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Background: Digital nerve injuries in children are not common, but they are considered to have an excellent prognosis, compared to adults, after nerve injury and repair. In studies including both children and adults age have been found to have an effect on outcome after nerve repair., Methods: We investigated in a retrospective follow up study the long-time result after digital nerve injury and repair in children, 1-16 years of age (n = 38), and evaluate if age influences outcome. A group with young children, 1-10 years of age (n = 18), was compared with a group with older children, 11-16 years of age (n = 20). A clinical evaluation to evaluate sensation and grip strength was performed and questionnaires were used [Disability of the Arm, Shoulder and Hand (DASH), Cold Sensitivity Severity Scale (CISS), VAS-function and VAS-cosmetic] in median 40 months (range 12-131 months) after the injury and repair., Results: All patient regained normal sensation. No correlations between age and monofilaments were found. Twenty children (52%) reported some problems with cold intolerance (i.e. CISS), but no other abnormal disability was found (i.e. DASH, VAS); again with no differences between the two groups., Conclusions: Children have an excellent long-term recovery after a digital nerve repair and without any influence of age., (Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Bullosis diabeticorum is a cutaneous manifestation of diabetes mellitus, mainly observed in the lower extremities in patients with longstanding disease. The etiology is unknown, but an association with neurologic or vascular disturbances has been suggested. We have reviewed a case of a 70-year-old man with rapid development of bullae in median nerve innervated fingertips following carpal tunnel release., (Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare clinical outcomes 5 years after carpal tunnel release among patients with and without diabetes., Methods: In a prospective consecutive series, 35 patients with diabetes (median age, 54 y; 15 type 1 and 20 type 2 diabetes) with carpal tunnel syndrome were age- and sex-matched with 31 control patients without diabetes (median age, 51 y) with idiopathic carpal tunnel syndrome. Exclusion criteria were other nerve entrapment, cervical radiculopathy, inflammatory joint disease, thyroid disorder, previous wrist fracture, and long-term exposure to vibrating tools. Participants were examined independently at baseline, 1 year, and 5 years after surgery for sensory function (Semmes-Weinstein), motor function (abductor pollicis brevis muscle strength and grip strength), cold intolerance, and completion of the Boston Carpal Tunnel Questionnaire symptom severity and functional status score., Results: Five years after surgery, the overall attendance rate for clinical examinations and completion of the Boston Carpal Tunnel Questionnaire were 86% and 95%, respectively. Between 1 and 5 years after surgery, there was a tendency toward a decrease in sensory function but an increase in motor function, with no statistically significant difference between groups. Cold intolerance demonstrated long-term significant improvement for patients with diabetes. The improvement in symptom severity and functional status score, as well as the large effect size, were maintained at 5 years in both patient groups., Conclusions: Long-term improvement in patients with diabetes remained after carpal tunnel release to the same extent as for patients without diabetes. Furthermore, improvement in cold intolerance in patients with diabetes suggests the potential for the long-term regeneration of small nerve fibers., Type of Study/level of Evidence: Prognostic I., (Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Aims: To compare the diagnostic usefulness of tuning fork, monofilament, biothesiometer and skin biopsies in peripheral neuropathy in individuals with varying glucose metabolism., Methods: Normoglycaemic, impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) individuals were recruited. Nerve conduction studies (NCS) and thermal threshold tests were performed. Vibrotactile sense was tested with a biothesiometer and a 128-Hz tuning fork. Touch/pressure perception was examined with a 10-g monofilament. Skin biopsies were performed and intraepidermal nerve fibres were quantified. Distal symmetric polyneuropathy (DSPN) was defined as neuropathy disability score ≥2 and abnormal NCS. Thermal threshold tests were used to define small nerve fibre neuropathy (sDSPN) in cases where NCS (large nerve fibres) were normal., Results: The prevalence of DSPN and sDSPN in the whole group (n=119) was 18% and 23%, respectively. For the biothesiometer, a cut-off of ≥24.5V had a sensitivity of 82% and specificity of 70% (AUC=0.81, 95% CI 0.71-0.91) when evaluating DSPN. An intraepidermal nerve fibre density cut-off of ≤3.39fibres/mm showed a sensitivity of 74% and specificity of 70% in the detection of sDSPN, whereas the sensitivity of the tuning fork and the biothesiometer were relatively low, 46% and 67%, respectively. When combining skin biopsies with the tuning fork, 10 more sDSPN cases were identified. Adding skin biopsy to the combination of the tuning fork and biothesiometer increased the sensitivity of finding sDSPN cases, but not DSPN, from 81% to 93%., Conclusion: Using a biothesiometer in clinical routine might be a sensitive method to detect large nerve fibre dysfunction in the lower extremity, whereas skin biopsies in combination with methods measuring vibrotactile sense could increase the diagnostic sensitivity of detecting peripheral neuropathy at an early stage., (Copyright © 2013 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.)

Objective: To compare nerve conduction study results, before and after surgical carpal tunnel release, in diabetic and non-diabetic patients., Methods: In a prospective study (2004-2007), we included 35 consecutive diabetic patients with carpal tunnel syndrome (CTS), who were age and gender matched with 31 non-diabetic patients having idiopathic CTS. Preoperatively, and at the 1 year follow-up, nerve conduction studies were performed of the median and ulnar nerve. Presence of neuropathy was based on abnormal preoperative neurophysiologic values in both the sural and the peroneal nerve., Results: Diabetic patients demonstrated significantly impaired nerve conduction parameters, before as well as after surgical carpal tunnel release, compared to non-diabetic patients. However, neurophysiologic recovery after carpal tunnel release was not different between the two patient groups or between diabetic patients with or without peripheral neuropathy. In general, the largest neurophysiologic recovery was demonstrated for parameters with the greatest impairment, but normal values were seldom reached., Conclusions: Marked neurophysiologic impairment of the median nerve, or signs of peripheral neuropathy, does not preclude significant recovery after carpal tunnel release in diabetic patients., Significance: Diabetic patients with CTS should be offered the same opportunities for surgical carpal tunnel release as non-diabetic patients., (2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Purpose: To compare the clinical outcome after carpal tunnel release in diabetic and nondiabetic patients., Methods: We evaluated a prospective, consecutive series of 35 diabetic patients (median age, 54 years; 15 with type 1 and 20 with type 2 diabetes) with carpal tunnel syndrome, who were age- and gender-matched with 31 nondiabetic patients (median age, 51 years) having idiopathic carpal tunnel syndrome. Exclusion criteria were other focal nerve entrapments, cervical radiculopathy, inflammatory joint disease, renal failure, thyroid disorders, previous wrist fracture, and long-term exposure to vibrating tools. Participants were examined independently at baseline (preoperatively) and 6, 12, and 52 weeks after surgery, including evaluating sensory function (Semmes-Weinstein), motor function (abductor pollicis brevis muscle strength and grip strength), pillar pain, cold intolerance, and patient satisfaction., Results: The number of patients with normal sensory function (pulp of index finger) increased notably in both patient groups from baseline (diabetic patients, 7 of 35; nondiabetic patients, 10 of 31) compared with the 52-week follow-up (diabetic patients, 25 of 35; nondiabetic patients, 24 of 31). Grip strength decreased temporarily at 6 weeks but recovered completely after 12 weeks. At the 52-week follow-up, mean grip strength (95% confidence interval) had improved significantly in both patient groups (diabetic patients: 3.0 kg [-0.3 to 6.2], nondiabetic patients: 3.4 kg [0.2 to 6.6]). Pillar pain correlated significantly with grip strength at the 6-week follow-up (r(s) = -0.41 to -0.54 [p < .05]). The number of patients reporting cold intolerance decreased over time (diabetic patients, 22 of 35 to 19 of 35; nondiabetic patients, 18 of 31 to 8 of 31), but decreased markedly less for the diabetic patients. Level of patient satisfaction was equal between groups. Comparing type 1 and type 2 diabetic patients, no important difference was noted on any test variables., Conclusions: Patients with diabetes have the same beneficial outcome after carpal tunnel release as nondiabetic patients. Only cold intolerance demonstrated a lesser extent of relief for diabetic patients., Type of Study/level of Evidence: Prognostic I.

The effects of controlled vibrations of defined frequency (80 Hz), acceleration (32 m/s2 root mean square), and duration (5 hours daily, 2 or 5 days) induced to the hind limb of rats on the regeneration potential in the sciatic nerve after a test crush lesion were determined. Exposure to vibration induced a marked and significant increase in outgrowth length of axons from the crush injury as evaluated after 3 and 6 days with the pinch reflex test. This effect was still observed 1 month but not 3 months after exposure to vibration. Even such a short duration of vibration exposure as 2 days induced an increased length of outgrowth. Such a conditioning effect may be due to local changes in the environment of the axons or to changes in the nerve cell bodies in the dorsal root ganglion. The results indicate that an alarm reaction exists in the nerve at a time point where no structural changes are observed in the nerve. By inducing such a conditioning lesion to nerve tissue, vibration represents a trauma corresponding to a crush lesion or transection of the nerve.

The hind leg of adult rats was exposed to vibrations (82 Hz; amplitude peak-to-peak 0.21 mm) for 4 hours during 5 consecutive days. Light and electron microscopic examination of the plantar and sciatic nerves were done immediately after the exposure period or after a 2- or 4-week recovery period. Light microscopic examination did not reveal any distinct signs of injury. However, ultrastructurally unmyelinated fibers in the plantar nerves showed distinct changes, with deranged axoplasmic structure and/or accumulation of smooth endoplasmatic reticulum. These changes were to a large extent reversible in 2 weeks and appeared normalized after a 4-week recovery period. No ultrastructural changes could be observed in the sciatic nerve. However, when the sciatic nerve was crushed after 5 days of vibration exposure, axonal outgrowth was increased 23% as compared with controls. These findings confirm that vibration induces nerve fiber damage, in this experimental model expressed as a "conditioning effect" contributing to increased regeneration potential of the corresponding neurones.

Effects of compression at low pressures on slow and fast axonal transport was investigated in rabbit vagus nerve. Proteins in the sensory fibres were radiolabelled by injection of [3H]leucine or [35S]methionine into the nodose ganglion. A small compression chamber and/or ligatures were applied around the cervical part of the vagus nerve for 8 h, at an appropriate time for the subsequent analysis of the effects of compression on both slow and fast transport of radiolabelled proteins. In normal nerves there were two waves of slowly transported proteins with rates of about 12-15 and 25-30 mm/day, respectively. SDS-polyacrylamide gel electrophoresis was used and confirmed that the main proteins which accumulated proximal to the ligatures had a molecular weight of 54 000-56 000. Neither compression of the nerve at 20 mm Hg nor sham-compression induced any statistically significant accumulation of slowly transported proteins at the site of compression. A higher pressure, i.e. 30 mm Hg, induced a marked but incomplete accumulation of slowly transported proteins. Fast transport was partially inhibited in some, but not all, nerves, when 20 mm Hg was applied for 8 h, in contrast to the lack of effect found previously with the same pressure applied for only 2 h. Despite these slight differences, the results indicate that both slow and fast transport are impaired by low pressure levels of around 20-30 mm Hg, which are comparable with those found in human compression neuropathies. The impaired provision of cytoskeletal elements to the distal axon may be of significance in the pathophysiology of nerve entrapment syndromes.

We have compared the anatomic and functional regeneration of a transected sciatic nerve following regrowth from its proximal stump through either preformed empty mesothelial chambers or autologous nerve grafts bridging a 10 mm gap. Within the mesothelial chambers an organized multifascicular nerve trunk forms between the proximal and distal stumps. After 3 months, distal segment cross sections from the mesothelial chamber and nerve graft groups did not differ with respect to axonal density or distribution of axonal diameters. Mean conduction velocities across the gaps were also similar, although the nerve graft group had a wider distribution of velocities. Little or no regeneration was evident when the gap between the nerve stumps was left empty. These results suggest that if the regrowing proximal stump is in an appropriate environment, it can form a well organized and oriented nerve trunk. In the mesothelial chambers, the regenerating nerve is surrounded by a loose cellular stroma and a small amount of interstitial fluid, which was found to contain trophic activity for cultured rodent sensory neurons. Such factors may also support nerve regeneration in vivo.

Effects of experimental compression at different pressures on retrograde axonal transport were studied in rabbit vagus nerve. Proteins in the sensory neurones were radiolabelled by injection of [3H]leucine into the nodose ganglion. Sixteen hours after labelling, a small compression chamber and/or ligatures were applied around the cervical part of the vagus nerve for 8 h. Compression of the vagus nerve at 20, 30 and 200 mm Hg pressure induced a graded inhibition of both retrograde and anterograde transport of the radiolabelled proteins. Neither retrograde nor anterograde transport was affected by the presence of the non-inflated chamber. The results indicate that compression at pressures similar to those found in human carpal tunnel syndrome can block retrograde axonal transport. The consequences of inhibition of retrograde and anterograde axonal transport for the metabolism in the nerve cell bodies are discussed.