Cardiovascular autonomic neuropathy in patients with type 2 diabetes with and without sensorimotor polyneuropathy

Background and Aims

Cardiovascular autonomic neuropathy (CAN) in patients with diabetes is associated with poor prognosis. We aimed to assess signs of CAN and autonomic symptoms and to investigate the impact of sensorimotor neuropathy on CAN by examining type 2 diabetes patients with (DPN [distal sensorimotor polyneuropathy]) and without distal sensorimotor polyneuropathy (noDPN) and healthy controls (HC). Secondarily, we aimed to describe the characteristics of patients with CAN.

Methods

A population of 374 subjects from a previously described cohort of the Danish Centre for Strategic Research in Type 2 Diabetes (DD2) were included. Subjects were examined with the Vagus™ device for the diagnosis of CAN, where two or more abnormal cardiovascular autonomic reflex tests indicate definite CAN. Autonomic symptoms were assessed with Composite Autonomic Symptom Score 31 (COMPASS 31) questionnaire. DPN was defined according to the Toronto consensus panel definition.

Results

Definite CAN was present in 22% with DPN, 7% without DPN and 3% of HC, and 91% of patients with definite CAN had DPN. Patients with DPN and definite CAN reported higher COMPASS 31 scores compared to patients with noDPN (20.0 vs. 8.3, p < 0.001) and no CAN (22.1 vs. 12.3, p = 0.01). CAN was associated with HbA1c and age in a multivariate logistic regression analysis but was not associated with IEFND or triglycerides.

Interpretation

One in five patients with DPN have CAN and specific CAN characteristics may help identify patients at risk for developing this severe diabetic complication. Autonomic symptoms were strongly associated with having both DPN and CAN, but too unspecific for diagnosing CAN.     

The natural history of diabetic peripheral neuropathy determined by a 12 year prospective study using vibration perception thresholds

The development and long term progression of diabetic peripheral neuropathy was studied using vibration perception threshold (VPT) as a validated measure. Three hundred and ninety-two patients had a normal age corrected VPT (12.1 +/- 3.7 volts) at baseline, with an age corrected logarithmic VPTscore < 12. 19.9% developed an abnormal VPT over a 12 year period, increasing from 14.2 +/- 3.7 volts (VPTscore 10.4 +/- 0.6) at baseline to 35.9 +/- 9.5 volts (VPTscore 12.6 +/- 0.45) at follow up (P = 0.0001), and from 10.1 +/- 3.7volts (VPTscore 9.4 +/- 0.8) to 14.2 +/- 4.7 (VPTscore 9.8 +/- 0.8) in the rest. Over 80% thus retained a "normal" VPT after a mean diabetes duration of 16 years despite only average glycaemic control, suggesting that non-ideal long term glycaemic control leads to neuropathy in a subset of predisposed patients. VPT was correlated in 123 diabetic patients with definitive criteria for neuropathy and a range of quantitative sensory and autonomic tests. 62/63 patients with abnormal VPT fulfilled neuropathy criteria; of patients with normal VPT who fulfilled neuropathy criteria, all had at least one abnormal thermal threshold test result. We conclude that a combination of log-transformed VPT values (VPTscore > 10.1) and thermal thresholds can identify diabetic patients at risk of developing peripheral neuropathy and select patients likely to benefit from prophylaxis in clinical trials.     

Pupillography refines the diagnosis of diabetic autonomic neuropathy

Although diabetic autonomic neuropathy involves most organs, diagnosis is largely based on cardiovascular tests. Light reflex pupillography (LRP) non-invasively evaluates pupillary autonomic function. We tested whether LRP demonstrates autonomic pupillary dysfunction in diabetics independently from cardiac autonomic neuropathy (CAN) or peripheral neuropathy (PN). In 36 type-II diabetics (39-84 years) and 36 controls (35-78 years), we performed LRP. We determined diameter (PD), early and late re-dilation velocities (DV) as sympathetic parameters and reflex amplitude (RA) and constriction velocity (CV) as parasympathetic pupillary indices. We assessed the frequency of CAN using heart rate variability tests and evaluated the frequency of PN using neurological examination, nerve conduction studies, thermal and vibratory threshold determination. Twenty-eight (77.8%) patients had abnormal pupillography results, but only 20 patients (56%) had signs of PN or CAN. In nine patients with PN, only pupillography identified autonomic neuropathy. Four patients had pupillary dysfunction but no CAN or PN. In comparison to controls, patients had reduced PD, late DV, RA and CV indicating sympathetic and parasympathetic dysfunction. The incidence and severity of pupillary abnormalities did not differ between patients with and without CAN or PN. LRP demonstrates sympathetic and parasympathetic pupillary dysfunction independently from PN or CAN and thus refines the diagnosis of autonomic neuropathy in type-II diabetics.     

Sympathetic and electrochemical skin responses in the assessment of sudomotor function: a comparative study

ObjectivesThe sympathetic skin response (SSR) is a well-established test, whereas the electrochemical skin conductance (ESC) is still under evaluation. Our aim was therefore to assess the diagnostic accuracy of ESC to detect abnormal sudomotor function, using SSR as a reference test.MethodsA cross sectional observational study was performed of 61 neurological patients assessed for possible sudomotor dysfunction and 50 age-matched healthy controls (HC). Patients with diagnoses of vasovagal syncope (VVS, n=25), Parkinson's disease (PD, n=15), multiple system atrophy (MSA, n=11) and peripheral neuropathies (PN, n=10) were included. Sudomotor function was assessed with SSR and ESC tests in all participants. The absence of SSR in the palms or soles indicates abnormal sudomotor function. Receiver operating characteristic (ROC) analysis was used to assess the diagnostic value of the ESC. Cardiovascular autonomic (CV-Aut) function was evaluated through the Ewing score, based on the following tests: Heart rate change with deep breathing, Valsalva ratio, 30:15 ratio, blood pressure changes on standing and during isometric exercise. A Ewing score ≥ 2 indicates the presence of CV-Aut dysfunction.ResultsMean SSR amplitudes and ESC values showed differences between HC and patients with MSA or PN (p < 0.05), but not in patients with VVS or PD. Absence of SSR was associated with abnormal ESC (p < 0.05). Patients with abnormal CV-Aut dysfunction had lower ESC (p< 0.05). Palm ESC (P-ESC) and sole ESC (S-ESC) assessment had a sensitivity of 0.91 and 0.95 to predict sudomotor dysfunction, with a specificity of 0.78 and 0.85, respectively. The area under ROC curve was 0.905 and 0.98, respectively.ConclusionsESC in palms and soles has a high diagnostic accuracy for sudomotor dysfunction as detected by absent SSR in patients with MSA and PN.     

Assessment of autonomic function in a cohort of patients with ANCA-associated vasculitis

Objective

To assess symptoms and objective parameters of autonomic dysfunction (AD) in patients with ANCA-associated vasculitides.

Methods

Symptoms and objective parameters of AD were assessed in patients with ANCA-associated vasculitis and in age-matched healthy controls. Autonomic symptoms were explored by COMPASS31, a validated questionnaire addressing symptoms of six autonomic domains (orthostatic, vasomotor, secretomotor, gastrointestinal, pupillomotor, and bladder dysfunction). Objective autonomic parameters consisted of expiratory/inspiratory (E/I) ratio during the deep breathing test (DBT), blood pressure response to cold pressor test (CPT), and skin conductance changes during mental arithmetic.

Results

27 patients and 27 healthy controls have been enrolled. 27 patients and 27 controls completed COMPASS31. 21 patients and 18 controls underwent objective autonomic testing. Vasculitis patients had significantly higher COMPASS31 total scores than controls (median 10.4 vs 3.0; p = 0.005). In the sub-domain analysis, significant differences were seen in the vasomotor and the bladder domain (p = 0.004; p < 0.001, respectively). No correlation was found between COMPASS31 score and disease duration, number of affected organs, or Birmingham vasculitis activity score (BVAS). There was no significant difference in any of the objective autonomic parameters between patients and controls. In a subgroup analysis, no difference in objective autonomic parameters was found between patients with active disease (n = 12) and patients in remission (n = 7).

Conclusion

Patients with ANCA-associated vasculitides commonly have symptoms of autonomic dysfunction that are independent of disease duration and disease severity. However, at least in this single-centre observation, there was no evidence of impaired autonomic regulation in three autonomic function tests in vasculitis patients.

     

交感皮肤反应对糖尿病自主神经病变的诊断价值

目的探讨交感皮肤反应（sympathetic skin response,SSR）在糖尿病自主神经病变诊断中的价值。方法对186例糖尿病周围神经病（Diabetic peripheral neuropathy,DPN）患者和203例糖尿病非DPN患者进行SSR检测,同时对102例健康人进行SSR检测。结果SSR起始潜伏期异常率高于波幅异常率,下肢的异常率高于上肢异常率。DPN患者中,174例（93.5%）SSR异常,其中32例未引出SSR,142例起始潜伏期延长,109例波幅下降。203例DM非DPN患者中,46例（22.7%）SSR起始潜伏期延长和/或波幅下降,其中19例有出汗异常,4例在检查后数月出现出汗异常。结论SSR是早期诊断糖尿病自主神经病变的敏感手段,可发现亚临床神经病,并与病情进展相吻合。     

Neuropathy is a major contributing factor to diabetic erectile dysfunction

Abstract

Erectile dysfunction (ED) in diabetes is multifactorial. So far, the impact of neuropathy has not been well determined. This study was performed to assess the frequency of abnormal neurophysiological tests in patients with ED due to diabetes compared to patients with ED due to nondiabetic neuropathies in order to estimate the contribution of neuropathy in diabetic ED. Forty-nine men with ED were studied. We classified ED as 'diabetic', 'neuropathic' or 'ED of other origin'. 26.6% of the men fulfilled the criteria of diabetic ED, 42.9% had neuropathic ED. In every patient history taking, a questionnaire focusing on autonomic symptoms other than ED, clinical examination, nerve conduction studies (NCS), sphincter ani electromyography (EMG), heart rate variability testing (HRV) and quantitative sensory testing (QST) was performed. Vascular function was assessed by the intracavernosal prostaglandin E1 (PGE1) injection test. The frequency of abnormal results in diabetic and neuropathic patients was compared. Vascular function was abnormal in only one patient with diabetic ED and three patients with neuropathic ED. Both groups had similar frequencies of autonomic symptoms other than ED (64% in diabetic vs. 64% in neuropathic patients), abnormal EMG (33% vs. 40%) and abnormal QST (vibratory perception 83% vs. 84%, cold perception 9% vs. 19%, warm perception 42% vs. 43%). Abnormal clinical findings (50% vs. 33%), NCS (75% vs. 50%) and HRV (39% vs. 25%) were slightly, but not significantly more frequent in men with diabetic ED than neuropathic ED. The tests indicating neuropathy showed abnormalities in men with diabetic ED as frequently as in men with neuropathic ED. Some tests even suggested neuropathy more often in diabetic than in neuropathic ED. The findings support the hypothesis that neuropathy contributes significantly to the pathophysiology of ED in diabetes mellitus. [Neurol Res 2001; 23: 651-654]     

Early Detection Of Diminished Baroreflex Sensitivity In Diabetic Patients Without Evidence Of Cardiovascular Autonomic Neuropathy

Diabetic cardiovascular autonomic neuropathy (CAN) carries an increased risk of mortality. Decreased baroreflex sensitivity (BRS) has been identified as a predictor of increased mortality following myocardial infarction. We evaluated spontaneous BRS in 39 healthy control subjects (C: age (mean ± SEM): 41.5 ± 1.9 years) and 116 diabetic patients (64% Type 1, 36% Type 2; age: 45.8 ± 1.4 years; diabetes duration: 16.9 ± 1.0 years; HbA_1c: 9.2 ± 0.2%) using cross‐spectral analysis between systolic blood pressure and heart rate in the low‐frequency (LF) and high‐frequency (HF) bands as well as time domain (sequence) analysis in the supine and standing positions over 10 min. According to previously suggested definitions based on autonomic function tests (AFTs), 36 patients had definite CAN (CAN+: 3 of 7 indices abnormal), 13 had borderline CAN (CAN[+]: 2 of 7 indices abnormal), and 64 had no evidence of CAN (CAN?: 1 of 7 indices abnormal). Maximum gain in cross‐spectral LF band (standing) was significantly reduced in CAN? as compared with C (5.2 ± 0.4 vs. 7.2 ± 0.8 ms/mmHg, p < 0.05). Moreover, maximum gain in cross‐spectral HF band was significantly lower in CAN? than in C (supine: 12.0 ± 1.2 vs. 17.9 ± 2.5 ms/mmHg, p < 0.05; standing: 4.9 ± 0.5 vs. 8.7 ± 1.0 ms/mmHg, p < 0.05). The slope of the regression line between defined increases or reductions in systolic blood pressure and R‐R intervals was significantly reduced in CAN? compared to C (supine: 10.6 ± 0.7 vs. 14.2 ± 1.6 ms/mmHg, p < 0.05; standing: 5.6 ± 0.4 vs. 8.1 ± 0.7 ms/mmHg, p < 0.05). Similar differences were obtained when comparing the CAN? and CAN[+] groups, the latter showing significantly reduced BRS by both techniques (p < 0.05). In contrast, no such differences were noted when comparing the CAN[+] and CAN+ groups. In conclusion, reduced spontaneous baroreflex sensitivity is an early marker of autonomic dysfunction at a stage when autonomic function tests do not yet indicate the presence of CAN, while cases with borderline CAN show a degree of BRS abnormality that is comparable to the level seen in definite CAN. Prospective studies are needed to evaluate whether reduced BRS is a predictor of mortality in diabetic patients.     

Reappraisal of the diagnostic role of orthostatic hypotension in diabetes

Objective  Given the controversial aspects of orthostatic hypotension (OH) testing in diabetes, we evaluated the diagnostic role for cardiac autonomic neuropathy (CAN) and for nondipping of OH, defined according to a fall in systolic blood pressure (BP) ≥ 30 (30-OH) or ≥ 20 mmHg (20-OH). Methods  164 diabetic patients underwent 24 hours BP monitoring, three heart rate cardiovascular tests, and OH test. Results  Compared to 30 mmHg, the 20 mmHg criterion increased the frequency of OH from 11 to 19.5%. Both 30-OH and 20-OH were associated with CAN (χ ² = 30.5, P < 0.0001, and χ ² = 45.1, P < 0.0001, respectively) and nondipping (χ ² = 31.7, P < 0.0001, and χ ² = 17.2, P = 0.0001, respectively). ROC curve for orthostatic systolic BP fall provided an AUC of 0.79 ± 0.04 (95% CI 0.70–0.86) for diagnosing CAN and of 0.77 ± 0.05 (95% CI 0.66–0.86) for diagnosing nondipping. Both 30-OH and 20-OH showed a low sensitivity and high specificity for CAN [sensitivity 31%, specificity 98%, Likelihood Ratio for a positive result (LR⁺) 17.1; and sensitivity 50%, specificity 95%, LR⁺ 9.3, respectively], and for nondipping (sensitivity 40%, specificity 96%, LR⁺ 8.9, and sensitivity 47%, specificity 87%, LR⁺ 3.5, respectively), having 30-OH a higher LR⁺ in both cases. Interpretation  OH had only moderate diagnostic accuracy, with high specificity and low sensitivity, for CAN, diagnosed on the basis of heart rate cardiovascular tests, and—as a novel finding—also for nondipping. A different definition of OH did not substantially affect its diagnostic characteristics, with just a slightly greater ability of the 30 mmHg criterion to estimate the probability of CAN and nondipping.     

An advanced approach for the assessment of gastric motor function in long-term Type 1 diabetes mellitus with and without autonomic neuropathy

Gastric motor dysfunction is a frequent and deleterious long-term complication in diabetes mellitus (DM) but the exact contribution of diabetic autonomic dysfunction remains unclear. The aim of this study was to assess indices of gastric motor function in long-term Type 1 DM in the light of the presence and absence of autonomic neuropathy by means of an advanced dynamic scintigraphic technique. Gastric scintigraphy with condensed images of a short dynamic sequence was applied to 27 long-term Type 1 diabetic patients (duration > 10 years) and 15 control subjects. Two indices of gastric peristalsis, the frequency of contractions (FC) and amplitude of contractions (AC), were assessed scintigraphically together with half-time of gastric emptying (t 1/2). Five cardiac reflex tests were performed to study electrocardiogram (ECG)-based cardiac autonomic neuropathy (CAN). Mean AC was significantly decreased in diabetic patients compared to control subjects (13 ± 9 % vs. 28 ± 8 %, p < 0.005). Mean FC was comparable between diabetic patients and control subjects (3.1 ± 0.4 min⁻¹ vs. 3.1 ± 0.2 min⁻¹). Compared to control subjects, half-time of gastric emptying was significantly prolonged in diabetic patients (31 ± 17 min vs. 20 ± 3 min, p < 0.001). Mean AC, FC and t 1/2 did not differ significantly between diabetic patients with (n = 10) and without (n = 17) ECG-based CAN. Our study demonstrates that in both long-term Type 1 DM with and without autonomic neuropathy, the amplitude but not the frequency of gastric contractions, is frequently reduced. A delay of gastric emptying in Type 1 DM is confirmed although it was independent from the presence of cardiac autonomic neuropathy (CAN). Analyzing gastric motor function with dynamic scintigraphic techniques using condensed images is a promising clinical approach to further elucidate the mechanisms of impaired gastric motility in DM. Received: 25 July 2001, Accepted: 27 March 2002     

Electrocardiographic findings in sickle cell cardiovascular autonomic neuropathy

Background

There is a lack of data on the relationship between cardiovascular autonomic neuropathy (CAN) and electrocardiographic parameters in sickle cell anaemia.

Aims and objectives

The purpose of the study was to compare the electrocardiographic findings in adult sickle cell anaemia patients with CAN with those of patients without this complication.

Methods

A cross sectional study was done using 62 consecutively recruited sickle cell anaemia patients who met the inclusion criteria for the study. Cardiovascular autonomic dysfunction was determined based on abnormal values in at least two of five non-invasive tests: Valsalva manoeuver, heart rate variation during deep breathing, heart rate response to standing, blood pressure response to sustained hand grip, and blood pressure response to standing. The subjects were subsequently evaluated with electrocardiography.

Results

Sickle cell anaemia patients with CAN had statistically significantly increased P-wave duration (p?p?p?p?=?0.026, p?=?0.014, respectively). Significant correlations were noted between the severity of CAN [number of abnormal autonomic function tests (AFT)] and (1) P-wave duration (p?=?0.008), (2) PR- interval (p?=?0.013). Significant association was found between the number of abnormal AFT and (1) presence of Q-waves, and (2) degree of anaemia (haematocrit class).

Conclusion

Electrocardiographic features consistent with atrio-ventricular and ventricular repolarization abnormalities are associated with CAN in sickle cell anaemia. Further studies are required to evaluate the prognostic implications of these findings in sickle cell patients with cardiovascular autonomic dysfunction.     

Assessing Quality Of Life In Diabetic Neuropathy: Condition‐Specific Or Generic Approach?

Studies that assessed Quality of Life (QoL) in patients with diabetic peripheral neuropathy (DPN) used generic measures, focusing on extremes of DPN. This study compared the performance of the neuropathy-specific QoL measure (NeuroQoL) with the generic SF36, in diabetic patients with varying severity of DPN. 120 DPN patients were included, mean age 61 years, diabetes duration 12 years. DPN severity was assessed by neuropathy disability score (NDS) and vibration perception threshold (VPT): symptom severity by neuropathy symptom score (NSS). All NeuroQoL domains showed significant differences (eg., social; interpersonal relationships p < 0.01) between patients subdivided into those with moderate/severe symptoms (NSS > =6) compared to those with mild (NSS < 6), in contrast to only 2 SF36 domains (mental health; bodily pain p < 0.05). Similarly, when patients were subdivided according to DPN severity (moderate/severe: VPT > =25 and NDS > =6; mild: VPT < 25; NDS < 6), NeuroQoL domains (eg., negative symptoms; sexual problems p < 0.05) demonstrated differences between the groups whereas virtually no differences were seen in SF36. Furthermore, NeuroQoL maintained its ability to differentiate between those with mild (VPT < 25); moderate (VPT:25 to 35) and severe (VPT > 35) DPN, whereas SF36's discriminatory power was lost. All significant differences remained after accounting for confounding variables. Thus, NeuroQoL detects more subtle differences between DPN patients and should therefore be more sensitive to change over time than the SF36.     

2型糖尿病并发糖尿病周围神经病变与代谢综合征的关系

目的 探讨2型糖尿病(T2DM)并发糖尿病周围神经病变(DPN)与代谢综合征(MS)的关系。方法 选取我院收治的T2DM患者95例,按是否并发MS进行分组,并发MS 45例为研究组,无MS为对照组50例。2组均进行电生理检查、MS相关指标的血液、尿液标本测定,统计2组DPN发生率,比较2组SCV和MCV及MS相关指标水平,并进行影响DPN的多因素Logistic回归分析。结果 研究组DPN发生率为62.22%,对照组为12.00%,差异有统计学意义(P0.01)。2组左右腓神经SCV、MCV比较有显著差异(P0.01)。2组TC、TG、LDL-C比较差异无统计学意义(P0.05),2hINS、UA、HbA1c、CRP、UAER水平比较有明显差异(P0.01)。多因素Logistic回归分析结果显示,HbA1c、UAER、2hINS、CRP等MS相关指标异常均为DPN的危险因素。结论 T2DM并发DPN与MS密切相关,MS相关指标,如HbA1c、UAER、2hINS等水平过高是导致DPN发生的高危因素,故临床在控制血糖的时候应注重患者MS相关指标的检测与调控。     

Can both normal and mildly abnormal albuminuria and glomerular filtration rate be a danger signal for diabetic peripheral neuropathy in type 2 diabetes mellitus?

We aimed to investigate the potential association between urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) and diabetic peripheral neuropathy (DPN). We were especially interested in the relationship between normal or mildly abnormal UACR and eGFR with DPN. A retrospective study was performed in 1059 patients with type 2 diabetes patients from Fuzhou, China, who were seen between 2010 and 2015. The DPN population demonstrated higher UACR and lower eGFR than the non-DPN population. Nerve conduction velocities (NCVs) were negatively correlated with UACR and were positively correlated with eGFR. UACR and eGFR were associated with the risk of DPN. Even in the UACR < 30 mg/g and eGFR ≥ 60 ml/min/1.73 m² groups, the relationship above still existed and patients in the highest tertiles of UACR and lowest tertiles of eGFR demonstrated a greater risk of DPN (OR = 2.456, 95% CI 1.461–4.127; OR = 2.021, 95% CI 1.276–3.203). Receiver operating characteristic (ROC) analysis revealed that the area under curve (AUC) of UACR, eGFR, and joints indicates that DPN was 0.749, 0.662, and 0.731, respectively. Lower eGFR and higher UACR may be associated with the risk of DPN, even though normal or mildly abnormal UACR and eGFR have already been found to be predictive factors of DPN. Further, UACR is more sensitive than eGFR. Separately, UACR was a moderate indication of DPN, and combining it with eGFR did not increase its effect of indication to DPN.     

Diagnosis and management of diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is one of the most commonly occurring major complications of diabetes. The disease may manifest in several clinical patterns: most frequently as distal symmetrical sensory polyneuropathy. Guidelines are available for the diagnosis of DPN by the primary care physician. These recommend that a review of diabetic patients, including a questionnaire and inspection and neurological examination of the feet, is undertaken annually. Techniques used for studying the disease process in clinical trials may include nerve conduction and quantitative sensory function tests, autonomic nervous system testing, post-ganglionic sudomotor function and skin biopsy. Current therapies for managing DPN are strict glycaemic control, palliative treatments and foot ulcer prevention. Future treatments aim to beneficially affect the underlying disease pathology and putative agents are currently being investigated.     

Comparison of SSR and QSART in early diabetic neuropathy--the value of length-dependent pattern in QSART

We evaluated postganglionic sympathetic function using the sympathetic skin response (SSR) and quantitative sudomotor axon reflex test (QSART) on the feet of 31 patients with early diabetic neuropathy and 20 age-matched normal controls. The amplitude of SSR and the sweat volume of QSART were significantly decreased in the diabetic patients. We evaluated the sensitivity of the tests in detecting autonomic failure. Out of 31 patients, 14 (45%) had abnormal SSR (14 absent; 17 present), while 16 of 31 patients (52%) had abnormal QSART (1 absent; 5 absolutely reduced and 10 showed a length-dependent pattern of reduction). More important than differences in sensitivity is the specificity of QSART, which specifically evaluates the postganglionic axon (instead of polysynaptic pathways in SSR) and provides quantitative data on the severity and pattern of autonomic deficit. In normal controls under 65 years of age, there was a significant correlation between the amplitude of SSR and the sweat volume of QSART. However, there was no significant relationship between these in diabetic patients. These results suggest that QSART can evaluate early diabetic neuropathy more precisely than SSR.     

高频超声、神经电生理对糖尿病性周围神经病的手术评估

目的 探讨高频超声、神经电生理在糖尿病性周围神经病(DPN)早期诊断及其神经减压手术时机、疗效评估中的应用价值.方法 对560例糖尿病性下肢周围神经病患者,按Dellon术式对卡压神经进行显微松解术.所有病例术前、术后1.5年进行多伦多临床神经病变评分(TCSS),神经高频超声、定量感觉功能(QST)、神经感觉传导速度(NCV)检测,并在相应时间节点采用同样指标与健康对照组进行对比.结果 DPN患者高频超声显示受累神经肿胀、增粗,内部回声减低,神经内线状结构消失,神经前后径(D1)和横径(D2),横断面积(CSA)手术前后差异有统计学意义(P＜0.01).NCV阳性检测率为74.9%,QST阳性检测率为90.9%,两者差异有统计学意义.DPN早期诊断QST较NCV更为敏感.NCV术后较术前明显增快(P＜0.05),冷感觉阈值较术前明显升高(P＜0.05);热感觉阈值较术前明显降低(P＜0.01);振动觉阈值较术前明显降低(P＜0.05).NCV与冷感觉阈值呈正相关;与热感觉阈值、振动觉阈值呈负相关.术前TCSS评分19分者术后75%改善至10～13分(P＜0.01).结论 高频超声能够从形态学角度提供神经卡压程度、部位等信息.QST检测适用于DPN的早期诊断,QST异常是实施下肢神经减压术的适应证.QST与NCV两者联合使用对把握手术时机具有重要意义,高频超声、NCV、QST可作为评价手术疗效的客观依据.     

Association of electrochemical skin conductance with neuropathy in chemotherapy-treated patients

Purpose

Chemotherapy-induced peripheral neuropathy (CIPN) is an adverse event of cancer treatment that can affect sensory, motor, or autonomic nerves. Assessment of autonomic neuropathy is challenging, with limited available tools. Accordingly, it is not routinely assessed in chemotherapy-treated patients. In this study, we aimed to examine whether electrochemical skin conductance (ESC) via Sudoscan, a potential measure of autonomic function, associates with subjective and objective measures of CIPN severity and autonomic neuropathy.

Methods

A cross-sectional assessment of patients who completed neurotoxic chemotherapy 3–24 months prior was undertaken using CIPN patient-reported outcomes (EORTC-QLQ-CIPN20), clinically graded scale (NCI-CTCAE), neurological examination score (TNSc), autonomic outcome measure (SAS), and Sudoscan. Differences in CIPN severity between participants with or without ESC dysfunction were investigated. Linear regression analyses were used to identify whether ESC values could predict CIPN severity.

Results

A total of 130 participants were assessed, with 93 participants classified with CIPN according to the clinically graded scale (NCI-CTCAE/grade ≥ 1), while 49% demonstrated hands or feet ESC dysfunction (n = 46). Participants with ESC dysfunction did not significantly differ from those with no dysfunction on multiple CIPN severity measures (clinical-grade, patient-report, neurological examination), and no differences on the autonomic outcome measure (SAS) (all p > 0.0063). Linear regression analyses showed that CIPN could not be predicted by ESC values.

Conclusions

The inability of ESC values via Sudoscan to predict clinically-graded and patient-reported CIPN or autonomic dysfunction questions its clinical utility for chemotherapy-treated patients. The understanding of autonomic neuropathy with chemotherapy treatment remains limited and must be addressed to improve quality of life in cancer survivors.

     

Reduced skeletal muscle quantity and quality in patients with diabetic polyneuropathy assessed by magnetic resonance imaging

Introduction: The aim of this study was to determine whether diabetic polyneuropathy (DPN) is associated with reduced muscle quality using MRI. Methods: MRIs of the tibialis anterior (TA) muscle were recorded from 9 individuals (5 men) with DPN (～65 years) and 8 (4 men) age‐ and gender‐matched controls. A magnetization transfer ratio (MTR) and T2 relaxation times of the TA were calculated. Results: Despite equal voluntary activation, the DPN group was ～37% weaker than controls, with a significantly lower proportion (～8%) of contractile tissue and lower MTR (0.28 ± 0.03 vs. 0.32 ± 0.02 percent units). T2 relaxation time was significantly longer in the DPN group (77 ± 16 ms) compared with controls (63 ± 6 ms). Conclusions: These findings indicate a reduction in the structural integrity and myocellular protein density in the TA of those with DPN. Thus, muscle weakness in DPN is likely due to both a loss of muscle mass and a reduction in contractile quality. Muscle Nerve 53 : 726–732, 2016     

The utility of a point-of-care sural nerve conduction device for detection of diabetic polyneuropathy: A cross-sectional study

Introduction: Rapid and accessible methods for diagnosing diabetic polyneuropathy (DPN) have been developed, but not validated, in large cohorts of people with diabetes. Methods: The performance of a point-of-care device (POCD) was studied in 168 patients with type 2 diabetes, estimating the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) compared with conventional sural nerve conduction studies (NCS). Results: A POCD amplitude limit of 6 µV increased the sensitivity (96%) and NPV (98%), but decreased the specificity (71%) and PPV (54%) compared with the 4-µV limit, which had values of 78%, 92%, 89%, and 71%, respectively. POCD on both legs showed better performance than on 1 leg. POCD amplitudes and conduction velocities correlated significantly with conventional sural NCS, but POCD values were underestimated compared with NCS. Discussion: The POCD may be used as a suitable screening tool for detection of DPN. Patients with abnormal and borderline results should undergo conventional NCS. Muscle Nerve 59 :187–193, 2019