Single fiber EMG as a prognostic tool in myasthenia gravis

Introduction: Single fiber electromyography (SFEMG) is the most sensitive diagnostic tool for diagnosis of myasthenia gravis (MG). Its prognostic value is not known. Methods: We retrospectively analyzed the clinical course of 232 MG patients who presented with only mild symptoms and had SFEMG of the orbicularis oculi muscle. We correlated their SFEMG results with the severity of their later clinical course. Results: During the observation period 39 patients (17%) developed severe disease exacerbations, and 193 (83%) remained stable. Patients with severe disease exacerbation had a significantly higher mean jitter value (P < 0.0001), a greater percentage of fibers with increased jitter (P < 0.0001), and/or impulse blocking (P < 0.0001) on SFEMG. Conclusions: The extent of the SFEMG abnormalities in this study correlated with the later clinical course of MG. Muscle Nerve 54 : 1034–1040, 2016     

Accuracy of the ice test in the diagnosis of myasthenia gravis in patients with ptosis

Introduction: Several studies have reported high diagnostic sensitivity and specificity for the ice test in myasthenia gravis. All of the studies employed a case–control design, in which the diagnosis was already known at the time of the test for both patients and controls, leading to case selection bias. This suggests that the available literature substantially overestimates the diagnostic utility of these tests. Methods: A retrospective cohort study without selection bias was performed to examine the sensitivity and specificity of the ice test. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the ice test were determined by means of a 2 × 2 table. Results: The ice test has a sensitivity of 0.92 (95% CI 0.62–1.00), specificity of 0.79 (95% CI 0.56–1.00), PPV of 0.73 (95% CI 0.48–0.90), and NPV of 0.94 (95% CI 0.70–1.00). Conclusions: Due to its high negative predictive value the ice test is still a reliable and useful bed‐side test. Muscle Nerve 48 : 902–904, 2013     

Value of angiographic regional circulation signs in predicting hemorrhagic transformation after endovascular thrombectomy

ObjectiveThe aim of this study was to evaluate the predictive value of the early venous filling (EVF) sign, the basal ganglia blush (BGB) sign and both the EVF and BGB signs for the hemorrhagic transformation (HT) and parenchymal hematoma (PH) in patients after endovascular thrombectomy.MethodsThis study included patients with anterior circulation large vessel occlusive stroke treated with endovascular thrombectomy from May 2017 to December 2021. The predictive value of regional circulation signs for HT and PH were assessed using logistic regression models adjusted for confounders, and further a multiplicative interaction term was added to investigate the effect of different stroke severity on its predictive value.ResultsAmong the 350 patients included and after adjusting for confounders, those with the EVF sign (adjusted OR=3.934, 95% CI:2.326–6.655), the BGB sign (adjusted OR=3.776, 95% CI:2.341–6.089), and both the EVF and BGB signs (adjusted OR=3.250, 95% CI: 1.886–5.600) were more likely to have HT. The EVF sign (adjusted OR=3.545, 95% CI:2.036–6.170), the BGB sign (adjusted OR=3.742, 95% CI:2.110–6.639), and both the EVF and BGB signs (adjusted OR=3.139, 95% CI: 1.776–5.549) were also significantly correlated with PH. When stratified according to stroke severity, we further found there were significant interactions between regional circulation signs and stroke severity on postoperative HT and PH (all P for interaction < 0.001).ConclusionsRegional circulation signs were independently associated with HT and PH after endovascular thrombectomy and had a higher predictive value in patients with severe stroke compared with mild to moderate stroke.     

Single fiber electromyography of extraocular muscles: A sensitive method for the diagnosis of ocular myasthenia gravis

We performed single fiber electromyography (SFEMG) in the superior rectus and levator palpebralis (SR-LP) muscles of 17 patients with pure ocular myasthenia gravis (MG) and 9 controls. Thirteen patients were also assessed with SFEMG in the orbicularis oculi (OO) muscle. All the MG patients but none of the control subjects showed abnormal SFEMG jitter in the SR-LP muscles. On the other hand, only 62% of the MG patients had abnormal SFEMG jitter in the OO muscle. The procedure was well tolerated by the patients, and complications were minor. We conclude that SFEMG of the SR–LP muscles is a safe and highly sensitive technique for the diagnosis of ocular MG. © 1995 John Wiley & Sons, Inc.     

Miastenia gravis ocular y factores asociados al desarrollo de una generalización secundaria: descripción de una serie española

IntroductionOcular myasthenia gravis (MG) is the most common phenotype of MG at onset. A variable percentage of these patients develop secondary generalisation; the risk factors for conversion and the protective effect of immunosuppressive treatment are currently controversial.Patients and methodsWe designed a retrospective single-centre study with the aim of describing the demographic, clinical, and laboratory characteristics of a Spanish cohort of patients with ocular MG from Hospital Universitario de Albacete from January 2008 to February 2020.ResultsWe selected 62 patients with ocular MG from a cohort of 91 patients with MG (68.1%). Median age at diagnosis was 68 (IQR, 52-75.3), and men accounted for 61.3% of the sample (n = 38). Most patients presented very late-onset ocular MG (n = 34, 54.8%). Binocular diplopia was the most frequent initial symptom (51.7%). The rate of progression to generalised MG was 50% (n = 31), with a median time of 6 months (IQR, 2-12.8). Female sex (OR: 5.46; 95% CI, 1.16-25-74; p = .03) and anti–acetylcholine receptor antibodies (OR: 8.86; 95% CI, 1.15-68.41; p = .04) were significantly associated with the risk of developing generalised MG.ConclusionsThe conversion rate observed in our series is relatively high. Generalisation of MG mainly occurs during the first 2 years of progression, and is strongly associated with female sex and especially with the presence of anti–acetylcholine receptor antibodies.     

Diagnostic accuracy of various EEG changes during carotid endarterectomy to detect 30-day perioperative stroke: A systematic review

ObjectivesWe assessed whether significant intraoperative electroencephalography (EEG) changes have predictive value for perioperative stroke within 30 days after carotid endarterectomy (CEA) procedures for carotid stenosis (CS) patients. We also assessed the diagnostic accuracy of various EEG changes in predicting perioperative stroke.MethodsWe searched databases for reports with outcomes of CS patients who underwent CEA with intraoperative EEG monitoring. We calculated the sensitivity, specificity, and diagnostic odds ratio (DOR) of EEG changes for predicting perioperative stroke. Sensitivity and specificity were presented with forest plots and a summary receiver operating characteristic (ROC) curve.ResultsThe meta-analysis included 10,672 patients. Intraoperative EEG changes predicted 30-day stroke with a sensitivity of 46% (95% CI, 38–54%) and specificity of 86% (95% CI, 83–88%). The estimated DOR was 5.79 (95% CI, 3.86–8.69). The estimated DOR for reversible and irreversible EEG changes were 8.25 (95% CI, 3.34–20.34) and 70.84 (95% CI, 36.01–139.37), respectively.ConclusionIntraoperative EEG changes have high specificity but modest sensitivity for predicting perioperative stroke following CEA. Patients with irreversible EEG changes are at high risk for perioperative stroke.SignificanceIntraoperative EEG changes can help surgeons predict the risk of perioperative stroke for CS patients following CEA.     

Performance of dual layer dual energy CT virtual monoenergetic images to identify early ischemic changes in patients with anterior circulation large vessel occlusion

Background and purposeDual energy CT is increasingly available and used in the standard diagnostic setting of ischemic stroke patients. We aimed to evaluate how different dual energy CT virtual monoenergetic energy levels impact identification of early ischemic changes, compared to conventional polyenergetic CT images.Materials and methodsThis retrospective single-center study included patients presenting with acute ischemic stroke caused by an occlusion of the intracranial internal carotid artery or proximal middle cerebral artery. Data was gathered on consecutive patients admitted to our institution who underwent initial diagnostic stroke imaging with dual layer dual energy CT and a subsequent follow-up CT one to three days after admission. Automated ASPECTS results from conventional polyenergetic and different virtual monoenergetic energy level reconstructions at admission were generated and compared to reference standard ASPECTS. Confidence intervals (CI) for sensitivity, specificity, negative and positive predictive value were calculated.ResultsA total of 24 patients were included. Virtual monoenergetic reconstructions of 70 keV had the highest region-based ASPECTS accuracy, 0.90 (sensitivity 0.82 (95% CI 0.72–0.93), specificity 0.92 (0.88–0.97), negative predictive value 0.94 (0.90–0.96)), whereas virtual monoenergetic reconstructions of 40 keV had the lowest, 0.77 (sensitivity 0.34 (0.26–0.42), specificity 0.90 (0.89–0.96), negative predictive value 0.80 (0.77–0.83)).ConclusionsAutomated 70 keV ASPECTS had the highest diagnostic accuracy, sensitivity and negative predictive value overall. Our results indicate that virtual monoenergetic energy levels impact the identification of early ischemic changes on CT.     

重症肌无力单纤维肌电图测定

57例MG患者和40例健康正常人分别进行了SFEMG检查,部分患者同时进行重复电刺激和SFEMG进行比较。结果发现:MG患者SFEMG阳性率为82.5％。按MG分型:眼肌型阳性率为58.3％,全身型阳性率为100％。而重复电刺激阳性率仅为64％。同时SFEMG的个体MCD均值大小及Jitter阻滞率与病程无关,与病型和病情有关。SFEMG是诊断MG敏感的电生理检查方法。     

Reference values for voluntary and stimulated single-fibre EMG using concentric needle electrodes: a multicentre prospective study

ObjectiveThe aim of this study is to establish reference values for single-fibre electromyography (SFEMG) using concentric needles in a prospective, multicentre study.MethodsVoluntary or stimulated SFEMG at the extensor digitorum communis (EDC) or frontalis (FRO) muscles was conducted in 56–63 of a total of 69 normal subjects below the age of 60 years at six Japanese institutes. The cut-off values for mean consecutive difference (MCD) of individual potentials were calculated using +2.5 SD or 95% prediction limit (one-tail) of the upper 10th percentile MCD value for individual subjects.ResultsThe cut-off values for individual MCD (+2.5 SD) were 56.8 μs for EDC-V (voluntary SFEMG for EDC), 58.8 μs for EDC-S (stimulated SFEMG for EDC), 56.8 μs for FRO-V (voluntary SFEMG for FRO) and 51.0 μs for FRO-S (stimulated SFEMG for FRO). The false positive rates using these cut-off values were around 2%.ConclusionsThe +2.5 SD and 95% prediction limit might be two optimal cut-off values, depending on the clinical question. The obtained reference values were larger than those reported previously using concentric needles, but might better coincide with conventional values.SignificanceThis is the first multicentre study reporting reference values for SFEMG using concentric needles. The way to determine cut-off values and the statistically correct definition of the percentile were discussed.     

Arterial-spin labeling MRI identifies residual cerebral arteriovenous malformation following stereotactic radiosurgery treatment

Background and purposeBrain arteriovenous malformation (AVM) treatment by stereotactic radiosurgery (SRS) is effective, but AVM obliteration following SRS may take two years or longer. MRI with arterial-spin labeling (ASL) may detect brain AVMs with high sensitivity. We determined whether brain MRI with ASL may accurately detect residual AVM following SRS treatment.Materials and methodsWe performed a retrospective cohort study of patients who underwent brain AVM evaluation by DSA between June 2010 and June 2015. Inclusion criteria were: (1) AVM treatment by SRS, (2) follow-up MRI with ASL at least 30 months after SRS, (3) DSA within 3 months of the follow-up MRI with ASL, and (4) no intervening AVM treatment between the MRI and DSA. Four neuroradiologists blindly and independently reviewed follow-up MRIs. Primary outcome measure was residual AVM indicated by abnormal venous ASL signal.Results15 patients (12 females, mean age 29 years) met inclusion criteria. There were three posterior fossa AVMs and 12 supratentorial AVMs. Spetzler–Martin (SM) Grades were: SM1 (8%), SM2 (33%), SM3 (17%), SM4 (25%), and SM5 (17%). DSA demonstrated residual AVM in 10 patients. The pooled sensitivity, specificity, positive predictive value, and negative predictive value of venous ASL signal for predicting residual AVM were 100% (95% CI: 0.9-1.0), 95% (95% CI: 0.7–1.0), 98% (95% CI: 0.9–1.0), and 100% (95% CI: 0.8–1.0), respectively. High inter-reader agreement as found by Fleiss’ Kappa analysis (k = 0.92; 95% CI: 0.8–1.0; P < 0.0001).ConclusionsASL is highly sensitive and specific in the detection of residual cerebral AVM following SRS treatment.     

Ocular myastyenia gravis: The diagnostic yield of repetitive nerve stimulation and stimulated single fiber EMG of orbicularis oculi muscle and infrared reflection oculography

For the diagnosis of ocular myasthenia gravis (ocular MG), testing of the muscles close to the affected ones may be important. The relative importance of several methods: stimulated single fiber EMG (stimulated SFEMG), repetitive nerve stimulation test (RNS) of orbicularis oculi muscle, and infrared reflection oculography (IROG) was investigated. Thirty-two patients in whom a diagnosis of ocular MG was considered on clinical grounds were admitted to the study. Based on the results of the three neurophysiological tests, the patients could be divided in three groups: a first group with an abnormal stimulated SFEMG, and an abnormal RNS and/or abnormal IROG; a second group with only a slightly abnormal stimulated SFEMG; and a third group with normal tests in all three tests. The clinical diagnosis of ocular MG was made in all 11 patients of the first group; in 86% (6 of 7) of the patients of the second group; and in 7% (1 of 14) of the patients of the third groups. This study demonstrates that the orbicularis oculi muscle is a suitable muscle for stimulated SFEMG in patients with ocular MG, and that the results obtained with this technique showed a better relation with the clinical diagnosis than those of the two other techniques. We also demonstrate that there is no additional value in studying the jitter with different stimulation rates in patients with suspected ocular MG. © 1993 John Wiley & Sons, Inc.     

RAPID Aneurysm: Artificial intelligence for unruptured cerebral aneurysm detection on CT angiography

ObjectivesCerebral aneurysms may result in significant morbidity and mortality. Identification of these aneurysms on CT Angiography (CTA) studies is critical to guide patient treatment. Artificial intelligence platforms to assist with automated aneurysm detection are of high interest. We determined the performance of a semi-automated artificial intelligence software program (RAPID Aneurysm) for the detection of cerebral aneurysms.Materials and MethodsRAPID Aneurysm was used to detect retrospectively the presence of cerebral aneurysms in CTA studies performed between January 2019 and December 2020. The gold standard was aneurysm presence and location as determined by the consensus of three expert neuroradiologists. Aneurysm detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by RAPID Aneurysm were determined.Results51 patients (mean age, 56±15; 24 women [47.1%]) with a single CTA were included. A total of 60 aneurysms were identified. RAPID Aneurysm had a sensitivity of 0.950 (95% CI: 0.863-0.983), specificity of 1.000 (95% CI: 0.996-1.000), a positive predictive value (PPV) of 1.000 (95% CI: 0.937-1.000), a negative predictive value (NPV) of 0.997 (95% CI: 0.991-0.999), and an accuracy of 0.997 (95% CI: 0.991-0.999) for cerebral aneurysm detection.ConclusionsRAPID Aneurysm is highly accurate for the detection of cerebral aneurysms on CTA.     

Does serum prolactin indicate the presence of seizure in the emergency department patient?

Abstract. Study objective: We sought to evaluate whether there was a correlation between elevated serum prolactin in patients presenting with the question of seizure. Methods: A Convenience sample of 200 consecutive patients were chosen who had a serum prolactin measurement in the setting of seizure activity. Results: The prolactin level was within a range of 3.90–294.00 mg/dl with an upper limit of normal being 29.9 mg/dl. Patients were ultimately diagnosed with seizure in 54.5% (109 of 200) with an abnormal prolactine in 31.0% (62 of 200). The sensitivity of this serum prolactin was 42%, the specificity was 82%, positive predictive value (PPV) of 74%, and negative predictive value (NPV) of 54%. There was an overall accuracy of 60% in the diagnosis of seizure, with a likelihood ratio of 2.4 (95% Confidence Interval [CI], 1.5–3.9). Conclusion: The measurement of serum prolactin is helpful as a confirmatory test, but not as screening test in the emergency department setting.     

Unattended sleep study in screening for sleep apnea in the acute phase of ischemic stroke

ObjectivesWe aimed to compare the feasibility of automatically and manually scored cardiorespiratory polygraphy results for sleep apnea screening in the acute phase of ischemic stroke.MethodsProspective study included 204 ischemic stroke patients, who underwent nocturnal unattended portable monitoring with three-channel device during 48 h after onset of stroke symptoms. Sleep apnea diagnosis was determined as a respiratory event index (REI) ≥5/hour.ResultsThe mean age of the patients was 67.7 years and 62.7% were males. Automatic scoring identified sleep apnea in 148/72.5% and manual scoring in 186/91.2% of patients, showing moderate agreement (Kappa value 0.407). Of the cohort, 39 (19.1%) patients fulfilled the criteria for diagnosis of central sleep apnea (CSA) (>50% of events central) and 165 (80.9%) had obstructive sleep apnea (OSA). Automatic scoring identified poorly the type of events, and missed 18.6% of recordings. Oxygen desaturation 4% index (ODI4), interclass correlation coefficient (ICC) value 0.993, (95% CI 0.990–0.994), lowest saturation (ICC value 0.989, 95% CI 0.985–0.991) and percent of time spent <90% (ICC value 0.987, 95% CI 0.982–0.990) showed excellent agreement. Interclass correlation value for REI was 0.869 (95% CI 0.828 to 0.901) and ICC value 0.848 (95% CI 0.800 to 0.885) for obstructive apnea index, both indicating good agreement. Automatic scoring underestimated the severity of sleep apnea.ConclusionsBoth automatically and manually scored results recognized sleep apnea, albeit manual scoring identified more sleep apnea. Sleep apnea diagnosis agreement was moderate. Underestimation of the severity of sleep apnea by automatic scoring may result in undertreatment of sleep apnea.Clinical trial registrationURL:http://www.clinicaltrials.cov. Unique identifier: NCT01861275.     

Diagnostic value of double-step nerve stimulation test in patients with Myasthenia Gravis

ObjectiveDouble-step nerve stimulation test (DSST) is a repetitive nerve stimulation (RNS) technique that is performed under exercise and ischemic conditions. We tested the diagnostic significance of DSST at a distal muscle in 17 control subjects and 10 myasthenic patients who had normal conventional RNS test.MethodsMyasthenia Gravis was diagnosed by SFEMG test and acetylcholine receptor antibody titers. During DSST decremental responses were noted. Sensitivity/specificity of DSST were evaluated by receiver operating characteristics (ROC) analysis and best variable in discrimination of myasthenic patients from control subjects with its optimal cutoff-point was selected.ResultsAt a selected cutoff-point, sensitivity and specificity of DSST reached up to 100%. Also DSST response patterns, especially during the resolution of ischemia, showed significant differences in MG patients. There was a delayed recovery in the ischemia–exercise aggravated decremental response after the resolution of ischemia in the patients when compared with rapid recovery in controls.ConclusionsBy using ROC derived cutoff-points, DSST could accurately discriminate MG patients from control subjects. Quantitative results of our study are limited by small series of patients and can vary with larger series. However we think that the difference between the decremental response patterns of patients and controls is a valuable finding.SignificanceDSST can be a sensitive, specific and non-invasive choice in the patients who have high suspicion for MG but normal conventional RNS.     

Suicidal ideation and suicide attempts among diabetes mellitus: The Korea National Health and Nutrition Examination Survey (KNHANES IV,V) from 2007 to 2012

ObjectiveThe present study evaluated the mental health of patients with diabetes mellitus (DM) in Korea and compared it with mental health in the general Korean population.MethodsAll data included in the final analyses were collected from 34,065 subjects (20 years of age or older) who participated in the 2007–2012 Korea National Health and Nutrition Examination Survey (KNHANES). The mental health of 3846 DM patients were compared with that of 30,219 controls.ResultsA depressed mood for 2 or more continuous weeks was reported by 13.6% of subjects with normal glucose tolerance (NGT), 14.3% of those with impaired glucose intolerance (IFG), and 17.6% of DM patients. Suicidal thoughts were reported by 15.3% of individuals with NGT, 15.6% of participants with IFG, and 17.6% of DM patients. Suicidal attempts were reported by 0.8% of people with NGT, 1.0% of those with IFG, and 1.3% of DM patients. In DM patients, the crude odds ratio (OR) for depressive mood was 1.376 (95% confidence interval [CI]: 1.258–1.504), the OR for suicidal ideation was 1.481 (95% CI: 1.361–1.611) and the OR for suicidal attempts was 1.413 (95% CI: 1.021–1.956). A multivariate analysis revealed that the ORs for depression, suicidal ideation, and suicidal attempts in DM patients were 1.178 (95% CI: 1.070–1.297), 1.152 (95% CI: 1.050–1.263), and 1.413 (95% CI: 1.021–1.956), respectively.ConclusionsThe present study found that DM was associated with a marked increase in suicidal behaviors.     

HTLV‐1–associated myelopathy/tropical spastic paraparesis and peripheral neuropathy following live‐donor renal transplantation

Introduction: Our aim in this study was to provide an updated literature review of electrodiagnostic testing in myasthenia gravis and Lambert–Eaton myasthenic syndrome. Methods: A systematic review of the recent literature was performed using the following key words: myasthenia gravis (MG); Lambert–Eaton myasthenic syndrome (LEMS); electromyography (EMG); repetitive nerve stimulation (RNS); single‐fiber electromyography (SFEMG); nerve conduction study; and normative values. Results: Several articles supported testing of facial, bulbar, and respiratory muscles in the diagnosis of neuromuscular junction (NMJ) disorders, including muscle‐specific kinase antibody (MuSK)‐seropositive MG. Several articles supported use of concentric needle EMG as an alternative to SFEMG jitter in disorders of neuromuscular transmission. A limited number of articles addressed measurement of area (vs. amplitude) decrement in RNS and decreasing the threshold of post‐exercise facilitation. Conclusions: Electrodiagnostic testing continues to be useful for diagnosis of MG and LEMS, although the quality of the evidence is not great. This literature review summarizes RNS and jitter measurement of facial and respiratory muscles and use of concentric needle EMG for SFEMG. Muscle Nerve 52:455–462, 2015     

Value of tongue biting in the differential diagnosis between epileptic seizures and syncope

BackgroundTongue biting (TB) may occur both in epileptic seizures and in syncope. A comprehensive search of the literature to determine the accuracy of this physical finding and its prevalence in epileptic seizures and syncope is still lacking.AimsTo undertake a systematic review and a meta-analysis of studies evaluating the prevalence of TB in patients with epileptic seizures and syncope, and to determine sensitivity, specificity and likelihood ratios (LR) of this physical finding.MethodStudies comparing the prevalence of TB in epileptic seizures and syncope were systematically searched. Prevalence of TB was analyzed calculating odds ratio (OR) with 95% confidence intervals (CIs). Sensitivity, specificity, positive and negative likelihood ratio (pLR, nLR) of TB were determined for each study and for the pooled results.ResultsTwo studies (75 epilepsy patients and 98 subjects with syncope) were included. There was a significantly higher prevalence of TB in patients with epileptic seizures (OR 12.26; 95% CI 3.99–37.69). Pooled accuracy measures of TB for the diagnosis of epileptic seizures were: sensitivity 33%, specificity 96%, pLR 8.167 (95% CI 2.969–22.461) and nLR 0.695 (95% CI 0.589–0.82).ConclusionsA pooled analysis of data from the literature shows that TB has great value in the differential diagnosis between epileptic seizures and syncope. Given a certain pre-test probability of seizures, the presence of TB greatly increases the chance that the patient had an epileptic seizure. Systematic reviews with pooled analyses (meta-analyses) of data from the literature allow an increase in statistical power and an improvement in precision, representing a useful tool to determine the accuracy of a certain physical finding in the differential diagnosis between seizures and other paroxysmal events.     

High false-positive rate of questionnaire-based restless legs syndrome diagnosis in multiple sclerosis

Background/ObjectivesRestless legs syndrome (RLS) is diagnosed by self-reported symptoms. Multiple sclerosis (MS) patients have disease-related symptoms which could mimic RLS. This study assessed the: (1) false-positive rate for questionnaire-based RLS diagnosis in MS patients and (2) utility of periodic leg movements during wakefulness (PLMW) on overnight polysomnography (PSG) in identifying true-positive RLS patients.MethodsAmbulatory MS patients without known sleep disorders were recruited. Subjects completed the International RLS Study Group (IRLSG) diagnostic questionnaire (IRLDQ) and underwent full overnight PSG. IRLDQ-positive patients underwent clinical evaluation to confirm the diagnosis and completed the RLS severity scale (IRLS).ResultsSeventy-one MS patients (mean age 46.8 ± 10.4 years) were evaluated. Thirty-eight had a positive IRLDQ. RLS diagnosis was confirmed in 22, yielding a false-positive rate of 42% [95% confidence interval (CI) 26–59%], predominantly attributable to paresthesiae (n = 7), and cramps and/or muscle spasms (n = 4). IRLS scores were not significantly different between subjects with confirmed and nonconfirmed RLS. The PLMW index was significantly higher in patients with confirmed RLS (55.4 ± 41.9 vs. 29.7 ± 18.8, p = 0.03). The sensitivity of a PLMW index >70/h for true-positive IRLDQ was 8/22 = 36%, 95% CI: 17.2–59.3, and the specificity was 16/16 = 100%, 95% CI: 79.4–100.ConclusionsMS patients have a high false-positive rate of RLS diagnosis using a standardized questionnaire largely attributable to MS-related sensorimotor symptoms. While detailed clinical evaluation is essential for confirming RLS diagnosis, the PLMW index may provide useful adjunctive information.