gms | German Medical Science

68th Annual Meeting of the German Society of Neurosurgery (DGNC)
7th Joint Meeting with the British Neurosurgical Society (SBNS)

German Society of Neurosurgery (DGNC)

14 - 17 May 2017, Magdeburg

Reversible reorganization of motor area and excitability in cervical spondylotic myelopathy: The Corticospinal Reserve

Meeting Abstract

  • Anna Zdunczyk - Charité Berlin, Klinik für Neurochirurgie, Berlin, Deutschland
  • Vera Schwarzer - Charité Universitätsmedizin, Neurochirurgische Klinik, Berlin, Deutschland
  • Ina Bährend - Charité – Universitätsmedizin Berlin, Campus Virchow Klinikum, Neurochirurgische Klinik, Berlin, Deutschland
  • Thomas Picht - Charité – Universitätsmedizin Berlin, Campus Virchow Klinikum, Neurochirurgische Klinik, Berlin, Deutschland
  • Peter Vajkoczy - Charité - Universitätsmedizin Berlin, Campus Mitte, Neurochirurgische Klinik, Berlin, Deutschland

Deutsche Gesellschaft für Neurochirurgie. Society of British Neurological Surgeons. 68. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 7. Joint Meeting mit der Society of British Neurological Surgeons (SBNS). Magdeburg, 14.-17.05.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocMi.15.04

doi: 10.3205/17dgnc465, urn:nbn:de:0183-17dgnc4656

Published: June 9, 2017

© 2017 Zdunczyk et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at



Objective: We have recently shown a compensatory reorganization of the corticospinal network in patients with cervical spondylotic myelopathy which led to the concept of the ‘corticospinal reserve capacity’. In patients with mild symptoms (JOA>12) and preserved reserve an increased motor area due to a higher recruitment of supplementary motor areas was observed. In contrast, severely symptomatic patients (JOA<12) with an exhausted reserve presented with a restricted motor area, reduced recruitment curve and increased inhibition. Here we present the 9 months follow up in order to study how the status of the reserve impacts on the outcome after decompression and whether these plastic changes are reversible

Methods: 9 patients with a cervical myelopathy due to cervical spinal canal stenosis were examined preoperatively and in a 9 months follow up with nTMS. On the basis of the initial JOA score two patient groups were established (JOA<12/>12). We determined the resting motor threshold, recruitment curve, cortical silent period and motor area for the FDI muscle bilaterally.

Results: The RMT showed no difference in the follow up measurement for both groups (preoperative/ follow up RMT JOA<12 p=.069/ JOA>12 p=.060) Operative decompression let to a reconstitution of motor area size in the severely symptomatic patient group (motor area left / right hemisphere mean ± SD preoperative JOA<12: 194,4 ± 121,3 mm2/ follow up 430,1 ± 253,4 mm2 p=.034). These patients presented with a good clinical recovery (JOA<12 group: JOA preoperative 9,0 ± 0,5/ follow up 12,4 ± 2,5). In patients with preoperatively few symptoms (JOA>12) and preserved corticospinal reserve no significant change in motor area size was detected. However the compensatory increased recruitment of supplementary motor areas and disinhibition diminished after 9 months (JOA>12 M2 area preoperative 59,4 ± 91,8 mm2 / follow up 2,1 ± 4,2 mm2 p=.023; CSP preoperative 147.5 ± 37.8 ms/ follow up 164.3 ±41.8 ms p=.03) These patients remained clinically stable during follow up (JOA preoperative 14,2 ± 1,3/ follow up 13,8 ± 1,9)

Conclusion: Based on these results, we could detect reversible adaptive mechanisms on the cortical and spinal level, i.e. corticospinal reserve capacity. This functional reorganization appears to be reversible following surgical decompression. Furthermore, operative decompression let to a reconstitution of motor area size in patients with an exhausted reserve. This was also reflected in a good clinical recovery. These changes in nTMS parameters might serve as a valuable prognostic factor in these patients in the future.