Neurodegenerative Atrophy: Brain Progression in Dementia

Coronal Cross-Section

Atrophy Severity Index: 0% (Normal Baseline)

Normal Cognition Preclinical / MCI Moderate Dementia Severe Neurodegeneration

Sulci & Gyri Alterations

Cortical gyri thin ("knife-edge" gyri) while sulci grooves widen due to massive superficial loss of neurons in neocortex layers II-IV.

Ventriculomegaly (Ex Vacuo)

The lateral and third ventricles balloon outwards to passively occupy volume vacated by lost subcortical and periventricular white matter.

Hippocampal Decimation

The hippocampus and entorhinal cortex suffer up to 40-50% shrinkage, severing circuit connections vital for forming new episodic memories.

Morphometric Biomarkers

Dynamic Estimation

Total Brain Mass 1,380 g (-0%)

Hippocampus Volume 100% intact

Ventricle Expansion Ratio 1.0x (Normal)

Neocortical Thickness 3.8 mm (Average)

Clinical Manifestation

Cognitively intact individual. Intact episodic and semantic memory; normal executive decision-making and spatial orientation.

Amyloid-β Plaque Deposition

Extracellular aggregation of $A\beta_{42}$ peptides forms insoluble plaques, damaging synaptic transmission.

Hyperphosphorylated Tau (NFTs)

Microtubule-stabilizing tau protein detaches, hyperphosphorylating into intracellular neurofibrillary tangles, collapsing axonal transport.

Synaptic Pruning & Apoptosis

Starved of neurotrophic support and triggered by chronic neuroinflammation (microgliosis), neurons trigger cell death cascades.

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Point at the ventricles, cerebral cortex, or temporal lobes on the canvas to inspect site-specific atrophy dynamics.