From the Guidelines
Non-vestibular schwannomatosis typically presents with chronic pain, neurological deficits, and visible or palpable lumps under the skin, rather than vestibular symptoms like vertigo and unsteadiness, which are more commonly associated with vestibular schwannomas 1. The primary symptoms of non-vestibular schwannomatosis can be severe and debilitating, occurring in various parts of the body, excluding the vestibular nerve.
- Chronic pain is a common symptom, occurring in about 70% of patients, and can be localized or radiating in areas where schwannomas develop.
- Neurological deficits may occur, including numbness, tingling, weakness, or muscle atrophy in affected areas.
- Some patients develop visible or palpable lumps under the skin where tumors grow.
- Symptoms often begin in adulthood (20s-30s) and progressively worsen over time. Treatment focuses on pain management with medications, along with surgical removal of problematic tumors and physical therapy to maintain function.
- Genetic testing can confirm diagnosis, as mutations in genes like SMARCB1 or LZTR1 are often responsible.
- Regular monitoring with MRI scans is important as these patients have an increased risk of developing malignant peripheral nerve sheath tumors, though this transformation is rare 1.
From the Research
Symptoms of Non-Vestibular Schwannomatosis
- The symptoms of non-vestibular schwannomatosis include multiple non-vestibular, non-intradermal schwannomas and chronic pain 2, 3, 4.
- Pain is a predominant presenting symptom, with affection of the spine and peripheral nerves in the majority of patients 3, 4.
- Patients with schwannomatosis have lower numbers of non-vestibular cranial schwannomas, but more peripheral and spinal nerve schwannomas 4.
- The symptoms of schwannomatosis can be similar to those of neurofibromatosis type 2, but the two conditions have distinct genetic origins and courses 3, 4.
Comparison with Neurofibromatosis Type 2
- Neurofibromatosis type 2 is characterized by bilateral vestibular schwannomas, meningiomas, ependymomas, cataracts, and epiretinal membranes 2.
- In contrast, schwannomatosis is characterized by multiple non-vestibular, non-intradermal schwannomas and chronic pain 2, 3, 4.
- The life expectancy of patients with schwannomatosis is significantly better than that of patients with neurofibromatosis type 2, with a mean age at death of 76.9 years compared to 66.2 years 4.
Treatment and Management
- Treatment for schwannomatosis is typically conservative if asymptomatic and surgical if symptomatic 3.
- The goal of treatment is symptom control with preservation of neurological function 3.
- Gabapentin and other medications may be used to manage chronic pain associated with schwannomatosis, although the evidence for their effectiveness is limited to other types of neuropathic pain 5, 6.