Development and validation of the Myasthenia Gravis TeleScore (MGTS).

OBJECTIVE: The aim of our study was to validate the Myasthenia Gravis TeleScore (MGTS), a scale for the evaluation of MG patients in telemedicine. INTRODUCTION: COVID-19 pandemic has boosted telemedicine in clinical practice. It could be crucial in the care of neurological patients with chronic disease. However, there is a lack of validated disease-specific tools to evaluate MG patients in telemedicine. METHODS: The MGTS included ten items divided in four districts: ocular, generalized muscular strength, bulbar, and respiratory. Patients were assessed with two different scales: the MGTS and the INCB-MG chosen as a reference from which MGTS was partially derived. Visit in presence with INCB-MG and televisit with MGTS were performed consecutively. Televisit was conducted by another neurologist between two rooms. A blind method was adopted. The strength of correlation was determined by the correlation coefficient (r); analysis of covariance (ANOVA-Kruskal-Wallis test) was used to compare subgroups. Significance was set to p < 0.05. RESULTS: One hundred thirty-one patients were included in the study, 71 females and 60 males. The Spearman correlation coefficient between the INCB-MG scale and the MGTS was 0.825 (p < 0.001), indicating a very strong correlation between them. Different items showed different correlations from low to high (0.32 to 0.80). As expected, correlation was lower between items with different evaluation modality (anamnestic vs clinical). DISCUSSION: The MGTS demonstrated a good correlation with INCB-MG, reliability and construct validity.

Atypical Post-Injection Reactions with Delayed Onset Following Glatiramer Acetate 40 mg: Need for Titration?

BACKGROUND: Glatiramer acetate (GA) 20 mg/day (GA20) is associated with immediate post-injection reactions (PIRs). For convenience of use, approved GA 40 mg three times weekly (GA40) delivers a similar weekly dose. The dose and concentration of a single GA40 injection are, however, twice as high as for GA20, and post-injection adverse events may differ. Cases of atypical PIRs to GA40 prompted us to systematically monitor such events. OBJECTIVE: The aim was to characterize atypical PIRs in multiple sclerosis (MS) patients treated with GA40. METHODS: Clinical practice data were prospectively collected in consecutive relapsing-remitting MS patients. Descriptive statistics for categorical and continuous variables, Mann-Whitney and Chi-squared tests for baseline comparisons, and Cox regression models for association of variables to first atypical PIRs were applied. RESULTS: Forty-six out of 173 patients (26.6%) given GA40 experienced any PIRs. Of those, 38 (22.0%) had atypical, 14 (8.1%) had combined typical and atypical, and 26 (15.0%) had recurrent atypical PIRs, most frequently shivering (13.3%) and nausea/vomiting (8.1%). Compared to typical PIRs, onset of atypical PIRs was significantly delayed (median 30 vs 1 min, p < 0.0001), and their median duration longer (median 120 vs 6 min, p = 0.00013). Previous exposure to GA20 was associated with a lower risk of atypical PIRs [hazard ratio (HR) = 0.35, 95% confidence interval (CI) 0.17-0.72, p = 0.0039]. Patients experiencing PIRs with GA20 were at elevated risk for atypical PIRs with GA40 (HR = 5.75, 95% CI 1.66-19.94, p = 0.0059). CONCLUSIONS: Atypical PIRs with GA40, especially gastrointestinal symptoms and/or fever/shivering, had a delayed onset and occurred in a significant proportion of our patients. Their real prevalence should be assessed in appropriately designed studies accounting for  nocebo responses. Initial dose titration might reduce PIR frequency.

Severe multiple sclerosis reactivation during prolonged lymphopenia after dimethyl fumarate discontinuation.

BACKGROUND: Delayed-release dimethyl fumarate (DMF) treatment can be associated with reduced lymphocyte and leucocyte counts, which might persist after DMF discontinuation. CASE PRESENTATION: We report the case of a patient with severe disease reactivation despite prolonged lymphopenia after DMF discontinuation. We describe the frequency and impact of prolonged lymphopenia after DMF discontinuation at two tertiary MS centres. A 36-year-old female patient with multiple sclerosis was switched to DMF after 14 years of treatment with interferon beta-1a. DMF was suspended after 4 months because of persistent lymphopenia for 3 months. Six months later, the patient had a severe relapse with multiple enhancing brain lesions at MRI although lymphopenia was still persistent. Haematological assessment excluded other causes of lymphopenia, which was evaluated as a probable iatrogenic complication of DMF. The patient was treated with i.v. methylprednisolone 1 gr daily for 3 days with clinical recovery. CONCLUSIONS: Prolonged lymphopenia after DMT discontinuation does not protect against disease reactivation. Starting a new immune therapy should be balanced against the option of a "wait and see." A different immunotherapeutic strategy such as an anti-B therapeutic approach could be considered.

Automated double-cone-beam CT fusion technique. Enhanced evaluation of glue distribution in cases of spinal dural arteriovenous fistula (SDAVF) embolisation.

OBJECTIVES: Spinal dural arteriovenous fistulas (SDAVFs) are acquired diseases that represent the majority of all arteriovenous spinal shunts, leading to progressive and disabling myelopathy. Treatment is focused on accurately disconnecting the fistula point. We present our experience with the double-cone-beam CT fusion technique successfully applied to evaluate treatment results in a series of SDAVFs. METHODS: Between November 2011 and December 2015 we performed double-DynaCT acquisition (pre- and post-embolisation) in 12 cases of SDAVF. RESULTS: A successful DynaCT fusion technique was only achieved in the group of patients with pre- and post-treatment images acquired at the same time as the treatment session, under general anaesthesia (4/12). DynaCT performed on different days proved to be inadequate for the automated fusion technique because of changes in the body position (8/12). CONCLUSIONS: A pre-treatment flat-panel cone-beam CT with contrast, at the time of diagnostic angiography, can be very helpful to detect the correct level of the fistula and the relationship between the fistula and the surrounding structures. In case of the endovascular approach, additional post-treatment native acquisition merged with the pre-treatment acquisition (double-cone-beam CT fusion technique) permits to immediately evaluate the distribution of the glue cast and to confirm the success of the procedure. KEY POINTS: • SDAVF treatment must be aimed to occlude the fistula point shunt. • Native post-operative cone-beam CT permits high-spatial-resolution imaging of the embolic cast. • The automated double-cone-beam CT fusion technique (pre/post) accurately demonstrates intravascular glue distribution after embolisation. • Patient movements should be avoided to obtain good technical results.

Early effect of dalfampridine in patients with MS: A multi-instrumental approach to better investigate responsiveness.

BACKGROUND: 4-aminopyridine (4-AP) is a potassium-channel blocker able to enhance walking speed in MS improving the action potentials of demyelinated axons on which internodal potassium channels are exposed. OBJECTIVE: to study early 4-AP effect with clinical, subjective, neurophysiological and neuroradiological tools. METHODS: Clinical (Timed 25-Foot Walk - T25FW, Timed Up-And-Go - TUG), subjective (MS Walking Scale-12 - MSWS-12), neurophysiological (Motor Evoked Potentials - MEPs) and imaging (Diffusion Tensor Imaging - DTI) evaluations were performed before (T0) and after (T1) 14days of 4-AP treatment. MEPs were recorded from Abductor Hallucis of both legs. A Tract-Based-Spatial-Statistics (TBSS) was performed on DTI. RESULTS: We found a significant difference between T0 and T1 for T25FW, TUG, MSWS-12 (p≤0.001) in the whole patients' sample (23 subjects, median EDSS 6.0) and decrease of Central Motor Conduction Time and increase of mean Amplitude (Amp) at T1 (p=0.008 and p=0.006). We also recorded a significant difference of T25FW, TUG, MSWS-12 and Amp in clinical responder (CR) patients (CR: amelioration >20% at T25FW). TBSS showed a significant Mean and Radial Diffusivity reduction in the corticospinal tracts (p<0.05) of the whole group of patients; this reduction was also found in the CR subgroup. CONCLUSION: Neurophysiological and neuroradiological parameters were modified in MS patients treated with 4-AP, and most of them reported a subjective improvement of their motor performances after treatment. The use of clinical, subjective, neurophysiological and neuroradiological tools could help to better explore MS patients responsiveness to 4-AP.

Titin antibodies in "seronegative" myasthenia gravis--A new role for an old antigen.

Myasthenia gravis (MG) is an autoimmune disease caused by antibodies targeting the neuromuscular junction of skeletal muscles. Triple-seronegative MG (tSN-MG, without detectable AChR, MuSK and LRP4 antibodies), which accounts for ~10% of MG patients, presents a serious gap in MG diagnosis and complicates differential diagnosis of similar disorders. Several AChR antibody positive patients (AChR-MG) also have antibodies against titin, usually detected by ELISA. We have developed a very sensitive radioimmunoprecipitation assay (RIPA) for titin antibodies, by which many previously negative samples were found positive, including several from tSN-MG patients. The validity of the RIPA results was confirmed by western blots. Using this RIPA we screened 667 MG sera from 13 countries; as expected, AChR-MG patients had the highest frequency of titin antibodies (40.9%), while MuSK-MG and LRP4-MG patients were positive in 14.6% and 16.4% respectively. Most importantly, 13.4% (50/372) of the tSN-MG patients were also titin antibody positive. None of the 121 healthy controls or the 90 myopathy patients, and only 3.6% (7/193) of other neurological disease patients were positive. We thus propose that the present titin antibody RIPA is a useful tool for serological MG diagnosis of tSN patients.

MuSK autoantibodies in myasthenia gravis detected by cell based assay--A multinational study.

Seronegative myasthenia gravis (MG) presents a serious gap in MG diagnosis and understanding. We applied a cell based assay (CBA) for the detection of muscle specific kinase (MuSK) antibodies undetectable by radioimmunoassay. We tested 633 triple-seronegative MG patients' sera from 13 countries, detecting 13% as positive. MuSK antibodies were found, at significantly lower frequencies, in 1.9% of healthy controls and 5.1% of other neuroimmune disease patients, including multiple sclerosis and neuromyelitis optica. The clinical data of the newly diagnosed MuSK-MG patients are presented. 27% of ocular seronegative patients were MuSK antibody positive. Moreover, 23% had thymic hyperplasia suggesting that thymic abnormalities are more common than believed.

A comprehensive analysis of the epidemiology and clinical characteristics of anti-LRP4 in myasthenia gravis.

Double-seronegative myasthenia gravis (dSN-MG, without detectable AChR and MuSK antibodies) presents a serious gap in MG diagnosis and understanding. Recently, autoantibodies against the low-density lipoprotein receptor-related protein 4 (LRP4) have been identified in several dSN-MG sera, but with dramatic frequency variation (∼2-50%). We have developed a cell based assay (CBA) based on human LRP4 expressing HEK293 cells, for the reliable and efficient detection of LRP4 antibodies. We have screened about 800 MG patient sera from 10 countries for LRP4 antibodies. The overall frequency of LRP4-MG in the dSN-MG group (635 patients) was 18.7% but with variations among different populations (range 7-32.7%). Interestingly, we also identified double positive sera: 8/107 anti-AChR positive and 10/67 anti-MuSK positive sera also had detectable LRP4 antibodies, predominantly originating from only two of the participating groups. No LRP4 antibodies were identified in sera from 56 healthy controls tested, while 4/110 from patients with other neuroimmune diseases were positive. The clinical data, when available, for the LRP4-MG patients were then studied. At disease onset symptoms were mild (81% had MGFA grade I or II), with some identified thymic changes (32% hyperplasia, none with thymoma). On the other hand, double positive patients (AChR/LRP4-MG and MuSK/LRP4-MG) had more severe symptoms at onset compared with any single positive MG subgroup. Contrary to MuSK-MG, 27% of ocular dSN-MG patients were LRP4 antibody positive. Similarly, contrary to MuSK antibodies, which are predominantly of the IgG4 subtype, LRP4 antibodies were predominantly of the IgG1 and IgG2 subtypes. The prevalence was higher in women than in men (female/male ratio 2.5/1), with an average disease onset at ages 33.4 for females and 41.9 for males. Overall, the response of LRP4-MG patients to treatment was similar to published responses of AChR-MG rather than to MuSK-MG patients.

Detection of poliovirus-infected macrophages in thymus of patients with myasthenia gravis.

BACKGROUND: Genetic and environmental factors are thought to contribute to the etiology of the autoimmune disease myasthenia gravis (MG). Viral involvement has long been suspected, but direct evidence of involvement has not been found. We recently reported that Toll-like receptor 4 (TLR4)-a key activator of innate immunity-was overexpressed in the thymus of some patients with MG, suggesting that thymic infection by pathogens might be involved in MG pathogenesis. We searched for evidence of intrathymic infection in patients with MG. METHODS: Twenty-seven MG thymuses (6 involuted, 7 hyperplastic, 5 thymitis, and 9 thymoma) previously tested for TLR4 expression, 18 nonpathologic control thymuses, and 10 pathologic control thymuses from patients without MG (8 thymoma and 2 hyperplastic) were analyzed for cytomegalovirus, varicella-zoster virus, herpes simplex virus types 1 and 2, eubacteria, respiratory syncytial virus, and enteroviruses using PCR techniques. Immunohistochemistry and double immunofluorescence were used to detect enterovirus capsid protein VP1 in thymic specimens and analyze TLR4 expression in VP1-positive cells. RESULTS: Poliovirus was detected in 4 MG thymuses (14.8%; 2 thymitis and 2 thymoma). No virus was detected in any control thymus. A linear correlation between plus and minus strand poliovirus RNA levels was observed in all 4 thymuses, suggesting persistent thymic infection. VP1 protein was detected in the cytoplasm of CD68-positive macrophages scattered through thymic medulla in all PV-positive thymuses. VP1 and TLR4 colocalized in infected cells. CONCLUSIONS: Poliovirus-infected macrophages are present in thymus of some patients with myasthenia gravis, suggesting a viral contribution to the intrathymic alterations leading to the disease.

Sequential antibodies to potassium channels and glutamic acid decarboxylase in neuromyotonia.

A patient with thymoma-associated neuromyotonia and voltage-gated potassium channel (Kv1.2 and Kv1.6) antibodies by immunoprecipitation and rat brain immunolabeling was treated successfully with immunoadsorption and cyclophosphamide. Curiously, glutamic acid decarboxylase antibodies, absent at onset, appeared later. Stiff-person syndrome was absent, but fast blink reflex recovery suggested enhanced brainstem excitability. The range of antibodies produced in thymoma-associated neuromyotonia is richer, and the timing of antibody appearance more complex, than previously suspected.

Pathogenesis, diagnosis and treatment of Rasmussen encephalitis: a European consensus statement.

Rasmussen encephalitis (RE) is a rare but severe immune-mediated brain disorder leading to unilateral hemispheric atrophy, associated progressive neurological dysfunction and intractable seizures. Recent data on the pathogenesis of the disease, its clinical and paraclinical presentation, and therapeutic approaches are summarized. Based on these data, we propose formal diagnostic criteria and a therapeutic pathway for the management of RE patients.

Experience with immunomodulatory treatments in Rasmussen's encephalitis.

The authors investigated immunomodulatory treatments in 15 patients with Rasmussen encephalitis (RE) (14 with childhood and one with adolescent onset RE). Positive time-limited responses were obtained in 11 patients using variable combinations of corticosteroids, apheresis, and high-dose IV immunoglobulins. Although surgical exclusion of the affected hemisphere is the only treatment that halts disease progression, immunomodulation can be considered when early surgery is not feasible, in late-onset patients with slower disease progression, and in the few cases of bilateral disease.

Myasthenia gravis and myasthenic syndrome.

Myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) are autoimmune ion channel disorders mediated by antibodies to postsynaptic acetylcholine receptors and presynaptic voltage-operated calcium channels, respectively. MG and LEMS are currently treated with corticosteroids and immunosuppressive drugs with a positive clinical outcome. Since both diseases are mediated by circulating autoantibodies, they are good candidates for immunomodulation by intravenous immunoglobulins (IVIG). Standardized controlled studies are lacking in this field, but there is general agreement that IVIG are effective. They can be used as an acute treatment to control temporarily the most severe forms of these diseases, as well as a chronic immunomodulating therapy in addition to standard pharmacological treatment. Several aspects of IVIG administration, cost benefit-analysis, and comparison to plasmapheresis are still needed.

Similar binding to glutamate receptors by Rasmussen and partial epilepsy patients' sera.

Immunoreactivity of sera from patients with Rasmussen encephalitis (RE) and patients with partial epilepsy (PE) was analyzed by immunohistoblot on rat brain sections and the staining pattern compared with that obtained with antibodies to a-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid and NMDA receptors. Staining for anti-glutamate receptor 3 (GluR3) was found in 82% of patients with RE and 64% of patients with PE. Histoblot analysis showed a positive staining in GluR3- and NMDA-specific regions of rat brain, providing a comprehensive CNS immunolocalization.

Labeling of rat neurons by anti-GluR3 IgG from patients with Rasmussen encephalitis.

The authors report the immunocytochemical localization in rat brain of affinity-purified anti-GluR3 (glutamate receptor) antibodies from two patients with Rasmussen encephalitis (RE) and from immunized rabbits. The distribution of immunolabeling was similar using antibodies from rabbits and patients with RE. No electrophysiologic responses were elicited from acutely dissociated kainate-responsive neurons isolated from rat brain when these antibodies were applied. These findings show that anti-GluR3 antibodies purified from patients with RE bind to specific regions of the CNS but do not act through an excitotoxic mechanism.

Epileptic phenotypes associated with mitochondrial disorders.

OBJECTIVE: To define the clinical and EEG features of the epileptic syndromes occurring in adult and infantile mitochondrial encephalopathies (ME). METHODS: Thirty-one patients with recurrent and apparently unprovoked seizures associated with primary ME were included in the study. Diagnosis of ME was based on the recognition of a morphologic, biochemical, or molecular defect. RESULTS: Epileptic seizures were the first recognized symptom in 53% of the patients. Many adults (43%) and most infants (70%) had nontypical ME phenotypes. Partial seizures, mainly with elementary motor symptoms, and focal or multifocal EEG epileptiform activities characterized the epileptic presentation in 71% of the patients. Generalized myoclonic seizures were an early and consistent symptom only in the five patients with an A8344G mitochondrial DNA point mutation with classic myoclonus epilepsy with ragged red fibers (MERRF) syndrome or "overlapping" characteristics. Photoparoxysmal EEG responses were observed not only in patients with typical MERRF, but also in adult patients with ME with lactic acidosis and strokelike episodes (MELAS), or overlapping phenotypes, and in one child with Leigh syndrome. CONCLUSIONS: Epilepsy is an important sign in the early presentation of ME and may be the most apparent neurologic sign of nontypical ME, often leading to the diagnostic workup. Except for those with an A8344G mitochondrial DNA point mutation, most of our patients had partial seizures or EEG signs indicating a focal origin.

A novel mtDNA mutation in the ND5 subunit of complex I in two MELAS patients.

We identified a novel heteroplasmic mutation in the mitochodrial DNA gene encoding the ND5 subunit of complex I. This mutation (13514A-->G) hits the same codon affected by a previously reported mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS)-associated mutation (13513G-->A), but the amino acid replacement is different (D393G vs D393N). The 13514A-->G mutation was found in two unrelated MELAS-like patients. However, in contrast to typical MELAS, lactic acidosis was absent or mild and the muscle biopsy was morphologically normal. Strongly positive correlation between the percentage of heteroplasmy and defective activity of complex I was found in cybrids. We found an additional 13513G-->A-positive case, affected by a progressive mitochondrial encephalomyopathy. Our results clearly demonstrate that the amino acid position D393 is crucial for the function of complex I. Search for D393 mutations should be part of the routine screening for mitochondrial disorders.

Phenotypic manifestations associated with CAG-repeat expansion in the androgen receptor gene in male patients and heterozygous females: a clinical and molecular study of 30 families.

Spinal and bulbar muscular atrophy (Kennedy disease) is an adult form of X-linked motor neuron disease caused by the expansion of a polymorphic CAG-repeat sequence in the first exon of the androgen receptor gene. We studied clinical and molecular features of 36 patients and 19 heterozygous females. Phenotypic manifestations and disease severity broadly varied among our spinal and bulbar muscular atrophy patients. The size of CAG expansion significantly influences the age of disease onset, but neither clinical features nor disease severity. The majority of carrier women presented signs of chronic denervation at neurophysiological examination and, in three cases, low-amplitude sensory action potentials were recorded. Notably, a few women developed mild signs of bulbar motor neuron impairment later in life. The identification of a large number of patients by the use of the molecular test further supports the hypothesis that Kennedy disease had been previously underdiagnosed, probably because of the great variability of clinical presentation. Although an early diagnosis may not be crucial for treatment, given the lack of effective therapy, the molecular testing can be of great relevance for disease prognosis and genetic counseling.

Oral administration of an immunodominant T-cell epitope downregulates Th1/Th2 cytokines and prevents experimental myasthenia gravis.

The mucosal administration of the native antigen or peptide fragments corresponding to immunodominant regions is effective in preventing or treating several T cell-dependent models of autoimmune disease. No data are yet available on oral tolerance with immunodominant T-cell peptides in experimental autoimmune myasthenia gravis (EAMG), an animal model of B cell-dependent disease. We report that oral administration of the T-cell epitope alpha146-162 of the Torpedo californica acetylcholine receptor (TAChR) alpha-subunit suppressed T-cell responses to AChR and ameliorated the disease in C57Bl/6 (B6) mice. Protection from EAMG was associated with reduced serum Ab's to mouse AChR and reduced AChR loss in muscle. The effect of Talpha146-162 feeding was specific; treatment with a control peptide did not affect EAMG manifestations. The protective effect induced by peptide Talpha146-162 was mediated by reduced production of IFN-gamma, IL-2, and IL-10 by TAChR-reactive cells, suggesting T-cell anergy. TGF-beta-secreting Th3 cells did not seem to be involved in tolerance induction. We therefore demonstrate that feeding a single immunodominant epitope can prevent an Ab-mediated experimental model of autoimmune disease.