['A 34-year-old man presented with herpes simplex encephalitis (HSE), with magnetic resonance imaging (MRI) showing dense foci of restricted diffusion in the temporal lobe.', 'With treatment and clinical improvement, follow-up MRI done 8 days later showed complete resolution of the restricted diffusion abnormalities, whereas other MRI sequences suggested interval progression.'] Does magnetic resonance restricted diffusion resolution correlate with clinical improvement and response to treatment in herpes simplex encephalitis?