ATP1A2-related epileptic encephalopathy and movement disorder: Clinical features of three novel patients.

OBJECTIVE: Variants in the ATP1A2 gene exhibit a wide clinical spectrum, ranging from familial hemiplegic migraine to childhood epilepsies and early infantile developmental epileptic encephalopathy (EIDEE) with movement disorders. This study aims to describe the epileptology of three unpublished cases and summarize epilepsy features of the other 17 published cases with ATP1A2 variants and EIDEE. METHODS: Medical records of three novel patients with pathogenic ATP1A2 variants were retrospectively reviewed. Additionally, the PUBMED, EMBASE, and Cochrane databases were searched until December 2023 for articles on EIDEE with ATP1A2 variants, without language or publication year restrictions. RESULTS: Three female patients, aged 6 months-10 years, were investigated. Epilepsy onset occurred between 5 days and 2 years, accompanied by severe developmental delay, intellectual disability, drug-resistant epilepsy, severe movement disorder, and recurrent status epilepticus. All individuals had pathogenic variants of the ATP1A2 gene (ATP1A2 c.720_721del (p.Ile240MetfsTer9), ATP1A2c.3022C > T (p.Arg1008Trp), ATP1A2 c.1096G > T (p.Gly366Cys), according to ACMG criteria. Memantine was p) rescribed to three patients, one with a reduction in ictal frequency, one with improvement in gait pattern, coordination, and attention span, and another one in alertness without significant side effects. SIGNIFICANCE: This study reinforces the association between ATP1A2 variants and a severe phenotype. All patients had de novo variants, focal motor seizures with impaired awareness as the primary type of seizure; of the 11 EEGs recorded, 10 presented a slow background rhythm, 7 multifocal interictal epileptiform discharges (IED), predominantly temporal IEDs, followed by frontal IED, as well as ten ictal recordings, which showed ictal onset from the same regions mentioned above. Treatment with antiseizure medication was generally ineffective, but memantine showed moderate improvement. Prospective studies are needed to enlarge the phenotype and assess the efficacy of NMDA receptor antagonist therapies in reducing seizure frequency and improving quality of life.

Movement Disorder Perspectives on Monocarboxylate 8 Deficiency: A Case Series of 3 Colombian Patients with Allan-Herndon-Dudley Syndrome.

BACKGROUND: Deficiencies in the thyroid hormone transporter monocarboxylate 8 (MCT8) due to pathogenic variants in the SLC16A2 gene (OMIM 300095) result in a complex phenotype with main endocrine and neurologic symptoms. This rare disorder, named Allan-Herndon-Dudley syndrome (AHDS) (OMIM 300523), is inherited in an X-linked trait. One of the prominent features of AHDS is the presence of movement disorders (MD), which are complex and carry a significant burden of the disease. CASES: Patient 1: male with hypotonia since birth, developmental delay, dystonic posturing at 4 months and at 15 months, and startle reaction developed with sensory stimuli. Patient 2: male, at 2 months, shows hypotonia and developmental delay, paroxysmal episodes triggered by a stimulus with sudden blush, tonic asymmetric posture, and no epileptiform activity. At 10 months, generalized dystonic posturing. Patient 3: typical neurodevelopmental milestones until 6 months; at 24 months, dystonia, startle reaction, and upper motoneuron signs. CONCLUSIONS: We aim to describe our patients diagnosed with AHDS, focusing on MD phenomenology and strengthening the phenotype-genotype correlations for this rare condition.

DRPLA: An unusual disease or an underestimated cause of ataxia in Brazil?

BACKGROUND: Dentatorubral-pallidoluysian atrophy (DRPLA) is a rare autosomal dominant spinocerebellar ataxia caused by pathological expansion of CAG trinucleotide repeats in the ATN1 gene. Most cases were described in patients from Japanese ancestry who presented with adult-onset progressive cerebellar ataxia associated with cognitive impairment, choreoathetosis and other movement disorders. DRPLA has been rarely described in Brazilian patients. METHODS: We performed a retrospective observational multicentric study including six different Neurology Centers in Brazil. All patients with genetically confirmed diagnosis of DRPLA had their medical records evaluated and clinical, genetic and neuroimaging features were analyzed. RESULTS: We describe of eight Brazilian patients (5 male, 3 female) from four nuclear families with genetically confirmed DRPLA. The most common neurological features included cerebellar ataxia (n = 7), dementia (n = 3), chorea (n = 2), psychiatric disturbances (n = 2), progressive myoclonic epilepsy (n = 2) and severe bulbar signs (n = 1). Progressive myoclonic epilepsy was observed in two juvenile-onset cases before 20-year. A large CAG trinucleotide length was observed in the two juvenile-onset cases and genetic anticipation was observed in all cases. Neuroimaging studies disclosed cerebellar atrophy (n = 6), as well as brainstem and cerebellar atrophy (n = 2) and leukoencephalopathy (n = 1). CONCLUSION: The patients described herein reinforce that clinical features of DRPLA are highly influenced by age of onset, genetic anticipation and CAG repetition lengths. There is a large complex spectrum of neurological features associated with DRPLA, varying from pure cerebellar ataxia to dementia associated with other movement disorders (myoclonus, choreoathetosis). DRPLA is an unusual cause of cerebellar ataxia and neurodegeneration in Brazilian patients.

Worldwide barriers to genetic testing for movement disorders.

BACKGROUND AND PURPOSE: Despite enormous advances in identifying genetic variants responsible for many neurological diseases, access to genetic testing may be limited in clinical practice. The objective of this study was to assess worldwide access to genetic tests for movement disorders and factors impacting their utilization. METHODS: The Rare Movement Disorders Study Group of the International Parkinson and Movement Disorder Society designed an online survey electronically mailed to all 7815 members. RESULTS: Survey data completed by 1269 participants from 109 countries were analysed. Limited access to geneticists and genetic counsellors was reported in many world regions compared to Europe and North America. Availability of genetic testing was limited, with rates of access lower than 50%. Genetic testing for chorea was the most commonly available. For parkinsonism, dystonia, ataxia, hereditary spastic paraplegias and metabolic disorders, there was limited access to genetic testing in all countries compared to Europe and North America, with significant differences found for Africa, Central/South America, Asia. In many regions, genetic testing was supported by either private or public funding. Genetic testing was free of charge in Europe according to 63.5% of respondents. In North America, Africa, Central/South America, Asia and the Middle East access to free of charge genetic testing was by far significantly lower compared to Europe. CONCLUSIONS: This survey highlights difficulties in accessing genetic testing and individuals with expertise in genetics at the worldwide level. In addition, major disparities in genetic testing amongst world regions are highlighted, probably due to a variety of factors including financial barriers.

Review of Hereditary and Acquired Rare Choreas.

Background: Movement disorders are often a prominent part of the phenotype of many neurologic rare diseases. In order to promote awareness and diagnosis of these rare diseases, the International Parkinson's and Movement Disorders Society Rare Movement Disorders Study Group provides updates on rare movement disorders. Methods: In this narrative review, we discuss the differential diagnosis of the rare disorders that can cause chorea. Results: Although the most common causes of chorea are hereditary, it is critical to identify acquired or symptomatic choreas since these are potentially treatable conditions. Disorders of metabolism and mitochondrial cytopathies can also be associated with chorea. Discussion: The present review discusses clues to the diagnosis of chorea of various etiologies. Authors propose algorithms to help the clinician in the diagnosis of these rare disorders.

Movement disorders in spinocerebellar ataxias in a cohort of Brazilian patients.

BACKGROUND: Movement disorders (MDs) are well recognized in all subtypes of spinocerebellar ataxias (SCA), but phenomenology and frequency vary widely. METHODS: Three hundred seventy-eight patients, from 169 Brazilian families, with SCAs were assessed with neurological examination and molecular genetic testing. RESULTS: Dystonia was the most common movement disorder, found in 5.5% of all patients, particularly in SCA3. We observed Parkinsonian features in 6.6% of SCA3 patients, and myoclonus in two patients of our cohort. CONCLUSIONS: Our study demonstrated that MDs are major extracerebellar manifestations of SCA. The observed phenotypes in addition to ataxia may provide significant clues for a particular SCA genotype.

Evidence of a progressive motor dysfunction in Mucopolysaccharidosis type I mice.

Mucopolysaccharidosis (MPS) type I (Hurler syndrome) is a lysosomal storage disorder characterized by deficiency of alpha-L-iduronidase (IDUA), intracellular storage of glycosaminoglycans (GAGs) and progressive neurological pathology. The MPS I mouse model provides an opportunity to study the pathophysiology of this disorder and to determine the efficacy of novel therapies. Previous work has demonstrated a series of abnormalities in MPS I mice behavior, but so far some important brain functions have not been addressed. Therefore, in the present study we aimed to determine if MPS I mice have motor abnormalities, and at what age they become detectable. MPS I and normal male mice from 2 to 8 months of age were tested in open-field for locomotor activity, hindlimb gait analysis and hang wire performance. We were able to detect a progressive reduction in the crossings and rearings in the open field test and in the hang wire test in MPS I mice from 4 months, as well as a reduction in the gait length at 8 months. Histological examination of 8-month old mice cortex and cerebellum revealed storage of GAGs in Purkinje cells and neuroinflammation, evidenced by GFAP immunostaining. However TUNEL staining was negative, suggesting that death does not occur. Our findings suggest that MPS I mice have a progressive motor dysfunction, which is not caused by loss of neuron cells but might be related to a neuroinflammatory process.

Restorative effect of intracerebroventricular insulin-like growth factor-I gene therapy on motor performance in aging rats.

Insulin-like growth factor-I (IGF-I) is a powerful neuroprotective molecule in the brain and spinal cord. We have previously shown that intracerebroventricular (i.c.v.) IGF-I gene therapy is an effective strategy to increase IGF-I levels in the cerebrospinal fluid (CSF). Since aging in rats is associated with severe motor function deterioration, we implemented i.c.v. IGF-I gene therapy in very old rats (30-31 months) and assessed the beneficial impact on motor performance. We used recombinant adenovectors (RAds) expressing either green fluorescent protein (GFP) or rat IGF-I. Injection in the lateral or fourth ventricle led to high transgene expression in the ependymal cell layer in the brain and cervical spinal cord. RAd-IGF-I-injected rats but not RAd-GFP-injected controls, showed significantly increased levels of CSF IGF-I. Motor tests showed the expected age-related decline in aged rats. Seventeen-day IGF-I gene therapy induced a significant improvement in motor performance in the aged but not in the young animals. These results show that IGF-I is an effective restorative molecule in the aging brain and spinal cord. The data also reveal that the ependymal route constitutes a promising approach for implementing protective IGF-I gene therapy in the aging CNS.

Nigral neurodegeneration triggered by striatal AdIL-1 administration can be exacerbated by systemic IL-1 expression.

Neuroinflammation has been proposed as an important component of Parkinson's Disease (PD) aetiology and/or progression. However, the inflammatory components and the mechanisms underlying their effects are only partially known. By injecting an adenovirus expressing IL-1 in the striatum, we provoked progressive neurodegeneration of dopaminergic cells in the substantia nigra, motor symptoms and microglial activation. All these effects were attenuated by an anti-inflammatory treatment. Interestingly, peripheral inflammatory stimuli exacerbated IL-1beta induced neurodegeneration and the central inflammatory reaction. These data provide evidence that central, chronic IL-1beta expression can trigger and systemic IL-1beta exacerbate nigral neurodegeneration and highlight the functional relevance of this cytokine in PD.

Progressive neurodegeneration and motor disabilities induced by chronic expression of IL-1beta in the substantia nigra.

The functional role of the long-lasting inflammation found in the substantia nigra (SN) of Parkinson's disease (PD) patients and animal models is unclear. Proinflammatory cytokines such as interleukin-1beta (IL-1beta) could be involved in mediating neuronal demise. However, it is unknown whether the chronic expression of cytokines such as IL-1beta in the SN can alter neuronal vitality. The aim of this study was to investigate the effects of the chronic expression of IL-1beta in the adult rat SN using a recombinant adenovirus expressing IL-1beta. The chronic expression of IL-1beta for 60 days induced dopaminergic cell death in the SN and unilateral akinesia starting only at 21 days post-injection. Microglial cell activation and inflammatory cell infiltrate were associated with dopaminergic cell death and motor disabilities. Astrocytic activation was delayed and associated with scar formation. The chronic expression of a single proinflammatory cytokine as IL-1beta in the SN elicited most of the characteristics of PD, including progressive dopaminergic cell death, akinesia and glial activation. Our data suggest that IL-1beta per se is able to mediate inflammatory-mediated toxic effects in the SN if its expression is sustained. This model will be helpful to identify possible therapeutic targets related to inflammation-derived neurodegeneration in the SN.

[Perisylvian syndrome: report of one Brazilian family with focus on the genetic mode of inheritance and clinical spectrum]. / Síndrome peri-sylviana: estudo de uma família brasileira com ênfase na modalidade de transmissão genética e espectro clínico.

Perisylvian syndrome (PS) refers to a variety of clinical manifestations associated with lesions in the perisylvian or opercular region. Acquired lesions such as cerebrovascular diseases or virus encephalitis and congenital lesions such as polymicrogyria (PMG) may be implied as etiological factors. The onset of the PS may occur in early childhood. The aim of this study was to report one family with PS in order to draw attention to this rarely diagnosed entity. Our family has five affected patients, three children and two male adults. All of them had developmental language disorder. Epilepsy, motor deficit and pseudobulbar signs (such as drooling) were detected in one child who had diffuse PMG along the Sylvian fissure. Subtle clinical manifestations correlated with either subtle MRI findings or normal MRI. Most reported families provide evidence suggestive of X-linked transmission. However, the most likely mode of inheritance in our family is autosomal dominant, since a male to male transmission was documented.

Characterization of the spontaneous and gripping-induced immobility episodes on taiep rats.

In 1989, we described a new autosomic-recessive myelin-mutant rat that develops a progressive motor syndrome characterized by tremor, ataxia, immobility episodes (IEs), epilepsy, and paralysis. taiep is the acronym of these symptoms. The rat developed a hypomyelination, followed by demyelination. At an age of 7-8 months, taiep rats developed IEs, characterized electroencephalographically by REM sleep-like cortical activity. In our study, we analyzed the ontogeny of gripping-induced IEs between 5 and 18 months, their dependence to light-dark changes, sexual dimorphism, and susceptibility to mild stress. Our results showed that IEs start at an age of 6.5 months, with a peak frequency between 8.5 and 9.5 months. IEs have two peaks, one in the morning (0800-1000 h) and a second peak in the middle of the night (2300-0100 h). Spontaneous IEs showed an even distribution with a mean of 3 IEs every 2 h. IEs are sexually dimorphic being more common in male rats. The IEs can be induced by gripping the rat by the tail or the thorax, but most of the IEs were produced by gripping the tail. Mild stress produced by i.p. injection of physiological saline significantly decreased IEs. These results suggested that IEs are dependent on several biological variables, which are caused by hypomyelination, followed by demyelization, which causes alterations in the brainstem and hypothalamic mechanisms responsible for the sleep-wake cycle regulation, producing emergence of REM sleep-like behavior during awake periods.

Síndrome peri-sylviana: estudo de uma família brasileira com ênfase na modalidade de transmissão genética e espectro clínico / Perisylvian syndrome: report of one Brazilian family with focus on the genetic mode of inheritance and clinical spectrum

Síndrome peri-sylviana (SP) refere-se a diversas manifestações clínicas que podem acompanhar lesões que comprometem a região peri-sylviana ou opercular, podendo ser adquirida, como em acidentes vasculares cerebrais ou encefalites virais, ou ser congênita. A SP congênita pode se manifestar com grande variação clínica e em idades precoces. Com o advento da ressonância magnética (RM) foi possível observar a presença de polimicrogiria (PMG) na região da fissura de Sylvius em diversos pacientes com quadro clínico de SP. O objetivo do presente estudo é analisar e divulgar essa entidade raramente diagnosticada por meio da descrição de uma família. A família em questão compõe-se de cinco indivíduos acometidos, sendo o distúrbio de linguagem a manifestação mais prevalente, ou seja, presente em todos eles. Epilepsia, déficit motor e sinais pseudobulbares (como sialorréia) foram evidenciados no paciente que mostrou maior alteração à RM (PMG difusa). A paciente com PMG parietal posterior e os outros três com RM normais tiveram manifestações clínicas mais sutis. Apesar da maioria das famílias descritas até o momento apresentar transmissão ligada ao cromossomo X, a nossa família sugere transmissão autossômica dominante, já que dois meninos afetados são filhos de homens também acometidos. Os nossos dados reforçam a idéia de que a SP apresenta heterogeneidade genética.

[Channelopathies in neurology]. / Canalopatías en neurología.

INTRODUCTION: The main function of ionic channels are the conduction, recognition and selection of specific ions. They open and close in respond answer to electrical, mechanical and chemical stimulus, acting in the excitation or transmission of diverse tissues. DEVELOPMENT: The clinical and molecular manifestations of channelophathies are varied and use to shown up in continuous or paroxystic ways. Alteration of Ca channels cause muscle dysfunction periodic paralysis with or without potassium changes, myasthenia or myasthenic disorders, like Lambert Eaton syndrome, amyotrophic lateral sclerosis, Central Core disease, malignant hyperthermia. Cl and Na channels alterations produce myotonic diseases: Thomsen, Becker and paramyothonies, potassium sensible paralysis, fluctuant congenital myotonic, Andersen s syndrome. Channelopathies also produce various episodic ataxia type 1, type 2, spinocerebellar 6 and familial hemiplegic migraine. Abnormal paroxystic movements are present as channelophaties: episodic nocturnal dystonia, paroxystic dyskinesia. In some families are associates abnormal episodic movements and epilepsy. Several epileptic syndromes are also related with channels dysfunction: frontal lobe nocturnal epilepsy, choreoatetosis epilepsy, benign neonatal convulsions, generalized epilepsy with febrile convulsions plus. CONCLUSIONS: Voltage gated channels dysfunction are related to diseases with episodic phenomena or permanent conditions on muscle or neuronal tissues, with clinical and genetic heterogenous manifestations.

Correlation of cognitive, neurologic, and ovarian outcome with the Q188R mutation of the galactose-1-phosphate uridyltransferase gene.

This study was conducted to determine whether there is a genotype/phenotype correlation between aspects of cognitive, neurologic, and ovarian outcome in patients with galactosemia and the Q188R mutation of the galactose-1-phosphate uridyltransferase gene. The results showed that the Q188R mutation was found in 72% of alleles: 38 patients were homozygous and 21 were heterozygous for Q188R; eight patients did not have the mutation. The mean Broad Cognitive score for the group homozygous for Q188R was 75 (SD = 16), which was not statistically different from the outcome for the heterozygous group (mean score, 67; SD = 25) or the negative group (mean score, 88; SD = 21). Tremor, ataxia, and dysmetria were found in 12 subjects, and there was no association with Q188R status. Similarly, there was no association of this mutation with the development of primary amenorrhea (8 subjects) versus secondary amenorrhea (found in 14 women). Our findings suggests that the variability of outcome for patients with classic galactosemia cannot be explained by Q188R status alone, at least with regard to cognitive functioning, presence of neurologic symptoms, and timing of the onset of ovarian failure.

Familial hemifacial spasm.

Two brothers developed hemifacial spasm at 63 and 70 years of age. Spasms occurred on the left and right sides of the face, respectively. Computed tomography scan and magnetic resonance imaging failed to show any abnormality. In addition, a third sibling reported a history of a peripheral facial palsy, which remitted spontaneously without sequelae. This is the fourth description of familial hemifacial spasms. This family is unique in that hemifacial spasm presented on different sides in the two brothers, and involvement was limited to one generation. Age at onset was later than for other familial cases and similar to sporadic cases.