Supplementary Motor Area Syndrome After Resection of a Dominant Hemisphere Parasagittal Meningioma: A Case Report.

Background and importance: Supplementary motor area (SMA) syndrome is a common, transient postoperative complication of intra-axial tumor resections involving the SMA and posterior cingulate gyrus. It is also reported as a rare complication of resecting extra-axial lesions. Meningiomas represent the most common, nonmalignant primary central nervous system tumor in adults, which present most commonly in parasagittal locations. Resection of dominant hemisphere parasagittal meningiomas overlying or infiltrating into the SMA region carry a recognizable risk for developing SMA syndrome postoperatively.

Clinical presentation: We present a 58-year-old woman with intermittent headaches and concern for new-onset seizures. MRI demonstrated an extra-axial mass involving the left frontal convexity and SMA region with homogenous postcontrast enhancement. There was radiographic involvement of the superior sagittal sinus and inner table of the skull. Fluid-attenuated recovery signal and perilesional vasogenic edema were also noted. The imaging findings favored a parasagittal meningioma, and surgical resection was performed. Arachnoid invasion and pial infiltration of the tumor over the SMA were evident during the operation.

Conclusion: A detailed understanding of the functional neuroanatomy and clinical pathophysiology of eloquent cortical regions is important for preoperative planning and patient counseling. Surgical resection of lesions in such areas can result in rare complications uniquely implicated in specific patient subsets. Recognizing these patients in the preoperative setting is imperative for proper counseling of patients and families.