Small Fiber Neuropathy Clinical Trials 2023

What Are Small Fiber Neuropathy Clinical Trials?

Small fiber neuropathy is a rare genetic peripheral nervous system disorder characterized by irregular intensity chronic neuropathic pain, generally accompanied by autonomic nervous system alterations. This disease affects myelinated (Aδ) and unmyelinated (C) nerve fibers of small caliber. Its causes can be primary or secondary to metabolic disorders, infections, autoimmune, neurological, or toxic diseases.

The usual neurophysiological studies are usually negative. The diagnosis can be made with complementary examinations difficult to access from primary care, such as microneurography, tests with sensory stimuli, and others. However, the most widely used test is a skin biopsy. Treatment should be directed at the causes and neurological symptoms.

Given the variability of symptoms with which it can start, it is important to know this entity. Therefore, researchers from leading academic institutes have been studying it through small fiber neuropathy clinical trials to increase its clinical suspicion, guide its diagnosis, and offer possible treatment.

Why Is Small Fiber Neuropathy Being Studied Through Clinical Trials?

Small Fiber Neuropathy is probably underdiagnosed due to the low level of clinical suspicion and the difficulty in confirming its diagnosis, especially in forms that do not follow the pattern of length-dependent distribution.

In addition, it is sometimes susceptible to being confused with other conditions, such as fibromyalgia or large fiber neuropathies, because it can share some clinical manifestations with these conditions. This is why it is essential to make an adequate differential diagnosis for which more small fiber neuropathy clinical trials are done to deepen this condition synthetically and practically and facilitate its identification.

In addition, once diagnosed, the course of small fiber neuropathy is variable. Sometimes it progresses with the involvement of long myelinated fibers, such as in diabetic polyneuropathy. Given the complexity of the condition, researchers show an increased interest in determining the possible treatment methods for managing aggravating pain factors.

What Are The Types of Treatments Available For Small Fiber Neuropathy?

There are 2 fundamental pillars in treatment: treating the causes and the symptoms.

In neuropathy secondary to immune-mediated causes, symptoms may improve clinically after treatment with glucocorticoids. In some specific cases of patients with celiac disease or sicca syndrome, improvement has been observed after intravenous infusion of immunoglobulins.

Regarding diabetic patients, as well as to prevent other types of complications, glycemic control is essential.

In patients with sodium channel mutation, some small fiber neuropathy clinical trials have shown that blocking these channels with antiarrhythmic drugs can improve its symptoms.

Regarding the symptoms, neuropathic pain is usually treated with medications for neuropathic pain. However, the results are not entirely satisfactory. Tricyclic antidepressants can be used, although today, selective inhibitors of serotonin reuptake, such as duloxetine or venlafaxine, are a safer option.

In addition, the use of opioids (tramadol, oxycodone) can also be useful in the treatment of acute pain attacks as a second-line treatment for neuropathic pain.

Sometimes, given the lack of response to these treatments, resorting to more aggressive therapies, such as neural blocks, spinal stimulation, or even neurosurgical interventions, becomes necessary.

What Are Some Recent Breakthrough Clinical Trials For Small Fiber Neuropathy?

Below are some of the most notable cyclic vomiting syndrome clinical trials:

2019: A Clinical Trial to Determine Effective Symptomatic Treatment - This study was conducted to evaluate the effectiveness of lacosamide as a potential treatment for small fiber neuropathy-related pain in Nav1.7. The study found lacosamide as an effective, safe, and tolerated treatment for pain in Nav1.7, which also improved patients' sleep quality.

2016: Efficacy of Intravenous Immunoglobulin Therapy - This clinical trial is the first of its kind in evaluating the effectiveness of IV immunoglobulin therapy in patients with idiopathic small fiber neuropathy. The positive results of the research will find a new treatment option for the condition.

Who Are Some of The Key Opinion Leaders on Small Fiber Neuropathy Clinical Trials Research?

Bianca T. A. de Greef. PhD

Bianca T. A. de Greef is an academic researcher at the School of Mental Health and Neuroscience at Maastricht University. She has been contributing to research in small fiber neuropathy to determine effective symptomatic treatment of neuropathic pain in the condition.

Dr. Janneke G.J. Hoeijmakers MD, PhD

Dr. Hoeijmakers is a neuromyologist and researcher at the Maastricht University Medical Center. She has conducted multiple clinical trials to determine effective diagnostics, etiologies, and treatments for painful neuropathies and has been contributing to the field of small fiber neuropathy for years.