12/7-12/10: minor cold, nose congestion, sneezing, minor throat pain, temp less than 100.5, no drugs, resolved on its own. 12/13: Patient vaccinated. He has been feeling great for 2-3 days after his last cold, so Dr. decided he is well enough to be vaccinated. Maybe this was a poor decision in retrospect, in parents' opinion. 12/15: Patient started feeling lethargic, complained of fatigue, congestion returned again, with minor throat pain. 12/16: Patient woke up tired in the morning, refused his milk and breakfast. He laid on the couch for 4 hours and refused his lunch, saying he is tired and not hungry. He had very mild fever (100 or so). I (dad) took him to urgent care where he was tested for flu (negative) and strep (positive). Discharged with Amoxicillin and 150ml of MOTRIN. Felt better that afternoon, ate 2 full meals, went to bed around 8pm, slept a full night. 12/17: Loss of speech and mobility. Patient woke up super lethargic and tired. When I tried talking to him, his speech was slurred, and his steps were wobbly. Rushed him to ER where they ran a slew of tests on him (blood, strep, CT, Spinal Tap, see below). Spinal tap came back with elevated white blood cells, no initial indication of bacterial growth. Patient's neurological condition was deteriorating quickly (unable to speak or walk properly). By 1-2pm he was transferred to hospital, main floor. By 4pm, he was conscious but not responding to stimuli or cues, including me calling his name. He was transferred to the ICU unit for neurological assessment and monitoring. By end of that day, patient was semi conscious. The diagnosis was Encephalitis, but still no infective agent found. Temp that night about 103F. 12/18: Patient woke up showing more conscious signs but still pretty bad mobility, jittery limbs, jittery head and neck, not talking and not making any sounds.  Cognitively he was not very responsive except to me (dad) and his mom. HHV-6 positive in his CSF but negative in blood, Drs ruled out HHV-6 as potential infection. MRI performed with sedation and contrast at 5pm, results shows hyperintensities suggestive of brain inflammation in brain stem, deep gray matter, basal ganglia. Patient has another dip in mental state, showing little response, not nodding or responding to parents. Fever that day was mild (less than 101 F). Everyone is very concerned about deteriorating state. 12/19 to 12/20: All antibiotic and antiviral drugs are stopped, further blood tests showed no evidence of any active viral or bacterial infection. We ask for patient to be placed on NG tube for nutrition. Patient starts improving slightly cognitively on 12/20, starts playing some games but only for 5-10 mins. Very lethargic still, unable to stand on legs (tested by PT). PICU staff become less concerned about seizure risk. Patient is moved out of PICU to main floor at end of 12/20. Still, patient has not spoken a word, and is unable to sit himself up, walk nor stand, and is in diapers. Medical staff expecting a very slow recovery lasting months, and thus started referral process to rehab. Temps less than 99F. 12/21 to 12/22: More or less same state as on 12/20. Patient is very irritated, although smiles and interacts more with books and games. Started showing more and more signs of cognition. Patient says one word on 12/21 at night (yes, twice, as response to question). On 12/21, Drs and specialists recommend we try IVIG treatment, which starts on 6pm on 12/22. Drs say that IVIG takes about 3-4 days to show any effect, still predicted that patient would need long term rehab. IVIG administered for 2 days. 12/23: Patient wakes up, starts vocalizing some numbers when playing cards with dad. He later walked assisted with me from bed to bathroom door. Improved cognitive response. By end of day, patient was very cognitively aware. 12/24 and 12/25: An avalanche of recovery: Patient recovered 50 to 60% of his speech, is walking minimally assisted to unassisted on 12/25. Patient ran 10 yards on 12/25.  Still tired and fatigued but with improved cognitive response. Started eating purées and soups.  IV removed. Drs calling his recovery 'crazy.' 12/26: Another spike of spontaneous improvement:  Patient is walking unassisted, running around hospital. NG tube removed. Patient discharged, does not qualify for in-patient rehab. Official diagnosis is Meningoencephalitis although no infections were found, neurologist thinks this is a post-infective process but, cannot be 100% sure.  Neurologist recommended an autoimmune serum test (results negative on 1/2/2019). Patient home with follow-up appointments with neurologist and outpatient rehab in a week. 12/28: Patient's speech is almost back to normal. Walking is very stable, but loses balance every now and then, so he is closely monitored at home. He is very irritable compared to before. He is suffering from sensitivity to light and noise. Cries much more than before. Still not sure if this is chronic or not. Hopefully this goes away with time. Week of 1/1/2019: Patient is back to about 100% his energy, functional and cognitive abilities. Remaining minor sensitivity to noise, light, and irritability, are slowly improving with time. Infectious disease specialist, neurologist as well as patient's PCP recommended we report this incident to VAERS.