![]() NF2 patients tend to have a more severe mutation, although there are mild mosaic cases in which only some cells carry the mutation. ![]() Bilateralism is considered to be the hallmark and main diagnostic criterion of Neurofibromatosis Type II (NF2), a genetic disorder that is heritable, progressive, difficult to manage, and has a 1 in 2 chance of being passed on to each offspring. Having bilateral VSs is a more troublesome condition. Neurofibromatosis Type 2 (NF2) įor the most part, unilateral sporadic vestibular schwannomas are readily treated successfully by modern medical techniques. Late symptoms of very large VS include headache, nausea, vomiting, sleepiness, mental confusion and eventually coma. Very large tumors are life-threatening when they press on the cerebellum or cause brainstem compression. Advanced hearing loss and spells of true vertigo may occur. As 'space-occupying-lesions,' the tumors can reach 3 to 4 cm or more in size and infringe on the facial nerve (facial expression) and trigeminal nerve (facial sensation). IAC tumors that grow beyond 1.5 cm in diameter expand into the relatively empty space of the cerebellopontine angle, taking on the characteristic 'ice-cream-cone' appearance seen on MRIs. In general, although studies differ, VSs that grow are slow-growing at an average rate of 1.2 to 1.9 mm per year. Tumor growth rates are highly variable: some small VSs (perhaps 50%) do not grow at all some few grow for a time and then shrink some appear dormant but suddenly grow rapidly. There have been cases of tumors that were actually asymptomatic until very large and at a critical stage. ![]() The brain's vestibular system usually compensates for early balance problems. A sudden hearing loss, which is uncommon, might be misdiagnosed as Ménière's disease, an abnormality of the inner ear that also has tinnitus as a symptom. Initial hearing loss is usually subtle and may be attributed mistakenly to aging, earwax buildup, or perhaps exposure to some loud environmental noise. Delayed diagnosis and misdiagnosis are not unusual. Headache as a presenting symptom of VS specifically is rare facial symptoms (facial numbness, weakness) usually occur only as the tumor grows out of the canal and/or after therapeutic treatment. Gradual single-sided hearing loss in the high frequencies is the first most obvious symptom for the great majority of patients. The most common early symptoms of these intracanalicular (IAC) VSs are gradual hearing loss and a feeling of fullness in the affected ear, some imbalance or dizziness, and tinnitus (ringing or other noise in the ear). Sporadic VSs originate within the confining bony walls of the small (ca. The only environmental exposure that has been definitely associated with the growth of a VS is therapeutic radiation exposure to the head. Variations in the mutation determine the nature of the tumor's development. Although non-cancerous, they can do harm or even become life-threatening if they grow to press on other cranial nerves and vital structures such as the brainstem. They are called "sporadic" (i.e., by-chance, non-hereditary). The great majority of these VSs (95%) are unilateral, in one ear only. The tumor originates mostly on the vestibular division of the nerve rather than the cochlear division, but hearing as well as balance will be affected as the tumor enlarges. However, sometimes a mutation in the tumor suppressor gene, NF2, located on chromosome 22, results in abnormal production of the cell protein named Merlin, and Schwann cells multiply to form a tumor. Normally, Schwann cells function beneficially to protect the nerves which transmit balance and sound information to the brain. The tumor originates when Schwann cells that form the insulating myelin sheath on the nerve malfunction. Variable, based on size of tumor larger brain tumors may result in brainstem compression, headache, vomiting, vertigo, fatigue, mental disorientation, coma, and death results in less acute circumstances by advanced specialists in the field have reduced mortality rates to near 1% Ī vestibular schwannoma ( VS), also called acoustic neuroma, is a benign tumor that develops on the vestibulocochlear nerve that passes from the inner ear to the brain. Sporadic vestibular schwannoma (VS) Neurofibromatosis type II (NF2) Gradual hearing loss, dizziness, tinnitusīrain tumor growth unilateral facial paralysis, single-sided hearing loss Acoustic neuroma, acoustic neurilemmoma, perineural fibroblastoma, neurinoma of the acoustic nerve, neurofibroma of the acoustic nerve, schwannoma of the acoustic nerve īilateral schwannomas in a patient with neurofibromatosis 2
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