Postoperative supplementary motor area syndrome: clinical evolution and prognosis in nine patients after left hemispheric tumor resection.

BACKGROUND: The postoperative supplementary motor area (SMA) syndrome may complicate unilateral surgery involving the SMA cortex and manifests as contralateral or global akinesia, mutism, or speech deficit, with complete or major recovery in weeks to months. CASE SERIES: We observed retrospectively nine patients (median age 47 years, range 27-60, five female) who underwent surgery for left premotor area tumors (six intra-axial and three extra-axial). Volumetric microsurgical resection was performed with neuro-navigational assistance (Vector Vision-BrainLab™ or SonoWand Invite™). We achieved gross or near gross total resection in all cases. The patients were followed clinically for one year, with control computed tomography scan within 24-48 hours from the operation and control magnetic resonance imaging three months and one year postoperatively. Five patients had only akinesia of the contralateral limbs, two had akinesia and mutism, and the remaining two had mutism only. All recovered within three months. The severity and duration were related to the location of resection rather than the volume removed. Cortical excision closer to the premotor area was related to more prominent SMA syndrome, while the cingular gyrus' involvement related to mutism.
CONCLUSION: Prevention of SMA syndrome is not always possible in resective surgery. Given its favorable prognosis, it should be well known to the health professionals of different specialties engaged in such patients' postoperative care. The possibility of SMA should be preoperatively discussed with the patients and caregivers. HIPPOKRATIA 2020, 24(1): 38-42. Copyright 2020, Hippokratio General Hospital of Thessaloniki.