ABSTRACT
Acute disseminated encephalomyelitis (ADEM) is rare autoimmune
neurological multifocal disorder characterised by inflammatory
demyelination of brain and spinal cord usually in response to infection
or sequelae of immunisation, most commonly affecting the children.Though
a rare one it is estimated that 1 in 125,000-250,000 population is
affected by ADEM each year. And such a case of 15 years old girl
presented with acute onset of fever and headache and single episode of
seizure followed by unconsciousness with GCS 6(E2V2M2).signs of
meningeal irritation like neck rigidity, Kernig’s sign and Brudzinski’s
sign were positive. investigation report showed Hb-11.4 g/dl
,neutrophlic leukocytosis , normal range of serum electrolytes ,ICT for
malaria was negative and MRI of brains showed multiple abnormal T2
hyperintense signal in both parieto-frontal white matter. so she was
diagnosed a case of ADEM and treated with intravenous methylprednisolone
for 5 days followed by oral corticosteroid in tapering dose for 6 weeks.
Introduction
ADEM also known as post -infectious encephalomyelitis is a rare
autoimmune inflammatory neurological disorder of nervous system mainly
central which is characterised by demylination of the brain and spinal
cord as a result of infection or sequelae of immunisation. Children are
the most affected one but adult case of ADEM occurs following
vaccination against Mumps,Measles and rubella(1)(2) . Though rare one
estimated of 1 in 125,000-250,000 individuals are affected by ADEM each
year(1). More commonly male are the most affected one with a male and
female ratio of 1.3 to 1.The risk factors for ADEM include genetics,
exposure to infectious organisms,immunization exposure and lighter skin
pigmentation. All the ethnic groups are affected globally. The majority
of cases follow either viral or bacterial infection and in majority of
cases causative pathogen is unidentified(1). The pathogenesis is not
fully understood but antigentic exposure in genetically susceptible
individuals may cause ADEM either through molecular mimicry and or due
to T cell mediated immune mechanism. It has also been suggested that
ADEM may occur due to CNS injury secondary to generalised inflammation
of brain and spinal cord(4).ADEM patients usually have presentation like
rapid onset of fever, headache ,nausea or vomiting confusion, fatigue
and neurological features like numbness, difficulty swallowing, vision,
seizure, difficult in coordinating voluntary movements such as walking
and some degree of impairment of consciousness(1)(3). Though there is no
diagnostic criteria for ADEM but presence of signs and symptoms and
radiological findings can help in diagnosis of ADEM. In patients with
ADEM T2-Weighted and FLAIR magnetic resonance imaging ( MRI) of brain
shows bilateral,hyperintense lesion that are diffuse and poorly
demarcated(4).ADEM being a autoimmune disease treatment includes I/v
Methyl prednisolone at dosage of 20 to 30 mg/kg (max 1g/day) for 3 to 5
days followed by oral corticosteroids in a tapering dose for 4 to 6
weeks.(5). Full recovery is seen in 50 to 70% of cases and ranging of
70 to 90% with some minor residual disability. In some case severity
ranges to 8 to 30% with ataxia and hemiparesis.(6)
Case report;
We hereby present a case of 15 years old girl brought to the Mymensingh
Medical College by her parents with the complaints of fever and headache
for 3 days. Fever was high grade ,acute in onset without any chills and
rigor with no evening rise of temperature . Headache was severe and
prolonged for 3 days following which she suddenly developed single
episode of seizure followed by unconsciousness for which she was brought
to the hospital.
On examination she had altered consciousness with GCS
6(E2V2M2),Temperature was raised, blood pressure was 100/80 mm of Hg and
signs of meningeal irritation like neck rigidity, Kernig’s sign and
Brudzinski’s sign were positive and bilateral planter extensor was
found.Other systematic examination findings were normal. As per the
clinical findings she was treated for meningoencephalitis with
Inj.Ceftriaxone 1g I/V BD, inj. Acyclovir 250mg 1 vial I/v BD
,inj.dexamethasone 1 amp i/v TDS and investigation showed
Hb-11.4 g/dl with increased sedimentation, neutrophilic leukocytosis
with WBC Count 25000/mm^3 and 87% of neutrophils, Serum electrolytes
and blood glucose were within the normal limit.
ICT for malaria was negative .
MRI OF BRAIN revealed. -Multiple abnormal T2 hyperintense signal in both
parieto-frontal white matter suggestive of acute disseminated
encephalomyelitis(ADEM)