Neuralgic Amyotrophy: Central Reorganization and Rehabilitation After Peripheral Dysfunction (NA-CONTROL)

This study evaluates the effect of a specific, multidisciplinary and personalized rehabilitation program compared to usual care, on motor control and functional disability in patients with neuralgic amyotrophy. Half of the participants will start with the 17-week specific rehabilitation program while the other half will first continue their usual care for 17 weeks, after which they will also receive the 17-week specific rehabilitation program.

Neuralgic amyotrophy (NA) is a common (incidence 1:1000) peripheral nervous system disorder caused by acute autoimmune inflammation of the brachial plexus, the nerve bundle going to the shoulder and arm. Many NA patients develop abnormal motor control of the shoulder region (i.e. scapular dyskinesia), which persists even after the peripheral nerve damage has recovered. This suggests that persistent scapular dyskinesia in NA may result from (mal)adaptive changes in the central motor system. Clinical experience shows that the specific, multidisciplinary and personalized rehabilitation program, focused on cognitive motor control can restore scapular dyskinesia in NA patients. This indicates that impairments in the central motor system likely play a role in persistent scapular dyskinesia and that specific rehabilitation may restore any alterations in central motor control. We hypothesize that the specific rehabilitation program, focused on cognitive motor control is more effective in improving functional disability than usual care and that it can reverse maladaptive changes in central motor control.

Patients in the experimental arm start the 17 week experimental intervention right after they enter the study. Patients in the second arm first continue to receive their usual care for 17 weeks, after which they also receive the experimental intervention. Both groups are assessed at baseline and after the initial 17 weeks. The second group is assessed a third time, after they have completed the 17-week experimental treatment program.

Specific, personalized, multidisciplinary rehabilitation program consisting of physical- and occupational therapy.

17-week specific and personalised rehabilitation program. The program starts with a visit to the Plexus out patient clinic in week 1. During this visit, the patient will be examined by a multidisciplinary team, consisting of a rehabilitation physician, neurologist, physical therapist and occupational therapist, which will form a rehabilitation treatment plan. This treatment plan is implemented through 4 weekly sessions in week 2-5, 2 biweekly sessions in week 6-9 and 2 monthly sessions in week 10-17 . Each treatment session involves one hour of physical- and one hour of occupational therapy.

Change in the magnitudes of mean functional Magnetic Resonance Imaging signal (Blood-oxygen-level dependent (BOLD) activity) related to motor imagery of the affected arm, quantifying changes in central motor control

Change in performance on motor imagery tasks. Performance is evaluated by means of reaction times and error rates.

Change in self-efficacy for performing energy conservation strategies assessment (SEPECSA) score from baseline

Change in maximal force exerted with the serratus anterior muscle from baseline, measured when reaching with extended arm and flexed arm

Reachable workspace is an objective measure of upper extremity impairment. Reachable workspace is quantified by the relative surface area representing the portion of the unit hemisphere that is covered by the hand movements made during a standardized movement protocol which covers cardinal movements of the shoulder

Inclusion Criteria: (Suspected) diagnosis of neuralgic amyotrophy In subacute or chronic phase of neuralgic amyotrophy (>2 months after attack onset) Right-handed Neuralgic amyotrophy predominantly present in right upper extremity Presence of scapular dyskinesia Exclusion Criteria: Patients in the acute phase of NA (characterized by severe pain and inflammation of the brachial plexus) (Prior) NA attacks of the lumbosacral plexus or the left upper extremity Sever comorbidity Any (bio)mechanical constraints of the shoulder girdle Any other central nervous system, neurological, or neuromuscular disorder

Ijspeert J, Janssen RM, Murgia A, Pisters MF, Cup EH, Groothuis JT, van Alfen N. Efficacy of a combined physical and occupational therapy intervention in patients with subacute neuralgic amyotrophy: a pilot study. NeuroRehabilitation. 2013;33(4):657-65. doi: 10.3233/NRE-130993.

Lustenhouwer R, van Alfen N, Cameron IGM, Toni I, Geurts ACH, Helmich RC, van Engelen BGM, Groothuis JT. 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. Trials. 2019 Aug 7;20(1):482. doi: 10.1186/s13063-019-3556-4.