Factors of Cortical Plasticity in Brachial Plexus Injury

Cortical plasticity is the brain’s capability of decoding new information through growth and reorganization over our whole life spam. It is the basis for good outcomes after reinnervation and for rehabilitation of adult and obstetric brachial plexus injury. Knowledge about cortical reorganization is crucial to reconstructive surgeons and physiotherapists that aim to give their patients a reasonable prognosis. This chapter intends to present and summarize the current literature on how to detect and quantify cortical plasticity and how research on factors that influence cortical plasticity, mainly in relation to peripheral nerve and more precise brachial plexus injury progresses. Peculiarities of adult and obstetric brachial plexus injuries and their treatment are given. We present techniques that visualize and quantify cortical plasticity with focus on functional imaging like fMRI and nTMS as well as molecular aspects. Future research is needed to understand mechanisms of how molecular changes on a synaptic level of a neuron influence the macroscopic plasticity, to improve rehabilitative resources, to understand the exact prognostic value of nTMS in brachial plexus injury and to investigate the therapeutic capability of rTMS

Motor and functional outcome of selective dorsal rhizotomy in children with spastic diplegia at 12 and 24 months of follow-up

Background: Selective dorsal rhizotomy (SDR) in ambulatory children affected by cerebral palsy (CP) is a surgical treatment option to lower spasticity and thereby improve gait and ambulation. The aim of the current study is to investigate the outcome of children with respect to spasticity, muscle strength, and overall function after SDR. Methods: All children who underwent SDR via a single-level laminotomy in the time period from January 2007 to April 2015 at our center were enrolled in this study. Within a standardized evaluation process, the following was assessed routinely pre-operatively and 12 and 24 months following surgery: extent of spasticity at hip adductors and hamstrings as characterized by the Modified Ashworth Scale (MAS), maximal muscle strength as characterized by the Medical Council Research Scale (MRC), overall function regarding ambulation as characterized by the Gross Motors Function Classification System (GFMCS), and overall function as characterized by the Gross Motor Function Measure (GMFM-88). Results: Matching sets of pre- and post-operative assessments of the chosen outcome parameters were available for 109 of the 150 children who underwent SDR within the observation period. After 24 months, the MAS scores of hip adductors (n = 59) improved in 71% and 76% of children on the right and left side, respectively. In 20% and 19%, it remained unchanged and worsened in 9% and 5% of children on the right and left side, respectively (p < 0.00625). For hamstrings, the rates for the right and left sides were 81% and 79% improvement, 16% and 16% unchanged, and 4% and 5% worsened, respectively (p < 0.00625). Muscle strength of ankle dorsiflexion and knee extension significantly improved after 24 months. Overall function assessed by GMFM-88 improved significantly by 4% after 12 months (n = 77) and by 7% after 24 months (n = 56, p < 0.0001). Conclusions: The presented data underlines the benefit of SDR in a pediatric patient collective with bilateral spastic CP. The procedure resulted in an effective and permanent reduction of spasticity and improved overall function without causing relevant weakness of the lower extremities

The minimally invasive renaissance of a classic surgical method: results of the first European application of minimally invasive selective dorsal rhizotomy by T.S. Park

Hintergrund: Die selektive dorsale Rhizotomie (SDR) führt bei Patienten mit einer infantilen Zerebralparese (CP) zu einer dauerhaften Reduktion der Spastik. Sie wurde Anfang des 20. Jahrhunderts von Otfrid Foerster in Europa eingeführt. Aufgrund der von ausgeprägter Morbidität begleiteten Eingriffe wurde die Methode vorübergehend verlassen. Erst in den 60er Jahren kam es zu einer sukzessiven Modifikation durch französische und italienische Neurochirurgen. Die SDR etablierte sich schließlich in den USA als sichere und effektive Methode zur Reduktion der Spastik. Die klassische Operationstechnik mit einem multisegmentalen Zugang in mindestens 5 Höhen wurde zuletzt von T.S. Park soweit modifiziert, dass die vollständige Rhizotomie über eine monosegmentale Laminektomie sicher durchführbar ist. E.J. Haberl hat die minimal invasive Technik nach Park um die neue Zugangsmodifikation einer speziellen Laminoplastie-Technik erweitert, bei welcher der interspinosale durch einen transspinosalen Zugang ersetzt wird und damit die Integrität der dorsalen Zuggurtung der Wirbelsäule erhalten bleibt. In Europa hat sich bis heute eine historische Skepsis gegenüber der operativen Unterbrechung des spinalen Reflexbogens erhalten. Mit der Publikation der ersten Ergebnisse nach Wiedereinführung der Methode in Deutschland wollen wir zeigen, dass die SDR eine effektive Reduktion der Spastik erzielt, ohne eine Muskelschwäche zu erzeugen. Methoden: 150 Kinder unterzogen sich von 01/2007 bis 04/2015 am selbstständigen Arbeitsbereich Pädiatrische Neurochirurgie der Charité der minimal invasiven SDR nach Haberl. In dieser prospektiven, klinischen Studie erfolgten Untersuchungen durch multidisziplinäre Teams präoperativ sowie 12 und 24 Monate postoperativ. Für die Evaluation der Operationsergebnisse wurden standardisierte Untersuchungsparameter verwendet: Die Beurteilung der Spastik der unteren Extremitäten erfolgte mit Hilfe der modifizierten Ashworth Skala (MAS). Funktionelle Veränderungen wurden durch die Gross Motor Function Measure (GMFM-88) erfasst. Zusätzlich erfolgte eine manuelle Testung der maximalen Muskelkraft (MFT). Ergebnisse: Die vollständige Evaluation der MAS der Adduktoren erfolgte bei 85 bzw. 59 Patienten, der ischiocruralen Muskulatur bei 85 bzw. 58 Patienten und der Wadenmuskulatur bei 59 bzw. 36 Patienten nach 12 bzw. 24 Monaten postoperativ. Bei den Adduktoren und der ischiocruralen Muskulatur kam es 24 Monate nach SDR zu einer signifikanten (p<0,00625) Reduktion der Spastik. Die Untersuchung der MFT zeigte keine klinisch relevante Schwächung der Muskulatur. Die Dorsalextension der Sprunggelenke und die Extension der Kniegelenke zeigten signifikante (p<0,00625) Verbesserungen im Verlauf über zwei Jahre. Bei 77 bzw. 56 Patienten erfolgte eine vollständige Evaluation der GMFM-88 nach 12 bzw. 24 Monaten postoperativ. Diese zeigte eine Verbesserung um 7,17% nach 24 Monaten. Schlussfolgerung: Die minimal invasive SDR führt zu einer signifikanten Reduktion der Spastik, ohne dabei eine relevante Muskelschwäche zu erzeugen. Die Ergebnisse gehen mit einer Verbesserung der motorischen Funktion einher. Diese Ergebnisse bedürfen einer Bestätigung im Langzeitverlauf.Background: Selective dorsal rhizotomy (SDR) leads to a permanent reduction in spasticity in patients with cerebral palsy. The treatment was introduced to Europe by Otfrid Foerster at the beginning of the 20th century, but was temporarily abandoned due to high morbidity rates associated with the procedure. It was not until the 1960s that successive modifications were made by French and Italian neurosurgeons. SDR eventually established itself in the U.S.A. as a safe and effective method for the reduction of spasticity. The original operative technique, that required a multilevel approach over at least 5 segments, was finally modified by T.S. Park such that the entire rhizotomy could be carried out safely over a single-level laminectomy. E.J. Haberl further developed Park’s minimally invasive SDR with a novel technique of laminoplasty in which the interspinous approach was replaced with a transspinous approach, achieving complete restoration of the dorsal column. To this day in Europe, some historical scepticism remains about the surgical interruption of the spinal reflex arc. Our publication of initial results of a reintroduction of the method to Germany aims to contribute to the reinstatement of the surgical procedure. Methods: From January 2007 until April 2015, 150 children underwent Haberl’s minimally invasive SDR at the division of pediatric neurosurgery of the Charité in Berlin. As part of this clinical study, preoperative and postoperative (after 12 and 24 months) examinations were carried out by multidisciplinary teams. Standardised examination parameters were used for the evaluation of the surgical results: characterisation of spasticity in the lower extremities was achieved with help of the Modified Ashworth Scale (MAS). Changes in functional performance were documented against the Gross Motor Function Measure (GMFM-88). In addition, a manual testing of maximum muscle strength (MFT) was carried out. Results: At 12 and 24 months postoperatively, a complete evaluation of MAS results was produced for the following: hip adductors – 85 and 59 patients; hamstring muscles – 85 and 58 patients; plantar flexors – 59 and 36 patients, respectively. For adductors and hamstring muscles we observed a significant (p<0.00625) reduction in spasticity over the first two years. Examination of the MFT showed no clinically relevant deterioration of muscle strength. Ankle dorsiflexion and extension of the knee joint showed significant improvements over the two year period. At 12 and 24 months postoperatively, a complete evaluation of the GMFM-88 was completed for 77 and 56 patients, respectively. An improvement of 7,17% was observed after 24 months. Conclusions: Minimally invasive SDR leads to a significant reduction in spasticity without causing muscle deterioration. Our results are accompanied by an equally improvement in motor function. Future work should confirm these results over a longer time period

Peripheral nerve stimulation for the treatment of chronic knee pain

Abstract The average age of our population is increasing, resulting in a high incidence of chronic degenerative knee pathologies. Several treatment options, including surgical procedures are available to help mitigate these pathologies. However, the percentage of subjects with chronic post-surgical knee pain is still estimated at 16–20%. Neuromodulation techniques such as spinal cord stimulation and dorsal root ganglion stimulation (DRGS) are treatment options for subjects with chronic knee pain. The evidence for peripheral nerve stimulation (PNS) is minimal due to a limited number of neuromodulation systems capable of targeting the distal part of the lower limbs. This study aimed to investigate the safety and efficacy externally powered PNS systems for the treatment of chronic intractable knee pain targeting the saphenous nerve. Patients suffering from chronic intractable post-surgical knee pain received landmark-guided peripheral nerve stimulation of the branches of the saphenous nerve. All implants were performed with an externally powered PNS system to avoid lead migration as a result of cross-joint lead positions tunneling towards an Implantable Pulse Generator to the trunk. Data were collected retrospectively. Subject-reported outcome was measured via numerical rating scale values on a 10-point scale measuring pain intensity at rest and in motion. Additional data were collected for the subjects treated at the Charité location, including quality of life with the SF-36 form, quality of sleep with the Pittsburgh Sleep Quality Index and mood states with the short form of the General Depression Scale. Thirty-three patients received direct to permanent implant, landmark-guided peripheral nerve stimulation of the saphenous nerve branches. Six (18.2%) subjects reported non-sufficient initial benefit from the therapy and were explanted. Two subjects were explanted due to wound infections. The total study population reported included 25 patients. These subjects reported significant improvements related to pain, quality of life, mood quality, and quality of sleep. Additionally, subjects were able to reduce their opioid medication significantly after PNS therapy. Externally powered PNS at the saphenous nerve branches is a straightforward, selective and safe technique for patients with chronic knee pain. The landmark-guided implantation technique is less invasive than classical neuromodulation techniques such as spinal cord or DRGS and complication rates remain low. Short-term results are promising and show considerable reductions in pain scores and opioid intake. Long-term results are pending