Idiopathic Intracranial Hypertension in a Child with Marfan Syndrome: Clinical, Neuroimaging, and Biomarker Findings from a Case Report

Marfan syndrome (MFS) is a connective tissue disorder classically associated with cardiovascular, musculoskeletal, and ocular manifestations. Neurological involvement is increasingly recognized and is most commonly related to spontaneous intracranial hypotension secondary to dural ectasia and cerebrospinal fluid (CSF) leakage. By contrast, idiopathic intracranial hypertension (IIH) is exceptionally rare in pediatric patients with MFS. We report the case of an 8-year-old girl with Marfan syndrome presenting with neck pain, diplopia, bilateral papilledema, and bilateral sixth cranial nerve palsy. Brain MRI demonstrated optic nerve tortuosity, distension of the perioptic subarachnoid spaces, and partial empty sella, while venous sinus thrombosis and spinal CSF leakage were excluded. Lumbar puncture confirmed markedly elevated CSF opening pressure (48 cmH2O), consistent with IIH. CSF and plasma neurofilament light chain levels were elevated, whereas anti-MOG antibodies and autoimmune investigations were negative. The patient showed rapid clinical improvement following therapeutic CSF drainage and acetazolamide treatment. To the best of our knowledge, this represents only the second report of pediatric IIH associated with Marfan syndrome. Our patient developed idiopathic intracranial hypertension, an uncommon neurological manifestation in this condition. Through this case, we aim to highlight the diagnostic challenges, discuss the possible pathophysiological mechanisms underlying this rare association and emphasize the importance of considering intracranial hypertension in the differential diagnosis of children with Marfan syndrome presenting with neuro-ophthalmological symptoms.