Transient receptor potential channel polymorphisms are associated with the somatosensory function in neuropathic pain patients.

Transient receptor potential channels are important mediators of thermal and mechanical stimuli and play an important role in neuropathic pain. The contribution of hereditary variants in the genes of transient receptor potential channels to neuropathic pain is unknown. We investigated the frequency of transient receptor potential ankyrin 1, transient receptor potential melastin 8 and transient receptor potential vanilloid 1 single nucleotide polymorphisms and their impact on somatosensory abnormalities in neuropathic pain patients.

Cortical disinhibition occurs in chronic neuropathic, but not in chronic nociceptive pain.

Background: The aim of this study was to examine the relationship between chronic neuropathic pain after incomplete peripheral nerve lesion, chronic nociceptive pain due to osteoarthritis, and the excitability of the motor cortex assessed by transcranial magnetic stimulation (TMS). Hence in 26 patients with neuropathic pain resulting from an isolated incomplete lesion of the median or ulnar nerve (neuralgia), 20 patients with painful osteoarthritis of the hand, and 14 healthy control subjects, the excitability of the motor cortex was tested using paired-pulse TMS to assess intracortical inhibition and facilitation. These excitability parameters were compared between groups, and the relationship between excitability parameters and clinical parameters was examined.

Sensory changes and loss of intraepidermal nerve fibers in painful unilateral nerve injury.

Objectives: Dysaesthesias is a common symptom in patients with neuropathic pain after peripheral nerve injury (PNI). In contrast to neuropathies with comparable symptoms there is little knowledge of the underlying mechanisms in PNI patients.

Methods: Quantitative sensory testing according to the German Research Network on Neuropathic Pain protocol, and changes in intraepidermal nerve fiber density were assessed in 15 patients with dysaesthesias after PNI of the lower limb.

Significant difference between three observers in the assessment of intraepidermal nerve fiber density in skin biopsy.

Background: The determination of Intraepidermal Nerve Fiber Density (IENFD) in skin biopsy is a useful method for the evaluation of different types of peripheral neuropathies. To allow a reliable use of the method it is necessary to determine interobserver reliability. Previous studies dealing with this topic used limited suitable statistical methods.

Habituation and short-term repeatability of thermal testing in healthy human subjects and patients with chronic non-neuropathic pain.

We investigated habituation effects during thermal quantitative sensory testing (tQST) using 8 repetitive measurements for thermal detection and pain thresholds. The same measurements were repeated two days later. 39 healthy subjects and 36 patients with chronic non-neuropathic pain syndromes (migraine, tension-type headache, non-radicular back pain) were enrolled.

Depression and changed pain perception: hints for a central disinhibition mechanism.

Although patients with a depressive disorder report often of pain, their sensitivity to experimental pain is controversial, probably due to differences in sensory testing methods and to the lack of normal values. Therefore, we used a standardized and validated comprehensive sensory testing paradigm to assess the peripheral and central nervous system performance in depressive patients compared to healthy controls and chronic pain patients with fibromyalgia syndrome (FMS), in which depression is a common comorbidity. Twenty-five depressive psychiatric inpatients (pain-free: n=20), 35 FMS outpatients and 25 healthy controls underwent quantitative sensory testing (QST), including thermal and mechanical detection and pain thresholds, pain sensitivity and responsiveness to repetitive noxious mechanical stimuli (wind-up).

Painful or painless lower limb dysesthesias are highly predictive of peripheral neuropathy: comparison of different diagnostic modalities.

Dysesthesias of the lower limbs are a common complaint of patients and may be indicative of peripheral neuropathy. Here we investigated the prevalence and type of neuropathy in patients presenting with this complaint and compared the diagnostic performance of different diagnostic modalities. Forty-two patients were recruited prospectively and underwent a clinical examination, nerve conduction studies, quantitative sensory testing (QST), and skin biopsy at the dorsum of the foot.

Detection of a characteristic painful neuropathy in Fabry disease: a pilot study.

Objective: Fabry disease (FD) is an X-linked lipid storage disorder showing a high prevalence and early occurrence of painful neuropathy. Early detection of this likely underdiagnosed disease is an important approach because a causal therapy is available.

Design: We used a quantitative sensory testing to determine the detailed somatosensory profile of male Fabry patients and compare this profile with somatosensory profiles of other painful sensory neuropathies (SN).

NeuroQuick--a novel bedside test for small fiber neuropathy?

Background: An appropriate bedside test for small fiber neuropathy does not exist so far. Cold hypaesthesia occurs as an early onset symptom, and the new handheld device NeuroQuick (NQ) was recently claimed to be a valid and reliable screening tool for its quantitative assessment.

Aims: Comparison of the NQ with standardized quantitative sensory testing (QST) in patients suffering from chronic painful dysaesthesia with and without pathological cold detection threshold (CDT).