Pain exacerbation following physical activity in adults with diabetic neuropathy: Ecological momentary assessment of foot symptoms.

BACKGROUND AND OBJECTIVES: People with diabetic peripheral neuropathy (DPN) report fluctuating foot symptoms. This study used ecological momentary assessment to: (1) compare foot symptoms between days, time points and periods with/without preceding physical activity or pain medication; and (2) determine relationships between symptoms and endogenous pain modulation. METHOD: Ten low-active Australian adults with probable DPN underwent temporal summation of pain (TSP) and conditioned pain modulation (CPM) then completed mobile phone surveys five times daily for seven days, where they recorded the intensity of six foot symptoms and whether they performed physical activity or consumed pain medication in the preceding three hours.  RESULTS: All foot symptoms except numbness were greater in periods following physical activity, whereas periods following pain medication showed greater shooting pain. TSP showed very large correlations with sensitivity to touch, burning pain, shooting pain and prickling/tingling.  DISCUSSION: General practitioners should be aware that physical activity might exacerbate symptoms of DPN when encouraging their patients to be active.

Personal Activity Intelligence eHealth intervention in people with diabetic peripheral neuropathy: A feasibility study.

BACKGROUND AND OBJECTIVES: People with diabetic peripheral neuropathy (DPN) report difficulty exercising. This study tested an innovative intervention to promote physical activity self-management and its impact on foot symptoms. METHOD: Ten adults with DPN not meeting exercise guidelines consented to four weekly sessions involving exercise tasters, behaviour change counselling and Physical Activity Intelligence (PAI) self-monitoring, with a goal to maintain daily PAI scores ≥100. Foot symptoms were assessed using repeated mobile phone surveys at 0 and 12 weeks. RESULTS: Participants attended a mean 3.5 sessions and achieved 100 PAI on 53% and 15% of days during Weeks 2-4 and 5-12, respectively. No major adverse events and large reductions in aching (P=0.02) and burning pain (P=0.03) in the feet were recorded. DISCUSSION: The PAI eHealth intervention was feasible and safe and might reduce foot symptoms. More work is needed to support self-directed exercise maintenance.

Occurrence of corneal sub-epithelial microneuromas and axonal swelling in people with diabetes with and without (painful) diabetic neuropathy.

AIMS/HYPOTHESIS: Non-invasive in vivo corneal confocal microscopy is gaining ground as an alternative to skin punch biopsy to evaluate small-diameter nerve fibre characteristics. This study aimed to further explore corneal nerve fibre pathology in diabetic neuropathy. METHODS: This cross-sectional study quantified and compared corneal nerve morphology and microneuromas in participants without diabetes (n=27), participants with diabetes but without distal symmetrical polyneuropathy (DSPN; n=33), participants with non-painful DSPN (n=25) and participants with painful DSPN (n=18). Clinical and electrodiagnostic criteria were used to diagnose DSPN. ANCOVA was used to compare nerve fibre morphology in the central cornea and inferior whorl, and the number of corneal sub-epithelial microneuromas between groups. Fisher's exact tests were used to compare the type and presence of corneal sub-epithelial microneuromas and axonal swelling between groups. RESULTS: Various corneal nerve morphology metrics, such as corneal nerve fibre length and density, showed a progressive decline across the groups (p<0.001). In addition, axonal swelling was present more frequently (p=0.018) and in higher numbers (p=0.03) in participants with painful compared with non-painful DSPN. The frequency of axonal distension, a type of microneuroma, was increased in participants with painful and non-painful DSPN compared to participants with diabetes but without DSPN and participants without diabetes (all p≤0.042). The combined presence of all microneuromas and axonal swelling was increased in participants with painful DSPN compared with all other groups (p≤0.026). CONCLUSIONS/INTERPRETATION: Microneuromas and axonal swelling in the cornea increase in prevalence from participants with diabetes to participants with non-painful DSPN and participants with painful DSPN.

Diabetic Neuropathy in Hands: An Endemic Complication Waiting to Unfold?

In this cross-sectional study we aimed to quantify the somatosensory dysfunction in the hand in people with diabetes with distal symmetrical polyneuropathy (DSPN) in hands and explore early signs of nerve dysfunction in people with diabetes without DSPN in hands. The clinical diagnosis of DSPN was confirmed with electrodiagnosis and corneal confocal microscopy. Thermal and mechanical nerve function in the hand was assessed with quantitative sensory tests. Measurements were compared between healthy participants (n = 31), individuals with diabetes without DSPN (n = 35), individuals with DSPN in feet but not hands (DSPNFEET ONLY) (n = 31), and individuals with DSPN in hands and feet (DSPNHANDS & FEET) (n = 28) with one-way between-group ANOVA. The somatosensory profile of the hand in people with DSPNHANDS & FEET showed widespread loss of thermal and mechanical detection. This profile in hands is comparable with the profile in the feet of people with DSPN in feet. Remarkably, individuals with DSPNFEET ONLY already showed a similar profile of widespread loss of nerve function in their hands. People with diabetes without DSPN in feet already had some nerve dysfunction in their hands. These findings suggest that nerve function assessment in hands should become more routine in people with diabetes.

Spatial variation in mechanical properties along the sciatic and tibial nerves: An ultrasound shear wave elastography study.

Ultrasound shear wave elastography has become a promising method in peripheral neuropathy evaluation. Shear wave velocity, a surrogate measure of stiffness, tends to increase in peripheral neuropathies regardless of etiology. However, little is known about the spatial variation in shear wave velocity of healthy peripheral nerves and how tensile loading is distributed along their course. Sixty healthy young adults were scanned using ultrasound shear wave elastography. Five regions of the sciatic (SciaticPROXIMAL, SciaticDISTAL) and tibial nerve (TibialPROXIMAL, TibialINTERMEDIATE, and TibialDISTAL) were assessed in two hip positions that alter nerve tension: 1) neutral in supine position; and 2) flexed at 90°. Knee and ankle remained in full-extension and neutral position. We observed spatial variations in shear wave velocity along the sciatic and tibial nerve (P < 0.0001). Shear wave velocities were significantly different between all nerve locations with the exception of SciaticDISTAL vs. TibialINTERMEDIATE (P = 0.999) and TibialPROXIMAL vs. TibialINTERMEDIATE (P = 0.708), and tended to increase in the proximal-distal direction at both upper and lower leg segments. Shear wave velocity increased with hip flexion (+54.3%; P < 0.0001), but the increase was not different among nerve locations (P = 0.233). This suggests that the increase in tensile loading with hip flexion is uniformally distributed along the nerve tract. These results highlight the importance of considering both limb position and transducer location for biomechanical and clinical assessments of peripheral nerve stiffness. These findings provide evidence about how tension is distributed along the course of sciatic and tibial nerves.

Altered pain processing in patients with type 1 and 2 diabetes: systematic review and meta-analysis of pain detection thresholds and pain modulation mechanisms.

The first signs of diabetic neuropathy typically result from small-diameter nerve fiber dysfunction. This review synthesized the evidence for small-diameter nerve fiber neuropathy measured via quantitative sensory testing (QST) in patients with diabetes with and without painful and non-painful neuropathies. Electronic databases were searched to identify studies in patients with diabetes with at least one QST measure reflecting small-diameter nerve fiber function (thermal or electrical pain detection threshold, contact heat-evoked potentials, temporal summation or conditioned pain modulation). Four groups were compared: patients with diabetes (1) without neuropathy, (2) with non-painful diabetic neuropathy, (3) with painful diabetic neuropathy and (4) healthy individuals. Recommended methods were used for article identification, selection, risk of bias assessment, data extraction and analysis. For the meta-analyses, data were pooled using random-effect models. Twenty-seven studies with 2422 participants met selection criteria; 18 studies were included in the meta-analysis. Patients with diabetes without symptoms of neuropathy already showed loss of nerve function for heat (standardized mean difference (SMD): 0.52, p<0.001), cold (SMD: -0.71, p=0.01) and electrical pain thresholds (SMD: 1.26, p=0.01). Patients with non-painful neuropathy had greater loss of function in heat pain threshold (SMD: 0.75, p=0.01) and electrical stimuli (SMD: 0.55, p=0.03) compared with patients with diabetes without neuropathy. Patients with painful diabetic neuropathy exhibited a greater loss of function in heat pain threshold (SMD: 0.55, p=0.005) compared with patients with non-painful diabetic neuropathy. Small-diameter nerve fiber function deteriorates progressively in patients with diabetes. Because the dysfunction is already present before symptoms occur, early detection is possible, which may assist in prevention and effective management of diabetic neuropathy.

Understanding the knowledge, attitudes and practices of providing and receiving nutrition care for prediabetes: an integrative review.

To synthesise the literature on nutrition care for prediabetes from both the perspective of healthcare providers and patients, six databases (CINAHL, MEDLINE, Embase, PsycINFO, Scopus and ProQuest) were searched to identify qualitative or quantitative studies that focussed on nutrition care and prediabetes in primary care practice. Studies examining the perspectives of patients with prediabetes and healthcare providers were included. Outcomes of interest included knowledge of nutrition care for prediabetes, attitudes around providing or receiving nutrition care and actual nutrition care practices for prediabetes. Overall, 12851 studies were screened and 26 were included in the final review. Inductive analysis produced five themes: (i) nutrition care is preferable to pharmacological intervention; (ii) patients report taking action for behaviour change; (iii) healthcare providers experience barriers to nutrition care; (iv) healthcare providers tend not to refer patients for nutrition care; and (v) there are contradictory findings around provision and receipt of nutrition care. This review has revealed the contradictions between patients' and healthcare providers' knowledge, attitudes and practices around nutrition care for prediabetes. Further research is needed to shed light on how to resolve these disconnects in care and to improve nutrition care practices for people with prediabetes.

Neural Tension Technique Improves Immediate Conditioned Pain Modulation in Patients with Chronic Neck Pain: A Randomized Clinical Trial.

OBJECTIVE: To determine the immediate effect of neural tension technique (NTT) on conditioned pain modulation in patients with chronic neck pain. A secondary objective was to determine the immediate effect of neural tensioner technique on pain intensity and cervical range of movement. DESIGN: Randomized clinical trial. SETTING: University medical center. SUBJECTS: Fifty-four patients with neck pain (13 males and 41 females; mean± SD age = 20.91 ± 2.64 years) were randomly allocated to two groups: NTT or sham technique. METHODS: Participants received a visual analog scale (VAS) and neck disability index (NDI) after inclusion. Conditioned pain modulation (CPM) and active cervical range of motion were measured before and after the intervention. Each subject received one treatment session. RESULTS: The results of the analysis of variance revealed a significant effect for the group × time interaction only for CPM (F = 11.09, P = 0.002, ηp2 = 0.176). No significant interactions were found for the other measures (VAS [F = 1.719, P = 0.195, ηp2 = 0.031], pressure pain threshold C2 [F = 0.731, P = 0.398, ηp2 = 0.018], flexion [F = 0.176, P = 0.677, ηp2 = 0.003], extension [F = 0.035, P = 0.852, ηp2 = 0.001], lateral flexions [F = 0.422, P = 0.519, ηp2 = 0.008], and rotations [F = 1.307 P = 0.258, ηp2 = 0.024]). Regarding CPM, intergroup interaction differences were found postintervention (P = 0.002) with a high effect size (d = 0.98). CONCLUSIONS: This study suggests that neural tension technique enhances immediate conditioned pain modulation in patients with chronic neck pain, but not pain intensity or cervical range of movement.

Altered pain processing in people with type I and II diabetes: a protocol for a systematic review and meta-analysis of pain threshold and pain modulation mechanisms.

BACKGROUND: Peripheral neuropathies are a common complication in patients with diabetes. Changes in nerve function and central pain processing can be quantified by assessing pain thresholds and pain modulation mechanisms. AIM: To summarise the literature which compares pain thresholds and pain modulation mechanisms in people with diabetes without neuropathies, with non-painful diabetic neuropathies and with painful diabetic neuropathies, and in people without diabetes. METHODS: A systematic review and meta-analysis will be conducted. Terms related to diabetes, pain thresholds and pain modulation mechanisms will be combined in a structured search in MEDLINE, CINAHL, EMBASE, the Cochrane Library, SPORTDiscus, Web of Science and PEDro. Publications on adults (18 years and older) with diabetes and at least one pain threshold measure following thermal, mechanical or electrical stimuli and/or at least one pain modulation mechanisms (temporal summation or conditioned pain modulation) with a comparison group will be considered. There will be no restriction regarding language or year of publication. One investigator will screen records based on title and abstract (ESS). Two independent investigators (ESS and MC) will select full-text papers and assess risk of bias using a modified Downs and Black checklist. Potential disagreements will be resolved with a third investigator (LB). One investigator (ESS) will extract all data and a second investigator (MS) will extract data for 20% of the papers to verify accuracy of the process. A sensitivity analysis for publication bias will be conducted. DISCUSSION: This systematic review and meta-analysis will summarise the evidence on pain threshold profiles and pain modulation mechanisms in people with diabetes without and with neuropathies (both painful and non-painful). This will provide more insight in the clinical presentation and progression of diabetic neuropathies. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018088173.

Femoral nerve excursion with knee and neck movements in supine, sitting and side-lying slump: An in vivo study using ultrasound imaging.

BACKGROUND: Neurodynamic assessment and management are advocated for femoral nerve pathology. Contrary to neurodynamic techniques for other nerves, there is limited research that quantifies femoral nerve biomechanics. OBJECTIVES: To quantify longitudinal and transverse excursion of the femoral nerve during knee and neck movements. DESIGN: Single-group, experimental study, with within-participant comparisons. METHODS: High-resolution ultrasound recordings of the femoral nerve were made in the proximal thigh/groin region in 30 asymptomatic participants. Scans were made during knee flexion in supine and a semi-seated position, and during neck flexion in side-lying slump (Slump FEMORAL). Healthy participants were assessed to reveal normal nerve biomechanics, not influenced by pathology. Data were analysed with one-sample and paired t-tests. Reliability was assessed with intraclass correlation coefficients (ICC). RESULTS: Longitudinal and transverse excursion measurements were reliable (ICC≥0.87). With knee flexion, longitudinal femoral nerve excursion was significant and larger in supine than in sitting (supine (mean (SD)): 3.6 (2.0) mm; p < 0.001; sitting: 1.1 (1.6) mm; p = 0.001; comparison: p = 0.001). There was also excursion in a medial direction (supine: 1.4 (0.3) mm; p < 0.001; sitting: 0.7 (0.6) mm; p < 0.001) and anterior direction (supine: 0.2 (0.2) mm; p < 0.001; sitting: 0.1 (0.2) mm; p = 0.06). Neck flexion in Slump FEMORAL did not result in longitudinal (0.0 (0.3) mm; p = 0.55) or anteroposterior (0.0 (0.1) mm; p = 0.10) excursion, but resulted in medial excursion (1.1 (0.5) mm; p < 0.001). CONCLUSION: Although the femoral nerve terminates proximal to the knee, femoral nerve excursion in the proximal thigh occurred with knee flexion; Neck flexion in Slump FEMORAL resulted in medial excursion.

Effect of leg dominance, gender and age on sensory responses to structural differentiation of straight leg raise test in asymptomatic subjects: a cross-sectional study.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To assess the effect of structural differentiation on sensory responses of asymptomatic individuals to standard neurodynamic tests of straight leg raise (SLR) and to evaluate the relevance of leg dominance, gender, and age. BACKGROUND: SLR test is a well-known neurodynamic test among physical therapists; no studies to date have investigated the influence of gender, age, and leg dominance to the sensory responses of this neurodynamic test and its structured differentiating maneuver. METHODS: Thirty (16 women) asymptomatic individuals enrolled in this study. Dominancy test was performed for each participant. Pain intensity using visual analogue scale (VAS), symptoms location in a body chart, nature of symptoms evoked, and hip range of motion (ROM) were recorded and compared at ankle neutral position (N-SLR) and dorsiflexion (DF-SLR) in both legs at the point of pain tolerance during SLR (P2). In addition, hip ROM was recorded at the onset of pain (P1). RESULTS: There was a statistically significant sex main effect for P1 and P2 between N-SLR and DF-SLR (p < 0.05). Mean hip ROM during the SLR was more than 10° greater in women than men. There was no statistically significant interaction between leg dominance and age group in N-SLR, DF-SLR, and VAS. Pain intensity was moderate for each SLR test. Symptoms most often described were stretch (96.7%), followed by tightness (70%) in the posterior thigh and leg. CONCLUSIONS: SLR hip ROM is influenced by sex in asymptomatic individuals, leading to a greater hip ROM in SLR in women. Age and limb dominance are not relevant to SLR hip ROM or pain intensity.