Correlation between two-point discrimination with other measures of sensory loss in diabetes mellitus patients
01 Jul 2008-International Journal of Diabetes in Developing Countries (Int J Diabetes Dev Ctries)-Vol. 28, Iss: 3, pp 71-78
TL;DR: The TPD appears to be measuring different property of the foot compared to other measures, and the mechanism of this independence is not well understood and more investigation is required to understand the mechanism.
Abstract: Diabetic neuropathy is one of the most important factors for foot ulceration in diabetes mellitus (DM) patients. Among different sensibility measures of neuropathy, two-point discrimination (TPD) has been suggested as a reliable method; however, the correlation of TPD with other well-known measures is not known. We measured the loss of protective sensation using Semmes-Weinstein Monofilaments (SWMF), hardness of the foot sole using shore meter (sh), power ratio (PR) using pedopowergraph and TPD using esthesiometer in foot areas of both left and right legs in 14 DM subjects. We have found no correlation either between TPD and shore values (sh) or between TPD and PR. The SWMF (10 g) is found not to provide any additional value in measuring loss of sensation in comparison to TPD. The TPD appears to be measuring different property of the foot compared to other measures. The mechanism of this independence is not well understood and more investigation is required to understand the mechanism.
Citations
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TL;DR: There was variation in plantar pressure distribution because the contact area of the men foot was larger than that of women foot, which can provide suitable guidelines to biomedical engineers and doctor for designing orthotic devices for reliving the area of excessively high pressure.
33 citations
TL;DR: Subjective symptoms and objective peripheral nerve disturbances of both small and large fibers occurred at low ACDW (> 50 ppb), suggesting a threshold for the occurrence of peripheral neuropathy due to arsenic exposure, and indicating that the arsenic concentration in drinking water should be less than 10 ppB to ensure human health.
Abstract: More than 140 million people drink arsenic-contaminated groundwater. It is unknown how much arsenic exposure is necessary to cause neurological impairment. Here, we evaluate the relationship between neurological impairments and the arsenic concentration in drinking water (ACDW). A cross-sectional study design was employed. We performed medical examinations of 1867 residents in seven villages in the Thabaung township in Myanmar. Medical examinations consisted of interviews regarding subjective neurological symptoms and objective neurological examinations of sensory disturbances. For subjective neurological symptoms, we ascertained the presence or absence of defects in smell, vision, taste, and hearing; the feeling of weakness; and chronic numbness or pain. For objective sensory disturbances, we examined defects in pain sensation, vibration sensation, and two-point discrimination. We analyzed the relationship between the subjective symptoms, objective sensory disturbances, and ACDW. Residents with ACDW ≥ 10 parts per billion (ppb) had experienced a “feeling of weakness” and “chronic numbness or pain” significantly more often than those with ACDW 50 ppb). These data suggest a threshold for the occurrence of peripheral neuropathy due to arsenic exposure, and indicate that the arsenic concentration in drinking water should be less than 10 ppb to ensure human health.
30 citations
TL;DR: In this paper, the authors evaluated two-point discrimination (TPD) compared with nerve conduction studies in the early stages of type 2 diabetes mellitus and found that higher TPD values in the lower extremities indicate nerve damage in patients.
Abstract: Background
Diabetes mellitus (DM) is a common cause of polyneuropathy. The aim of the present study was to evaluate two-point discrimination (TPD) compared with nerve conduction studies in the early stages of DM.
Methods
Forty-eight patients with early diagnosed (<5 years) type 2 DM and 17 healthy controls were evaluated. Of the patients with DM, 26 had neuropathic pain and 22 were asymptomatic. TPD and electrophysiological evaluations was obtained for all subjects.
Results
Nerve conduction studies in patients showed findings related to both demyelination and axonal damage. Patients with neuropathic pain had higher TPD values on the plantar surface of the foot and both groups of DM patients had higher TPD values on the outer lateral malleolus compared with the control group (P < 0.05). There was a correlation between TPD and axonal damage in patients with neuropathic pain (P < 0.05). In patients without neuropathic pain, there was a correlation between TPD values and distal latencies of motor or sensory nerves (P < 0.05). In the control group, only third digit TPD values were related to the distal motor latency of the median nerve (P < 0.05).
Conclusion
In conclusion, the TPD method is a less painful, practical, costeffective, and more easily applicable method that was completed in less timethan nerve conduction studies. Higher TPD values in the lower extremities indicate nerve damage in patients. These findings suggest that increased TPD values can easily determine neuropathy starting in the early stages of diabetes in patients with DM.
摘要
背景
糖尿病是多发性神经病变最常见的病因之一。本研究的目的是在处于早期阶段的糖尿病患者中比较测定两点辨别力（two-point discrimination, TPD）与神经传导研究。
方法
评估了48名早期（< 5年）诊断的2型糖尿病患者以及17名健康对照者。在糖尿病患者中，26名患者有神经性疼痛，22名患者无症状。所有的受试者都要进行TPD与电生理学评估。
结果
患者的神经传导研究结果显示与脱髓鞘以及轴突损害都有关系。与对照组相比较，有神经性疼痛的患者足底面的TPD值更高，并且两组糖尿病患者外踝面的TPD值都更高（P < 0.05）。在有神经性疼痛的患者中，TPD与轴突损害具有相关性（P < 0.05）。在没有神经性疼痛的患者中，TPD值与运动或者感觉神经的远端潜伏期具有相关性（P < 0.05）。在对照组中，只有第三指的TPD值与正中神经的远端运动潜伏期具有相关性（P < 0.05）。
结论
总之，与神经传导研究相比较，测定TPD的方法是一种痛苦少、成本效益高、更容易施行的方法，并且可以在更短的时间内完成。患者下肢TPD值更高意味着神经损害。这些研究结果提示，在处于早期阶段的糖尿病患者中，从升高的TPD值可以很容易地判定是否有神经病变。
16 citations
TL;DR: Sensory changes after tongue reduction by the Harada-Enomoto method for macroglossia in a 20-year-old woman with Beckwith-Wiedemann syndrome are reported.
Abstract: We report sensory changes after tongue reduction by the Harada-Enomoto method for macroglossia in a 20-year-old woman with Beckwith-Wiedemann syndrome. Sensory tests were performed before surgery and 1 week and 2 months after surgery. We assessed the static tactile threshold, vibration sense, static 2-point discrimination, pain threshold, and taste. No sensory loss of any category tested was observed after tongue reduction.
14 citations
TL;DR: There was marked, significant postoperative improvement of mean touch pressure 1-point threshold, compared with preoperative values, for medial calcaneal, medial plantar, and lateral plantar nerves in both non-diabetic and diabetic patients.
13 citations
Additional excerpts
...The 2-point discrimination test may measure different properties of the foot than other tests [50]....
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References
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TL;DR: The spatial distribution of densities supports the idea that the RA and SA I units account for spatial acuity in psychophysical tests, which is known to increase in distal direction along the hand.
Abstract: 1. Single unit impulses were recorded with percutaneously inserted tungsten needle electrodes from the median nerve in conscious human subjects. 2. A sample of 334 low threshold mechanoreceptive units innervating the glabrous skin area of the hand were studied. In accordance with earlier investigations, the units were separated into four groups on the basis of their adaptation and receptive field properties: RA, PC, SA I and SA II units. 3. The locations of the receptive fields of individual units were determined and the relative unit densities within various skin regions were calculated. The over-all density was found to increase in the proximo-distal direction. There was a slight increase from the palm to the main part of the finger and an abrupt increase from the main part of the finger to the finger tip. The relative densities in these three regions were 1, 1.6, 4.2. 4. The differences in over-all density were essentially accounted for by the two types of units characterized by small and well defined receptive fields, the RA and SA I units, whereas the PC and SA II units were almost evenly distributed over the whole glabrous skin area. 5. The spatial distribution of densities supports the idea that the RA and SA I units account for spatial acuity in psychophysical tests. This capacity is known to increase in distal direction along the hand. 6. On the basis of histological data regarding the number of myelinated fibres in the median nerve, a model of the absolute unit density was proposed. It was estimated that the density of low threshold mechanoreceptive units at the finger tip is as high as 241 u./cm2, whereas in the palm it is only 58 u./cm2.
1,148 citations
"Correlation between two-point discr..." refers methods in this paper
...Two-point discrimination The TPD test was originally used for innervations density test of afferent Þ bers.[14] Discriminating the two anatomical points by varying the distance between the two prong points measures the degree of sensation loss and detects progressive loss of sensation in the foot....
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TL;DR: Outcomes deteriorated with increasing grade and stage of wounds when measured using the University of Texas Wound Classification System and a significant overall trend toward increased prevalence of amputations was seen.
Abstract: OBJECTIVE To validate a wound classification instrument that includes assessment of depth, infection, and ischemia based on the eventual outcome of the wound. RESEARCH DESIGN AND METHODS We evaluated the medical records of 360 diabetic patients presenting for care of foot wounds at a multidisciplinary tertiary care foot clinic. As per protocol, all patients had a standardized evaluation to assess wound depth, sensory neuropathy, vascular insufficiency, and infection. Patients were assessed at 6 months after their initial evaluation to see whether an amputation had been performed. RESULTS There was a significant overall trend toward increased prevalence of amputations as wounds increased in both depth (χ 2 trend = 143.1, P 2 trend = 91.0, P P 2 = 31.5, odds ratio (OR) = 11.1, CI = 4.0–30.3). Patients with infection and ischemia were nearly 90 times more likely to receive a midfoot or higher amputation compared with patients in less advanced wound stages (76.5 vs. 3.5%, P 2 = 133.5, OR = 89.6, CI = 25–316). CONCLUSIONS Outcomes deteriorated with increasing grade and stage of wounds when measured using the University of Texas Wound Classification System.
982 citations
TL;DR: It is concluded that simple bedside investigations, such as measurement of the VPT alone, may be useful in identifying those patients at risk of foot ulceration, and foot pressure studies may then be used in such patients as a predictive and management aid by determining specific areas under the foot that are prone to ulcers.
Abstract: The pressures and loads under the feet during walking have been compared in three groups of 41 patients each, using a microprocessor-controlled optical system. Group A consisted of patients with diabetic neuropathy, group B of non-neuropathic diabetic patients, and group C of nondiabetic controls. Thirteen patients in group A had a history of neuropathic foot ulceration. Other investigations in the diabetic patients included motor conduction velocity (MCV) in the median and peroneal nerves, vibration perception threshold (VPT) in the great toes, the valsalva response (VR), skin resistance (SR), and the ankle pressure index (API). Fifty-one percent of neuropathic feet had abnormally high pressures underneath the metatarsal heads compared with 17% of the diabetic controls and 7% of nondiabetic subjects. All those feet with previous ulceration had abnormally high pressures at the ulcer sites. Of the other investigations, the VPT correlated most significantly with the presence of foot ulceration. In addition, a low median and peroneal nerve MCV, an abnormal VR, a high API, and the absence of sweating all correlated with the presence of foot ulceration. We therefore conclude that simple bedside investigations, such as measurement of the VPT alone, may be useful in identifying those patients at risk of foot ulceration. Foot pressure studies may then be used in such patients as a predictive and management aid by determining specific areas under the foot that are prone to ulceration.
411 citations
"Correlation between two-point discr..." refers background in this paper
...Boulton et al,[4] Patil et al[6] and Prabhu et al,[7] have deÞ ned peak foot pressures and shown that the loss of protective sensation is the cause for plantar ulcers in diabetic neuropathy....
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...The latter group is at risk of ulceration.[4] SWMF is less useful in screening the loss of protective sensation beyond the risk factor....
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...[5] Boulton et al,[4] Patil et al[6] and Prabhu et al,[7] have deÞ ned peak foot pressures and shown that the loss of protective sensation is the cause for plantar ulcers in diabetic neuropathy....
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TL;DR: The plantar pressure distributions for a large heterogeneous sample of feet were collected during barefoot standing using a capacitance mat and showed that the heel carried 60%, the midfoot 8%, and the forefoot 28% of the weightbearing load.
Abstract: The plantar pressure distributions for a large heterogeneous sample of feet (N = 107) were collected during barefoot standing using a capacitance mat. From these data, the function of the foot during standing was characterized. Peak pressures under the heel (139 kPa) were, on average, 2.6 times greater than forefoot pressures (53 kPa). Forefoot peak pressures were usually located under the second or third metatarsal heads. No significant relationship was found between body weight and the magnitude of peak pressure. The concepts of a transverse arch at the level of the metatarsal heads and a "tripod" theory of load distribution were not substantiated by this study. Load distribution analysis showed that the heel carried 60%, the midfoot 8%, and the forefoot 28% of the weightbearing load. The toes were only minimally involved in the weightbearing process. Examples of unusual distributions are shown; finally, a checklist is provided to aid the clinician in evaluating plantar pressure findings.
369 citations
TL;DR: The "moving two-point discrimination test" is shown to be a simple, quick, and valid diagnostic tool in nerve compression syndromes and nerve lacerations and an accurate prognosticator and monitor during sensory reeducation following nerve repair.
Abstract: As the Weber test evaluates the slowly adapting fiber-receptor system (constant touch), the "moving two-point discrimination test" evaluates the innervation density of the quickly adapting fiber-receptor system which mediates the perception of touch stimuli moving across the hand. Results with this test in 39 hands used as controls and in 63 patients with nerve injuries show it to be a simple, quick, and valid diagnostic tool in nerve compression syndromes and nerve lacerations and an accurate prognosticator and monitor during sensory reeducation following nerve repair.
287 citations
"Correlation between two-point discr..." refers background in this paper
...The precise physiological mechanisms that sub serve TPD itself remain poorly elucidated,[21,23] but may be said to be independent of skin compliance and pressure distribution....
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