01Approach to the Critical Patient/attcp53

Immediate priorities

›Life-threatening presentations requiring immediate action

›Raised intracranial pressure

›Papilledema on fundoscopy

›Cushing triad: hypertension, bradycardia, irregular respirations

›Decreased level of consciousness

›Status epilepticus

›Continuous seizure > 5 minutes

›Two or more seizures without full recovery

›Cysticercotic encephalitis

›Diffuse cerebral edema with mass effect

›Hundreds of cysts on imaging

›Typically in children or young women

›Obstructive hydrocephalus

›Acute non-communicating pattern from ventricular cyst

›Bruns syndrome: sudden loss of consciousness with head movement

Stabilization priorities

›Airway and seizure control first

›Benzodiazepines for active seizures

›Lorazepam 0.1 mg/kg IV, max 4 mg per dose

›Diazepam 0.15 mg/kg IV if lorazepam unavailable

›Load with AED after benzodiazepine

›Levetiracetam 60 mg/kg IV over 15 minutes, max 4500 mg

›Phenytoin 20 mg/kg IV at max 50 mg/min with cardiac monitoring

›Valproate 40 mg/kg IV over 10 minutes as alternative

›Do NOT initiate antiparasitic therapy acutely

›Symptom control must precede antiparasitic treatment

›IDSA/ASTMH guideline recommendation

02History/hx59

Presenting symptoms

›Core neurologic symptoms

›New-onset seizures

›Most common presentation of NCC

›Focal, focal with secondary generalization, or generalized

›Responsible for ~29% of seizures in endemic areas

›Accounts for ~2% of ED seizure visits in the United States

›Headache

›Severe or progressive character

›Positional component suggests hydrocephalus

›Altered mental status or confusion

›Degree and acuity of change

›Visual changes

›Blurred vision or floaters suggesting ocular involvement

›Visual field deficits from posterior fossa lesions

›Focal neurologic deficits

›Hemiparesis

›Cranial nerve palsies

›Gait disturbance

›Numbness or paresthesias

Exposure and travel history

›Geographic exposure

›Origin from or travel to endemic regions

›Latin America

›Sub-Saharan Africa

›South or Southeast Asia

›Latency from infection to symptoms can be months to decades

›Do not limit inquiry to recent travel

03Physical Exam/exam48

Vital signs and general

›Hemodynamic snapshot

›Blood pressure

›Hypertension with bradycardia as Cushing response to raised ICP

›SBP and DBP trend

›Heart rate

›Bradycardia in ICP crisis

›Temperature

›Significant fever suggests secondary bacterial infection or encephalitis

›Afebrile is typical for uncomplicated NCC

›Respiratory rate

›Irregular respirations in Cushing triad

Neurologic examination

›Mental status

›Level of consciousness

›GCS score

›Degree of alertness and orientation

›Confusion or encephalopathy

›Cysticercotic encephalitis pattern

›Focal deficits

›Motor strength bilateral upper and lower extremities

›Hemiparesis suggesting parenchymal or large cyst

›Todd paralysis post-ictal weakness assessment

›Cranial nerve palsies

›CN VI palsy from elevated ICP

›Other cranial nerve deficits from subarachnoid NCC

›Gait and coordination

›Ataxia from posterior fossa cyst

04Differential Diagnosis/ddx51

Life-threatening mimics

›Structural and infectious emergencies

›Brain abscess

›ICD-10 G06.0

›Fever, focal deficits, ring-enhancing lesion with restricted diffusion on DWI MRI

›Distinguishing: DWI restriction, rapid clinical deterioration, pronounced fever

›Tuberculous meningitis or tuberculoma

›ICD-10 A17.0

›Systemic TB symptoms: fever, night sweats, weight loss, adenopathy

›Ring-enhancing lesion with meningeal enhancement

›CNS lymphoma

›Periventricular enhancement pattern

›Immunocompromised host, particularly HIV/AIDS

›Obstructive hydrocephalus from any cause

›Non-NCC etiology: ependymoma, aqueductal stenosis

Parasitic and infectious mimics

›Other CNS parasites and infections

›Toxoplasmosis

›ICD-10 B58.2

›CD4 < 0.1 x 10^9/l in HIV, multiple ring-enhancing lesions

›Basal ganglia predilection

›Distinguishing: immunocompromised host, responds empirically to pyrimethamine-sulfadiazine

›Echinococcal hydatid cyst

›ICD-10 B67.99

›Usually single large non-enhancing cyst

›No scolex visible; daughter cysts visible within parent cyst

›Cerebral malaria

›Travel to malaria-endemic region

05Laboratory Tests/lt55

Serology and confirmatory testing

›Enzyme-linked immunotransfer blot (EITB)

›Preferred confirmatory serologic test

›Sensitivity approximately 98%, specificity approximately 100%

›Uses parasite glycoproteins as antigens

›Available through CDC and select reference laboratories

›Limitations

›Approximately 30% of patients with a single cyst may test negative

›Reduced sensitivity in calcified-only disease

›Avoid crude antigen ELISA

›Poor sensitivity and specificity

›Not recommended by IDSA/ASTMH guideline

›Antigen-detection ELISA

›Useful for subarachnoid NCC follow-up

›Quantitative levels correlate with disease activity

›Guide duration of antiparasitic therapy

›Less useful for parenchymal disease

Hematologic and metabolic labs

›Complete blood count

›Eosinophilia

›May be present but not reliable for diagnosis

›More common in extraparenchymal disease

›Leukocytosis

›Suggests superimposed bacterial infection or cysticercotic encephalitis

›Comprehensive metabolic panel and liver function tests

›Baseline before initiating albendazole

›Hepatotoxicity risk with albendazole therapy

›Monitor LFTs during and after treatment

06Diagnostic Tests/dt86

Scoring Systems

›Del Brutto diagnostic criteria for NCC

›Absolute criteria (pathognomonic)

›Histologic demonstration of the parasite from brain or spinal cord biopsy

›Scolex (hole-with-dot sign) on CT or MRI

›Subretinal parasite on fundoscopic examination

›Major criteria

›Cystic lesion without scolex on neuroimaging

›Enhancing lesion < 20 mm diameter on neuroimaging

›Multilobular cystic lesion in subarachnoid space

›Positive EITB serology for anti-cysticercal antibodies

›Minor criteria

›Lesions compatible with NCC without full major criteria

›Clinical manifestations compatible with NCC

›Positive CSF ELISA for anticysticercal antibodies or cysticercal antigens

›Cysticercosis outside CNS (subcutaneous, muscle)

›Epidemiologic criteria

›Evidence of household contact with Taenia solium

›Individuals coming from or living in endemic region

›History of frequent travel to endemic region

›Interpretation

›Definitive diagnosis: one absolute criterion or two major plus one minor and one epidemiologic

›Probable diagnosis: one major plus two minor and one epidemiologic

MRI

›MRI brain with and without contrast

›Gold standard imaging for NCC

›Superior to CT for scolex visualization

›Better for posterior fossa lesions

›Detects intraventricular and subarachnoid cysts not seen on CT

›Staging by MRI appearance

›Vesicular (viable) stage

›Cystic lesion with scolex inside (hole-with-dot sign)

›Minimal surrounding edema

›No contrast enhancement

›Colloidal (degenerating) stage

›Ring or nodular contrast enhancement

›Surrounding edema

›Poorly defined borders

›Granular-nodular stage

›Nodular enhancing lesion

›Shrinking cyst cavity

›Calcified stage

›Hypointense nodule on T2

›No enhancement on post-contrast sequences

›Key sequences

›FLAIR for perilesional edema and scolex identification

›3D volumetric sequences (FIESTA, 3D-CISS, BFFE) for extraparenchymal cysts

›DWI to distinguish from brain abscess (restriction not typical in NCC)

›Post-contrast T1 for enhancement pattern

›Spine MRI

›Indicated in all patients with intracranial subarachnoid disease

›Approximately 60% have concurrent spinal involvement

›Can cause radiculopathy or myelopathy

CT

›CT head non-contrast

›First-line imaging in the ED

›Rapidly available

›Best modality for detecting calcified lesions

›Punctate calcifications highly suggestive of prior NCC

›CT findings by stage

›Vesicular stage: hypodense cyst ± scolex, minimal edema

›Colloidal stage: ring enhancing lesion with edema

›Calcified stage: hyperdense punctate nodule

›CT indications over MRI in acute ED setting

›Evaluate for hydrocephalus rapidly

›Rule out hemorrhage or herniation before LP

›Patient too unstable for MRI

›CT limitations

›Inferior to MRI for posterior fossa, ventricular, and subarachnoid cysts

›Cannot reliably detect scolex in most cases

›Misses small parenchymal lesions

›CT with contrast

›Enhancing lesions in degenerating stages

›Single enhancing lesion (SEL) pattern common presentation

›Differentiating from other ring-enhancing etiologies

Ultrasound

›Point-of-care ultrasound applications

›Soft tissue sonography

›Identification of subcutaneous cysticercal cysts

›Characteristic appearance: oval cyst with echogenic scolex

›Confirms extraneural cysticercosis supporting diagnosis

›Optic nerve sheath diameter (ONSD)

›ONSD > 5 mm suggests elevated ICP

›Non-invasive surrogate for papilledema assessment

›Bedside adjunct when fundoscopic exam limited

›Ocular ultrasound

›Evaluation for intraocular cysts

›B-scan identifies subretinal or vitreous cysts

›Useful when direct visualization limited

›Helps guide ophthalmology consultation priority

07Disposition/dispo40

Admission indications

›Criteria requiring hospital admission

›Neurologic compromise

›Altered mental status or decreased level of consciousness

›Focal neurologic deficits

›Status epilepticus or recurrent seizures

›Raised intracranial pressure or hydrocephalus

›Papilledema

›Ventricular enlargement on imaging

›Requires neurosurgical evaluation

›Cysticercotic encephalitis

›Medical emergency requiring ICU-level care

›Antiparasitic therapy contraindicated until edema controlled

›Multiple viable cysts requiring antiparasitic initiation

›Monitoring for inflammatory worsening mandatory

›IDSA recommendation for inpatient observation

›Ventricular or subarachnoid NCC

›Higher morbidity; neurosurgical intervention often required

ICU indications

›ICU-level care triggers

›Status epilepticus not responding to initial therapy

›Intubation and continuous EEG monitoring

›Continuous midazolam or propofol infusion

›Severe elevated ICP with herniation risk

›Neurosurgical emergency consult

›Cysticercotic encephalitis

›Diffuse edema, mass effect, high-dose steroids required

08Treatment/t89

Seizure management

›Acute seizure control

›First-line benzodiazepine

›Lorazepam 0.1 mg/kg IV up to 4 mg per dose

›Repeat once after 5 minutes if seizure continues

›Diazepam 0.15 mg/kg IV as alternative

›Second-line AED loading

›Levetiracetam 60 mg/kg IV over 15 minutes, max 4500 mg

›Preferred: fewer drug interactions

›Effective for focal seizures in NCC

›Phenytoin 20 mg/kg IV at max 50 mg/min

›Cardiac monitoring required during infusion

›Target level 10-20 mcg/ml (40-79 mcmol/l)

›Valproate 40 mg/kg IV over 10 minutes

›Avoid in hepatic dysfunction and pregnancy

›Long-term AED therapy

›Continue for at least 2 years after last seizure in multicystic disease

›Single enhancing lesion: can consider withdrawal after lesion resolution and 3 months seizure-free

›CT before AED discontinuation to assess for residual calcifications

Antiparasitic therapy

›Albendazole

›Dose and administration

›15 mg/kg/day divided every 12 hours, maximum 800 mg/day

›Take with fatty meal to enhance absorption

›Duration 10 to 14 days

›Indications by cyst number

›1 to 2 viable parenchymal cysts: albendazole monotherapy

›Single enhancing lesion: 7 to 14 days

›FDA-approved for parenchymal NCC

›Drug interactions

›Dexamethasone increases albendazole sulfoxide levels by approximately 56%

›Praziquantel increases albendazole sulfoxide levels by approximately 50%

›Praziquantel

›Dose and administration

›50 mg/kg/day divided every 8 hours

›Duration 10 to 14 days

›Alternative or combination indications

›Alternative to albendazole in single cyst

›Combination with albendazole for > 2 viable cysts (superior to monotherapy)

›Combination therapy

›Albendazole plus praziquantel for > 2 viable cysts

›Superior to albendazole alone based on randomized controlled trial evidence

›IDSA/ASTMH guideline recommendation

›Destroys 60 to 80% of parenchymal cysts

›Contraindications to antiparasitic therapy

›Diffuse cerebral edema or cysticercotic encephalitis

›Risk of fatal cerebral herniation

›Uncontrolled hydrocephalus

›Treat hydrocephalus first, then antiparasitic

›Ocular cysticercosis not cleared by ophthalmology

›Intraocular inflammation can cause irreversible vision loss

›Calcified-only disease

›No viable cysts to treat; antiparasitics not indicated

›Subarachnoid and ventricular NCC

›Prolonged antiparasitic courses

›Often weeks to months rather than standard 10 to 14 days

›Guided by antigen levels and imaging response

›Surgery often required in addition to antiparasitics

›Endoscopic cyst removal for intraventricular cysts

›VP shunt for chronic hydrocephalus

Anti-inflammatory therapy

›Corticosteroids

›Dexamethasone

›0.1 mg/kg/day IV or PO

›Start before or concurrent with antiparasitic therapy (ideally 1 day before)

›Suppresses inflammatory response to cyst destruction

›Also increases albendazole bioavailability by 56%

›Prednisone

›1 to 2 mg/kg/day as oral alternative

›Taper over weeks for subarachnoid or encephalitis presentations

›Monitoring during corticosteroid therapy

›Blood glucose monitoring for hyperglycemia

›Gastric protection with PPI or H2 blocker

›Screen for Strongyloides before prolonged use

›Steroid-sparing agent for subarachnoid NCC

›Methotrexate

›7.5 to 20 mg orally per week

›Used when prolonged steroids cause unacceptable toxicity

›IDSA recommendation for refractory subarachnoid NCC

Surgical management

›Hydrocephalus management

›External ventricular drain (EVD) for acute obstructive hydrocephalus

›Emergent decompression

›Bridge to definitive shunt or endoscopic procedure

›Ventriculoperitoneal shunt for chronic hydrocephalus

›Often combined with antiparasitic therapy

›Shunt revision may be required if cyst obstructs catheter

›Endoscopic neurosurgery

›Endoscopic removal of intraventricular cysts

›Fourth ventricle and third ventricle cysts

›Preferred over open craniotomy when accessible

›Endoscopic third ventriculostomy

›Alternative to shunt in selected cases of obstructive hydrocephalus

09Special Populations/sp64

Pregnancy

›Pregnancy-specific considerations

›Antiparasitic safety

›Albendazole is teratogenic in animal studies

›Category C: avoid in first trimester if possible

›Defer antiparasitic therapy to second trimester when clinically safe

›Praziquantel: limited human data; use only if benefit outweighs risk

›Corticosteroid use in pregnancy

›Prednisone preferred over dexamethasone for prolonged courses

›Betamethasone if premature delivery possible (fetal lung maturity)

›Monitor for gestational diabetes during steroid use

›Seizure management in pregnancy

›Levetiracetam preferred AED in pregnancy

›Avoid valproate (neural tube defect risk)

›Phenytoin: fetal hydantoin syndrome risk, use with caution

›Imaging considerations

›MRI without gadolinium preferred over CT

›Gadolinium: avoid unless essential (crosses placenta, category C)

›CT with fetal shielding when MRI unavailable or patient unstable

›Maternal oxygenation target SpO2 >= 95%

›Fetal monitoring when viable gestation

›Obstetrics consultation for all pregnant patients with NCC

Geriatric

›Older adult specific considerations

›Atypical presentations

›Cognitive decline as primary presentation mimicking dementia

›Falls from focal weakness or seizure

›Higher prevalence of calcified incidental lesions from prior infection

10Background/b76

Epidemiology

›Global burden

›Most common parasitic infection of the CNS worldwide

›Leading cause of acquired epilepsy in endemic regions

›Responsible for approximately 29% of seizures in endemic areas

›Responsible for approximately 2% of ED seizure visits in the United States

›Geographic distribution

›Latin America, sub-Saharan Africa, parts of South and Southeast Asia

›Endemic regions defined by presence of free-range pig farming and poor sanitation

›United States burden

›Over 2,000 cases diagnosed annually

›Predominantly among immigrant populations from endemic regions

›Domestic transmission documented through contact with infected individuals

›Mortality and morbidity

›Extraparenchymal NCC carries significantly higher morbidity and mortality than parenchymal forms

›Subarachnoid NCC: high fatality rate without optimal treatment

›Parenchymal NCC with few cysts generally favorable prognosis

Pathophysiology

›Life cycle and transmission

›Causative organism

›Larval form of the cestode Taenia solium

›Humans are accidental intermediate hosts (cysticercosis)

›Humans are definitive host for intestinal tapeworm (taeniasis)

›Transmission mechanism

›Fecal-oral ingestion of T. solium eggs from contaminated food/water

›Close contact with intestinal tapeworm carrier

›Autoinfection in patient with intestinal taeniasis

›Larval migration

›Oncospheres hatch in small intestine

›Penetrate intestinal wall and enter bloodstream

›Disseminate to muscle, subcutaneous tissue, and CNS

›Cyst development in CNS

›Preferred sites

›Parenchyma: gray-white matter junction (most common)

›Ventricles: fourth ventricle most common intraventricular site

›Subarachnoid space: basilar cisterns

›Spinal cord: less common

›Cyst stages

›Vesicular: viable cyst with clear fluid and scolex; minimal host immune response

›Colloidal: host immune response causes cyst degeneration; edema and inflammation

›Granular-nodular: further degeneration; dense inflammatory infiltrate

›Calcified: end-stage; calcified nodule; may remain symptomatic (perilesional edema)

›Pathologic mechanisms of neurologic injury

›Mass effect from enlarging cysts

›Inflammatory response to degenerating cysts causing edema and seizures

›Obstructive hydrocephalus from ventricular cysts

›Vasculitis from subarachnoid inflammation causing stroke (lacunar infarctions)

›Arachnoiditis from chronic subarachnoid disease

Therapeutic Considerations

›Antiparasitic treatment principles

›Efficacy

›Destroys 60 to 80% of parenchymal viable cysts

›Reduces seizure recurrence with active cysts

›Cochrane review supports antiparasitic treatment for parenchymal NCC

›American Academy of Neurology guideline supports treatment for active parenchymal cysts

›Treatment timing

›Symptom control must precede antiparasitic initiation

›Ophthalmologic clearance mandatory before starting

›Concurrent or prior corticosteroid cover essential

›Treatment monitoring

›LFTs and CBC during albendazole course

›MRI at 6-month intervals until cyst resolution

›Antigen-detection ELISA for subarachnoid disease activity follow-up

›Anti-inflammatory principles

›Corticosteroid rationale

›Suppresses inflammatory cascade triggered by cyst death

›Prevents fatal cerebral edema response

›Enhances albendazole bioavailability as secondary benefit

›Prolonged courses required for subarachnoid NCC

›Weeks to months depending on disease activity

›Steroid-sparing agents for toxicity management

›Surgical considerations

›Endoscopic approach preferred over open craniotomy for intraventricular cysts

›VP shunt long-term complication risk: shunt obstruction from cyst debris

›Surgery does not replace medical antiparasitic therapy in most forms

›Public health considerations

›Household contact screening and tapeworm treatment to interrupt transmission

›Prevention: cooked pork, sanitation, hand hygiene

›Reportable disease in many jurisdictions

11Patient Discharge Instructions/pdi37

copy discharge instructions

›Home care instructions for neurocysticercosis

›Take all prescribed medications exactly as directed

›Albendazole: take with a fatty meal (cheese, peanut butter, whole milk) to improve absorption

›Antiseizure medication: never skip doses

›Steroids: do not stop suddenly without physician guidance

›No driving until seizure-free period met per local regulations

›Discuss with your physician when it is safe to drive

›No swimming alone or working at heights

›Seizure precautions until cleared

›Avoid alcohol

›Lowers seizure threshold

›Rest and adequate hydration

›Return to emergency department immediately for

›Seizure or recurrent seizure

›Call emergency services if seizure lasts > 5 minutes

›Sudden severe headache

›Worst headache of life, or rapidly worsening

›New weakness, numbness, or paralysis of face, arm, or leg

›Sudden vision changes or loss

›Confusion, difficulty speaking, or altered awareness

›Vomiting that prevents taking medications

›Fever with headache and stiff neck

›Follow-up appointments

›Infectious disease: within 2 to 4 weeks

›Review imaging and serology results

›Medication adjustment as needed

›Neurology: seizure management and AED follow-up

12References/r17

Guidelines and key sources

›Primary guidelines

›White AC, Coyle CM, Rajshekhar V, et al. Diagnosis and Treatment of Neurocysticercosis: 2017 Clinical Practice Guidelines by IDSA and ASTMH. Clinical Infectious Diseases. 2018. PMID available at PMC6248812

›Baird RA, Wiebe S, Zunt JR, et al. Evidence-Based Guideline: Treatment of Parenchymal Neurocysticercosis: American Academy of Neurology. Neurology. 2013. PMID 23568997

›Key references

›Garcia HH, Nash TE, Del Brutto OH. Clinical Symptoms, Diagnosis, and Treatment of Neurocysticercosis. Lancet Neurology. 2014. PMID 25453460

›Garcia HH, Del Brutto OH, Cysticercosis Working Group in Peru. Neurocysticercosis: Updated Concepts About an Old Disease. Lancet Neurology. 2005. PMID 16168934

›Cantey PT, Montgomery SP, Straily A. Neglected Parasitic Infections: What Family Physicians Need to Know. American Family Physician. 2021. PMID 34523888

›Pineda-Reyes R, White AC. Neurocysticercosis: An Update on Diagnosis, Treatment, and Prevention. Current Opinion in Infectious Diseases. 2022. PMID 35665719

›Veeravigrom M, Thampratankul L. Neurocysticercosis in Children. Pediatric Clinics of North America. 2022. PMID 34794669

›Cochrane systematic reviews

›Walton D, Castell H, Collie C, et al. Antiepileptic Drugs for Seizure Control in People With Neurocysticercosis. Cochrane Database of Systematic Reviews. 2021

›Monk EJM, Abba K, Ranganathan LN. Anthelmintics for People With Neurocysticercosis. Cochrane Database of Systematic Reviews. 2021

›Diagnostic criteria reference

›Del Brutto OH. Diagnostic criteria for neurocysticercosis, revisited. Pathog Glob Health. 2012

›ICD-10 B69.0 cysticercosis of central nervous system

›ICD-10 B69.1 cysticercosis of eye

›ICD-10 B69.89 cysticercosis of other sites including subcutaneous

Evidence & Review

Evidence & Review