Electrical Perception Threshold Research Articles

Complex ophthalmic neurostimulation in the rehabilitation of patients with glaucomatous optic neuropathy

Glaucomatous optic neuropathy differs significantly from other known ophthalmic neuropathies due to the gradual but steady progression, irreversible course, and resistance to treatment. Despite the fact that in recent decades, retinoprotective therapy and various physiotherapeutic factors have been widely used in the treatment of ophthalmic diseases and, in particular, this pathology [1–17], it has not been possible to reduce the incidence rate so far. In this regard, there is an urgent need for further development of comprehensive rehabilitation programs to prevent the progression of the disease. Material and research methods. The study included 78 patients (102 eyes): the main group included 58 eyes with stage 1 primary open-angle glaucoma (POAG1) of 42 patients aged 56±3.1 years (16 men, 26 women), who underwent a course of complex ophthalmic neurostimulation including transcranial magnetic stimulation with a magnetic field induction of 43 mT and a pulsating frequency of 100 Hz, endonasal electrophoresis with Semax, heliox inhalation of a heated mixture of He+O2 (21), and acupuncture. There were 10 procedures of each in a combined schedule. The comparison group included 36 patients (44 eyes) with POAG1 (14 men, 22 women) aged 53±3.2 years, who underwent a course of complex ophthalmic neurostimulation including transcranial magnetic stimulation with a magnetic field induction of 43 mT and a pulsating frequency of 100 Hz, and endonasal electrophoresis with Semax. The control group included 47 eyes of 38 patients aged 50±3.9 years (18 men, 23 women), who did not undergo physiotherapy. Results. The most pronounced results in POAG1 were obtained under the influence of an extended complex of ophthalmic neurostimulation including transcranial magnetic stimulation, endonasal electrophoresis with Semax, heliox therapy, and acupuncture, which was confirmed by a significant decrease in the number of relative scotomas, a decrease in electrical perceptual threshold, an increase in P50 amplitude in PERG, and an increase in the GCC layer that persisted up to 48 weeks in most cases. Somewhat less significant results were obtained in the comparison group, with the greatest therapeutic effect for most of the studied parameters observed in terms of up to 24 weeks, while in patients who received a vitamin therapy complex, there was noted only a positive trend, the duration of which was no more than 12 weeks, followed by deterioration. Conclusion: More pronounced therapeutic results obtained in the main group are explained by the formation of the trophostimulating effect of magneto-electrotherapy, the neuroprotective effect of the drug, as well as the pronounced neurotrophic effects of heliox therapy and acupuncture.

Quantitative electrophysiological assessments as predictive markers of lower limb motor recovery after spinal cord injury: a pilot study with an adaptive trial design

Study designObservational, cohort study.Objectives(1) Determine the feasibility and relevance of assessing corticospinal, sensory, and spinal pathways early after traumatic spinal cord injury (SCI) in a rehabilitation setting. (2) Validate whether electrophysiological and magnetic resonance imaging (MRI) measures taken early after SCI could identify preserved neural pathways, which could then guide therapy.SettingIntensive functional rehabilitation hospital (IFR).MethodsFive individuals with traumatic SCI and eight controls were recruited. The lower extremity motor score (LEMS), electrical perceptual threshold (EPT) at the S2 dermatome, soleus (SOL) H-reflex, and motor evoked potentials (MEPs) in the tibialis anterior (TA) muscle were assessed during the stay in IFR and in the chronic stage (>6 months post-SCI). Control participants were only assessed once. Feasibility criteria included the absence of adverse events, adequate experimental session duration, and complete dataset gathering. The relationship between electrophysiological data collected in IFR and LEMS in the chronic phase was studied. The admission MRI was used to calculate the maximal spinal cord compression (MSCC).ResultsNo adverse events occurred, but a complete dataset could not be collected for all subjects due to set-up configuration limitations and time constraints. EPT measured at IFR correlated with LEMS in the chronic phases (r = −0.67), whereas SOL H/M ratio, H latency, MEPs and MSCC did not.ConclusionsAdjustments are necessary to implement electrophysiological assessments in an IFR setting. Combining MRI and electrophysiological measures may lead to better assessment of neuronal deficits early after SCI.

Clinical effects of intrathecal administration of expanded Wharton jelly mesenchymal stromal cells in patients with chronic complete spinal cord injury: a randomized controlled study

Background aimsSpinal cord injury (SCI) represents a devastating condition leading to severe disability related to motor, sensory and autonomic dysfunction. Stem cell transplantation is considered a potential emerging therapy to stimulate neuroplastic and neuroregenerative processes after SCI. In this clinical trial, the authors investigated the safety and clinical recovery effects of intrathecal infusion of expanded Wharton jelly mesenchymal stromal cells (WJ-MSCs) in chronic complete SCI patients. MethodsThe authors designed a randomized, double-blind, crossover, placebo-controlled, phase 1/2a clinical trial (NCT03003364). Participants were 10 patients (7 males, 3 females, age range, 25–47 years) with chronic complete SCI (American Spinal Injury Association A) at dorsal level (T3-11). Patients were randomly assigned to receive a single dose of intrathecal ex vivo-expanded WJ-MSCs (10 × 106 cells) from human umbilical cord or placebo and were then switched to the other arm at 6 months. Clinical evaluation (American Spinal Injury Association impairment scale motor and sensory score, spasticity, neuropathic pain, electrical perception and pain thresholds), lower limb motor evoked potentials (MEPs) and sensory evoked potentials (SEPs), Spinal Cord Independence Measure and World Health Organization Quality of Life Brief Version were assessed at baseline, 1 month, 3 months and 6 months after each intervention. Urodynamic studies and urinary-specific quality of life (Qualiveen questionnaire) as well as anorectal manometry, functional assessment of bowel dysfunction (Rome III diagnostic questionnaire) and severity of fecal incontinence (Wexner score) were conducted at baseline and at 6 months after each intervention. ResultsIntrathecal transplantation of WJ-MSCs was considered safe, with no significant side effects. Following MSC infusion, the authors found significant improvement in pinprick sensation in the dermatomes below the level of injury compared with placebo. Other clinically relevant effects, such as an increase in bladder maximum capacity and compliance and a decrease in bladder neurogenic hyperactivity and external sphincter dyssynergy, were observed only at the individual level. No changes in motor function, spasticity, MEPs, SEPs, bowel function, quality of life or independence measures were observed. ConclusionsIntrathecal transplantation of human umbilical cord-derived WJ-MSCs is a safe intervention. A single intrathecal infusion of WJ-MSCs in patients with chronic complete SCI induced sensory improvement in the segments adjacent to the injury site.

Combining different evaluations of sensation to assess the afferent innervation of the lower urinary tract after SCI.

Retrospective cohort study. To study a combination of three evaluations of sensation in the lower urinary tract (LUT) in patients with spinal cord injury (SCI). University Antwerp Belgium, Unicenter study. Evaluation of perineal sensation with light digital touch, reporting of filling sensation during a standardised urodynamic investigation and determination of the electrical perception threshold (EPT) were evaluated in patients with SCI. 150 individuals were included: 97 men and 53 women, mean age 46 ± 17 years. Patients had different levels and completeness of SCI, and different techniques for bladder emptying. Seventy-four patients (49%) reported sensation to touch in the perineal area. Sensation of bladder filling was reported in different patterns by 81 patients (54%). EPT was determined in 69 patients of which 50 (72%) reported sensation in different patterns. The outcome of absence/presence of sensation between the three tests differed greatly: with perineal sensation absent 53% had filling sensation (p = 0.040) and 58% positive EPT (p = 0.009). With filling sensation absent 59% had EPT sensation (not significant). Perineal sensation was strongly associated with level and completeness of SCI, while a significant association existed for filling sensations FSF, FDV, SDV and EPT in the distal urethra. Our study shows that different evaluations of sensation in the LUT of individuals with SCI complement each other. and we therefore propose combined use in the urological evaluation of patients with SCI to allow a more complete picture of the LUT sensations.

A simple method of quantifying chemotherapy-induced peripheral neuropathy using PainVision PS-2100®.

This study aimed to validate a simplified method of quantifying chemotherapy-induced peripheral neuropathy using the PainVision PS-2100® (PV) electrical perception system. We assessed patients diagnosed with epithelial ovarian cancer, fallopian tube cancer, or peritoneal cancer and were about to undergo first-time paclitaxel and carboplatin chemotherapy. Peripheral neuropathy was assessed before and after chemotherapy administration in all patients according to the National Cancer Institute-Common Terminology Criteria for Adverse Events Version 4.0 (NCI-CTCAE4.0), using a conventional assessment in combination with the PV system. The PV device comprises electrodes attached to the ulnar side of the forearm and the first joint of index fingers on both the left and right sides to measure the electrical perceptual threshold. The average of three threshold measurements was recorded for each patient. Thirty female patients (age 51.6 ± 12.2 [mean ± SD]) were included, and median number of chemotherapy drug treatments was 5 (first quartile: 4, second quartile: 5, and third quartile: 5). Twenty-seven patients (90%) reported posttreatment numbness; NCI-CTCAE4.0 perceptual anomaly grades were as follows: G1, 57 (40%); G2, 19 (13%); and G3, 7 (5%). A positive correlation was identified between right medial side PV threshold score and perceptual anomaly grade on measurements of the inner right-hand side only. Our preliminary results suggest that peripheral neuropathy may be quantified using PV. As CIPN often lowers QOL, it needs to be appropriately evaluated. Future studies with a larger patient cohort and methodological refinements to improve accuracy are warranted.

Test procedures to assess somatosensory abnormalities in individuals with neck pain: a systematic review of psychometric properties

Background: Test procedures that were developed to assess somatosensory abnormalities should possess optimal psychometric properties (PMPs) to be used in clinical practice. The aim of this systematic review was to evaluate the level of evidence for PMPs of those test procedures, administered to identify somatosensory abnormalities in individuals with neck pain.Methods: A comprehensive electronic literature search was conducted in seven databases from inception to July 2018. The Quality Appraisal for Reliability Studies (QAREL) checklist and the COSMIN tool were used to assess risk of bias of the included studies. Level of evidence was determined based on two components: the methodological quality of included studies and the quality of statistical measures of measurement properties for each testing procedure.Results: Eighteen studies related to neck pain were included. The majority of included articles were considered to be of insufficient methodological quality to ascertain the PMPs of each testing procedure investigated. However, adequate methodological studies indicated that there is moderate level of evidence for the reliability and discriminative validity of the electrical current perception threshold using the neurometer CPT/C. In addition, the hand-held digital pressure algometer (Wagner FDX-25 Greenwich, CT) has moderate evidence for the reliability and responsiveness.Conclusions: This systematic review identified that the hand-held digital pressure algometer and the neurometer has acceptable PMPs. Future research should include adequate sample size, description of the assessors, and inclusion of blinding processes. Further research with standardized protocols is recommended to investigate the predictive ability and responsiveness of reported test procedures to ensure their extended clinical utility.

GH deficiency in patients with spinal cord injury: efficacy/safety of GH replacement, a pilot study.

ObjectiveGrowth hormone (GH) was shown to stimulate proliferation, migration and survival of neural cells in animal models. GH deficiency (GHD) was reported following traumatic brain lesions; however, there are not available data in spinal cord injury (SCI) patients. The aim of the study was to evaluate (1) the frequency of GHD in chronic SCI population; (2) the efficacy/safety of GH replacement in patients with SCI and suboptimal GH secretion.Design and methodsNineteen consecutive patients with chronic thoracic complete SCI (AIS-A) were studied. Patients with low GH secretion were randomized in a double-blind, placebo-controlled study to receive either subcutaneous placebo injections or GH combined with physical therapy, for 6 months. Baseline cranial MRI, AIS motor and sensory scale, quality of life (spinal cord impact measurement) and modified Ashworth spasticity scale, quantitative sensory testing and neurophysiological exploration were assessed at baseline, 1, 3 and 6 months following treatment.ResultsThirteen had GH deficiency. Seven received GH, five placebo and one dropped out. Both groups were similar according to clinical and demographical data at baseline, except for greater GH deficiency in the GH treatment group. At 6th month, patients treated with GH showed a significant improvement in SCIM-III score and in electrical perception threshold up to the 5th level below SCI, on both sides compared to baseline.ConclusionsGHD seems to be frequent in traumatic SCI and GH replacement is safe without side effects. GH combined with physical therapy can improve quality of life of SCI patients and, strikingly, the sensory perception below lesion level.

Measurement of perception thresholds for electrical noise stimuli.

In previous research, the application of sub-threshold electrical nerve stimulation (SENS) to peripheral nerves has been shown to improve tactile sensitivity. SENS has applications in the symptomatic treatment of a wide array of conditions that result in the loss of peripheral nerve function. These include diabetes, stroke, and age related peripheral neuropathy. The technology is dependent on careful control of the amplitude of the intervention stimulation relative to the user's perception threshold. However, little is known about the factors that influence the perception threshold and whether it can be treated as a constant. Here we present a study where we applied a two alternate forced choice paradigm to determine electrical perception threshold. We investigated participant, noise frequency characteristics, electrode location, electrode type, and electrode impedance characteristics as explanatory factors for the variability seen in the threshold outcome. We find that the electrical perception threshold is dependent on the frequency characteristics of the signal applied, but varies widely without correlation to the remaining variables. It was also highly variable when re-tested under identical conditions. Our results cast doubt on the ability to treat the electrical threshold as a single value that holds constant for a particular participant and electrode placement. This finding has significant implications in SENS applications.

Time-Dependent Discrepancies between Assessments of Sensory Function after Incomplete Cervical Spinal Cord Injury.

We recently demonstrated that the electrical perceptual threshold (EPT) examination reveals spared sensory function at lower spinal segments compared with the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) examination in humans with chronic incomplete cervical spinal cord injury (SCI). Here, we investigated whether discrepancies in sensory function detected by both sensory examinations change over time after SCI. Forty-five participants with acute (<1 year), chronic (≥1-10 years), and extended-chronic (>10 years) incomplete cervical SCI and 30 control subjects were tested on dermatomes C2-T4 bilaterally. EPT values were higher in subjects with acute (2.5 ± 0.8 mA), chronic (2.2 ± 0.7 mA), or extended-chronic (2.8 ± 1.1 mA) SCI compared with controls (1.0 ± 0.1 mA). The EPT examination detected sensory impairments in spinal segments above (2.3 ± 0.9) and below (4.2 ± 2.6) the level detected by the ISNCSCI sensory examination in participants with acute and chronic SCI, respectively. Notably, both examinations detected similar levels of spared sensory function in the extended-chronic phase of SCI (0.8 ± 0.5). A negative correlation was found between differences in EPT and ISNCSCI sensory levels and time post-injury. These observations indicate that discrepancies between EPT and ISNCSCI sensory scores are time-dependent, with the EPT revealing impaired sensory function above, below, or at the same spinal segment as the ISNCSCI examination. We propose that the EPT is a sensitive tool to assess changes in sensory function over time after incomplete cervical SCI.

The Scalp Has a Lower Stratum Corneum Function with a Lower Sensory Input than Other Areas of the Skin Evaluated by the Electrical Current Perception Threshold

Many people feel frequent prickling or itching sensations on their scalp. The scalp is an atypical area of the skin since it is normally covered with thick hair and has many sebaceous glands and sweat glands. The scalp often has skin problems that can affect its sensitivity and functions. However, not much is known about stratum corneum function and the neural sensitivity of the scalp. Here we evaluated stratum corneum function and the neural sensitivity of the scalp of 47 normal male individuals in various skin conditions and compared the results to that to the forehead. The neural sensitivity was evaluated by measuring the electrical current perception threshold (CPT). The cutaneous barrier function and stratum corneum moisture-retention ability (MRA) of the scalp were significantly lower than on the forehead, even if there were some scalp problems. Depending on the increase in severity of scalp skin problems, both these skin functional properties and the CPT decreased significantly. However, regardless of its lower functional properties, scalp skin was not significantly lower than that of the forehead. Although the scalp has a low stratum corneum function compared with the forehead and has easily induced skin problems, the scalp skin has less sensitive sensory nerves, resulting in experiencing a worsening of scalp symptoms more easily.

The effect of culture on pain sensitivity.

Cross-cultural differences in pain sensitivity have been identified in pain-free subjects as well as in chronic pain patients. The aim was to assess the impact of culture on psychophysical measures using mechanical and electrical stimuli in patients with temporomandibular disorder (TMD) pain and pain-free matched controls in three cultures. This case-control study compared 122 female cases of chronic TMD pain (39 Saudis, 41 Swedes and 42 Italians) with equal numbers of age- and gender-matched TMD-free controls. Pressure pain threshold (PPT) and tolerance (PPTo) were measured over one hand and two masticatory muscles. Electrical perception threshold and electrical pain threshold (EPT) and tolerance (EPTo) were recorded between the thumb and index fingers. Italian females reported significantly lower PPT in the masseter muscle than other cultures (P < 0.001) and in the temporalis muscle than Saudis (P = 0.003). Swedes reported significantly higher PPT in the thenar muscle than other cultures (P = 0.017). Italians reported significantly lower PPTo in all muscles than Swedes (P ≤ 0.006) and in the masseter muscle than Saudis (P < 0.001). Italians reported significantly lower EPTo than other cultures (P = 0.01). Temporomandibular disorder cases, compared to TMD-free controls, reported lower PPT and PPTo in all the three muscles (P < 0.001). This study found cultural differences between groups in the PPT, PPTo and EPTo. Overall, Italian females reported the highest sensitivity to both mechanical and electrical stimulation, while Swedes reported the lowest sensitivity. Mechanical pain thresholds differed more across cultures than did electrical pain thresholds. Cultural factors may influence response to type of pain test.

Discrepancies between clinical assessments of sensory function and electrical perceptual thresholds after incomplete chronic cervical spinal cord injury.

Study DesignProspective experimental.ObjectivesTo compare sensory function as revealed by light touch and pin prick tests of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) and the electrical perceptual threshold (EPT) exams in individuals with chronic incomplete cervical spinal cord injury (SCI).SettingPittsburgh, United States.MethodsEPT was tested using cutaneous electrical stimulation (0.5 ms pulse width, 3 Hz) in 32 healthy controls and in 17 participants with SCI over key points on dermatomes C2 to T4 on each side of the body. Light touch and pin prick ISNCSCI scores were tested at the same key dermatomes in SCI participants.ResultsIn controls, EPT values were higher in older males (1.26±0.2 mA, mean±s.d.) compared with younger males (1.0±0.2 mA) and older females (0.9±0.2 mA), regardless of the dermatome and side tested. Fifteen out of seventeen SCI participants showed that the level of sensory impairment detected by the EPT was below the level detected by the ISNCSCI (mean=4.5±2.4, range 1–9). The frequency distribution of EPTs was similar to older male controls in dermatomes above but not below the ISNCSCI sensory level. The difference between EPT and ISNCSCI sensory level was negatively correlated with the time post injury.ConclusionsThe results show that, in the chronic stage of cervical SCI, the EPT reveals spared sensory function at lower (~5) spinal segments than the ISNCSCI sensory exam. It is hence found that the EPT is a sensitive tool to assess recovery of sensory function after chronic SCI.

Epicritic Sensation in Cervical Spinal Cord Injury: Diagnostic Gains Beyond Testing Light Touch

Abstract Applied as a bedside test of gross dorsal column function, the testing of light touch (LT) sensation is of high clinical value in the diagnosis of human spinal cord injury (SCI). However, the assessment of overall dorsal column deficit by testing only LT may be limited, because the dorsal column pathway conveys several large diameter afferent modalities (e.g., sensation of touch, two-point discrimination, and proprioception). Therefore, the objective of this study was to compare the epicritic sensation assessed by LT, Semmes-Weinstein monofilament (SWM), and electrical perception threshold (EPT) across cervical dermatomes (C3-C8) in individuals with cervical SCI. A multicenter cross-sectional study was performed at 6 months after cervical SCI, applying combined measures of LT, SWM, and EPT, bilaterally over predefined key sensory points (C3-C8). A total of 300 left- and right-sided dermatomes were tested for each outcome measure in 25 participants. The percentage agreement between classifications according to LT and SWM/EPT testing for all dermatomes between C3 and C8 ranged from 95.5% to 36.2%. The degree of agreement showed considerably variable κ coefficients (-0.1≥kw≤0.7) for each dermatome between C3 and C8. The additional measurements of epicritic sensation by SWM and EPT increased sensitivity by detecting and quantifying differences in sensory thresholds above, at, and below the LT level of injury. This is relevant for early clinical trials (phase 1/2), in which disclosing any biological activity of an intervention may be revealed by subtle sensory changes that might gain a clinical relevance.

A Randomized Comparison Between Ultrasound- and Fluoroscopy-Guided Third Occipital Nerve Block

Third occipital nerve block (TONB) is commonly used in the diagnosis and treatment of upper neck pain and cervicogenic headaches. Although fluoroscopy is the current imaging standard for TONB, ultrasound (US) guidance offers a promising, radiation-free alternative. In this randomized, observer-blinded trial, we compared the 2 imaging modalities. Our research hypothesis was that US guidance would result in a shorter performance time. Forty patients undergoing TONB were randomized to fluoroscopy or US guidance. A mixture of local anesthetic and radiographic contrast was injected in both groups. The primary outcome was performance time. Secondary outcomes included success rate, pain levels before and after block, area of sensory hypoesthesia, quality of the block (assessed by electrical perceptual threshold), and procedure-related complications. Ultrasound guidance was associated with a significantly shorter performance time (212.8 vs 396.5 seconds; P = 0.000) and fewer needle passes (2 vs 6; P = 0.000). Both imaging modalities, however, resulted in similar success rates (95%-100%). Furthermore, no intergroup differences were found in preblock and postblock pain scores. In both groups, TONB produced hypoesthesia that was most profound in the suboccipital region. In the fluoroscopy group, C2-C3 intra-articular spread of radiographic contrast and vascular breach were noted in 15% and 10% of patients, respectively. In contrast, no adverse events occurred with US guidance. Fluoroscopy and US guidance provide similar success rates for TONB. However, ultrasonography is associated with improved efficiency (decreased performance time, fewer needle passes).

Reliability of the electrical perceptual threshold and Semmes-Weinstein monofilament tests of cutaneous sensibility

Prospective experimental. To compare the reliability and repeatability of the electrical perceptual threshold (EPT) and Semmes-Weinstein monofilament (SWM) tests for cutaneous sensibility. EPT and SWM tests have potential as quantitative and sensitive adjuncts to the American Spinal Injuries Association (ASIA) Impairment Scale (AIS) assessment of spinal cord injury (SCI). London, UK. EPT and SWM tests were carried out on 40 neurologically healthy individuals (20 male). One examiner carried out all the tests. Each individual was examined for EPT and SWM sensitivity at ASIA key points on four dermatomes (C4, T1, T6, L4) on both sides of the body. The tests were repeated after an interval of approximately 1 week. Intra-rater reliability was determined using intra-class correlation coefficients (ICC). Repeatability was determined using the method of Bland and Altman. There were no significant differences in the mean values of EPT or SWM between assessments for any dermatome. Significant difference in mean values for both EPT and SWM were observed between some dermatomes. ICC ranged from 0.67 to 0.81 for the EPT and from 0.46 to 0.61 for the SWM. Higher ICC for the EPT compared with the SWM was again revealed when male and female subjects were assessed separately. Correlation between EPT and SWM was weak or (largely) absent. EPT has better reliability than SWM in healthy subjects. However, as both tests have the potential to add sensitivity and resolution to the AIS assessment, a further comparison of their repeatability in SCI is warranted.

Quantitative testing in spinal cord injury: overview of reliability and predictive validity

The objective of this study was to identify commonly used physiological outcome measures and summarize evidence on the reliability and predictive validity of quantitative measures used in monitoring persons with spinal cord injury (SCI). A systematic search of PubMed through January 5, 2012, was conducted to identify publications using common outcome measures in persons with SCI and for studies that were specifically designed to evaluate the reliability and predictive validity of selected quantitative measures. Quantitative measures were defined as tests that quantify sensory and motor function, such as amount of force or torque, as well as thresholds, amplitudes, and latencies of evoked potentials that might be useful in studies and monitoring of patients with SCI. Reliability studies reporting interclass correlation coefficients (ICCs) or weighted κ coefficients were considered for inclusion. Studies explicitly evaluating correlation between measures and specific functional outcomes were considered for predictive validity. From a total of 121 potentially relevant citations, 6 studies of reliability and 4 studies of predictive validity for quantitative tests met the inclusion criteria. In persons with incomplete SCI, ICCs for both interrater and intrarater reliability of electrical perceptual threshold (EPT) were ≥ 0.7 above the sensory level of SCI but were less reliable below the sensory level. Interclass correlation coefficients for interrater and intrarater reliability of the Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP) components ranged from 0.84 to 0.98. For electromyography, the ICC was consistently high for within-day tests. The overall quality of reliability of the majority of studies was poor, due to the potential for selection bias and small sample sizes. No classic validation studies were found for the selected measures, and evidence regarding the predictive validity of the measures was limited. Somatosensory evoked potentials (SSEPs) may be correlated with ambulatory capacity, as well as the Barthel Index and motor index scores, but this correlation was limited for evaluation of bladder function recovery in 3 studies that assessed the correlation between baseline or initial SSEPs and a specific clinical outcome at a later follow-up time. All studies used convenience samples and the overall sample quality was low. Evidence on the reliability and validity of the quantitative measures selected for this review is limited, and the overall quality of existing studies is poor. There is some evidence for the reliability of the EPT, dermatomal SSEPs, and the GRASSP to suggest that they may be useful in longitudinal studies of patients with SCI. There is a need for high quality studies of reliability, responsiveness, and validity for quantitative measures to monitor the level and degree of SCI.

From the age of the pyramids to the superfast world–what has changed in the management of spinal injuries?

Spinal cord injury (SCI) can be life changing and is associated with a variable prognosis. The descriptions of symptoms of the injury are as old as the pyramids, probably among the earliest case records are from the Edwin Smith Surgical papyrus that dates back to 2500‐3500 BC. In that day and age it was considered ‘an ailment not to be cured [treated]’. However, in the 21st century things are viewed differently. The quality of life, morbidity, mortality and participation in employment and sports following spinal injuries have been revolutionised by understanding the pathology and setting standards and principles of management of care pioneered by Sir Ludwig Guttmann during the second world war who established the first spinal injuries centre at Stoke Mandeville in 1944. The principles have been replicated all over the world and have led to much improved outcomes in patients with spinal injuries. The current annual incidence of spinal injuries in the UK is 10‐15 per million population. 1 A symposium was organised a tribute to the last student of Sir Ludwig Guttmann, Professor Wagih Shafik El-Masri on as his 65th birthday. This was organised by his colleagues at the Midlands Centre for Spinal Injuries, Robert Jones and Agnes Hunt Orthopaedic Hospital and attended by 150 delegates (colleagues and friends of Professor El Masri). Guest speakers were invited from various parts of the world. The forum discussed various important learning points and observations from eminent professors in the field of spinal injuries where there is a dearth of level 1 evidence in many aspects of care. This forum also discussed various research projects on the horizon. The need for improved standards of SCI training across Europe was also highlighted. Professor Hans Frankel, an eminent neurologist from Stoke Mandeville discussed his ideas and the origins of the Frankel classification which is widely used in the classification of neurological deficit in SCI. 2 The Medical Research Council (MRC) scale was ordinal only and failed to demonstrate the functional deficit. His classification eliminated observer bias by recording functional abilities, though today, the version used in day-to-day practice tends to be the ASIA scale of impairment which also includes sacral sparing on initial examination. He also opined that regular digital per rectal examination may not add more information than performing a perineal pin prick examination. He concluded that in his experience, managing spinal injuries is easy but not simple. He suggested that electrical perceptual threshold based on skin resistance is the quantitative way of measuring sensation though currently this is mainly used for research purposes. 3

Changes in Electrical Perception Threshold Within the First 6 Months After Traumatic Spinal Cord Injury

Objective. To assess the reliability of the electrical perception threshold (EPT) in healthy participants and its responsiveness in patients for 6 months after traumatic spinal cord injury (SCI). Methods. The reliability of EPT measures was assessed in 15 healthy volunteers (from C3 to S2). EPT measures were assessed in 37 patients at 1, 3, and 6 months after SCI. EPT was determined in dermatomes at, above, and below the neurological level of lesion. Reliability was quantified with an intraclass correlation coefficient (ICC) and responsiveness with the standardized response mean (SRM). Dermatomes were classified as having normal or pathological sensory perception, based on both light touch (LT) and EPT testing. The percentage of agreement between LT and EPT classifications was determined. Results. The ICCs varied considerably between dermatomes (0.00 ≤ ICC ≤ 0.86). Overall, EPTs changed little within the first 6 months after SCI, resulting in small SRM values. Agreement between classifications according to EPT or LT testing varied from 30% to 100%. The least agreement was observed in the first segment below the lesion. Conclusion. Future studies must note that the reliability of EPT differs between dermatomes in healthy participants. Furthermore, at and below the level of the lesion, spontaneous recovery of sensory perception is poor within the first 6 months after SCI. Based on subgroup analyses, if a translational trial aims to improve sensory perception around the level of the lesion, sensory-incomplete tetraplegic patients could be included. These patients show poor spontaneous recovery, and the EPT may detect subtle changes in perception.

Changes in electrical perceptual threshold in the first 6 months following spinal cord injury

ObjectivesTo investigate the use of electrical perceptual threshold (EPT) testing to follow the natural history of sensory progression after complete and incomplete acute spinal cord injury (SCI) and to compare EPT changes with the American Spinal Injuries Association (ASIA) Impairment Scale (AIS).Study DesignProspective descriptive study.MethodsASIA examination and EPT testing was performed on 17 patients (7 AIS A, 10 AIS B–D), within 1, 3, and 6 months after acute SCI. EPT assessment was carried out bilaterally at ASIA sensory points from 2 levels above the neurological level to all levels below, including the sacral segments. Comparisons of EPT values above, at, and below the SCI were made at the three time points as well as comparisons of EPT data to ASIA assessment.ResultsThere was poor agreement between lowest normal level on EPT and ASIA assessment. Over time, EPTs tended to deteriorate above and at the ASIA level in AIS A patients with modest changes below the neurological level of injury (NLI), mainly where EPTs correlated with the zone of partial preservation. Sacral sparing was detected in one patient with EPT testing, but not with ASIA assessment. AIS B–D patients showed improvement at the ASIA level and extensive changes, both improvement and deterioration, below the NLI.ConclusionEPT testing has sufficient sensitivity to detect subclinical changes in sensory function as early as the first month post–SCI, which is not apparent in ASIA examination. In particular, the testing is able to show abnormalities at and around the injury site for both complete and incomplete SCI. In addition, EPT allows for the detection and monitoring of alterations, both improvements and deterioration, in the abnormal range of sensation.

Sensitivity to change of the cutaneous electrical perceptual threshold test in longitudinal monitoring of spinal cord injury

Prospective longitudinal experimental study. The aim of this study was to assess the sensitivity to change of the electrical perceptual threshold (EPT) test during the longitudinal monitoring of neurological changes in patients with incomplete spinal cord injury (SCI). National Spinal Injuries Centre, Stoke Mandeville Hospital, Buckinghamshire Hospitals NHS Trust, Buckinghamshire, UK. Perceptual threshold to 3 Hz cutaneous electrical stimulation was measured in 11 patients with incomplete SCI at selected American Spinal Injuries Association (ASIA) sensory key points on four occasions. The first three measurements were performed within a 5-day period (baseline) and the fourth measurement (follow-up) at least 9 months later. The results were tested for statistical significance and the effect sizes were calculated. There were no significant differences between the EPT results of the three baseline assessments. When the mean baseline and follow-up EPT results were compared, there were no significant differences in EPT values above the sensory level of lesion, but a significant difference (reduction in threshold values) was found at and below the level of SCI, with medium and large effect sizes, respectively. The EPT test showed good sensitivity to change in dermatomes at and directly below the sensory level of the SCI. This makes it a potentially useful quantitative sensory instrument for detecting changes in sensory function during longitudinal monitoring of patients with SCI.