Isolated Horner's syndrome and syringomyelia

Although syringomyelia has been associated with Horner's syndrome, it is typically associated with other neurological findings such as upper limb weakness or numbness. A patient is described who had an isolated Horner's syndrome as the only manifestation of syringomyelia. A 76 year old woman was discovered to have right upper lid ptosis and right pupillary miosis. Neurological examination was unremarkable, and pharmacological testing was consistent with localisation of the lesion to a first or second order sympathetic neuron. Neuroimaging disclosed a Chiari I malformation with a syrinx extending to the C2 to C4 level. An isolated Horner's syndrome may be the presenting manifestation of syringomyelia.