ADEM is an “inflammatory demyelinating illness of the central nervous system[1], usually manifesting in children and is linked to multifocal brain lesions and encephalopathy.” The diagnostic evaluation includes neuroimaging to determine the extent of the CNS involvement, along with spinal and serum fluid tests to investigate viral and inflammatory etiology. Minor pleocytosis with increased protein may be seen in CSF analysis. Pediatric ADEM is one of a collection of conditions known as acquired demyelinating syndromes (ADSs)[2], which are defined by a sudden or gradual onset of neurological impairments associated with signs of inflammatory demyelination of CNS, including the optic nerves. Here we report an atypical presentation of ADEM in an 11-year-old child.

An 11-year-old child presented with  complaints of fever for 15 days, pain abdomen for 1 week, neck pain with inability to walk for 3 days and urinary incontinence for 1 day. Systemic examination done revealed hypotonia in lower limbs with hyporeflexia and  intact sensory system. MRI brain with spine done revealed - scattered T1 iso-hypo and T2/FLAIR white matter hyperintense areas noted in bilateral frontal, temporal and left parietal lobe , the spinal cord had T2 hyperintensity noted involving the spinal cord extending from C2 to D4 vertebral body level predominately involving central and posterior cord with mild cord swelling, suggestive of ADEM. The child was started on Intravenous Methyl Prednisolone, the urinary bladder was catheterized and other supportive management was provided. The child improved gradually over a period of 3 months with a tapering dose of oral steroids. The child attained complete bladder control and was able to walk again independently.

ADEM is mainly diagnosed through clinical and radiological evaluation since there are no specific laboratory investigations to confirm the same. “The International Pediatric Multiple Sclerosis Study Group defines ADEM with the following criteria”[3]: a) “a polyfocal clinical CNS condition presumed to have an inflammatory demyelinating cause”, b) “exclusion of meningitis”, c) “no new clinical or MRI findings appearing 3 months or more after the onset”, and d) “an abnormal brain MRI during the acute phrase (3 months)”. Typically, clinical presentation and MRI lesions associated with ADEM will improve after short immunotherapy. Most of acute neurological deficit resolve by 3 months post-attack. Associated brain lesions show significant improvement or complete resolution on neuroimaging. To assess the progression of ADEM lesion, it is recommended for a follow-up MRI brain at 3–6 months and confirm the regression in a typical ADEM pattern.

To address any possible neurological or psychosocial effects of the ADEM, long-term follow-up is essential[1]. According to research conducted by Paolilo et al.[2], around 25% of children hospitalized with ADEM require admission to the intensive care unit. The mortality rate for ADEM has been reported to be between 1% and 3%. Despite variations in evaluation methods across different ADEM studies, the majority of patients (50-80%) achieve full recovery with a normal neurological examination. 

Immunotherapy is regarded as a conventional treatment and may help patients recover more quickly and have better results than in the past, yet there isn't enough conclusive data to support this theory[4]. Children with ADEM typically recover completely, usually in 4-6 weeks.

According to research by Li et al.[5], the clinical presentation of ADEM varies based on the areas affected by demyelination. Majority of the patients showed a polyfocal clinical presentation with multifocal neurological deficits. Early symptoms included fever, headache, nausea and vomiting. Since fever is uncommon in other demyelinating diseases like MS, its presence can support an ADEM Diagnosis. Motor deficits such as hemiplegia, paraplegia, and quadriplegia, observed over three-fifths of patients are the most common clinical features, suggesting frequent involvement of pyramidal tract lesions. Ataxia is another common clinical feature, which is less frequent in Multiple Sclerosis. 

Intravenous immunoglobulins, plasma exchange, and corticosteroids are the current therapy options for ADEM. The initial treatment involves administrating a high dosage of IV corticosteroids, specifically methylprednisolone, for three to five days at a dose of 20 to 30 mg/kg per day, with a maximum dose of 1 g per day. This should be followed by three to six weeks of oral prednisolone. If a patient does not respond to steroid therapy, other treatment options for ADEM include plasma exchange and IV immunoglobulin, administered at a dose of 2 grams/kg over 2-4 days. ADEM generally has an excellent long-term prognosis. 

A case report by Balamurugesan et al.[6] on a rare occurrence of acute disseminated encephalomyelitis (ADEM) triggered by Escherichia coli infection, involved a 6-year-old girl who developed neurological symptoms following a urinary tract infection, ultimately leading to the diagnosis of ADEM through MRI findings. Hence ADEM can present atypically and should be kept as one of the differential diagnoses in children presenting with neurological symptoms.

ADEM can manifest atypically with lower-limb hypotonia or loss of bladder control. A high degree of suspicion and neuroimaging are essential for identifying and managing these individuals.

I would like to thank patient and his attenders for their cooperation. I would like to thank department of paediatrics for providing me this opportunity and constant support.