Diagnostic contribution of multi-frequency vibrometry to detection of peripheral neuropathy in type 1 diabetes mellitus compared with nerve conduction studies.

AIM: The aim was to assess the use of multi-frequency vibrometry (MFV) in detecting diabetic peripheral neuropathy (DPN) in type 1 diabetes in comparison to nerve conduction studies (NCS) and neurothesiometer (NT). Our objectives were to examine how VPTs correlated with NCS parameters, evaluate the efficacy of MFV in distinguishing DPN as well as to investigate whether MFV procedure could be based on fewer frequencies. METHODS: Adults with type 1 diabetes with previous MFV examinations were recruited at Skåne University Hospital in Malmö, Sweden, between 2018 and 2020. Participants were examined regarding nerve function in the lower limbs through MFV, NT and NCS. RESULTS: A total of 66 participants (28 women and 38 men) with a median age of 50 (39 to 64) years were included in the study. Through NCS assessment, 33 participants (50%) were diagnosed with DPN. We found negative correlations between VPTs and all NCS parameters, where the strongest correlation was found between sural nerve amplitude and the 125 Hz frequency of MFV. A combination of four frequencies, two low (4 and 8 Hz) and two high (125 and 250 Hz), showed the highest classification efficacy (AUC 0.83, 95% CI 0.73-0.93). CONCLUSION: We conclude that a strong correlation exists between the sural nerve amplitude and the VPTs at 125 Hz and that VPT testing with MFV can be focused on only four frequencies instead of seven, thus shortening test time, to distinguish DPN in the lower limb.

Evaluation of Simple Algorithms for Proportional Control of Prosthetic Hands Using Intramuscular Electromyography.

Although seemingly effortless, the control of the human hand is backed by an elaborate neuro-muscular mechanism. The end result is typically a smooth action with the precise positioning of the joints of the hand and an exerted force that can be modulated to enable precise interaction with the surroundings. Unfortunately, even the most sophisticated technology cannot replace such a comprehensive role but can offer only basic hand functionalities. This issue arises from the drawbacks of the prosthetic hand control strategies that commonly rely on surface EMG signals that contain a high level of noise, thus limiting accurate and robust multi-joint movement estimation. The use of intramuscular EMG results in higher quality signals which, in turn, lead to an improvement in prosthetic control performance. Here, we present the evaluation of fourteen common/well-known algorithms (mean absolute value, variance, slope sign change, zero crossing, Willison amplitude, waveform length, signal envelope, total signal energy, Teager energy in the time domain, Teager energy in the frequency domain, modified Teager energy, mean of signal frequencies, median of signal frequencies, and firing rate) for the direct and proportional control of a prosthetic hand. The method involves the estimation of the forces generated in the hand by using different algorithms applied to iEMG signals from our recently published database, and comparing them to the measured forces (ground truth). The results presented in this paper are intended to be used as a baseline performance metric for more advanced algorithms that will be made and tested using the same database.

Preoperative Electrophysiology in Patients With Ulnar Nerve Entrapment at the Elbow-Prediction of Surgical Outcome and Influence of Age, Sex and Diabetes.

The impact of preoperative electrophysiology on outcome of surgical treatment in ulnar nerve entrapment at the elbow (UNE) is not clarified. Our aim was to evaluate influence of preoperative electrophysiologic grading on outcome and analyse how age, sex, and in particular diabetes affect such grading. Electrophysiologic protocols for 406 UNE cases, surgically treated at two hand surgery units reporting to the Swedish National Quality Register for Hand Surgery (HAKIR; 2010-2016), were retrospectively assessed, and graded as normal, reduced conduction velocity, conduction block or axonal degeneration. Outcome of surgery after primary and revision surgery was evaluated using QuickDASH and a doctor reported outcome measure (DROM) grading. No differences in QuickDASH or DROM were found between the four groups with different electrophysiologic grading preoperatively, or at three and 12 months or at follow up, respectively. When dichotomizing the electrophysiologic grading into normal and pathologic electrophysiology, cases with normal electrophysiology had worse QuickDASH than cases with pathologic electrophysiology preoperatively (p=0.046). Presence of a conduction block or axonal degeneration indicated a worse outcome by DROM grading (p=0.011). Primary surgeries had electrophysiologic more pronounced nerve pathology compared to revision surgeries (p=0.017). Cases of older age, men, and those with diabetes had more severe electrophysiologic nerve affection (p<0.0001). In the linear regression analysis, increasing age (unstandardized B=0.03, 95% CI 0.02-0.04; p<0.0001) and presence of diabetes (unstandardized B=0.60, 95% CI 0.25-0.95; p=0.001) were associated with a higher risk of a worse electrophysiologic classification. Female sex was associated with a better electrophysiologic grading (unstandardized B=-0.51, 95% CI -0.75- -0.27; p<0.0001). We conclude that older age, male sex, and concomitant diabetes are associated with more severe preoperative electrophysiologic nerve affection. Preoperative electrophysiologic grade of ulnar nerve affection may influence surgical outcome.

A database of multi-channel intramuscular electromyogram signals during isometric hand muscles contractions.

Hand movement is controlled by a large number of muscles acting on multiple joints in the hand and forearm. In a forearm amputee the control of a hand prosthesis is traditionally depending on electromyography from the remaining forearm muscles. Technical improvements have made it possible to safely and routinely implant electrodes inside the muscles and record high-quality signals from individual muscles. In this study, we present a database of intramuscular EMG signals recorded with fine-wire electrodes alongside recordings of hand forces in an isometric setup and with the addition of spike-sorted metadata. Six forearm muscles were recorded from twelve able-bodied subjects and nine forearm muscles from two subjects. The fully automated recording protocol, based on command cues, comprised a variety of hand movements, including some requiring slowly increasing/decreasing force. The recorded data can be used to develop and test algorithms for control of a prosthetic hand. Assessment of the signals was done in both quantitative and qualitative manners.

Neurophysiological recovery 5 years after carpal tunnel release in patients with diabetes.

INTRODUCTION: The long-term results of neurophysiological recovery after carpal tunnel release in patients with diabetes have not been studied. METHODS: Thirty-five patients with diabetes and carpal tunnel syndrome (CTS) were matched with 31 patients without diabetes who had idiopathic CTS, and 27 and 30 patients, respectively, participated in this follow-up study. Nerve conduction results at 5 years were compared with previously published results at baseline and 1 year. RESULTS: Significant neurophysiological improvement continued from 1 to 5 years after carpal tunnel release for patients with and without diabetes. However, wrist-palm sensory conduction velocity was still abnormal for 85% and 43% of patients with and without diabetes, respectively. Although diabetes had an impact on 4 of 10 measured neurophysiological parameters, the influence of peripheral neuropathy seemed insignificant. DISCUSSION: After carpal tunnel release, significant long-term neurophysiological improvement is possible for patients with diabetes, and it is not influenced by the presence of peripheral neuropathy. Muscle Nerve 56: E59-E64, 2017.

Impact of smoking and preoperative electrophysiology on outcome after open carpal tunnel release.

BACKGROUND: The aim was to evaluate the influence of smoking and preoperative electrophysiology on the outcome of open carpal tunnel release. METHODS: This retrospective observational study evaluated the outcome in 493 patients (531 hands) primary operated for carpal tunnel syndrome. Data were collected from medical records, health evaluations, and QuickDASH questionnaires before surgery and 1 year after. RESULTS: Smokers had a higher QuickDASH score preoperatively as well as postoperatively, but the change in total score did not differ. The odds of having a postoperative QuickDASH score >10 were 2.5 times higher in smoking patients than in non-smoking patients. In 124/493 patients (25%), no clinically significant improvement was seen. Normal and extreme preoperative electrophysiology values were associated with higher postoperative scores. No correlation was found between preoperative QuickDASH scores and preoperative electrophysiology values. CONCLUSIONS: Smokers with carpal tunnel syndrome experience more symptoms preoperatively. Smokers have remaining symptoms after surgery. There is no correlation between preoperative QuickDASH scores and preoperative electrophysiology values. Patients with normal or near to normal preoperative electrophysiology results have limited improvement after surgery.

Outcome after carpal tunnel release: impact of factors related to metabolic syndrome.

OBJECTIVE: The standard surgical treatment of carpal tunnel syndrome (CTS), with an open carpal tunnel release, is reported to relieve symptoms in most patients. In a retrospective observational study, outcome after open carpal tunnel release was evaluated, focusing on factors related to the metabolic syndrome: diabetes, hypertension, obesity (BMI ≥30) and statin treatment. METHODS: Results from 493 out of 962 patients (531/1044 hands) operated for CTS during 18 months that had filled in QuickDASH questionnaires before and 1-year after surgery were included in the study. RESULTS: Patients with diabetes (n = 76) had higher QuickDASH scores pre- (56 [36-77]; i.e. median [interquartile range]) and postoperatively (31 [9-61]) compared to patients without diabetes (48 [32-66]; p < 0.05 and 16 [5-43]; p < 0.001), but the change in total score was equal. A higher proportion of patients with diabetes had a postoperative score of >10 (74% vs 61%; p < 0.05). The odds of having a change in QuickDASH score <8 was 2.6-times higher in patients with polyneuropathy than in patients without polyneuropathy. Patients with hypertension, obesity, or statin treatment had a similar improvement after surgery as patients without these factors. CONCLUSIONS: Patients with diabetes without neuropathy, as well as patients with hypertension, obesity or statin treatment, and CTS can expect the same effects of open carpal tunnel release as otherwise healthy patients. Patients with diabetic neuropathy and CTS did not experience the same improvement as otherwise healthy patients and should be informed about the risk of an unsatisfactory outcome.

Outcome of simple decompression of the compressed ulnar nerve at the elbow - influence of smoking, gender, and electrophysiological findings.

BACKGROUND: Compression of the ulnar nerve at elbow is frequently treated with simple decompression. Knowledge about factors influencing results of surgery of the nerve is limited and contradictory. The primary aim was to evaluate outcome of simple decompression of the nerve using a QuickDASH questionnaire, and to investigate any influence of smoking, gender, and preoperative electrophysiological findings. A second aim was to estimate the relation between QuickDASH score and a clinical assessment of outcome by the surgeon. METHODS: Patients who were operated on with simple decompression of the ulnar nerve, excluding reoperations, from September 2009 to February 2011 were evaluated before and at 1 year after surgery using QuickDASH. Data were collected from medical records and from a self-reported health declaration. RESULTS: There were no differences in QuickDASH scores or change in total score between smokers and non-smokers or between women and men. Nerve pathology, assessed by preoperative electrophysiology, did not affect outcome. The surgeon's assessment of outcome mirrored QuickDASH score. Among all patients, 12/33 (36%) did not have a decrease in QuickDASH score >8, which is considered as a minimal clinically important difference. CONCLUSION: Smoking, gender, and preoperative electrophysiological findings do not affect outcome of surgery. There are a high number of patients who do not benefit from simple decompression of the ulnar nerve at the elbow. Patients who are planned for surgery should be informed that there is a risk for persistent problems. A simple outcome assessment by the surgeon mirrors QuickDASH score at 1 year.

Case report: Intraneural perineurioma of the sciatic nerve in an adolescent - strategies for revealing the diagnosis.

Diagnosis of intraneural conditions can be revealed by a combination of clinical examination, electrophysiology, magnetic resonance imaging (MRI), and targeted fascicular biopsy with subsequent microscopic analyses.

Carpal tunnel release in patients with diabetes: a 5-year follow-up with matched controls.

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.