Redefining distal symmetrical polyneuropathy features in type 1 diabetes: a systematic review

Abstract

Diabetic neuropathy is among the most frequent complications of both type 1 (T1DM) and type 2 diabetes (T2DM) and commonly manifests as a distal symmetrical polyneuropathy (DSPN). Despite evidence that T1DM- and T2DM-related DSPN are separate entities, most of our knowledge on diabetic DSPN derives from studies focused on type 2 diabetes. This systematic review provides an overview of current evidence on DSPN in T1DM, including its epidemiological, pathophysiological and clinical features, along with principal diagnostic tests findings. This review included 182 clinical and preclinical studies. The results indicate that DSPN is a less frequent complication in T1DM compared with T2DM and that distinctive pathophysiological mechanisms underlie T1DM-related DSPN development, with hyperglycemia as a major determinant. T1DM-related DSPN more frequently manifests with non-painful than painful symptoms, with lower neuropathic pain prevalence compared with T2DM-associated DSPN. The overt clinical picture seems characterized by a higher prevalence of large fiber-related clinical signs (e.g., ankle reflexes reduction and vibration hypoesthesia) and to a lesser extent small fiber damage (e.g., thermal or pinprick hypoesthesia). These findings as a whole suggest that large fibers impairment plays a dominant role in the clinical picture of symptomatic T1DM-related DSPN. Nevertheless, small fiber diagnostic testing shows high diagnostic accuracy in detecting early nerve damage and may be an appropriate diagnostic tool for disease monitoring and screening.

Physiological Changes and Pathological Pain Associated with Sedentary Lifestyle-Induced Body Systems Fat Accumulation and Their Modulation by Physical Exercise

“…Distal symmetric polyneuropathy (DSP), a type of peripheral neuropathy, has been described in subjects with metabolic syndrome [401,402]. It is well known that DSP is associated with pain, falls, and reduced quality of life [403][404][405][406][407][408][409][410][411][412]. On the other hand, metabolic syndrome also is associated with an elevated risk for cryptogenic sensory peripheral neuropathy (CSPN), which preferentially affects small unmyelinated axons early in its course, and it may affect autonomic and large fibers [413].…”

Peripheral and Autonomic Neuropathy Status of Young Patients With Type 1 Diabetes Mellitus at the Time of Transition From Pediatric Care to Adult-Oriented Diabetes Care

“…However, peripheral neuropathies may affect different types of nerve fibers to different degrees, and the usual concept is that sensory nerves in the lower limb are predominantly affected and symptoms begin at the terminal of the longest nerves in diabetes mellitus (54). On the other hand, the proper diagnosis of diabetic peripheral sensory neuropathy, mostly at the early stages, remains challenging, and several recent reviews summarize the current approaches and suggest strategies to further improve diagnostic testing (55,56).…”

Corneal nerve and nerve conduction abnormalities in children with type 1 diabetes

“…13 Although diabetic neuropathy is known to primarily affect large nerve fibers, small fiber impairment is also being observed, especially early during the subclinical phase. 12 In vivo corneal confocal microscopy (CCM) is a rapid, non-invasive technique that identifies early small fiber damage and can predict the progression 14 and development 15,16 of clinical neuropathy in adults with type 1 diabetes. It correlates with intra-epidermal nerve fiber density, autonomic neuropathy and nerve conduction studies with various definition of diabetic peripheral neuropathy.…”

“…7,8 Abnormalities in motor and sensory nerve conduction studies (NSC) have been reported in $20%-34.5% of children with type 1 diabetes. [9][10][11][12] Due to the absence of clinical symptoms and signs, lack of good pediatric normative data, and technical challenges in performing quantitative sensory testing (QST) 12 and other neurophysiological assessments, the diagnosis of early diabetic neuropathy is challenging in children. 13 Although diabetic neuropathy is known to primarily affect large nerve fibers, small fiber impairment is also being observed, especially early during the subclinical phase.…”

“…Generally, children and adolescents do not have signs or symptoms of diabetic polyneuropathy 4–6 and screening tools recommended for adults, such as clinical examination and the Semmes‐Weinstein microfilament, are unreliable, especially in children 7,8 . Abnormalities in motor and sensory nerve conduction studies (NSC) have been reported in ~20%–34.5% of children with type 1 diabetes 9–12 . Due to the absence of clinical symptoms and signs, lack of good pediatric normative data, and technical challenges in performing quantitative sensory testing (QST) 12 and other neurophysiological assessments, the diagnosis of early diabetic neuropathy is challenging in children 13 …”