Supercharging of the ulnar nerve: clinical and neurophysiological assessment at 2 years for nine proximal injuries.

II.

Diagnostic accuracy of the 5.07 monofilament test for diabetes polyneuropathy: influence of age, sex, neuropathic pain and neuropathy severity.

Introduction: There is a need for simple and cheap diagnostic tools for diabetic polyneuropathy (DPN). We aimed to assess the diagnostic accuracy of the 5.07/10 g monofilament test in patients referred to polyneuropathy assessments, as well as to examine how disease severity, age, sex and neuropathic pain (NP) impact diagnostic accuracy.

A man in his twenties with weakness and numbness in his legs.

Neuropathy can have many causes, some less well known than others. In this article, we present the case of a young man with progressive neurological deficit over several months. The cause was found to be an increasing social problem.

Accuracy of neuropathic pain measurements in patients with symptoms of polyneuropathy: validation of painDETECT, Self-Completed Leeds Assessment of Neuropathic Symptoms and Signs, and Douleur Neuropathique 4.

Pain is a common symptom in patients referred to polyneuropathy assessment. Diagnostic evaluation and choice of treatment may depend on whether the pain is likely to be neuropathic or not. This study aimed to investigate the diagnostic accuracy of 3 tools commonly used to differentiate between neuropathic and nonneuropathic pain.

The role of Nav1.7 in human nociceptors: insights from human induced pluripotent stem cell-derived sensory neurons of erythromelalgia patients.

The chronic pain syndrome inherited erythromelalgia (IEM) is attributed to mutations in the voltage-gated sodium channel (NaV) 1.7. Still, recent studies targeting NaV1.

Exonic mutations in SCN9A (NaV1.7) are found in a minority of patients with erythromelalgia.

Background and aim "Gain-of-function" mutations in voltage-gated sodium channel NaV1.7 have been linked to erythromelalgia (EM), characterized by painful hot and red hands and feet. We investigated the proportion of patients with EM that carry a mutation in NaV1.

SCN10A Mutation in a Patient with Erythromelalgia Enhances C-Fiber Activity Dependent Slowing.

Gain-of-function mutations in the tetrodotoxin (TTX) sensitive voltage-gated sodium channel (Nav) Nav1.7 have been identified as a key mechanism underlying chronic pain in inherited erythromelalgia. Mutations in TTX resistant channels, such as Nav1.

Complex regional pain syndrome following viper-bite.

Background: Complex regional pain syndrome (CRPS) may occur following fractures, surgery or different trauma. Development of CRPS following snake-bite has only been published in three reports (from Turkey, Nepal and Korea), although snake bites occur frequently world-wide. There has been no report from Western Europe.

Specific changes in conduction velocity recovery cycles of single nociceptors in a patient with erythromelalgia with the I848T gain-of-function mutation of Nav1.7.

Seven patients diagnosed with erythromelalgia (EM) were investigated by microneurography to record from unmyelinated nerve fibers in the peroneal nerve. Two patients had characterized variants of sodium channel Nav1.7 (I848T, I228M), whereas no mutations of coding regions of Navs were found in 5 patients with EM.

[Microneurography and research on peripheral neuropathic pain].

Background: Microneurography is a neurophysiological technique which enables recording from single peripheral nerve fibres in persons who are awake. The method is only used in research. We discuss how microneurography has been used to map nerve-fibre functions under normal circumstances and in chronic pain conditions.

Differential effects of low dose lidocaine on C-fiber classes in humans.

Unlabelled: The nonselective sodium channel blocker lidocaine is widely used as a local anesthetic but also systemically for treatment of postoperative and neuropathic pain. Voltage-gated sodium channels are crucial for action potential generation and conduction, and their availability controls the amount of activity-dependent conduction velocity slowing. This important axonal property, as assessed by microneurography, is used to differentiate human mechanoinsensitive (silent) nociceptors from the classical polymodal nociceptors.

High spontaneous activity of C-nociceptors in painful polyneuropathy.

Polyneuropathy can be linked to chronic pain but also to reduced pain sensitivity. We investigated peripheral C-nociceptors in painful and painless polyneuropathy patients to identify pain-specific changes. Eleven polyneuropathy patients with persistent spontaneous pain and 8 polyneuropathy patients without spontaneous pain were investigated by routine clinical methods.

Double spikes to single electrical stimulation correlates to spontaneous activity of nociceptors in painful neuropathy patients.

Multiple firing of C nociceptors upon a single electrical stimulus has been suggested to be a possible mechanism contributing to neuropathic pain. Because this phenomenon maybe based on a unidirectional conduction block, it might also be related to neuropathic changes without a direct link to pain. We investigated painful neuropathy patients using microneurography and analysed nociceptors for the occurrence of multiple spiking and spontaneous activity.

Large and small fiber dysfunction in peripheral nerve injuries with or without spontaneous pain.

Unlabelled: Few data have been available on the functional role of small fiber damage in patients with peripheral nerve injuries with and without spontaneous pain. The aim of the present study was to investigate the function of large myelinated nerve fibers as well as small nerve fibers in a material of 60 patients with peripheral nerve injuries in upper or lower extremities, 30 patients with spontaneous pain, and 30 patients without pain. Patients were questioned about the characteristics of pain and investigated clinically with EMG/neurography and assessment of thermal thresholds in the innervation territory of the lesioned nerve as well as in the contralateral area.

Role of TRPM8 and TRPA1 for cold allodynia in patients with cold injury.

Local cold injury often induces hypersensitivity to cold and cold allodynia. Sensitisation of TRPM8 or TRPA1 could be the underlying mechanisms. This was evaluated by psychophysics and axon-reflex-flare induction following topical menthol and cinnamaldehyde application in cold injury patients and healthy subjects.