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Neurofibromatosis, Type 2: Treatment & Medication
Updated: Dec 10, 2008
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
Treatment
Medical Care
- For individuals diagnosed with neurofibromatosis type 2 (NF2), medical care consists of routine examinations focusing on some of the potential complications related to CNS or spinal cord lesions. Interval history should focus on subtle motor or sensory symptoms such as paresthesias, radiculopathies, weakness, or muscle atrophy. Unless clinical deterioration occurs, MRI of the head on an annual basis would be reasonable, as would annual eye examinations and auditory screening using BAERs.
- Annual neurologic assessment by a trained specialist is most useful in this clinical setting; the neurologist may detect subtle sensory or motor deficits even before the patient is aware of any difficulties.
- For patients with multiple medical problems associated with NF2, management by a team of specialists through a multidisciplinary clinic may provide the most comprehensive and cost-effective care over time. This is especially important with rapid advances in surgical management including such tools as stereotactic radiosurgery and auditory brainstem implants.
- For at-risk individuals who do not carry a diagnosis of NF2, such as siblings and offspring of affected persons, optimal screening recommendations are more difficult to establish. However, since early detection of tumors may improve long-term outcome, many reasons exist to consider a program of surveillance and routine screening. For families in which a specific mutation or linkage has been established, at-risk individuals may choose to know for sure whether they are at risk. Even when diagnostic certainty is not possible, but an individual's chance of having NF2 is at least 50%, annual focused examinations, accompanied by annual head MRIs and hearing evaluations with BAERs, seem to be reasonable screening options.
- Although surgical resection of symptomatic tumors represents the most common approach to clinically significant lesions, in some rare instances, radiation and/or chemotherapy may be recommended to treat disabling ependymomas. However, concerns remain regarding additional risks of radiation therapy in a patient with a germline tumor suppressor gene mutation (ie, someone with NF2) as opposed to an individual with an isolated non–NF2-related tumor.
- Therapeutic use of erlotinib has shown promise in the treatment of unresectable, progressive vestibular schwannomas, resulting in not only a decrease in tumor size but improvement in auditory function. Further clinical trials are in order before use of this oral chemotherapeutic agent can be recommended on a routine basis.4
Surgical Care
- Surgical resection of tumors remains the mainstay of treatment in NF2, with recent advances in surgery permitting preservation of hearing for some affected individuals. For small vestibular schwannomas, both surgical resection and stereotactic radiosurgery have been employed and may preserve both hearing and facial nerve function in selected patients. Larger tumors may require surgical resection despite irreversible hearing loss, especially when there is evidence of brainstem compression, facial nerve palsy or, in extreme cases, early hydrocephalus. Larger tumors may be approached surgically if a patient has a significant decline in hearing, since a debulking procedure may result in preservation of hearing or, at the minimum, prolongation of auditory decompensation.
- In recent years, auditory brainstem implants (ABIs) have been used successfully in some patients with hearing loss secondary to vestibular schwannomas. In many cases, an ABI does not restore hearing, but instead, improves the patient's ability to appreciate environmental sounds and facilitates communication.5 Prior to surgery, ABI candidates should have a frank discussion about their expectations from this procedure with a careful evaluation of their family support system.
- Unlike the vestibular lesions, intracranial meningiomas, may be quite slow growing; surgical resection should be considered only when such lesions are causing serious, disabling symptoms.
- Resection of spinal cord tumors is often quite difficult and the risks and benefits of surgery must be considered on an individual basis. To maximize operative success, acting promptly is important when neurological symptoms appear, yet complete resection of a spinal cord tumor may not always be possible and in some cases serves primarily a palliative function. Single fraction radiosurgery may also be used to treat spinal cord schwannomas, either as primary therapy or, following surgery, if residual tumor or tumor progression occurs.6
- Surgical resection of cutaneous or subcutaneous growths can be accomplished by any competent surgeon, although plastic surgical consultation is advisable for areas of great cosmetic concern, such as the face.
Consultations
- The neurologist and neurosurgeon work together closely in the management of central and spinal cord lesions in NF2. The neurologist provides valuable information regarding any changes in neurological status over time, whereas the neurosurgeon provides insight into selecting the optimal procedure and makes decisions regarding timing for surgical intervention.
- The otolaryngologist or otologist is an important consultant in the surgical management of vestibular schwannomas, especially if auditory brainstem implants are being considered. Cochlear implants, on the other hand, have not been as effective in treatment of NF2 as originally hoped and generally are reserved for a small subset of patients with vascular compromise of the cochlea without substantial nerve involvement.
- The audiologist serves as an essential member of the management team for individuals with acoustic nerve lesions. After performing annual hearing evaluations by BAER to document disease progression, he or she can provide advice regarding usefulness of amplification. For many patients, augmentation may permit good sound discrimination well into the course of the disease. The audiologist also may make suggestions regarding any additional services such as speech therapy or classes for lip reading or sign language that may be helpful as hearing deficits grow.
- The ophthalmologist is an important team member and can assist in both the diagnosis and care of the patient with NF2. Early detection of juvenile cataracts is quite helpful in making a diagnosis in an at-risk child with minimal symptomatology. Furthermore, annual follow-up for affected individuals permits early detection and possible intervention for visual loss secondary to lenticular lesions.
- Finally, the geneticist may provide both diagnostic and genetic information to affected and at-risk individuals. For family members who are considering molecular testing, an explanation of risks, benefits, and test reliability to all individuals is essential as part of the informed consent process. Issues of potential insurance discrimination, confidentiality, and privacy need to be discussed in addition to personal perspectives on undergoing such testing before an individual can provide consent. For couples considering prenatal diagnosis for NF2, genetic consultation is recommended.
Activity
Activity restriction is not necessary except as recommended by the neurologist or neurosurgeon on the basis of neurological deficits. However, patients with vestibular schwannomas need to be warned about potential balance problems, which may worsen in an underwater situation. Therefore, these individuals should be advised to never swim alone and to have someone with them at all times if they are diving or snorkeling. If disorientation occurs underwater as a result of the acoustic nerve involvement, such activities may need to be curtailed.
Medication
No effective medical therapies are known for NF2. However, in rare instances in which surgical resection of symptomatic ependymomas is not possible, chemotherapy with lomustine, vincristine, and prednisone, or carboplatin and vincristine, following radiation therapy may serve a palliative function.
More on Neurofibromatosis, Type 2 |
| Overview: Neurofibromatosis, Type 2 |
| Differential Diagnoses & Workup: Neurofibromatosis, Type 2 |
Treatment & Medication: Neurofibromatosis, Type 2 |
| Follow-up: Neurofibromatosis, Type 2 |
| Multimedia: Neurofibromatosis, Type 2 |
| References |
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References
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Further Reading
Keywords
bilateral acoustic neurofibromatosis, bilateral acoustic neuroma, central neurofibromatosis, NF2, spinal cord tumor, spinal cord schwannoma, vestibular schwannoma, meningioma, multiple meningiomas, glioma, juvenile cataracts, neurofibromatosis type 2
Treatment & Medication: Neurofibromatosis, Type 2