Approximately 3 weeks after immunization, this patient developed acute cerebellar ataxia with cranial nerve since 05/06/2001, which has progressed over the last two days. He was seen in the Pediatric Neurology Clinic for gait ataxia. It was felt that the pt most likely had an acute cerebellar ataxia associated with his recent varicella immunizaiton. He was discharged home after the lumbar puncture. He vomited a few times, likely secondary to his anesthesia, and tolerated two breast-feedings overnight and slept well. At 6am his mother noticed a right eyelid droop and intermittent deviation of the right eye medially. He was able to look fully to the right, laterally, but they were unable to have him look superiorly; it was unclear if this was cooperation versus cranial nerve dysfunction. His ataxia also seemed to have worsened, so that he was now having  much more difficulty walking. And he got admitted to the hospital. A follow up report received 12/03/2001 adds: Info has been received from a physician concerning a 12 month old male with a history of gastroesophageal reflux disease (GERD) and no immunosuppression or recent exposure to varicella or other viruses. It was also noted that no one in the pt's household was reported to be ill in recent weeks. On 04/18/2001 the pt was vaccinated with the 1st dose of varicella virus vaccine live (Lot #630975/1061K) in the left leg. It was noted that no rash occurred at the injection site post-vaccination. Concomitant therapy included the 1st dose of measles virus vaccine live (+) mumps virus vaccine live (+) rubella virus vaccine live (second generation) (MSD), the fourth dose of Haemophilus B conjugate vaccine (+) hepatitis B vaccine recombinant (yeast) (MSD) (Lot #638136/1589K) into the left leg and the 4th dose of streptococcus pneumoniae vaccine (PREVNAR) (Lot #473349) in the right leg. On approximately 05/05/2001, 17 days post-vaccination, the pt developed a "wide-based gait." The child had difficulty standing (he was previously able to stand unassisted). The pt had to hold onto a wall in order to stand. The symptoms persisted for several days and the pt was taken to the ER on approximately 05/06/2001 and was examined by a neurologist. The pt had an MRI (without contrast) of the brain, which was negative. The pt was sent home from the ER the same day. The following morning, the symptoms persisted, and the parents of the pt also reported a "ptosis of the right eyelid" as well as "deviation of the right pupil." The pt was returned to the ER and admitted to the hospital. The pt was hospitalized for approximately a day and a half, and had another MRI of the brain, with contrast, which was again negative. A lumbar puncture on 05/07/2001 was also performed at the peak of the child's symptoms and a specimen was submitted for PCR analysis on 05/14/2001, and was negative for all VZV. The pt was discharged from the hospital on 05/09/2001. A definitive diagnosis was never made, though the ataxia was felt to be related to an undiagnosed viral infection. Follow-up on 05/19/2001 reported the pt was very much improved. The physician stated that the child was still "wobbly" however a full recovery was expected. Additional info has been requested.