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To compare overall physical function, including gait speed and peripheral nerve function, between diabetic chronic kidney disease (CKD) patients and nondiabetic CKD patients and to investigate the association between gait speed and peripheral nerve function in CKD patients.
Sixty adult CKD patients (35 with and 25 without diabetes), who received maintenance hemodialysis (HD), were included in this study. Demographic data, past medical history, current medical condition and functional data—usual gait speed, vibration perception threshold for the index finger (VPT-F) and the great toe (VPT-T), activity of daily living (ADL) difficulty, and peripheral neuropathy (PN) along with the degree of its severity—were collected and compared between the two groups. Correlations between the severity of PN and the impairment of other functions were identified.
Diabetic CKD patients showed significantly slower gait speed (p=0.029), impaired sensory function (VPT-F, p=0.011; VPT-T, p=0.023), and more frequent and severe PN (number of PN, p<0.001; severity of PN, p<0.001) as compared to those without diabetes. Usual gait speed had a significant negative correlation with the severity of PN (rho=−0.249, p=0.013). By contrast, VPT-F (rho=0.286, p=0.014) and VPT-T (rho=0.332, p=0.035) were positively correlated with the severity of PN. ADL difficulty was comparatively more frequent in the patients with more severe PN (p=0.031).
In CKD patients with maintenance HD, their gait speed, sensory functions, and peripheral nerve functions were all significantly impaired when they have diabetes, and the severity of PN was negatively correlated with their gait speed, sensory function, and ADL function. Adverse effects of diabetes impacted physical performance of CKD patients. The physical disability of those patients might be attributable to PN and its severity.
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To assess the reliability of quantitative muscle ultrasonography (US) in healthy subjects and to evaluate the correlation between quantitative muscle US findings and electrodiagnostic study results in patients with carpal tunnel syndrome (CTS). The clinical significance of quantitative muscle US in CTS was also assessed.
Twenty patients with CTS and 20 age-matched healthy volunteers were recruited. All control and CTS subjects underwent a bilateral median and ulnar nerve conduction study (NCS) and quantitative muscle US. Transverse US images of the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) were obtained to measure muscle cross-sectional area (CSA), thickness, and echo intensity (EI). EI was determined using computer-assisted, grayscale analysis. Inter-rater and intra-rater reliability for quantitative muscle US in control subjects, and differences in muscle thickness, CSA, and EI between the CTS patient and control groups were analyzed. Relationships between quantitative US parameters and electrodiagnostic study results were evaluated.
Quantitative muscle US had high inter-rater and intra-rater reliability in the control group. Muscle thickness and CSA were significantly decreased, and EI was significantly increased in the APB of the CTS group (all p<0.05). EI demonstrated a significant positive correlation with latency of the median motor and sensory NCS in CTS patients (p<0.05).
These findings suggest that quantitative muscle US parameters may be useful for detecting muscle changes in CTS. Further study involving patients with other neuromuscular diseases is needed to evaluate peripheral muscle change using quantitative muscle US.
Citations
To assess the prevalence of peripheral neuropathy in patients with rheumatoid arthritis (RA) having neuropathic symptoms, and to investigate the relationship between electrophysiological findings of peripheral neuropathy and clinical findings of RA.
Patients with a clinical diagnosis of RA and who had tingling or burning sensation in any extremity were electrophysiologically examined for evidence of peripheral neuropathy. Study parameters, including age, gender, laboratory parameters, duration of RA, and medication, were recorded. The symptoms and signs of neuropathy were quantified with the neuropathy symptom score, and the functional statuses of these patients were assessed.
Out of a total of 30 RA patients, 10 (33%) had peripheral neuropathy: 2 had bilateral carpal tunnel syndrome (CTS), 5 had unilateral CTS, 1 had sensory polyneuropathy, and 2 had motor-sensory polyneuropathy. The mean ages of the patients with and without peripheral neuropathy were 69.4 and 56.5 years, respectively (p<0.05). A significant relationship was found between peripheral neuropathy and anti-cyclic citrullinated peptide (anti-CCP) antibody. However, no relationship was found between peripheral neuropathy and the type of medication, RA duration, the patients' functional status, neuropathic symptoms, erythrocyte sedimentation rate, and C-reactive protein values.
Neuropathic symptoms are common in RA patients, and it is difficult to distinguish peripheral neuropathy symptoms from those of arthritis. Patients with RA, particularly elderly patients and anti-CCP antibody positive patients who complain of neuropathic symptoms should undergo electrophysiological examination.
Citations
Objective: The purpose of this study was to determine the difference of temperature effects on the nerve conduction variables and to obtain correction factors for temperature in demyelinated and normal peripheral nerves.
Method: The compound muscle action potentials (CMAPs) were recorded with wrist stimulation during cooling and warming in 10 control subjects and 13 subjects with demyelinating neuropathies. The temperature of cooling and warming were 18oC and 40oC, respectively. The time of cooling and warming were 60 minutes and composed of successive 4 sessions of 15 minutes. The skin temperature of thenar area, latency, amplitude, duration, and area of CMAPs were measured before and after each session of 15 minutes of cooling or warming.
Results: The time constants of parameters of CMAPs were of higher tendency in cooling than in warming. The time constants of latency of CMAP were higher in subjects with demyelinating neuropathy than in controls (p＜0.05): 33.3⁑4.0 minutes versus 27.2⁑2.2 minutes in cooling; 30.0⁑7.8 minutes versus 19.6⁑3.3 minutes in warming. The temperature correction factor of latency of CMAPs was 0.23⁑0.03 msec/oC in control and 0.33⁑0.06 msec/oC in subjects with demyelinating neuropathies (p＜0.05).
Conclusion: When studying a subject with demyelinating neuropathies, we should warm the extremity for more sufficient time than in normal subject, or may applicate a differenct temperature correction factors.
Objective: To investigate waveform changes of compound muscle action potentials (CMAPs) related to voluntary muscle contraction and alteration of muscle length and to evaluate the effect of peripheral neuropathy on temporal and spatial summations of CMAPs.
Method: The influence of voluntary muscle contraction and alteration of muscle length on CMAP was studied in 37 median nerves of 21 patients with median neuropathy.
Results: In patients with no apparent axonopathy, temporal summation was partially disturbed without significant change of spatial summation. Shortening of muscle length or voluntary contraction produced a physiologic improvement of spatial and temporal summations. There was a decrease in temporal and spatial summations, more prominent in temporal summation, with lengthening of the muscle. In axonopathy, spatial summation was markedly deteriorated with partial reduction of temporal summation. Spatial summation was not affected by the change of muscle length or voluntary contraction. Temporal summation was improved by muscle shortening or voluntary contraction and was decreased by muscle lengthening.
Conclusion: Peripheral neuropathy has an effects on physiological spatial and temporal summations of CMAPs. Temporal summation is preferentially decreased in cases without axonopathy. When axonopathy is apparent, spatial summation is profoundly disturbed with partial reduction of temporal summation.
Objective: To investigate the role of tendon reflex test in the diagnosis of diabetic peripheral neuropathy.
Method: Patellar tendon reflex (PTR) and achilles tendon reflex (ATR) were recorded in forty six diabetic patients and thirty seven normal adults by delivering tendon taps with an electric reflex hammer. Forty six diabetic patients were divided into two groups based on nerve conduction study and diabetic neuropathy score: group 1 consisted of nineteen patients with peripheral neuropathy, group 2 consisted of twenty seven patients without peripheral neuropathy. Multiple regression equations using latency as a variable dependent on age and height were used and upper crossing of the 3 standard deviation level with regression on height and age was considered abnormal.
Results: Mean latencies of PTR and ATR were prolonged in the diabetic patients in comparison with the controls (p＜0.01) and were prolonged in group 1 compared to group 2. In group 1, PTR was abnormal in 14 cases (sensitivity: 73.6%, specifity: 88%) and ATR was abnormal in 13 cases (sensitivity: 68.4%, specifity: 85.1%). In group 2, PTR was abnormal in 3 cases and ATR was abnormal in 4 cases.
Conclusion: Tendon reflex test would be a valuable supplement to conventional nerve conduction studies for detection of diabetic peripheral neuropathy, especially in the proximal segment.
Objective: The dorsomedial cutaneous nerve (DMCN) to the great toe is a branch of the medial dorsal cutaneous nerve, which originates from the superficial peroneal nerve. The objective of this study is to standardize the electrodiagnostic technique, and to investigate the usefulness of dorsomedial cutaneous nerve (DMCN) conduction study in patients with peripheral neuropathy.
Method: Sixty two legs in 31 normal adults and 56 legs in 28 patients with the clinical signs and symptoms as well as electrodiagnostic evidences of peripheral neuropathy were evaluated with the DMCN conduction study. The stimulating electrode was placed over the lateral 1/3 between medial and lateral malleoli and the active electrode was placed over 12 mm medial and 10 mm proximal to the extensor hallucis longus tendon over the 1st metatarsophalangeal joint.
Results: The mean values of DMCN conduction study in normal adults were 2.95⁑0.47 msec for onset latency, 3.58⁑0.43 msec for peak latency, 6.67⁑2.87μV in amplitude, and 12.96⁑1.17 cm for distance from active electrode to stimulation point. There were statistically significant differences between normal and patients groups in all parameters except the distance.
Conclusion: A method for DMCN conduction study was introduced which could be used as a valuable technique for the early evaluation of peripheral neuropathy.
Dysfunction of the autonomic nervous system is reported to occur at an incidence of 20% to 40% in diabetes. The clinical symptoms include orthostatic hypotension, vomiting, diarrhea, bladder dysfunction, male impotence, sweating, etc. Two simple noninvasive tests, sympathetic skin response (SSR) and R-R interval variation (RRIV), were used to assess autonomic functions. We performed SSR and RRIV on the diabetic patients and controls. The patients were classified into 4 groups (group I: without peripheral neuropathy or dysautonomia, group II: with dysautonomia only, group III: with peripheral neuropathy only, group IV: with both peripheral neuropathy and dysautonomia). We also tried to correlate their clinical dysautonomic symptoms and the results of nerve conduction studies (NCS) and of SSR and RRIV.
The subjects of this study were 82 diabetic patients, 20 to 73 years old with the mean age of 53, and 12 controls.
Latency, amplitude, and loss of SSR all showed a significant difference in relation to the dysautonomic symptoms. The loss of SSR in the foot showed a remarkable difference in group I.
In groups III and IV, three RRIVs (Valsalva ratio, E:I ratio, 30 : 15 ratio) showed a significant decrease compared with the control group, and in group II, only the 30:15 ratio showed a statistically significant decrease.
In conclusion, the changes in SSR and RRIV were significantly associated with the dysautonomia. Among these, loss of SSR in the foot and decrease in the 30 : 15 ratio were useful parameters for early detection of diabetic autonomic neuropathy without peripheral neuropathy.
Peripheral neuropathy constitutes a rare clinical manifestation in the neurofibromatosis. Eleven cases of peripheral neuropathy associated with the neurofibromatosis have been reported. We report a sensorymotor peripheral neuropathy in 2 cases of neurofibromatosis.
The importance of neuropathy in the pathogenesis of foot lesions has been well recognized in diabetes. Blood flow in ischemic limbs has been extensively investigated but the circulation of limbs affected by peripheral neuropathy has received little attention. Some studies on blood flow in peripheral neuropathy have shown a remarkable increase in resting flow, transcutaneous venous oxygen tension, and vascularity, along with loss of the spontaneous variations which occur normally with sympathetic activity of the foot in patients with diabetes. The aim of present study is to find out the effects of somatic and autonomic nervous function in early change of blood flow of foot in diabetic patients. We have studied fifty-one patients of non-insulin-dependent(type II) diabetes with no history of hypertension or diabetic foot ulcers. The evidence of neuropathy was screened by nerve conduction studies and sympathetic skin response of both lower extremities. Blood flow of dorsalis pedis and posterior tibial arteries was measured by portable doppler machine and presented as pressure index (ankle-to-arm systolic pressure ratio). The patients with sympathetic dysfunction showed significant decrease in pressure index compared to normal control and diabetic patients with normal sympathetic function, suggesting that changes of the blood flow occur in diabetic patients with sympathetic dysfunction.
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