Assessment of symptomatic diabetic patients with normal nerve conduction studies: Utility of cutaneous silent periods and autonomic tests

Background. Established electrophysiological methods have limited clinical utility in the diagnosis of small fiber neuropathy. The cutaneous silent period (CSP) may be useful as a method for the evaluation of smaller and unmyelinated fiber dysfunctions. Hyperlipidemia is a very rare cause of small fiber neuropathy. In this study, hyperlipidemia and small fiber neuropathy in symptomatic patients with normal nerve conduction studies were evaluated with autonomic tests and cutaneous silent periods. Methods. Twenty-five patients with clinically suspected small fiber neuropathy and 23 healthy volunteers were included. CSP latency and duration, as well as CSP latency difference of the upper and lower extremities, were examined. Two tests were used to assess the autonomic nervous system, namely, the R-R interval variation test in basal and profound breath conditions and the sympathetic skin response. Results. Twenty-five patients with clinically suspected small fiber neuropathy and normal nerve conduction studies were compared with 23 controls. In the upper extremities, patients had prolonged CSP latencies (P=0.034) and shortened CSP durations (P=0.039), whereas in the lower extremities, patients had shortened CSP durations (P=0.001). The expiration-to-inspiration ratios were also reduced in patients groups. There was no significant difference between sympathetic skin response latencies and amplitude of the case and control groups. Conclusion. Our findings indicate that CSP may become a useful technique for the assessment of small fiber neuropathy in hyperlipidemic patients.

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Glycemic Control and Clinico-Electrophysiological Severity of Diabetic Polyneuropathy

Journal of National Institute of Neurosciences Bangladesh ◽

10.3329/jninb.v5i2.43026 ◽

2019 ◽

Vol 5 (2) ◽

pp. 177-184

Author(s):

KM Nazmul Islam Joy ◽

ATM Hasibul Hasan ◽

Md Rafiqul Islam ◽

Farhana Kalam ◽

M Lutful Kabir ◽

...

Keyword(s):

Glycemic Control ◽

Diabetic Neuropathy ◽

Nerve Conduction ◽

Scoring System ◽

Diabetic Polyneuropathy ◽

Nerve Conduction Studies ◽

Clinical Severity ◽

Diabetic Patients ◽

Motor Neuropathy ◽

Clinical Scoring

Background: Diabetic polyneuropathy (DPN) has a significant positive correlation with poor glycemic control (HbA1c ≥7%). The clinical, biochemical and electrophysiological parameters of DPN in Bangladeshi citizens have not yet been explored elaborately Objective: The purpose of the study was to detect and categorize status of glycemic control of Bangladeshi people and to analyze its impact on clinical severity of DPN using Toronto Clinical Scoring System (TCSS) and electrophysiological severity by modified Michigan diabetic neuropathy score (MDNS). Methodology: This observational study was carried out on diabetic patients having probable DPN by purposive sampling, attending Neurology OPD of Dhaka Medical College Hospital, Dhaka, Bangladesh and Bangladesh Institute of Research & Rehabilitation in Diabetes, Endocrine & Metabolic Disorder (BIRDEM) Hospital, Dhaka, Bangladesh from July 2014 to June 2016. Clinical parameters were recorded and DPN was graded as “no neuropathy”, “mild”, “moderate” and “severe” neuropathy by the Toronto Clinical Scoring System (TCSS). A standard nerve conduction study was performed on each patient and electrophysiological grading according to modified Michigan diabetic neuropathy score (MDNS) was done. Diabetic status of patients was classified into “controlled” (HbA1c <7.0%) and “uncontrolled” (HbA1c ≥7.0%) groups and HbA1c level and the clinical & electrophysiological severity scores were compared and were analyzed. Results: Mean age of the patients was 57.2±9.37 years. 51.0% cases were males and 49% cases were females. The mean HbA1c in the study population was 7.6±0.94% and 56.0% patients had HbA1c≥ 7% .Motor nerve conduction studies revealed that both CMAP amplitudes and MNCV in the ulnar, peroneal and tibial nerves were reduced significantly in patients of uncontrolled (HbA1c≥7%) DM (p<0.001). Sensory nerve conduction studies revealed significant reduction in SNAP amplitudes of median and ulnar sensory and sural nerves in the uncontrolled group (p<0.001). Electrophysiologically, 65.43% patients had mixed sensory-motor neuropathy (p<0.00001). Clinically severe DPN patients were higher (45.2%) within the uncontrolled (HbA1C ≥7%) group (p<0.00001). Similarly, severity in electrophysiological grading was more in patients with uncontrolled DM (48.8%) (p<0.00001). Conclusions: Neuropathic severity, either clinically or electrophysiologically, was associated with higher values of HbA1c. Journal of National Institute of Neurosciences Bangladesh, 2019;5(2): 177-184

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Combined nerve conduction index in diabetic polyneuropathy

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2012000500005 ◽

2012 ◽

Vol 70 (5) ◽

pp. 330-334 ◽

Cited By ~ 3

Author(s):

Carlos Otto Heise ◽

Flavia Costa Nunes Machado ◽

Simone Consuelo de Amorim ◽

Sonia Maria de Toledo

Keyword(s):

Nerve Conduction ◽

Diabetic Polyneuropathy ◽

Nerve Conduction Studies ◽

The Other ◽

Diabetic Patients ◽

Lumbosacral Radiculopathy ◽

Standard Deviations ◽

Higher Sensitivity

Diabetic polyneuropathy can be confirmed by nerve conduction studies. The data can be analyzed in the form of a combined index instead of individual parameters. METHODS: The combined index included five parameters of nerve conduction studies commonly used for evaluation of polyneuropathies. We evaluated sensitivity in 100 diabetic patients with suspected polyneuropathy, and specificity in 200 non-diabetic patients with suspected lumbosacral radiculopathy. All results were expressed in number of standard deviations (SD). RESULTS: The sensitivity of the combined index was 81 or 74%, and specificity was 97 or 98%, using respectively -2.0 or -2.5 SD as cutoff. The range of sensitivity of the other parameters was 57-65% or 48-56%, and specificity range was 96-98% or 98-100%, using the same criteria. DISCUSSION: The combined index had higher sensitivity and equivalent specificity compared to isolated parameters.

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Carpal tunnel decompression in patients with normal nerve conduction studies

Journal of Hand Surgery (European Volume) ◽

10.1177/1753193419866646 ◽

2019 ◽

Vol 45 (3) ◽

pp. 260-264 ◽

Cited By ~ 1

Author(s):

Samuel P. Mackenzie ◽

Oliver D. Stone ◽

Paul J. Jenkins ◽

Nicholas D. Clement ◽

Iain R. Murray ◽

...

Keyword(s):

Carpal Tunnel Syndrome ◽

Clinical Features ◽

Carpal Tunnel ◽

Nerve Conduction Study ◽

Nerve Conduction ◽

Study Groups ◽

Nerve Conduction Studies ◽

Level Of Evidence ◽

Tunnel Syndrome ◽

Normal Nerve Conduction

Some patients present with typical clinical features of carpal tunnel syndrome despite normal nerve conduction studies. This study compared the preoperative and 1-year postoperative QuickDASH scores in patients with normal and abnormal nerve conduction studies, who underwent carpal tunnel decompression. Of the 637 patients included in the study, 19 had clinical features of carpal tunnel syndrome but normal nerve conduction studies, and underwent decompression after failure of conservative management. Preoperative QuickDASH scores were comparable in both groups (58 vs 54.8). However, there were significant differences between the normal and abnormal nerve conduction study groups in the QuickDASH at 1 year (34.9 vs 21.5) and change in QuickDASH postoperatively (23.1 vs 33.4). Patients with normal nerve conduction studies had comparable preoperative disability scores compared with those with abnormal studies. Although they had a significant improvement in QuickDASH at 1 year, this was significantly less than those with abnormal nerve conduction studies. Level of evidence: III

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Outcome of Carpal Tunnel Release in Diabetic Patients

Journal of Hand Surgery (European Volume) ◽

10.1016/0266-7681(94)90131-7 ◽

1994 ◽

Vol 19 (5) ◽

pp. 626-629 ◽

Cited By ~ 23

Author(s):

M. M. AL-QATTAN ◽

R. T. MANKTELOW ◽

C. V. A. BOWEN

Keyword(s):

Retrospective Study ◽

Peripheral Neuropathy ◽

Carpal Tunnel ◽

Nerve Conduction ◽

Complete Resolution ◽

Carpal Tunnel Release ◽

Nerve Conduction Studies ◽

Diabetic Patients ◽

Hand Symptoms

A retrospective study of 15 diabetic patients (20 hands), who underwent carpal tunnel release, was performed to determine the outcome. All patients had a minimum of 18 months of follow-up. Outcome was considered excellent if there was complete resolution of symptoms and this occurred in 35% of the treated hands. Eight hands (40%) had a good outcome with significant improvement of pre-operative symptoms. Outcome was considered poor when symptoms were minimally improved, unchanged, or worse after surgery and this occurred in 25% of treated hands. All hands with a poor final result had either no electrodiagnostic evidence of localized compression or only mild compression in pre-operative nerve conduction studies. It was postulated that the contribution of localized compression to pre-operative hand symptoms was less than the contribution of peripheral neuropathy in these hands.

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