Seizure After Sudden Headache in a 16-Year-Old Cyclist

Payman Vahedi, MD; Zahra Mohajernezhad, MD; Mohammad Faraji-Rad, MD


March 25, 2022

Surgical intervention is indicated after considering certain factors, such as the patient's age, symptoms, and cyst size. Because of the threat of sudden death, surgery is recommended for cysts exceeding 1.5 cm in diameter in young patients, even in asymptomatic cases.[8] Symptomatic patients should always receive treatment.[9] Options for treatment include endoscopic removal of the cyst[10] and open surgery with different approaches, such as transcortical or interhemispheric transcallosal approaches.[4,9]

A study by Denby et al concluded that patients who have removal of a colloid cyst frequently experience atrophy of the mammillary bodies, and attribute this partially to a loss of temporal lobe projections in the fornix. The authors suggest that mammillary body atrophy is correlated with day-to-day memory loss experienced by patients following treatment for a colloid cyst. Denby et al used stereologic volume-estimation techniques to measure the atrophy of the mammillary bodies in 38 patients after surgical removal of colloid cysts and 20 control subjects.[11]

In this case, MRI revealed a round mass with high signal intensity on T1-weighted imaging, low signal intensity on T2-weighted imaging, and high signal intensity on FLAIR images. The patient was taken to the operating room. Bilateral external ventricular drainage was inserted in the frontal horns of the lateral ventricles. Bilateral drainage was performed because unilateral ventricular drainage may fail to reduce intracranial pressure when a third ventricular mass simultaneously obstructs both foramina of Monro. Unilateral drainage may also result in selective enlargement (or "trapping") of the contralateral lateral ventricle.

The tumor was totally resected via an interhemispheric transcallosal approach under a surgical microscope. The macroscopic appearance of the tumor was a creamy soft cyst suggestive of colloid cyst. Histopathology revealed a fibrous wall lined by inner ciliated columnar epithelium and colloid and cell ghosts, confirming the diagnosis. On the first postoperative day, the patient's diplopia and headache resolved. The patient had an uneventful postoperative course and was discharged from the hospital 6 days after surgery. She was on phenobarbital for 6 months, which was tapered and discontinued after a normal EEG. Gradual improvement in visual acuity was observed, and she regained her full vision 5 months later.


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