Dorsal midbrain syndrome from thalamocapsuloganglionic hemorrhage: A case report

@#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.

Early Dorsal Midbrain Syndrome Mimicking an Adie's Tonic Pupil

BACKGROUND: While tonic pupils have been attributed to various diseases, including syphilis, herpes zoster, orbital trauma, temporal arteritis, endometriosis, and paraneoplastic syndromes, obstructive hydrocephalus has not been implicated. CASE REPORT: A 36-year-old woman visited a neurology department with a 7-day history of throbbing headache and blurred vision in both eyes. She had early dorsal midbrain syndrome mimicking an Adie's tonic pupil, and cholinergic supersensitivity was demonstrated using topical 0.125% pilocarpine. Brain MRI revealed obstructive hydrocephalus at the level of the aqueduct of Sylvius, and her symptoms resolved 4 days after surgery. CONCLUSIONS: We report a patient with early dorsal midbrain syndrome that was initially believed to represent a tonic pupil on the basis of pharmacologic testing. The findings in our patient suggested that early dorsal midbrain syndrome mimicking an Adie's tonic pupil can be caused by obstructive hydrocephalus compressing the Edinger-Westphal nucleus.