Neurofibromatosis type 2: a case of ptosis

Neurofibromatosis type 2 (NF2) is a disorder usually diagnosed later in life since the features are subtle in children. The hallmark is bilateral vestibular schwannomas, which may not appear until after the second decade. Other cranial nerve schwannomas occur as well. In addition, there may be schwannomas of spinal nerve roots or peripheral nerves, as well as meningiomas, gliomas, and ependymomas. Here is described a rare case of NF2 associated with a superior rectus muscle paralysis and severe ptosis. A complex surgical procedure, which achieved satisfactory results, is also described.

A 17-year-old patient with NF2 was referred to us with diagnosis of left-eye superior rectus muscle paralysis, with a later onset of unilateral severe ptosis. Best-corrected visual acuity was 20/20 in both eyes; pupillary reflexes to light and near vision were normal, and subcapsular posterior opacity of the lens was detected. Eye motility examination confirmed a left-eye superior rectus paralysis and a severe ptosis with almost absent palpebral levator muscle function. The patient showed positive familiar history for NF (the father was affected), bilateral involvement of the acoustic nerves (schwannoma), multiple neurofibromas, and bilateral posterior subcapsular lens opacity. Magnetic resonance imaging (MRI) showed bilateral acoustic neuromas in the left temporal region close to the cavernous sinus; since neurological examination and ocular motility problems had remained stationary over time, surgical correction of ptosis and strabismus was suggested.

Palpebral ptosis has rarely been reported in NF2. In the case described, ptosis associated with rectus superior palsy was caused by expansive processes in the temporal region close to the cavernous sinus. In order to resolve ptosis and vertical diplopia, we performed a complex surgery that achieved satisfactory results.