The Atypical “Diving” Lesion: Congenital Imperforate Submandibular Duct Neurographics
2020; 10 (2): 88 - 91
View details for DOI 10.3174/ng.1900033
- A Multimodal and Pathological Analysis of a Renal Cell Carcinoma Metastasis to the Thyroid Gland 11 Years Post Nephrectomy JOURNAL OF RADIOLOGY CASE REPORTS 2019; 13 (4): 1–9
Cerebral foreign body reaction due to hydrophilic polymer embolization following aneurysm treatment by pipeline flow diversion device.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
The use of flow diverting stents for wide based, intracranial aneurysms has become an invaluable treatment option. While intracranial hemorrhage and ischemic stroke from dislodged atherosclerotic emboli are common adverse events, the potential for delayed granulomatous inflammation from possible hydrophilic polymer emboli is rarely recognized. We present a unique case in which visible chipping of the pusher wire for stent placement was observed, followed by clinical and radiographic evidence suggestive of a delayed foreign body reaction to intracranial hydrophilic polymer emboli. A 55-year-old woman underwent placement of a Pipeline embolization device for a left-sided, broad-based aneurysm at the base of the internal carotid artery and posterior communicating artery. Two months later she developed right-sided focal neurological deficits. Imaging showed ipsilateral focal edema and enhancing lesions with contrast. Although not confirmed with biopsy and histopathology, clinical and radiographic evidence suggests that this patient probably experienced a delayed foreign body reaction to hydrophilic polymer emboli from compromised procedural equipment during flow diverting stent placement. Although previously described, this is the first instance to our knowledge in whichvisible chipping of the pusher wire was observed on a Pipeline embolization device.
View details for DOI 10.1177/1591019919830767
View details for PubMedID 30922199
Drooling in Parkinson's disease: A randomized controlled trial of incobotulinum toxin A and meta-analysis of Botulinum toxins
PARKINSONISM & RELATED DISORDERS
2016; 30: 73–77
Botulinum toxins are a therapeutic option for drooling in Parkinson's Disease (PD). The aims of this study were to: 1. evaluate the efficacy of incobotulinum toxin A for drooling in PD. 2. Perform a meta-analysis of studies of Botulinum toxins for drooling in PD.1. Primary study: Randomized, double blind, placebo controlled, cross over trial. Incobotulinum toxin (100 units) or saline was injected into the parotid (20 units) and submandibular (30 units) glands. Subjects returned monthly for three evaluations after each injection. Outcome measures were saliva weight and Drooling Frequency and Severity Scale. 2. Systematic review of literature, followed by inverse variance meta-analyses using random effects models.1. Primary Study: Nine of 10 subjects completed both arms. There was no significant change in the primary outcome of saliva weight one month after injection in the treatment period compared to placebo period (mean difference, gm ± SD: -0.194 ± 0.61, range: -1.28 to 0.97, 95% CI -0.71 to 0.32). Secondary outcomes also did not change. 2. Meta-analysis of six studies demonstrated significant benefit of Botulinum toxin on functional outcomes (effect size, Cohen's d: -1.32, CI -1.86 to -0.78). The other studies used a higher dose of Botulinum toxin A into the parotid glands.This study did not demonstrate efficacy of incobotulinum toxin A for drooling in PD, but lacked precision to exclude moderate benefit. The parotid/submandibular dose-ratio may have influenced results. Studies evaluating higher doses of incobotulinum toxin A into the parotid glands may be useful.
View details for DOI 10.1016/j.parkreldis.2016.07.001
View details for Web of Science ID 000383527200014
View details for PubMedID 27406786
Impedance Alterations in Healthy and Diseased Mice During Electrically Induced Muscle Contraction
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
2016; 63 (8): 1602–12
Alterations in the health of muscles can be evaluated through the use of electrical impedance myography (EIM). To date, however, nearly all work in this field has relied upon the measurement of muscle at rest. To provide an insight into the contractile mechanisms of healthy and disease muscle, we evaluated the alterations in the spectroscopic impedance behavior of muscle during the active process of muscle contraction. The gastrocnemii from a total of 13 mice were studied (five wild type, four muscular dystrophy animals, and four amyotrophic lateral sclerosis animals). Muscle contraction was induced via monophasic current pulse stimulation of the sciatic nerve. Simultaneously, multisine EIM (1 kHz to 1 MHz) and force measurements of the muscle were performed. Stimulation was applied at three different rates to produce mild, moderate, and strong contractions. We identified changes in both single and multifrequency data, as assessed by the Cole impedance model parameters. The processes of contraction and relaxation were clearly identified in the impedance spectra and quantified via derivative plots. Reductions in the center frequency fc were observed during the contraction consistent with the increasing muscle fiber diameter. Different EIM stimulation rate-dependencies were also detected across the three groups of animals.
View details for DOI 10.1109/TBME.2014.2320132
View details for Web of Science ID 000380325000005
View details for PubMedID 24800834
An improved electrical impedance myography (EIM) tongue array for use in clinical trials
2016; 127 (1): 932–35
Electrical impedance myography (EIM) measurements of the tongue could provide valuable information about bulbar dysfunction in amyotrophic lateral sclerosis (ALS). A prototype tongue depressor EIM array produced gag reflexes. The objectives of this study were to determine the reliability, mean phase values, and tolerability of tongue EIM measurements using a smaller electrode array.Tongue EIM measurements were performed in a total of 31 healthy individuals and four neuromuscular patients with lingual abnormalities. Reliability was assessed by calculating the intraclass correlation coefficient (ICC) and percent difference in addition to performing Bland-Altman analyses. Standard descriptive statistics, including results of a Mann-Whitney test, were also determined.At the 50 kHz frequency, the ICCs for intra- and inter-rater reliability were 0.76 with 5.17% difference and 0.78 with 5.34% difference respectively. The mean EIM phase values of healthy participants (11.61° ± 1.00°) and patients (9.87° ± 1.28°) were significantly different (p=0.0051). None of the participants experienced gag reflexes or discomfort.The small tongue array provided good inter- and intra-rater reliability, could preliminarily distinguish between healthy and diseased muscle, and was well-tolerated.Biomarker information about tongue health could be more comfortably obtained with a smaller EIM array.
View details for DOI 10.1016/j.clinph.2015.06.021
View details for Web of Science ID 000367540800115
View details for PubMedID 26242815
View details for PubMedCentralID PMC4698239
ASSESSMENT OF AGED mdx MICE BY ELECTRICAL IMPEDANCE MYOGRAPHY AND MAGNETIC RESONANCE IMAGING
MUSCLE & NERVE
2015; 52 (4): 598–604
Similar to magnetic resonance imaging (MRI), electrical impedance myography (EIM) is dependent on the presence and location of water in muscle to assess neuromuscular diseases. We compared the 2 technologies in mdx mice to better understand their relationship.EIM and MRI, using T2 relaxation and diffusion-weighted imaging (DWI), were performed on the gastrocnemius of 10 mdx and 10 wild-type mice. Muscle function and tissue composition measurements were compared with the EIM and MRI data.EIM reactance and T2 relaxation mapping can discriminate healthy from diseased mice (P < .001 for both), but DWI could not. Both T2 relaxation and EIM reactance also correlated closely with muscle function/composition and with each other.Given the low cost of EIM and the simplicity of application, it may be a valuable alternative to muscle MRI in Duchenne muscular dystrophy, where simple cumulative indices of muscle health are being sought.
View details for DOI 10.1002/mus.24573
View details for Web of Science ID 000362544400019
View details for PubMedID 25597760
Inter-session reliability of electrical impedance myography in children in a clinical trial setting
2015; 126 (9): 1790–96
High reliability is a prerequisite for any test to be useful as a biomarker in a clinical trial. Here we assessed the reproducibility of electrical impedance myography (EIM) in children by comparing data obtained by different evaluators on separate days.Healthy boys and boys with Duchenne muscular dystrophy (DMD) aged 2-14 years underwent EIM of multiple muscles performed by two evaluators on two visits separated by 3-7 days. Single and multifrequency data were analyzed. Reliability was assessed via calculation of the percent relative standard deviation (% RSD), Bland-Altman analysis, and the intraclass correlation coefficient (ICC).For both individual muscle data and data averaged across muscles, intra-evaluator measurements showed high repeatability for both 50 kHz phase and 50/200 kHz phase ratio values, with ICCs generally above 0.90 and % RSD below 10%. Inter-evaluator results showed very similar ICC and % RSD values as those obtained by the same evaluator.Both the 50 kHz phase and 50/200 kHz phase ratio are reliable measures both across time and evaluators and in both health and disease.These results support the concept that EIM can serve as a reliable measure in clinical therapeutic trials in a pediatric population.
View details for DOI 10.1016/j.clinph.2014.11.017
View details for Web of Science ID 000359319800022
View details for PubMedID 25533276
View details for PubMedCentralID PMC4447621
QUANTITATIVE MUSCLE ULTRASOUND IN DUCHENNE MUSCULAR DYSTROPHY: A COMPARISON OF TECHNIQUES
MUSCLE & NERVE
2015; 51 (2): 207–13
Muscle pathology in Duchenne muscular dystrophy (DMD) can be quantified using ultrasound by measuring either the amplitudes of sound-waves scattered back from the tissue [quantitative backscatter analysis (QBA)] or by measuring these backscattered amplitudes after compression into grayscale levels (GSL) obtained from the images.We measured and compared QBA and GSL from 6 muscles of 25 boys with DMD and 25 healthy subjects, aged 2-14 years, with age and, in DMD, with function (North Star Ambulatory Assessment).Both QBA and GSL were measured reliably (intraclass correlation ≥ 0.87) and were higher in DMD than controls (P < 0.0001). In DMD, average QBA and GSL measured from superficial regions of muscle increased (rho ≥ 0.47, P < 0.05) with both higher age and worse function; in contrast, GSL measured from whole regions of muscle did not.QBA and GSL measured from superficial regions of muscle can similarly quantify muscle pathology in DMD.
View details for DOI 10.1002/mus.24296
View details for Web of Science ID 000348426800008
View details for PubMedID 24862337
View details for PubMedCentralID PMC4241391
Optimizing electrical impedance myography measurements by using a multifrequency ratio: A study in Duchenne muscular dystrophy
2015; 126 (1): 202–8
Electrical impedance myography (EIM) is an electrophysiological technique for neuromuscular evaluation that is impacted by subcutaneous fat (SF). Exploiting the differing frequency dependences of muscle and fat, we assessed a 2-frequency EIM phase ratio in Duchenne muscular dystrophy (DMD) boys.Twenty-eight DMD boys aged 2-13years underwent EIM and the 6-minute walk test (6MWT). For each subject, 50kHz phase data was input into the numerator while 20-500kHz phase values were input into the denominator. We then performed correlation analyses seeking to identify the denominator frequency that simultaneously optimized SF and 6MWT correlations. This optimized ratio was then tested in 24 healthy boys.50kHz phase correlated to 6MWT in DMD boys with R=0.52, p=0.0066, and to SF thickness with R=-0.67, p<0.001. An optimized ratio of 50/200kHz phase reduced the correlation of SF thickness to R=-0.075, p=0.45 while improving the relationship to the 6MWT (R=0.60, p=0.001). In normal subjects, the optimization decreased SF correlation from R=0.61 from R=0.16 with 6MWT correlation remaining unchanged.The 50/200kHz EIM phase ratio removes the impact of SF while maintaining EIM's association with function.The use of a phase ratio may enhance EIM's application for evaluation of neuromuscular disease.
View details for DOI 10.1016/j.clinph.2014.05.007
View details for Web of Science ID 000348561800028
View details for PubMedID 24929900
View details for PubMedCentralID PMC4234696
Cross-sectional Evaluation of Electrical Impedance Myography and Quantitative Ultrasound for the Assessment of Duchenne Muscular Dystrophy in a Clinical Trial Setting
2014; 51 (1): 88–92
Electrical impedance myography and quantitative ultrasound are two noninvasive, painless, and effort-independent approaches for assessing neuromuscular disease. Both techniques have potential to serve as useful biomarkers in clinical trials in Duchenne muscular dystrophy. However, their comparative sensitivity to disease status and how they relate to one another are unknown.We performed a cross-sectional analysis of electrical impedance myography and quantitative ultrasound in 24 healthy boys and 24 with Duchenne muscular dystrophy, aged 2 to 14 years with trained research assistants performing all measurements. Three upper and three lower extremity muscles were studied unilaterally in each child, and the data averaged for each individual.Both electrical impedance myography and quantitative ultrasound differentiated healthy boys from those with Duchenne muscular dystrophy (P < 0.001 for both). Quantitative ultrasound values correlated with age in Duchenne muscular dystrophy boys (rho = 0.45; P = 0.029), whereas electrical impedance myography did not (rho = -0.31; P = 0.14). However, electrical impedance myography phase correlated with age in healthy boys (rho = 0.51; P = 0.012), whereas quantitative ultrasound did not (rho = -0.021; P = 0.92). In Duchenne muscular dystrophy boys, electrical impedance myography phase correlated with the North Star Ambulatory Assessment (rho = 0.65; P = 0.022); quantitative ultrasound revealed a near-significant association (rho = -0.56; P = 0.060). The two technologies trended toward a moderate correlation with one another in the Duchenne muscular dystrophy cohort but not in the healthy group (rho = -0.40; P = 0.054 and rho = -0.32; P = 0.13, respectively).Electrical impedance myography and quantitative ultrasound are complementary modalities for the assessment of boys with Duchenne muscular dystrophy; further study and application of these two modalities alone or in combination in a longitudinal fashion are warranted.
View details for DOI 10.1016/j.pediatrneurol.2014.02.015
View details for Web of Science ID 000338174800016
View details for PubMedID 24814059
View details for PubMedCentralID PMC4063877
ELECTRICAL IMPEDANCE MYOGRAPHY FOR THE IN VIVO AND EX VIVO ASSESSMENT OF MUSCULAR DYSTROPHY ( mdx) MOUSE MUSCLE
MUSCLE & NERVE
2014; 49 (6): 829–35
Sensitive, non-invasive techniques are needed that can provide biomarkers of disease status and the effects of therapy in muscular dystrophy.We evaluated electrical impedance myography (EIM) to serve in this role by studying 2-month-old and 18-month-old mdx and wild-type (WT) animals (10 animals in each of 4 groups).Marked differences were observed in EIM values between mdx and WT animals; the differences were more pronounced between the older age groups (e.g., reactance of 92.6 ± 4.3 Ω for mdx animals vs. 130 ± 4.1 Ω for WT animals, P<0.001). In addition, in vivo EIM parameters correlated significantly with the extent of connective tissue deposition in the mdx animals.EIM has the potential to serve as a valuable non-invasive method for evaluating muscular dystrophy. It can be a useful biomarker to assist with therapeutic testing in both pre-clinical and clinical studies.
View details for DOI 10.1002/mus.24086
View details for Web of Science ID 000335954400007
View details for PubMedID 24752469
View details for PubMedCentralID PMC5582805
A pilot spectroscopy study on time-varying bioimpedance during electrically-induced muscle contraction
IEEE. 2014: 3739–42
Alterations in the health of muscles can be evaluated through the use of electrical impedance myography (EIM). To date, however, nearly all work has relied upon single-frequency/spectroscopy stepped-sine measurements of static muscle (contracted or relaxed). In this work, we assessed the temporal alterations in the impedance spectrum (1 kHz to 1 MHz) behavior of gastrocnemius during the active process of muscle contraction. The approach is based on the multisine impedance spectroscopy technique. The gastrocnemii of a wild type mouse was measured during electrically-induced muscle contraction via direct current stimulation of the sciatic nerve. The processes of contraction and relaxation were clearly identified in the time-frequency impedance spectrum likely corresponding to an increase muscle fiber diameter. The technique of dynamic multisine EIM has the potential of providing useful insights into contractile mechanisms of muscle in health and disease.
View details for Web of Science ID 000350044703181
View details for PubMedID 25570804
Age- and gender-associated differences in electrical impedance values of skeletal muscle
2013; 34 (12): 1611–22
Electrical impedance measurements of skeletal muscle may be sensitive to age-associated declines in muscle health. In an effort to evaluate this concept further, we performed electrical impedance myography (EIM) using a handheld array on 38 individuals aged 19-50 years and 41 individuals aged 60-85 years. Individuals either had seven upper extremity or seven lower extremity muscles measured. The 50 kHz reactance, resistance and phase were used as the major outcome variables. Although the phase values were similar in both groups, both reactance and resistance values were lower in the lower extremities of the older individuals as compared to the younger (-23 ± 6%, p = 0.001 for reactance and -27 ± 7%, p = 0.005 for resistance), whereas changes in upper extremity values were not significantly different (-9 ± 5%, p = 0.096 for reactance and +5 ± 9%, p = 0.55 for resistance). When analyzing the genders separately, it became clear that this reduction in lower extremity values was most pronounced in men and less consistently present in women. These findings suggest that age- and gender-associated differences in muscle condition are detectable using EIM. The relationship of these easily obtained parameters to standard functional, imaging, and pathological markers of sarcopenia deserves further study.
View details for DOI 10.1088/0967-3334/34/12/1611
View details for Web of Science ID 000328894200003
View details for PubMedID 24165434
View details for PubMedCentralID PMC3895401