NA-CONTROL: a study protocol for a randomised controlled trial to compare specific outpatient rehabilitation that targets cerebral mechanisms through relearning motor control and uses self-management strategies to improve functional capability of the upper extremity, to usual care in patients with neuralgic amyotrophy

Abstract

Background Neuralgic amyotrophy (NA) is a distinct peripheral neurological disorder of the brachial plexus with a yearly incidence of 1/1000, which is characterised by acute severe upper extremity pain. Weakness of the stabilising shoulder muscles in the acute phase leads to compensatory strategies and abnormal motor control of the shoulder - scapular dyskinesia. Despite peripheral nerve recovery, scapular dyskinesia often persists, leading to debilitating residual complaints including pain and fatigue. Evidence suggests that persistent scapular dyskinesia in NA may result from maladaptive cerebral neuroplasticity, altering motor planning. Currently there is no proven effective causative treatment for the residual symptoms in NA. Moreover, the role of cerebral mechanisms in persistent scapular dyskinesia remains unclear. Methods NA-CONTROL is a single-centre, randomised controlled trial comparing specific rehabilitation to usual care in NA. The rehabilitation programme combines relearning of motor control, targeting cerebral mechanisms, with self-management strategies. Fifty patients will be included. Patients are recruited through the Radboud university medical center Nijmegen, the Netherlands. Patients with a (suspected) diagnosis of NA, with lateralized symptoms and scapular dyskinesia in the right upper extremity, who are 18 years or older and not in the acute phase can be included. The primary outcome is the Shoulder Rating Questionnaire score, which measures functional capability of the upper extremity. Secondary clinical outcomes include measures of pain, fatigue, participation, reachable workspace, muscle strength and quality of life. In addition, motor planning is assessed with first-person motor imagery and functional magnetic resonance imaging. In a sub-study the patients are compared to 25 healthy participants, to determine the involvement of cerebral mechanisms. This will enable interpretation of cerebral changes associated with the rehabilitation programme and functional impairments in NA. Discussion NA-CONTROL is the first randomised trial to investigate the effect of specific rehabilitation on residual complaints in NA. It also is the first study into the cerebral mechanisms that might underlie persistent scapular dyskinesia in NA. It thus may aid the further development of mechanism-based interventions for disturbed motor control in NA and in other peripheral neurological disorders. Trial registration ClinicalTrials.gov, NCT03441347 . Registered on 20 February 2018. Electronic supplementary material The online version of this article (10.1186/s13063-019-3556-4) contains supplementary material, which is available to authorized users.

Visuomotor processing is altered after peripheral nerve damage in neuralgic amyotrophy

“…The RCT was powered to demonstrate clinical effects of a specialized rehabilitation programme on functional capability of the upper limb in NA patients. 35 The current sample (39 NA patients, 23 healthy participants) suffices to replicate our previous behavioural finding of a significant interaction effect of GROUP × LATERALITY on ER on the same task in an independent sample of NA patients 18 (with power at 0.90 and α at 0.05, the required sample size is 14). 37 Previous fMRI studies using the same task have found differences in brain activity between patient populations and healthy participants with sample sizes similar to the current sample.…”

“…For an extensive description of the RCT see Lustenhouwer et al . 35 The study was approved by the local medical ethical committee (Medical Ethical Committee region Arnhem-Nijmegen, CMO 2017-3740) and is registered at ClinicalTrials.gov (NCT03441347).…”

“…See Lustenhouwer et al . 35 for a detailed description of the recruitment procedures and in- and exclusion criteria.…”

Cerebello-thalamic activity drives an abnormal motor network into dystonic tremor

“…We included 27 patients with dystonic tremor syndrome from the Radboud university medical centre (Radboudumc Nijmegen, 18 patients), Academic Medical Center (AMC Amsterdam, 7 patients), Maastricht University Medical Center+ (MUMC Maastricht, 1 patient) and Canisius Wilhelmina Ziekenhuis (CWZ Nijmegen, 1 patient). For comparison of grey matter volume with patients, we selected 27 healthy controls from two prior studies that best matched our dystonic tremor syndrome group on age and sex ( Nuland et al, 2020 , Lustenhouwer et al, 2019 ). The healthy controls were 61.0 ± 11.5 years old (range 34–80) and sex was distributed as in dystonic tremor syndrome patients (13 male, 14 female).…”

Cerebello-thalamic activity drives an abnormal motor network into dystonic tremor

“…We included 27 patients with dystonic tremor syndrome from the Radboud university medical centre (Radboudumc Nijmegen, 18 patients), Academic Medical Center (AMC Amsterdam, 7 patients), Maastricht University Medical Center+ (MUMC Maastricht, 1 patient) and Canisius Wilhelmina Ziekenhuis (CWZ Nijmegen, 1 patient). For comparison of grey matter volume with patients, we selected 27 healthy controls from two prior studies that best matched our dystonic tremor syndrome group on age and sex 28,29 . The healthy controls were 61.0 ± 11.5 years old (range 34-80) and sex was distributed as in dystonic tremor syndrome patients (13 male, 14 female).…”