Neuropathies in children and adolescents with diabetes: the tip of the iceberg

Assessment of nerve conduction studies in insulin-dependent diabetes in children and adolescents at the tertiary care center in eastern Nepal

Background

Young adults suffering from Type 1 Diabetes mellitus may have diabetic peripheral neuropathy without any signs and symptoms, as one of the complications. Nerve conduction study is routinely used for evaluation of neuromuscular function. This study aimed to conduct a nerve conduction study in insulin-dependent type 1 diabetes mellitus in children and adolescents.

Methods

It was a cross-sectional, descriptive study conducted on 16 diagnosed cases of diabetes mellitus in children aged between 5-15 years and 16 healthy controls. Children were selected based on inclusion criteria from Pediatric and adolescent diabetic clinics who came for follow-up. A motor nerve conduction study of the median, tibial, and common peroneal nerves was recorded, and a sensory nerve conduction study of the median and sural nerves was recorded.

Results

The percentage of females was 46.4% and males were 53.6%. The age of diabetic children was (mean ± SD) 9.75 ± 3.53 and healthy control was 10.75 ± 3.14. A comparison of sensory nerve conduction parameters between type one diabetes in children and healthy control; onset latency of the sural nerve was prolonged on the bilateral side in diabetes children. Similarly, the SNAP amplitude of the median and sural nerves was decreased in diabetes children.

Conclusions

In type 1 diabetes in children, peripheral nerves get affected even in asymptomatic patients in children. More disease duration and uncontrolled glucose levels will lead to the involvement of nerves getting affected. Proper follow-up is needed for better management.

Corneal Confocal Microscopy Abnormalities in Children and Adolescents With Type 1 Diabetes

OBJECTIVE

Utility of corneal confocal microscopy (CCM) in children and adolescents with type 1 diabetes mellitus (T1DM) without neuropathic symptoms or signs and minimal abnormality in large and small nerve fiber function tests remains largely undetermined. This study aimed to evaluate the performance of CCM in comparison to thermal detection thresholds (TDT) testing and nerve conduction studies (NCS) for detecting neuropathy in children with T1DM.

METHODS

A cohort of children and adolescents with T1DM (n = 51) and healthy controls (n = 50) underwent evaluation for symptoms and signs of neurological deficits, including warm detection threshold, cold detection threshold, vibration perception threshold, NCS, and CCM.

RESULTS

Children with T1DM had no or very minimal neuropathic symptoms and deficits based on the Toronto Clinical Neuropathy Score, yet NCS abnormalities were present in 18 (35%), small fiber dysfunction defined by an abnormal TDT was found in 13 (25.5%) and CCM abnormalities were present in 25 (49%). CCM was abnormal in a majority of T1DM children with abnormal TDT (12/13, 92%) and abnormal NCS (16/18, 88%). CCM additionally was able to detect small fiber abnormalities in 13/38 (34%) in T1DM with a normal TDT and in 9/33 (27%) with normal NCS.

CONCLUSION

CCM was able to detect corneal nerve loss in children with and without abnormalities in TDT and NCS.

Point Prevalence of Peripheral Neuropathy in Children and Adolescents with Type 1 Diabetes Mellitus

OBJECTIVE

To assess the point prevalence of peripheral neuropathy (PN) in children with type 1 diabetes mellitus (T1DM) and to determine their predictors.

METHODS

In this cross-sectional study, children aged 8-18 y with T1DM on insulin therapy for > 2 y and free from acute complications were enrolled. All participants were evaluated for symptoms of PN with diabetic neuropathy symptom (DNS) score and underwent a detailed neurological examination. Assessment of nerve dysfunction was done using nerve conduction studies (NCS). The disease-related factors that increase the risk of PN were determined.

RESULTS

Fifty children (52% boys) were enrolled with mean age of 12.2 ± 2.8 y and duration of diabetes 5.1 ± 2.1 y. No subject had clinical evidence or DNS score suggestive of PN. Twenty-eight (56%) children demonstrated subclinical neuropathy on NCS. Proportion of children with pure motor, pure sensory, and mixed motor-sensory neuropathy was 40%, 2%, and 14%, respectively. The peroneal nerve was the most common motor nerve affected. Poor glycemic control (HbA1c > 9%) and longer duration of diabetes (> 5 y) were significantly associated with the risk of PN (p value < 0.05).

CONCLUSION

A large proportion of children with T1DM have subclinical PN. Poor glycemic control and longer duration of diabetes are risk factors for nerve dysfunction. Neurophysiological studies should be performed in these children to facilitate early detection.

Diabetic neuropathy in children and youth: New and emerging risk factors

Pediatric neuropathy attributed to metabolic dysfunction is a well-known complication in children and youth with type 1 diabetes. Moreover, the rise of obesity and in particular of type 2 diabetes may cause an uptick in pediatric neuropathy incidence. However, despite the anticipated increase in neuropathy incidence, pathogenic insights and strategies to prevent or manage neuropathy in the setting of diabetes and obesity in children and youth remain unknown. Data from adult studies and available youth cohort studies are providing an initial understanding of potential diagnostic, management, and preventative measures in early life. This review discusses the current state of knowledge emanating from these efforts, with particular emphasis on the prevalence, clinical presentation, diagnostic approaches and considerations, and risk factors of neuropathy in type 1 and type 2 diabetes in children and youth. Also highlighted are current management strategies and recommendations for neuropathy in children and youth with diabetes. This knowledge, along with continued and sustained emphasis on identifying and eliminating modifiable risk factors, completing randomized controlled trials to assess effectiveness of strategies like weight loss and exercise, and enhancing awareness to support early detection and prevention, are pertinent to addressing the rising incidence of neuropathy associated with diabetes and obesity in children and youth.

Prevalence of peripheral neuropathy in patients with diabetes: A systematic review and meta-analysis

AIMS

We aimed to determine pooled prevalence of diabetic peripheral neuropathy (DPN) in patients with diabetes and to explore the impacts of research variables on prevalence estimates.

METHODS

A systematic search was performed in PubMed, EMBASE, The Cochrane Library and Scopus from onset up to July 2018 to identify articles investigating the prevalence of DPN. Random-effects models were used to calculate the pooled prevalence of DPN. The heterogeneity of the study was estimated with the I² statistic. The publication bias was described by Egger's test and funnel plot.

RESULTS

A total of 29 studies with a total of 50,112 participants were included in this meta-analysis. The results showed that the pooled prevalence of DPN was 30% (95% confidence interval, CI 25-34%). The pooled prevalence of DPN among patients with type 2 diabetes mellitus was higher than patients with type 1 diabetes mellitus (31.5%, 95% CI 24.4-38.6% vs 17.5%, 95% CI 4.8-30.2%). The pooled prevalence of DPN of studies involving a mixed type of diabetes mellitus was 24.8% (95% CI 13.1-36.5%, I²=99.1%).

CONCLUSIONS

Medical staff should strengthen the evaluation and diagnosis of DPN. Moreover, they need to teach diabetic patients how to prevent this complication.

Electrophysiological Characterization of Neuropathy Complicating Type 1 Diabetes Mellitus

Diabetic peripheral neuropathy (DPN) involves sensory and motor nerves, resulting in demyelination as well as axonal degeneration. This study was conducted to describe the pattern of lower limb nerve involvement in children with type 1 diabetes mellitus (DM) based on the parameters of nerve conduction study (NCS). This cross-sectional study recruited 50 children with type 1 DM having mean disease duration of 4.92 ± 3.84 years who attended the referred clinic in Sudan Childhood Diabetes Center. Their mean age was 15.00 ± 2.19 years, 42% were males, and 58% were females. Twenty six matched healthy control subjects were involved; their mean age was 13.88 ± 2.46 years, 38.46% were males, and 61.54% were females. Bilateral NCS of the sensory and motor lower limb nerves was performed using Medelec Synergy machine. Interpretation of the patients' results was based on our own control reference values. Data was analysed using IBM SPSS statistics. Out of the 50 diabetic patients, 44 (88%) had electrophysiological evidence of peripheral neuropathy (abnormalities in at least two of the electrophysiological parameters). The majority (68.2%) had motor involvement and 31.8% had sensorimotor, while none of them (0%) had pure sensory involvement. Regarding abnormal NCS parameters (conduction velocity vs. amplitude of the compound action potential), conduction slowing feature predominated in 61.4% and only few (6.8%) showed amplitude reduction, while 31.8% showed mixed features. The most frequently affected nerve was the common peroneal, followed by posterior tibial, and the least was the sural nerve. The most sensitive parameter was the common peroneal conduction velocity. Motor precedes sensory nerve involvement. The most frequent neurophysiological abnormality was the conduction slowing, and the common peroneal was the most vulnerable nerve. These findings signify generation of a protocol for early screening of neuropathy in children with type 1 diabetes.

High Prevalence and Incidence of Diabetic Peripheral Neuropathy in Children and Adolescents With Type 1 Diabetes Mellitus: Results From a Five-Year Prospective Cohort Study

BACKGROUND

In this prospective cohort study, we investigated the prevalence of diabetic peripheral neuropathy at baseline and after five years of follow-up in children and adolescents with type 1 diabetes mellitus using both measurements of nerve conduction velocity and clinical neurological examination.

METHODS

A total of 38 patients who underwent insulin pump or intensive insulin therapy were included. The subjects averaged 12.6 ± 2.4 years of age and their diabetes duration averaged 5.6 ± 3.2 years. All patients underwent a detailed physical, neurological, and electrophysiological examination, as well as laboratory testing at their annual checkup.

RESULTS

At baseline, the prevalence of diabetic peripheral neuropathy diagnosed using neurological examination was 13.2%, whereas nerve conduction velocity testing revealed diabetic peripheral neuropathy in 31.6%, highlighting a high prevalence of subclinical diabetic peripheral neuropathy. During follow-up, there was a strong increase in the prevalence of clinically diagnosed diabetic peripheral neuropathy, which reached 34.2% (P = 0.039) after five years; the proportion of patients with subclinical diabetic peripheral neuropathy even reached 63.2% (P = 0.002). The most significant changes in electrophysiological parameters were observed in the tibial sensory nerve (P = 0.001).

CONCLUSIONS

The prevalence of diabetic peripheral neuropathy in children and adolescents with type 1 diabetes mellitus was high, and there was a rapid increase in the prevalence of diabetic peripheral neuropathy during a five-year follow-up interval. Importantly, our data show that a mere clinical evaluation is not sensitive enough to diagnose diabetic peripheral neuropathy in these patients. Nerve conduction velocity measurement, which is regarded as the gold standard for the assessment of diabetic peripheral neuropathy, should be applied more broadly.

Reproducibility of vibration perception threshold values in children and adolescents with type 1 diabetes mellitus and associated factors

AIMS

To define the reproducibility of vibration perception thresholds (VPTs) and the possible associated factors, as an early index of peripheral diabetic neuropathy (PDN) in type 1 diabetes mellitus (T1DM) children and adolescents.

METHODS

A single examiner studied 118 T1DM subjects (aged 13.5±3.4 years) and 79 controls (aged 12.0±3.07 years). Glycaemic control was assessed with HbA1c levels. VPT was measured twice on upper and lower limbs, using a Biothesiometer. Concordance between the two VPT measurements was evaluated using the Cohen's Weighted Kappa statistic (Kappa=0.41-0.60→moderate concordance, Kappa=0.61-0.80→substantial concordance).

RESULTS

T1DM children had significantly higher VPTs than controls at all sites (p=0.001), but with lower Kappa values (0.64-0.70). VPT values increased in parallel with HbA1c (a.<8%, b. 8-9.5%, c.>9.5%) and T1DM duration (a.<5 years, b.5.1-10, c.>10 years). However, Kappa values were lower in the groups with the poorest control (HbA1c>9.5%) (Kappa=0.54-0.76) or the longest T1DM duration (>10 years) (Kappa=0.49-0.71). Although VPTs increased with stature and male gender, no effect on VPT reproducibility was observed. However, obesity was associated with lower VPT values and poorer concordance.

CONCLUSIONS

These findings suggest that the reproducibility of VPTs is lower in the high-risk patients for early subclinical PDN development, who need a regular follow-up.

Decreased excitability of the distal motor nerve of young patients with type 1 diabetes mellitus

OBJECTIVE

The compound muscle action potential (CMAP) scan is a novel neurophysiological technique that appears more sensitive in detecting peripheral motor neuropathy than conventional methods. This study explores the value of the CMAP scan for the detection of subclinical diabetic peripheral motor neuropathy.

METHODS

In this cross-sectional pilot study, CMAP scanning of the peroneal nerve was performed in (i) 13 well-controlled patients (8-25 yr old) with type 1 diabetes mellitus (T1DM) duration between 2.5 and 5 yr; (ii) 17 patients (10-25 yr old) with a duration of T1DM of at least 10 yr, poorly controlled and/or with microvascular complications and (iii) 13 adults with T1DM and established clinical diabetic peripheral neuropathy (DPN). Various CMAP scan variables, including measures of axonal excitability and axonal loss and reinnervation, were compared between patients and healthy controls.

RESULTS

Axonal excitability was significantly decreased in the young patient groups as compared to their controls. The CMAP scan measures of axonal loss and reinnervation differed only between patients with clinical DPN and their controls.

CONCLUSIONS

Motor nerve axonal excitability seems to be reduced early in T1DM, even in well-controlled young patients, and probably before (irreversible) axonal damage occurs. These changes can be measured by the CMAP scan, which makes this a promising tool for detecting nerve dysfunction in T1DM.

Validity of the neurological examination in diagnosing diabetic peripheral neuropathy

The aim of this study was to evaluate the prevalence of diabetic peripheral neuropathy in children and adolescents with type 1 diabetes mellitus and examine whether the neurological examination validly diagnoses diabetic peripheral neuropathy as compared with the gold standard of nerve conduction velocity in these patients. Nerve conduction velocity was measured in an unselected consecutive series of patients aged 8-18 years who had been suffering from type 1 diabetes mellitus for at least 1 year. For the neurological examination, neuropathy disability scores and neuropathy sign scores were used. Of the 39 patients, six (15%) had clinically evident diabetic peripheral neuropathy, whereas nerve conduction velocity testing revealed diabetic peripheral neuropathy in 15 (38%) patients. Sensitivity and specificity of the neurological examination for the diagnosis of diabetic peripheral neuropathy were 40% and 100%, respectively. The corresponding positive and negative predictive values were 100% and 72.7%, respectively. This conclusions from this study are that in children and adolescents with type 1 diabetes mellitus, diabetic peripheral neuropathy is highly prevalent, but in the majority of patients it is subclinical. Sensitivity and negative predictive values of the neurological examination are low. Therefore, routine nerve conduction velocity measurement for the assessment of diabetic peripheral neuropathy appears to be warranted in these patients.