Dorsal midbrain syndrome (DMS) is a supranuclear palsy of vertical gaze characterized by conjugate upgaze palsy, light-near dissociation, convergence-retraction nystagmus, lid retraction, and skew deviation. Majority of cases are due to primary midbrain lesions such as strokes or neoplasms, or due to pineal gland tumors compressing the said area. Presented here is the case of a 57-year-old male who came in with a chief complaint of diplopia and the typical signs of DMS. Cranial tomography scan revealed a parenchymal hemorrhage at the left thalamocapsuloganglionic region, a rarely reported site of a primary lesion causing DMS. In this case, the syndrome may have been a consequence of the mass effects and perilesional edema associated with the thalamocapsuloganglionic hemorrhage, or may have been due to disruption of supranuclear inputs to the dorsal mibdrain. This case provides further evidence that DMS may arise from lesions without obvious involvement of the said region. This case also highlights the importance of a thorough physical examination to elicit the findings associated with DMS, and the need to correlate these with a keen analysis of diagnostic test results.
Parinaud syndrome ; conjugate gaze spasm ; convergence insufficiency ; skew deviation