A 43-yr-old African American female with neurofibromatosis type 1 presented to a neurosurgeon for evaluation of a 6-mo history of worsening pain, lower limb weakness, and difficulty ambulating. Spinal magnetic resonance imaging studies showed lesions consistent with neurofibromas at multiple levels. The largest of these was noted at the T7-T9 levels in a dumbbell formation, with marked cord compression (Fig. 1).
The patient deferred surgery. Three weeks later, she returned with progressive weakness and inability to ambulate. Bowel and bladder control were retained. She underwent an urgent extradural resection of the T7-T9 mass with laminectomy and instrumentation. The mass was pathologically confirmed as a neurofibroma.
Physiatry was consulted for rehabilitation potential. Physical exam was significant for multiple cutaneous neurofibromas. No axillary freckling or café-au-lait spots were noted. Areflexia and marked weakness of the lower limbs were present, and Babinski signs were present bilaterally. Sensation was intact to pinprick throughout. Rectal tone was normal. No spasticity was noted. Examination was limited by intermittent muscle spasms. She ambulated 25 feet with a rolling walker, required moderate assistance with activities of daily living, and maximal assistance with transfers. After 11 days of inpatient rehabilitation, she functioned at a modified independent level with activities of daily living, ambulated >250 feet with a rolling walker, and required supervision for transfers. Her muscle strength had improved markedly. Spasms were controlled with dantrolene sodium, and pain was controlled with hydrocodone/acetaminophen. She was discharged home with home health physical therapy and continuation of her thoracolumbosacral orthosis. Genetic counseling was offered, but the patient deferred.
Neurofibromatosis type 1 is an autosomal dominant genetic disorder with an prevalence of 1 in 3000 live births.1 It is diagnosed by the presence of clinical features, including neurofibromas, café-au-lait spots, Lisch nodules (iris hamartomas), axillary freckling, optic gliomas, and specific bony abnormalities.2 Neurofibromas are benign, encapsulated tumors resulting from proliferation of Schwann cells and fibroblasts that include portions of nerve fibers. Spinal nerve neurofibromas causing myelopathy are uncommon, with an estimated prevalence of 2%.3 A medical literature review from 1892 to present revealed 179 cases. Myelopathy due to dumbbell neurofibromas has not been separately classified and has rarely been reported.
Myelopathy secondary to neurofibromatosis type 1 is a rare complication, but physiatrists should be aware of its possibility and the significant impairment it may cause. The role of physiatry in treating impairments due to neurofibromatosis has not been well documented, but our experience indicates that patients may benefit from the involvement of a physiatrist in their care.
1. Riccardi V: Neurofibromatosis: Phenotype, Natural History, and Pathogenesis
. Baltimore, Johns Hopkins University Press, 1992
2. Neurofibromatosis: Conference Statement. National Institutes of Health Consensus Development Conference. Arch Neurol
3. Creange A, Zeller J, Rostang-Rigattieri S: Neurological complications of neurofibromatosis type 1 in adulthood. Brain