MRI axial fluid attenuation inversion recovery (FLAIR) images in 48 year old male with HIV showing generalised cerebral atrophy with diffuse white matter hyperintenisty signal change seen in the bilateral periventricular frontal and paroeto-occipital regions consistent with HIV encephalopathy.
Clinically it is usually presents with progressive dementia, initially cognitive impairment and later accompanied by motor symptoms like gait disturbance and tremor. Collectively this is called as AIDS dementia complex.
Histopathology may reveal subacute encephalitis, cerebral atrophy and demyelination.
CT - The sole finding in most of the patients may be cerebral atrophy. In progressive advanced patient may see periventricular confluent white matter hypodensities.
MRI- Cerebral atrophy, classical appearance of confluent, bilateral and symmetrical white matter lesions seen as diffuse white matter change in the periventricular regions and centrum semiovale, with relativesparing of the subcortical white matter and posterior fossa structures. These lesions shows hyperintense on T1 and iso to hypointense on T1 images. There will be no contrast enhancement or mass effect.
MR Spectroscopy shows decreased N Acetyl Aspartate and increased choline peaks and changes in the glutamate and glutamine levels.