The Sensitivity and Specificity of Split-Hand Index Using Muscle Sonography.

BACKGROUND: The split-hand index (SHI) (first dorsal interosseous (FDI) × abductor pollicis brevis (APB)/abductor digiti minimi muscle (ADM)) has been suggested as a useful measure for amyotrophic lateral sclerosis (ALS) diagnosis, using electrophysiological and sonographic indices. In the present study, we aimed to explore the specificity of SHI derived by muscle ultrasound (MUS) for the diagnosis of ALS and spinal muscular atrophy (SMA). METHODS: Healthy controls (n = 65) were prospectively recruited at the Prosserman Family Neuromuscular clinic at Toronto General Hospital, from October to December 2018. In addition, 181 patients with ALS (n = 91), SMA (n = 33), polyneuropathy (n = 35), and myopathy (n = 22) were prospectively recruited at the neuromuscular clinic at Tel Aviv Sourasky Medical Center, from December 2018 to December 2020. All subjects underwent quantitative sonographic evaluation of muscle thickness, including the right APB, FDI, and ADM muscles. Area under curve (AUC), sensitivity, and specificity were determined for differentiating between groups. RESULTS: Although SHI showed good to excellent accuracy for differentiating each patient subgroup from controls (AUC 0.83-0.92), poorer diagnostic accuracy was shown for differentiating between different patient subgroups (AUC 0.54-0.74). CONCLUSIONS: Sonographic SHI is useful for differentiating patients from healthy controls, but might be not specific for motor neuron disease.

Pre-morbid Laboratory Tests, Diseases, and Medications in Amyotrophic Lateral Sclerosis in Israel.

BACKGROUND: There is an unmet need for real-world data regarding laboratory results, co-morbidities, and medication use prior to the first symptoms of amyotrophic lateral sclerosis (ALS). Researchers must identify specific subpopulations at risk for developing ALS and understand pathogenic mechanisms preceding the clinical presentation of ALS as well as possible subclinical disease manifestations. OBJECTIVES: To valuate the role of laboratory results, co-morbidities, and medication use prior to the first symptoms of patients with ALS in Israel so that specific subpopulations at risk for developing ALS can be identified and for possible subclinical disease manifestations. To understand pathogenic mechanisms preceding the clinical presentation of ALS. METHODS: At the ALS clinic at Tel Aviv Sourasky Medical Center, 259 ALS patients insured by Maccabi Healthcare Services and seen between January 1998 and December 2017 were included. Comparisons of demographics, co-morbidities, medications taken, history of trauma, and laboratory tests prior to disease onset were performed between patients and 1295 matched controls. RESULTS: Prior to disease presentation, ALS patients had a higher frequency of hypertension and cardiovascular disease; presented more frequently with trauma and viral infections; more frequently used analgesics, non-steroidal anti-inflammatory drugs, narcotics, antibiotics, and antiviral medications; and had higher creatine kinase levels. CONCLUSIONS: ALS patients showed higher frequency of cardiovascular disease prior to diagnosis, as well as higher frequency of trauma, infections, and pain medication usage.

The complex association between pain and neuropathy.

BACKGROUND: Several studies of patients with polyneuropathy failed to show differences between patients with and without pain. In the current study, we aimed to explore the association between neuropathic symptoms, mainly pain, and polyneuropathy characteristics. METHODS: A prospective cross-sectional study recruiting 151 patients with non-diabetic polyneuropathy was performed between November 2016 and May 2017. A total of 38 patients with chronic inflammatory demyelinating neuropathy were excluded. Patients underwent clinical, electrophysiological and functional assessments of their polyneuropathy. Polyneuropathy characteristics were compared depending on the presence and severity of neuropathic symptoms. RESULTS: The presence and the severity of weakness were associated with a more severe neuropathy as measured by clinical, electrophysiological and functional assessments, while the presence of pain was associated with higher sural amplitudes, and the severity of pain showed a curvilinear association with neuropathy severity. CONCLUSIONS: Our study shows a novel finding of a curvilinear association between pain and polyneuropathy severity.

Fasciculation frequency at the biceps brachii and brachialis muscles is associated with amyotrophic lateral sclerosis disease burden and activity.

INTRODUCTION: Fasciculations are most commonly seen in the biceps brachii muscle in amyotrophic lateral sclerosis (ALS). In this study we have explored the association between fasciculation frequency in a single location-biceps brachii and brachialis muscles (BB), and disease burden and activity. METHODS: Sonographic muscle studies were performed in 90 ALS patients, 47 of whom were seen in subsequent follow-up. The association between fasciculations frequency at the BB and ALS Functional Rating Scale-Revised (ALSFRS-R) and manual muscle testing (MMT) scores was determined. RESULTS: High fasciculation frequency at the BB, where detection rate was the highest, was associated with shorter disease duration, greater muscle thickness, higher MMT scores, and faster rate of decline in ALSFRS-R initially, and MMT subsequently. DISCUSSION: High fasciculation frequency at the BB as determined by sonography, is associated with less impairment at time of examination, and a more active disease with a more rapid progression.

The utility of a single simple question in the evaluation of patients with nondiabetic polyneuropathy.

INTRODUCTION: A single and simple question, namely "What percentage of normal (PoNL) do you feel regarding your disease?" is feasible and valid in myasthenia gravis. In this study, we aimed to determine the validity of this question in patients with nondiabetic polyneuropathy. METHODS: Clinical, electrophysiological, and functional and disability assessments were performed in 151 patients with nondiabetic polyneuropathy. One hundred forty patient answers were recorded for the PoNL question, and these were included in the current study. RESULTS: The PoNL correlated moderately with functional and disability scales. DISCUSSION: "What PoNL do you feel?" is a simple, quick, and valid question, which correlates moderately with functional and disability scales in nondiabetic polyneuropathy, and it may be incorporated in polyneuropathy assessment.

Quantitative sonographic evaluation of muscle thickness and fasciculation prevalence in healthy subjects.

BACKGROUND: In the current study, we aimed to determine normative values for muscle thickness and fasciculation prevalence in healthy subjects. METHODS: We performed a prospective study from October to December 2018 in 65 healthy subjects. All subjects underwent quantitative sonographic evaluation of muscle thickness and fasciculation prevalence in the following 8 muscles: Biceps brachii, abductor pollicis brevis, first dorsal interosseous, abductor digiti minimi, quadriceps, tibialis anterior, extensor digitorum brevis, and abductor hallucis brevis. RESULTS: Subject ages ranged from 21 to 82 years, with 63% women. Normative values for muscle thickness were determined using the fifth percentile. Multivariate regression analysis showed that sex, age, body mass index, and hand dominance affected muscle thickness. Fasciculations were observed frequently only in distal muscles. CONCLUSIONS: Normal values for muscle thickness were determined, and may enhance neuromuscular ultrasound sensitivity and serve as a basis for future studies. Larger series are needed to confirm these values.

Prospective study of stress, depression and personality in myasthenia gravis relapses.

BACKGROUND: Psychopathology and personality traits may influence the course of autoimmune disorders. With this prospective longitudinal cohort study, we aimed to assess personality, stress and depression in myasthenia patients who relapse and those who remain stable or improve (non-relapsers). METHOD: We collected data from 155 consecutive adult patients with confirmed MG attending the Neuromuscular Clinic, Toronto General Hospital, between March 2017 and July 2018, for this study. Patients were assessed at baseline and 6 months, or at the time of MG relapse. At both visits, the patients were assessed clinically and were asked to complete self-administered questionnaires for disease severity, chronic stress and depression. Personality type was assessed at baseline only. Relapsing patients were defined as those patients with MGII score increasing by more than 5.5 points from visit 1 to visit 2. RESULTS: Relapsers had higher baseline scores for depression (p = 0.01) and the change in disease severity correlated with the change in depression score (r = 0.2534, p = 0.0015, 95% CI: 0.098 0.3961). Higher levels of stress at baseline and neuroticism predicted higher relapse rates (p = 0.01 and p < .0001, respectively). In the linear regression model, with change of the MGII score as the dependent variable, change in depression scores (p = 0.0004) and age (p = 0.03) predicted change in disease severity. CONCLUSIONS: Since emotional factors and personality type may influence MG, attention to these factors might improve care in MG patients.

European Federation of Neurological Societies cutoff values significantly reduce creatine kinase sensitivity for diagnosing neuromuscular disorders.

INTRODUCTION: Elevated creatine kinase (CK) level was redefined by the European Federation of Neurological Societies)EFNS(as 1.5 times the upper limit of normal. In the current study we sought to determine the sensitivity and specificity of CK testing for the diagnosis of neuromuscular disorders. METHODS: Demographics and CK levels were retrospectively extracted from an electronic database for 234 patients with neuromuscular disorders. Sensitivity, specificity, and likelihood ratios and the area under curve were determined for each diagnosis and different cutoff CK values. RESULTS: Using the EFNS cutoff values significantly reduced CK test sensitivity. Creatine kinase values >1000 IU/L showed a high likelihood (11.04) for myopathies and a low likelihood for polyneuropathies (0). DISCUSSION: European Federation of Neurological Societies cutoff values significantly reduce CK sensitivity for diagnosing neuromuscular disorders. While low CK values cannot exclude a neuromuscular disease, values >1000 IU/L are associated with a high likelihood of myopathy.

Muscle thickness measured by ultrasound is reduced in neuromuscular disorders and correlates with clinical and electrophysiological findings.

INTRODUCTION: Nerve imaging has a limited role in axonal and muscle fiber loss. In this study, we sought to explore the utility of standardized muscle ultrasound (US) assessment in these clinical scenarios. METHODS: We performed a prospective study from March to August 2018 of patients attending the neuromuscular clinic. All patients underwent clinical evaluation and standardized muscle thickness measurement by US in seven muscles. RESULTS: The study cohort consisted of 114 participants, including patients with polyneuropathy, motor neuron disease, and myopathy. The smallest distal muscle thickness was found in patients with polyneuropathy, while the smallest proximal muscle thickness was found in patients with myopathy. Muscle thickness was strongly correlated with muscle strength (r 2 = 0.62), electrophysiological findings (r 2 : 0.44-0.55), and disability score (r 2 = 0.53). DISCUSSION: Standardized muscle thickness measured by US shows diagnostic usefulness in a spectrum of neuromuscular disorders and correlates with clinical and electrophysiological findings.

Evidence of small-fiber neuropathy in neurofibromatosis type 1.

INTRODUCTION: Large-fiber neuropathy is rare in neurofibromatosis type 1, but small-fiber neuropathy has not been studied. METHODS: Patients with neurofibromatosis type 1 underwent nerve conduction studies for large-fiber assessment. Small-fiber tests included quantitative thermal thresholds, laser Doppler flare imaging, intraepidermal nerve fiber density, and corneal nerve fiber length. RESULTS: Of the 52 patients enrolled, 31 (60%) were female and the mean age was 33.0 ± 12.3 years. Four (8%) patients had abnormal nerve conduction studies. Small-fiber tests were frequently abnormal: thermal thresholds in 7 (13%); laser Doppler flare imaging in 10 (19%); intraepidermal nerve fiber density in 11 (22%); and corneal nerve fiber length in 27 (52%). The mean corneal nerve fiber length was below normative level (10.1 ± 2.7 mm/mm3 ). DISCUSSION: Small-fiber neuropathy may be common in neurofibromatosis type 1, and should be investigated in symptomatic patients.

Baseline Decrement in Patients with Mild Myasthenia Gravis Predicts Immunomodulation Treatment.

To explore whether higher degrees of electrophysiological abnormalities are associated with a more frequent exposure to a more aggressive treatment regimen, we performed a retrospective chart review of patients attending the neuromuscular clinic from June 2012 to December 2015 and included 87 patients. We compared treatment regimens during the follow-up period between patients with high and low jitter and decrement. Myasthenia gravis patients with high jitter or decrement at baseline were more frequently treated with intravenous immunoglobulins (IVIG) and/or plasma exchange (PLEX) during the follow-up period. In patients with mild disease, IVIG or PLEX treatment was associated with high decrement.

La diminution initiale du potentiel moteur de patients atteints de myasthénie grave peut permettre de prédire le type d'immuno-modulation thérapeutique prodiguée. Afin d'explorer dans quelle mesure des niveaux plus élevés d'anomalies électro-physiologiques peuvent être associés à une exposition davantage fréquente à des régimes de traitement plus vigoureux, nous avons effectué un examen rétrospectif des dossiers de patients, 87 au total, s'étant présentés à une clinique neuromusculaire de juin 2012 à décembre 2015. Nous avons alors comparé les régimes de traitement des patients montrant de basses mesures de gigue (jitter) et une faible diminution d'amplitude du potentiel d'action au cours de leur période de suivi avec les régimes de traitement d'autres patients pour qui ces mesures étaient élevées. Les patients atteints de myasthénie grave (MG) dont les mesures de gigue et la diminution d'amplitude du potentiel d'action étaient initialement élevées ont été plus fréquemment traités, lors d'un suivi, avec des immunoglobulines intraveineuses et/ou des échanges plasmatiques. Chez les patients atteints de la forme bénigne de cette maladie, ces deux traitements ont été associés à une diminution d'amplitude du potentiel d'action plus élevée.

Uric Acid Levels Correlate with Sensory Nerve Function in Healthy Subjects.

BACKGROUND: High levels of uric acid (UA) are associated with various peripheral neuropathies. Furthermore, uric acid levels have been found to correlate with both the clinical and electrophysiological severity of diabetic sensorimotor polyneuropathy, mainly with sensory functions. OBJECTIVES: To determine whether higher UA levels are associated negatively with nerve function in healthy subjects. METHODS: A total of 126 healthy subjects recruited prospectively for another study were included. We extracted demographic data, body mass index (BMI), blood pressure, Toronto Clinical Neuropathy Score (TCNS), electrophysiological findings, vibration perception thresholds (VPT), and laboratory test results including UA, hemoglobin A1c (HbA1c), estimated glomerular filtration rate (eGFR), and lipid levels. RESULTS: The mean age of the cohort was 56 ± 17 years with 56% females. Males had higher UA values compared with females. Univariate beta regression coefficient analysis between UA levels and demographic, clinical, electrophysiological, and laboratory findings showed significant positive correlations with male gender, components of the metabolic syndrome, and with VPT, while an inverse correlation was found with electrophysiological sensory parameters. A multivariate regression model showed positive correlations only with BMI, finger VPT, and triglycerides. CONCLUSION: Higher UA levels correlate with lower sensory nerve function in healthy subjects, expanding the evidence of possible negative influence of UA on peripheral nerves, although a causative role has not yet established.

Ultrasound-Assisted Lumbar Puncture in a Neuromuscular Clinic has a High Success Rate and Less Pain.

BACKGROUND: Lumbar puncture (LP) performed with the assistance of ultrasound (US) may improve success rate, with fewer puncture attempts and less pain. OBJECTIVES: To explore the utility of US-assisted LP in a neuromuscular clinic. METHODS: We performed a prospective, randomized, open-label study between May 2016 and January 2017. The primary outcome measure was LP success rate, and the secondary outcome measures included procedure time, number of attempts, and the levels of pain, anxiety, and satisfaction. RESULTS: Lumbar puncture was performed in 40 consecutive patients. Ultrasound-assisted LP had a 100% success rate, compared with 85% (95% confidence interval: 58%-96%) without US assistance, although this difference failed to reach statistical significance. Ultrasound-assisted LP was associated with less pain and, also in patients >60 years of age, with fewer needle insertions. Both groups reported high satisfaction rates, regardless of the use of US. CONCLUSION: Ultrasound-assisted LP has a high success rate and less pain than unassisted LP, and can be accomplished easily in the outpatient neuromuscular clinic setting equipped with US.

CONTEXTE: En plus de diminuer le nombre de tentatives de ponction alors nécessaires et la douleur qui en résulte, il est possible qu'un examen de ponction lombaire effectué avec l'aide d'appareils à ultrasons obtienne un plus haut taux de réussite. OBJECTIFS: Dans le cadre d'une clinique neuromusculaire, se pencher sur l'utilité des examens de ponction lombaire assistés par des appareils à ultrasons. MÉTHODES: De mai 2016 à janvier 2017, nous avons mené une étude prospective sans insu à répartition aléatoire. La principale mesure de nos résultats a porté sur le taux de succès des examens de ponction lombaire. D'autres mesures de résultats ont inclus les aspects suivants: la durée des examens, le nombre de tentatives de ponction ainsi que les niveaux de douleur, d'anxiété et de satisfaction des patients. RÉSULTATS: Des examens de ponction lombaire ont été effectués chez 40 patients consécutifs. Ceux menés à l'aide d'appareils à ultrasons ont donné à voir un taux de succès de 100 % comparativement à 85 % (IC 95 % : 58 % - 96 %) dans le cas de ceux effectués sans ces appareils. Rappelons toutefois que cette différence ne s'est pas révélée significative sur le plan statistique. Les examens de ponction lombaire au moyen d'appareils à ultrasons ont aussi été associés à moins de douleurs ressenties et, chez des patients âgés de plus de 60 ans, à moins d'insertions d'aiguilles. Enfin, ces deux groupes ont rapporté des taux de satisfaction élevés, et ce, sans égard à l'utilisation d'appareils à ultrasons. CONCLUSIONS: Les examens de ponction lombaire assistés par des appareils à ultrasons possèdent un haut taux de succès et entraînent moins de douleurs que ceux menés sans ces appareils. Ils peuvent aussi être effectués facilement dans le cadre de cliniques neuromusculaires externes qui en sont munies.

Quantitative sonographic assessment of myotonia.

INTRODUCTION: This study explores ultrasound imaging for qualitative and quantitative assessment of myotonia. METHODS: Sixteen patients with myotonia and 16 controls underwent sonographic evaluation of the thenar eminence muscles to assess the relaxation time after muscle percussion. RESULTS: The mean time for complete muscle relaxation in patients with myotonia was longer than that of controls. A cutoff of > 0.9 s for myotonia detection had a sensitivity of 88% and a specificity of 100%. The interrater reliability was moderate for qualitative assessment but was high for quantitative assessment. The relaxation time did not correlate with the number of trinucleotide repeats in patients with myotonic dystrophy. DISCUSSION: Sonographic evaluation for the presence of myotonia is feasible, sensitive, and specific but does not correlate with disease severity in myotonic dystrophy. Muscle Nerve 57: 146-149, 2018.

The utility of a single simple question in the evaluation of patients with myasthenia gravis.

INTRODUCTION: Assessing myasthenia gravis (MG) can be challenging, and multiple scales are available to evaluate disease severity. We evaluated the utility of a single, simple question, as part of the MG evaluation: "What percentage of normal do you feel regarding your MG, 0%-100% normal?" METHODS: A retrospective chart review of patients attending the neuromuscular clinic from January 2014 to December 2015 was performed. Responses were correlated with symptoms and signs, the Quantitative Myasthenia Gravis Score (QMGS), the Myasthenia Gravis Impairment Index (MGII), and the 15-item Myasthenia Gravis Quality of Life scale (MG-QOL15). RESULTS: The total cohort included 169 patients. The percentage of normal correlated strongly with limb muscle weakness and MG scales, moderately with bulbar and respiratory symptoms, and weakly with ocular manifestations. DISCUSSION: The question, "What percentage of normal do you feel regarding your MG?" is feasible and valid, and can be incorporated easily into routine clinical evaluation. Muscle Nerve 57: 240-244, 2018.

High frequency of MGUS in DSP.

INTRODUCTION: Monoclonal gammopathy has been reported in several polyneuropathies. In this study, we sought to explore the frequency and characteristics of monoclonal gammopathy in patients with diabetic sensorimotor polyneuropathy (DSP). METHODS: Patients with type 1 and type 2 diabetes mellitus (DM 1, DM 2) and controls without diabetes were evaluated between November 2008 and December 2013. RESULTS: Fifty controls, 66 patients with DM 1, and 106 patients with DM 2 were included, with average ages of 43 ± 18, 45 ± 17, and 65 ± 10 years, respectively; the frequency of monoclonal gammopathy was 0%, 8%, and 15%, respectively. In patients with DSP, the frequency of monoclonal gammopathy increased to 14% in DM 1 and 21% in DM 2; the most common monoclonal proteins were immunoglobulin (Ig) M and IgG, respectively. DISCUSSION: DSP might be associated with a high frequency of monoclonal gammopathy, with different characteristics in DM 1 and in DM 2. Muscle Nerve 57: 1018-1021, 2018.

Laboratory Abnormalities in Polyneuropathy and Electrophysiological Correlations.

To study the frequency of laboratory test abnormalities, and electrophysiological correlations, we performed a retrospective chart review of 226 patients with polyneuropathy. The frequency of laboratory test abnormalities, and correlations with electrophysiological findings were explored. Abnormal glucose handling tests were the most common findings (54%), followed by paraproteinemia (21%) and anemia (21%). The frequencies of paraproteinemia and anemia in our cohort were significantly higher than previously reported. In addition, several laboratory abnormalities correlated with electrophysiological findings of median neuropathy at the wrist, expanding current knowledge about the deleterious effects of various metabolic and hematologic derangements at this site.

Stroke and seizure continue to be the major brunt of in patient neurology care. An observation from teaching hospital.

OBJECTIVE: To assess the burden and describe the pattern of neurological disorders requiring admissions in a teaching hospital of Al Khobar. METHODS: This is a retrospective, cross sectional study, carried out in the Neurology Department of King Fahd Hospital of the University from January 2009 to December 2016. Neurological disorders were grouped as ischemic stroke, intracerebral hemorrhage, transient ischemic attack, cerebral venous sinus thrombosis, seizure disorders, central nervous system infection, multiple sclerosis, neuropathies, myopathies, headache, dementia and miscellaneous group. Data was entered and analyzed by Statistical Package for the Social Science (SPSS) version 22.0 (IBM Corp., Armonk, NY, USA). RESULTS: The records of 1,317 patients admitted under Neurology Service were analyzed. Out of that, 740 (56.2%) were male and 577 (43.8%) were female. Mean age was 46.9+\-24 years (mean+\-standard deviation). Ischemic stroke was the most common diagnosis (32%) followed by seizures (20%). Multiple sclerosis accounted for around 8% and central nervous system infections 5% of neurological admission. CONCLUSION: Ischemic stroke was found to be the most common etiology for hospitalization in our study. The results of our study are similar to previous literature. An urgent need to control major risk factors such as diabetes and hypertension is warranted to minimize the burden of stroke.

Repetitive nerve stimulation cutoff values for the diagnosis of myasthenia gravis.

INTRODUCTION: Repetitive nerve stimulation (RNS) showing ≥ 10% decrement is considered the cutoff for myasthenia gravis (MG), but this has never been validated. The objective of this study was to find an optimal validated cutoff value for decrement on RNS. METHODS: We performed retrospective chart review of patients who had electrophysiological assessment for possible MG from 2013 to 2015. RESULTS: A total of 122 patients with MG and 182 controls were identified. RNS sensitivities for generalized and ocular MG using the traditional ≥10% cutoff value were 46% and 15%, respectively, for frontalis recordings, and 35% and 19%, respectively, for nasalis recordings. Using a decrement cutoff value of 7% for frontalis and 8% for nasalis increased the sensitivities by 6-11%, with specificities of 95-96%. CONCLUSIONS: For RNS in facial muscles, we suggest a cutoff value of 7-8%, which increases test sensitivity by 6-11%, while preserving high specificity for the diagnosis of MG. Muscle Nerve, 2016 Muscle Nerve 55: 166-170, 2017.

Electrophysiological testing is correlated with myasthenia gravis severity.

INTRODUCTION: Electrophysiological studies play an important role in the diagnosis of myasthenia gravis (MG). The objectives of this study was to explore the correlation of jitter and decrement with various clinical symptoms and signs and disease severity. METHODS: We performed a retrospective chart review of 75 MG patients who attended the neuromuscular clinic from April 2013 to May 2014. We compared clinical characteristics between patients with high jitter (>100 µs) and decrement (>10%), and patients with lower values to explore the correlations and optimal thresholds of jitter and decrement for different clinical features. RESULTS: High jitter and decrement values were associated with more severe disease, manifested by more frequent symptomatic bulbar and limb muscle weakness, more frequent ocular and limb muscle weakness on examination, higher quantitative MG score, and generalized disease. CONCLUSIONS: The yield of the electrophysiological assessment in MG extends beyond disease diagnosis and correlates with disease severity and the presence of generalized disease. Muscle Nerve 56: 445-448, 2017.