The impact of traumatic spinal cord injury on structural integrity, cortical reorganization and ensuing disability is variable and may depend on a dynamic interaction between the severity of local damage and the capacity of the brain for plastic reorganization. We investigated trauma-induced anatomical changes in the spinal cord and brain, and explored their relationship to functional changes in sensorimotor cortex. Structural changes were assessed using cross-sectional cord area, voxel-based morphometry and voxel-based cortical thickness of T1-weighted images in 10 subjects with cervical spinal cord injury and 16 controls. Cortical activation in response to right-sided (i) handgrip; and (ii) median and tibial nerve stimulation were assessed using functional magnetic resonance imaging. Regression analyses explored associations between cord area, grey and white matter volume, cortical activations and thickness, and disability. Subjects with spinal cord injury had impaired upper and lower limb function bilaterally, a 30% reduced cord area, smaller white matter volume in the pyramids and left cerebellar peduncle, and smaller grey matter volume and cortical thinning in the leg area of the primary motor and sensory cortex compared with controls. Functional magnetic resonance imaging revealed increased activation in the left primary motor cortex leg area during handgrip and the left primary sensory cortex face area during median nerve stimulation in subjects with spinal cord injury compared with controls, but no increased activation following tibial nerve stimulation. A smaller cervical cord area was associated with impaired upper limb function and increased activations with handgrip and median nerve stimulation, but reduced activations with tibial nerve stimulation. Increased sensory deficits were associated with increased activations in the left primary sensory cortex face area due to median nerve stimulation. In conclusion, spinal cord injury leads to cord atrophy, cortical atrophy of primary motor and sensory cortex, and cortical reorganization of the sensorimotor system. The degree of cortical reorganization is predicted by spinal atrophy and is associated with significant disability.

Knowledge of how changes in bladder volume and the urge to void affect brain activity is important for understanding brain mechanisms that control urinary continence and micturition. This study used PET to evaluate brain activity associated with different levels of passive bladder filling and the urge to void. Eleven healthy male subjects (three left- and eight right-handed) aged 19-54 years were catheterized and the bladder filled retrogradely per urethra. Twelve PET scans were obtained during two repetitions of each of six bladder volumes, with the subjects rating their perception of urge to void prior to and after each scan. Increased brain activity related to increasing bladder volume was seen in the periaqueductal grey matter (PAG), in the midline pons, in the mid-cingulate cortex and bilaterally in the frontal lobe area. Increased brain activity relating to decreased urge to void was seen in a different portion of the cingulate cortex, in premotor cortex and in the hypothalamus. Both activation patterns were predominantly bilaterally symmetric and none of the effects could be attributed to the presence of the catheter. However, in some subjects, mostly those reporting intrusive sensations from the urethral catheter, there was a discrepancy between filling volume and urge so that they reported high urge with low volumes. As this 'mismatch' decreased, activation increased bilaterally in the somatosensory cortex. Our findings support the hypothesis that the PAG receives information about bladder fullness and relays this information to areas involved in the control of bladder storage. Our results also show that the network of brain regions involved in modulating the perception of the urge to void is distinct from that associated with the appreciation of bladder fullness.

OBJECTIVE To review the concept of urinary urgency and its practical measurement in clinical trials, and advance the hypothesis that while urge is experienced by normal people, urgency is always pathological. METHODS According to the International Continence Society (ICS) definition, urgency is the primary symptom of the overactive bladder (OAB) syndrome, but in clinical trials there are inconsistencies in both the definition and assessment of urgency. We searched the PubMed and BIOSIS databases for publications and abstracts related to the clinical assessment of urgency in patients with OAB. RESULTS The differentiation of urgency from the normal physiological desire to void is discussed. In clinical studies of OAB, urgency has been measured both qualitatively and quantitatively. Existing qualitative assessment scales for urgency are deficient in accuracy, validation or both, and are largely inconsistent with the currently accepted ICS definition of urgency. The quantitative assessment of urgency by diary entry has been validated and may be the most accurate, reproducible and clinically meaningful method available for measuring this variable. CONCLUSION Based on the existing ICS definition of urgency as ‘a compelling desire to pass urine that is difficult to defer’, the concept of qualitative assessment of urgency may be flawed.

We report on the clinical outcome and satisfaction survey of long-term suprapubic catheterisation in patients with neuropathic bladder dysfunction. Between early 1988 and later 1995, 185 suprapubic catheters were inserted under direct cystoscopic vision. Anticholinergic therapy was given to all patients with signi®cant detrusor hyper-re¯exia; the catheters clamped daily for two hours and changed every six weeks. Ultrasonography and assessment of the serum creatinine were used to assess the upper renal tracts, and the results of the pre-and post-catheter video-cystometrography was used to evaluate bladder morphology, cystometric capacity, maximum detrusor pressure and the presence of vesico-ureteric re¯ux. There were equivalent numbers of males and females. The follow-up ranges from 3 ± 68 months. Following catheterisation, there was a 50% reduction in the average maximum detrusor pressure, bladder morphology improved in 85% of the cases; the bladder capacity and upper renal tracts remained unchanged. Vesico-ureteric re¯ux was abolished in 33% of the cases. Complaints were common consisting of recurrent catheter blockage, persistent urinary leakage and recurrent urinary tract infections. There was a 2.7% incidence of small bowel injury with one fatality. However, the general level of satisfaction was high. It is concluded that suprapubic catheterisation is an e ective and well tolerated method of management in selected patients with neuropathic bladder dysfunction for whom only major surgery would otherwise provide a solution to incontinence. We are encouraged to ®nd preservation of renal function with maintained bladder volumes and reduced maximum detrusor pressures thus justifying the policy of catheter clamping and anti-cholinergic therapy in the presence of signi®cant detrusor hyper-re¯exia. However, even in expert hands this procedure is not without hazards.

An electronic interface for recording and stimulating nerves that innervate the bladder helps to restore normal bladder function in rats with spinal cord injury.

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Study design: Cross-sectional study. Objectives: (1) To assess the relationship between bladder management methods and the healthrelated quality of life (HRQL) in patients with spinal cord injury (SCI). (2) To identify any correlation between the two questionnaires used to assess the quality of life (one validated for SCI and one validated for bladder symptoms). Setting: Spinal Cord Injury Centre, Royal National Orthopaedic Hospital, Middlesex, UK. Methods: This study is based on two questionnaires with results collected from 142 people with SCI. The two questionnaires were based on information from the Short-Form 36-Item Health Survey (SF-36) and the King's Health Questionnaire and included demographic characteristics, bladder management methods and the frequency of incontinence. Results: There is a moderate correlation between the results of the SF-36 and the King's Health Questionnaire. Only 21% SCI patients report normal voiding without any other form of bladder management. The type of bladder management may influence the HRQL in patients with SCI. Clean intermittent catheterization by attendant, indwelling transurethral catheterization and indwelling suprapubic catheterization are the three groups with the worst mental status. In addition, the frequency of incontinence is a strong influence on HRQL. Conclusions:The results of this study may provide a general baseline HRQL for patients with SCI. Our findings show the relationships between bladder management methods and quality of life in patients with SCI. In addition, the impact of incontinence on quality of life was also confirmed.

Functional imaging studies, using blood oxygen level-dependent signals, have demonstrated cortical reorganization of forearm muscle maps towards the denervated leg area following spinal cord injury (SCI). The extent of cortical reorganization was predicted by spinal atrophy. We therefore expected to see a similar shift in the motor output of corticospinal projections of the forearm towards more denervated lower body parts in volunteers with cervical injury. Therefore, we used magnetic resonance imaging-navigated transcranial magnetic stimulation (TMS) to non-invasively measure changes in cortical map reorganization of a forearm muscle in the primary motor cortex (M1) following human SCI. We recruited volunteers with chronic cervical injuries resulting in bilateral upper and lower motor impairment and severe cervical atrophy and healthy control participants. All participants underwent a T1-weighted anatomical scan prior to the TMS experiment. The motor thresholds of the extensor digitorum communis muscle (EDC) were defined, and its cortical muscle representation was mapped. The centre of gravity (CoG), the cortical silent period (CSP) and active motor thresholds (AMTs) were measured. Regression analysis was used to investigate relationships between trauma-related anatomical changes and TMS parameters. SCI participants had increased AMTs (P = 0.01) and increased CSP duration (P = 0.01). The CoG of the EDC motor-evoked potential map was located more posteriorly towards the anatomical hand representation of M1 in SCI participants than in controls (P = 0.03). Crucially, cord atrophy was negatively associated with AMT and CSP duration (r(2) ≥ 0.26, P < 0.05). In conclusion, greater spinal cord atrophy predicts changes at the cortical level that lead to reduced excitability and increased inhibition. Therefore, cortical forearm motor representations may reorganize towards the intrinsic hand motor representation to maximize output to muscles of the impaired forearm following SCI.