Shvannoma

Description:

It is the benign encapsulated tumor growing from elements of a schwannian cover of roots of cranial or spinal nerves.

As a rule, tumors of nerves are the benign tumors affecting the main trunk of a nerve or its branch. Though any nerves, including spinal roots and a horse tail suffer, more often tumors are located subcutaneously in the form of soft educations, sometimes red color.

Distinguish two main kinds of tumors of nerves: shvannoma and neurofibromas.

Shvannoma usually happen single and grow from a nerve cover that facilitates their removal.

Shvannoma's symptoms:

Shvannoma of an eighth cranial nerve come from predoor, but not from a cochlear root (the inaccuracy of one of names of a tumor - a shvannom of an acoustical nerve is clear from here). As the vestibular system adapts to gradual destruction of a root, the shvannoma of a predoor cochlear nerve is shown by the progressing unilateral decrease in hearing, but not dizziness or some other vestibular disturbances. Inexplicable unilateral relative deafness  is the indication to an audiometriya and or to a research of acoustical evoked potentials of a brainstem, or to MRT. The growing shvannoma of an eighth cranial nerve can squeeze a cerebellum, варолиев the bridge  and a facial nerve, causing the corresponding symptoms. With rare exception, shvannoma are good-quality, and the forecast at them is favorable.

At MRT they intensively and evenly accumulate contrast.

Shvannoma's reasons:

They are formed of schwannian cells  of nervous roots. Most often the shvannoma of an eighth cranial nerve meets. On frequency the shvannoma of a trifacial is on the second place. Shvannoma can grow from a root of any cranial  and spinal nerve, except for visual  and olfactory which myelination is provided with an oligodendrogliya, but not schwannian cells.

Shvannoma's treatment:

The main method of treatment shvanny - surgical. If the tumor is small, hearing on the party of defeat manages to be kept. At large tumors hearing on the party of defeat is lost even before operation. Nevertheless surgical intervention is shown also in this situation as it allows to prevent a further prelum of structures of a back cranial pole. Use of a gamma knife at a shvannoma of a predoor cochlear nerve is so effective, as well as surgical intervention, is followed by the same frequency of complications and is not more expensive. However long-term effects of stereotaxic beam surgery are studied not enough, in particular, the risk of the secondary tumors caused by radiation is unknown.