Abstract
We report a rare case of cervical syringomyelia caused by a Chiari malformation type I combined with Noonan syndrome in a 33-year-old woman. After experiencing dissociated hypoesthesia of the right upper and lower extremities for approximately 6 months, the patient was seen at our institution. MR imaging revealed syringomyelia associated with a Chiari type I malformation. In addition to fever and pain anesthesia in the right upper and lower extremities, she was underweight, had hypertelorism, a down-salting palpebral fissure, ptosis of the eyelids, depressed nasal root, webbing in the skin of the neck, and arterioventricular septal defect, and had been late in walking unsupported. Since a genetic condition was suspected, chromosomal analysis was carried out. A diagnosis of Noonan syndrome was made. Decompressive occipital craniectomy and C1 and C2 laminectomy were performed to treat the syringomyelia, which gradually alleviated the anesthesia. Patients with Noonan syndrome tend to have mental retardation and therefore they may not notice abnormal physical sensations. Even syringomyelia may remain undiagnosed in such patients.
