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Introduction Acute disseminated encephalomyelitis (ADEM) can represent a diagnostic challenge for clinicians, as many disorders (inflammatory and noninflammatory) have a similar clinical and radiologic presentation. The diagnosis of ADEM depends on the history, physical examination, and supplemental neuroimaging. Acute disseminated encephalomyelitis is an immunologically mediated inflammatory disease of the central nervous system (CNS) resulting in multifocal demyelinating lesions affecting the gray and white matter of the brain and spinal cord.[1] Acute disseminated encephalomyelitis should be adequately defined and distinguished from other diseases affecting the white matter. In particular, a diagnostic challenge lies in distinguishing multiphasic forms of ADEM from multiple sclerosis (MS). Available diagnostic criteria do not reliably distinguish it from first presentations of relapsing diseases such as MS and neuromyelitis optica. Pediatric patients meeting Mikaeloff et al. criteria for ADEM presented at a mean age of 7.1 years versus a mean of 12.0 years for MS.[2] However, complete differentiation between the two diseases is impossible on a single magnetic resonance imaging (MRI) examination.[3] This is especially important, not only for prognostic purposes, but for therapeutic purposes, since a diagnosis of MS carries the recommendation for early treatment with immunomodulators.

However, complete differentiation between the two diseases is impossible on a single magnetic resonance imaging (MRI) examination.[3] This is especially important, not only for prognostic purposes, but for therapeutic purposes, since a diagnosis of MS carries the recommendation for early treatment with immunomodulators. Some pediatric patients with inflammatory demyelinating CNS disorders cannot be classified under any of the established disease entities, making their treatment and prognosis difficult. Guillain–Barré syndrome (GBS) is the most common cause of acute flaccid paralysis in healthy infants and children.[4] Most pediatric groups have used IV methylprednisolone (10–30 mg/kg/day, maximum dose of 1 g/day) or dexamethasone (1 mg/kg) for 3–5 days followed by oral steroid for 4–6 weeks with full recovery reported in 50–80% of patients.[56] Case Report A 10-year-old boy presented with inability to walk since 2 days with difficulty in swallowing, dysphonia and drooling of saliva. There was no history of recent infection, fever, diarrhea, convulsions or trauma or recent immunization. His antenatal, postnatal details were not significant. On clinical evaluation, he was conscious and irritable. Neurological examination revealed the generalized hypotonia; weakness started with lower limbs then progressed to involve both upper limbs. However, respiration was normal. The anterior abdominal muscles were weak, and the patient could support himself with difficulty in sitting position. He had lower motor neuron type of facial paralysis.

ion revealed the generalized hypotonia; weakness started with lower limbs then progressed to involve both upper limbs. However, respiration was normal. The anterior abdominal muscles were weak, and the patient could support himself with difficulty in sitting position. He had lower motor neuron type of facial paralysis. The patient had irritability and fundoscopy was suggestive of bilateral papilledema. Hence, cerebrospinal fluid analysis was deferred in our patient. He was treated for raised intracranial pressure with mannitol and 3% NaCl. Emergency computed tomography (CT) scan head was done which revealed vasogenic edema in bilateral fronto-parietal and left temporal regions and infarcts. Further evaluation with MRI study was suggested. Magnetic resonance imaging brain study was done based on CT scan findings MRI revealed white matter lesions in the brain, pons and thoracic levels of the spinal cord. It revealed peripherally enhancing lesions in right fronto-parietal and left fronto-temporo-parieto-occipital region involving grey and white matter, subcortical region and corpus callosum; suggestive of ADEM. Multiple altered signal intensity areas, largest size 5.3 cm × 3.6 cm, were seen involving grey matter and bilateral periventricular deep white matter [Figure 1]. Figure 1 Magnetic resonance imaging showed peripherally enhancing lesions in right fronto-parietal and left fronto-temporo-parieto-occipital region involving grey and white matter, subcortical region and corpus callosum; acute disseminated encephalomyelitis

Magnetic resonance imaging brain study was done based on CT scan findings MRI revealed white matter lesions in the brain, pons and thoracic levels of the spinal cord. It revealed peripherally enhancing lesions in right fronto-parietal and left fronto-temporo-parieto-occipital region involving grey and white matter, subcortical region and corpus callosum; suggestive of ADEM. Multiple altered signal intensity areas, largest size 5.3 cm × 3.6 cm, were seen involving grey matter and bilateral periventricular deep white matter [Figure 1]. Figure 1 Magnetic resonance imaging showed peripherally enhancing lesions in right fronto-parietal and left fronto-temporo-parieto-occipital region involving grey and white matter, subcortical region and corpus callosum; acute disseminated encephalomyelitis Electro-diagnosis showed an important reduction of conduction velocity that is, mild generalized motor sensory axonal polyneuropathy (acute motor and sensory axonal neuropathy-GBS). Fundus evaluation revealed bilateral optic neuritis after 3 weeks of illness [Figure 2a and b]. However, there was no clinical deterioration of vision or retro-orbital pain. Figure 2 (a and b) Visual evoked potential suggestive of bilateral optic neuritis Based on clinical findings and electromyography-nerve conduction velocity, a diagnosis of GBS was made and based on MRI findings and fundoscopy, concurrent diagnosis of ADEM and GBS was considered. Hence, the treatment followed with intravenous immunoglobins (2 g/kg) for 2 days and intravenous methylprednisolone (30 mg/kg/day) for 3 days.

Based on clinical findings and electromyography-nerve conduction velocity, a diagnosis of GBS was made and based on MRI findings and fundoscopy, concurrent diagnosis of ADEM and GBS was considered. Hence, the treatment followed with intravenous immunoglobins (2 g/kg) for 2 days and intravenous methylprednisolone (30 mg/kg/day) for 3 days. There was gradual improvement in motor power to 3/5 within about 2 weeks. The patient showed significant clinical improvement after 4 weeks and could stand with support and walk with assistance. The patient was advised physiotherapy and discharged on oral steroids prednisolone at (1 mg/kg/day) in tapering doses over 4 weeks period. However, this could be considered as the first episode of MS with optic neuritis, therefore, our patient will be evaluated on follow-up for further episodes and treatment with immunomodulators. Discussion Acute disseminated encephalomyelitis is an immunologically mediated inflammatory disease of the CNS resulting in multifocal demyelinating lesions affecting the gray and white matter of the brain and spinal cord. To avoid further misdiagnosis and to develop a uniform classification, the international pediatric MS study group proposed a consensus definition for ADEM for application in both research and clinical settings [Table 1]. Table 1 International MS study group-monophasic ADEM criteria[1] We have reported a case of the practical approach for management of patients suspected of having ADEM when the diagnosis is uncertain.

Discussion Acute disseminated encephalomyelitis is an immunologically mediated inflammatory disease of the CNS resulting in multifocal demyelinating lesions affecting the gray and white matter of the brain and spinal cord. To avoid further misdiagnosis and to develop a uniform classification, the international pediatric MS study group proposed a consensus definition for ADEM for application in both research and clinical settings [Table 1]. Table 1 International MS study group-monophasic ADEM criteria[1] We have reported a case of the practical approach for management of patients suspected of having ADEM when the diagnosis is uncertain. Building on clinicopathological and retrospective studies of ADEM, Mikaeloff et al. have applied the most restricted definition of ADEM to date in a prospective study of children: The occurrence in a previously healthy child of acute symptoms associating the following at onset: More than one neurological deficit, change in mental state; and any combination of alterations seen on MRI, providing that these included white matter lesions.[7] Guillain–Barré syndrome is an acute inflammatory polyradiculoneuropathy characterized by rapidly progressive, essentially symmetric weakness, areflexia, and the time to the full progression is 4 weeks.[8] It now ranks as the most frequent cause of acute flaccid paralysis. The annual incidence of GBS is reported to be 1.2–2.3/100,000.[9]

Guillain–Barré syndrome is an acute inflammatory polyradiculoneuropathy characterized by rapidly progressive, essentially symmetric weakness, areflexia, and the time to the full progression is 4 weeks.[8] It now ranks as the most frequent cause of acute flaccid paralysis. The annual incidence of GBS is reported to be 1.2–2.3/100,000.[9] The main features of GBS are rapidly progressive bilateral and relatively symmetric weakness of the limbs with or without involvement of respiratory muscles or cranial nerve-innervated muscles.[1011] Patients with GBS differ from each other regarding the extent and distribution of weakness, and the presence of autonomic dysfunction, sensory symptoms and cranial nerve deficits. Multiple clinical factors should be considered in combination before arriving at a probable diagnosis of ADEM including: Presenting signs and symptoms Conventional and advanced MRI abnormalities Sufficient follow-up (as long as 10 years) based on clinical and/or neuroimaging criteria Lack of alternative diagnosis, concurrent diagnosis Brain histopathology when available. Concurrent ADEM and GBS are uncommon with few reported cases presenting with severe neurological morbidity. Prompt recognition and treatment can hasten the recovery and, therefore, improve the neurological outcome. Source of Support: Nil. Conflict of Interest: None declared.