Cervical intradural extramedullary cavernous malformation as a rare cause of subarachnoid hemorrhage without spinal dysfunction: illustrative case

Thoracic root-related intradural extramedullary cavernoma presenting with subarachnoid hemorrhage: illustrative case

BACKGROUND

Just 5% of all cavernomas are located in the spine. Thoracic root-related subtypes are the rarest, with a total of 14 cases reported in the literature to date. Among them, only 4 presented with subarachnoid hemorrhage (SAH).

OBSERVATIONS

A 65-year-old female presented after an ictus of headache with no neurological deficits. Computed tomography (CT) demonstrated sulcal SAH, with the remainder of the workup nondiagnostic for etiology. Three weeks later, she re-presented with acute thoracic back pain and thoracic myelopathy. CT and magnetic resonance imaging suggested dubiously a T9-10 disc herniation with spinal cord compression. Surgical decompression and resection were then planned. Intraoperative ultrasound (IUS) demonstrated an intradural extramedullary lesion, confirmed to be cavernoma. Complete resection was achieved, and the patient was discharged a few days postoperatively to inpatient rehabilitation.

LESSONS

Although spine imaging is deemed to be low yield in the evaluation of cryptogenic SAH, algorithms can be revisited even in the absence of spine-related symptoms. Surgeons can be prepared to change the initial surgical plan, especially when preoperative imaging is unclear. IUS is a powerful tool to assess the thecal sac after its exposure and to help guide this decision, as in this rare entity.

Spinal intradural extramedullary cavernoma: A case report

INTRODUCTION

Cavernomas are rare vascular lesions that can occur anywhere along the neuraxis. However, they are most commonly found in the cerebral hemispheres. Spinal cavernomas are more uncommon and intradural extramedullary cavernomas are the most uncommon as they constitute only 3 % of spinal cavernomas.

PRESENTATION

A 36-year-old female presented to our neurosurgical clinic with a history of back pain radiating to the left side of the chest with left lower extremity paresthesia and ataxia without urinary disturbance. Neurological exam showed left-sided hypoesthesia below the T9 dermatome in addition to increased patellar and Achilles reflexes on the left side. MRI showed a homogeneous intradural extramedullary mass which was hyperintense on T1 and hypointense on T2 and it was surgically resected. Pathological examination confirmed the diagnosis of intradural extramedullary cavernoma.

DISCUSSION

Intradural extramedullary cavernomas are extremely rare lesions that arise within the area located between the inner surface of the dura and the pial surface of the spinal cord. Up until 2022 only 40 cases of intradural extramedullary cavernomas were reported in the literature. MRI is the preferred imaging modality and pathology is the golden standard for diagnosis. Surgical resection showed very promising results and it is considered the golden standard for treating this condition. However, surgery should be performed urgently to give an optimal outcome.

CONCLUSION

Clinicians should consider this condition in their differential diagnoses when faced with progressive spinal root compression symptoms, sudden onset myelopathy, or progressive subarachnoid hemorrhage.