In herpes encephalitis, all of the following are true, except

Harrison&;s principles of internal medicine 17 th edition. *Focal finding in patient with encephalitis should always raise the possibility of HSV encephalitis .examples of focal findings include(1) areas of increased signal intensity in the frontotemporal ,cingulate or insular region of brain on T2 weighted,FLAIR or diffuse weighted MRI images (2)focal areas of low absorption on mass effect and contrast enhanced on CT (3)periodic focal temporal lobes spikes on background of slow flattened activity on EEG *80%cases have abnormality in temporal lobe *CT is less sensitive than MRI.