1407 - Perplexing paresis without paresthesia from a parasagittal meningioma

Case Diagnosis: Pure motor stroke secondary to meningioma compression at the pre-central gyrus sparing the somatosensory cortex leading to foot drop without sensation loss

Case Description: A 73-year-old male presented with sensorineural hearing loss, tinnitus, and impaired activities of daily living. Workup including MRI revealed right parasagittal extra-axial lesion with superior sagittal sinus compression. Surgical intervention was recommended and right craniotomy for intracranial neoplasm excision was performed. Intra-operatively, the lesion was determined to be a right parasagittal meningioma arising from the junction of the middle third of the superior sagittal sinus and falx, invasive of bone. The tumor was removed en bloc, and the falx was cauterized at its apparent origin.

Postoperatively, the patient complained of new left ankle weakness. He had intact sensation to all dermatomes in the left lower extremity, however left ankle dorsiflexion strength was 0/5. There was increased tone to left plantar flexors. Acute inpatient rehabilitation was recommended to improve balance, coordination, strength, endurance, and stamina.

Discussions: Although the patient endorsed new onset postoperative ankle weakness, the physical exam suggested this was chronic, possibly suggesting secondary gain. Differential includes L4 radiculopathy and peroneal nerve injury. However, these would both present with sensation loss. Further workup such as MRI of the lumbar spine and electrodiagnostic studies are recommended.

The incidence of meningiomas is approximately 8 per 100,000. Most clinical sequelae are due to compression of surrounding structures. Recurrence is common which emphasizes the need for long term monitoring. Surgical approaches balance the goal of full resection while minimizing complications.

Conclusions: This case illustrates a rare instance of isolated compression of the precentral gyrus secondary to meningioma. Appropriate physical exam differentiated chronic from acute dorsiflexion weakness and suggested possible secondary gain. Therefore, meningiomas call for comprehensive management strategies. Further investigation is warranted to uncover the mechanism of foot weakness in this interesting case.