SHM Converge Scientific Abstract ePoster Gallery-Beneath the Surface: Racemose Neurocysticercosis Presenting as Subarachnoid Hemorrhage Mimic

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This case describes racemose neurocysticercosis (NCC), a rare and dangerous form of the most common parasitic infection of the central nervous system worldwide. Unlike typical NCC, the racemose variant involves cyst proliferation in the subarachnoid spaces and often lacks the classic ring-enhancing lesions or visible scolex on imaging.<br /><br />A 30-year-old man from rural Guatemala presented with 5 days of worsening headache, posterior neck pain, and photophobia. He was afebrile, hemodynamically stable, and had a normal neurological exam except for meningeal signs. Laboratory studies were unremarkable, including no eosinophilia, which does not exclude NCC.<br /><br />Initial MRI showed diffuse sulcal FLAIR hyperintensity and SWI hypointensity, raising concern for subarachnoid hemorrhage (SAH). However, CTA of the head and neck was negative for aneurysm, AVM, or vasculitis. A repeat MRI 48 hours later showed resolution of the hemorrhage-like signal changes and revealed multiple CSF-isointense subarachnoid cysts in the interhemispheric fissure, Sylvian fissures, and prepontine cistern, with mild communicating hydrocephalus. One cyst showed an eccentric scolex, a pathognomonic finding (“hole with dot” sign). CSF testing was positive for Taenia solium PCR and cysticercus antigen, confirming racemose NCC.<br /><br />Management emphasized a critical safety rule: corticosteroids should be started first, and antihelminthic therapy should not begin without steroid coverage because inflammatory cyst degeneration can worsen symptoms and imaging findings. The patient received dexamethasone, followed by prolonged antiparasitic therapy with albendazole and praziquantel, along with gradual steroid tapering.<br /><br />Key teaching points are that racemose NCC can mimic SAH, transient imaging abnormalities may reflect inflammation rather than true hemorrhage, eosinophilia may be absent, and diagnosis requires integrating epidemiologic risk, evolving imaging, and confirmatory CSF testing. Multidisciplinary management is essential.

Asset Subtitle

Peter J. Mattingly

Meta Tag

Author List James Thomas, Peter J. Mattingly, Sumanth Khadke, Tirth Patel

Category Clinical Vignettes

Concept Racemose Neurocysticercosis

Concept Subarachnoid Hemorrhage Mimic

Concept Subarachnoid Cyst

Concept Corticosteroid

Concept Sulcal FLAIR Hyperintensity

Distinguished Finalist

Presenter Organization Lahey Hospital and Medical Center

Presenting Author Peter J. Mattingly

Track Adult

Keywords

racemose neurocysticercosis

Taenia solium

subarachnoid cysts

subarachnoid hemorrhage mimic

cysticercus antigen

PCR confirmation

scolex

communicating hydrocephalus

dexamethasone

albendazole praziquantel

Racemose Neurocysticercosis

Subarachnoid Hemorrhage Mimic

Subarachnoid Cyst

Corticosteroid

Sulcal FLAIR Hyperintensity