Objective:

Describe a rare cause of basilar leptomeningitis, racemose neurocysticercosis.

Background:

Basilar leptomeningitis has a broad differential diagnosis that includes infectious, inflammatory and neoplastic etiologies. Precision diagnosis can be facilitated by metagenomic next-generation sequencing (mNGS).

Design/Methods:

Case report

Results:

A 50-year-old Central American female with hypertension and diabetes repeatedly presented to emergency departments with worsening headache, blurry vision, vertigo and decreased hearing over the course of a year. Initially followed by otolaryngology for sensorineural hearing loss, she developed worsening exertional blurry vision. This prompted an ophthalmology referral, which revealed bilateral papilledema. Positive exam findings were expanded left eye blind spot, left face numbness in V2 distribution and right sided hearing loss. Brain magnetic resonance imaging demonstrated hydrocephalus and extensive leptomeningeal enhancement in basal cisterns, cerebellopontine angles and pial enhancement overlaying the brainstem, left cranial nerve (CN) 5, bilateral CN6 and extending into the left internal acoustic canal. Lumbar puncture (LP) revealed elevated opening pressure, lymphocytic pleocytosis with elevated eosinophils (8%) and markedly elevated immunoglobulin G index. Diagnostics for tuberculosis were repeatedly negative. A repeat LP with mNGS was positive for Taenia spp; confirming diagnosis of basilar leptomeningitis secondary to racemose neurocysticercosis (NCC). The elevated intracranial pressure was initially treated with acetazolamide, but switched to citrate acid-sodium citrate due to metabolic acidosis. Treatment initiation of racemose NCC included dexamethasone, albendazole, and praziquantel. Intracranial shunt was deferred due to high obstruction risk. Patient reported marked improvement in her symptoms within days to weeks of treatment initiation.

Conclusions:

This case describes an atypical cause of basilar leptomeningitis and a less common form of NCC, racemose NCC. The insidious and initially generic presentation posed a diagnostic challenge, and mNGS was crucial in establishing the diagnosis and appropriate treatment plan. mNGS can be considered for precision diagnosis and to ameliorate delays in diagnosis.