Guillain-Barré syndrome during SARS-CoV-2 pandemic: A case report and review of recent literature.

Acute demyelinating inflammatory polyneuropathy (AIDP) is the most common type of Guillain-Barré syndrome (GBS) in Europe, following several viral and bacterial infections. Data on AIDP-patients associated with SARS-CoV-2 (coronavirus-2) infection are scarce. We describe the case of a 54-years-old Caucasian female patient with typical clinical and electrophysiological manifestations of AIDP, who was reported positive with PCR for SARS-CoV-2, 3 weeks prior to onset of the neurological symptoms. She did not experience a preceding fever or respiratory symptoms, but a transient loss of smell and taste. At the admission to our neurological department, a progressive proximally pronounced paraparesis, areflexia, and sensory loss with tingling of all extremities were found, which began 10 days before. The modified Erasmus Giullain-Barré Syndrome outcome score (mEGOS) was 3/9 at admission and 1/12 at day 7 of hospitalization. The electrophysiological assessment proved a segmental demyelinating polyneuropathy and cerebrospinal fluid examination showed an albuminocytologic dissociation. The neurological symptoms improved significantly during treatment with immunoglobulins. Our case draws attention to the occurrence of GBS also in patients with COVID-19 (coronavirus disease 2019), who did not experience respiratory or general symptoms. It emphasizes that SARS-CoV-2 induces immunological processes, regardless from the lack of prodromic symptoms. However, it is likely that there is a connection between the severity of the respiratory syndrome and further neurological consequences.

The coexistence of dynamin 2 mutation and multiple mitochondrial DNA (mtDNA) deletions in the background of severe cardiomyopathy and centronuclear myopathy.

Dynamin2 (DNM2) gene mutations may result in Charcot-Marie-Tooth disease and centronuclear myopathy. Here, we present a patient suffering from cardiomyopathy and centronuclear myopathy with repetitive discharges and mild axonal neuropathy due to DNM2 mutation. Detailed cardiological and neurological examinations, electrophysiological tests, muscle biopsy, and molecular genetic analysis were performed. The patient developed left bundle branch block at age 40 and was fitted with a pacemaker at the age of 43. The patient has severe heart failure, ptosis, strabism, facial and proximal muscle weakness. Electrophysiological investigations found myopathy, complex repetitive discharges, and axonal neuropathy. Skeletal muscle biopsy detected centronuclear myopathy and cytochrome C oxidase (COX) negative fibers. Genetic analysis detected a pathogenic c.1105C>T (p.R369W) DNM2 gene mutation and heteroplasmic multiple mitochondrial DNA (mtDNA) deletion. Our data broadens the phenotypic spectrum of DNM2 mutations. The presence of the multiple mtDNA deletions may provide new aspects to understanding the pathogenesis of multisystemic symptoms in patients with DNM2 mutations.

The modifying effect a PMP22 deletion in a family with Charcot-Marie-Tooth type 1 neuropathy due to an EGR2 mutation.

BACKGROUND: Mutations of both the PMP22 and EGR2 genes cause Charcot-Marie-Tooth (CMT) disease type 1. Deletion of the PMP22 gene, results in hereditary neuropathy with liability to pressure palsies. More publications exist about the interaction of PMP22 duplication and other CMT-causing gene mutations. In these cases the intrafamiliar discordant phenotypes draw the attention to the possible role of modifying genes. The gene-gene interactions between the PMP22 and EGR2 genes are not well understood. CASE REPORT: We report two brothers with late onset CMT1 due to a c. 1142 G>A (Arg381His) heterozygous substitution in the EGR2 gene. Additionally, the older brother with the less severe symptoms harbored the PMP22 gene deletion also. CONCLUSION: The coexistence of the two genetic alterations did not aggravate the clinical symptoms. Moreover, the PMP22 deletion appeared to have a beneficial modifying effect, thus implying potential gene-gene interaction of PMP22 and EGR2. PMP22 deletion may increase Schwann cells proliferation and compensate the dominant-negative effect of the Arg381 His substitution in the EGR2 gene.

The role of SCARB2 as susceptibility factor in Parkinson's disease.

BACKGROUND: Genetic variation in the glucocerebrosidase (GBA) gene is strongly associated with Parkinson's disease (PD). Transport of glucocerebrosidase to the lysosome involves the protein encoded by the SCARB2 gene. An association between the common SNP rs6812193, upstream of SCARB2, and PD has been reported previously. The role of exonic variants in the SCARB2 gene in PD has not been examined. METHODS: We studied the role of exonic variants in SCARB2 and tried to replicate the association between the SNP rs6812193 and PD in a German and Austrian sample. Screening of all SCARB2 exons by high-resolution melting curve analysis was performed in 376 German PD patients. The SNP rs6812193 was analyzed in 984 PD patients and 1014 general population controls. RESULTS: We identified no novel exonic variants in SCARB2 but confirmed the association between SNP rs6812193 and PD (OR, 0.86; P=.02).

Variants in eukaryotic translation initiation factor 4G1 in sporadic Parkinson's disease.

Recently, mutations in eukaryotic translation initiation factor 4G1 (EIF4G1) were reported as a rare cause of familial Parkinson's disease (PD). We screened the 33 exons of EIF4G1 by high-resolution melting curve analysis for variants in our Central European cohort of 376 PD cases. Variant frequency was assessed in a total of 975 PD cases and 1,014 general population controls. Eight novel nonsynonymous and four synonymous variants were identified. In our cohort, novel and previously identified nonsynonymous variants were very rare. Although it is possible that our general population controls also comprise individuals who have or could develop PD in the future, the presence of the original mutation (EIF4G1 p.Arg1205 His) in three controls only, raises questions about the causality of this variant with regard to PD.

Psychiatric symptoms of patients with primary mitochondrial DNA disorders.

BACKGROUND: The aim of our study was to assess psychiatric symptoms in patients with genetically proven primary mutation of the mitochondrial DNA. METHODS: 19 adults with known mitochondrial mutation (MT) have been assessed with the Stanford Health Assessment Questionnaire 20-item Disability Index (HAQ-DI), the Symptom Check List-90-Revised (SCL-90-R), the Beck Depression Inventory-Short Form (BDI-SF), the Hamilton Depression Rating Scale (HDRS) and the clinical version of the Structured Clinical Interview for the the DSM-IV (SCID-I and SCID-II) As control, 10 patients with hereditary sensorimotor neuropathy (HN), harboring the peripheral myelin protein-22 (PMP22) mutation were examined with the same tools. RESULTS: The two groups did not differ significantly in gender, age or education. Mean HAQ-DI score was 0.82 in the MT (range: 0-1.625) and 0.71 in the HN group (range: 0-1.625). Level of disability between the two groups did not differ significantly (p = 0.6076). MT patients scored significantly higher on the BDI-SF and HDRS than HN patients (12.85 versus 4.40, p = 0.031, and 15.62 vs 7.30, p = 0.043, respectively). The Global Severity Index (GSI) of SCL-90-R also showed significant difference (1.44 vs 0.46, p = 0.013) as well as the subscales except for somatization. SCID-I interview yielded a variety of mood disorders in both groups. Eight MT patient (42%) had past, 6 (31%) had current, 5 (26%) had both past and current psychiatric diagnosis, yielding a lifetime prevalence of 9/19 (47%) in the MT group. In the HN group, 3 patients had both past and current diagnosis showing a lifetime prevalence of 3/10 (30%) in this group. SCID-II detected personality disorder in 8 MT cases (42%), yielding 3 avoidant, 2 obsessive-compulsive and 3 personality disorder not otherwise specified (NOS) diagnosis. No personality disorder was identified in the HN group. CONCLUSIONS: Clinicians should be aware of the high prevalence of psychiatric symptoms in patients with mitochondrial mutation which has both etiologic and therapeutic relevance.

[The absence of the common LRRK2 G2019S mutation in 120 young onset Hungarian Parkinon's disease patients]. / Az LRRK2 gyakori G2019s-mutációjának hiánya 120, korai kezdetu magyar Parkinson-beteg esetében.

Parkinson's disease is a promising target of applying personalized medicine. For this purpose it is crucial to reveal the genetic and environmental factors, which contribute to the disease, also to collect epidemiologic data and to preserve the patients samples and data in a proper biobank. In our investigation we examined the prevalence of the most frequent Parkinson's disease causing LRRK2 G2019S mutation in a Hungarian Parkinson-patient group. From 120 patients, we haven't detected this substitution in anyone. Our investigation suggest that the mutation LRRK2 G2019S may be a rare cause of Parkinson disease in the Hungarian population.

[Therapy for anti-MuSK antibody positive myasthenia gravis]. / A MuSK-ellenes antitest pozitív myasthenia gravis kezelése.

The authors report the case of a 27-year-old woman with muscle-specific receptor tyrosine kinase antibody positive myasthenia with predominantly ocular and bulbar symptoms. Both edrophonium and low dose (4×30 mg/day) pyridostigmin resulted in cholinergic side effects including fasciculation mainly in the facial and neck muscles, and excessive salivation. The patient responded well to a relatively high dose of chronic corticosteroid treatment (methyprednisolone 64mg/day), but the decrease of the corticosteroid dose below 16 mg/day induced exacerbation of the clinical symptoms. Immunosuppression with azathioprine and methotrexate failed to maintain the clinical improvement. However, plasma exchange was always very effective, and all clinical symptoms improved significantly. The authors conclude that patients with muscle-specific receptor tyrosine kinase antibody positive myasthenia gravis should have an individual treatment protocol differing from those used in patients who do not have this antibody but are positive for acetylcholine-receptor antibody. Identification of the pathogenic antibody in the early stage of myasthenia gravis may help to develop the optimal, individualized treatment strategy, to avoid severe side effects, and to achieve fast improvement.

[Clinical manifestations, course and outcome of enzyme replacement therapy in Hungarian patients with Pompe's disease]. / Pompe-kór fenotípusvariációi, kórlefolyása és az enzimpótló kezelés eredményei: hazai tapasztalatok.

UNLABELLED: Pompe's disease is an autosomal recessive disease caused by deficiency of acid-alpha-glucosidase. AIMS AND METHODS: Authors analyzed the phenotype of 11 Hungarian patients with Pompe's disease and evaluated clinical parameters and response to enzyme replacement therapy during a long-term follow-up in 8 patients. RESULTS: One patient with atypical infantile form presented with cardiomyopathy and a very slow progression of motor deficits; after 2 years of enzyme replacement therapy no disability was present at the age 6 years. Another patient was asymptomatic at the age of 2.5 years. The adult onset form was characterized by slight to prominent limb-girdle myopathy with an age of onset between 20 and 50 years. In 3 of such cases respiratory insufficiency was also present. CONCLUSIONS: Hungarian patients with Pompe's disease presented with a wide phenotypic variability ranging from atypical early childhood form with slowly progressive course to late-onset limb-girdle myopathy with variable courses. Enzyme replacement therapy resulted in significant improvement in motor and respiratory functions in most of the patients.

[Genetics and present therapy options in Parkinson's disease: a review]. / A Parkinson-kór genetikája és aktuális terápiás lehetoségei.

In the past years, six monogenic forms of Parkinson disease have clearly been associated with this movement disorder. The most frequent forms are LRRK2- and Parkin-associated Parkinson disease. Currently, a genetic diagnosis does not change the therapy, the genes involved in genetic Parkinson disease help to understand the underlying pathophysiologic mechanisms of Parkinson disease. Beside the overview of the molecular-genetic basis, we give a review about genetic testing, pharmacological and other multidisciplinary treatment options.

The rs13388259 Intergenic Polymorphism in the Genomic Context of the BCYRN1 Gene Is Associated with Parkinson's Disease in the Hungarian Population.

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by bradykinesia, resting tremor, and muscle rigidity. To date, approximately 50 genes have been implicated in PD pathogenesis, including both Mendelian genes with rare mutations and low-penetrance genes with common polymorphisms. Previous studies of low-penetrance genes focused on protein-coding genes, and less attention was given to long noncoding RNAs (lncRNAs). In this study, we aimed to investigate the susceptibility roles of lncRNA gene polymorphisms in the development of PD. Therefore, polymorphisms (n=15) of the PINK1-AS, UCHL1-AS, BCYRN1, SOX2-OT, ANRIL and HAR1A lncRNAs genes were genotyped in Hungarian PD patients (n=160) and age- and sex-matched controls (n=167). The rare allele of the rs13388259 intergenic polymorphism, located downstream of the BCYRN1 gene, was significantly more frequent among PD patients than control individuals (OR = 2.31; p=0.0015). In silico prediction suggested that this polymorphism is located in a noncoding region close to the binding site of the transcription factor HNF4A, which is a central regulatory hub gene that has been shown to be upregulated in the peripheral blood of PD patients. The rs13388259 polymorphism may interfere with the binding affinity of transcription factor HNF4A, potentially resulting in abnormal expression of target genes, such as BCYRN1.

[DYT1 positive generalised dystonia: a case study of two siblings]. / DYT1-pozitív generalizált dystonia: egy testvérpár esettanulmánya.

The early-onset generalised dystonia is a dyskinetic movement disorder with a wide variety in phenotype and poor response to pharmacological treatment. A mutation on the DYT1 gene is responsible for the disease in more than 50% of cases with typical early-onset dystonia beginning in a limb. We describe the medical history of two brothers with first signs of focal dystonia at age 12 starting with right side lower limb dystonia of the older brother and writers cramp of the younger one. In both over a period of 6 and 10 years dystonia generalised. The negative results of MRI, electrophysiological testing and muscle biopsy corroborate the diagnosis of primary dystonia. The DNA from the older patient was tested for the 3 bp deletion in exon 5 of the DYT1 gene by restriction enzyme. The positive result confirmed the diagnosis of early-onset primary dystonia. A short synopsis of routine molecular genetic tests indications and treatment options is outlined.

Three novel mutations and genetic epidemiology analysis of the Gap Junction Beta 1 (GJB1) gene among Hungarian Charcot-Marie-Tooth disease patients.

Pathogenic variants of the gap junction beta 1 (GJB1) gene are responsible for the Charcot-Marie-Tooth neuropathy X type 1 (CMTX1). In this study, we report the mutation frequency of GJB1 in 210 Hungarian CMT patients and the phenotype comparison between male and female CMTX1 patients. Altogether, 13 missense substitutions were found in the GJB1 gene. Among them, 10 have been previously described as pathogenic variants (p.Arg15Trp, p.Val63Ile, p.Leu89Val, p.Ala96Gly, p.Arg107Trp, p.Arg142Gln, p.Arg164Trp, p.Arg164Gln, p.Pro172Ala and p.Asn205Ser), while 3 were novel, likely pathogenic alterations (p.Val13Glu, p.Glu186Gly, p.Met194Ile). These variants were not present in controls and were predicted as disease causing by in silico analysis. The frequency of the variants was 6.7% in our cohort which refers to a common cause of hereditary neuropathy among Hungarian patients. In addition to the classical phenotype, CNS involvement was proved in 26.1% of the CMTX1 patients. GJB1 pathogenic alterations were found mainly in males but we also detected them in female probands. The statistical analysis of CMTX1 patients revealed a significant difference between the two genders regarding the age of onset, Charcot-Marie-Tooth neuropathy and examination scores.

Rare variants in ß-Amyloid precursor protein (APP) and Parkinson's disease.

Many individuals with Parkinson's disease (PD) develop cognitive deficits, and a phenotypic and molecular overlap between neurodegenerative diseases exists. We investigated the contribution of rare variants in seven genes of known relevance to dementias (ß-amyloid precursor protein (APP), PSEN1/2, MAPT (microtubule-associated protein tau), fused in sarcoma (FUS), granulin (GRN) and TAR DNA-binding protein 43 (TDP-43)) to PD and PD plus dementia (PD+D) in a discovery sample of 376 individuals with PD and followed by the genotyping of 25 out of the 27 identified variants with a minor allele frequency <5% in 975 individuals with PD, 93 cases with Lewy body disease on neuropathological examination, 613 individuals with Alzheimer's disease (AD), 182 cases with frontotemporal dementia and 1014 general population controls. Variants identified in APP were functionally followed up by Aß mass spectrometry in transiently transfected HEK293 cells. PD+D cases harbored more rare variants across all the seven genes than PD individuals without dementia, and rare variants in APP were more common in PD cases overall than in either the AD cases or controls. When additional controls from publically available databases were added, one rare variant in APP (c.1795G>A(p.(E599K))) was significantly associated with the PD phenotype but was not found in either the PD cases or controls of an independent replication sample. One of the identified rare variants (c.2125G>A (p.(G709S))) shifted the Aß spectrum from Aß40 to Aß39 and Aß37. Although the precise mechanism remains to be elucidated, our data suggest a possible role for APP in modifying the PD phenotype as well as a general contribution of genetic factors to the development of dementia in individuals with PD.

Different patterns of nerve enlargement in polyneuropathy subtypes as detected by ultrasonography.

The purpose of our study was to examine how the pathologic type of polyneuropathy affects nerve size as assessed by high-resolution ultrasonography with a 15 MHz transducer. Cross-sectional area (CSA) of the C5-C7 nerve roots and several upper and lower limb nerves at multiple sites was measured in 38 patients with acquired diffuse sensorimotor demyelinating or axonal polyneuropathy and in 34 healthy control subjects. Significant differences were found among the groups for all nerve and root segments: Both types of polyneuropathy are characterized by nerve enlargement in comparison to controls, but in different patterns. In demyelinating polyneuropathies, an additional degree of nerve thickening appears in proximal upper limb nerves and cervical nerve roots compared with axonal polyneuropathies. With respect to the other nerves, a similar degree of nerve enlargement was observed in both patient groups. These results highlight that ultrasonography may be a complementary tool in differentiating polyneuropathies.

Mitochondrial DNA mutations and cognition: a case-series report.

Mutations in the mitochondrial genome can impair normal metabolic function in the central nervous system (CNS) where cellular energy demand is high. Primary mitochondrial DNA (mtDNA) mutations have been linked to several mitochondrial disorders that have comorbid psychiatric, neurologic, and cognitive sequelae. Here, we present a series of cases with primary mtDNA mutations who were genotyped and evaluated across a common neuropsychological battery. Nineteen patients with mtDNA mutations were genotyped and clinically and cognitively evaluated. Pronounced deficits in nonverbal/visuoperceptual reasoning, verbal recall, semantic word generativity, and processing speed were evident and consistent with a "mitochondrial dementia" that has been posited. However, variation in cognitive performance was noteworthy, suggesting that the phenotypic landscape of cognition linked to primary mtDNA mutations is heterogeneous. Our patients with mtDNA mutations evidenced cognitive deficits quite similar to those commonly seen in Alzheimer's disease and could have clinical relevance to the evaluation of dementia.

Rare variants in PLXNA4 and Parkinson's disease.

Approximately 20% of individuals with Parkinson's disease (PD) report a positive family history. Yet, a large portion of causal and disease-modifying variants is still unknown. We used exome sequencing in two affected individuals from a family with late-onset familial PD followed by frequency assessment in 975 PD cases and 1014 ethnically-matched controls and linkage analysis to identify potentially causal variants. Based on the predicted penetrance and the frequencies, a variant in PLXNA4 proved to be the best candidate and PLXNA4 was screened for additional variants in 862 PD cases and 940 controls, revealing an excess of rare non-synonymous coding variants in PLXNA4 in individuals with PD. Although we cannot conclude that the variant in PLXNA4 is indeed the causative variant, these findings are interesting in the light of a surfacing role of axonal guidance mechanisms in neurodegenerative disorders but, at the same time, highlight the difficulties encountered in the study of rare variants identified by next-generation sequencing in diseases with autosomal dominant or complex patterns of inheritance.

Ultrasonography of MADSAM neuropathy: focal nerve enlargements at sites of existing and resolved conduction blocks.

Using the emerging technique of peripheral nerve ultrasonography, multiple focal nerve swellings corresponding to sites of existing conduction blocks have been described in demyelinating polyneuropathies. We report two cases of multifocal acquired demyelinating sensory and motor neuropathy (MADSAM). In the first, multiple focal nerve enlargements were detected by ultrasound at sites of previous conduction blocks, well after complete clinical and electrophysiological resolution. In the second case, existing proximal conduction blocks could be localized by ultrasound. Our cases highlight the importance of nerve ultrasound in identifying conduction blocks and demonstrate that ultrasonographic morphological changes may outlast functional recovery in demyelinating neuropathies.

Coexisting huntingtin and SCA8 repeat expansion: case report of a severe complex neurodegenerative syndrome.

We report the case of a 29 year old woman with a complex movement disorder syndrome due to the combination of coexisting pathological triplet repeat expansions of huntingtin and ATXN8 genes. The disease course was characterized by mental disturbances including cognitive decline and changes in personality starting at the age of 12 years, followed by twisting motions, intentional tremor and gait ataxia. Later Parkinsonian symptoms of micrographia, bradykinesia, muscle rigidity and mental decline became dominant. Brain MRI showed hypoplasia of the nucleus caudatus and generalized atrophy; MR spectroscopy revealed a decrease of all typical metabolites except for an increased level of lactate and acetate. Therapeutic trials with pramipexole, ropinirole and tetrabenazine showed no benefit, while levetiracetam caused agitation and hallucinations. We discuss phenotype-genotype correlation and the rule of triplet repeat expansions of gene ATXN8.

Chronic high-frequency globus pallidus internus stimulation in different types of dystonia: a clinical, video, and MRI report of six patients presenting with segmental, cervical, and generalized dystonia.

The results of deep brain stimulation (DBS) of the globus pallidus internus (Gpi) in six patients with generalized, focal, and segmental dystonia are presented. Pre- and postoperative assessments are given for one patient with generalized inherited dystonia and for five patients with idiopathic segmental or cervical dystonia. Clinical symptoms were evaluated before and 3-12 months after surgery using the Burke-Fahn-Marsden (BFM) dystonia rating scale for primary torsion dystonia and the Tsui scale for cervical dystonia. The Short-Form Health Survey (SF-36) was completed by each patient to document preoperative and postoperative health status. Also, neurological status was documented by video before and during chronic stimulation. Magnetic resonance imaging studies were performed to show the anatomical localization of the electrode leads. Five patients showed a progressive improvement within 7 days. One patient with cervical dystonia and Meige's syndrome showed no improvement for 3 months, but beneficial effects were observed after 12 months. On average, the BFM movement scale scores decreased by 72.5% and Tsui scale scores by 63%. SF-36 showed an improvement in health status by an average of 36% according to eight different health categories. We conclude that chronic high-frequency Gpi stimulation in different types of dystonia is a very effective and safe treatment.