Acute Disseminated Encephalomyelitis Follow-up

• After initial evaluation and initiation of therapy, further inpatient care is dictated by the evolution of disease and rate of recovery exhibited by the patient.
• Physical and occupational therapy may be indicated in patients with paresis, ataxia, low vision, and other focal neurologic abnormalities that impair function.
• Provision for feeding and for the treatment of abnormalities of bowel or bladder function may be indicated.
• When seizures occur, they usually do so transiently at the onset of disease. In rare instances, additional management issues for seizures arise during the subsequent course of treatment.

• Outpatient care indications depend on the course of illness and the extent of recovery at the time of discharge. It may include the involvement of physical, occupational, or speech therapists. Some patients require follow-up with urologists or gastroenterologists because of persistent bladder or bowel problems.
• Patients who are placed on tapering doses of oral corticosteroids require follow-up to ascertain the rate and extent of improvement. Urgent return or consultation may be warranted by patients who display relapse during taper of corticosteroids. In such instances, the relapse is usually controlled by restoration of a higher medication dosage with slower ensuing taper. Some difficult cases require slow tapers.

• Some patients with more severe degrees of neurologic disability are transferred to rehabilitation facilities for some period of time before they are judged sufficiently recovered to be discharged home.

Acute hemorrhagic leukoencephalitis, which Dorothy Russell demonstrated to be at the severe end of the spectrum of ADEM-like illnesses, may be observed in certain infectious illnesses such as measles encephalitis. This and other possible examples of severe ADEM-spectrum illness may be prevented by immunization.

Recently, several factors have been suggested to modify risk for multiple sclerosis.

• A factor that may reduce the risk for such autoimmune illness is the type and degree of early childhood infectious illness, due to favorable effects on the early childhood development of immunoregulatory function.
• Suggestions have also been made about potential positive effects of early childhood sun exposure via vitamin D-related effects on immunoregulatory function.

Prevention of early childhood illnesses that might have favorable effects on immunoregulation and reduced sun exposure may be elements that account for what appears to be a dramatic increase in prevalence of certain forms of autoimmune illness over the past 4 decades in wealthier countries of the world. These assertions have provoked scientific investigation of considerable interest, but the conclusions remain incompletely verified and their relevance to ADEM remains quite uncertain.

• The most common inpatient complications include abnormalities of vision, motor function (ie, pyramidal, extrapyramidal, cerebellar), or bladder or bowel function.
• Recurrence is the chief outpatient complication and is rare.

• The outlook for recovery is generally excellent. Although some older series suggest up to a 10% mortality rate, only 1.5% of the authors' cases have resulted in mortality due to ADEM-related complications. Degree of recovery is unrelated to severity of illness. Complete recovery may be observed even in children who become blind, comatose, and quadriparetic. Recovery is poorest in children younger than 2 years, patients with myelitis, and those who have significant edema of the brain or spinal cord. Whether ultra–high-dose corticosteroid therapy and other treatments for edema might improve the outcome for these groups is not yet known, although limited experience suggests this possibility. In other cases of ADEM, modest visual or motor deficits may persist, as may sphincter abnormalities in patients with spinal cord disease. Disturbances of mood and personality may outlast motor deficits, but they may also wane over ensuing months.
• The long-term (10-y follow-up) risk of patients with ADEM for development of MS is 25%. Risk for MS is highest in children whose ADEM onset was (1) afebrile, (2) without mental status change, (3) without prodromal viral illness or immunization, (4) without generalized EEG slowing, or (5) associated with an abnormal CSF immune profile (Rust, 1989).
• Most patients who experience a bout of ADEM can look forward to complete recovery or the persistence of only mild deficits, such as modestly diminished visual acuity. This excellent outlook even applies to patients who experienced a global low state of function during the acute illness.

  • Whether any available form of treatment has a favorable effect on the time to maximal recovery or the risk for deficits is unknown. Exceptions to the excellent outlook are patients with transverse myelitis and infants younger than 2 years. Cord swelling may account for the high rate of residual paresis and the occasional death of patients with severe acute inflammatory myelitis. Prompt administration of high doses of corticosteroids can possibly improve the outlook for these patients, but no reliable data yet support this hypothesis. The risk of MS for prepubertal children who have a bout of ADEM is less than 10%.
  • The authors have observed children with a typical bout of ADEM in the first decade of life who manifest MS during the second decade, after a symptom-free hiatus of more than 10 years.
• In the authors' experience, the risk for MS for children who have had a single prepubertal bout of ADEM is less than 6%. MS is defined, for these children, as persistence of an illness satisfying clinically definite multiple sclerosis (CD-MS) criteria into adolescence.

  • The risk for MS in children who have had 1-3 prepubertal relapses of ADEM, none of which was related to steroid withdrawal, ranges from 15-33%. Risk increases in proportion to the number of relapses that occur, especially relapses that occurred without exogenous provocation (eg, febrile prodrome, vaccination).
  • Children with more than 3 prepubertal clinical relapses are at significant risk of having rare vasculitic or inflammatory processes that must be diagnosed by biopsy of brain tissue or other organs (eg, CNS vasculitis, hypersensitivity vasculitides, sarcoidosis, histiocytic lymphogranulomatosis) and in some instances are found to be harboring neoplasm (the results of their imaging studies having been misinterpreted).
• The hesitancy to apply a diagnosis of CD-MS has not prevented the authors from using immunomodulatory therapy (eg, IFN-beta1a) in the treatment of children with recurrences or persistent lesions that do not appear to respond to corticosteroid therapy or those who develop a pattern suggesting steroid dependence (steroid withdrawal–related recurrence); the sometimes gratifying response to IFN-beta1a has not been viewed as confirmation of MS.

  • These uncertainties have generated several additional worries, particularly whether too much delay is entailed in administration of immunomodulatory therapy to a prepubertal child for whom an MS diagnosis is withheld and whether at some point discontinuing immunomodulatory therapy is safe in a child who has experienced a good response to such therapy for a recurrent illness that may be MS despite the absence of characteristic changes in the CSF immune profile.
  • In this context, remember that as many as 8% of adults who are identified as having CD-MS do not have immune profile abnormalities even after the second or third clinical bout.

• For excellent patient education resources, see eMedicine's Brain and Nervous System Center and the article Multiple Sclerosis. All these materials may be printed free of charge.