disorder It is the most common cause of acute motor paralysis in children GBS occurs when activated immune mechanisms, induced by an antecedent viral infection, trigger inflammation and demyelination (see Chapter 97 Neurologic Emergencies ) Many viruses have been implicated, including adenovirus, Epstein–Barr virus, cytomegalovirus, human immunodeficiency virus, varicellazoster virus, measles virus, Rubulavirus (mumps), and vaccinia virus Mycoplasma pneumoniae and Campylobacter jejuni infections, as well as some vaccines (i.e., swine flu 1976), have also been implicated The most common complaint is weakness, but patients also present with leg and back pain, and in younger children, an abnormal gait The symptoms may progress for days to weeks The weakness is usually symmetric and may be ascending or descending There is often a sensory loss, as well as loss of position and vibratory sense DTRs are diminished or absent in the weak muscles Bowel and bladder incontinence, autonomic dysfunction (hypotension), and cardiac dysrhythmias also occur Respiratory paralysis occurs in 20% to 30% Cranial nerve involvement is seen in 30% to 40% of patients, usually manifested by facial weakness or ocular paresis The Miller Fisher variant of GBS includes the triad of ataxia, areflexia, and ophthalmoplegia Required clinical criteria for diagnosis include a progressive motor weakness of more than one limb, and areflexia Examination of the cerebrospinal fluid demonstrates an elevated protein without pleocytosis (albuminocytologic dissociation) Important diseases to consider in the differential diagnosis include acute cerebellar ataxia, transverse myelitis, toxic neuropathy, tick paralysis, botulism, myasthenia gravis (MG), and acute viral myositis A chronic form of GBS, chronic inflammatory demyelinating polyneuropathy (CIDP), also exists The course of CIDP varies widely and ranges from complete spontaneous recovery to frequent relapses with gradually declining function Therapies for both GBS and CIDP include steroids, IVIG, plasmapheresis, and physiotherapy Acute flaccid myelitis (AFM) is a newly discovered condition in which a child has rapid onset of flaccid limb weakness in one or more limbs There is consensus that this disease occurs in the setting of enterovirus infection, but the relative contributions of direct viral injury and postinfectious inflammatory response are still being actively evaluated Diagnosis is made based on MRI showing grey matter changes spanning one or more vertebral segments or cerebral spinal fluid pleocytosis (>5 cells/mm3) A negative MRI within the first 72 hours of symptom onset does not rule out the disease Though treatments for similar diseases like GBS have been considered, such as IVIG and steroids, there is not enough