Aaron Wilson, MD
Resident Physician
Stony Brook Medicine
Commack, New York, United States
A 43-year-old male with a past medical history of recurrent grade 4 astrocytoma presented to the hospital with new onset left upper extremity weakness. MRI revealed an enhancing signal abnormality along the right frontal convexity superior to a previous resection site. The patient underwent a right frontal craniotomy, during which the supplementary motor area was identified. Intraoperative motor evoked potentials (MEP) remained stable. However, post-operatively the patient exhibited flaccid paralysis in the left upper extremity and antigravity strength in the left lower extremity. Sensation remained intact. This constellation of symptoms led to a diagnosis of supplementary motor area syndrome (SMAS). Patient was transferred to acute inpatient rehabilitation for muscle strengthening and recovery. Within 2 weeks of intensive therapy, the patient was able to ambulate more than 250 feet independently and move his left upper extremity against gravity.
Discussions:
The supplementary motor area, situated anterior to the primary motor cortex, is susceptible to damage during tumor excision, resulting in SMAS. This syndrome may manifest as contralateral motor weakness, apraxia, akinesia, or impaired volitional movements. While the supplementary motor area's involvement in various gliomas is documented, predicting symptomatic patients post-surgery remains challenging. Studies indicate that despite stable MEP intraoperatively, more than two-thirds of patients experience early post-operative motor deficits. This underscores the inadequacy of MEP alone in predicting post-operative motor function. Early initiation of rehabilitation upon symptom presentation is crucial since complete resolution of motor symptoms commonly occurs within weeks.
Conclusions:
Physical and occupational therapy are vital for SMAS management, focusing on muscle strengthening, coordination, gait training, and functional rehabilitation to restore mobility and independence. Range of motion exercises and neuromuscular re-education helps prevent contractures and improve motor control. Intensive therapy optimizes recovery outcomes and improves quality of life for individuals with SMAS.
