Small tumors (e.g., < 2.0 cm) usually are incidental findings at autopsy without having caused symptoms. Larger tumors may cause symptoms, depending on the size and location.

- Focal seizures may be caused by meningiomas that overlie the cerebrum.

- Progressive spastic weakness in legs and incontinence may be caused by tumors that overlie the parasagittal frontoparietal region.

- Tumors of the Sylvian aqueduct may cause myriad motor, sensory, aphasic, and seizure symptoms, depending on the location.

- Increased intracranial pressure eventually occurs, but is less frequent than in gliomas.

- Diplopia (Double vision) or uneven pupil size may be symptoms if related pressure causes a third and/or sixth nerve palsy.

Patients who have malignant gliomas of the optic nerve have rapidly progressive, painful visual loss accompanied by signs of an optic neuropathy. Initial visual loss may be unilateral or bilateral (chiasmal involvement), but rapid progression to bilateral blindness and death are constant features. Depending on the initial location of the tumor, visual loss may be accompanied by exophthalmos, extraocular motility

Optic nerve melanocytoma does not usually produce symptoms or grow. If they slowly grow, optic nerve melanocytoma can produce afferent pupillary defects (30%), subretinal fluid (10%), and an enlarged blind spot (75%).

On fundoscopic exam, the optic disc may be swollen, atrophic, or even normal. Central retinal vein occlusion may occur.

If the tumor is next to the optic nerve, growth can compress the nerve and cause gradual loss of vision and unilateral proptosis. Dyschromatopsia may occur. Growth can also cause compressive vascular problems like central retinal vein occlusion. Lastly, growth also causes the tumor to exceed its blood supply. In these cases, necrotic areas form inside the tumor. Necrosis can (in turn) cause intraocular and rarely orbital inflammation.

Most optic nerve tumors (65 percent) are gliomas that occur somewhere along the anterior visual pathway.

The most common symptom of ONSM is a gradual loss of vision in one eye. In a minority of patients this may be intermittent, at least to begin with. Less common symptoms include pain in the affected eye, protrusion of the eye, or double vision.

Optic nerve glioma (or optic glioma), a form of glioma which affects the optic nerve, is often one of the central nervous system manifestations of Neurofibromatosis 1.

Optic gliomas are usually pilocytic tumors, and can involve the optic nerve or optic chiasm. Optic gliomas are usually associated with neurofibromatosis type 1 in 30% of patients.

Tumors within the nerve canaliculi initially present with unilateral sensorineural hearing loss, unilateral tinnitus, or disequilibrium (vertigo is rare, on account of the slow growth of neuromas). Speech discrimination out of proportion to hearing loss, difficulty talking on the telephone are frequent accompaniments. Tumors extending into the CPA will likely present with disequilibrium or ataxia depending on the amount of extension on the brainstem. With brainstem extension, midfacial and corneal hypesthesia, hydrocephalus, and other cranial neuropathies become more prevalent.

For example, involvement of CN V from a cerebellopontine mass lesion often results in loss of the ipsilateral (same side of the body) corneal reflex (involuntary blink).

Patients with larger tumours can develop Bruns nystagmus ('dancing eyes') due to compression of the flocculi.

Meningioma, also known as meningeal tumor, is typically a slow-growing tumor that forms from the meninges, the membranous layers surrounding the brain and spinal cord. Symptoms depend on the location and occur as a result of the tumor pressing on nearby tissue. Many cases never produce symptoms. Occasionally seizures, dementia, trouble talking, vision problems, one sided weakness, or loss of bladder control may occur.

Risk factors include exposure to ionizing radiation such as during radiation therapy, a family history of the condition, and neurofibromatosis type 2. As of 2014 they do not appear to be related to cell phone use. They appear to be able to form from a number of different types of cells including arachnoid cells. Diagnosis is typically by medical imaging.

If there are no symptoms, periodic observation may be all that is required. Most cases that result in symptoms can be cured by surgery. Following complete removal less than 20% recur. If surgery is not possible or all the tumor cannot be removed radiosurgery may be helpful. Chemotherapy has not been found to be useful. A small percentage grow rapidly and are associated with worse outcomes.

About one per thousand people in the United States are currently affected. Onset is usually in adults. In this group they represent about 30% of brain tumors. Women are affected about twice as often as men. Meningiomas were reported as early as 1614 by Felix Plater.

Optic nerve sheath meningiomas (ONSM) are rare benign tumors of the optic nerve. 60–70% of cases occur in middle age females, and is more common in older adults (mean age 44.7 years). It is also seen in children, but this is rare. The tumors grow from cells that surround the optic nerve, and as the tumor grows, it compresses the optic nerve. This causes loss of vision in the affected eye. Rarely, it may affect both eyes at the same time.

It is typically a slow growing tumor, and has never been reported to cause death. However, there is concern that the tumor can grow into the brain and cause other types of neurological damage. In some patients, the tumor grows so slowly that treatment is not necessary. Standard treatments are observation, surgery, radiation therapy, and combinations of the above.

The cerebellopontine angle is the anatomic space between the cerebellum and the pons filled with cerebrospinal fluid. This is a common site for the growth of acoustic neuromas or schwannomas. A distinct neurologic syndrome of deficits occurs due to the anatomic proximity of the cerebellopontine angle to specific cranial nerves. Indications include unilateral hearing loss (85%), speech impediments, disequilibrium, tremors or other loss of motor control.

Optic gliomas often have a shifting clinical course, with sporadic periods of vision loss separated by long periods of visual stability. Optic gliomas rarely spontaneously regress.

It may affect any part of the brain or even the spinal cord, optic nerve and compact white matter. Clinical manifestations are indefinite, and include headache, seizures, visual disturbances, corticospinal tract deficits, lethargy, and dementia. A case of gliomatosis cerebri presenting as rapidly progressive dementia and Parkinson's disease like symptoms has been described in an 82-year-old woman.

Chiasmal syndrome is the set of signs and symptoms that are associated with lesions of the optic chiasm, manifesting as various impairments of the sufferer's visual field according to the location of the lesion along the optic nerve. Pituitary adenomas are the most common cause; however, chiasmal syndrome may be caused by cancer, or associated with other medical conditions such as multiple sclerosis and neurofibromatosis.

Neurofibromatosis type II (also known as MISME syndrome - multiple inherited schwannomas, meningiomas, and ependymomas) is a genetic condition which may be inherited or may arise spontaneously. The main manifestation of the condition is the development of symmetric, benign brain tumors in the region of the cranial nerve VIII, which is the "auditory-vestibular nerve" that transmits sensory information from the inner ear to the brain. Many people with this condition also experience visual problems. NF II is caused by mutations of the "Merlin" gene, which seems to influence the form and movement of cells. The principal treatments consist of neurosurgical removal of the tumors and surgical treatment of the eye lesions. Historically the underlying disorder has not had any therapy due to the cell function caused by the genetic mutation. However, new drug research and some clinical trials have shown some promise in having beneficial effects. Collaborative research to find better treatments is ongoing, such as the work of the Synodos NF-2 Consortium of scientists.

Gliomatosis cerebri (infiltrative diffuse astrocytosis) is a rare primary brain tumor. It is commonly characterized by diffuse infiltration of the brain with neoplastic glial cells that affect various areas of the cerebral lobes. These malignancies consist of infiltrative threads that spread quickly and deeply into the surrounding brain tissue, or into multiple parts of the brain simultaneously, making them very difficult to remove with surgery or treat with radiation. Gliomatosis cerebi behaves like a malignant tumor that is very similar to Glioblastoma.

While gliomatosis cerebri can occur at any age, it is generally found in the third and fourth decades of life.

This uncommon tumor accounts for less than 2% of all ear tumors. While patients present with symptoms related to the middle ear cavity location of the tumor, the tumor may expand into the adjacent structures (external auditory canal, mastoid bone, and eustachian tube). Patients come to clinical attention with unilateral (one sided) hearing loss, usually associated with decreased auditory acuity, and particularly conductive hearing loss if the ossicular bone chain (middle ear bones) is involved. Tinnitus (ringing), otitis media, pressure or occasionally ear discharge are seen. At the time of otoscopic exam, the tympanic membrane is usually intact, with a fluid level or mass noted behind the ear drum. Even though this is a "neuroendocrine" type tumor, there is almost never evidence of neuroendocrine function clinically or by laboratory examination.

Neuroendocrine adenoma of the middle ear (NAME) is a tumor which arises from a specific anatomic site: middle ear. NAME is a benign glandular neoplasm of middle ear showing histologic and immunohistochemical neuroendocrine and mucin-secreting differentiation (biphasic or dual differentiation).

In the early stages, papilledema may be asymptomatic or present with a headache. It can progress to enlargement of the blind spot, blurring of vision, visual obscurations (inability to see in a particular part of the visual field for a period of time). Ultimately, total loss of vision can occur.

The signs of papilledema that are seen using an ophthalmoscope include:

- venous engorgement (usually the first signs)

- loss of venous pulsation

- hemorrhages over and/or adjacent to the optic disc

- blurring of optic margins

- elevation of the optic disc

- Paton's lines (radial retinal lines cascading from the optic disc)

On visual field examination, the physician may elicit an enlarged blind spot; the visual acuity may remain relatively intact until papilledema is severe or prolonged.

Ferner et al. give three sets of diagnostic criteria for NF2:

1. Bilateral vestibular schwannoma (VS) or family history of NF2 plus Unilateral VS or any two of: meningioma, glioma, neurofibroma, schwannoma, posterior subcapsular lenticular opacities

2. Unilateral VS plus any two of meningioma, glioma, neurofibroma, schwannoma, posterior subcapsular lenticular opacities

3. Two or more meningioma plus unilateral VS or any two of glioma, schwannoma and cataract.

Another set of diagnostic criteria is the following:

- Detection of bilateral acoustic neuroma by imaging-procedures

- First degree relative with NF II and the occurrence of neurofibroma, meningiomas, glioma, or Schwannoma

- First degree relative with NF II and the occurrence of juvenile posterior subcapsular cataract.

The criteria have varied over time.

Raised intracranial pressure as a result of one or more of the following:

Foroozen divides the causes of chiasmal syndromes into intrinsic and extrinsic causes. Intrinsic implies thickening of the chiasm itself and extrinsic implies compression by another structure. Other less common causes of chiasmal syndrome are metabolic, toxic, traumatic or infectious in nature.

Intrinsic etiologies include gliomas and multiple sclerosis. Gliomas of the optic chiasm are usually derived from astrocytes. These tumors are slow growing and more often found children. However, they have a worse prognosis, especially if they have extended into the hypothalamus. They are frequently associated with neurofibromatosis type 1 (NF-1). Their treatment involves the resection of the optic nerve. The supposed artifactual nature of Wilbrand's knee has implications for the degree of resection that can be obtained, namely by cutting the optic nerve immediately at the junction with the chiasm without fear of potentially resulting visual field deficits.

The vast majority of chiasmal syndromes are compressive. Ruben et al. describe several compressive etiologies, which are important to understand if they are to be successfully managed. The usual suspects are pituitary adenomas, craniopharyngiomas, and meningiomas.

Pituitary tumors are the most common cause of chiasmal syndromes. Visual field defects may be one of the first signs of non-functional pituitary tumor. These are much less frequent than functional adenomas. Systemic hormonal aberrations such as Cushing’s syndrome, galactorrhea and acromegaly usually predate the compressive signs. Pituitary tumors often encroach upon the middle chiasm from below. Pituitary apoplexy is one of the few acute chiasmal syndromes. It can lead to sudden visual loss as the hemorrhagic adenoma rapidly enlarges.

The embryonic remnants of Rathke’s pouch may undergo neoplastic change called a craniopharyngioma. These tumors may develop at any time but two age groups are most at risk. One peak occurs during the first twenty years of life and the other occurs between fifty and seventy years of age. Craniopharyngiomas generally approach the optic chiasm from behind and above. Extension of craniopharyngiomas into the third ventricle may cause hydrocephalus.

Meningiomas can develop from the arachnoid layer. Tuberculum sellae and sphenoid planum meningiomas usually compress the optic chiasm from below. If the meningioma arises from the diaphragma sellae the posterior chiasm is damaged. Medial sphenoid ridge types can push on the chiasm from the side. Olfactory groove subfrontal types can reach the chiasm from above. Meningiomas are also associated with neurofibromatosis type 1. Women are more prone to develop meningiomas.

Bitemporal hemianopsia, also known as bitemporal heteronymous hemianopsia or bitemporal hemianopia, is the medical description of a type of partial blindness where vision is missing in the outer half of both the right and left visual field. It is usually associated with lesions of the optic chiasm, the area where the optic nerves from the right and left eyes cross near the pituitary gland.

Malignant meningioma is a rare, fast-growing tumor that forms in one of the inner layers of the meninges (thin layers of tissue that cover and protect the brain and spinal cord). Malignant meningioma often spreads to other areas of the body.

The World Health Organization classification system defines both grade II and grade III meningiomas as malignant. Historically, histological subtypes have also been used in classification including:

- clear cell (WHO grade II),

- chordoid (WHO grade II),

- rhabdoid (WHO grade III), and

- papillary (WHO grade III)

Benign or low grade meningiomas (WHO grade I) include meningothelial, fibrous, transitional, psammomatous, angiomatous, microcystic, secretory, lymphoplasmacyte-rich, and metaplastic.

Optic papillitis is a specific type of optic neuritis. Inflammation of the optic nerve head is called "papillitis" or "intraocular optic neuritis"; inflammation of the orbital portion of the nerve is called "retrobulbar optic neuritis" or "orbital optic neuritis". It is often associated with substantial losses in visual fields, pain on moving the globe, and sensitivity to light pressure on the globe. It is often an early sign of multiple sclerosis.

Papillitis may have the same appearance as papilledema. However, papillitis may be unilateral, whereas papilledema is almost always bilateral. Papillitis can be differentiated from papilledema by an afferent pupillary defect (Marcus Gunn pupil), by its greater effect in decreasing visual acuity and color vision, and by the presence of a central scotoma. Papilledema that is not yet chronic will not have as dramatic an effect on vision. Because increased intracranial pressure can cause both papilledema and a sixth (abducens) nerve palsy, papilledema can be differentiated from papillitis if esotropia and loss of abduction are also present. However, esotropia may also develop secondarily in an eye that has lost vision from papillitis. Retrobulbar neuritis, an inflamed optic nerve, but with a normal-appearing nerve head, is associated with pain and the other findings of papillitis. Pseudopapilledema is a normal variant of the optic disk, in which the disk appears elevated, with indistinct margins and a normal vascular pattern. Pseudopapilledema sometimes occurs in hyperopic individuals.

Workup of the patient with papillitis includes lumbar puncture and cerebrospinal fluid analysis. B henselae infection can be detected by serology. MRI is the preferred imaging study. An abnormal MRI is associated with a worse visual outcome.

Esthesioneuroblastoma will first frequently present as a nasal mass. The most common signs and symptoms of esthesioneuroblastoma are nasal obstruction (70%) and epistaxis (50%). Less common symptoms include hyposmia (loss of smell), headache, rhinorrhea, vision loss, proptosis, facial pain, diplopia (double vision), masses in the neck and changes in mental status. Esthesioneuroblastoma occurs in the upper nasal cavity, near the optic nerves and optic chiasm. Thus, tumor growth can impinge nerve function and result in vision loss and diplopia. As the tumor metastasizes to the oral cavity, there can be tooth pain and tooth mobility.

The morning glory disc anomaly (MGDA) is a congenital deformity resulting from failure of the optic nerve to completely form in utero. The term was coined in 1970 by Kindler, noting a resemblance of the malformed optic nerve to the morning glory flower. The condition is usually unilateral.

On fundoscopic examination, there are three principal findings comprising the anomaly:

1. an enlarged, funnel-shaped excavation in optic disc

2. an annulus or ring of pigmentary changes surrounding the optic disc excavation

3. a central glial tuft overlying the optic disc