Blurred vision as presenting symptom of brain tumor Case history Patient is a 7 year old boy who describes trouble seeing the board at school. Past medical history: none Past ocular history: none Exam: Vision without glasses is 20/25 in the right eye and 20/40 in the left. Pupils, color vision and anterior segment are all normal. Dilated retinal exam: Right eye:             Left eye:       The optic nerve is crowed and the nasal disc margin appears hazy in both eyes. Fluorescein angiogram: Subtle stain. Right eye:   Left eye:     Clinical impression: Papilledema in both eyes The optic nerves are slightly abnormal in each eye.
Normal Nerve :		Patient Nerve:

The patient has good vision and few complaints (a 7 year old may not be a complainer).

A visual field was considered to assess the optic nerve function. Given the patient's age, a visual field was deferred.

Are the optic nerves a normal variant, or due to disease?

Although the vision was normal, the optic nerves appear swollen.   Our concern was that there could be increased intracranial pressure with secondary swelling of the optic nerves (papilledema).  The patient was referred for MRI of the brain and orbits.

MRI:

There is a large enhancing lesion above the fourth ventricle.  Marked hydrocephalus, with enlargement of the lateral ventricle is noted.

Diagnosis:

Probable Meduloblastoma

Meduloblastoma is the most common brain tumor in childhood.  Meduloblastomas arise in the fourth ventricle.  Most tumors are fast growing, causing symptoms such as headaches, unsteadiness, or vomiting.

Treatment consists of surgery, radiation, and chemotherapy.  Due to the location of the tumor, successful surgical removal can still be complicated by neurological problems afterwards.