| 1. |
- Bersch, Ines, et al.
(författare)
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Electrical stimulation-a mapping system for hand dysfunction in tetraplegia
- 2018
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Ingår i: Spinal Cord. - : Springer Science and Business Media LLC. - 1362-4393 .- 1476-5624. ; 56:5, s. 516-522
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Tidskriftsartikel (refereegranskat)abstract
- Study design Retrospective data analysis Objectives To define the distribution of the motor points and excitability of the key wrist and finger actuators in order to detect upper (UMN) and lower motor neuron (LMN) lesions potentially influencing the development of a tenodesis grasp. Setting A rehabilitation centre for spinal cord injuries, Nottwil, Switzerland. Methods Forearm muscles of 32 patients with tetraplegia (AIS A-D) were tested bilaterally with electrical stimulation (ES) to differentiate whether UMN or LMN was present. For testing, a standardised mapping was developed. All patients underwent the same positioning schedule. Results Sixteen hands developed a tenodesis grasps, 24 hands showed neither shortening nor tightening of the finger flexors. Two patients developed unilateral tenodesis grasp and showed no tightening of the finger flexors on the contralateral hand. Seven patients developed tenodesis grasps symmetrically and bilaterally, whereas one maintained an essentially open hand without tightening of the finger flexors. All hands that developed a tenodesis grasp showed a LMN lesion of the M. extensor digitorum communis (EDC). The frequency of the tenodesis grasp differed significantly between the groups with and without intact reflex arc (p < 0.0001). Conclusion Surface ES may serve as a diagnostic tool to detect an UMN or LMN lesion of the key actuator muscles affecting the tenodesis grasp. These findings provide information that is essential for the choice of treatment to optimise function of the tetraplegic hand.
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| 2. |
- Bersch, Ines, et al.
(författare)
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Long-term effect of task-oriented functional electrical stimulation in chronic Guillain Barre syndrome-a single-subject study
- 2021
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Ingår i: Spinal Cord Series and Cases. - : Springer Science and Business Media LLC. - 2058-6124. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective Functional electrical stimulation (FES) can enhance motor learning of hand fine motor skills in neurological diseases with upper motoneuron lesions. Nevertheless, FES is rarely applied in patients with chronic Guillan-Barre syndrome (GBS) with preserved deep tendon reflexes allowing for stimulation via nerve. This single case report documents the results of an FES-supported, task-oriented grasp training to regain hand closure and pinch grip. Study design Single-subject repeated measures study. Setting International FES Centre (R), Swiss Paraplegic Centre Nottwil. Methods Three individually defined goals were formulated and scored by using the goal attainment scale. With a focus on these goals, FES was applied bilaterally to improve hand closure and pinch grip. Based on principles of motor learning FES was executed together with task-oriented movements. The hand closure distance (cm) between the tip of the middle finger and the palmar side of the hand was measured and the achievement of personal, predefined goals evaluated. Results After 16 weeks of daily stimulation, hand closure could be voluntarily performed. Regained opposition of the thumb to the index finger enabled improved individually defined fine motor control. Restored function remained unchanged in the follow-up at 6 months without stimulation. Conclusion Improving fine motor skills in chronic GBS with intact deep tendon reflexes was possible utilizing FES combined with task-oriented grasp training. These improvements were maintained over time indicating the combination was effective in promoting functionally meaningful motor gains.
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| 3. |
- Bersch, Ines, et al.
(författare)
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Motor Point Topography of Fundamental Grip Actuators in Tetraplegia: Implications in Nerve Transfer Surgery
- 2020
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 37:3, s. 441-447
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Tidskriftsartikel (refereegranskat)abstract
- The differentiation between an upper motoneuron (UMN) lesion and lower motoneuron (LMN) lesion of forearm muscles in patients with tetraplegia is critical for the choice of treatment strategy. Specifically, the M. pronator teres (PT), M. flexor digitorum profundus III (FDPIII), and M. flexor pollicis longus (FPL) were studied since they represent key targets in nerve transfer surgery to restore grasp function. Forearm muscles of 24 patients with tetraplegia were tested bilaterally with electrical stimulation (ES) to determine whether UMN or LMN lesion was present. For detecting and testing the nerve stimulation points, a standardized mapping was developed and clinically applied. The relationship between the anatomical segmental spinal innervation and the innervation pattern tested by ES was determined. The data of 44 arms were analyzed. For PT, 19 arms showed an intact UMN, 18 arms an UMN lesion, and seven arms partial denervation. For FDPIII, three arms demonstrated an intact UMN, 26 arms an UMN lesion, 10 arms partial denervation, and five arms denervation. For FPL, two arms presented an intact UMN, 16 arms an UMN lesion, 12 arms partial denervation, and 14 arms denervation. A total of 20.1% ES tested muscles were partially denervated. In four patients, only one arm could be tested because of surgery-related limitations. According to the level of lesion and the segmental spinal innervation, most denervated muscles were present in the patient group C6 to C8. The ES, together with the developed mapping system, is reliable and can be recommended for standardized testing in surgery and rehabilitation. It offers the possibility to detect if and to what extent UMN and LMN lesions are present for the target muscles. It allows for refined pre-operative diagnostics and prognostics in spinal cord injury neurotization surgery.
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| 4. |
- Bersch, Ines
(författare)
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Upper and Lower Motoneuron Lesions in Tetraplegia - Diagnostic and Therapeutic Implications of Electrical Stimulation
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall objective of this thesis was to improve outcomes and predictability of the treatment of upper extremity function in patients with cervical spinal cord injury and tetraplegia by advancing the diagnostic and therapeutic tools employed in upper and lower motor neuron lesions. An overview is presented of the current knowledge about the principles of electrical stimulation and its usefulness and proven effects on the upper limb. Initially a technique was developed to map the topographic distribution of the motor points of extensor and flexor forearm muscles in able-persons. The mapping system for selected muscles on the dorsal and palmar aspect of the forearm led to remarkable findings when electrical stimulation was applied to patients with cervical spinal cord injuries. One of the main findings was that flexors are noticeably more often denervated than extensors due to lower motoneuron lesions. The findings may explain the clinical observation of better functional outcome after surgical nerve transfer to extensors compared to relatively disappointing results after nerve transfer to the flexors. The continuation of the research project was an interventional study to investigate the possibility to increase the thickness and to influence the structure in denervated forearm and hand muscles by direct electrical muscle stimulation. The case series report showed that this was possible. A reasonable interpretation is that the viability of the motor end-plate pool can be maintained through direct electrical muscle stimulation and that it is likely that an early onset of stimulation improves the conditions for successful reinnervation after nerve transfer. In addition, the time between spinal cord injury and nerve transfer may be prolonged without impairing the outcome. In order to identify the effect of electrical stimulation on neuromodulation it was analysed how robotic-controlled exercises combined with functional electrical stimulation could increase the voluntary strength of movements in people with spinal cord injury. The only available system for robotically controlled training is adapted to the lower limbs and therefore this study was performed on the lower extremities. The combination of electrical stimulation and robot-controlled, voluntary initiated training increased the recruitment of motor units and muscle strength in the legs.
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| 5. |
- Bersch, Ines, et al.
(författare)
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Upper and lower motor neuron lesions in tetraplegia: implications for surgical nerve transfer to restore hand function.
- 2020
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Ingår i: Journal of applied physiology. - : American Physiological Society. - 1522-1601 .- 8750-7587. ; 129:5, s. 1214-1219
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Tidskriftsartikel (refereegranskat)abstract
- Nerve transfers (neurotizations) performed under optimal conditions can restore some voluntary control in muscles of the upper extremities in patients with tetraplegia. However, the type of motoneuron lesions in target muscles for nerve transfers influences the functional outcome. Using standardized maps of motor point topography, surface electrical stimulation reliably defines the kind and extent of motoneuron lesion in the sel,ected muscles. In a muscle with an intact lower motor motoneuron, nerve transfers can often successfully reinnervate the chosen key muscle. Conversely, in a lower motoneuron lesion, the nerve transfer outcome is less predictable. However, direct muscle stimulation appears to ameliorate the morphological precondition, a finding that necessitates new preoperative approaches to optimize reinnervation in denervated/partially denervated muscles. Therefore, understanding the impact of electrical stimulation in diagnostics, prognostics, and treatments of upper limbs in tetraplegia is critical for neurotization procedures.
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| 6. |
- Chandrasekaran, S., et al.
(författare)
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Electrical stimulation and denervated muscles after spinal cord injury
- 2020
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Ingår i: Neural Regeneration Research. - : Medknow. - 1673-5374. ; 15:8, s. 1397-1407
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Tidskriftsartikel (refereegranskat)abstract
- Spinal cord injury (SCI) population with injury below T10 or injury to the cauda equina region is characterized by denervated muscles, extensive muscle atrophy, infiltration of intramuscular fat and formation of fibrous tissue. These morphological changes may put individuals with SCI at higher risk for developing other diseases such as various cardiovascular diseases, diabetes, obesity and osteoporosis. Currently, there is no available rehabilitation intervention to rescue the muscles or restore muscle size in SCI individuals with lower motor neuron denervation. We, hereby, performed a review of the available evidence that supports the use of electrical stimulation in restoration of denervated muscle following SCI. Long pulse width stimulation (LPWS) technique is an upcoming method of stimulating denervated muscles. Our primary objective is to explore the best stimulation paradigms (stimulation parameters, stimulation technique and stimulation wave) to achieve restoration of the denervated muscle. Stimulation parameters, such as the pulse duration, need to be 100-1000 times longer than in innervated muscles to achieve desirable excitability and contraction. The use of electrical stimulation in animal and human models induces muscle hypertrophy. Findings in animal models indicate that electrical stimulation, with a combination of exercise and pharmacological interventions, have proven to be effective in improving various aspects like relative muscle weight, muscle cross sectional area, number of myelinated regenerated fibers, and restoring some level of muscle function. Human studies have shown similar outcomes, identifying the use of LPWS as an effective strategy in increasing muscle cross sectional area, the size of muscle fibers, and improving muscle function. Therefore, displaying promise is an effective future stimulation intervention. In summary, LPWS is a novel stimulation technique for denervated muscles in humans with SCI. Successful studies on LPWS of denervated muscles will help in translating this stimulation technique to the clinical level as a rehabilitation intervention after SCI.
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