Dextromethorphan Associated Neurotoxicity with Cerebellar Edema (DANCE) Syndrome in Young Children: Neuroimaging Features.

Dextromethorphan toxicity in young children (especially those with age 4 years or younger) can have an extremely poor prognosis if untreated. However, if timely recognized and optimally managed, it can have a good clinical outcome despite significant initial insult. We present 3 pediatric cases (< 5 years old) with sudden unresponsiveness following ingestion of cough medications containing dextromethorphan. All these children showed cytotoxic edema in cerebellar hemispheres on MR brain, with diffusion restricting foci in supratentorial white matter in 2 patients. These features resemble the recently described acute opioid toxidrome in children, the POUNCE syndrome (Pediatric Opioid Use-associated Neurotoxicity with Cerebellar Edema). Hence, we name this entity "DANCE" (Dextromethorphan Associated Neurotoxicity with Cerebellar Edema) to increase the awareness of dextromethorphan toxicity in young children and the need to promptly recognize it to initiate optimal management.ABBREVIATIONS: POUNCE= Pediatric Opioid Use-associated Neurotoxicity with Cerebellar Edema; DANCE= Dextromethorphan Associated Neurotoxicity with Cerebellar Edema.

Familial hemiplegic migraine in Indian children-a tertiary center experience.

Familial hemiplegic migraine (FHM), an autosomal dominant subtype of hemiplegic migraine, is a channelopathy presenting with severe headache, visual field defect, paresthesia, unilateral motor deficit, encephalopathy, seizures and aphasia. This cross-sectional study was conducted over 10 months in children aged 1-18 years suspected of hemiplegic migraine at a tertiary care pediatric hospital. Fourteen children were screened and five children with genetically confirmed FHM were included. The symptoms in the study population were paroxysmal hemiparesis (5/5), headache (5/5) and focal seizures (1/5). The hemiplegia episodes lasted from 4 h to 7 days. The mean age at the onset of neurological symptoms was 6.8 ± 0.7 years and the mean age at diagnosis was 12.8 ± 1.7 years, with a mean delay of 6.1 ± 1.9 years for the diagnosis. Neuroimaging during acute episodes revealed accentuated gray, white differentiation in the contralateral cerebral hemisphere with mild effacement of sulcal spaces in T2/fluid-attenuated inversion recovery (FLAIR) images. Genetic testing revealed ATP1A2 mutations (FHM2) in 4/5 and SCN1A (FHM3) in 1/5 patients. All of them (5/5) were initiated on oral topiramate and had favorable treatment responses with a mean follow-up duration of 7 ± 1.4 months. Diagnosis of FHM is mainly clinical and can be confirmed by genetic analysis. Perfusion and diffusion-weighted MRI should be considered during acute headache episodes, as it is mostly normal in symptom-free periods. Routine MRI sequences like T1 weighted, T2 weighted, FLAIR and contrast remain normal even during acute attacks.

Primary Diffuse Leptomeningeal Melanomatosis in an Indian Child With Review of Literature.

BACKGROUND: Primary diffuse leptomeningeal melanomatosis (PDLM) is an extremely rare, aggressive malignant neoplasia of the central nervous system. We report the first case of pediatric PDLM from India. METHODS: A review of literature was done to describe the 15 pediatric cases reported so far. RESULTS: A 12-year-old male child presented with fever, vomiting, and headache for 2 months. Cerebrospinal fluid examination was normal. An MRI of the brain revealed hydrocephalus, for which antitubercular therapy was started and external ventricular drainage followed by ventriculoperitoneal shunt was done. Repeat MRI revealed a suprasellar lesion, nodular enhancement of cranial nerves along with dural enhancement of spinal cord with arachnoiditis, and long-segment myelomalacia. Repeat cerebrospinal fluid examination was negative for malignant cells. During biopsy, blackish dura with diffuse blackish deposits in ventricle were noted. Histopathological examination revealed tumor cells with intracytoplasmic coarse brown pigment melanoma, frequent mitotic figures, and immunohistochemistry testing was positive for human melanoma black-45 and MelanA, suggestive of PDLM. He expired 4 months after the diagnosis. CONCLUSION: Diagnosing PDLM can be daunting in light of its slow but malignant progression mimicking TBM leading to improper management. However, the absence of any supportive microbiological evidence and failure to respond to the standard antitubercular therapy with subsequent progression of the symptoms should prompt the need for finding an alternative diagnosis. A targeted molecular diagnosis and precision medicine may provide a favorable outcome in children with PDLM.