A 67 y.o. physician comes to the ED for diplopia. She had been seen at an urgent care and had a CT of the head
The patient is totally neuro intact except for a L 6th nerve palsy. What do you see?
there appears to be edema around a mass
the mass is larger as you approach the chiasm. What is it?
Our patient had a planum meningioma. These are very slow growing tumors arising from the roof of the sphenoid sinus between the optic nerves and the anterior clinoid process. Meningiomas represent 37% of primary brain tumors with planum meningioms representing 5-10% of meningiomas. They are usually reported after age 65 because they are so slow growing. The symptoms are usually visiual because of compression of the optic nerves but if they are located more anteriorly in the olfactory groove anosmia can be the presenting symptom.
MRI is the confimatory test where the lesion appears isointense on T1 images . Often there is heterogeneous enhancement secondary to calcification in which the MRI is said to resemble a flower, the evening primrose.
the planum meningioma is said to resemble a primrose with calcification appearing as petals.
While the planum meningioma can grow to a large size because it is in a silent area of the brain; other areas are silent as well.
SILENT AREAS OF THE BRAIN
The cerebellum- is called the silent area of the brain because electrical excitation of the cerebellum does not cause any conscious sensation and rarely causes motor movement. It is extremely important in muscle control, balance and movement, yet people born without one lead normal lives.
The prefrontal cortex- was the last area of the mammalian brain to develop and for many years little was known about its function. It has more recently been associated with executive function: tact, tenacity and working memory all require prefrontal cortex function. These functions make it difficult to clinically test for a tumor in this area. Most often it is described by family as a “personality change”. A classic example of frontal lobe malfunction is the case of Phineas Gage, who had an iron rod blasted through his head.
Gage had a personality changes and could no longer follow through with a plan . He worked in California during the gold rush.
The temporal lobes-to detect abnormalities of the temporal lobes look for abnormal functions of the hippocampus(memory) and amygdala (emotion). Kluver-Bucy syndrome is the result of tumor or damage to the temporal lobes and results in inappropriate sexual behavior.
while Kluver Bucy syndrome is most often associated with temporal lobe injury causing hypersexuality; in the original experiments monkeys also lost their fear responses as in this monkey looking at a cobra.
With advances in imaging, tumors in “silent” areas of the brain can be identified. These same advances in imaging lead to findings of incidental “strokes” in one in four people that are asymptomatic.
Our patient underwent a resection of her meningioma and was discharged home.
Rath S, Varma D, Tibrewal S, Ganesh S, Gupta N. A flower in the brain: planum meningioma. Indian J Ophthalmol. 2020 Nov 68(11):2514-2516.
Lutwak N, Dill C, Wieczorek R. Planum sphenoidale meningioma leading to visual disturbance. BMJ Case Reports. 2011 doi: 10.1136/bcr. 07.2011.4511.
Leung L, Weinstein G. Clinicians’ perspectives on incidentally discovered silent brain infarcts-a qualitative study. PloS One 2018;13(3) e0194971 doi:10.1371/journal pone.0194971.