Diabetes Mellitus Presenting as One and Half Syndrome

Internuclearophthalmoplegia (INO) is a disorder of conjugate lateral gaze in which the affected eye shows impairment of adduction. When an attempt is made to gaze contralaterally the affected eye adducts minimally, if at all. The contralateral eye abducts however with nystagmus. Additionally the divergence of eyes leads to horizontal diplopia.51 year old male patient presented with diplopia, giddiness and vertigo with no significant past history. Ocular examination revealed loss of extraocular movements on left side and convergence nystagmus of right eye. HbA1c values suggestive of newly detected Diabetes mellitus. MRI and MRA was within normal limits. Patient was started on with oral hypoglycemic agents and steroids of 1mglkglday in divided doses. His symptoms started improving in a week. Diabetes Mellitus can be presented rarely with ONE AND HALF SYNDROME being the first presentation. Diabetic third nerve palsies may be caused by ischemia in midbrain or along peripheral nerve sparing the autonomic fibres. Thus it will be pupillary sparing ophthalmoplegia.