This study reports two cases of Global Rostral Midbrain Syndrome (GRMS) and corpus callosum infarction in the context of shunt overdrainage caused by obstructive hydrocephalus due to aqueductal stenosis. We detail how thorough clinical evaluation and appropriate investigation helped avoid a coma misdiagnosis and describe the excellent response to pharmacological treatment and successful neurorehabilitation in both cases. We analyze the cognitive profile of patients with GRMS, a rare condition that mimics disorders such as coma and progressive supranuclear palsy at various stages. In conscious cases, GRMS typically presents with parkinsonian syndrome, Parinaud syndrome, and cognitive issues. The awareness of this rare complication of shunt overdrainage facilitates more accurate diagnosis and better management.