Neuropathology and Neurodegeneration
Mechanisms of neurological disease
Cell death and dysfunction
Neuropathology encompasses excitotoxicity, oxidative stress, mitochondrial failure, protein misfolding, demyelination, vascular injury, and immune-mediated damage. Advanced diagnosis often requires integrating clinical signs with imaging, biomarkers, pathology, and genetics.
Which pathological process is strongly associated with Alzheimer's disease?
Alzheimer's disease is classically associated with amyloid-beta accumulation and tau pathology.
Correct answer: Amyloid and tau pathology
Define excitotoxicity.
Overactivation can drive calcium overload and downstream damage.
Correct answer: Neuronal injury or death caused by excessive excitatory neurotransmission, often involving glutamate.
Demyelinating disease
Loss of myelin disrupts saltatory conduction and can produce sensory, motor, and autonomic symptoms. Inflammatory demyelinating disorders may show dissemination in time and space, whereas hereditary leukodystrophies often reflect genetic defects in myelin maintenance.
Major disease mechanisms
Neurodegeneration
- Progressive loss of neurons or synapses
- Often linked to protein aggregation and aging
Demyelination
- Primary myelin loss with conduction failure
- May be inflammatory or genetic
Biomarkers
Fluid and imaging biomarkers are increasingly used to detect disease before irreversible network loss occurs.
Why is early biomarker detection valuable in neurodegenerative disease?
Earlier detection may improve stratification and treatment timing.
Correct answer: It can identify pathology before substantial irreversible neuronal loss occurs.
Which mechanism most directly impairs saltatory conduction?
Myelin loss slows conduction and disrupts efficient signal propagation.
Correct answer: Demyelination