Sudden onset of the movement disorder  ataxia  , often following an infectious viral disease.
                    
                 
                  
                 
                
                
               
               
                
                    
                        Alternative Names
                    
                                   Cerebellar ataxia; Ataxia - acute cerebellar; Cerebellitis; Acute cerebellar ataxia of childhood        
                    
                 
                
                    
                        Causes, incidence, and risk factors
                    
                          Acute cerebellar ataxia is most common in children, especially those younger than 3 years old. It often occurs several weeks after a viral illness. Common predisposing infections include  chickenpox   and Coxsackie viral illnesses. In adults, the most common infectious causes are Epstein-Barr virus and Mycoplasma infections.  Ataxia may affect movement of the trunk (axial) or limbs.  Axial ataxia   is characterized by a broad-based  unsteady gait   (walking style). When the child is sitting, the trunk may deviate side-to-side and back-to-front or any of these combination and then return to the vertical position in a jerky type of motion. Jerky eye movements ( nystagmus  ) and jerky explosive speech ( dysarthria  ) may develop at the same time.  Limb ataxia manifests itself with poor fine motor control of the hands or legs and appears as though the person is able to coordinate his or her movements. For example, a hand may sway back and forth when reaching for an object.  The condition usually subsides without treatment over a period of weeks to months. Occasionally, a child will be left with a persistent movement disorder or behavioral problem.
                    
                 
                
                    
                        Signs and tests
                    
                                   The diagnosis of acute cerebellar ataxia is made by excluding other causes of  ataxia  , and by taking a history of a recent illness.  Tests may include:   
 Cerebrospinal fluid studies (  CSF total protein  ) 
CT or MRI scan of the head
                    
                 
                
                    
                        Expectations (prognosis)
                    
                                   Full recovery usually occurs without treatment within a few months.        
                    
                 
                
                    
                        Complications
                    
                                   Movement or behavioral disorders may (rarely) persist.        
                    
                 
                
                    
                        Calling your health care provider
                    
                                   Call your health care provider if any symptoms of  ataxia   appear.