Hans Jürgen Gerner

'Thought'--control of functional electrical stimulation to restore hand grasp in a patient with tetraplegia.

The aim of the present study was to demonstrate the first time the non-invasive restoration of hand grasp function in a tetraplegic patient by electroencephalogram (EEG)-recording and functional electrical stimulation (FES) using surface electrodes. The patient was able to generate bursts of beta oscillations in the EEG by imagination of foot movement. These beta bursts were analyzed and classified by a brain-computer interface (BCI) and the output signal used to control a FES device. The patient was able to grasp a cylinder with the paralyzed hand.

Event-related beta EEG changes during wrist movements induced by functional electrical stimulation of forearm muscles in man.

Event-related beta electroencephalographic (EEG) changes were studied during wrist movements induced by functional electrical stimulation (FES) of the appropriate forearm muscles in healthy volunteers. Active and passive hand movements were investigated as control conditions. Significant EEG changes with respect to a pre-movement period were analyzed by calculating time-frequency maps of event-related (de-)synchronization (ERD/ERS) for 32 EEG channels recorded from sensorimotor and premotor areas. Immediately after the beginning of the FES movement, a prominent ERD was found, followed by a beta ERS similar to that observed after active or passive wrist movements. Both changes were maximal over the contralateral primary hand area. The main difference between active and stimulation-induced movements was that in the latter case no ERD was detectable prior to movement-onset. These findings suggest that the sensorimotor processing during FES involves some of the processes which are also involved in voluntary hand movements.

Prevalence of rotator cuff tear in paraplegic patients compared with controls.

BACKGROUND Musculoskeletal injuries of the shoulder in paraplegic patients with long-term survival can result from overuse and/or inappropriate use of wheelchairs. The purpose of the present study was to evaluate the prevalence and risk of pathological changes in the weight-bearing shoulder girdle of paraplegic patients who have been wheelchair-dependent for more than thirty years in comparison with able-bodied volunteers. METHODS One hundred paraplegic patients were matched for sex and age with a group of 100 able-bodied volunteers. Two hundred shoulders from each group were evaluated with use of magnetic resonance imaging. Collected outcome measures included a standardized clinical examination protocol, the Constant score, and a visual analog score for pain intensity. RESULTS Shoulder function according to the Constant score was significantly worse in the paraplegic patients than in the able-bodied volunteers. Similarly, the visual analog scale pain scores were significantly worse for the paraplegic patients. Magnetic resonance imaging showed that the prevalence of rotator cuff tears in either shoulder was significantly higher in the paraplegic patients than in the able-bodied volunteers (63% compared with 15%), resulting in a tenfold higher risk of rotator cuff rupture among paraplegic patients. CONCLUSIONS The present study demonstrates that the structural and functional changes of the shoulder joint are more severe and the risk of development of shoulder girdle damage is significantly higher in individuals with long-term paraplegia than in age-matched controls.

Osteoporosis in patients with paralysis after spinal cord injury

Abstract In a cross-sectional study, 46 male patients with paralysis after spinal cord injury (average age 32 years; injuries sustained from 1 to 26 years ago; 33 Frankel A, 13 Frankel B, C, D) were examined clinically and by dual-energy X-ray absorptiometry (DEXA). Their bone mineral density (BMD) values were compared with age-related controls and correlated to clinical parameters. BMD was reduced in the proximal femur (p < 0.05) and the distal forearm (p < 0.05), but not in the lumbar spine. Demineralisation was influenced in the proximal femur (Z-score –2.95) by immobilisation after surgical treatment. Patients suffering from complete lesions had significantly lower BMD in the lumbar spine (–1.47) compared with patients with incomplete lesions (+0.02). BMD was not significantly influenced by the level of the lesion and the ambulatory status. Long-term monitoring showed significant demineralisation in the proximal femur (r = –0.36) and the distal forearm (r = –0.4), but not in the lumbar spine (r = –0.21). By correlating BMD with clinical parameters, it can be deduced that, firstly, immobilisation after surgical treatment should be reduced to a minimum; secondly, that every effort must be expended to prevent turning an incomplete into a complete lesion; and finally, that rehabilitation treatment should be lifelong.

Repeated botulinum-A toxin injections in the treatment of myelodysplastic children and patients with spinal cord injuries with neurogenic bladder dysfunction

Authors from Germany describe the use of botulinum toxin in the treatment of myelodysplastic children and found it to be safe and effective. They found that repeat treatments are as effective as the first one, with no evidence of tachyphylaxis, antibody formation or detrusor fibrosis.

Kinematics and kinetics with an adaptive ankle foot system during stair ambulation of transtibial amputees

Conventional prosthetic feet cannot adapt to specific conditions such as walking on stairs or ramps. Amputees are therefore forced to compensate their prosthetic deficits by modifying the kinematics and kinetics of their lower limbs. The Proprio-Foot (Ossur) intends to reduce these compensation mechanisms by automatically increasing dorsiflexion during stair ambulation thanks to an adaptive microprocessor-controlled ankle. The present investigation proposes to analyze the biomechanical effects of the dorsiflexion adaptation in transtibial (TT) amputees during stair ambulation. Sixteen TT amputees and sixteen healthy controls underwent conventional 3D gait analysis. Kinematics and kinetics of the lower limbs were compared during stair ascent and descent performed by patients with the prosthetic foot set to a neutral ankle angle and with an adapted dorsiflexion ankle angle of 4 degrees . Norm distance as well as minimum and maximal values of sagittal kinematics and kinetics were calculated for comparisons between patients and control subjects. For both stair ascent and descent, an improvement of the knee kinematics and kinetics could particularly be noticed on the involved side with an increase of the knee flexion and an increase of the knee moment during stance. Therefore, despite its additional weight compared to a conventional prosthetic ankle, the Proprio-Foot should be beneficial to active TT amputees whose knee musculature strength does not constitute a handicap.

Residual deformity of the spinal canal in patients with traumatic paraplegia and secondary changes of the spinal cord

Introduction: The effect of spinal deformity with posttraumatic kyphosis and stenosis of the spinal canal in producing secondary changes of the spinal cord has been discussed for quite some time. Since the advent of magnetic resonance imaging (MRI), 20–40% of patients with posttraumatic paraplegia are found to develop hydromyelia. Purpose of our study: To evaluate the influence of residual spinal deformity, defined by the extent of the posttraumatic kyphosis and stenosis, in the development of posttraumatic hydromyelia. Material and methods: Two hundred and seven cases of traumatic paraplegia with MRI follow-up were reviewed retrospectively. A minimum of 3 years duration between trauma and MRI study was required (mean 10.6 years [3.2–38.3]). For statistical analysis two groups of patients were formed: with hydromyelia and without hydromyelia. After healing of the fracture, the extent of the kyphosis and stenosis, as well as the characteristics of the paraplegia were noted. Results: We found that 53 patients had hydromyelia. A highly significant correlation was found for the extent of spinal stenosis and the amount of kyphosis. Cluster analysis indicated that patients with more than 15 degrees of posttraumatic kyphosis and more than 25% of stenosis were twice as likely to develop hydromyelia. The level of the lesion and the remaining neurological function was not proven to have any influence towards the development of hydromyelia. Conclusions: These results support the idea that chronic mechanical stress to the spinal cord increases the risk for the development of hydromyelia. Surgical reconstruction should be considered for all patients to prevent secondary changes of the spinal cord.

Dosage escalation of intravesical oxybutynin in the treatment of neurogenic bladder patients

Objective: We prospectively analyzed the dose dependent outcome and side effects of neurogenic bladder patients with intravesical application of oxybutynin at our centre. Materials and methods: We examined the data of 32 patients with neurogenic bladders and detrusor hyperreflexia. We registered clinical outcome, continence situation, side effects and urodynamic data of patients with (A) standard dosages of intravesical oxybutynin (0.3 mg/kg bodyweight per day) and (B) with increasing dosages in steps of 0.2 mg/kg bodyweight per day up to 0.9 mg/kg bodyweight per day. Results: We examined 32 patients aged 1 to 34 years, mean age 12 years. 21/32 patients became totally continent with the dosage (A). They showed a significant (P<0.01) decrease in the median max detrusor pressure (MDP) and a significant (P<0.01) increase in the median compliance and the median age adjusted bladder capacity (AABC). Eleven out of 32 patients remained incontinent under this dosage (A). Their median MDP, their median compliance and their median AABC remained nearly unchanged. Seven out of 11 incontinent patients under dosage (A) were treated efficiently with the higher dosages (B). Their median necessary dosage escalation to achieve treatment success was 0.7 mg/kg bodyweight per day (range 0.5 to 0.9 mg/kg bodyweight per day). Their median MDP was significantly (P<0.05) decreased and their median compliance and median AABC were significantly (P<0.05) increased. Four out of 11 patients remained incontinent and showed only little improvement in urodynamic data. Two out of 11 patients with the dosage escalation (B) showed side effects at a dosage of 0.9 mg/kg bodyweight per day. Conclusions: The intravesical application of oxybutynin was a well tolerated and efficacious therapy. The topical oxybutynin therapy dosage (A) was efficient in 66% of our selected patients, the escalating dosage titration (B) could increase the efficiency to 87%. Spinal Cord (2000) 38, 250–254.

The effect of early surgical treatment on recovery in patients with metastatic compression of the spinal cord

We analysed the influence of the timing of surgery (< 48 hours, group 1, 21 patients vs > 48 hours, group 2, 14 patients) on the neurological outcome and restoration of mobility in 35 incomplete tetra- and paraplegic patients with metastatic spinal-cord compression. Pain and neurological symptoms were assessed using the American Spinal Injury Association impairment scale. More improvement was found in group 1 than in group 2 when comparing the pre-operative findings with those both immediately post-operatively (p = 0.021) and those at follow-up at four to six weeks (p = 0.010). In group 1 the number of pre-operatively mobile patients increased from 17 (81%) to 19 patients (90%) whereas the number of mobile patients in group 2 changed from nine (64%) to ten (71%). These results suggest that early surgical treatment in patients with metastatic spinal-cord compression gives a better neurological outcome even in a palliative situation.

Resection of heterotopic ossification of the hip in spinal cord injured patients.

Twenty nine spinal cord injury patients were treated by resection of heterotopic ossification in 41 hips. The average follow-up period after surgery was 4.2 years. The mean time to surgery after injury was 82.1 months. The indications for surgery were seating problems, loss of function, pressure sores and pain. The average preoperative motion in flexion and extension was 21.95°, the average intraoperative motion was 94.51°. The average motion at follow-up evaluation was 82.68°. Clinical relevant recurrence occurred in three patients. Complications excluding recurrence occurred in 10 hips, including deep and superficial wound infections, fracture, aneurysm and pressure ulcer. The operation was followed by a specific regime of physiotherapy and radiation therapy.