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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.

Prospective experimental.The aim of this study was to develop a quantitative sensory test (QST) that could be used for assessing the level and the density (degree of impairment) of spinal cord injury (SCI) and for monitoring neurological changes in patients with SCI.National Spinal Injuries Centre, Stoke Mandeville Hospital, Buckinghamshire Hospitals NHS Trust, UK.Perceptual threshold to 3 Hz cutaneous electrical stimulation was measured in 30 control subjects and in 45 patients with SCI at American Spinal Injuries Association (ASIA) sensory key points for selected dermatomes between C3 and S2 bilaterally. Electrical perceptual threshold (EPT) was recorded as the lowest ascending stimulus intensity out of three tests at which the subject reported sensation. The level of SCI according to EPT results was established for right and left sides as the most caudal spinal segment at which patient's EPT was within the control range (mean +/- 2 standard deviation (SD)). The level of SCI, according to EPT, was then compared with clinical sensory level derived according to ASIA classification.In the control group, EPT depended on the dermatome tested and was lowest for T1 (1.01 +/- 0.23 mA, mean +/- SD) and highest for L5 (3.32 +/- 1.14 mA). There was strong correlation between corresponding right and left dermatomes and between repeated assessments. In the SCI group, the level of lesion according to EPT and clinical testing was the same in 43 of the 90 tests (48%). In 37 cases (41%), the EPT level was higher than the clinical level, and in 10 cases (11%), it was lower. Below the level of lesion in incomplete SCI and in the zone of partial preservation in complete SCI, the EPT values in most dermatomes were raised compared with the control group.EPT is a simple, reproducible QST that can assess both the level and the density of SCI. It seems to add sensitivity and resolution to the standard clinical testing and could be a useful adjunct in longitudinal monitoring of patients with SCI for research purposes during natural recovery and therapeutic interventions.International Spinal Research Trust (ISRT), UK, Grant CLI001.

McColl MA, Arnold R, Charlifue S, Glass C, Savic G, Frankel H. Aging, spinal cord injury, and quality of life: structural relationships. Arch Phys Med Rehabil 2003;84:1137–44. Objective: To quantify relationships among 3 sets of factors: demographic factors, health and disability factors, and quality of life (QOL). Design: Part of a program of longitudinal research on aging and spinal cord injury (SCI) involving 3 populations: American, British, and Canadian. The present analysis uses data from the 1999 interval. Setting: The Canadian sample was derived from the member database of the Ontario and Manitoba divisions of the Canadian Paraplegic Association. The British sample was recruited from a national and a regional SCI center in England. The American sample was recruited through a hospital in Colorado. Participants: A sample of 352 participants was assembled from 4 large, well-established databases. The sample included individuals who had incurred an SCI at least 20 years earlier, were admitted to rehabilitation within 1 year of injury, and were between the ages of 15 and 55 at the time of injury. Interventions: Not applicable. Main Outcome Measures: A combination of self-completed questionnaires and interviews. Data included demographics, injury-related variables, health and disability-related factors, QOL, and perceptions about aging. Results: Using linear structural relationships modeling, we found that QOL was affected both directly and indirectly by age, health and disability problems, and perceptions of aging. Two surprising findings were as follows: those who experienced fewer disability-related problems were more likely to report a qualitative disadvantage in aging, and the younger members of the sample were more likely to report fatigue. Conclusions: Fatigue is a concern because of the relationship of fatigue with perceived temporal disadvantage in aging, health problems, and disability problems. This finding highlights the need for clinical vigilance among those just beginning to experience the effects of aging.

Study design: Longitudinal. Objectives: (1) To perform standard clinical neurological examinations and establish the pattern of clinical change with time following incomplete spinal cord injury (iSCI). (2) To establish the pattern of change in corticospinal electrophysiological function with time after iSCI. (3) To correlate clinical with electrophysiological findings. Setting: The National Spinal Injuries Centre, Stoke Mandeville Hospital, Aylesbury, UK and Imperial College School of Medicine, Charing Cross Hospital, London, UK. Methods: Neurological assessments and classification were performed according to American Spinal Injuries Association and International Medical Society of Paraplegia (ASIA/IMSOP) standards. Twenty-one patients (ages 18–72 years) with iSCI (level C2–C7, ASIA impairment grades C–D) and 10 healthy control subjects (ages 27–57 years) were studied. Electrophysiological tests of corticospinal function were carried out using transcranial magnetic stimulation (TMS) of the motor cortex and electromyographic (EMG) recordings from thenar muscles. Both tests were performed on a number of occasions, beginning 19–384 days and ending 124–1109 days post-injury, and the group data were pooled into time epochs of 50 or 100 days post-injury for analysis. Seven of the patients were studied on seven or more occasions and were also assessed individually. Results: Individual and pooled data indicated that neurological scores improved progressively and tended to stabilise by around 300 days post-injury. When the patients were first assessed, the mean latency for motor evoked potentials (MEPs) and inhibition of voluntary EMG were significantly different from control values. There was no significant change in latency on subsequent sessions for either the grouped or individual patient data. There was no correlation between clinical assessment and electrophysiological data. Conclusion: We conclude that the weakened inhibition seen following iSCI is established within a few days of the time of spinal cord trauma. We argue that reduced corticospinal inhibition may be a prerequisite for the recovery of useful motor function. Sponsorship: The work was supported by a project grant from The Wellcome Trust. Spinal Cord (2000) 38, 292–300.

STUDY DESIGN Cross-sectional clinical review. OBJECTIVES To assess the relationship between late spinal deformity in childhood onset spinal cord injury (SCI) and level of spinal cord lesion, severity of lesion, age at onset, duration of paralysis and pelvic deformities. SETTING People with spinal cord injury (onset in childhood) treated and followed up at the National Spinal Injuries Center (identified from case notes review, contacted and agreed to participate). METHOD One hundred and eighty-nine subjects satisfying study inclusion criteria (acute onset SCI before the 16th birthday) were identified by case note review of 8200 records. Eighty formed the group attending for clinical review including whole spine radiographs (AP and lateral). Clinical examination included neurological status and joint range of movements. Demographic data was recorded. RESULTS Scoliosis occurred more frequently and was more severe in those injured at a younger age, 38 degrees, compared with 24 degrees in those injured later (P

Synchronisation of motor unit discharges is commonly seen in hand muscles of normal man but is absent following neurologically complete spinal cord injury and reduced after stroke. These findings support the notion that some corticospinal inputs to motoneurones are shared and contribute to the observed synchrony of discharge. In this study we have examined motor unit discharge in hand muscles below the level of an incomplete spinal cord injury in an attempt to relate strength of synchrony to the integrity of the corticospinal tract. Eight patients with incomplete spinal cord injury (neurological level C3-C7) and eight control subjects took part in the study. The patients had sustained injury 14-191 weeks prior to the recordings and had since regained good motor function in their hands. Two concentric needle electrodes were inserted into the first dorsal interosseus muscle which subjects were instructed to contract weakly so that potentials from individual motor units could be reliably identified on both recordings. Synchrony was detected by constructing cross-correlograms between the discharges of pairs of individual motor units. The amount of synchronous firing was determined from the magnitude of any peak in the cross-correlogram, as the probability above chance (XP) of one motor unit firing with respect to the other and vice versa. The degree of synchrony was lower (P < 0.05) in the patient group (mean XP 0.06) than in the control group (mean XP 0.09). The incidence of significant synchrony was lower in the patient group (41.8 %) than in the control group (92.9 %). The mean (+/- S.E.M.) frequency of motor unit discharge was slightly lower (P < 0.05) in patients (9.7 +/- 0.4 impulses s-1) than controls (10.8 +/- 0.5 impulses s-1). The mean width of synchrony peaks was narrower (P < 0.05) in patients (11.4 +/- 1.1 ms) than controls (13.2 +/- 0.6 ms). We conclude that the weaker synchrony of motor unit discharge in incomplete spinal cord injury may reflect permanent damage to some corticospinal axons.

A study of 3178 individuals injured in Britain between 1943 and 1990 and surviving the first year post-injury was conducted to evaluate the homogeneity of mortality risk ratios within groups based on varying degrees of neurological injury level and completeness of the injury. The study shows that it is less than optimal to combine individuals into neurological groupings of C1-C4 ABC, C5-C8 ABC and T1-S5 ABC since the risk ratios are not homogeneous within these groups. Similarly, combining individuals into neurological groupings of tetraplegia complete, tetraplegia incomplete, paraplegia complete and paraplegia incomplete may not be appropriate for the same reasons. The consequence of performing a survival analysis using either of the traditional sets of groups is to dilute the risk ratios for a subset of individuals within a particular group, thereby providing less discrimination between neurological groups. Cox proportional hazards regression was employed to determine a set of neurological groupings with homogeneous risk ratios within a group while providing better differentiation between groups.

The aims of this study were to examine long-term survival in a population-based sample of spinal cord injury (SCI) survivors in Great Britain, identify risk factors contributing to deaths and explore trends in cause of death over the decades following SCI. Current survival status was successfully identified in 92.3% of the study sample. Standardised mortality ratios (SMRs) were calculated and compared with a similar USA study. Relative risk ratio analysis showed that higher mortality risk was associated with higher neurologic level and completeness of spinal cord injury, older age at injury and earlier year of injury. For the entire fifty year time period, the leading cause of death was related to the respiratory system; urinary deaths ranked second followed by heart disease related deaths, but patterns in causes of death changed over time. In the early decades of injury, urinary deaths ranked first, heart disease deaths second and respiratory deaths third. In the last two decades of injury, respiratory deaths ranked first, heart related deaths were second, injury related deaths ranked third and urinary deaths fourth. This study also raises the question of examining alternative neurological groupings for future mortality risk analysis.

In sympathetic denervation due to primary autonomic failure, ingestion of food causes a fall in blood pressure (BP) and exacerbates postural hypotension. It is not known whether these responses occur in tetraplegics with physiologically complete cervical spinal cord transection, who also have sympathetic dysfunction because of disruption of descending spinal sympathetic pathways. We, therefore, studied the effect of a liquid meal on BP, heart rate (HR) and neurohormonal levels in tetraplegics. Paraplegics with low lesions and without sympathetic dysfunction served as controls. After food ingestion, there was no fall in BP in tetraplegics or in controls. HR did not change in either group. After fund, plasma noradrenaline was unchanged in tetraplegics, but rose in controls, while plasma renin activity (PRA) rose in tetraplegics but not in controls. The fall in BP and rise in HR on head-up tilt after the meal in tetraplegics was similar to that before the meal. There was no change in PRA following pre-prandial tilt in either group; post-prandial tilt raised levels in the tetraplegics, unlike in controls. Thus there is considerable variance in the responses to food between tetraplegics and paraplegic controls, and even greater differences when compared with published data in other autonomic disorders with sympathetic dysfunction; this may relate to the site and the nature of the sympathetic lesion and the ability to activate compensatory mechanisms.

One hundred and fifty three patients who had sustained a spinal cord injury more than 20 years previously were assessed neurologically and by MRI scanning of their spinal cords. The spinal cord pathologies shown were, in order of prevalence, extended atrophy, malacia, syrinx, cyst, disruption and tethering. There was no relationship between the prevalence of any type of pathology and the degree of spinal canal compromise or angulation of the spine adjacent to the level of injury. Neurological changes after initial neurological stabilisation were seen only in patients with extended atrophy, malacia or a syrinx, not in those with only a cyst or cord disruption. Tethering is always associated with other lesion(s). Longer syrinxes were more likely to have associated neurological changes than shorter ones. The most common neurological change was pain.

Study design: Preliminary longitudinal clinical trial. Objectives: To test the efficacy of repetitive transcranial magnetic stimulation (rTMS) in modulating corticospinal inhibition and improving recovery in stable incomplete spinal cord injury (iSCI). Setting: National Spinal Injuries Centre, Stoke Mandeville Hospital, Bucks, UK and Division of Neuroscience, Imperial College Faculty of Medicine, Charing Cross Hospital, London, UK. Methods: 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. Results: 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. Conclusion: In this preliminary trial, rTMS has been shown to alter cortical inhibition in iSCI and improve the clinical and functional outcome. Sponsorship: This work was supported by the International Spinal Research Trust.

Study design: Case report of two subjects. Objective: Charcot joints of the spine as a cause of Autonomic Dysreflexia in spinal cord lesions. Setting: Stoke Mandeville Hospital, UK. Method: Two patients with long standing spinal cord lesions developed symptoms of headaches and sweating associated with sitting up and transfers. In both cases no other cause was found to account for Autonomic Dysreflexia. Result: Charcot Joints of the spine below the level of injury were demonstrated in both cases and symptoms resolved with prolonged bed rest. Conclusion: As care of spinally injured patients continues to improve, they live longer and lead a more active lifestyle, it is expected that the incidence and prevalence of Charcot's joints will increase. Therefore the knowledge and heightened awareness of this entity, early diagnosis and detection with plain X-rays for urinary surveillance, may reduce the morbidity in spinal cord injured patients.

INTRODUCTION This report summarizes preliminary findings of three quantitative sensory tests (QSTs) that were evaluated as part of the International Spinal Research Trust (ISRT) Clinical Initiative study. ISRT commissioned this work in preparation for future clinical trials of new spinal cord injury (SCI) interventions. The wider Clinical Initiative study assesses numerous clinical and neurophysiological tests of motor, sensory, and autonomic function that could be used for monitoring the efficacy of new therapeutic interventions. The ISRT Clinical Initiative has a few specific requirements. Firstly, to minimize functional loss to the patient in case of any neurological deterioration, ISRT anticipates that the first clinical trials of spinal cord repair sponsored by them will be conducted in patients with thoracic lesions. Therefore, the newly developed tests must be applicable in the thoracic region, for which SCI diagnosis currently relies mainly on clinical sensory testing. Secondly, the first interventions are expected to produce only minor improvements and possibly over a few spinal segments only; therefore, the newly developed tests must be able to detect these small changes. The tests presented here were developed with these requirements in mind, although they can be used in patients with any level and type of injury. An overall progress review of the ISRT Clinical Initiative study was presented in the ISRT lecture at the International Spinal Cord Society's Annual Scientific Meeting in Beijing, China (October 2003) and was published in 2004 by Ellaway et al. [1]. The present article includes three of the sensory tests discussed in Ellaway et al. [1] and provides additional data acquired since that publication. However, at the time this article was prepared, the ISRT Clinical Initiative study was still ongoing and final results were unavailable. Hence, all the results reported here should be treated as preliminary. Once complete, final results will be submitted for publication as separate articles in peer-reviewed journals. The three tests discussed in this article are QSTs that assess the perceptual thresholds (PTs) (lowest stimulus intensity that a subject can perceive) for three types of stimulation: electrical, vibration, and thermal. All three stimulation types had been used previously for assessing sensory function, mainly in peripheral neuropathies [2-6], radiculopathies [7-8], and brachial plexus lesions [9]. Some QSTs have been used in patients with incomplete SCI [10-12]. For this study, the techniques were adapted to suit patients with SCI of any level, including thoracic, and of any impairment grade. Between them, the three QSTs were expected to include both of the sensory modalities tested in clinical examination (i.e., pinprick and light touch); thermal thresholds would predominantly test spinothalamic function, vibration threshold would test posterior column function, and electrical threshold would test both sensory functions. METHODS AND PRELIMINARY RESULTS The ISRT Clinical Initiative study was approved by the Aylesbury Vale Local Research Ethics Committee. Control subjects and patients with SCI were given a written information sheet and a verbal explanation of all the procedures. Written consent was obtained from all subjects. For each of the three tests (electrical, vibration, and thermal PTs), normative values and reproducibility of the technique were established in control subjects before performing the test in the patients with SCI. Wherever possible, stimuli were applied over American Spinal Injury Association (ASIA) sensory key points or, at least, within ASIA dermatomes (Figure 1). All patients also had a clinical neurological examination and classification performed according to ASIA standards [13-14] so that the QST results could be correlated with clinical sensory examination results. Consistent with ASIA standards, clinical sensory level was determined separately for the right and left sides of the body and defined as the most caudal spinal segment with normal sensory function for both sensory modalities (i. …

Prospective observational.To examine inter-rater reliability of motor and sensory examinations performed according to American Spinal Injury Association (ASIA) standards.National Spinal Injuries Centre, Stoke Mandeville Hospital, Buckinghamshire Hospitals NHS Trust, UK.Results of ASIA motor and sensory examinations performed by two experienced examiners on 45 patients with spinal cord injury (SCI) were compared.Total ASIA scores showed very strong correlation between the two examiners, with Pearson correlation coefficients and intraclass correlation coefficients exceeding 0.96, P0.01 for total motor, light touch and pin prick scores. The agreement for individual muscle testing of the 10 ASIA key muscles showed substantial agreement for majority of muscles, with the weighted Kappa coefficient range 0.649-0.993, P0.05. The overall agreement in assignment of manual muscle testing grades (0-5) was 82% on the right and 84% on the left, with the strongest agreement for grade '0' and the weakest for grade '3'. The unweighted Kappa coefficient for agreement in motor and sensory levels ranged from 0.68 to 0.78 (P0.01). There was no difference in ASIA impairment grades derived from the two examiners' results.Our study results showed very good levels of agreement in ASIA clinical examinations between two experienced examiners. The established degree of variability due to inter-rater differences should be taken into account in study design of clinical trials with more than one assessor..

Patients can often recover good motor function in muscles below an incomplete spinal cord injury. Within a few days of injury natural processes lead to down-regulation of inhibitory pathways within the motor cortex than can be demonstrated electrophysiologically. We believe that this natural change might encourage motor recovery by allowing an increased excitability of surviving descending corticospinal neurones. Repetitive transcranial magnetic stimulation (rTMS) can produce similar changes in corticospinal inhibition in normal uninjured individuals, albeit rather short-lasting. In this preliminary study we have delivered a sham rTMS over one week followed by another week of real treatment to four stable incomplete spinal cord injury patients who already showed reduced inhibition compared with controls. Intracortical inhibition was further reduced during the week of treatment but recovered basal levels within the three-week follow-up period. Longer-term improvements were seen in the clinical scores for both motor and sensory function, perceptual threshold to electrical stimulation of the skin and the time taken to complete a standard peg-board test. Although the measurable electrophysiological effects of rTMS are short-lived it would appear that functional recovery persists for at least three weeks after the treatment. Spinal cord injury patients might be more susceptible to the plastic cortical changes evoked by rTMS than non-injured individuals. This preliminary study provides promising data on which to base a larger investigation with the aim of substantiating the use of rTMS as a tool for routine use in rehabilitation.

Clinical practice and scientific research may soon lead to treatments designed to repair spinal cord injury. Repair is likely to be partial in the first trials, extending only one or two segments below the original injury. Furthermore, treatments that are becoming available are likely to be applied to the thoracic spinal cord to minimise loss of function resulting from damage to surviving connections. These provisos have prompted research into the improvement of clinical and physiological tests designed (1) to determine the level and density of a spinal cord injury, (2) to provide reliable monitoring of recovery over one or two spinal cord segments, and (3) to provide indices of function provided by thoracic spinal root innervation, presently largely ignored in assessment of spinal cord injury. This article reviews progress of the Clinical Initiative, sponsored by the International Spinal Research Trust, to advance the clinical and physiological tests of sensory, motor and autonomic function needed to achieve these aims.

STUDY DESIGN: A retrospective clinical observational study was conducted. OBJECTIVE: To assess the relation of spinal fracture type and its magnitude of distortion to subsequent long-term development of late spinal deformity in childhood onset spinal cord injury. SUMMARY OF BACKGROUND DATA: In this study, 76 adults who sustained spinal cord injury during childhood were examined clinically and radiographically alongside a retrospective review of case notes and radiographs. METHODS: The nature of the spinal injury and the progression of its displacement were defined from radiographs taken immediately after injury, then at 4 months and at 1 year. Eventual adult spinal deformity was defined from standardized erect long-plate radiographs. Scoliosis, kyphosis, and lordosis were measured using Cobb's method. RESULTS: There was no statistically significant difference in the severity of scoliosis, kyphosis, or lordosis between traumatic and nontraumatic injuries, nor between patients with and those without radiologically visible bony injury. Of the 14 patients with traumatic thoracic and lumbar injuries who had undergone no surgical intervention, 10 (71%) showed development of major scoliotic curves that did not include the fracture site. The patients with no angular displacement at the fracture site after 1 year went on to experience the development of more severe scoliosis (mean, 66 degrees) than those who had displaced fractures (mean, 38 degrees). In five, a low kyphotic curve and a compensatory lordosis above it developed. CONCLUSIONS: There is no evidence that the bony injury to the vertebral column itself in the child with spinal cord injury influences the development of late scoliosis or lordosis, but it may influence any eventual kyphosis.

Objectives: The sympathetic skin response (SSR) is a technique to assess the sympathetic cholinergic pathways, and it can be used to study the central sympathetic pathways in spinal cord injury (SCI). This study investigated the capacity of the isolated spinal cord to generate an SSR, and determined the relation between SSR, levels of spinal cord lesion, and supraspinal connections. Methods: Palmar and plantar SSR to peripheral nerve electrical stimulation (median or supraorbital nerve above the lesion, and peroneal nerve below the lesion) were recorded in 29 patients with SCI at various neurological levels and in 10 healthy control subjects. Results: In complete SCI at any neurological level, SSR was absent below the lesion. Palmar SSR to median nerve stimuli was absent in complete SCI with level of lesion above T6. Plantar SSR was absent in all patients with complete SCI at the cervical and thoracic level. In incomplete SCI, the occurrence of SSR was dependent on the preservation of supraspinal connections. For all stimulated nerves, there was no difference between recording from ipsilateral and contralateral limbs. Conclusions: No evidence was found to support the hypothesis that the spinal cord isolated from the brain stem could generate an SSR. The results indicate that supraspinal connections are necessary for the SSR, together with integrity of central sympathetic pathways of the upper thoracic segments for palmar SSR, and possibly all thoracic segments for plantar SSR.

OBJECTIVES—Motor evoked potentials (MEPs) and inhibition of voluntary contraction to transcranial magnetic stimulation (TMS) of the motor cortex have longer latencies than normal in patients with incomplete spinal cord injury (iSCI) when assessed using surface EMG. This study now examines the modulation of single motor unit discharges to TMS with the aim of improving resolution of the excitatory and inhibitory responses seen previously in surface EMG recordings. METHODS—A group of five patients with iSCI (motor level C4-C7) was compared with a group of five healthy control subjects. Single motor unit discharges were recorded with concentric needle electrodes from the first dorsal interosseus muscle during weak voluntary contraction (2%-5% maximum). TMS was applied with a 9 cm circular stimulating coil centred over the vertex. Modulation of single motor unit discharges was assessed using peristimulus time histograms (PSTHs). RESULTS—Mean (SEM) threshold (expressed as percentage of maximum stimulator output (%MSO)) for the excitatory peak (excitation) or inhibitory trough (inhibition) in the PSTHs was higher (p

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.

OBJECTIVES (1) A biochemical investigation of the motor cortex in patients with incomplete spinal cord injury and normal control subjects using proton magnetic resonance spectroscopy (MRS). (2) To relate any altered biochemistry with the physiological changes in corticospinal function seen after spinal cord injury. METHODS a group of six patients with incomplete spinal cord injury who showed good recovery of motor function were selected. The patients were compared with five healthy control subjects. Electromyographic (EMG) responses of thenar muscles to transcranial magnetic stimulation (TMS) of the motor cortex showed that inhibition of cortical output was weaker in the patients than the controls. Proton MRS data were collected from a plane at the level of the centrum semiovale. Two 4.5 cm3 voxels in the motor cortex and a third voxel in the ipsilateral occipital cortex were examined in the patients and control subjects. RESULTS The mean level of N- acetylaspartate (NAA), expressed relative to the creatine (Cr) peak (NAA/Cr), was significantly increased in the motor cortex of the patients compared with their ipsilateral occipital cortex or either cortical area in the controls. No differences between patients and controls were seen for any of the other metabolite peaks (choline (Cho), glutamate/glutamine (Glx) or the aspartate component of NAA (AspNAA)) relative to Cr. Choline relative to Cr (Cho/Cr) was higher in the motor cortex of the control subjects than in their ipsilateral occipital cortex. This difference was not present in the patients. CONCLUSIONS Raised NAA/Cr in the motor cortex of the patients probably results from increased NAA rather than a decrease in the more stable Cr. The possible relevance of a raised NAA/Cr ratio is discussed, particularly with regard to the changed corticospinal physiology and the functional recovery seen in the patients.

OBJECTIVE To investigate changes in electromyographic (EMG) responses to transcranial magnetic stimulation (TMS) of the motor cortex after incomplete spinal cord injury in humans. METHODS A group of 10 patients with incomplete spinal cord injury (motor level C3-C8) was compared with a group of 10 healthy control subjects. Surface EMG recordings were made from the thenar muscles. TMS was applied with a 9 cm circular stimulating coil centred over the vertex. The EMG responses to up to 50 magnetic stimuli were rectified and averaged. RESULTS Thresholds for compound motor evoked potentials (cMEPs) and suppression of voluntary contraction (SVC) elicited by TMS were higher (p

Previous studies have estimated that between 25% and 45% of people with spinal cord injury report severe levels of chronic pain. Few studies have examined this longitudinally. This study examines the primary pain sites, intensity and variability of perceived pain in 76 patients, 6 weeks post injury and 45 patients from the same cohort, 8 year post discharge. Demographic information reveals a close similarity with the database (40 000) from Stover and Fine's cohort (1986). Data was assessed using visual analogue scales, measures were also taken of functional independence (FIM), emotional status and coping. At 6 weeks post injury, most pain is sited in the thoracic spine area, and in the upper and lower limbs. At 1 year post discharge, most pain is reported to be in the thoracic spine area, the lumbar region and the chest. Twenty-three per cent of the 6 week group reported that the intensity of their pain was severe, whilst at 1 year, 41% of the sample complained of severe pain. Factors associated with the pain at both time points were explored using correlational analyses. The emotional, functional and psychological factors that predict pain severity were explored using multiple regression analysis. Twenty-four per cent of those reporting moderate to severe pain at 6 weeks post injury were still reporting pain at 1 year post discharge. This study examines the relative contribution of psychological factors in reported pain.

The case histories of two patients who had had a spinal cord injury (SCI) were selected by the senior author and sent to four experts in the field of SCI. Based on the 1992 American Spinal Injury Association (ASIA) and International Medical Society of Paraplegia (IMSOP) standards, the four participants plus the senior author recorded the motor and sensory scores, the ASIA impairment scale (AIS), the neurological level (NL) and the zone of partial preservation (ZPP). Several minor scoring errors occurred among the participants, especially with motor scores when key muscles could not be tested due to pain, or external immobilization devices. Difficulties with interpretation occurred with the motor levels and the ZPP for the patient with a complete injury. This exercise points to the need for all examiners of SCI patients to thoroughly familiarize themselves with the standards and to use the motor and sensory scores to arrive at a NL and ZPP. They also indicate a need to revise the standards to clarify the determination of sensory levels and how to score muscles whose strength is inhibited by pain.

Mortality, morbidity, health, functional, and psychosocial outcomes were examined in 834 individuals with long term spinal cord injuries. All were treated at one of two British spinal injury centres: the National Spinal Injuries Centre at Stoke Mandeville Hospital or the Regional Spinal Injuries Centre in Southport; all were 20 or more years post injury. Using life table techniques, median survival time was determined for the overall sample (32 years), and for various subgroups based on level and completeness of injury and age at injury. With the number of renal deaths decreasing over time, the cause of death patterns in the study group as it aged began to approximate those of the general population. Morbidity patterns were found to be associated with age, years post injury, or a combination of these factors, depending upon the particular medical complication examined. A current medical examination of 282 of the survivors revealed significant declines in functional abilities associated with the aging process. Declines with age also were found in measures of handicap and life satisfaction, but three quarters of those interviewed reported generally good health and rated their current quality of life as either good or excellent.

The electrical perceptual threshold (EPT) test complements the American Spinal Injury Association (ASIA) assessment of cutaneous sensory function by providing a quantitative assessment for each dermatome. The aim here was to establish the reliability of the EPT by examining inter- and intra-rater repeatability of test results in spinal cord injury (SCI). Twelve persons with incomplete spinal cord injury (iSCI; two stable at20 months and 10 sub-acute at9 months post-injury) and 12 control subjects took part. EPT was established at the ASIA sensory key points. A pulse of 0.5 ms in duration was applied three times per second. Threshold was determined by the method of limits. The strength of stimulation was augmented (0.1 mA.s(-1)) until the recipient reported sensation, then reduced until sensation was lost. EPT was taken as the lowest strength at which the subject reported sensation. Threshold was determined by two raters to establish intra- and inter-rater reliability. There were no significant differences in mean intra- or inter-rater EPT values at, above, or below the level of lesion (ASIA sensory level) for iSCI subjects. The intra-class correlation coefficient (ICC) was 0.56-0.80 for intra-rater and 0.52-0.91 for inter-rater classes, depending on the level tested. There was a significant correlation (Pearson's r = 0.93) between EPTs for four different dermatomes of control subjects assessed using two different types of stimulator. EPT provides an objective and quantitative measure of threshold for cutaneous sensory function. The method has good inter- and intra-rater reliability, and can be assessed using different stimulators.

This article reviews methods that have been devel- oped as part of a clinical initiative on improving outcome meas- ures for motor function assessment in subjects with spinal cord injury (SCI). Physiological motor outcome measures originally developed for limbs—transcranial magnetic stimulation (TMS) of the motor cortex to elicit motor-evoked potentials (MEPs) and mechanical stimulation to elicit spinal reflexes—have been extended to muscles of the trunk. The impetus for this develop- ment is the lack of a motor component in the American Spinal Injury Association clinical assessment for the thoracic myo- tomes. The application of TMS to the assessment of limb mus- cles is reviewed, followed by consideration of its application to the assessment of paravertebral and intercostal muscles. Spinal reflex testing of paravertebral muscles is also described. The principal markers for the thoracic SCI motor level that have emerged from this clinical initiative are (1) the threshold of MEPs in paravertebral muscles in response to TMS of the motor cortex, (2) the facilitation pattern and latency of MEPs in intercostal muscles during voluntary expiratory effort, and (3) the absence of long-latency reflex responses and the exaggeration of short-latency reflex responses in paravertebral muscles.

A postlaminectomy pseudomeningocele is a spherical, fluid-filled space with fibrous capsule lying dorsal to the thecal canal in the laminectomy opening that occasionally develops after surgery. Eight cases were found in 400 symptomatic postlaminectomy patients undergoing computed tomographic examination. The contents are of cerebrospinal fluid density and mayor may not have demonstrable communication with the subarachnoid space. Whether they are the cause of symptoms is conjectural; none of these eight patients had surgical removal.

The physiologically responses to hypoglycaemia induced by fish insulin were studied in nine tetraplegic subjects with physiological complete cervical spinal cord transection between C4 and C8. During hypoglycaemia there was a reduction in both systolic and diastolic blood pressure unlike in normal subjects. This was accompanied by a rise in heart rate. The normal rise in plasma adrenaline levels did not occur. Plasma human insulin levels were suppressed. The usual neuroglycopenic symptoms accompanying hypoglycaemia did not occur in the tetraplegics.

1. The cardiovascular and hormonal effects of intravenous saralasin (0.5, 1 and 5 μg min−1 kg−1) were assessed in nine tetraplegic patients (with complete cervical spinal cord transaction above the sympathetic outflow) and in six normal subjects. 2. In the tetraplegic patients, saralasin caused an immediate transient pressor response which was not dose-dependent and substantially greater than the pressor response in normal subjects. The pressor response in the tetraplegic patients was not accompanied by a rise in levels of plasma noradrenaline. 3. In the tetraplegic patients, after α-adrenoceptor blockade with thymoxamine (1 mg kg−1 h−1), twice the dose of intravenous noradrenaline was needed to induce the same pressor response. The pressor response to saralasin (5 μg kg−1 min−1), however, was unaffected by thymoxamine. 4. Saralasin caused minimal changes in levels of plasma renin activity and plasma aldosterone in both groups. There was no relationship between basal plasma renin activity and the pressor response in either group. 5. We therefore conclude that the immediate transient pressor response to saralasin in man is not due to central sympathetic stimulation, is unlikely to be due to peripheral sympathetic activation and is probably the result of intrinsic angiotensin II-like myotropism.

1. The effect of endogenous sympathetic stimulation (induced by urinary bladder stimulation) and intravenous infusion of noradrenaline and isoprenaline on blood pressure, heart rate and levels of plasma renin activity and plasma aldosterone were studied in six tetraplegic patients. Data from infusion studies were compared with data from six normal subjects studied in an identical manner. 2. Bladder stimulation in the tetraplegic patients caused a marked rise in blood pressure and fall in heart rate, but no change in plasma renin activity or plasma aldosterone. 3. Noradrenaline infusion resulted in an enhanced pressor response in the tetraplegic patients when compared with the normal subjects. Heart rate fell in both groups. Plasma renin activity and plasma aldosterone did not change in either group. 4. Isoprenaline infusion caused a fall in both systolic and diastolic blood pressure in the tetraplegic patients, unlike the normal subjects in whom there was a rise in systolic and a fall in diastolic blood pressure. Heart rate and plasma renin activity rose in both groups. Plasma aldosterone did not change in either group. 5. We conclude that in tetraplegic patients neither endogenous sympathetic stimulation by bladder stimulation nor infusion of noradrenaline raises plasma renin activity. Isoprenaline increases plasma renin activity to the same extent as in normal subjects. Renin release mechanisms in tetraplegic patients therefore do not appear to be hypersensitive to catecholamines. Plasma aldosterone is not influenced by any of the stimuli.

1. Plasma catecholamines, plasma renin activity, plasma aldosterone and haematocrit were measured in four subjects with physiologically complete cervical spinal cord transections, before, during and after head-up tilt to 45° for 30 min. Plasma catecholamines were measured in five normal male volunteers in the supine position and after head-up tilt to 45° for 10 min. 2. After 10 min of head-up tilt, the plasma noradrenaline rose 14% in the tetraplegic patients and 115% in the control subjects. These findings indicate a failure of sympathetic activity in response to head-up tilt in the tetraplegic patients, probably caused by interruption of pathways by which the brain normally controls sympathetic outflow. 3. In the tetraplegic patients the resting plasma renin activities were above normal, and rose more quickly and greater on head-up tilt than in published studies of normal subjects. It is likely that the renal baroreceptors are important in the control of renin release. 4. In the tetraplegic patients, there was a late rise in plasma aldosterone which was probably due to the elevation in plasma renin activity.

Eight patients with spinal cord lesions due to decompression sickness are described. The cord lesions were in the cervical cord in four cases and in the upper dorsal cord in the other four, seven patients had incomplete lesions, one had a complete lesion, all patients were spastic. The diving details and description of the onset of paralysis are given and possible pathological processes are discussed. Prophylaxis is by adequate use of decompression stops. The most satisfactory treatment is immediate recompression.

Since Sir Ludwig Guttmann introduced the comprehensive modern clinical approach to the rehabilitation of spinal cord injured patients much experience has been accumulated. Modern spinal cord injuries centres have opened throughout the world, treating mainly acute spinal cord injuries in young patients. At Stoke Mandeville Hospital we have had the opportunity to treat several spinal patients who had suffered previous neurological or orthopaedic disorders. These complicated combinations affected the rehabilitation process and the presentations show clearly different aspects of the problem.

One hundred and fifty patients with spinal cord lesions due to diving accidents were admitted to Stoke Mandeville Hospital between 1944--77. Most of the patients were young men, 65 had dived into the sea, 48 into swimming pools, 21 into rivers and 3 into lakes. Injuries due to diving into the deep end of swimming pools appear to have been eliminated in Great Britain but injuries due to diving into the shallow end of swimming pools and into the sea continue to occur. The public need further education about the dangers of diving.

We studied the haemodynamic effects of clonidine (2 micrograms/kg/iv) in 7 tetraplegics and 7 normal subjects. Measurements of blood pressure, stroke volume, cardiac output and digital (finger) skin blood flow were made before and after clonidine for 60 minutes. Blood pressure, stroke volume and cardiac output did not fall in tetraplegics, unlike normals. Resting digital skin blood flow was higher in tetraplegics and fell after clonidine. In normal subjects however, an increase in digital skin blood flow occurred after clonidine. The pressor and digital vasoconstrictor responses to bladder stimulation were attenuated after clonidine. The inability of clonidine to induce a fall in blood pressure, stroke volume, cardiac output and cause peripheral vasodilation in tetraplegics is consistent with its central sympatholytic effects. Attenuation of the responses to bladder stimulation suggest an effect on spinal sympathetic neurones.

Blood pressure, plasma catecholamines and prostaglandins during artificial erection in a male tetraplegic

Aqualung diving is practised by some paralysed sportsmen. Close cooperation between suitable disabled persons and their medical advisers is emphasised.

The sympathetic outflow emerges from the thoracic and upper lumbar seg­ ments of the spinal cord and in patients with high spinal cord lesions is dissociated from cerebral regulation. This results in disordered cardiovascular control that is influenced by the level and completeness of the lesion, in addition to other factors such as hormones that directly alter cardiovascular function or indirectly influence it by changing renal function or intravascular volume. In this review emphasis is placed on patients with complete cervical spinal cord transection above the sympathetic outflow; they form a human physiological model, in whom the afferent, central, and vagal efferent com­ ponents of the baroreflex arc are intact, but where the spinal and peripheral sympathetic nervous system is isolated (Figure 1). Other than a section on recently injured tetraplegics in spinal shock, all descriptions refer to chroni­ cally injured tetraplegics (synonomous with quadriplegics).

1. Six patients with long-standing physiologically complete cervical spinal cord lesions and two normal subjects were examined. 2. In the tetraplegic subjects, arterial blood pressure, heart rate, plasma noradrenaline and adrenaline were measured at rest and during bladder percussion, during electrical stimulation of muscles and during infusion of noradrenaline. 3. In the normal subjects arterial blood pressure and heart rate were recorded before and during noradrenaline infusion. 4. Bladder percussion and muscle stimulation caused a rise in plasma noradrenaline from a subnormal level, together with a rise in blood pressure. 5. A similar rise in blood pressure due to noradrenaline infusion occurred at a very much greater level of plasma noradrenaline. 6. It is concluded that hypertension in tetraplegic subjects who have bladder percussion or muscle stimulation, is due to sympathetic overactivity rather than adrenal medullary secretion. Findings are consistent with, but not conclusive of, supersensitivity of the blood vessels of tetraplegic subjects to noradrenaline.

Patients who are tetraplegic with cervical spinal cord transection do not appear to have cerebral control over the sympathetic nervous system. Soon after transection they are often in a state of spinal shock during which even isolated spinal cord sympathetic activity is absent. This affects, in particular, the cardiovascular system and other homeostatic mechanisms which are dependent on appropriate regulation of the vasculature, such as thermoregulation. After a few weeks isolated spinal cord activity returns but the absence of control absence of control by the brain results in sympathetic malfunction of various systems. Inappropriate inactivity therefore occurs during postural change and causes orthostatic hypotension, while over-activity, which results in the syndrome of autonomic dysreflexia and hypertension, occurs if spinal sympathetic reflexes are activated. Examples are provided of clinical effects of sympathetic malfunction in tetraplegics in relation to circulatory, thermoregulatory, pupillary, genital, gastrointestinal and urinary tract function.

The arterial blood pressure, heart rate and electrocardiograph were recorded, and plasma electrolytes, arterial blood gases and pH, and plasma catecholamines were estimated in seven patients with physiologically complete cervical spinal cord transections who needed intermittent possitive pressure ventilation (I.P.P.V.) or were undergoing urological surgery under general anaesthesia. In the tetraplegics on I.P.P.V., bradycardia, and in two patients even cardiac arrest, occurred during tracheal suction, especially in the presence of hypoxia. In one tetraplegic being anaesthetised, cardiac arrest occurred during endotracheal intubation. This reflex bradycardia and cardiac arrest appeared to be due to a vago-vagal reflex, unopposed by sympathetic activity or by the pulmonary (inflation) vagal reflex. Atropine was effective in preventing this reflex. In the tetraplegics undergoing urological surgery, severe hypertension resulting from visceral stimulation was effectively reduced by halothane. In these patients, control of arterial blood pressure with lower concentrations of halothane may also be achieved with I.P.P.V.