Profound encephalopathy with complete recovery in three children with familial hemiplegic migraine

[Developmental and epileptic encephalopathy produced by the ATP1A2 mutation]

A case of DEE98, a rare developmental and epileptic encephalopathy related to previously reported the de novo missense mutation p.Arg908Gln in the ATP1A2 gene, is described. A girl examined first time in 11 months had microcephaly, severe mental and motor delay, strabismus, spastic paraparesis and pachypolymicrogyria on brain MRI that is atypical for DEE98. Epilepsy with polymorphic seizures started at the age of 15 months. There was a remission lasting 9 months, after which seizures renewed. DEE98 was diagnosed at the age of 2 years 9 months by exome sequencing verified by trio Sanger sequencing. Another finding from high-throughput exome sequencing were two previously undescribed heterozygous variants of uncertain pathogenicity in the SPART gene, which causes autosomal recessive spastic paraplegia type 20 (SPG20); Sanger sequencing confirmed the trans position of the variants. The common clinical sign with typical SPG20 was early spastic paraparesis with contractures; other symptoms did not coincide. Considering the phenotypic diversity of SPG20 and the possibility of a combination of two independent diseases, we performed an additional study of the pathogenicity of SPART variants at the mRNA level: pathogenicity was not confirmed, and there were no grounds to diagnose SPG20.

Association between acute complications in PMM2-CDG patients and haemostasis anomalies: Data from a multicentric study and suggestions for acute management

OBJECTIVES

Patients with PMM2-CDG develop acute events (stroke-like episodes (SLEs), thromboses, haemorrhages, seizures, migraines) associated with both clotting factors (factor XI) and coagulation inhibitors (antithrombin, protein C and protein S) deficiencies. The aim of the study was to correlate acute events to haemostasis and propose practical guidelines.

METHODS

In this multicentric retrospective study, we evaluated clinical, radiological, haemostasis and electroencephalography data for PMM2-CDG patients hospitalized for acute events. Cerebral events were classified as thrombosis, haemorrhage, SLE, or "stroke mimic" (SM: normal brain imaging or evoking a migraine).

RESULTS

Thirteen patients had a total of 31 acute episodes: 27 cerebral events with 7 SLEs, 4 venous thromboses, 4 haemorrhages (3 associated with thrombosis), 15 SMs at a mean age of 7.7 years; 4 non-cerebral thromboses, one of which included bleeding. A trigger was frequently involved (infection, head trauma). Although sometimes normal at baseline state, factor XI, antithrombin and protein C levels decreased during these episodes. No correlation between haemostasis anomalies and type of acute event was found.

DISCUSSION

Acute events in PMM2-CDG are not negligible and are associated with haemostasis anomalies. An emergency protocol is proposed for their prevention and treatment (https://www.filiere-g2m.fr/urgences). For cerebral events, brain Magnetic Resonance Imaging with perfusion weight imaging and diffusion sequences, electroencephalogram and haemostasis protein levels guide the treatment: anticoagulation, antithrombin or fresh frozen plasma supplementation, antiepileptic therapy. Preventing bleeding and thrombosis is required in cases of surgery, prolonged immobilization, hormone replacement therapy.

CONCLUSION

Acute events in PMM2-CDG are associated with abnormal haemostasis, requiring practical guidance.

Early onset severe ATP1A2 epileptic encephalopathy: Clinical characteristics and underlying mutations

BACKGROUND

ATP1A2 mutations cause hemiplegic migraine with or without epilepsy or acute reversible encephalopathy. Typical onset is in adulthood or older childhood without subsequent severe long-term developmental impairments.

AIM

We aimed to describe the manifestations of early onset severe ATP1A2-related epileptic encephalopathy and its underlying mutations in a cohort of seven patients.

METHODS

A retrospective chart review of a cohort of seven patients was conducted. Response to open-label memantine therapy, used off-label due to its NMDA receptor antagonist effects, was assessed by the Global Rating Scale of Change (GRSC) and Clinical Global Impression Scale of Improvement (CGI-I) methodologies. Molecular modeling was performed using PyMol program.

RESULTS

Patients (age 2.5-20 years) had symptom onset at an early age (6 days-1 year). Seizures were either focal or generalized. Common features were: drug resistance, recurrent status epilepticus, etc., severe developmental delay with episodes of acute severe encephalopathy often with headaches, dystonias, hemiplegias, seizures, and developmental regression. All had variants predicted to be disease causing (p.Ile293Met, p.Glu1000Lys, c.1017+5G>A, p.Leu809Arg, and 3 patients with p.Met813Lys). Modeling revealed that mutations interfered with ATP1A2 ion binding and translocation sites. Memantine, given to five, was tolerated in all (mean treatment: 2.3 years, range 6 weeks-4.8 years) with some improvements reported in all five.

CONCLUSIONS

Our observations describe a distinctive clinical profile of seven unrelated probands with early onset severe ATP1A2-related epileptic encephalopathy, provide insights into structure-function relationships of ATP1A2 mutations, and support further studies of NMDAR antagonist therapy in ATP1A2-encephalopathy.

Stroke-Like Episodes in PMM2-CDG: When the Lack of Other Evidence Is the Only Evidence

Phosphomannomutase 2 deficiency (PMM2-CDG) is the most frequent congenital disorder of glycosylation. PMM2-CDG patients develop chronic cerebellar atrophy as a neurological hallmark. However, other acute neurological phenomena such as stroke-like episodes (SLE), epilepsy, migraine, and cerebrovascular events, may also occur, and they are frequently the cause of disability and impaired quality of life. Among these, SLE are among the most stressful situations for families and doctors, as their risk factors are not known, their underlying pathomechanisms remain undiscovered, and clinical guidelines for diagnosis, prevention, and treatment are lacking. In this paper, the recent SLE experiences of two PMM2-CDG patients are examined to provide clinical clues to help improve diagnosis through a clinical constellation of symptoms and a clinical definition, but also to support a neuroelectrical hypothesis as an underlying mechanism. An up-to-date literature review will help to identify evidence-based and non-evidence-based management recommendations. Presently neuropediatricians and neurologists are not capable of diagnosing stroke-like episodes in an unequivocal way, so there is still a need to perform invasive studies (to rule out other acute diseases) that may, in the end, prove unnecessary or even harmful. However, reaching a correct and early diagnosis would lead not only to avoidance of invasive tests but also to better recognition, management, and understanding of the disease itself. There is a great need for understanding of SLE that may ultimately be very informative for the detection of patients at risk, and the future development of preventive and management measures.

Familial Hemiplegic Migraine With Progressive Cerebellar Ataxia Caused by a p.Thr666Met CACNA1A Gene Mutation in a Chinese Family

Here, we describe the first case of familial hemiplegic migraine type 1 (FHM1) resulting from a T666M mutation in the CACNA1A gene of a Chinese individual. A 54-year-old female patient demonstrated extensive clinical manifestations, including transient paropsia, hemianesthesia, logaphasia, hemiplegia, migraine, fever, impaired consciousness, and progressive cerebellar ataxia. At admission, neurological examination showed a fever of 38.6°C, coma, bilateral pupillary constriction, left-sided deviation of both eyes, meningeal irritation, and bilateral positive Chaddock's sign. Brain magnetic resonance imaging (MRI) displayed only cerebellar atrophy. The pressure and white blood cells of the cerebrospinal fluid (CSF) were elevated. Her nine relatives also had similar clinical spectra. To further clarify the diagnosis, we conducted a genetic analysis on the family. The results of genetic testing showed that all seven living affected members carried the T666M mutation in the CACNA1A gene. This case report indicates that the diagnosis of FHM should be taken into account when a patient manifests migraine accompanied with hemiplegia, acute encephalopathy, and abnormal CSF. In addition, genetic testing is indispensable for the identification of some atypical attacks of hemiplegic migraine.

Encephalopathy in a Large Cohort of British Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy Patients

Background and Purpose- Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of stroke usually presenting with migraine with aura, lacunar infarcts, and cognitive impairment. Acute encephalopathy is a less recognized presentation of the disease. Methods- Data collected prospectively from 340 consecutively recruited symptomatic patients with diagnosis of CADASIL seen in a British National CADASIL clinic was retrospectively reviewed and original clinical records and imaging obtained. An encephalopathic event was defined as an acute event of an altered state of consciousness in a patient with CADASIL, manifesting with signs of brain dysfunction, which warranted hospital admission in the absence of any other cause. Clinical characteristics, risk factors, and outcome of encephalopathic presentations were studied. Results- A total of 35 of 340 (10.3%) participants had a history of 50 encephalopathic events which was the first hospital presentation of CADASIL in 33 (94.3%) patients. Most commonly reported features during episodes were visual hallucinations (44%), seizures (22%), and focal neurological deficits (60%).Complete recovery within 3 months was reported in 48(96%) episodes. In 62% of episodes, there was a history of migraine or migraine aura directly preceding the encephalopathy. In 2 out of 15 cases where magnetic resonance imaging during episodes was available, unilateral focal cortical swelling was seen. A past history of migraine was independently associated with encephalopathy (odds ratio=12.3 [95% CI, 1.6-93.7]; P=0.015). Conclusions- In up to 10% of CADASIL patients, a reversible encephalopathy is the first presentation leading to diagnosis. The strong association with migraine suggests a shared pathogenesis. Focal cortical swelling may be seen on magnetic resonance imaging during the acute episode.

Stroke-Like Episodes and Cerebellar Syndrome in Phosphomannomutase Deficiency (PMM2-CDG): Evidence for Hypoglycosylation-Driven Channelopathy

Stroke-like episodes (SLE) occur in phosphomannomutase deficiency (PMM2-CDG), and may complicate the course of channelopathies related to Familial Hemiplegic Migraine (FHM) caused by mutations in CACNA1A (encoding Ca_V2.1 channel). The underlying pathomechanisms are unknown. We analyze clinical variables to detect risk factors for SLE in a series of 43 PMM2-CDG patients. We explore the hypothesis of abnormal Ca_V2.1 function due to aberrant N-glycosylation as a potential novel pathomechanism of SLE and ataxia in PMM2-CDG by using whole-cell patch-clamp, N-glycosylation blockade and mutagenesis. Nine SLE were identified. Neuroimages showed no signs of stroke. Comparison of characteristics between SLE positive versus negative patients' group showed no differences. Acute and chronic phenotypes of patients with PMM2-CDG or CACNA1A channelopathies show similarities. Hypoglycosylation of both Ca_V2.1 subunits (α_1A and α_2α) induced gain-of-function effects on channel gating that mirrored those reported for pathogenic CACNA1A mutations linked to FHM and ataxia. Unoccupied N-glycosylation site N283 at α_1A contributes to a gain-of-function by lessening Ca_V2.1 inactivation. Hypoglycosylation of the α₂δ subunit also participates in the gain-of-function effect by promoting voltage-dependent opening of the Ca_V2.1 channel. Ca_V2.1 hypoglycosylation may cause ataxia and SLEs in PMM2-CDG patients. Aberrant Ca_V2.1 N-glycosylation as a novel pathomechanism in PMM2-CDG opens new therapeutic possibilities.

Fifteen-minute consultation: Approach to the child with an acute confusional state

Acute confusional state (ACS) refers to sudden impairment of cognitive function and represents a major medical emergency. The impairment may be global or confined specifically to a particular faculty of higher mental function, such as memory. This review highlights the importance of relevant medical history and clinical signs and symptoms in reaching the correct diagnosis. In this review, we have presented a diagnostic approach to a child presenting with ACS and described commonly encountered causes, their treatments and outcomes. We have also presented an algorithm for the diagnostic approach to the child with ACS.

Pediatric hemiplegic migraine: role of multiple MRI techniques in evaluation of reversible hypoperfusion

BACKGROUND

Hemiplegic migraine (HM) is a rare type of migraine with aura that involves motor weakness. Data on conventional and advanced neuroimaging findings during prolonged attacks of HM are limited, particularly in children.

CASE

A 13-year-old-female with a history of migraine had a typical attack of HM characterized by right-sided hemiplegia, deterioration of vigilance and paraphasia. MRI performed 3 hours after hemiplegia onset revealed normal diffusion tensor imaging (DTI) sequences, but perfusion weighted imaging (PWI) showed a large area of hypoperfusion within the left cerebral hemisphere and susceptibility weighted imaging (SWI) demonstrated a matching area with prominent, hypointense draining sulcal veins. Magnetic resonance angiography (MRA) revealed subtle narrowing of the left middle cerebral artery. The neuroimaging abnormalities completely resolved 24 hours after the attack onset.

CONCLUSION

Multiple conventional and advanced MRI techniques including SWI play a key role in an HM attack to (1) exclude acute arterial ischemic stroke and (2) further understand the pathophysiology of HM.

'Possessed': acute confusional migraine in an adolescent, prevented by topiramate

Acute confusional migraine (ACM) is recognized as a rare, but highly disabling migraine equivalent, mostly reported in children and adolescents. Herein we describe the case of a 12-year-old girl admitted to hospital for an acute confusional state and severe psychomotor agitation, associated with a pulsating headache and nausea, which turned out to be a manifestation of ACM. The girl was discharged on topiramate prophylaxis, titrated up to 75 mg/die; no recurrence of confusional and/or headache episodes has been reported over the last 14 months to date. Due to the rarity of this clinical entity, only anecdotal reports about acute and prophylactic treatment of ACM are available in the literature. The case reported herein suggests that topiramate seems to be effective in ACM prophylaxis, although a longer observation period in our patient and more cases are needed to confirm any long-term clinical benefit.

Sporadic hemiplegic migraine presenting as acute encephalopathy

A 10-year-old boy with psychomotor developmental delay and cerebellar vermis atrophy developed right hemiplegia with vomiting, unconsciousness, convulsions, and late-onset fever. Slow delta activity was noted over the left hemisphere on electroencephalography, and neuroimaging revealed swelling of the left temporo-occipital cerebral cortex with restricted diffusivity, successive transient cortical atrophy, and hyperperfusion over the left cerebral hemisphere. Interleukin-6 was elevated in the cerebrospinal fluid. The acute symptoms resolved completely within 3 weeks after onset, but hypoperfusion persisted in the left posterior cortex thereafter. Another episode with transient left hemiplegia appeared 7 months later, followed by recurrence of migraine attacks. Analysis of the CACNA1A gene revealed a mutation of c.1997 C>T (p.T666M). None of his family members had migraine. This case represents an unusual evolution of sporadic hemiplegic migraine with manifestations of acute encephalopathy, for which the role of migraine-related inflammatory process is assumed.

Late cytotoxic edema in 2 children with hemiplegia: hemiplegic migraine or stroke?

Hemiplegic migraine (HM) is a rare variant of migraine with aura, characterized by migrainous headache and fully reversible motor deficit within 24 hours. Both sporadic and familial forms of HMs are genetically heterogenous with little information on neuroimaging during and after acute attacks. We report 2 cases of children with presumed HM and late cytotoxic edema.

Multimodal neuroimaging in a child with sporadic hemiplegic migraine: A contribution to understanding pathogenesis

Background: Hemiplegic migraine (HM) is a rare variety of migraine with aura, characterized by motor deficits during the aura, often beginning in childhood. The hemiplegic attacks can be severe and prolonged but the prognosis is usually good. Data on neuroimaging, including diffusion-weighted imaging (DWI) and spectroscopy, during prolonged attacks of HM are quite limited, particularly in children.

Case: An eight-year-old female had a prolonged attack of sporadic HM characterized by right-sided hemiplegia, global aphasia, fever and impairment of consciousness. MRI nine hours after hemiplegia onset was negative, while the following MRI scans (days 4 and 11) documented a progressive increase in cortical swelling in the left hemisphere with mild hyperintensity on DWI and mild reduction of apparent diffusion coefficient values. Proton MRI spectroscopy (MRS) (day 15) showed a decrease in the N-acetylaspartate/creatine ratio in the left hemisphere. 99mTc-ECD single-photon emission tomography (SPET) (day 27) showed marked left hemispheric hypoperfusion. The patient recovered completely after 40 days and neuroimaging follow-up (MRI and SPET) after six months was normal. The patient carried a missense mutation of the ATP1A2 gene.

Conclusion: Multimodal neuroimaging (MRI, DWI, MRS, SPET) in a prolonged HM attack supports evidence for a primary neuronal dysfunction.

Confusional migraine is an adult as well as a childhood disease

Background: Acute confusional migraine (ACM) is considered a rare migraine variant primarily seen in children and adolescents.

Patients and Methods: We present a series of eight adults and two adolescents suffering from migraine attacks associated with transient confusional states.

Results: Eight patients reported two or more such attacks. One of them reported mild head trauma in the past. One patient reported mild head trauma as a possible trigger. Further investigations were unremarkable in all patients and did not suggest underlying structural abnormalities, epilepsy or cerebrovascular disease. In none of these patients did we find another cause to explain the observed phenomenon.

Conclusions: Based on this series of patients, we suggest expanding the concept of confusional migraine from the paediatric population to adults. The temporal course of the confusion as well as the association with visual and other aura symptoms suggest cortical spreading depression as the underlying pathophysiology.