1,721,013 research outputs found
Neurophysiological and histopathological evaluation of small fiber pathways as diagnostic characterization of neuropathic pain and autonom dysfunction syndromes
No full textThis manuscript is made up of two individual not related articles about peripheral neuropathic pain syndrome. The first article reports the effect on pain relief in patients with peripheral neuropathic pain after brachial plexus lesions or distal peripheral nerve injury using an implanted peripheral nerve stimulator applied directly on nerve branch using a peculiar surgical technique. Seven patients with post-traumatic lesion of brachial plexus or peripheral nerve complaining severe intractable pain were selected. Neuropathic pain diagnosis according with redefinition and the grading system of NEUPSIG (2008) was assessed. Conventional drugs for neuropathic pain and traditional surgical treatment were not effective. Patients underwent at baseline clinical evaluation with careful neuroalgological evaluation recording negative signs and positive phenomena, pain questionnaires, thermal-Quantitative Sensory Testing (QST). Surgical treatment consists in a new surgical technique for neurostimulator implant: quadripolar electrocatheters were placed directly on the sensory peripheral branch of nerve mainly involved into the ascellary cavity. To assess neuromodulation effect we perform clinical neuroalgological evaluation, pain scales and QST after 1 week and again after 1 month, and after each 6 months. No significant or unexpected adverse events occurred. The pain intensity dropped decrease from a NRS of 9±1.15 before surgery to 2.14±1.57 at 6-month of follow-up and to 2.57±1.13 at 12-months of follow-up (P < 0.001). We assessed after about 12 months with double-blind control with Neurostimulation turned off the restart of severe ongoing pain and paroxysms. These results expressed in details in the article show the safety and efficacy of this innovative technique in treatment of chronic and usually intractable severe pain in selected patients.
The second article reported a peculiar phenotype of cold pain in patients with small fiber neuropathies. The aim of study was to characterize the distinct pattern of pain phenomena in these patients and to compare clinical, neurophysiological and histological features in order to assess the underlying pain mechanisms. 9 patients with painful small fiber neuropathy (SFN) complaining cold pain were selected and compared with patients with SFN complaining burning pain. A complete neuroalgological examination, nerve conduction studies, pain questionnary (NPSI), thermal-Quantitative Sensory Testing (QST) battery and skin biopsy at distal and proximal sites were performed. Then L-menthol and cinnamaldeyd (CA), TRPM8 and TRPA1 receptors agonists respectively, were topically applied to the calf in two different days and the effect on pain (recorded with 11-point Likart scale for 20 minutes), thermal sensation, tactile sensation and skin flare size (skin area mm2) were evaluated. We compared the results with 15 healthy subjects and 10 patients with SFN with burning pain as the main pain quality. At baseline evaluation cold-SFN showed a cold hyperalgesia or cold allodynia at lower limb in a disto-proximal fashion associated with severe cold and mild warm hypoaesthesia. L-menthol induced no sensation in 5 of 9 cold-SFN patients and burning pain sensation in 4. The L-menthol responses (vasodilatation and flare) were significantly reduced or nearly abolished in the allodynic area in cold-SFN pts. The CA effects were less significative, it produced a slight burning sensation in 3 pts, tactile allodynia and heat hyperalgesia in 2 pts affected by cold SFN. Skin biopsy showed in patients with cold painful SFN more severe denervation of dermal nerves compared with burning SFN and MBP-positive fibers were reduced compared with burning-SFN. All the other findings were detailed in the article. In conclusion, this study showed the existence of a peculiar neuropathic phenotype of cold pain that could be explained by selective or predominant dysfunction of TRPM8 receptor and A-delta thinly myelinated nerve fibers. Furthermore a selective group of patients with SFN complaining burning feet as exclusive painful syndrome shown a prevalent involvement of TRPA1 receptor afferent
Skin biopsy as an additional diagnostic tool in non-systemic vasculitic neuropathy
No full textSural nerve biopsy is considered mandatory for
diagnosing non-systemic vasculitic neuropathy (NSVN).
This invasive technique may be associated with unpleasant
sequelae and cannot easily be repeated. Skin punch biopsy
from an affected area may be a less invasive and repeatable
diagnostic method. Here we assessed the potential diag-
nostic value of skin punch biopsies in NSVN by analyzing
skin biopsies in 20 patients with sural nerve biopsy-proven
NSVN and in 11 patients with non-inflammatory axonal
neuropathy. As further controls, skin biopsies were studied
in nine healthy volunteers. Five millimeter skin punch
biopsies were taken under local anesthesia from the distal
lateral calf and T cells and macrophages were quantified
after immunostaining. The diagnostic sensitivity and
specificity compared to sural nerve biopsy was determined
using receiver operating characteristic (ROC) analysis.
ROC analysis revealed that the highest sensitivity (94%)
and specificity (79%) for NSVN was obtained when peri-
vascular macrophages were quantified. Quantification of
scattered T cells yielded a sensitivity and specificity of
65%. Inflammatory cells were very rare in controls.
Quantification of inflammatory cells in skin biopsies may
thus be a sensitive and specific additional tool for diag-
nosing NSVN
Skin biopsy as a diagnostic tool in peripheral neuropathy
No full textSkin biopsy is a safe, minimally invasive, painless and cheap tool for providing diagnostic information on small nerve fibers, which are invisible to routine neurophysiological tests. Biopsy can be performed in hairy skin to investigate unmyelinated and thinly myelinated fibers and in glabrous skin to examine large myelinated fibers. Morphometric analysis of skin nerves is readily accomplished through the use of immunohistochemical techniques, and has proved to be reliable, reproducible and unaffected by the severity of neuropathy. One further advantage of skin biopsy over conventional nerve biopsy is that it allows somatic nerve fibers to be distinguished from autonomic nerve fibers. Morphological changes, axonal degeneration and abnormal regeneration occur in cutaneous nerves very early in the course of peripheral neuropathies, making skin biopsy a promising tool for investigating the progression of neuropathy and the effect of neuroprotective treatments in clinical practice and trials. This article reviews the techniques that are used to investigate the innervation of human skin, the possible uses of skin biopsy in diagnosing and monitoring peripheral neuropathies, and correlations between skin biopsy findings and those of other diagnostic methods
Post-anoxic Status epilepticus: Which variable could modify prognosis? A single-center experience
No full textThe diagnostic criteria for small fibre neuropathy: from symptoms to neuropathology
No full textThe diagnostic criteria for small fibre neuropathy: from symptoms to neuropathology Small fibre neuropathy (SFN), a condition dominated by neuropathic pain, is frequently encountered in clinical practise either as prevalent manifestation of more diffuse neuropathy or distinct nosologic entity. Aetiology of SFN includes pre-diabetes status and immune-mediated diseases, though it remains frequently unknown. Due to their physiologic characteristics, small nerve fibres cannot be investigated by routine electrophysiological tests, making the diagnosis particularly difficult. Quantitative sensory testing (QST) to assess the psychophysical thresholds for cold and warm sensations and skin biopsy with quantification of somatic intraepidermal nerve fibres (IENF) have been used to determine the damage to small nerve fibres. Nevertheless, the diagnostic criteria for SFN have not been defined yet and a 'gold standard' for clinical practise and research is not available. We screened 486 patients referred to our institutions and collected 124 patients with sensory neuropathy. Among them, we identified 67 patients with pure SFN using a new diagnostic 'gold standard', based on the presence of at least two abnormal results at clinical, QST and skin biopsy examination. The diagnosis of SFN was achieved by abnormal clinical and skin biopsy findings in 43.3% of patients, abnormal skin biopsy and QST findings in 37.3% of patients, abnormal clinical and QST findings in 11.9% of patients, whereas 7.5% patients had abnormal results at all the examinations. Skin biopsy showed a diagnostic efficiency of 88.4%, clinical examination of 54.6% and QST of 46.9%. Receiver operating characteristic curve analysis confirmed the significantly higher performance of skin biopsy comparing with QST. However, we found a significant inverse correlation between IENF density and both cold and warm thresholds at the leg. Clinical examination revealed pinprick and thermal hypoesthesia in about 50% patients, and signs of peripheral vascular autonomic dysfunction in about 70% of patients. Spontaneous pain dominated the clinical picture in most SFN patients. Neuropathic pain intensity was more severe in patients with SFN than in patients with large or mixed fibre neuropathy, but there was no significant correlation with IENF density. The aetiology of SFN was initially unknown in 41.8% of patients and at 2-year follow-up a potential cause could be determined in 25% of them. Over the same period, 13% of SFN patients showed the involvement of large nerve fibres, whereas in 45.6% of them the clinical picture did not change. Spontaneous remission of neuropathic pain occurred in 10.9% of SFN patients, while it worsened in 30.4% of them
Neurophysiological pattern in Guillain Barrè Syndrome: experience of 6 years in Ferrara
No full textNeurophysiological pattern in Guillain Barrè Syndrome: experience of 6 years in Ferrar
Itching syndrome as manifestation of neuropathic pain - A case report
No full textItch is a common manifestation in systemic diseases
such as malignancy, myeloproliferative disorders, uraemia,
and allergy. Recent microneurography studies showed that
itch is mediated by a distinct subset of C fibres, the ‘‘itch
fibres’’, that are exclusively sensitive to histamine. We
described the case of a 68-year-old woman complaining of
itch at trunk and legs with acute onset three years before our
first observation. Itching was induced by ambient warm and
was associated with a persisting burning-like heat sensation.
Extensive dermatologic and allergologic investigations were
negative unrevealing. Treatment with anti-histaminergic
and low-dosage oral steroids for 6 months did not modify
the clinical picture. Physical examination was negative.
Laboratory investigations revealed only neutrophilic leukocytosis,
whereas chemistry profile, thyroid-stimulating
hormone, serum and urine immunofixation, and screening
for immunologic, infectious, and neoplastic disease was
negative. Cerebrospinal fluid examination was normal.
Gabapentin (1200 mg/day) reduced itch severity from 10 to
5 of the visual analogue scale (VAS) at 1-month follow-up.
Nerve conduction study and needle electromyography was
normal. Quantitative sensory testing in foot and distal leg
disclosed warm hyperalgesia. Cutaneous blood flow by
laser Doppler flowmetry at distal legs showed abnormal
vasodilatation function induced by local heating. Skin biopsy
demonstrated reduced intraepidermal nerve fibre density at
the proximal thigh (8.7/mm) and normal value at the distal leg
(7.8/mm) with diffuse axonal swellings. Total body CT-scan
showed laterocervical and mediastinic lymphadenopathy.
The histological exam of axillary lymph nodes revealed Tlymphocitic
T-zone lymphoma (TZL). Itch is a common symptom
in lynphoproliferative disease. In our case, the distinctive
feature of itch, the histological impairment of small fibres and
the success of treatment, suggest the presence of uncommon
itching SFN
The importance of neurophysiological evaluation in diagnosis of persistent idiopathic facial pain
No full textThe results indicate the usefulness of performing all the described neuropahysiological examinations (large and small fiber) in selected orofacial-pain patients in order to improve the diagnosi
High-Definition 4K 3D Exoscope (ORBEYETM) in Peripheral Nerve Sheath Tumor Surgery: A Preliminary, Explorative, Pilot Study
No full textBackground: Surgery for peripheral nerve sheath tumors aims to preserve functional fascicles achieving gross-total resection. Increasing the visualization of anatomic details helps to identify the different layers and the tumor-nerve interface. The traditional microscope can present some limitations in this type of surgery, such as its physical obstruction. Objective: To present a proof-of-concept study about exoscope-guided surgery for schwannomas of the lower limbs, to analyze the advantages and disadvantages of the 4K, high-quality, 3-dimensional (3D) imaging. Methods: We analyzed 2 consecutive surgical cases of suspected schwannomas of the lower limbs using the ORBEYETM exoscope (Olympus). A standard operative microscope was also available in the operating room. All procedures were performed with neurophysiological monitoring, to identify functioning nerves and to localize the tumor capsule safest entry point. The cases are reported according to the PROCESS guidelines. Results: In both cases, we achieved a gross total resection of the schwannomas; the exoscope provided an excellent view of the anatomic details at tumor-nerve interface, as visible in intraoperative images and in the 3D-4K video supporting these findings. The surgeon's position was comfortable in both cases, although if the co-surgeon positioned himself in front of the first surgeon, the comfort was slightly reduced. The 4K monitor allowed a realistic, nontiring 3D vision for all the team. Conclusion: The ORBEYETM, after an adequate learning curve, can represent a feasible and comfortable instrument for nerve tumor surgery, which is usually performed in a single horizontal plane. Further and wider clinical series are necessary to confirm this first impression
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