consider discharge home mildly symptomatic, well appearing child with history and exam consistent with postinfectious cerebellitis with excellent follow-up (give injury prevention precautions)
otherwise, admission indicated for further workup, observation
Ataxia 
Systemic conditions
Dysphonia
Intoxications with diminished alertness
Dysphagia
Ethanol
Diplopia
Sedative/hypnotic toxicity