Choosing a Vibratory Test to Pair With Semmes Weinstein Monofilament Testing for Evaluating Lower Extremity Sensation in Patients With Diabetes: A Comparison of Three Vibratory Methodologies

Can the 128-Hz tuning fork be an alternative to the biothesiometer for diabetic peripheral neuropathy screening? A cross-sectional study in a tertiary hospital in East India

INTRODUCTION

Diabetic neuropathy is frequently underdiagnosed and undertreated. Logistic problems accompany the routine use of the biothesiometer. Hence, we attempted to find a more easily available alternative.

RESEARCH DESIGN AND METHODS

149 patients with diabetes visiting the outpatient endocrinology clinic were assessed for vibration sense using a 128-Hz tuning fork (absolute timing method) and a biothesiometer. A reading of >25 V on the biothesiometer (known as vibration perception threshold or VPT) was taken as the diagnostic criterion for severe neuropathy while >15 V was used as an indicator of the mild form. The sensitivity and specificity were calculated by constructing the receiver operating characteristic curve (ROC). A p value of <0.05 was considered as statistically significant.

RESULTS

The timed tuning fork (TTF) test showed a statistically significant correlation with the VPT measurements (r=-0.5, p=0.000). Using the VPT findings as a reference, a timed tuning fork cut-off of 4.8 s was 76% sensitive and 77% specific in diagnosing mild neuropathy while absent tuning fork sensation demonstrated 70% sensitivity and 90% specificity in detecting severe neuropathy.

CONCLUSIONS

The tuning fork test demonstrated significant sensitivity and specificity in diagnosing diabetic peripheral neuropathy when compared against the biothesiometer. A cut-off of 4.8 s can be a useful indicator of the early stages of onset of the condition.

The usage of a modified straight-leg raise neurodynamic test and hamstring flexibility for diagnosis of non-specific low back pain: A cross-sectional study

OBJECTIVES

The main purpose of this research study was to compare mean modified straight-leg raise test (mSLR) and hamstring muscle length (HL) between chronic non-specific low back pain (LBP) and healthy subjects to understand the possibility of neuropathic causes in LBP population as it may impact the diagnosis and treatment of LBP. Another purpose was to compare mean mSLR between those with lumbar nerve root impingement and those without as determine by magnetic resonance imaging (MRI).

METHODS

The design of the study is cross sectional and included 32 subjects with ages ranging from 18-50 years old. Clinical exam objective measures were collected such as patient questionnaires, somatosensory tests, HL range of motion, and a mSLR test, and were compared to the findings from a structural lumbar spine MRI.

RESULTS

There were no significant differences in mean HL angulation and mSLR angulation between LBP and healthy subjects (p>0.05). There was no significant difference in mean HL by impingement by versus no impingement (38.3±15.6 versus 44.8±9.4, p = 0.08, Cohen's d = 0.50). On the other hand, there was a significant difference in mean mSLR angulation by impingement (57.6.3±8.7 versus 63.8±11.6, p = 0.05, Cohen's d = 0.60).

CONCLUSIONS

The mSLR test was found to be associated with lumbar nerve root compression, regardless of the existence of radiating leg symptoms, and showed no association solely with the report of LBP. The findings highlight the diagnostic dilemma facing clinicians in patients with chronic nonspecific LBP with uncorrelated neuroanatomical image findings. Clinically, it may be necessary to reevaluate the common practice of exclusively using the mSLR test for patients with leg symptoms. This study may impact the way chronic LBP and neuropathic symptoms are diagnosed, potentially improving treatment methods, reducing persistent symptoms, and ultimately improving disabling effects.

On the mechanics of monofilaments used in touch sensory perception

The buckling of a slender monofilament is a standard clinical method used to assess touch sensory perception, with specific applications to somatosensory impairment in patients after a stroke, detecting carpal tunnel syndrome, and as a prognosis tool for diabetic peripheral neuropathy. The basis of this approach is the Semmes-Weinstein monofilament, which comprises a calibrated set of thin, polycarbonate rods with different diameters. Application of a monofilament onto the surface of the skin with increasing pressure causes the rod to buckle. That is, at a specific force of pushing down on the far end, the monofilament suddenly bows out sidewards - the buckling load. The ability of a patient to detect increasingly finer monofilament buckling (pressure threshold) is then used to assess sensory deterioration. This paper addresses the underlying mechanics of the buckling process. Despite the accuracy and repeatability problems that have been reported in the literature, and the necessarily subjective aspects of sensory physiology, the mathematical modeling of the monofilament buckling is unambiguous and provides some fundamental insight into the parameters that underlie this approach.

Skin Sensitivity Assessment Using Smartphone Haptic Feedback

Goal: This work presents a smartphone application to assess cutaneous sensory perception by establishing Vibrational Perception Thresholds (VPTs). Cutaneous sensory perception diagnostics allow for the early detection and symptom tracking of tactile dysfunction. However, lack of access to healthcare and the limited frequency of current screening tools can leave skin sensation impairments undiscovered or unmonitored. Methods: A 23-participant cross-sectional study in subjects with a range of finger sensation tests Smartphone Established VPTs (SE-VPTs) by varying device vibrational intensity. These are compared against monofilament test scores, a clinical measure of skin sensitivity. Results: We find a strong positive correlation between SE-VPTs and monofilament scores ([Formula: see text] = 0.86, p = 1.65e-07). Conclusions: These results demonstrate the feasibility of using a smartphone as a skin sensation screening tool.

Effects of stochastic resonance stimulation on manual function in children with hemiplegic cerebral palsy: A pilot clinical trial

OBJECTIVE

To investigate the effect of stochastic resonance stimulation (SRS) on manual abilities in children with hemiplegic cerebral palsy.

DESIGN

This pilot study is a randomized, sham-controlled, one-period, crossover trial.

SETTING

A neuroscience clinic with specialty therapy programs at an urban, university-based children's hospital.

PARTICIPANTS

Sixteen children ages 3 to 16 years who were diagnosed with hemiplegic cerebral palsy and had hand Manual Abilities Classification scale score of I to III with sufficient cognitive abilities to follow instructions.

INTERVENTIONS

Children donned wrist and arm bands that delivered SRS via embedded piezoelectric actuators in two randomly assigned conditions: sham (devices powered off) and subthreshold stimulation (SBT-SRS). Following the randomized protocol, a subset of participants also completed an open-label, above-threshold stimulation (AT-SRS) condition. Children carried out the same uni-manual and bimanual tasks during the randomized and open-label protocols; all data were collected in a single session.

MAIN OUTCOME MEASURE(S)

Box and Blocks (B&B) test, a uni-manual function test, and the Shriners Hospital Upper Extremity Evaluation (SHUEE). The SHUEE was video recorded and scored by two raters who were blinded to the experimental condition.

RESULTS

Thirteen children completed the B&B task and 14 children completed the SHUEE. Children in the SBT-SRS condition relative to sham condition moved an average of 1.8 more blocks in 1 minute (p = .08); scored an average of 3 points higher on SHUEE spontaneous functional analysis (p < .002); and scored an average of 2.7 points higher on SHUEE dynamic positional analysis (p = .20). In the open-label protocol, children in the AT-SRS condition relative to sham moved 3.9 more blocks than in the sham condition (n = 8, p < .001); scored an average of 4.5 points higher on SHUEE spontaneous functional analysis (n = 6, p = .08); and scored an average of 10.5 points higher on SHUEE dynamic positional analysis (n = 6, p = .01).

CONCLUSION(S)

In this pilot study, we found preliminary evidence that children with hemiplegic cerebral palsy demonstrated improved uni-manual abilities and increased function of the impaired hand on bimanual tasks when receiving a single session of SBT-SRS. Preliminary evidence also suggests that some children with hemiplegic cerebral palsy may improve more when receiving a single session of AT-SRS. Future research using larger, controlled studies should evaluate the optimal intensity, duration, and long-term effect of SRS for improving impaired manual abilities.

Validity and Reliability of Criteria for Plantar Sensation Assessment Using Semmes-Weinstein Monofilament as a Clinically Usable Index

There is no standard clinically adaptable criterion for assessing plantar sensation for pre- and post-intervention comparisons. Studies using Semmes-Weinstein monofilaments (SWMs) to investigate intervention effects on plantar sensation vary in procedure and do not consider measurement errors. This study aimed to develop a simple criterion using SWMs to assess plantar sensation, determine the measurement error range, and identify areas of low error. Six examiners assessed 87 healthy young adults in Experiment 1, while two examiners assessed 10 participants in Experiment 2. Filaments were graded from 1 to 20 based on increasing diameter. The smallest grade that could be perceived for three sequential stimuli was used as the criterion (smallest perceivable grade, SPG). The SPG was significantly smaller at the hallux and larger at the heel than at other sites. There were no significant differences between the SPG of the repeated tests performed by the same versus different examiners. The interquartile range of the differences was <±3 at all sites. Thus, our criteria were reliable in evaluating the effects of plantar sensation interventions, especially at the heel and the middle of the metatarsal heads and could contribute to the development of more effective treatments for plantar sensations.

Combined Utility of the Semmes-Weinstein Monofilament and the Timed Vibration Test in the Prediction of Diabetic Foot Ulcers

BACKGROUND

Neurologic screening tests are often used to identify and stratify patients at risk for diabetic foot complications such as infections, ulcers, and amputations. Two of the most commonly cited methods are the 5.07 Semmes-Weinstein monofilament (SWM) for loss of protective sensation and vibratory sensation testing. The aim of this study was to determine whether combined SWM and the timed vibration test (TVT) more effectively predicts diabetic foot ulcer (DFU) development compared with each test alone.

METHODS

An electronic medical record database search was performed restricted to podiatric medical clinic patients with diabetes and DFU ICD-10 diagnosis codes. Of 200 patients who met the criteria, 24 developed DFUs. A statistical analysis was performed comparing the SWM and TVT at various cutoff times and the combined SWM/TVT in their ability to predict DFUs.

RESULTS

Statistical analysis revealed that the TVT cutoff time of less than 4 sec was superior to the other times for prediction of DFUs. The combined SWM/TVT results at less than 4 sec were superior to each test individually: sensitivity, 87.5%; specificity, 84.7%; positive predictive value, 43.8%; and receiver operating characteristics area under the curve, 0.86.

CONCLUSIONS

The SWM combined with TVT was shown to be superior compared with either test alone in discriminating DFU risk. In addition, the TVT cutoff time of less than 4 sec proved to have greater diagnostic yield than other times, including 0 sec. This unexpected finding might impact providers relying on the absence of vibration sensation via tuning fork testing as an optimal marker of DFU risk.

Therapeutic outcomes evaluation of adjuvant hyperbaric oxygen therapy for non-healing diabetic foot ulcers among sudanese patients

BACKGROUND AND AIMS

Diabetic foot ulcers (DFUs) are common complications of diabetes that frequently lead to amputation and disability. Despite some promising results in using hyperbaric oxygen therapy (HBOT) for DFUs treatment, its efficacy is still debatable. The aim of this study was to evaluate the therapeutic outcomes of adjuvant HBOT in non-healing DFUs treatment.

METHODS

A descriptive, retrospective, hospital-based study was conducted at Al-Mo'alem Medical City-Khartoum, Sudan from August to December 2018. Medical records of Type 2 diabetic patients, treated with HBOT plus standard wound care for DFUs, were included in the study. Data were analyzed by simple descriptive statistics and logistic regression. P ≤ 0.05 was considered statistically significant.

RESULTS

The study results showed that 51.7% of patients had Wagner grade-3 ulcers and 28.3% had complete loss of protective sensation. Almost 61% of patients achieved complete ulcer healing while 16.7% underwent amputation. Twenty percent of patients treated with HBOT experienced ear barotraumas as adverse effects. Protective sensation (OR = 6.00, 95% CI = 1.79-20.16, p = 0.004) and more sessions of HBOT (OR = 17.35, 95% CI = 4.51-66.73, p = 0.000) were positive predictors of complete ulcer healing. Loss of protective sensation (OR = 0.17, 95% CI = 0.05-0.63, p = 0.007) was an indicator of amputation.

CONCLUSIONS

Treatment with adjuvant HBOT enhanced ulcer healing and reduced amputation rate in patients with non-healing DFUs. HBOT could be considered a relatively safe intervention.

Aging and the Relationship between Balance Performance, Vestibular Function and Somatosensory Thresholds

OBJECTIVES

The objective of this study was two-fold: (1) To evaluate the impact of the physiological aging process on somatosensory, vestibular, and balance functions, and (2) To examine the extent to which age and somatosensory and vestibular functions can predict balance performance.

MATERIALS AND METHODS

In this cross-sectional study, 141 asymptomatic subjects were assessed for touch pressure thresholds (TPT) with Semmes-Weinstein monofilaments (SWF), vibration thresholds (VT) with a neurothesiometer (NT) and a Rydel-Seiffer tuning fork 128Hz (RSTF). Horizontal vestibulo-ocular reflexes (HVOR gain and asymmetry) were assessed using the video Head Impulse Test (vHIT). A modified version of the Romberg test was used to assess standing balance and the Timed Up and Go test (TUG) and tandem gait (TG) to evaluate dynamic balance.

RESULTS

Significant age effects were found for TPT, VT, and balance but not for HVOR gain or asymmetry. Standing balance was explained for 47.2% by age, metatarsal 1 (MT1) (NT), and heel (SWF). The variance in TUG performance was explained for 47.0% by age, metatarsal 5 (MT5) (SWF), and medial malleolus (MM) (NT). Finally, the variance in TG performance was predicted for 43.1% by age, MT1 (NT), HVOR gain, and heel (SWF).

CONCLUSION

Among asymptomatic adult population, both somatosensation and balance performance deteriorate with aging. In contrast, HVOR remains rather constant with age, which is possibly explained by the process of vestibular adaptation. Furthermore, this study provides evidence that the VT, TPT, HVOR gain, and age partly predict balance performance. Still, further research is needed, especially with bigger samples in decades 8 and 9.