Five children with “Alice in Wonderland” syndrome associated with infectious mononucleosis are reported from Assaf Harofeh Medical Center, Zerifin, and Sheba Medical Center, Tel Aviv University, Israel. Visual evoked potentials (VEP) were studied during and after symptoms which included episodes of visual illusions - distortion of form, size, position, movement, or color - associated with headache, nausea, and dizziness. The episodes lasted 5 to 20 minutes and occurred 6 to 23 times daily. During the disease, VEPs showed statistically high amplitudes of P100-N145 compared to the control group, similar to findings in migraine. EEGs showed occipital high-voltage sharp or slow waves in 3 patients, between episodes. After recovery, repeat studies were normal. MRI or CT were normal. A focal decrease in cerebral perfusion is postulated as the pathophysiologic abnormality. 
COMMENT. Alice in Wonderland syndrome, or metamorphopsia, associated with abnormal visual evoked potentials, is reported in infectious mononucleosis. It is also described in patients with migraine and epilepsy, and during acute febrile states. Cerebral perfusion PET studies have demonstrated decreased perfusion in regions near the visual tract and visual cortex in 4 children with this syndrome. 
Polymerase chain reaction in CNS infections. The clinical use of cerebrospinal fluid PCR in the diagnosis of infectious neurologic viral diseases is reviewed from the University of Colorado Health Sciences Center, Denver . PCR and detection of minute amounts of DNA or RNA in various tissues or fluids may help to identify infectious causes of diseases of previously undetermined etiology. It may also differentiate recurrent viral infection (PCR-positive) from post-infectious immune-mediated disease (PCR-negative).