Incomplete Spinal Cord Injured Patients Research Articles

Movement analysis in spinal cord injuries : Assistance in clinical decision making

For motor incomplete spinal cord injured patients, improvement of walking function is an important aim in the rehabilitation program. In specialized treatment centers, the 6‑minute walking test, the 10-meter walking test or the timed-up-and-go test are used as an assessment tool to determine walking ability, but these tests are not able to assess the quality of gait. Marker-based movement analysis can be used as areliable method to evaluate the gait pattern. This allows an objective assessment of gait quality over time or can be used to support therapy planning. The benefit of such an analysis is presented by means of two case studies.

Short Term Effects of Rhythmic Auditory Stimulation with Body Weight Supported Treadmill Training on Gait and Balance in Individuals with Incomplete Spinal Cord Injury

Background: Rhythmic auditory stimulation and body weight supported treadmill training both are standardized gait rehabilitation techniques. However there is limited literature evaluating the effect of rhythmic auditory stimulation and its combination with gait training in spinal cord injury. Aim of this study is to determine the short term effectiveness of rhythmic auditory stimulation with body weight supported treadmill training on gait and balance in individuals with incomplete Spinal Cord Injury. Method: A randomized control study design. 8 subjects with incomplete spinal cord injury who met the inclusion criteria were randomly allocated into two groups: Experimental and Control. Subjects in experimental group were given body weight supported treadmill training with rhythmic auditory stimulation. Subjects in Control Group were given Body weight supported treadmill training alone. Both the groups received conventional rehabilitation as well. Both groups received training for 30 minutes, five times a week for two weeks (10 sessions). Outcome Measures: Gait parameters i.e. cadence, velocity, step length were measured using the Biodex Gait Trainer 2TM, level of walking performance measured using Walking Index for Spinal Cord Injury II, and balance was evaluated using Prokin 252NTM , Berg Balance Scale, and Activity specific Balance Confidence scale. Results: No significant improvement was found on gait parameters i.e. cadence, velocity, step length which were measured using the Gait Trainer, level of walking performance measured using WISCI II, and balance which was evaluated using Prokin 252NTM , Berg Balance Scale, and Activity specific Balance Confidence scale. Conclusion: Rhythmic auditory stimulation didn’t have any positive effect on gait training in incomplete spinal cord injured patients. Further studies are warranted to explore the entrainment effects of rhythmic auditory stimulation in spinal cord injured individuals on gait rehabilitation. Keywords: Rhythmic Auditory Stimulation (RAS), Body Weight Supported Treadmill Training (BWSTT), Metronome, Incomplete spinal cord injury, Biodex Gait Trainer 2.0, Prokin 252N

Advantage in muscle activation in gait with support of body weight in spinal cord injury

Abstract Introduction: The locomotor training with body weight support has been proposed as an alternative for the rehabilitation of people with spinal cord injury, in order to develop most of the residual potential of the body. Objective: To compare the levels of muscle activation of the main muscle involved in gait during body weight-supported treadmill training and body weight-supported overground training in incomplete spinal cord injured patients. Methods: It was a prospective cross-sectional study, in which 11 incomplete injured patients were submitted to two modalities of gait with body weight support, the first one on the treadmill (two different speeds: 1 and 4km/h), and the second one with the walker on fixed floor. The electromyographical acquisition was done in the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL) and gluteus maximus (GM). Results: There was a greater muscle activation of all muscles analyzed in the treadmill training as compared to the over groundtraining, both at 4 km/h (RF: p=0.00), (VM: p=0.00), (VL: p=0.00) e (GM: p=0.00) and at 1km/h (RF: p=0.00), (VM: p=0.00), (VL: p=0.00) e (GM: p=0.00). When comparing the two modalities of treadmill training, at 4 and 1km/h, there was no statically significant difference between them (RF: p=0.36), (VM: p=1.00), (VL: p=1.00) e (GM: p=0.16). Conclusion: The gait training with body weight support is more effective in activating the muscles involved in the gait training on treadmill compared to overground training in patients with incomplete spinal cord injury.

Effectiveness of transcutaneous electrical nerve stimulation in management of neuropathic pain in patients with post traumatic incomplete spinal cord injuries

Objective:To determine the effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS) in management of neuropathic pain in post-traumatic incomplete spinal cord injury patients.Methods:A quasi-experimental study was conducted at from January 2017 to June 2017 at Paraplegic Center Hayatabad, Peshawar. Total 60 incomplete spinal cord injured patients with diagnosis of neuropathic pain were subjected to high frequency TENS of 80 HZ. One session was of 45 minutes while there were two sessions per day. TENS was applied for four days in a week and all patients were followed for eight week duration. Pain intensity was measured by using VAS (Visual analogue scale).Results:Mean pain intensity on VAS at baseline was 6.45 which was decreased to 4.77 post intervention at day-1 while it was decreased to 3.48 at day-4 of week one. After application of TENS for 8 weeks, mean pain intensity was decreased to 2.80 ± 1.74. During the consecutive sessions of the TENS application, the pain intensity decreases in a linear fashion and there were significant difference (p<0.05) between pre and post treatment sessions.Conclusion:TENS is useful and safe adjuvant in spinal cord injury patients for the management of neuropathic pain.

Evaluation of the occurrence and diagnose definitions for nocturnal polyuria in spinal cord injured patients during rehabilitation

Little is known about the occurrence of nocturnal polyuria (NP) in spinal cord injured (SCI) patients and the definitions which are preferable in this population. To determine the occurrence of NP in SCI patients during in-patient rehabilitation in the Ghent University Hospital. To study the influence of different time periods (daytime, bed rest and sleep) on the accuracy of the existing diagnose definitions for NP specifically for this type of patients. Retrospective study using patient records. SCI patients during hospital-based rehabilitation between 2011 and 2014. Seventy-four SCI patients were selected and their records of frequency-volume charts (FVC) were examined, after exclusion of unreliable data, forty-seven patients were retained for the current study. Retrospective study using data from FVC of either two or three days from patients with SCI. Nocturnal urine production (NUP) and nocturnal polyuria index (NPi) were calculated. There was a significant increase in diuresis, calculated as urine production, between day time and bed rest (P=0.008) and between day time and sleep (P=0.001). All patients showed NP during a 12-hour night time period (including both bed rest and sleep) and 39 patients showed NP during the 8-hour period of sleep. There was no significant difference in mean urine production between bed rest and sleep. Prevalence of NP did not significantly differ between the complete or incomplete SCI patients or between patients with higher and lower SCI levels. This study showed that the occurrence of NP in patients with SCI is high and that it is important to consider which definitions of NP are used for diagnosis. Increase in diuresis is observed during bed rest and sleep and the diagnose is correctly estimated when nocturnal urine production definitions are used in both time periods. In accordance with what was expected, diagnose of NP was overestimated when NP index type definitions were used. It is important to be aware of the frequent-occurrence of NP in SCI patients and the impact of their daily routine to the accuracy of the diagnosis of NP. More knowledge about this topic can help to avoid incontinence caused by nocturnal polyuria.

Effect of EMG biofeedback training of gluteus maximus muscle on gait parameters in incomplete spinal cord injury

A Pretest -Posttest Experimental Design. Patients with incomplete spinal cord injury (ISCI) retain or regain the ability to walk, but due to limitations in gait parameters, walking may not be the practical method of mobility in the community. Specific muscle training plays an important role in gait training. The purpose of this study was to determine the effect of EMG Biofeedback training of gluteus maximus muscle on gait parameters in ISCI patients. Indian Spinal Injury Center, New Delhi, India. 30 incomplete spinal cord injured (ISCI) patients were included and randomly assigned to two groups. Group 1 received EMG Biofeedback (EMG BF), Traditional Rehabilitation and Gait Training. Group 2 received Traditional Rehabilitation and Gait Training. Gait parameters were measured prior to the intervention for all 30 ISCI patients. EMG Biofeedback was given specifically over gluteus maximus muscle along with traditional rehabilitation and gait training to Group 1 for 5 days/week for 4 weeks. Group 2 received traditional rehabilitation and gait training for 5 days/week for 4 weeks. The results were interpreted on the basis of: EMG amplitude, step length, walking velocity and cadence. Results showed significant difference between two groups for EMG amplitude (t = 6.06, p = 0.001), walking velocity (t = 2.12, p = 0.043), cadence (t = 1.96, p = 0.05). Step length did not show any significant difference (t = 0.66, p = 0.512). The study concluded that EMG BF when given specifically over gluteus maximus resulted in improvement of EMG amplitude and various gait parameters (walking velocity, cadence).

P 105. Efficacy of Anodal transcranial direct current stimulation in rehabilitation of motor hand function in chronic incomplete spinal cord injury may depend on sensory impairment: A pilot study

Impairment of motor function in Spinal cord injury (SCI) is associated with reduction in the excitability of motor cortical (M1) representations to muscles ( Freund et al., 2011 ), while recovery is associated with representational plasticity ( Jurkiewicz et al., 2010 ). Noninvasive brain stimulation (NBS) such as anodal transcranial direct current stimulation (atDCS) increases M1 excitability, and has beneficial effects on retention of motor skill training in both the healthy and chronic stroke survivor ( Bastani and Jaberzadeh, 2012 ). However, sensory impairment may independently predict limits of recovery of functional independence ( Kirshblum and O’Connor, 1998 ). This pilot study included incomplete tetraplegic spinal cord injured patients to examine whether the covariate of sensory impairment might account for the possible after effects of atDCS applied during simulated rehabilitation. 8 consenting right-handed outpatients at the London Spinal Cord Injury Centre, with partial impairment of non-dominant hand function (American Spinal Injury Association Impairment Scale (AIS) motor level C5-C7, C-D) were randomly allocated to ACTIVE or SHAM groups in a single-blinded RCT pilot study. Pre-assessment included standardised AIS scoring of upper limb sensory sparing (PINPRICK scoring). Subjects carried out practise of a novel, inclusive manual upper limb motor skill rehabilitation task (MSRT) developed to deliver the novel Task Productivity Rate (TPR) univariate skill measure derived from direct sampling of movement time and target accuracy. 45 min continuous, repetitive MSRT training was applied from naïve baseline state on 3 consecutive days, with follow-up measures 7 days afterwards, during the first 20 min of which received either 20 min ACTIVE anodal tDCS (1 mA, 0.029 mA/cm 2 ) or a SHAM dosage to the non-dominant M1. TPR was obtained from the first 15 min of practise in each session. Repeated measures ANOVA with covariate of PINPRICK scoring as measure of sensory impairment (ANCOVA) were applied to normalised data, with independent t -tests at the follow-up session. The ACTIVE group retained a mean TPR improvement of 42% compared to 7% by SHAM which showed a non-significant trend to benefit of ACTIVE stimulation at follow-up t (6) = 2.24, p = 0.066. ANCOVA revealed significant ( p < 0.05) main effect of ACTIVE stimulation F (1,5) = 12.9, interaction with practise time ( F (3,15) = 3.4, and between-groups effect at follow-up t (6) = 3.16, p = 0.025, r = 0.625. PINPRICK was a significant independent factor F (1,5) = 6.9, which remained stable over time F (3,15) = 0.97, p = 0.43. The independent factors did not interact (confirmatory ANCOVA F (1,4) = 0.52, p = 0.5). Adjunctive application of atDCS to M1 during rehabilitation may have imparted a lasting benefit compared to rehabilitation activity alone. But the covariate of sensory impairment (Pinprick score) independently modulated skill learning and retention scores. Because atDCS did not mitigate the negative effects of sensory impairment on skill acquisition, it is possible that atDCS boosts recovery of motor activation via un-masking of existing M1 connections rather than enhancing motor memory formation necessary for skills uptake (Reis and Fritsch, 2011) .

Kinematic modelling of a robotic gait device for early rehabilitation of walking

Rehabilitation of walking is an essential element in the treatment of incomplete spinal cord injured (SCI) patients. During the early post injury period, patients find it challenging to practice upright walking. Simulating stepping movements in a supine posture may be easier and promote earlier rehabilitation. A robotic orthotic device for early intervention in spinal cord injury that does not require the patient to be in an upright posture has been modelled. The model comprises a two-bar mechanical system that is configured and powered to provide limb kinematics that approximate normal overground walking. The modelling work has been based on gait analysis performed on healthy subjects walking at 50 per cent, 75 per cent, and 100 per cent of normal cadence. Simulated angles of hip, knee, and ankle joints show a comparable range of motion (ROM) to the experimental walking data measured in healthy subjects. The model provides operating parameters for a prospective recumbent gait orthosis that could be used in early walking rehabilitation of incomplete SCI patients.

Sacral Neuromodulation in Children With Urinary and Fecal Incontinence: A Multicenter, Open Label, Randomized, Crossover Study

The clinical benefit of sacral neuromodulation is unclear due to the paucity of randomized trial data. The purpose of this study was to evaluate sacral neuromodulation for management of urinary and fecal incontinence in a pediatric population. This multicenter, open label, randomized, crossover study included children older than 5 years. After trial stimulation of the S3 root a neuromodulator (InterStim) was implanted on the S3 foramen. Clinical examinations, voiding and bowel diaries, and urodynamic and manometric evaluations were performed at the beginning (t1) and end (t2) of the first period, and at the beginning (t3) and end (t4) of the second period. A total of 33 patients (24 boys) with a mean +/- SD age of 12.22 +/- 5.09 years were randomized. Etiologies were mainly of neurological origin. Incontinence was mixed urinary and fecal in 19 cases, urinary only in 9 and fecal only in 5. Cystometric bladder capacity increased during sacral neuromodulation (delta +24.27 ml vs -37.45 ml, p = 0.01). There was no significant change in other urodynamic or manometric parameters. Overall positive response rate was more than 75% for urinary (81%) and bowel (78%) function. Crossover analysis indicated that sacral neuromodulation is more effective than conservative treatment for both types of incontinence (p = 0.001). In a pediatric population sacral neuromodulation is effective for bladder and bowel dysfunction and should be considered before irreversible surgery.

Effectiveness of robot-assisted gait training in persons with spinal cord injury: A systematic review

To assess the quality of current evidence as to the effectiveness of robot-assisted gait training in spinal cord injured patients, focusing on walking ability and performance. A search was conducted in MEDLINE, Web of Knowledge, Cochrane Library, Physiotherapy Evidence Database (PEDro) and Digital Academic Repositories (DAREnet) (1990-2009). Key words included "spinal cord injury", "(robot-assisted) gait rehabilitation" and "driven gait orthosis". Articles were included when complete and incomplete adult spinal cord injured patients participated in robot-assisted gait training intervention studies. The methodological quality was rated independently by 2 researchers using "van Tulder criteria list" and "evaluation of quality of an intervention study". Descriptive analyses were performed using the Population Intervention Comparison Outcome (PICO) method. Two randomized controlled trials (mean quality score: 11.5/19) and 4 pre-experimental trials (mean quality score: 24.25 (standard deviation; SD 0.28)/48) involving 43 patients with incomplete, acute or chronic lesions between C3 and L1 were analysed. Five studies used the Lokomat and one used the LokoHelp. Although some improvements were reported related to body functions and activities, there is insufficient evidence to draw firm conclusions, due to small samples sizes, methodological flaws and heterogeneity of training procedures. There is currently no evidence that robot-assisted gait training improves walking function more than other locomotor training strategies. Well-designed randomized controlled trials are needed.

Cortical substrate of bladder control in SCI and the effect of peripheral pudendal stimulation

We investigated (i) the central representation of lower urinary tract (LUT) control and (ii–iii) the acute and short-term central neuromodulatory effect of peripheral pudendal nerve stimulation in incomplete spinal cord injured (SCI) patients using functional magnetic resonance imaging (fMRI). The urinary bladder of eight SCI patients has been passively filled and emptied using a catheter, to identify the neural substrate of bladder control (i), and with simultaneous peripheral pudendal nerve stimulation to investigate its acute central neuromodulatory effect (ii). To identify the potential effects of pudendal nerve stimulation treatment (iii), six patients underwent a 2-week training using pudendal nerve stimulation followed by another fMRI session of bladder filling. The pre- and post-training fMRI results have been compared and correlated with the patient's pre- and post-training urological status. Our results suggest that the central representation of bladder filling sensation is preserved in the subacute stage of incomplete SCI. However, compared to earlier data from healthy subjects, it shows decreased neural response in right prefrontal areas and increased in left prefrontal regions, indicating diminished inhibitory micturition control as well as, compensatory or decompensatory reorganization of bladder control. We also provide evidence for a neuromodulatory effect of acute pudendal nerve stimulation, which was most prominent in the right posterior insula, a brain region implicated in homeostatic interoception in human. Pudendal stimulation training also induced significant neuromodulation, predominantly signal increases, in the normal cortical network of bladder control. Correlations with the patient's urological status indicate that this neuromodulatory effect may reflect the clinical improvement following training.

Clinical outcome of sacral neuromodulation in incomplete spinal cord-injured patients suffering from neurogenic bowel dysfunctions

Retrospective study. Efficacy and safety of sacral neuromodulation (SNM) in incomplete spinal cord-injured patients (SCIPs) affected by chronic neurogenic bowel symptoms (NBSs). Neurourology Department. Primary to tertiary care. Retrospective non-blinded study without controls. Thirty-nine SCIPs were submitted to temporary stimulation for NBS. Permanent implantation was carried out if both their NBSs improved and the Wexner questionnaire scores were reduced by at least 50% during the first stage compared with that at baseline. Outcome measures included episodes of fecal incontinence and number of evacuations per week, as well as the Wexner score and the Short Form 36 (SF-36) Health Survey questionnaire. Twenty-three SCIPs were submitted to definitive SNM, maintaining their clinical benefits after permanent implantation with a median follow-up of 38 months. The length of time since neurological diagnosis to SNM therapy represents the only factor related to the success of the implantation, P<0.05. In subjects with constipation (12), the median number of evacuations shifted from 1.65 to 4.98 per week, whereas the Wexner score changed from 19.91 to 6.82 in the final checkup with P<0.05. In subjects with fecal incontinence (11), the median number of episodes per week in the final follow-up was 1.32 compared with 4.55 pre-SNM. The general and mental health of both groups was measured with the SF-36 questionnaire and consistently showed statistical improvement (P<0.05).Anorectal manometry showed no important variation compared with baseline. There were no major complications. SNM therapy should be considered for the treatment of NBS for select patients with incomplete spinal cord injury when conservative treatments fail.

Clinical outcome of sacral neuromodulation in incomplete spinal cord injured patients suffering from neurogenic lower urinary tract symptoms

Clinical outcome of sacral neuromodulation in incomplete spinal cord injured patients suffering from neurogenic lower urinary tract symptoms

Clinical outcome of sacral neuromodulation in incomplete spinal cord injured patients suffering from neurogenic lower urinary tract symptoms

To determine the efficacy and safety of sacral neuromodulation (SNM) in incomplete spinal cord injured (SCI) subjects affected by neurogenic lower urinary tract symptoms (NLUTS). Twenty-four SCI patients were enrolled. The individuals were divided into two groups: 13 individuals in the urinary retention category and 11 suffering from overactive bladder syndrome. All subjects underwent definitive SNM implantation (Medtronic, Inc.). Voiding symptoms were assessed using patient bladder diaries, which recorded both pre-SNM and before each follow-up (1, 3 and 6 months, and then every 6 months). Outcome measures were per 24 h: number of voids and voided volume per void for both groups; number of urinary leakages, pad use and nocturia for patients with overactive bladder syndrome; and volume per catheterization and number of catheterizations for urinary retention subjects only. Final checkups were completed by June 2008. Median follow-up was 61 months. Up to the final visit, all subjects maintained a clinical improvement of more than 50% compared with baseline. Twenty-two side effects were recorded. Four subjects with urinary retention needed a new implant in the controlateral S3 sacral root because of loss of efficacy. One patient with urinary retention developed a wound infection at the implanted pulse generator site. Our study contains the largest series of implanted SCI patients ever published. SNM is a therapy to consider in the treatment of NLUTS for partial SCI patients, even if the loss of clinical benefits for patients with retentive NLUTS must be taken into account. All adverse events were treated effectively.

Motor Control in the Human Spinal Cord

Features of the human spinal cord motor control are described using two spinal cord injury models: (i) the spinal cord completely separated from brain motor structures by accidental injury; (ii) the spinal cord receiving reduced and altered supraspinal input due to an incomplete lesion. Systematic studies using surface electrode polyelectromyography were carried out to assess skeletal muscle reflex responses to single and repetitve stimulation in a large number of subjects. In complete spinal cord injured subjects the functional integrity of three different neuronal circuits below the lesion level is demonstrated: first, simple mono- and oligosynaptic reflex arcs and polysynaptic pathways; second, propriospinal interneuron system with their cell in the gray matter and the axons in the white matter of the spinal cord conducting activity between different spinal cord segments; and third, internuncial gray matter neurons with short axons and dense neuron contact within the spinal gray matter. All of these three systems participate continuously in the generation of spinal cord reflex output activating muscles. The integration of these systems and their relative degree of excitation and set-up produces characteristic functions of motor control. In incomplete spinal cord injured patients, the implementation of brain motor control depends on the profile of residual brain descending input and its integration with the functional neuronal circuits below the lesion. Locomotor patterns result from the establishment of a new structural relationship between brain and spinal cord. The functions of this new structural relationship are expressed as an alternative, but characteristic and consistent neurocontrol. The more we know about how the brain governs spinal cord networks, the better we can describe human motor control. On the other hand such knowledge is essential for the restoration of residual functions and for the construction of new cord circuitry to expand the functions of the injured spinal cord.

Gait Impairments in a Group of Patients With Incomplete Spinal Cord Injury and Their Relevance Regarding Therapeutic Approaches Using Functional Electrical Stimulation

The purpose of this study is to determine the most important impairments affecting the gait pattern of the incomplete spinal cord injury (SCI) patient and the potential impact of their treatment. The study consists of two parts. Firstly, a survey amongst 16 professionals was done to find out the impact of the impairments in incomplete-SCI patients. Secondly, gait data from 21 individuals were analyzed to determine the most common impairments. Frequently observed and relevant impairments were: inadequate hip extension (occurrence 76%), limited hip flexion (52%), limited knee flexion (71%), excess of plantar flexion (76%), and impaired foot contact (52%). In conclusion, for gait improvement in incomplete spinal cord injured patients not only ankle movements must be treated, which is done frequently, but also hip extension/flexion and knee flexion are important for gait restoration. The impact on the gait and potential solutions of these impairments are discussed.

Magnetic brain stimulation can improve clinical outcome in incomplete spinal cord injured patients.

Preliminary longitudinal clinical trial. To test the efficacy of repetitive transcranial magnetic stimulation (rTMS) in modulating corticospinal inhibition and improving recovery in stable incomplete spinal cord injury (iSCI). National Spinal Injuries Centre, Stoke Mandeville Hospital, Bucks, UK and Division of Neuroscience, Imperial College Faculty of Medicine, Charing Cross Hospital, London, UK. Four stable iSCI patients were treated with rTMS over the occipital cortex (sham treatment) and then over the motor cortex (real treatment). Patients were assessed using electrophysiological, clinical and functional measures before treatment, during sham treatment, during the therapeutic treatment and during a 3-week follow-up period. Cortical inhibition was reduced during the treatment week. Perceptual threshold to electrical stimulation of the skin, ASIA clinical measures of motor and sensory function and time to complete a peg-board improved and remained improved into the follow-up period. In this preliminary trial, rTMS has been shown to alter cortical inhibition in iSCI and improve the clinical and functional outcome. This work was supported by the International Spinal Research Trust.

Urethral Evoked Sympathetic Skin Responses and Viscerosensory Evoked Potentials as Diagnostic Tools to Evaluate Urogenital Autonomic Afferent Innervation in Spinal Cord Injured Patients

In most spinal cord injured (SCI) patients the objective assessment of afferent neuronal pathways from the lower urinary tract and the recording of a disturbed urethral sensation and/or desire to void are still difficult. Viscerosensory evoked potentials (VSEPs) might be helpful, but they remain technically difficult to obtain and interpretation is delicate. As a new approach, sympathetic skin response (SSR) of the hand and foot were recorded after electrical stimulation of the posterior urethral mucosa. This technique should allow assessment of the integrity or deterioration of the autonomic afferent pathway. A total of 20 males and 8 females with SCI somatosensory incomplete 15, somatosensory complete 13 and 6 healthy male volunteers were prospectively examined. During urodynamic examination electrical stimulation (single square pulses of 0.2 ms, 2 to 3-fold sensory threshold, 60 mA in complete SCI patients) of the posterior urethra/bladder neck was performed using a bipolar electrode inserted into a microtip pressure catheter. SSR recordings of the right palm and sole were simultaneously taken using surface electrodes and were analyzed by an electromyography unit. Patient reports on evoked urethral sensations at individual sensory thresholds were simultaneously noted. Additionally, well-known electrophysiological measurements such as pudendal sensory evoked potential and urethral VSEP were recorded to check clinical assessed somatosensory and viscerosensory status, and to compare SSR results with these conventional methods. Electrical stimulation of the posterior urethra evoked clear urethral sensation and SSRs in normal subjects. In 14 of 15 sensory incomplete SCI patients with disturbed urethral sensation SSRs could be recorded as well. Electrically evoked urethral sensations resembled the subjective desire to void at full bladder reported by controls and patients. In 13 sensory complete SCI patients with loss of any urethral sensation SSRs could not be recorded even at maximal electrical stimulation strength. All subjects with electrically induced urethral sensation had positive evoked (supralesional) SSRs of the hand. However, none of the patients with absent urethral sensation presented SSRs. Simultaneously recorded VSEPs could not be recorded clearly in 5 patients and 2 control subjects, whereas SSRs delivered clear results in all controls and patients, matching their reports. SSR recordings above a spinal lesion level after urethral electrostimulation might provide a useful and technically simple objective diagnostic tool to assess integrity of autonomic (visceral) afferent nerves from the lower urinary tract. Somatosensory deficits are not always paralleled by viscerosensory loss and vice versa. In this study SSRs were superior to VSEPs, the latter being more difficult to record. The subjective sensations reported by subjects during stimulation could be confirmed in an objective way in 100% of cases by positive/negative SSR findings.

Dermatome Electrical Stimulation as a Therapeutic Ambulatory Aid for Incomplete Spinal Cord Injured Patients

Electrical stimulation of the L-3,4 dermatome during treadmill walking is proposed as a gait training modality in incomplete spinal cord injured patients. The dermatome stimulation proved to be efficient in diminishing the extensor tone occurring after loading of the paralyzed limb during the stance phase of walking and resulting in improved flexion of the leg during the swing phase.

Comparison of input-output patterns in the corticospinal system of normal subjects and incomplete spinal cord injured patients.

We have examined input-output patterns in the corticospinal system after incomplete spinal cord injury. The amplitude of the motor evoked potential (MEP) to transcranial magnetic stimulation (TMS) was used to study the patterns of recruitment, with increasing stimulus intensity, and facilitation, with increasing voluntary contraction, in thenar muscles of 12 patients with incomplete spinal cord injuries and 13 control subjects. The patients had all suffered spinal cord injury at a segmental level rostral to C8 and T1, the segments supplying innervation of thenar muscles. The patients showed a less pronounced increase in MEP amplitude with increasing strength of TMS compared with the controls. Specifically, at a stimulus strength of 120% threshold and above, the patients showed significantly smaller MEPs relative to the maximum ulnar nerve M-wave response than the controls. The patients also showed a less steep pattern of facilitation with voluntary drive. The MEP continued to increase up to 50% maximum voluntary contraction (MVC) whereas the controls reached a plateau around 10% MVC. The results indicate that the patients show modified corticospinal recruitment and facilitation of the motoneurone pool. We speculate that the function of the adapted corticospinal system after spinal cord injury might be to regulate and modulate drive to motoneurones originating from segmental and other descending inputs. We discuss how such a modified corticospinal system might be of functional benefit to the patients.