Acute Disseminated Encephalomyelitis : Paediatric Neurology

1. Nishan Perera
Group 4
TSMU

2. Acute disseminated encephalomyelitis (ADEM),
is also known as postinfectious
encephalomyelitis sometimes.
It is a demyelinating disease of the central
nervous system that typically presents as a
monophasic disorder associated with multifocal
neurologic symptoms and disability.
 A mean age of between 5-8 years.

3. Acute disseminated encephalomyelitis (ADEM) is a neurological,
immune-mediated disorder in which widespread inflammation of
the brain and spinal cord damages tissue known as white matter.
White matter is tissue composed of nerve fibres, many of which
are covered by a collection of fats and proteins known as myelin.
Myelin, which collectively may be referred to as the myelin sheath,
protects the nerve fibres, acts as an insulator and increases the
speed of transmission of nerve signals.
Damage to the myelin sheath affects the nerve’s ability to transmit
information and potentially can cause a wide range of neurological
symptoms.
INTRODUCTI
ON

4. The exact cause of ADEM is
not known.
Many researchers suggest that ADEM may represent an abnormal
immune reaction directed against the body’s own tissues (autoimmune
disorder).
In autoimmune disorders, the body’s natural defences (e.g., antibodies,
lymphocytes) against substances that are perceived as foreign (antigens)
inappropriately begin to attack healthy tissues, for unknown reasons.

5.  In approximately 50-75 percent of ADEM cases, the
inflammatory attack is preceded by a viral or bacterial
infection. The inflammatory attack and neurological
symptoms often begin within a couple of weeks after
the viral or bacterial illness.
Large number of viruses associated with these
infections, including :
• Measles , Mumps, Rubella
• Varicella zoster, Epstein-Barr, Cytomegalovirus
• Herpes simplex, Hepatitis A, Influenza
• Enterovirus infections.

6. *Less than 5 percent of ADEM cases follow
immunization.
Currently the measles, mumps and rubella
vaccinations are the most commonly associated
vaccinations with post- vaccineADEM.
Neurological symptoms typically appear 4 to 14 days
after the immunization has been done.

7. Categories ofADEM
1.MonophasicADEM
*Any new or changing symptoms within this three
month period is considered as one event.
* Is a one-time episode that can develop over a
period for as long as three months.
* Symptoms that might occur during an oral steroid
taper or within one month of the completion of the
taper are also classified as one single episode.

8. *Is defined as a subsequent attack that involves the
same symptoms that occurred during the initial
attack.
*The MRI findings tend to be similar to the initial
attack, and there are no lesions, but there could be
an enlargement of the lesions from the original
episode

9. 3. MultiphasicADEM
*There must be signs of encephalopathy, but symptoms
and neuroimaging findings are in different areas from
the initial attack.
*There might be new lesions evident on MRI and there
might also be evidence of partial or complete resolution of
the lesions associated with the first episode

10. Fever, Headache, and Vomiting
Encephalopathy is a characteristic feature of
ADEM and usually develops rapidly.
Signs and Symptoms

11. Encephalopathy results in symptoms, such as:
* Altered level of consciousness (lethargy →coma)
* Acute cognitive dysfunction
* Behavioral changes
* Seizures
In about ⅓ of those diagnosed.
Other common neurologic signs of ADEM
include:
* Long tract pyramidal signs
*Acute hemiparesis
*Cerebellar ataxia
*Cranial neuropathies

13. A diagnosis is made based upon identification of
characteristic symptoms, a detailed patient history, a
thorough clinical evaluation and a variety of specialized
tests including imaging techniques such as magnetic
resonance imaging (MRI).
An MRI can demonstrate characteristic brain lesions in
individuals with ADEM. Additional tests to exclude other
conditions may also be performed. Such tests may include
infectious, immunologic, and metabolic tests.

14. * An ADEM diagnosis is considered when
individuals develop multifocal neurologic
abnormalities with:
o Excessive irritability
o Confusion
o Altered level of consciousness
(encephalopathy)
Especially if the onset of symptoms occurs
within 1 to 2 weeks after a viral/bacterial
infection or a vaccination

15. Axial T2-weighted FLAIR
MRI of the brain in a child
with acute disseminated
encephalomyelitis (ADEM).

17. Children with ADEM typically present with
fever, meningeal signs, acute
encephalopathy, and evidence of
inflammation in blood and cerebrospinal
fluid.
Thus, consideration should be given to
treatment with broad-spectrum antibiotics and
acyclovir until an infectious etiology is
excluded.

18. 1. high-dose intravenous glucocorticoids.
2. intravenous immunoglobulin.
3. plasma exchange.
 However, the effectiveness of these treatments
forADEM has not been definitively confirmed,
as there are no prospective clinical trial data to
determine optimal treatment, including dose or
duration.

19. In the only study that compared these two
treatments for
ADEM
intravenous methylprednisolone (n=21) was associated
with a modestly better outcome, as measured by the
median Expanded Disability Status Scale, than
intravenous dexamethasone (n=25), and the difference
was statistically significant .
The strength of this result is limited by
small patient numbers, lack of
randomization, and lack of blinded
treatment or assessment.

20. Data from small case series and case reports
suggest that intravenous immune globulin
(IVIG) is beneficial as rescue therapy in
patients with ADEM who fail to respond to
methylprednisolone or as initial therapy .
Dosing of IVIG in these studies ranged from 1- 2
g/kg given
either as a single dose or divided over 3 – 5 days
.

21.  Limited data suggest that plasma exchange is beneficial
in children with ADEM who fail treatment with IVIG and/or
methylprednisolone .
 The largest series was retrospective and reported
improvement following plasma exchange in six
children with ADEM who did not respond to initial
treatment with glucocorticoids followed by IVIG .
 In another retrospective study, plasma exchange
demonstrated some benefit for patients with idiopathic
transverse myelitis when used in combination with iv
glucocorticoids.
 Therefore, it may be of particular benefit for patients
withADEM associated with myelopathy .

22. Although no consensus exists, some experts
suggest obtaining at least two additional MRIs
after the 1st normal MRI,
 over a period of at least 5 years from the
initial episode
ofADEM
 to confirm the absence of new
inflammatory demyelinating
lesions .

23. Most children with ADEM make a full recovery,
usually slowly
over 4 – 6 weeks.
At follow-up, approximately 60 - 90 % have
minimal or no neurologic deficits .
Although modern studies of ADEM in children
report little or no mortality, earlier studies
suggested that the mortality of postinfectious
ADEM was as high as 5 %.
The extent and site of lesions on the initial MRI do
not predict

24. the following case series illustrate the range of
outcomes for children withADEM:
The largest study included 84 children from Argentina
withADEM.
At a mean follow-up of 6.6 years, the neurologic
examination was either normal or detected minor
abnormalities but no associated disability in 75
children (89 %).
 Residual deficits in the remaining children included :
 mild to severe hemiparesis,
 mild paraparesis,
 partial epilepsy,
 reduced visual acuity, and
 mental handicap.

25. In a report from Australia, 31 children withADEM
were followed
for an average of 18 months .
Complete recovery occurred in 25 (81 %).
Mild abnormalities were detected in the remaining
6 patients; these included
recurrent headaches,
behavioral problems,
esotropia,
subtle hemiparesis, and
 minor gross motor abnormalities.

26.  DONE BY NISHAN PERERA
 TSMU
 GROUP 4