Severe Headache and Fever in a Young Woman - Cytotoxic Lesionof the Corpus Callosum

Abstract

Introduction: Cytotoxic lesion of the corpus callosum (CLOCC) is a reversible clinic-radiologic entity associated with a wide range of infectious, metabolic, toxic, and inflammatory conditions. Recognition of its characteristic imaging appearance is essential to avoid misdiagnosis and guide appropriate management.

Case Presentation: A 19-year-old woman presented with fever and severe headache. Initial computed tomography of the brain was normal. Forty-eight hours after admission, she developed worsening fever, headache, neck stiffness, hypertension, and mild confusion. Laboratory investigations, including complete blood count, electrolytes, and renal function, were normal. Lumbar puncture demonstrated no pleocytosis, and microbiologic and viral studies were negative. Brain MRI revealed an isolated, non-enhancing lesion in the splenium of the corpus callosum with T2 hyperintensity and restricted diffusion, consistent with CLOCC.

Differential diagnoses, including meningitis, multiple sclerosis, and complex migraine, were excluded based on clinical, laboratory, and imaging findings. A follow-up MRI performed five days later demonstrated near-complete resolution of the lesion.

Discussion: CLOCC is an imaging finding with diverse etiologies, including infection, metabolic disturbances, seizures, and drug toxicity. In this patient, infectious and metabolic causes were excluded, making amitriptyline toxicity the most likely precipitating factor. The characteristic transient splenial lesion and rapid radiologic resolution supported the diagnosis. Management is directed at the underlying cause, and prognosis is generally favorable with appropriate treatment.

Conclusion: This case highlights the importance of considering CLOCC in young patients presenting with acute encephalopathic symptoms and characteristic MRI findings. Early recognition can prevent unnecessary investigations, facilitate targeted management, and avoid misdiagnosis of demyelinating or infectious disorders.