Atypical isolated nuclear oculomotor nerve syndrome: a diagnostic challenge.

To cite: Liao B, KamiyaMatsuoka C. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2014207749 DESCRIPTION A 44-year-old man with hyperlipidaemia and chronic hepatitis C infection presented with a 48 h history of diplopia and occipital headaches. On neurological examination, he was alert and afebrile. There was right oculomotor palsy consisting of right medial rectus, inferior rectus and inferior oblique weakness; without ptosis or superior rectus weakness and with intact pupillary and consensual reflexes; otherwise the rest of the examination was unremarkable. CT of the head and neck showed normal extracranial and intracranial vessels. Transthoracic echocardiogram was essentially a normal study. MRI of the brain showed a non-enhancing lesion and restricted diffusion-weighted imaging without apparent diffusion coefficient map correlation in the right periaqueductal white matter, suggesting a subacute stroke (figure 1). No enhancement, vasogenic oedema or other lesions to suggest demyelinating disease or underlying tumour were present. The patient presented with isolated nuclear oculomotor nerve palsy. It usually consists of complete ipsilateral third nerve palsy in addition to contralateral ptosis and superior rectus dysfunction, furthermore, if the nuclear lesion is rostral, it may present with pupillary involvement and muscles may be spared. Isolated nuclear oculomotor nerve syndrome has been reported in patients with mesencephalic haematomas, ischaemic strokes 3 and metastases. To the best of our knowledge, this is the first case of isolated nuclear oculomotor nerve palsy with atypical features that may mimic ischaemic oculomotor nerve palsy, usually associated with diabetes mellitus and hypertension. Learning points