Oculomotor Nerve Palsy as a Rare Presentation and First Sign of Multiple Myeloma

Acquired oculomotor nerve palsy has varied aetiologies like vascular (diabetes, heart disease, atherosclerosis and posterior communicating artery aneurysm), space occupying lesions or tumours, inflammation, infection, trauma, demyelinating disease like Multiple sclerosis, autoimmune disorders such as Myasthenia gravis, postoperatively as a complication of neurosurgery, cavernous sinus thrombosis etc. Cranial Nerve palsies as one of the first symptoms of multiple myeloma have been reported sparsely in literature. We report a case of a 60-year-old woman who developed sudden onset right-sided pupil sparing oculomotor nerve palsy along with a tender swelling at right sternoclavicular joint. Cranial and orbital magnetic resonance imaging and cerebrospinal fluid examination demonstrated no abnormalities. Immunological investigations and histopathological analysis of sternoclavicular joint swelling confirmed the diagnosis of IgG type multiple myeloma. After confirmation of diagnosis we started her with appropriate chemotherapy, after which the palsy resolved within one month. The cause of the palsy was probably due to nerve ischemia due to hyper viscosity of the serum.