A Rare Case of Plus Minus Syndrome

Plus-minus syndrome is a rare neurological disorder marked by asymmetric eyelid dysfunction, typically linked to midbrain lesions. We present a case of a 32-year-old male who developed right-sided partial ptosis and left eyelid retraction following a febrile illness. Apart from these ocular findings, his neurological examination was unremarkable. Extensive investigations, including MRI brain, CE MRI brain, MRA, cerebrospinal fluid analysis, and nerve conduction studies, revealed no abnormalities. Given the recent infection and absence of structural lesions, a post-infectious demyelinating process was suspected. The patient was treated with a brief course of oral steroids, resulting in complete symptom resolution within four days. This case highlights a unique presentation of plus-minus syndrome without radiological evidence of midbrain involvement, suggesting an inflammatory or immune-mediated mechanism. It underscores the importance of considering non-structural causes in similar cases and supports the potential benefit of early corticosteroid therapy.