A case report of atypical hemiplegic migraine with nonheadache onset in a Chinese child

Background Hemiplegic migraine (HM) is an uncommon subtype of migraine with aura including motor weakness. The core symptoms of HM are headache and motor weakness. However, we report a rare case of atypical HM with nonheadache onset in a Chinese child who was misdiagnosed several times. Case presentation We report a Chinese boy whose onset was sudden when he was 3 years old. He presented with a variety of phenotypes, including fever, vomiting, alternating hemiplegia, and drowsiness, but no headache in the initial stages. Magnetic resonance imaging (MRI) demonstrated unilateral cerebral oedema during the initial episode of hemiplegia. These symptoms recurred many times. As the disease progressed, the patient developed episodic headache. The patient was misdiagnosed several times with encephalitis, alternating hemiplegia of childhood (AHC) and mitochondrial encephalopathy. Whole-exome next-generation sequencing revealed a de novo heterozygous missense mutation in the ATP1A2 gene(p.Gly715Arg) classified as pathogenic and eventually led to a diagnosis of HM when he was 11 years old. Flunarizine was subsequently administered, and no recurrence was found during follow-up. Conclusions HM in children may be atypical in the initial stage of the disease, which could manifest as fever, alternating hemiplegia and drowsiness but no headache at the onset. This could easily lead to misdiagnosis. With age, it may eventually manifest as typical HM. Therefore, attention should be given to differentiation in clinical practice.When similar clinical cases appear, gene detection is particularly important, which is conducive to early diagnosis and treatment.

Novel missense mutation in the ATP1A2 gene associated with atypical sporapedic hemiplegic migraine

Hemiplegic migraine (HM) is a rare subtype of migraine with aura in which attacks include transient motor weakness or hemiparesis that can last several days. HM is linked to mutations in three different genes, CACNA1A, ATP1A2 and SCN1A, which encode for ion transporters. The clinical spectrum includes atypical symptoms such as impaired consciousness, epileptic seizures, permanent cerebellar ataxia or mental retardation. We describe a novel mutation found in the ATP1A2 gene in a patient with late-onset HM. His attacks were characterised by motor weakness associated with altered mental status, diplopia and ataxia. He also showed up MRI abnormalities and incomplete response to prophylactic therapy with verapamil. Late-onset HM should be considered among the possible causes of focal neurological deficits even in older patients with cerebrovascular risk factors when a stroke appears to be more likely.

Differential effect of FHM2 mutation on synaptic plasticity in distinct hippocampal regions

Introduction Familial hemiplegic migraine 2 is a pathology linked to mutation of the ATP1A2 gene producing loss of function of the α2 Na+/K+-ATPase (NKA). W887R/+ knock-in (KI) mice are used to model the familial hemiplegic migraine 2 condition and are characterized by 50% reduced NKA expression in the brain and reduced rate of K+ and glutamate clearance by astrocytes. These alterations might, in turn, produce synaptic changes in synaptic transmission and plasticity. Memory and learning deficits observed in familial hemiplegic migraine patients could be ascribed to a possible alteration of hippocampal neuronal plasticity and measuring possible changes of long-term potentiation in familial hemiplegic migraine 2 KI mice might provide insights to strengthen this link. Results Here we have investigated synaptic plasticity in distinct hippocampal regions in familial hemiplegic migraine 2 KI mice. We show that the dentate gyrus long-term potentiation of familial hemiplegic migraine 2 mice is abnormally increased in comparison with control animals. Conversely, in the CA1 area, KI and WT mice express long-term potentiation of similar amplitude. Conclusions The familial hemiplegic migraine 2 KI mice show region-dependent hippocampal plasticity abnormality, which might underlie some of the memory deficits observed in familial migraine.

Targeted next generation sequencing identifies a genetic spectrum of DNA variants in patients with hemiplegic migraine

Objective: Hemiplegic migraine in both familial (FHM) and sporadic (SHM) forms is a rare subtype of migraine with aura that can be traced to mutations in the CACNA1A, ATP1A2 and SCN1A genes. It is characterised by severe attacks of typical migraine accompanied by hemiparesis, as well as episodes of complex aura that vary significantly between individuals. Methods: Using a targeted next generation sequencing (NGS) multigene panel, we have sequenced the genomic DNA of 172 suspected hemiplegic migraine cases, in whom no mutation had previously been found by Sanger sequencing (SS) of a limited number of exons with high mutation frequency in FHM genes. Results: Genetic screening identified 29 variants, 10 of which were novel, in 35 cases in the three FHM genes ( CACNA1A, ATP1A2 and SCN1A). Interestingly, in this suspected HM cohort, the ATP1A2 gene harboured the highest number of variants with 24/35 cases (68.6%), while CACNA1A ranked the second gene, with 5 variants identified in 7/35 cases (20%). All detected variants were confirmed by SS and were absent in 100 non-migraine healthy control individuals. Assessment of variants with the American College of Medical Genetics and Genomics guidelines classified 8 variants as pathogenic, 3 as likely pathogenic and 18 as variants of unknown significance. Targeted NGS gene panel increased the diagnostic yield by fourfold over iterative SS in our diagnostics facility. Conclusion: We have identified 29 potentially causative variants in an Australian and New Zealand cohort of suspected HM cases and found that the ATP1A2 gene was the most commonly mutated gene. Our results suggest that screening using NGS multigene panels to investigate ATP1A2 alongside CACNA1A and SCN1A is a clinically useful and efficient method.

Familial Hemiplegic Migraine with Severe Attacks: A New Report withATP1A2Mutation

Introduction. Familial hemiplegic migraine (FHM) is a rare disorder characterized by migraine attacks with motor weakness during the aura phase. Mutations in CACNA1A, ATP1A2, SCN1A, and PRRT2 genes have been described.Methods. To describe a mutation in ATP1A2 gene in a FHM case with especially severe and prolonged symptomatology.Results. 22-year-old woman was admitted due to migraine-type headache and sudden onset of right-sided weakness and aphasia; she had similar episodes in her childhood. Her mother was diagnosed with hemiplegic migraine without genetic confirmation. She presented with fever, decreased consciousness, left gaze preference, mixed aphasia, right facial palsy, right hemiplegia, and left crural paresis. Computed tomography (CT) showed no lesion and CT perfusion study evidenced oligohemia in left hemisphere. A normal brain magnetic resonance (MR) was obtained. Impaired consciousness and dysphasia began to improve three days after admission and mild dysphasia and right hemiparesis lasted for 10 days. No recurrences were reported during a follow-up of two years. We identified a variant in heterozygous state in ATP1A2 gene (p.Thr364Met), pathogenic according to different prediction algorithms (SIFT, PolyPhen2, MutationTaster, and Condel).Conclusion. Prolonged and severe attacks with diffuse hypoperfusion in a FHM seemed to be specially related to ATP1A2 mutations, and p.T364M should be considered.

Perfusion and pH MRI in familial hemiplegic migraine with prolonged aura

Introduction To investigate tissue flow disturbance and hypoxia during migraine aura, we studied a case of familial hemiplegic migraine (FHM) using novel magnetic resonance imaging (MRI) techniques. Case results A 44-year-old male was admitted with suspected stroke because of confusion and aphasia. Initial gadolinium-based perfusion MRI showed a decrease in cerebral blood flow and an increase in capillary flow disturbances within the left hemisphere. Later during the prolonged aura phase, chemical exchange saturation transfer MRI indicated a drop in pH in the affected area. The patient was diagnosed with an R908Q mutation in the ATP1A2 gene causing FHM type 2. Discussion During prolonged aura in FHM, MRI shows reduced CBF, capillary flow disturbances and a possible pH drop that could indicate tissue hypoxia.