HIV effects on age-associated neurocognitive dysfunction: premature cognitive aging or neurodegenerative disease?

Table 1 Summary of neurocognition, neuroimaging, neuropathology, and pathophysiology of brain disturbances in HIV and Alzheimer’s disease

	HIV	Alzheimer’s disease	Both
Neurocognitive manifestations	Psychomotor slowing	Primary amnestic disturbance	Memory disturbances
	Executive dysfunction	Anomia
	Selective cognitive impairments	Global cognitive dysfunction
Cerebral volumetric changes	Early declines in basal ganglia and frontal lobe volumes	Greater cortical atrophy and ventricular enlargement	Early white matter changes
DTI findings	Early frontal lobe changes	Early hippocampal changes	Globally decreased FA
MRS findings	Elevated Cho		Decreased NAA
MRS findings	Elevated Cho		Elevated MI
Aβ	Diffuse	Neuritic	Occur in neocortical areas
Aβ	Extracellular and intracellular	Primarily extracellular	Occur in neocortical areas
pTau			Elevated in medial temporal lobe
CSF markers	Inconsistent Tau findings	Elevated pTau	Decreased amyloid
ApoEε4		Robust relationship with cognitive dysfunction and dementia risk	Increases risk for Aβ, cerebral atrophy, cognitive dysfunction, and disease progression
BBB			Altered function
Glucose metabolism	Increased in basal ganglia	Decreased in parieto-temporal areas, posterior cingulate cortices, and medial temporal lobes
Glucose metabolism	Decreased in frontal lobes
Mitochondrial function			Impaired
Neurotoxicity			Increased
Oxidative stress			Increased
Inflammation			Increased
Vascular and metabolic influences	May occur as a result of HIV		Exacerbate cognitive effects
Vascular and metabolic influences	May occur as a result of HIV		Increase Aβ burden

Findings common to both diseases are listed, along with findings unique to each. Aβ, beta-amyloid; ApoEε4, apolipoprotein-E ε4; BBB, blood–brain barrier; Cho, choline; CSF, cerebrospinal fluid; DTI, diffusion tensor imaging; FA, fractional anistropy; MI, myoinositol; MRS, magnetic resonance spectroscopy; NAA, N-acetylaspartate; pTau, hyperphosphorylated tau.

ISSN: 1758-9193