The tumor of the acoustic nerve is mostly a benign tumor affecting the ear nerve entering the brain stem through the internal auditory canal. The cochlear nerve participates in the inner auditory canal, which is responsible for hearing, the balance nerve (the semicircular canals), and the seventh nerve, which is the motor nerve that nourishes the muscles and movement of the face when a tumor occurs. It usually affects the vestibular nerve in the inner bony auditory canal at the bottom of the skull.
When it grows and increases in size, it puts pressure on the nerves participating in it in the canal, which leads to tinnitus in the ear and increasing hearing impairment, and rarely leads to weakness of the seventh nerve because it is the most resistant to pressure on it. When the tumor increases in size and protrudes from inside the canal into the skull, it puts pressure on the brainstem, which may lead to symptoms of pressure on the brainstem, including imbalance and weakness of the swallowing muscles.
In the event that the tumor increases in size more, it may press on the brainstem strongly, which may close the cerebral spinal fluid channels and the occurrence of obstructive hydrocephalus.
Communicative hydrocephalus may occur as a result of the tumor secretion of a protein that affects all ages. In most cases, we do not know the cause, but there are genetic causes in a few cases, and it may lead to a tumor in the auditory nerve in the right and left sides, and in the cranial nerves, the nerves of the spinal cord, and the nerves of the extremities. Tumor surgery.
This surgery is done by subjecting the patient to general anesthesia, making an incision behind the ear, opening the skull with a small hole, and removing the tumor completely or partially using a microscope. The complete removal of the tumor is a major goal, but it may lead to the loss of hearing remnants if it is present, and the most dangerous thing is the occurrence of weakness (paralysis) in the auditory nerve, which may lead to paralysis of the facial muscles, twisting of the mouth, weak eyelids, and failure to close the eye, which may cause ulcers in the eyes and loss of vision. Therefore, we prefer to treat the tumor with a Gamma Knife without surgery.
Microsurgery has generally become limited to large tumors with a tumor diameter of more than 4 cm or to cases of symptomatic brainstem compression. In these cases, we perform a partial resection of the tumor to reduce its size as much as possible and relieve pressure on the brainstem in order to reduce the possibility of complications, especially the weakness of the seventh nerve, and we treat the remnants of the tumor by radiosurgery directed by the gamma knife.
Gamma-knife targeted radiosurgery
When a tumor is detected, we measure the diameter, size and extent of the tumor. In the event that the diameter of the tumor is 4 cm or less, we give the patient the choice between surgical removal by microsurgery or killing the tumor in its bud by gamma-knife radiosurgery without anesthesia, without wounding, without bleeding, and without hospitalization for more than one day. The success rate of controlling the tumor after killing it in its cradle inside the brain reaches 92%, whether by shrinking and dissolving the tumor or converting it into a silent, dead and mummified mass.
This treatment is done by installing the stereotactic surgery device on the patient's head using local anesthesia and the patient is fully conscious. We perform color imaging of the brain and determine the external borders of the tumor and the tumor coordinates with extreme accuracy and an error rate of less than 0.25 mm. We direct the gamma knife, which is aimed at killing the tumor, without causing any damage to the tissues adjacent to the tumor. And after completing the specific and meticulously studied therapeutic doses, we remove the stereotactic device from the patient’s head and he can leave the hospital on the evening of the day of treatment and return to his usual work the next day or travel to his country if he is coming from abroad, but if the tumor is large and its diameter is more than 4 cm, Or there are symptoms of pressure on the brainstem, we recommend the patient to perform a partial tumor resection with microsurgery in order to avoid complications from the total removal of the tumor, including weakness of the seventh nerve.