scholarly journals Intraepidermal Nerve Fibers Are Indicators of Small-Fiber Neuropathy in Both Diabetic and Nondiabetic Patients

Diabetes Care ◽  
2004 ◽  
Vol 27 (8) ◽  
pp. 1974-1979 ◽  
Author(s):  
G. L. Pittenger ◽  
M. Ray ◽  
N. I. Burcus ◽  
P. McNulty ◽  
B. Basta ◽  
...  
Keyword(s):  
Nerve Fibers ◽  
Small Fiber Neuropathy ◽  
Small Fiber

scholarly journals Ca2+ toxicity due to reverse Na+/Ca2+ exchange contributes to degeneration of neurites of DRG neurons induced by a neuropathy-associated Nav1.7 mutation

2015 ◽  
Vol 114 (3) ◽  
pp. 1554-1564 ◽  
Author(s):  
M. Estacion ◽  
B. P. S Vohra ◽  
S. Liu ◽  
J. Hoeijmakers ◽  
C. G. Faber ◽  
...  
Keyword(s):  
Nerve Fibers ◽  
Small Fiber Neuropathy ◽  
Missense Mutations ◽  
Sodium Calcium Exchanger ◽  
Drg Neurons ◽  
Persistent Currents ◽  
Burning Pain ◽  
Reverse Mode ◽  
Small Fiber ◽  
High K

Gain-of-function missense mutations in voltage-gated sodium channel Nav1.7 have been linked to small-fiber neuropathy, which is characterized by burning pain, dysautonomia and a loss of intraepidermal nerve fibers. However, the mechanistic cascades linking Nav1.7 mutations to axonal degeneration are incompletely understood. The G856D mutation in Nav1.7 produces robust changes in channel biophysical properties, including hyperpolarized activation, depolarized inactivation, and enhanced ramp and persistent currents, which contribute to the hyperexcitability exhibited by neurons containing Nav1.8. We report here that cell bodies and neurites of dorsal root ganglion (DRG) neurons transfected with G856D display increased levels of intracellular Na+ concentration ([Na+]) and intracellular [Ca2+] following stimulation with high [K+] compared with wild-type (WT) Nav1.7-expressing neurons. Blockade of reverse mode of the sodium/calcium exchanger (NCX) or of sodium channels attenuates [Ca2+] transients evoked by high [K+] in G856D-expressing DRG cell bodies and neurites. We also show that treatment of WT or G856D-expressing neurites with high [K+] or 2-deoxyglucose (2-DG) does not elicit degeneration of these neurites, but that high [K+] and 2-DG in combination evokes degeneration of G856D neurites but not WT neurites. Our results also demonstrate that 0 Ca2+ or blockade of reverse mode of NCX protects G856D-expressing neurites from degeneration when exposed to high [K+] and 2-DG. These results point to [Na+] overload in DRG neurons expressing mutant G856D Nav1.7, which triggers reverse mode of NCX and contributes to Ca2+ toxicity, and suggest subtype-specific blockade of Nav1.7 or inhibition of reverse NCX as strategies that might slow or prevent axon degeneration in small-fiber neuropathy.

A quantitative method for the assessment of intraepidermal nerve fibers in small–fiber neuropathy

2005 ◽  
Vol 252 (7) ◽  
pp. 789-794 ◽  
Author(s):  
M. Koskinen ◽  
A. Hietaharju ◽  
M. Kyläniemi ◽  
J. Peltola ◽  
I. Rantala ◽  
...  
Keyword(s):  
Quantitative Method ◽  
Nerve Fibers ◽  
Small Fiber Neuropathy ◽  
Small Fiber

Successful Use of Flupirtine in Refractory Neuropathic Pain Due to Small Fiber Neuropathy

2012 ◽  
Vol 30 (1) ◽  
pp. 91-93 ◽  
Author(s):  
Seema Mishra ◽  
Prakash Choudhary ◽  
Saurabh Joshi ◽  
Sushma Bhatnagar
Keyword(s):  
Neuropathic Pain ◽  
Small Diameter ◽  
Nerve Fibers ◽  
Small Fiber Neuropathy ◽  
First Line ◽  
Small Fiber ◽  
Peripheral Pain ◽  
Multiple Drugs

Small fiber neuropathy typically involves the small diameter nerve fibers, is usually idiopathic, and presents with peripheral pain. It can be excruciatingly painful at times despite the best of treatments. We present the case of a 22-year-old postoperative case of right frontoparietal oligodendroglioma who received multiple drugs for his severe neuropathic pain without significant relief. However, the pain almost completely subsided once flupirtine was added and substituted for some of the currently recommended first-line drugs.

scholarly journals Intraepidermal Nerve Fiber Density as Measured by Skin Punch Biopsy as a Marker for Small Fiber Neuropathy: Application in Patients with Fibromyalgia

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 536
Author(s):  
Mary A. Kelley ◽  
Kevin V. Hackshaw
Keyword(s):  
Punch Biopsy ◽  
Nerve Fibers ◽  
Small Fiber Neuropathy ◽  
Confocal Imaging ◽  
Fiber Density ◽  
Use Of Resources ◽  
Small Fiber ◽  
Intraepidermal Nerve Fiber Density ◽  
Skin Punch Biopsy ◽  
Quantitative Sensory Tests

Small fiber neuropathy (SFN) is a type of peripheral neuropathy that occurs from damage to the small A-delta and C nerve fibers that results in the clinical condition known as SFN. This pathology may be the result of metabolic, toxic, immune-mediated, and/or genetic factors. Small fiber symptoms can be variable and inconsistent and therefore require an objective biomarker confirmation. Small fiber dysfunction is not typically captured by diagnostic tests for large-fiber neuropathy (nerve conduction and electromyographic study). Therefore, skin biopsies stained with PGP 9.5 are the universally recommended objective test for SFN, with quantitative sensory tests, autonomic function testing, and corneal confocal imaging as secondary or adjunctive choices. Fibromyalgia (FM) is a heterogenous syndrome that has many symptoms that overlap with those found in SFN. A growing body of research has shown approximately 40–60% of patients carrying a diagnosis of FM have evidence of SFN on skin punch biopsy. There is currently no clearly defined phenotype in FM at this time to suggest whom may or may not have SFN, though research suggests it may correlate with severe cases. The skin punch biopsy provides an objective tool for use in quantifying small fiber pathology in FM. Skin punch biopsy may also be repeated for surveillance of the disease as well as measuring response to treatments. Evaluation of SFN in FM allows for better classification of FM and guidance for patient care as well as validation for their symptoms, leading to better use of resources and outcomes.

scholarly journals Small Fiber Neuropathy in Pulmonary Sarcoidosis and Tuberculosis: Clinical and Histological Correlates

2020 ◽  
Author(s):  
Anna Starshinova ◽  
Natalia Basantsova ◽  
Yulia Zinchenko ◽  
Valeria Shapkina ◽  
Anna Malkova ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Neurological Complication ◽  
Unknown Origin ◽  
Pulmonary Sarcoidosis ◽  
Nerve Fibers ◽  
Small Fiber Neuropathy ◽  
Fiber Density ◽  
Tuberculosis Patients ◽  
Small Fiber ◽  
Intraepidermal Nerve Fiber Density

Abstract Sarcoidosis (SC) is the granulomatous disease of an unknown origin, where the differential diagnosis with tuberculosis (TB) is challenging and vital for patients’ prognosis. The common neurological complication in SC is a small fiber neuropathy (SFN), that is considered to be the result of the chronic inflammation, and remains significantly understudied. There is no reliable data, whether such complication is observed in TB patients, where the systemic inflammation is also described. Aim: To identify the clinical and histological correlates of the small fiber neuropathy in sarcoidosis and tuberculosis patients.Materials and methods. A study was performed in 2018 – 2019 years and included 71 patients with pulmonary sarcoidosis (n=25), pulmonary tuberculosis (n=21), and healthy subjects (n=25). For the clinical verification of the SFN, the “Small fiber neuropathy screening list” (SFN-SL) was used. A punch biopsy of the skin was performed followed by the enzyme immunoassay analysis with PGP 9.5 antibodies.Results of the study: Up to 60% of sarcoidosis patients and 19% tuberculosis patients report the presence of at least one complaint, which may be associated with SFN. The most frequent complaints included dysfunctions of the cardiovascular, musculoskeletal system and gastrointestinal tract. A negative, statistically significant correlation between the intraepidermal nerve fiber density (IEND) and SFN-SL score was revealed in both groups (Spearman coefficient, r = -0.3508, p = 0.0102, and r = -0.7382, p = 0.0064, respectively). Wherein, the density of small nerve fibers in the patients with pulmonary sarcoidosis was lower, compared to the patients with tuberculosis (Mann-Whitney test, p = 0.0047). Conclusion: In patients with pulmonary sarcoidosis, small fiber neuropathy may develop as a result of systemic immune-mediated inflammation. The most common symptoms of this complication were dysautonomia and mild sensory dysfunction. Wherein, in tuberculosis patients clinical and histological symptoms of the small fiber neuropathy were subsequently less prominent, which may represent the difference between the autoimmune and bacterial inflammation. The validated questionnaires and histologic verification of the diagnosis help to establish the severity of neuropathy of small fibers, to determine the prognosis, to plan the treatment strategн, and also may allude the possibility for the additional criteria of differential diagnosis between two diseases.

scholarly journals Topical Phenytoin Cream Reduces Burning Pain Due to Small Fiber Neuropathy in Sarcoidosis

2017 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Sleep Disturbances ◽  
Nerve Fibers ◽  
Small Fiber Neuropathy ◽  
Patient Case ◽  
Burning Pain ◽  
Small Fiber ◽  
Minute Period ◽  
Single Blind ◽  
Placebo Cream ◽  
Small Nerve

We present a patient case of burning pain and sleep disturbances due to small fiber neuropathy (SFN) in sarcoidosis, treated successfully by topically applied phenytoin 10% cream. Using a single blind, placebo-controlled response test, the patient identified that within a 10 minute period phenytoin 10% cream provided a pain reduction of 50%, while placebo cream did not reduce pain at all. Subsequently, the patient was prescribed phenytoin 10% cream and used this cream for several weeks. Burning pain was reduced by 50% to 60%, resulting in a much improved sleep. The onset of analgesia starts around five minutes after the application of phenytoin 10% cream and in this case lasts for around 20 hours. Plasma levels of phenytoin, measured in 15 comparable patients were below the level of detection, ruling out systemic analgesia. Our hypothesis is that topical phenytoin influences epidermal targets such as nociceptors, small nerve fibers and keratinocytes, all which play a role in the pathogenesis of pain in SFN.

scholarly journals Dorsal Column Stimulation Treats Pain from Chemotherapy-induced, Small Fiber Neuropathy

2017 ◽  
pp. 57-61
Author(s):  
David Dickerson
Keyword(s):  
Spinal Cord ◽  
Dorsal Column ◽  
Nerve Fibers ◽  
Small Fiber Neuropathy ◽  
Autonomic Nerve ◽  
Vitamin Deficiencies ◽  
Small Fiber ◽  
Analgesic Regimen ◽  
Number Of Patients ◽  
Dorsal Column Stimulation

Small fiber neuropathy (SFN) is a disorder of small afferent nerve fibers that can result in debilitating pain and functional limitations. There are many etiologies including, but not limited to, diabetes, vitamin deficiencies, infections, and exposure to neurotoxic drugs such as chemotherapeutics. The constellation of signs and symptoms overlap with other disease states leading to potential misdiagnosis. New tests including histologic studies of skin biopsies and autonomic nerve tests have emerged in the last 20 years improving differentiation between these disease processes and SFN. Multiple chemotherapeutic medications have been implicated in causing SFN, including vincristine which was the causative agent in this case report. The exact incidence of chemotherapy-induced peripheral neurotoxicity (CIPN) is currently unknown, but according to some publications it has been reported to be as high as 40% in patients that have been treated with chemotherapy. As the number of cancer survivors continues to grow, the number of patients with painful SFN will potentially increase. Devising an effective analgesic regimen for patients with painful SFN can be difficult, and often requires the pain physician to employ multiple pharmacologic and non-pharmacologic therapies. Treatments include analgesics from several drug classes: antidepressants, opioids, and anticonvulsants. Often times however, more advanced interventional techniques must be employed as effective pain control may be limited by medication side effects or inadequate return of function. While dorsal column stimulation was approved for a limited number of applications, a number of new applications are reported in the literature. In this paper, we present a case of vincristineinduced SFN successfully treated with neuromodulation via spinal cord stimulator. Key words: Vincristine, vinblastine, chemotherapy- induced neuropathy, chronic pain, spinal cord stimulation, dorsal column stimulation, neuromodulation, small fiber neuropathy, neuropathic pain

Erythromelalgia Linked to Small Fiber Neuropathy

2006 ◽  
Vol 37 (5) ◽  
pp. 38
Author(s):  
JANE SALODOF MACNEIL
Keyword(s):  
Small Fiber Neuropathy ◽  
Small Fiber
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