片側痙攣・片麻痺・てんかん症候群

INTRODUCTION AND OBSERVATIONS: Hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome is a rare complication of prolonged focal status epilepticus in childhood. The typical course follows a complex febrile convulsion and status epilepticus, typically in a child under 4 years of age, accompanied by cytotoxic edema of one hemisphere, evolving secondarily to atrophy and refractory seizures. We present a case series from Mayotte Island, providing a clinical and radiological chronological picture of this neurological disorder, with Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scans taken at different stages of the disease. CONCLUSION: HHE syndrome is a rare clinic-radiological syndrome that complicates prolonged febrile illness. Understanding the spontaneous evolution of this pathology makes it possible to limit explorations and even to project on the long-term prognosis, in the absence of known therapies.

Hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome is a rare pediatric epilepsy syndrome characterized by prolonged focal febrile seizures, postictal hemiparesis, and progressive unilateral brain injury, often followed by chronic epilepsy. We report a previously healthy 10-month-old girl who presented with a prolonged left-sided focal fever-associated seizure. She tested positive for SARS-CoV-2 but did not meet criteria for multisystem inflammatory syndrome in children. On admission, she had left-sided flaccid hemiparesis. Brain MRI showed mild diffusion restriction and marked hyperperfusion of the right hemispheric gray matter, most prominently in the frontal, temporo-occipital, and hippocampal regions. EEG showed high-amplitude slowing over the right hemisphere without epileptiform discharges. No further seizures occurred, and long-term antiseizure treatment was not required. At 9-month follow-up, the patient was seizure-free and developmentally age-appropriate, but the hemiparesis persisted. Serial MRI showed progressive right hemispheric cortical and subcortical atrophy and hippocampal sclerosis. Extensive diagnostic workup found no other structural, infectious, or metabolic cause. This case illustrates the classical biphasic course of HHE syndrome and highlights the diagnostic value of early MRI, EEG, and genetic testing. The patient carried a paternally inherited heterozygous IRF3 variant, a gene essential for innate antiviral immunity. Although causality cannot be established, the temporal association with SARS-CoV-2 infection and an IRF3 variant suggests a possible genetic predisposition to infection-triggered injury. Continued clinical vigilance and long-term follow-up are essential, as epilepsy develops in most children with HHE. Greater awareness of this syndrome may support earlier recognition and timely rehabilitation to optimize functional outcomes.

This case report describes a unique case of hemiconvulsion-hemiplegia-epilepsy syndrome in a paediatric patient with an underlying hypomyelinating leukodystrophy. We present the clinical, neuroimaging and genetic findings of a 3-year-old girl with a myelin deposition disorder who presented with a prolonged febrile status epilepticus, followed by persistent left hemiplegia. Brain magnetic resonance imaging (MRI) revealed a pattern consistent with hemiconvulsion-hemiplegia-epilepsy syndrome, with unilateral cytotoxic oedema and increased cerebral blood flow in the right cerebral hemisphere cortex. The girl was treated with corticosteroid therapy and levetiracetam. Follow-up imaging showed cerebral atrophy ipsilateral to the seizure focus. Incomplete myelination pattern remained unchanged. No prior cases associating hypomyelinating leukodystrophy with hemiconvulsion-hemiplegia-epilepsy syndrome have been reported. This case expands the phenotypic spectrum of hypomyelinating disorders and raises the hypothesis that an underlying white matter vulnerability may predispose to or modify the course of hemiconvulsion-hemiplegia-epilepsy syndrome. Recognition of such associations may have implications for prognosis and management, including seizure control strategies and neurorehabilitation. Further reports are needed to determine the role of myelination in the development of epileptic syndromes.

Introduction and Importance: Dyke-Davidoff-Masson syndrome (DDMS) is a rare neurological condition characterized by focal or generalized drug-resistant epilepsy, hemiparesis, face or body asymmetry with atrophy, and cognitive impairment in early childhood and adulthood. DDMS is generally diagnosed in the paediatric age group. Neuroimaging shows skull bone thickening with cerebral hemiatrophy and hyperpneumatization of sinuses. Case Presentation: Here is a case of a middle-aged female presenting with a history of multiple episodes of seizure since childhood. MRI showed diffuse atrophy of the left cerebral hemisphere with hypertrophy of the contralateral hemisphere, hyperpneumatization of the left frontal sinus, and thickened calvaria, all characteristics of DDMS. Based on the history, clinical findings, and MRI reports, it was diagnosed as a case of DDMS. Discussion: DDMS can be due to injury to the brain, either intrauterine or during early childhood. The features can be confused with other conditions like Rasmussen encephalitis, hemiconvulsion-hemiplegia-epilepsy (HHE syndrome), Sturge-Weber syndrome, Silver-Russell syndrome, basal ganglia germinoma, Fishman syndrome, and linear nevus syndrome. Before making a diagnosis, a proper antenatal and postnatal history with early childhood presentations should be taken. Occupational therapy, physiotherapy, and seizure control improve the patient's quality of life. Conclusion: Though DDMS is usually diagnosed during early childhood, a few missed cases lead to later findings in life, resulting in late medical consults and affecting an individual's lifestyle. Management includes only symptomatic relief. Paediatricians, radiologists, neurologists, and gynaecologists need to be well-informed about the case for its early diagnosis and management.