Abstract

Neurofibromatosis type one (NF1) is associated with a number of neurological complications including aqueduct stenosis, CNS tumours and spinal root neurofibromas. We report a case with two common complications resulting in one rare association. A 30-year-old man with NF1, epilepsy and severe anxiety presented with 2-year history of progressive gait dysfunction and mild urinary urgency. He reported no incoordination, auditory or olfactory disturbance. There was no history of trauma, thunderclap headache or neurosurgical intervention. Examination revealed a left enophthalmos and an asymmetrical spastic paraparesis. Spinothalamic sensation was impaired in the lower limbs but without a demonstrable sensory level. He had a thoracic kyphoscoliosis and typical cutaneous stigmata of NF1. Spinal cord imaging was expected to reveal cord compression but, despite a marked kyphoscoliosis and gross dural ectasia with lateral meningocele formation, only minor anterior cord indentation was seen at the T5/6 gibbus. An MR scan of the brain revealed left sphenoid wing hypoplasia and superficial siderosis of the cerebellum, brainstem and cervical cord. MR angiogram of the brain vessels failed to demonstrate any vascular abnormality to act as a source of bleeding. His anxiety (precipitated by undergoing hospital investigations) has prevented any subsequent investigation or treatment. This is the first reported case of superficial siderosis in a patient with NF1 plus both sphenoid wing hypoplasia and dural ectasia. We propose that distorted meninges at either site are the source for chronic bleeding.