Acute Intermittent Porphyria Associated With Transverse Myelitis In A Young Patient : A Case Report

We report the case of a 30-year-old man with a progressive descending symmetric paresis, myalgia, and action tremor, initially investigated as Guillain-Barré syndrome. The absence of alterations in the initial tests and clinical worsening prompted treatment with intravenous immunoglobulin, followed by methylprednisolone and plasmapheresis, without satisfactory response. Neuroimaging suggested transverse myelitis, and the persistence of symptoms led to a metabolic investigation, which confirmed acute intermittent porphyria. The patient was referred for rehabilitation and specialized follow-up, showing gradual improvement. This case highlights the importance of including porphyria in the differential diagnosis of transverse myelitis in patients with refractory symptoms and atypical systemic manifestations.