whom had a preceding amyloid cardiomyopathy diagnosed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Skin biopsy is a useful, minimally invasive method for diagnosing ATTRv-PN. It allowed a substantial number of patients to commence gene silencing treatment. As Thr60Ala and Val122Ile are the commonest TTR variants in the UK and patients often present with cardiomyopathy, early diagnosis of ATTRv-PN is critical for treatment decisions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jns.70042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dennis Kool, Janneke G. J. Hoeijmakers, Catharina G. Faber, Ingemar S. J. Merkies
Background
Chronic itch, or pruritus, is a common discomfort of the skin. Chronic itch has been described as a symptom of small fiber neuropathy (SFN), a disorder affecting the small myelinated Aδ- and unmyelinated C-fibers. While prior studies report itch rates in SFN ranging from 63%–68%, a distinct pattern has not been identified.
Aim
This study aimed to describe the clinical characteristics of itch in a large cohort of SFN patients.
Methods
Between May 2016 and August 2022, 1415 patients filled out an exploratory questionnaire about characteristics of their itch symptoms. 83% were diagnosed with SFN based on the Besta criteria.
Results
Itch was reported in 66% of SFN patients, mainly experienced as tickling, prickling, and tingling sensations. Itch was most common in the evening, with 98% reporting continuous or episodic symptoms during this time. The itch was predominantly localized to the distal extremities, especially the lower legs and feet (over 50% of patients), with additional reports on the back (25%) and face (27%). Unlike the typical stocking-glove distribution seen with neuropathic pain, itch showed a slightly more proximal locus. SFN patients were more likely to report itching in the hands and feet than non-SFN patients.
Interpretation
This study reveals that itch in SFN is a frequent, heterogeneous symptom that may differ from neuropathic pain in its distribution. Itch, particularly in the hands and feet, may provide diagnostic guidance and suggest SFN as a potential diagnosis. This finding warrants further research on itch mechanisms and its diagnostic value in SFN.
{"title":"Where Does It All Itch? Exploring the Characteristics of Pruritus in Small Fiber Neuropathy","authors":"Dennis Kool, Janneke G. J. Hoeijmakers, Catharina G. Faber, Ingemar S. J. Merkies","doi":"10.1111/jns.70041","DOIUrl":"https://doi.org/10.1111/jns.70041","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Chronic itch, or pruritus, is a common discomfort of the skin. Chronic itch has been described as a symptom of small fiber neuropathy (SFN), a disorder affecting the small myelinated Aδ- and unmyelinated C-fibers. While prior studies report itch rates in SFN ranging from 63%–68%, a distinct pattern has not been identified.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aim</h3>\u0000 \u0000 <p>This study aimed to describe the clinical characteristics of itch in a large cohort of SFN patients.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Between May 2016 and August 2022, 1415 patients filled out an exploratory questionnaire about characteristics of their itch symptoms. 83% were diagnosed with SFN based on the Besta criteria.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Itch was reported in 66% of SFN patients, mainly experienced as tickling, prickling, and tingling sensations. Itch was most common in the evening, with 98% reporting continuous or episodic symptoms during this time. The itch was predominantly localized to the distal extremities, especially the lower legs and feet (over 50% of patients), with additional reports on the back (25%) and face (27%). Unlike the typical stocking-glove distribution seen with neuropathic pain, itch showed a slightly more proximal locus. SFN patients were more likely to report itching in the hands and feet than non-SFN patients.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Interpretation</h3>\u0000 \u0000 <p>This study reveals that itch in SFN is a frequent, heterogeneous symptom that may differ from neuropathic pain in its distribution. Itch, particularly in the hands and feet, may provide diagnostic guidance and suggest SFN as a potential diagnosis. This finding warrants further research on itch mechanisms and its diagnostic value in SFN.</p>\u0000 </section>\u0000 </div>","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jns.70041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144473191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Israt Jahan, Rasel Ahmed, Jigishu Ahmed, Nure Alam Afsar, Pritha Promita Biswas, Sarah Khurshid, Quazi Deen Mohammad, Hubert P. Endtz, Ruth Huizinga, Bart C. Jacobs, Zhahirul Islam
Background and Aims
Intravenous immunoglobulin (IVIg) is the primary treatment for Guillain-Barré syndrome (GBS), yet its immunological mechanisms underlying variable clinical outcomes remain unclear. This study investigated the immunomodulatory effect of IVIg on regulatory T cells (Tregs), cytokines, and their association with treatment response and clinical outcomes.
Methods
In this prospective case-controlled study, 57 GBS patients and 57 age- and sex-matched healthy controls (HCs) were investigated. CD4+CD25+FoxP3+ Treg percentages, cytokine production (IL-10, TNF-α, IFN-γ, and IL-12), and serum C3 levels were measured using flow cytometry, Luminex assay, and turbidimetric methods, respectively. Treatment response was defined as ≥ 1-point GBS-disability score improvement during evaluation.
Results
GBS patients exhibited lower CD4+CD25+FoxP3+ Tregs frequencies compared to HCs (p = 0.006), which were inversely associated with serum C3 levels (p = 0.003) during the acute phase. At 4 weeks post-onset, patients with normal C3 levels (90–180 mg/dL) exhibited higher Treg frequencies (p = 0.005) compared to acute GBS, whereas patients with persistently elevated C3 levels showed reduced Treg percentage (p = 0.009). Among I VIg-treated patients, Tregs significantly increased at 2 and 4 weeks post-treatment, alongside significantly higher IL-10 and lower TNF-α, IFN-γ, and IL-12 levels at 4 weeks. However, patients with supportive care showed no such changes in Tregs and cytokine levels. Furthermore, Tregs elevated significantly in patients responsive to IVIg at 2 and 4 weeks (p < 0.05), but not in non-responsive or supportive care patients.
Interpretation
IVIg treatment modulates immune dysregulation in GBS by expanding CD4+CD25+FoxP3+ Tregs and altering cytokines and serum C3 levels, which are associated with clinical improvement. These findings indicate Tregs as potential biomarkers for monitoring initial clinical response to IVIg in GBS.
{"title":"Intravenous Immunoglobulin Elevates Regulatory T Cells in Guillain-Barré Syndrome: A Potential Biomarker of Therapeutic Response","authors":"Israt Jahan, Rasel Ahmed, Jigishu Ahmed, Nure Alam Afsar, Pritha Promita Biswas, Sarah Khurshid, Quazi Deen Mohammad, Hubert P. Endtz, Ruth Huizinga, Bart C. Jacobs, Zhahirul Islam","doi":"10.1111/jns.70039","DOIUrl":"https://doi.org/10.1111/jns.70039","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background and Aims</h3>\u0000 \u0000 <p>Intravenous immunoglobulin (IVIg) is the primary treatment for Guillain-Barré syndrome (GBS), yet its immunological mechanisms underlying variable clinical outcomes remain unclear. This study investigated the immunomodulatory effect of IVIg on regulatory T cells (Tregs), cytokines, and their association with treatment response and clinical outcomes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In this prospective case-controlled study, 57 GBS patients and 57 age- and sex-matched healthy controls (HCs) were investigated. CD4<sup>+</sup>CD25<sup>+</sup>FoxP3<sup>+</sup> Treg percentages, cytokine production (IL-10, TNF-α, IFN-γ, and IL-12), and serum C3 levels were measured using flow cytometry, Luminex assay, and turbidimetric methods, respectively. Treatment response was defined as ≥ 1-point GBS-disability score improvement during evaluation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>GBS patients exhibited lower CD4<sup>+</sup>CD25<sup>+</sup>FoxP3<sup>+</sup> Tregs frequencies compared to HCs (<i>p</i> = 0.006), which were inversely associated with serum C3 levels (<i>p</i> = 0.003) during the acute phase. At 4 weeks post-onset, patients with normal C3 levels (90–180 mg/dL) exhibited higher Treg frequencies (<i>p</i> = 0.005) compared to acute GBS, whereas patients with persistently elevated C3 levels showed reduced Treg percentage (<i>p</i> = 0.009). Among I VIg-treated patients, Tregs significantly increased at 2 and 4 weeks post-treatment, alongside significantly higher IL-10 and lower TNF-α, IFN-γ, and IL-12 levels at 4 weeks. However, patients with supportive care showed no such changes in Tregs and cytokine levels. Furthermore, Tregs elevated significantly in patients responsive to IVIg at 2 and 4 weeks (<i>p</i> < 0.05), but not in non-responsive or supportive care patients.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Interpretation</h3>\u0000 \u0000 <p>IVIg treatment modulates immune dysregulation in GBS by expanding CD4<sup>+</sup>CD25<sup>+</sup>FoxP3<sup>+</sup> Tregs and altering cytokines and serum C3 levels, which are associated with clinical improvement. These findings indicate Tregs as potential biomarkers for monitoring initial clinical response to IVIg in GBS.</p>\u0000 </section>\u0000 </div>","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144473189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anthara Gnanakumar, Rana Aljaberi, Dawn A. Laney, Christian Martin, Stephanie R. Keller, Suhag H. Parikh, Sumit Verma
Introduction
Krabbe disease, or globoid cell leukodystrophy, is a rare autosomal recessive neurodegenerative disorder characterized by deficient activity of the lysosomal enzyme galactosylceramidase (GALC). This deficiency leads to the toxic accumulation of psychosine, resulting in progressive demyelination and neuronal death. The clinical manifestations of Krabbe disease progress through different stages, starting with irritability, stiffness, and feeding difficulties, followed by myoclonic-like jerks in the upper and lower extremities, hypertonicity, and eventually severe hypotonia and lack of movement.
Methods
This case report features two newborn screening patients with (NBS)-positive Krabbe disease who underwent electrodiagnostic (EDX) testing and hematopoietic stem cell transplantation (HSCT) soon after birth.
Results
The EDX results indicated severe sensory-motor polyneuropathy of mixed demyelinating and axonal types. Biochemical analyses confirmed significantly reduced GALC enzyme activity and elevated psychosine levels in both cases. Genetic testing identified pathogenic variants, including compound heterozygous deletions and mutations within the GALC gene. At 6-month follow-up post-HSCT, one patient showed age-appropriate milestones and improvement in motor amplitudes on repeat nerve conduction studies.
Discussion
EDX testing is helpful in assessing NBS-positive Krabbe disease before confirmatory testing results become available. In conjunction with genetic confirmation and GALC enzyme levels, EDX test results were useful to counsel families that their seemingly normal newborn has severe disease and facilitated discussion toward timely treatment with HSCT. We suggest that EDX be included in the initial and follow-up evaluation of patients with Krabbe disease undergoing HSCT.
{"title":"Peripheral Neuropathy as an Early Marker in Newborn-Screened Krabbe Disease: The Value of Pre-Confirmatory Neurophysiological Testing","authors":"Anthara Gnanakumar, Rana Aljaberi, Dawn A. Laney, Christian Martin, Stephanie R. Keller, Suhag H. Parikh, Sumit Verma","doi":"10.1111/jns.70040","DOIUrl":"https://doi.org/10.1111/jns.70040","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>Krabbe disease, or globoid cell leukodystrophy, is a rare autosomal recessive neurodegenerative disorder characterized by deficient activity of the lysosomal enzyme galactosylceramidase (GALC). This deficiency leads to the toxic accumulation of psychosine, resulting in progressive demyelination and neuronal death. The clinical manifestations of Krabbe disease progress through different stages, starting with irritability, stiffness, and feeding difficulties, followed by myoclonic-like jerks in the upper and lower extremities, hypertonicity, and eventually severe hypotonia and lack of movement.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This case report features two newborn screening patients with (NBS)-positive Krabbe disease who underwent electrodiagnostic (EDX) testing and hematopoietic stem cell transplantation (HSCT) soon after birth.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The EDX results indicated severe sensory-motor polyneuropathy of mixed demyelinating and axonal types. Biochemical analyses confirmed significantly reduced GALC enzyme activity and elevated psychosine levels in both cases. Genetic testing identified pathogenic variants, including compound heterozygous deletions and mutations within the <i>GALC</i> gene. At 6-month follow-up post-HSCT, one patient showed age-appropriate milestones and improvement in motor amplitudes on repeat nerve conduction studies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>EDX testing is helpful in assessing NBS-positive Krabbe disease before confirmatory testing results become available. In conjunction with genetic confirmation and GALC enzyme levels, EDX test results were useful to counsel families that their seemingly normal newborn has severe disease and facilitated discussion toward timely treatment with HSCT. We suggest that EDX be included in the initial and follow-up evaluation of patients with Krabbe disease undergoing HSCT.</p>\u0000 </section>\u0000 </div>","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144473190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amanda S. Mondschein, Mathieu R. DiPersio, Julia Zajaceskowski, Hasitha Nimmagadda, Jenica Acheta, Abigail E. Salinero, Sarah Haslam, Elwenn Poitelon, Sophia Elston, Ethan McFarland, Brianna Beck, Kristen L. Zuloaga, Amy E. Rumora, Yannick Poitelon, Sophie Belin
Background and Aims
Diabetic peripheral neuropathy (DPN) is a debilitating complication of diabetes, with Schwann cell dysfunction increasingly implicated in disease progression. This study aimed to investigate how high-fat diet (HFD)-induced metabolic syndrome (MetS) affects Schwann cells and peripheral nerve function in male and female mice.
Methods
Male and female C57BL/6J mice were fed a standard diet (SD) or HFD for 33 weeks. Metabolic phenotyping included body weight, fasting blood glucose, and glucose tolerance tests. Peripheral nerve function was assessed via motor and sensory nerve conduction velocities (NCVs), behavioral tests (grip strength, thermal preference, Von Frey), intraepidermal nerve fiber density (IENFD) counts, and sciatic nerve morphological analysis. Myelin protein expression was analyzed by Western blotting and immunohistochemistry.
Results
Both sexes developed MetS features, though males exhibited more pronounced hyperglycemia. HFD mice showed thermal hyperalgesia, reduced IENFD, and slowed NCVs, consistent with DPN. Morphological studies revealed sex-specific myelin thinning and structural abnormalities without significant axonal degeneration. In males, HFD was associated with reduced muscular strength, a decrease in myelin thickness of small-caliber axons, and an increase in the Peripheral Myelin Protein 2 (PMP2), a fatty acid chaperone. In females, although HFD led to myelin decompaction, it was not associated with muscle strength deficits or changes in myelin composition.
Interpretation
HFD-induced MetS impairs Schwann cell function and peripheral nerve health in a sex-dependent manner. Myelin defects and PMP2 upregulation suggest that altered lipid metabolism contributes to neuropathy progression. These findings highlight Schwann cells as key mediators of MetS-associated peripheral neuropathy and underscore the need for sex-specific therapeutic strategies.
{"title":"High-Fat Diet Disrupt Nerve Function by Targeting Schwann Cells","authors":"Amanda S. Mondschein, Mathieu R. DiPersio, Julia Zajaceskowski, Hasitha Nimmagadda, Jenica Acheta, Abigail E. Salinero, Sarah Haslam, Elwenn Poitelon, Sophia Elston, Ethan McFarland, Brianna Beck, Kristen L. Zuloaga, Amy E. Rumora, Yannick Poitelon, Sophie Belin","doi":"10.1111/jns.70036","DOIUrl":"https://doi.org/10.1111/jns.70036","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background and Aims</h3>\u0000 \u0000 <p>Diabetic peripheral neuropathy (DPN) is a debilitating complication of diabetes, with Schwann cell dysfunction increasingly implicated in disease progression. This study aimed to investigate how high-fat diet (HFD)-induced metabolic syndrome (MetS) affects Schwann cells and peripheral nerve function in male and female mice.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Male and female C57BL/6J mice were fed a standard diet (SD) or HFD for 33 weeks. Metabolic phenotyping included body weight, fasting blood glucose, and glucose tolerance tests. Peripheral nerve function was assessed via motor and sensory nerve conduction velocities (NCVs), behavioral tests (grip strength, thermal preference, Von Frey), intraepidermal nerve fiber density (IENFD) counts, and sciatic nerve morphological analysis. Myelin protein expression was analyzed by Western blotting and immunohistochemistry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Both sexes developed MetS features, though males exhibited more pronounced hyperglycemia. HFD mice showed thermal hyperalgesia, reduced IENFD, and slowed NCVs, consistent with DPN. Morphological studies revealed sex-specific myelin thinning and structural abnormalities without significant axonal degeneration. In males, HFD was associated with reduced muscular strength, a decrease in myelin thickness of small-caliber axons, and an increase in the Peripheral Myelin Protein 2 (PMP2), a fatty acid chaperone. In females, although HFD led to myelin decompaction, it was not associated with muscle strength deficits or changes in myelin composition.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Interpretation</h3>\u0000 \u0000 <p>HFD-induced MetS impairs Schwann cell function and peripheral nerve health in a sex-dependent manner. Myelin defects and PMP2 upregulation suggest that altered lipid metabolism contributes to neuropathy progression. These findings highlight Schwann cells as key mediators of MetS-associated peripheral neuropathy and underscore the need for sex-specific therapeutic strategies.</p>\u0000 </section>\u0000 </div>","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 2","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144292700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Variability in Conduction Block Definitions Affects the Sensitivity of Diagnostic Criteria for Multifocal Motor Neuropathy","authors":"Lucas Immich Gonçalves, Vera Bril","doi":"10.1111/jns.70034","DOIUrl":"https://doi.org/10.1111/jns.70034","url":null,"abstract":"","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 2","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yusuf A. Rajabally, Chinar Osman, James K. L. Holt
{"title":"Is Conduction Block Everything in Multifocal Motor Neuropathy?","authors":"Yusuf A. Rajabally, Chinar Osman, James K. L. Holt","doi":"10.1111/jns.70035","DOIUrl":"https://doi.org/10.1111/jns.70035","url":null,"abstract":"","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 2","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Abstract","authors":"","doi":"10.1111/jns.70028","DOIUrl":"https://doi.org/10.1111/jns.70028","url":null,"abstract":"","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 S2","pages":"S3-S49"},"PeriodicalIF":3.9,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144237285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Caroline Kramarz, Marion Masingue, Françoise Bouhour, Christophe Vial, Philippe Latour, Christophe Vandendries, Thierry Maisonobe, Jan Coebergh, Julian Blake, Mary M. Reilly, Tanya Stojkovic, Alexander M. Rossor
Background and Aims
Peripheral neuropathy may present with a variety of phenotypes depending on the pattern of weakness and sensory loss, the neurophysiological characteristics (axonal or demyelinating) and additional features such as involvement of the autonomic nervous system or the cranial nerves. The most common phenotype is a symmetrical length-dependent sensory and motor neuropathy. Other phenotypes include non-length-dependent forms such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) or a sensory neuronopathy or ganglionopathy. Asymmetric forms of neuropathy are mostly represented by mononeuritis multiplex and Lewis-Sumner syndrome or focal CIDP. Unilateral weakness or sensory loss respecting the midline is mainly due to pathology in the central nervous system and is unusual in peripheral neuropathy.
Methods
We evaluated the clinical and genetic features of three unrelated individuals with a peripheral neuropathy affecting one side of the body.
Results
We describe three unrelated patients (two female and one male) with a slowly progressive peripheral neuropathy restricted to one side of the body. Each case is marked by onset in early childhood with the absence of a family history or a structural lesion of the central nervous system. Neurophysiology demonstrated an axonal type of neuropathy in two cases and conduction slowing supportive of a demyelinating neuropathy type in one. Genetic testing was performed in the three cases, specifically looking for variants in genes associated with Charcot-Marie-Tooth disease (CMT) but none were identified in DNA extracted from blood.
Interpretation
A unilateral, slowly progressive peripheral neuropathy is a rare phenomenon, and we propose the cause of this unusual phenotype to be due to a mosaic or chimeric form of Charcot-Marie-Tooth disease (CMT).
{"title":"A Case Series of Unilateral Peripheral Neuropathy","authors":"Caroline Kramarz, Marion Masingue, Françoise Bouhour, Christophe Vial, Philippe Latour, Christophe Vandendries, Thierry Maisonobe, Jan Coebergh, Julian Blake, Mary M. Reilly, Tanya Stojkovic, Alexander M. Rossor","doi":"10.1111/jns.70033","DOIUrl":"https://doi.org/10.1111/jns.70033","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background and Aims</h3>\u0000 \u0000 <p>Peripheral neuropathy may present with a variety of phenotypes depending on the pattern of weakness and sensory loss, the neurophysiological characteristics (axonal or demyelinating) and additional features such as involvement of the autonomic nervous system or the cranial nerves. The most common phenotype is a symmetrical length-dependent sensory and motor neuropathy. Other phenotypes include non-length-dependent forms such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) or a sensory neuronopathy or ganglionopathy. Asymmetric forms of neuropathy are mostly represented by mononeuritis multiplex and Lewis-Sumner syndrome or focal CIDP. Unilateral weakness or sensory loss respecting the midline is mainly due to pathology in the central nervous system and is unusual in peripheral neuropathy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We evaluated the clinical and genetic features of three unrelated individuals with a peripheral neuropathy affecting one side of the body.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We describe three unrelated patients (two female and one male) with a slowly progressive peripheral neuropathy restricted to one side of the body. Each case is marked by onset in early childhood with the absence of a family history or a structural lesion of the central nervous system. Neurophysiology demonstrated an axonal type of neuropathy in two cases and conduction slowing supportive of a demyelinating neuropathy type in one. Genetic testing was performed in the three cases, specifically looking for variants in genes associated with Charcot-Marie-Tooth disease (CMT) but none were identified in DNA extracted from blood.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Interpretation</h3>\u0000 \u0000 <p>A unilateral, slowly progressive peripheral neuropathy is a rare phenomenon, and we propose the cause of this unusual phenotype to be due to a mosaic or chimeric form of Charcot-Marie-Tooth disease (CMT).</p>\u0000 </section>\u0000 </div>","PeriodicalId":17451,"journal":{"name":"Journal of the Peripheral Nervous System","volume":"30 2","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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