Creutzfeldt-Jakob Disease

CJD is the commonest transmissible CNS degeneration—human spongiform encephalopathy. nvCJD may be a zoonosis ("mad cow disease"), but NOT casually contagious. Sporadic CJD can be iatrogenically transmitted via biopsies/cornea/dura grafts. Predominantly affects cortex/basal ganglia/spinal cord (corticostriatospinal degeneration). Onset after middle age; progressive dementia/myoclonus/pyramidal/extrapyramidal signs; death in months to 1 year. Pathology: spongiform change, neuronal loss, astrogliosis.

Common Symptoms

Insomnia; convulsion; poor concentration; fatigue; fatigue; twitching; dizziness; depression; vertigo

Causes and Pathogenesis

(1) Etiology: unconventional slow-virus agent = amyloid fibrils (SAF) composed of prion protein (PrP27-30). Properties: (a) extreme resistance to disinfection/heat (80-100°C)/UV/radiation; invisible by routine EM. (b) transmissible with years-decades incubation; degenerative pathology with amyloid plaques/gliosis but no inflammation/inclusion bodies; steadily progressive; no interferon. Inactivated only at 132°C/60 min, 10% NaOCl × 1 h, or 1 N NaOH × 30 min × 3 cycles. (2) Pathogenesis: Prusiner (1982) proposed prion protein (PrP) as the cause. PrP is a 253-aa glycoprotein on chromosome 20p; normal cellular PrP^c is α-helical, protease-K-sensitive, 30-33 kDa. Disease-associated PrP^sc (PrP^Es/CJD) is 27-30 kDa, 40% β-sheet, aggregates into 10-20 × 100-200 nm rods (SAF/prion liposomes), protease-K-resistant; accumulates in brain causing neuronal apoptosis/spongiosis. Iatrogenic CJD: transmission via contaminated electrodes/surgery/dura grafts/pituitary hormones. Familial CJD: PRNP mutation. Sporadic CJD: somatic mutation. Codon 129/180/210/208 polymorphisms modify phenotype. Pathology: (1) gross: brain atrophy (10-month average survival; a 9-year case weighed only 575 g), widened sulci, narrowed gyri, symmetric ventricular dilation; white matter grossly normal. (2) microscopy: spongiform vacuoles (1-50 µm) in gray matter; neuronal loss (layers III/V, occipital, thalamus, caudate/putamen); astrogliosis (without microglial nodules/phagocytosis); mild white-matter change; amyloid plaques mainly in cerebellar molecular layer (seen after >15 months). (3) EM: membrane-bound vacuoles, synaptic loss, secondary lysosomes, Rosenthal fibers; plaques = 7-10 nm radiating fibrils. (4) IHC with PrP antiserum: positive in 59% CJD/100% GSS; hydrolytic autoclaving improves sensitivity in short-course cases. (5) vCJD features: thalamic/basal ganglia involvement > cortex; widespread PrP deposition (occipital worst); plaque-like (not synaptic) IHC pattern.

Treatment

No effective treatment

Preventive Measures

No evidence of casual transmission via intact skin; tears/nasal/saliva/feces non-infectious; routine nursing exposure non-infectious. Focus: strict handling of brain tissue/blood/CSF/contaminated instruments; 132°C/60 min autoclave or 10% NaOCl × 60 min × 3 cycles or 1 N NaOH × 30 min × 3 cycles; incinerate dressings/autopsy tissue; disposable syringes; avoid skin/mucosal injury during phlebotomy/surgery.

Department to Visit

It is recommended to visit the Neurology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.