Role of Blink Reflex in diagnosis of subclinical cranial neuropathy in Diabetic Mellitus type II

BACKGROUND AND OBJECTIVES: Peripheral Neuropathy (PN) is one of the late complications of Diabetes Mellitus. Cranial nerves III, VII and V are among the most commonly affected in diabetic patients. Traditional Electrodiagnosis (Edx) studies are useful method for diagnosis of PN and symptomatic cranial neuropathy, and may not be useful for detecting subclinical involvement of cranial nerves. The main objective of this study is to evaluate the role of Blink Reflex (BR) for early diagnosis of cranial neuropathy in diabetic patients with PN. DESIGN: A prospective study was performed on NIDDM patients with a PN. 188 subjects were included in our study in which 142 acted as healthy subjects and 46 as diabetic patients. Patients were excluded with prior history of cranial nerve lesions, stroke, and other disease with polyneuropathy or drug-induced neuropathy. Routine nerve conduction studies were performed and only patients with PN were included in this study. RESULTS: Abnormalities were found in 54.4% of patients. R1, IR2 and CR2 were prolonged relative to healthy group. Statistically there was no significant difference in R/D ratio of patients (P = 0.201). Also there was a positive correlation between R1, IR2 and CR2 latencies with duration of diabetes and severity of polyneuropathy, but not for R/D. The greatest correlation was shown in R1 latency (69.9% abnormality). CONCLUSION: BR is a non-invasive and very useful method for evaluation and diagnosis of subclinical cranial nerve involvement in diabetic patients.     

Electrophysiological findings of acute peripheral facial palsy in diabetic and non-diabetic patients

The aim of this study is to investigate the role of diabetes mellitus on the clinical and electrophysiological findings of peripheral facial palsy (PFP), the effect of the diabetes duration and polyneuropathy on the electrophysiological parameters. A total of 32 diabetic and 40 non-diabetic patients with peripheral facial palsy were included. All patients were divided into two subgroups based on the time of electrophysiological examinations: within the first 15 days versus within 16–30 days. Neuropathy symptoms and the results of neurological examinations and electrophysiological findings were recorded. The findings of electroneurography (EnoG), blink reflex (BR) evaluation, and needle electromyography (EMG) indicated statistically significant blink reflex abnormalities in diabetic patients compared to non-diabetics. Delay in the latency was more remarkable in the R2 component than in the R1 (p < 0.001). The delay in the R1 latency was also observed in the non-affected side for diabetic patients. The longer duration of the diabetes caused significant delay on the blink reflex latency on both the affected and non-affected sides for R1 component (p = 0.019, p = 0.041, respectively). In contrary, neither the diabetes duration nor the age of the patients correlated with the clinical severity of facial palsy, fiber loss, fibular nerve compound muscle action potential amplitudes, and the nerve conduction velocities.     

瞬目反射的临床应用研究

本文对26例无脑部病变患者及26例脑部病变的患者分别作了瞬目反射(BlinkReflex BR)的检测。刺激一侧眶上神经,于两侧下眼轮匝肌记录。同侧的两个波为R_1、R_2,对侧的一个波为R′_2。结果脑部病变组双侧R_1、R_2、R_2潜伏期与无脑部病变组比较P值<0.01,有非常显著性差异。提示BR可帮助临床上了解三叉神经、面神经、脑干、丘脑或皮层的机能,可了解病变范围和异常程度,有助于临床定位诊断及药物疗效观察。     

The cutaneous silent period in diabetes mellitus

The cutaneous silent period (CSP) may be useful as a method for the evaluation of smaller and unmyelinated fiber dysfunctions. CSP refers to the brief interruption in voluntary contraction that follows strong electrical stimulation of a cutaneous nerve. The aim the present study is to establish whether CSP can be instrumental in the determination of diabetic neuropathy. The nerve conduction studies and CSP evaluations were both used in patients with Diabetes Mellitus and control group. All patients were given clinical neurological examinations for the determination of small-fiber neuropathy (SFN). The CSP values for patients with SFN were compared with values of those without SFN. The nerve conduction velocities had changed unfavorably in diabetic patients. No median nerve CSP reponse could be obtained in two of the diabetic patients. CSP latency (84.6+/-14.0) in diabetics was longer than controls (76.2+/-13.1) (p=0.018). The duration of CSP was similar for the two groups (p=0.46). The CSP latency showed a correlation with routine nerve conduction studies. While the CSP latencies (86.7+/-15.8) of patients who were clinically diagnosed with SFN were similar to the latencies (81.3+/-10.4) of patients without SFN (p=0.606), the duration of CSP (44.6+/-13.7) in patients with SFN was shorter than the duration (55.3+/-12.2) in patients without SFN (p=0.012). These results indicate that even though the CSP does not provide any advantage over routine electrodiagnostic studies in determining diabetic neuropathy, still it may be a useful method for the early detection of diabetic SFN.     

正常学龄儿童瞬目反射的初步研究

应用电刺激法研究４０例正常学龄儿童的瞬目反射。通常能诱发出刺激侧快反应（Ｒ１）、迟反应（Ｒ２）及对侧迟反应（Ｒ２＇）。分析Ｒ１的形态、各波的潜伏期、时程、波幅，制定出正常值。瞬目反对的检查结果可作为诊断多种脑干障碍和三叉神经、面神经病变的方法。     

神经传导速度早期诊断糖尿病性周围神经病

本文对58例糖尿病人进行了神经传导速度(NCV)测定,其中有周围神经损害的症状和体征,临床诊断为糖尿病并发周围神经病者32例,临床无周围神经损害的糖尿病者26例。其结果表明,NCV测定为判断周围神经损害的一种客观指标,且感觉神经测定比运动神经敏感,下肢胫神经测定比上肢敏感,也可提示亚临床期的周围神经病变,有助于糖尿病性周围神经病的早期诊断。     

The usefulness of the brainstem auditory evoked potential in the early diagnosis of cranial nerve neuropathy associated with diabetes mellitus

BACKGROUND: An evaluation of the extent and mechanism of damage of the central nervous system in diabetes mellitus is of high value in current neurological research. Electrophysiological abnormalities are frequently present is completely asymatomatic diabetes mellitus (DM) patients. Limited data is available in the use of brainstem auditory evoked potential (BAEP) in DM. AIM: Is to evaluate the efficacy of BAEP as a method useful in the diagnosis of subclinical damage of the central nervous system in DM. MATERIAL AND METHOD: 67 diabetes and 32 healthy controls - age and sex matched - were chosen. The diabetes were of type I and II and more than or less than 10 years duration. The BAEP was elicited by using auditory stimulus by using Dantec Evomatic 4000 evoked potential machine. The latency of component response recored as waves I, III and V, interpeak latency (IPLs) I - III, I - V, III - V and amplitude of waves V. RESULTS: The difference was highly significant in the increased latency of waves I, III and V, interpeak latency (IPLs) I - III, I - V, III - V and amplitude of waves V of each type of diabetes as compared to control. Comparison of the type and duration of diabetes between each other showed no significant difference. CONCLUSION: BAEP recording can represent an objective, clinically useful and non invasive procedure to stress the early impairment both of the auditory nerve and of brainstem function.     

Sympathetic skin response in diabetic neuropathy

Autonomic neuropathy is a complication of diabetes mellitus (DM) in substantial proportion of cases and may cause definite autonomic symptoms. Because conventional electrophysiological methods do not assess the autonomic nervous system, simple reproducible tests were developed. One of them is sympathetic skin response (SSR) which provides useful information about the status of sympathetic postganglionic function. The aim of this study is to perform SSR in diabetic patients to see whether this test can be used as an electrophysiological method for the diagnosis and confirmation of diabetic autonomic neuropathy. 20 diabetic patients who had electrophysiologically confirmed polyneuropathy but showed no symptoms or signs referable to autonomic system dysfunction were included. 14 (70%) patients demonstrated abnormal SSR. 2 abnormal patterns were observed. An absent response in at least one tested lower extremity (50%) and prolonged foot with normal hand latency (20%). 6 patients (30%) demonstrated no abnormalities. Foot and hand latencies in diabetics did not differ significantly from those of normal controls (p: 0.4, p: 0.1) and no correlation could be found with latencies and duration of sickness, patient's age and HbA1c values. We believe latency measurement is an objective measure of conduction in multineural pathways and can detect subclinical involvement of sympathetic nervous system in diabetics who do not manifest symptoms or signs referable to autonomic system dysfunction.     

Clinical usefulness of the two-site Semmes-Weinstein monofilament test for detecting diabetic peripheral neuropathy

The present study was done to validate the two-site Semmes-Weinstein (SW) monofilament test in identifying patients at risk of lower-extremity complications in clinical setting. The SW monofilament test and nerve conduction study were conducted on type 2 diabetic patients (n=37) at Pusan National University Hospital in Korea. As the duration of diabetes mellitus was longer, neuropathy identified by nerve conduction study and complications of diabetes were more severe (p<0.01). The number of sites unable to perceive SW monofilament (p<0.001) was larger in patients with lower-extremity neuropathy symptoms than those without symptoms. Sensitivity and specificity at two sites (the third and fifth metatarsal head sites) were 93% and 100%, respectively. In conclusion, the two-site SW monofilament test was a sensitive, specific, simple, and inexpensive screening tool for identifying diabetic peripheral neuropathy in clinical setting.     

面瘫患者面神经电图和瞬目反射的应用比较

目的:比较面瘫患者瞬目反射和面神经电图的应用价值。方法:这些面瘫患者经过四周基础治疗和(或)针灸治疗后,进行健、患侧瞬目反射(207例)和面神经电图(205例)检查比较。结果:瞬目反射治疗前健、患侧R1值的差异有极显著意义(P<0．01);治疗后健、患侧R1值的差异无显著意义 (P>0．05)。面神经电图患侧潜伏期延长者于治疗后均有所好转(P<0．05),波幅降低者治疗后无明显改善(P>0．05)。结论:面瘫患者治疗后瞬目反射改善非常明显,而面神经电图恢复存在明显的滞后现象,早期诊断(发病第一周)瞬目反射检查优于面神经电图,中后期面神经电图检查优于瞬目反射。     

判别分析方法在糖尿病周围神经病变早期诊断中的应用

目的:探讨体征检查和电生理检查诊断糖尿病周围神经病变(diabetic peripleral neuropathy,DPN)的一致性,进而寻找适合DPN早期诊断指标.方法:通过自行开发的神经传导检测仪采集60例糖尿病病人和20例正常人的神经传导数据进行病例-对照分析,用判别分析方法验证神经传导各参数与临床体征判别分组的符合率.结果:神经传导检测与临床体征诊断DPN基本一致,腓肠感觉神经传导速度和腓总神经F波潜伏期对早期DPN诊断灵敏度较高.结论:将判别分析方法用于DPN早期诊断,可有效提高早期病变诊出率.     

Lowered response threshold and increased responsiveness to mechanical stimulation of cutaneous nociceptive fibers in streptozotocin-diabetic rat skin in vitro--correlates of mechanical allodynia and hyperalgesia observed in the early stage of diabetes

Rats rendered diabetic by streptozotocin (STZ) show allodynia and hyperalgesia and thus, have been offered as a model of pain in diabetic neuropathy. However, recent electrophysiological studies on these rats found that C-fiber nociceptors were not consistently hyperexcitable to mechanical stimulations by von Frey hairs and that there was no change in their response thresholds. In the present study, we used rat skin-saphenous nerve in vitro preparations, in which the receptive fields of identified single C-polymodal receptors (CPRs) can be accurately stimulated with a servo-controlled mechanical stimulator. Single fiber recordings from CPRs were performed in diabetic rats with an increased behavioral nociceptive response 7-19 days after STZ injection. The proportion of units with spontaneous activity and the magnitude of this activity increased in the diabetic preparations. The response thresholds of CPRs were significantly decreased with ramp-pressure stimulation and their response magnitude to the suprathreshold stimulation was significantly increased in diabetic rats. In addition, the response pattern to mechanical stimulation was also changed to a non-adapting type. These findings suggest that changes in CPRs contribute to the enhanced nociception observed in the early stage of diabetic neuropathy.     

2型糖尿病周围神经病变与血清促甲状腺激素关系的研究

目的 分析2型糖尿病（T2DM）患者周围神经病变与血清促甲状腺激素（TSH）水平的关系。方法 选择329例柳州市人民医院内分泌科住院T2DM患者进行横断面研究,按照有无神经病变分为糖尿病周围神经病变（DPN）组193例和无糖尿病周围神经病变（NDPN）组136例。收集所有患者临床资料,检测两组患者HbAlc、TC、TG、HDL-C、LDL-C、TSH水平。结果 两组HbAlc、TC、HDL-C、LDL-C、TSH组间比较,差异无统计学意义（P＞0.05）;DPN组年龄大于NDPN组,糖尿病病程长于NDPN组,统计学意义显著（P＜0.01）;DPN组TG水平低于NDPN组,差异有统计学意义（P＜0.05）。Logistic回归分析发现,HbA1c、病程及年龄进入最终回归方程[OR=1.170,95%CI:1.048~1.305（HbA1c）;OR=1.059,95%CI:1.013~1.108（病程）;OR=1.043,95%CI:1.015~1.072（年龄）],HbA1c、病程及年龄是DPN发生的危险因素。结论 HbA1c、病程及年龄是DPN发生的危险因素,住院T2DM患者DPN与血清TSH水平无明显相关。     

神经传导速度对糖尿病周围神经病的诊断价值

目的 :探讨神经传导速度 (NCV)对糖尿病周围神经病 (DPN)的诊断价值。方法 :对 5 0例糖尿病患者分为有症状组和无症状组 ,进行周围神经NCV的测定 ,与健康人对照 ,同时行相关因素分析。结果 :糖尿病患者运动神经传导速度 (MCV)、感觉神经传导速度 (SCV)与健康人比较存在明显差异 ,且有症状组更显著 (P <0 0 5 ) ;患者的NCV与空腹血糖无明显相关 ,而与病程长短呈正相关。结论 :周围神经NCV的检测有助于DPN的早期诊断     

Prevalence and risk factors for severity of diabetic neuropathy in type 2 diabetes mellitus

Purpose: To estimate the prevalence of diabetic neuropathy (severity wise) and associated risk factors in a population having type 2 diabetes mellitus. Materials and Methods: A population-based sample of 1401 persons with diabetes (identified as per the WHO criteria) underwent comprehensive eye examination including stereoscopic digital photography (45° four field) for diabetic retinopathy grading. Vibration perception threshold (VPT) measurements were done to assess neuropathy (cut off ≥ 20 V). Severity of neuropathy was graded into three groups based on VPT score as mild (20-24.99 V), moderate (25-38.99 V), and severe (≥39 V). Univariate and multivariate analyses were done to find out the independent risk factors for severity of diabetic neuropathy. Results: In the overall group, the prevalence of diabetic neuropathy was 18.84% (95% CI: 16.79-20.88). The prevalence of mild diabetic neuropathy was 5.9% (95% CI: 4.68-7.15), moderate diabetic neuropathy was 7.9% (95% CI: 6.50-9.33), and severe diabetic neuropathy was 5% (95% CI: 3.86-6.14). Increasing age per year (P < 0.0001) was a statistically significant risk factor for all - mild, moderate, and severe - types of diabetic neuropathy. For severe diabetic neuropathy, other significant risk factors were duration of diabetes mellitus (P = 0.027), macroalbuminuria (P = 0.001), and presence of diabetic retinopathy (P = 0.020). Conclusions: The results suggested that every fifth individual in a population of type 2 diabetes is likely to have diabetic neuropathy. Nearly 13% had neuropathy of moderate and severe category, making this group vulnerable for complications such as foot ulceration or lower limb amputation.     

Epidermal nerve fiber quantification in the assessment of diabetic neuropathy

Assessment of cutaneous innervation in skin biopsies is emerging as a valuable means of both diagnosing and staging diabetic neuropathy. Immunolabeling, using antibodies to neuronal proteins such as protein gene product 9.5, allows for the visualization and quantification of intraepidermal nerve fibers. Multiple studies have shown reductions in intraepidermal nerve fiber density in skin biopsies from patients with both type 1 and type 2 diabetes. More recent studies have focused on correlating these changes with other measures of diabetic neuropathy. A loss of epidermal innervation similar to that observed in diabetic patients has been observed in rodent models of both type 1 and type 2 diabetes and several therapeutics have been reported to prevent reductions in intraepidermal nerve fiber density in these models. This review discusses the current literature describing diabetes-induced changes in cutaneous innervation in both human and animal models of diabetic neuropathy.     

Corneal reflex and blink reflex changes in thalamic hemorrhage

We studied the corneal reflex (CR) with air-puff and direct touch by using a standardized method in patients with thalamic hemorrhage (TH) (n: 15) and in normal control subjects (n: 21). The conventional blink reflex (BR) was also studied. In the TH group: 1--When the cornea on the clinically nonaffected side was stimulated the corneal reflex responses were elicited bilaterally, with normal latency on the clinically normal side and delayed on the affected side. 2--When the cornea on the clinically affected side was stimulated, the corneal responses on both sides were either abnormal or could not be elicited. 3--The ipsilateral R1 and R2 responses recorded by stimulation of the supraorbital nerve on the clinically affected side were abnormal where the contralateral R2 responses were in the normal range. In the normal control and TH groups: 1--No statistical difference could be detected between the responses elicited by air-puff or direct touch to cornea (p > 0.05). 2--CR responses were statistically different from the R2 response of the BR (p < 0.005).     

Peripheral neuropathy in patients with diabetes mellitus presenting as Bell's palsy

The aim of this study is to evaluate the peripheral nerves in diabetes mellitus with or without peripheral facial paralysis (PFP). A total of 49 diabetic patients with PFP within the last year (23 females, mean age 60.3 +/- 9.3), and 83 diabetic patients without PFP (41 females, mean age 59.5 +/- 9.9) were enrolled. The neurological examination, eye-blinking response, needle EMG and electrophysiological parameters of peripheral nerves were evaluated. The neuropathic pain, other positive and negative sensory symptoms were statistically more frequent in controls than the PFP group, while no difference was noted in total neuropathy score. Sural sensorial nerve action potential amplitudes were same in both groups, but median nerve amplitudes were significantly lower in the PFP group. It is suggested that PFP is not a part of multifocal neuropathy in diabetes mellitus. However, at least some parts of the nerve conduction studies were involved, focal neuropathies were more frequent while sensory neuropathies with small nerve fiber involvement were less frequent in diabetes patients with PFP.     

The palmomental reflex from mechanical stimulation in normal man: normative data

The authors report normative data on the electrical response (EMG response) recorded from the mentoneal muscles by repetitive mechanical stimulation of the palmar and dorsal surface of the hand in 23 normal adults: the palmomental reflex (PMR). An early and late response was observed in 11 cases. The PMR potentials showed great variability in latency, amplitude and duration and were present in about 70% of the subjects in whom the PMR was undetectable by visual inspection. In 3 cases the reflex was also observed contralaterally to the side of stimulation. The afferent branch of the normal PMR is constituted of impulses originating mainly from the median nerve skin and muscle receptors. Such impulses could reach facial motor nuclei either through short-(paucisynaptic) or long-loop (thalamocortical) circuits.     

Auditory neuropathy in streptozotocin-induced diabetic mouse

An investigation of the mechanism of damage to the peripheral nervous system and central nervous system in diabetes mellitus (DM) is highly important in current neurological research. Auditory neuropathy is a hearing disorder in which the auditory brainstem evoked potential is absent or severely abnormal. This study investigated auditory neuropathy caused by streptozotocin in mouse model. In order to assess diabetic auditory neuropathy, we evaluated auditory brainstem response (ABR) for the evaluation of sensorineural function in peripheral auditory nerve. Auditory middle latency response (AMLR) was employed to assess the middle response in the midbrain. STZ groups significantly increased the absolute latencies IV and the interpeak latencies I-III and I-IV of ABR compared with STZ 0 group. Pa latency of AMLR also significantly increased in proportion to STZ dosage. Taken together, our results demonstrate that STZ-induced DM may impair the auditory pathway from peripheral auditory nerve to midbrain in the mouse model. We suggest that the STZ-induced diabetic mouse model may be useful for the evaluation of auditory pathway impairment by using ABR and AMLR tests.