scholarly journals Repetitive ocular vestibular evoked myogenic potentials in myasthenia gravis

Neurology ◽  
2020 ◽  
Vol 94 (16) ◽  
pp. e1693-e1701 ◽  
Author(s):  
Robert H.P. de Meel ◽  
Kevin R. Keene ◽  
Magdalena A. Wirth ◽  
Konrad P. Weber ◽  
Umesh A. Badrising ◽  
...  
Keyword(s):  
Myasthenia Gravis ◽  
Neuromuscular Diseases ◽  
Added Value ◽  
Vestibular Evoked Myogenic Potentials ◽  
Congenital Myasthenic Syndrome ◽  
Healthy Controls ◽  
Class Iii ◽  
Repetitive Nerve Stimulation ◽  
Myasthenic Syndrome

ObjectiveTo validate the repetitive ocular vestibular evoked myogenic potentials (RoVEMP) test for diagnostic use in myasthenia gravis (MG) and to investigate its value in diagnostically challenging subgroups.MethodsThe RoVEMP test was performed in 92 patients with MG, 22 healthy controls, 33 patients with a neuromuscular disease other than MG (neuromuscular controls), 4 patients with Lambert-Eaton myasthenic syndrome, and 2 patients with congenital myasthenic syndrome.ResultsMean decrement was significantly higher in patients with MG (28.4% ± 32.2) than in healthy controls (3.2% ± 13.9; p < 0.001) or neuromuscular controls (3.8% ± 26.9; p < 0.001). With neuromuscular controls as reference, a cutoff of ≥14.3% resulted in a sensitivity of 67% and a specificity of 82%. The sensitivity of the RoVEMP test was 80% in ocular MG and 63% in generalized MG. The RoVEMP test was positive in 6 of 7 patients with seronegative MG (SNMG) with isolated ocular weakness. Of 10 patients with SNMG with negative repetitive nerve stimulation (RNS) results, 73% had an abnormal RoVEMP test. The magnitude of decrement was correlated with the time since the last intake of pyridostigmine (B = 5.40; p = 0.019).ConclusionsThe RoVEMP test is a new neurophysiologic test that, in contrast to RNS and single-fiber EMG, is able to measure neuromuscular transmission of extraocular muscles, which are the most affected muscles in MG. Especially in diagnostically challenging patients with negative antibody tests, negative RNS results, and isolated ocular muscle weakness, the RoVEMP test has a clear added value in supporting the diagnosis of MG.Classification of evidenceThis study provides Class III evidence that RoVEMP distinguishes MG from other neuromuscular diseases.

Ophthalmoplegia

2015 ◽  
Author(s):  
Aziz Shaibani
Keyword(s):  
Family History ◽  
Muscular Dystrophy ◽  
Myasthenia Gravis ◽  
Eye Movement ◽  
Congenital Myasthenic Syndrome ◽  
Oculopharyngeal Muscular Dystrophy ◽  
Detailed Family History ◽  
Myasthenic Syndrome ◽  
The Brain

Ophthalmoplegia is usually chronic and therefore diplopia is not a feature. There is enough time for the brain to suppress one image. It is amazing how much impairment of eye movement has to occur before the patient becomes concerned or considers it as abnormal. Neglected myasthenia gravis may be confused with mitochondrial ophthalmoplegia or oculopharyngeal muscular dystrophy or even congenital myasthenic syndrome. Central cause of ophthalmoplegia should be ruled out first by performing doll’s eye movement. Detailed family history looking in particular for ptosis, ophthalmoplegia, and dysphagia is diagnostically very useful. Non neurological causes of ophthalmoplegia such as severe exophthalmus, and retroorbital pathology should be considered.

scholarly journals Evaluation of a novel immunoassay to detect p-tau Thr217 in the CSF to distinguish Alzheimer disease from other dementias

Neurology ◽  
2020 ◽  
Vol 95 (22) ◽  
pp. e3026-e3035
Author(s):  
Jozef Hanes ◽  
Andrej Kovac ◽  
Hlin Kvartsberg ◽  
Eva Kontsekova ◽  
Lubica Fialova ◽  
...  
Keyword(s):  
Alzheimer Disease ◽  
Positive Predictive Value ◽  
Diagnostic Accuracy ◽  
Predictive Value ◽  
Healthy Controls ◽  
Class Iii ◽  
Total Tau ◽  
Β Amyloid ◽  
Healthy Participants

ObjectiveTo investigate whether tau phosphorylated at Thr217 (p-tau T217) assay in CSF can distinguish patients with Alzheimer disease (AD) from patients with other dementias and healthy controls.MethodsWe developed and validated a novel Simoa immunoassay to detect p-tau T217 in CSF. There was a total of 190 participants from 3 cohorts with AD (n = 77) and other neurodegenerative diseases (n = 69) as well as healthy participants (n = 44).ResultsThe p-tau T217 assay (cutoff 242 pg/mL) identified patients with AD with accuracy of 90%, with 78% positive predictive value (PPV), 97% negative predictive value (NPV), 93% sensitivity, and 88% specificity, compared favorably with p-tau T181 ELISA (52 pg/mL), showing 78% accuracy, 58% PPV, 98% NPV, 71% specificity, and 97% sensitivity. The assay distinguished patients with AD from age-matched healthy controls (cutoff 163 pg/mL, 98% sensitivity, 93% specificity), similarly to p-tau T181 ELISA (cutoff 60 pg/mL, 96% sensitivity, 86% specificity). In patients with AD, we found a strong correlation between p-tau T217 and p-tau T181, total tau and β-amyloid 40, but not β-amyloid 42.ConclusionsThis study demonstrates that p-tau T217 displayed better diagnostic accuracy than p-tau T181. The data suggest that the new p-tau T217 assay has potential as an AD diagnostic test in clinical evaluation.Classification of evidenceThis study provides Class III evidence that a CSF immunoassay for p-tau T217 distinguishes patients with AD from patients with other dementias and healthy controls.

Skin nerve phosphorylated α-synuclein deposits in idiopathic REM sleep behavior disorder

Neurology ◽  
2017 ◽  
Vol 88 (22) ◽  
pp. 2128-2131 ◽  
Author(s):  
Elena Antelmi ◽  
Vincenzo Donadio ◽  
Alex Incensi ◽  
Giuseppe Plazzi ◽  
Rocco Liguori
Keyword(s):  
Skin Biopsy ◽  
Rem Sleep ◽  
Rem Sleep Behavior Disorder ◽  
Behavior Disorder ◽  
Healthy Controls ◽  
Class Iii ◽  
Immunofluorescence Method ◽  
Nonmotor Symptoms ◽  
Sleep Behavior

Objective:To test if phosphorylated α-synuclein (p-α-syn) deposits can be detected by means of skin biopsy in patients with idiopathic REM sleep behavior disorder (iRBD) as a potential early histopathologic marker of impending synucleinopathy.Methods:Proximal (cervical) and distal (legs) samples of skin biopsy were obtained from 12 patients with polysomnographically confirmed iRBD and 55 sex- and age-matched healthy controls (HC). P-α-syn deposits were assessed with a monoclonal antibody against p-α-syn at serine 129, disclosed by an immunofluorescence method. In addition, patients underwent an extensive workup in order to search for nonmotor symptoms and neuroimaging findings usually associated with impending neurodegeneration and to exclude subtle motor or cognitive signs.Results:P-α-syn deposits were detected in 9 (75%) out of 12 patients with iRBD and none of the HC. In iRBD, the sensitivity of the test was higher at the cervical site (67%) when compared to the leg site (58%).Conclusions:Our preliminary findings suggest that skin biopsy in patients with iRBD might be a safe and sensitive procedure to be further tested in order to detect p-α-syn deposits in the premotor stage of synucleinopathies.Classification of evidence:This study provides Class III evidence that p-α-syn skin deposits identify patients with iRBD.

Ophthalmoplegia

2018 ◽  
Author(s):  
Aziz Shaibani
Keyword(s):  
Muscular Dystrophy ◽  
Myasthenia Gravis ◽  
Eye Movement ◽  
Congenital Myasthenic Syndrome ◽  
Oculopharyngeal Muscular Dystrophy ◽  
Laboratory Methods ◽  
Different Types ◽  
Myasthenic Syndrome ◽  
The Brain

Ophthalmoplegia is usually chronic, and therefore diplopia is not a feature. There is enough time for the brain to suppress one image. It is amazing how much of impairment of eye movement has to occur before the patient becomes concerned or considers it as abnormal. Neglected myasthenia gravis (MG) may be confused with mitochondrial ophthalmoplegia or oculopharyngeal muscular dystrophy (OPMD) or even congenital myasthenic syndrome (CMS). Central causes of ophthalmoplegia should be ruled out first by performing doll’s eye movement. A number of cases of different types of ophthalmoplegia are presented, along with clinical and laboratory methods to differentiate them.

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