title: Ocular manifestations of hindbrain-related syringomyelia and outcome following craniovertebral decompression.
abstract: OBJECTIVE
  To analyse and evaluate associated ocular symptoms and signs in hindbrain-related syringomyelia and their response to treatment.
  
  
  METHODS
  From a database of 275 patients treated in a single institution for hindbrain hernia and syringomyelia, 39 patients (14%) had ocular symptoms and signs. Only 31 patients were included in this study; the remainder were excluded due to inadequate follow-up information. All patients had confirmed evidence of hindbrain-related syringomyelia with MRI scan or CT myelogram. Treatment included craniovertebral decompression or ventriculo-peritoneal shunting. The mean follow-up was 23 months.
  
  
  RESULTS
  In addition to the well-recognised sign of downbeat nystagmus, classically associated with foramen magnum abnormalities, a number of other ophthalmic features were identified. Symptoms included diplopia, oscillopsia, tunnel vision and difficulty in lateral gaze. Signs included nystagmus (downbeat, horizontal, rotatory, and combinations), strabismus, disc pallor, anisocoria, ptosis and field defect. Patients were categorised into two groups depending on whether the ocular features were manifest at first presentation (group 1, n = 14) or developed later in the course of the disease (group 2, n = 17). The delay in diagnosis from first presentation was 5 and 6 years respectively. All patients underwent surgery. Craniovertebral decompression was performed in 13 patients in group 1 and in 15 patients in group 2. Ventriculo-peritoneal shunt was inserted in 1 patient in group 1 and in 3 patients in group 2, for the associated hydrocephalus. Following surgery, 100% of patients in group 1 and 82% of patients in group 2 had complete or partial resolution of their ocular symptoms and signs.
  
  
  CONCLUSIONS
  The presence of unexplained ophthalmic features such as nystagmus or oscillopsia should alert one to the potential diagnosis of hindbrain-related syringomyelia. Delay in diagnosis is often associated with poorer outcome. Surgical treatment can offer excellent results for these patients.
authors.affiliation: Birmingham and Midlands Eye Centre, Birmingham, UK.
authors.forename: A
authors.initials: A
authors.lastname: Rowlands
authors.forename: S
authors.initials: S
authors.lastname: Sgouros
authors.forename: B
authors.initials: B
authors.lastname: Williams
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D019299:Decompression, Surgical; D005128:Eye Diseases / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009192:Myelography; D013595:Syringomyelia / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt