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Entezari-Taher M, Singleton JR, Jones CR, Meekins G, Petajan JH, Smith AG. Changes in excitability of motor cortical circuitry in primary restless legs syndrome. Neurology 1999; 53:1201-5. [PMID: 10522873 DOI: 10.1212/wnl.53.6.1201] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To investigate the excitability of segmental and suprasegmental systems in patients with primary restless legs syndrome (pRLS) by measuring the cortical silent period (C-SP) and the peripheral silent period (P-SP). BACKGROUND There is some evidence that RLS may be the motor manifestation of normal CNS periodicity that becomes disinhibited under certain conditions. The mechanism of this disinhibition is unclear. DESIGN/METHODS Ten patients with pRLS and 10 normal age-matched subjects were studied. The mixed nerve P-SP produced by electrical stimulation of the median and common peroneal nerves was recorded during maximal contraction of the abductor pollicis brevis (APB) and tibialis anterior (TA) muscles. The C-SP produced by a single magnetic shock to motor cortex at 150% of resting threshold was also measured during maximal contraction of the APB and TA muscles. The average of 5 to 10 trials at each site was obtained and compared using Student's t-test. RESULTS Resting central motor threshold was not significantly different between pRLS patients and the control group. The average duration of the C-SP was shorter in the APB (74.5+/-37.7 versus 129.56+/-35.95 msec, p<0.05) and TA (66.81+/-25.63 versus 136.1+/-40.35 msec, p<0.05) in patients with pRLS. The P-SP duration, however, was not significantly different between two groups in either limb. CONCLUSION The supraspinal inhibitory system is impaired in pRLS.
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26 |
76 |
2
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Smith R, Pioro E, Myers K, Sirdofsky M, Goslin K, Meekins G, Yu H, Wymer J, Cudkowicz M, Macklin EA, Schoenfeld D, Pattee G. Enhanced Bulbar Function in Amyotrophic Lateral Sclerosis: The Nuedexta Treatment Trial. Neurotherapeutics 2017; 14:762-772. [PMID: 28070747 PMCID: PMC5509619 DOI: 10.1007/s13311-016-0508-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The goal of this randomized, blinded, crossover clinical trial was to determine whether Nuedexta (dextromethorphan and quinidine) enhanced speech, swallowing, and salivation in patients with ALS. Sixty patients with amyotrophic lateral sclerosis (ALS) received either Nuedexta or placebo for 28 to 30 days, followed by a 10 to 15-day washout period. Subsequently, patients were switched to the opposite treatment arm for the remaining days of the trial. The primary endpoint was a reduction in the self-report Center for Neurologic Study Bulbar Function Scale (CNS-BFS) score. The rater-administered ALS Functional Rating Scale Revised was the principal secondary endpoint. The CNS-BFS score improved with active treatment, decreasing from a mean of 59.3 in the placebo arm of the trial to 53.5 during the drug-treatment arm (p < 0.001). Each of the individual domains of bulbar function interrogated by the CNS-BFS responded to treatment with Nuedexta as follows: salivation: 15.8 versus 14.3 (p = 0.004); speech: 24.6 versus 22.2 (p = 0.003); swallowing: 18.9 versus 17.1 (p = 0.009). Similarly, the bulbar component of the ALS Functional Rating Scale Revised improved with active treatment (p = 0.003), although the drug did not affect the motor and respiratory components of this scale. This study is unique for several reasons. Firstly, it was driven by patient reports of improved speech and swallowing while taking Nuedexta for control of emotional lability. Secondly, the study was conducted over a short duration (70 days), and thirdly, a self-report scale was selected as the principle outcome measure. Considering the importance of bulbar functions, these results, if confirmed, point to an additional use of Nuedexta as an adjunct to the management of ALS.
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Clinical Trial, Phase II |
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66 |
3
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Legon W, Adams S, Bansal P, Patel PD, Hobbs L, Ai L, Mueller JK, Meekins G, Gillick BT. A retrospective qualitative report of symptoms and safety from transcranial focused ultrasound for neuromodulation in humans. Sci Rep 2020; 10:5573. [PMID: 32221350 PMCID: PMC7101402 DOI: 10.1038/s41598-020-62265-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/04/2020] [Indexed: 02/08/2023] Open
Abstract
Low intensity transcranial focused ultrasound (LIFU) is a promising method of non-invasive neuromodulation that uses mechanical energy to affect neuronal excitability. LIFU confers high spatial resolution and adjustable focal lengths for precise neuromodulation of discrete regions in the human brain. Before the full potential of low intensity ultrasound for research and clinical application can be investigated, data on the safety of this technique is indicated. Here, we provide an evaluation of the safety of LIFU for human neuromodulation through participant report and neurological assessment with a comparison of symptomology to other forms of non-invasive brain stimulation. Participants (N = 120) that were enrolled in one of seven human ultrasound neuromodulation studies in one laboratory at the University of Minnesota (2015–2017) were queried to complete a follow-up Participant Report of Symptoms questionnaire assessing their self-reported experience and tolerance to participation in LIFU research (Isppa 11.56–17.12 W/cm2) and the perceived relation of symptoms to LIFU. A total of 64/120 participant (53%) responded to follow-up requests to complete the Participant Report of Symptoms questionnaire. None of the participants experienced serious adverse effects. From the post-hoc assessment of safety using the questionnaire, 7/64 reported mild to moderate symptoms, that were perceived as ‘possibly’ or ‘probably’ related to participation in LIFU experiments. These reports included neck pain, problems with attention, muscle twitches and anxiety. The most common unrelated symptoms included sleepiness and neck pain. There were initial transient reports of mild neck pain, scalp tingling and headache that were extinguished upon follow-up. No new symptoms were reported upon follow up out to 1 month. The profile and incidence of symptoms looks to be similar to other forms of non-invasive brain stimulation.
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Journal Article |
5 |
64 |
4
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Meekins GD, So Y, Quan D. American Association of Neuromuscular & Electrodiagnostic Medicine evidenced-based review: use of surface electromyography in the diagnosis and study of neuromuscular disorders. Muscle Nerve 2008; 38:1219-24. [PMID: 18816611 DOI: 10.1002/mus.21055] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Surface electromyography (sEMG) measures myoelectrical signals recorded from sensors placed on the skin surface. The non-invasive nature of sEMG makes it a potentially useful technology for studying diseases of muscle and nerve. Reviews published by the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) and the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology (AAN), covering 1964-1994 and 1952-1998, respectively, concluded that sEMG adds no clinical utility over conventional needle EMG (nEMG) for the diagnosis of neuromuscular disease. The AANEM sEMG task force reevaluated the diagnostic utility and added value of this technology for the study of neuromuscular disease based on a contemporary review of relevant literature published between January 1994 and February 2006. The present review concludes that sEMG may be useful to detect the presence of neuromuscular disease (level C rating, class III data), but there are insufficient data to support its utility for distinguishing between neuropathic and myopathic conditions or for the diagnosis of specific neuromuscular diseases. sEMG may be useful for additional study of fatigue associated with post-poliomyelitis syndrome and electromechanical function in myotonic dystrophy (level C rating, class III data).
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Review |
17 |
49 |
5
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Gillick B, Rich T, Nemanich S, Chen CY, Menk J, Mueller B, Chen M, Ward M, Meekins G, Feyma T, Krach L, Rudser K. Transcranial direct current stimulation and constraint-induced therapy in cerebral palsy: A randomized, blinded, sham-controlled clinical trial. Eur J Paediatr Neurol 2018; 22:358-368. [PMID: 29456128 PMCID: PMC5899638 DOI: 10.1016/j.ejpn.2018.02.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/22/2018] [Accepted: 02/01/2018] [Indexed: 12/16/2022]
Abstract
We investigated the safety, feasibility, and efficacy of transcranial direct current stimulation (tDCS) combined with constraint-induced movement therapy (CIMT) in children and young adults with unilateral cerebral palsy. Twenty participants were randomized to receive active or sham tDCS. The intervention consisted of 10 consecutive weekday sessions of tDCS applied to the non-lesioned hemisphere (20 min) concurrently with CIMT (120 min). Participants, caregivers, and interventionists were blinded to group assignment. The primary safety outcome investigated adverse events. The primary behavioral outcome was the Assisting Hand Assessment. All 20 participants (mean age = 12.7 yrs, range = 7.4-21.6 years) were evaluated for the primary outcomes. No serious adverse events occurred, and the most commonly reported minor adverse events were headache and itchiness. Both groups demonstrated a significant improvement in hand function after the intervention, although no significant effect of tDCS was observed (between-group difference = -2.18, 95% CI = [-6.48, 2.12], p = 0.30). Although hand function improved overall, no significant differences between intervention groups were found. Children with preserved corticospinal tract circuitry from the lesioned hemisphere, compared to those without, showed greater improvement in hand function (mean difference = 3.04, 95% CI = [-0.64, 6.72], p = 0.099). Our study demonstrates the safety and feasibility of serial sessions of tDCS, and presents preliminary evidence for the effect of CST circuitry on outcomes following tDCS/CIMT. Future work in children with unilateral cerebral palsy should focus on the optimal dosing and consider individual brain circuitry when describing response to combined interventions. CLINICAL TRIALS REGISTRATION Clinicaltrials.govNCT 02250092.
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Randomized Controlled Trial |
7 |
49 |
6
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Street VA, Meekins G, Lipe HP, Seltzer WK, Carter GT, Kraft GH, Bird TD. Charcot-Marie-Tooth neuropathy: clinical phenotypes of four novel mutations in the MPZ and Cx 32 genes. Neuromuscul Disord 2002; 12:643-50. [PMID: 12207932 DOI: 10.1016/s0960-8966(02)00021-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Charcot-Marie-Tooth Hereditary Neuropathy is a heterogeneous syndrome associated with mutations in several different genes including peripheral myelin protein 22, myelin P0, connexin 32, and early growth response 2. There is considerable variability in the phenotypic expression of this syndrome and the relationship of this variability to mutation genotypes requires extensive analysis. Here we describe the phenotypes and genotypes of four new mutations underlying the Charcot-Marie-Tooth syndrome and document segregation with disease. Four families with Charcot-Marie-Tooth were ascertained, examined, and evaluated electrophysiologically. Each family had peripheral blood DNA screened for mutations in myelin protein 22, myelin P0, and connexin 32. Two families were found with new mutations in the myelin P0 gene: S140T in the extracellular domain and K236del in the cytoplasmic domain. All families showed segregation of the mutations with the Charcot-Marie-Tooth phenotype as did a new family with the rare G163R mutation in the membrane domain. A 49-year-old man with the S140T mutation demonstrated conduction block on electrophysiological testing. A family with a novel S49P mutation in the connexin 32 gene had a neuropathy with very slow nerve conduction. These new mutations in the myelin P0 and connexin 32 genes help to clarify the pathophysiology of the clinical Charcot-Marie-Tooth syndrome. The S140T mutation in myelin P0 can be associated with conduction block and Charcot-Marie-Tooth should be part of the differential diagnosis of that phenomenon. Mutations in the cytoplasmic domain of myelin P0 can cause clinical neuropathy. The S49P mutation in the connexin 32 gene can produce aspects of a demyelinating type of X-linked hereditary neuropathy.
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23 |
27 |
7
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Rich TL, Menk JS, Rudser KD, Chen M, Meekins GD, Peña E, Feyma T, Bawroski K, Bush C, Gillick BT. Determining Electrode Placement for Transcranial Direct Current Stimulation: A Comparison of EEG- Versus TMS-Guided Methods. Clin EEG Neurosci 2017; 48:367-375. [PMID: 28530154 PMCID: PMC5933436 DOI: 10.1177/1550059417709177] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transcranial direct current stimulation (tDCS) is increasingly researched as an adjuvant to motor rehabilitation for children with hemiparesis. The optimal method for the primary motor cortex (M1) somatotopic localization for tDCS electrode placement has not been established. The objective, therefore, was to determine the location of the M1 derived using the 10/20 electroencephalography (EEG) system and transcranial magnetic stimulation (TMS) in children with hemiparesis (CWH) and a comparison group of typically developing children (TDC). We hypothesized a difference in location for CWH but not for TDC. The 2 locations were evaluated in 47 children (21 CWH, 26 TDC). Distances between the locations were measured pending presence of a motor evoked potential. Distances between the EEG and TMS locations that exceeded the 2.5 cm × 2.5 cm rubber electrode area are reported in percentages [95% confidence interval] in CWH-nonlesioned hemisphere was 68.8% [41.3-89.0], lesioned: 85.7% [57.2-98.2]; TDC-dominant hemisphere 73.9% [51.6-89.8], nondominant: 82.6% [61.2-95.0]. Distances that exceeded the 3 × 5 cm electrode sponge area in CWH-nonlesioned was 25.0% [7.3-52.4], lesioned was 28.6% [8.4-58.1]; TDC-dominant was 52.2% [30.6-73.2], nondominant was 43.5 [23.2-65.5]). Distances that exceeded the 5 × 7 cm electrode sponge area in CWH-nonlesioned was 18.8% [4.0-45.6] and lesioned was 21.4% [4.7-50.8]; TDC-dominant was 21.7% [7.5-43.7] and nondominant was 26.1% [10.2-48.4]. Individual variability in brain somatotopic organization may influence surface scalp localization of underlying M1 in children regardless of neurologic impairment. Findings suggest further investigation of optimal tDCS electrode placement. EEG and TMS methods reveal variability in localizing M1 in children regardless of stroke diagnosis. This study was registered on clinicaltrials.gov NCT02015338.
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Comparative Study |
8 |
25 |
8
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Gillick B, Menk J, Mueller B, Meekins G, Krach LE, Feyma T, Rudser K. Synergistic effect of combined transcranial direct current stimulation/constraint-induced movement therapy in children and young adults with hemiparesis: study protocol. BMC Pediatr 2015; 15:178. [PMID: 26558386 PMCID: PMC4642615 DOI: 10.1186/s12887-015-0498-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 10/27/2015] [Indexed: 11/10/2022] Open
Abstract
Background Perinatal stroke occurs in more than 1 in 2,500 live births and resultant congenital hemiparesis necessitates investigation into interventions which may improve long-term function and decreased burden of care beyond current therapies (http://www.cdc.gov/ncbddd/cp/data.html). Constraint-Induced Movement Therapy (CIMT) is recognized as an effective hemiparesis rehabilitation intervention . Transcranial direct current stimulation as an adjunct treatment to CIMT may potentiate neuroplastic responses and improve motor function. The methodology of a clinical trial in children designed as a placebo-controlled, serial –session, non-invasive brain stimulation trial incorporating CIMT is described here. The primary hypotheses are 1) that no serious adverse events will occur in children receiving non-invasive brain stimulation and 2) that children in the stimulation intervention group will show significant improvements in hand motor function compared to children in the placebo stimulation control group. Methods/design A randomized, controlled, double-blinded clinical trial. Twenty children and/or young adults (ages 8–21) with congenital hemiparesis, will be enrolled. The intervention group will receive ten 2-hour sessions of transcranial direct current stimulation combined with constraint-induced movement therapy and the control group will receive sham stimulation with CIMT. The primary outcome measure is safety assessment of transcranial direct current stimulation by physician evaluation, vital sign monitoring and symptom reports. Additionally, hand function will be evaluated using the Assisting Hand Assessment, grip strength and assessment of goals using the Canadian Occupational Performance Measure. Neuroimaging will confirm diagnoses, corticospinal tract integrity and cortical activation. Motor cortical excitability will also be examined using transcranial magnetic stimulation techniques. Discussion Combining non-invasive brain stimulation and CIMT interventions has the potential to improve motor function in children with congenital hemiparesis beyond each intervention independently. Such a combined intervention has the potential to benefit an individual throughout their lifetime. Trial registration Clinicaltrials.gov, NCT02250092Registered 18 September 2014
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Research Support, Non-U.S. Gov't |
10 |
24 |
9
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Abstract
Sciatic nerve compression very rarely occurs bilaterally. The authors present a woman with profound lower extremity weakness and sensory abnormality after falling asleep in the head-to-knees yoga position (also called "Paschimottanasana"). Clinical and electrodiagnostic findings are discussed in detail and a brief review of the literature is presented.
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Journal Article |
20 |
22 |
10
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Meekins GD, Emery MJ, Weiss MD. Nerve conduction abnormalities in the trembler-j mouse: a model for Charcot-Marie-Tooth disease type 1A? J Peripher Nerv Syst 2004; 9:177-82. [PMID: 15363066 DOI: 10.1111/j.1085-9489.2004.09310.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The trembler-j mouse is a spontaneously occurring, demyelinating mutant secondary to a point mutation involving a leucine for proline substitution in the first transmembrane domain of the peripheral-myelin protein-22 (PMP-22) gene. It is considered to be a model for Charcot-Marie-Tooth disease type 1A (CMT1A), largely based upon pathologic observations. However, functional studies demonstrating homology with CMT1A patients have not been documented. Sciatic nerve conduction was performed on 30 and 72-day-old wildtype and trembler-j mice in a blinded fashion. The findings in the mutants in both age groups were consistent with profound demyelination. Trembler-j mice appear to have a greater degree of motor nerve conduction slowing relative to human studies involving patients with PMP-22 gene duplication. Functionally, the trembler-j is a good murine model for CMT1A associated with an identical point mutation but may represent a more severe disease phenotype than CMT1A secondary to PMP-22 gene duplication.
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Journal Article |
21 |
16 |
11
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Gröhn H, Gillick BT, Tkáč I, Bednařík P, Mascali D, Deelchand DK, Michaeli S, Meekins GD, Leffler-McCabe MJ, MacKinnon CD, Eberly LE, Mangia S. Influence of Repetitive Transcranial Magnetic Stimulation on Human Neurochemistry and Functional Connectivity: A Pilot MRI/MRS Study at 7 T. Front Neurosci 2019; 13:1260. [PMID: 31827419 PMCID: PMC6890551 DOI: 10.3389/fnins.2019.01260] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 11/06/2019] [Indexed: 12/13/2022] Open
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation method commonly used in the disciplines of neuroscience, neurology, and neuropsychiatry to examine or modulate brain function. Low frequency rTMS (e.g., 1 Hz) is associated with a net suppression of cortical excitability, whereas higher frequencies (e.g., 5 Hz) purportedly increase excitability. Magnetic resonance spectroscopy (MRS) and resting-state functional MRI (rsfMRI) allow investigation of neurochemistry and functional connectivity, respectively, and can assess the influence of rTMS in these domains. This pilot study investigated the effects of rTMS on the primary motor cortex using pre and post MRS and rsfMRI assessments at 7 T. Seven right-handed males (age 27 ± 7 y.o.) underwent single-voxel MRS and rsfMRI before and about 30-min after rTMS was administered outside the scanner for 20-min over the primary motor cortex of the left (dominant) hemisphere. All participants received 1-Hz rTMS; one participant additionally received 5-Hz rTMS in a separate session. Concentrations of 17 neurochemicals were quantified in left and right motor cortices. Connectivity metrics included fractional amplitude of low-frequency fluctuations (fALFF) and regional homogeneity (ReHo) of both motor cortices, strength of related brain networks, and inter-hemispheric connectivity. The group-analysis revealed few trends (i.e., uncorrected for multiple comparisons), including a mean increase in the concentration of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) after the inhibitory rTMS protocol as compared to baseline in the stimulated (left) motor cortex (+8%, p = 0.043), along with a slight increase of total creatine (+2%, p = 0.018), and decrease of aspartate (-18%, p = 0.016). Additionally, GABA tended to decrease in the contralateral hemisphere (-6%, p = 0.033). No other changes of metabolite concentrations were found. Whereas functional connectivity outcomes did not exhibit trends of significant changes induced by rTMS, the percent changes of few connectivity metrics in both hemispheres were negatively correlated with GABA changes in the contralateral hemisphere. While studies in larger cohorts are needed to confirm these preliminary findings, our results indicate the safety and feasibility of detecting changes in key metabolites associated with neurotransmission after a single 1-Hz rTMS session, establishing the construct for future exploration of the neurochemical, and connectivity mechanisms of cortical responses to neuromodulation.
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Journal Article |
6 |
16 |
12
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Weiss MD, Oakley JC, Meekins GD. Hypoglossal neuropathy in Lewis-Sumner syndrome masquerading as motor neuron disease. Neurology 2006; 67:175-6. [PMID: 16832106 DOI: 10.1212/01.wnl.0000223577.69111.2c] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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19 |
14 |
13
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Meekins GD, Carter GT, Emery MJ, Weiss MD. Axonal degeneration in the Trembler-j mouse demonstrated by stimulated single-fiber electromyography. Muscle Nerve 2007; 36:81-6. [PMID: 17443662 DOI: 10.1002/mus.20786] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The Trembler-j (Tr-j) mouse is a naturally occurring mutant with a point mutation in the peripheral myelin protein-22 gene causing severe peripheral nerve demyelination. It is a genetically homologous murine model for Charcot-Marie-Tooth disease type 1A (CMT 1A). Our prior pilot studies using stimulated single-fiber needle electromyograpy (SSFEMG) showed increased jitter in 60-day-old Tr-j mice compared to age-matched, wildtype animals. The aim of this study was to better elucidate the etiology of increased jitter in Tr-j mice and test the following hypotheses: (1) the increased jitter in Tr-j mice is due to turnover of endplates secondary to axonal degeneration with reinnervation and not to conduction block secondary to demyelination of motor nerve axons; and (2) aging Tr-j mice demonstrate increased jitter and fiber density compared with younger mutant mice due to progressive motor axon loss. SSFEMG studies performed on 60- and 140-day-old mice indicated that average mean consecutive difference (MCD) and fiber density estimates (FDE) were significantly increased in Tr-j mice at both ages compared to age-matched wildtypes. FDE also increased substantially in older mutant mice. Intraperitoneal neostigmine injections produced significant reductions in average MCD in Tr-j mice, suggesting that impaired neuromuscular transmission is an early pathologic feature in these mice and likely reflects distal axonal degeneration. Our findings corroborate our prior pilot study, although in a much larger number of animals across a wider age span. Our study also indicates that SSFEMG, performed in a serial fashion, is a useful, noninvasive method of detecting progressive axon loss in this murine model of CMT 1A. This technique may be a valuable tool to study the affects of genetic or pharmaceutical interventions in murine models of peripheral neuropathy. Muscle Nerve, 2007.
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Research Support, Non-U.S. Gov't |
18 |
12 |
14
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Nemanich ST, Rich TL, Chen CY, Menk J, Rudser K, Chen M, Meekins G, Gillick BT. Influence of Combined Transcranial Direct Current Stimulation and Motor Training on Corticospinal Excitability in Children With Unilateral Cerebral Palsy. Front Hum Neurosci 2019; 13:137. [PMID: 31105541 PMCID: PMC6492624 DOI: 10.3389/fnhum.2019.00137] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/08/2019] [Indexed: 11/13/2022] Open
Abstract
Combined non-invasive brain stimulation (NIBS) and rehabilitation interventions have the potential to improve function in children with unilateral cerebral palsy (UCP), however their effects on developing brain function are not well understood. In a proof-of-principle study, we used single-pulse transcranial magnetic stimulation (TMS) to measure changes in corticospinal excitability and relationships to motor performance following a randomized controlled trial consisting of 10 days of combined constraint-induced movement therapy (CIMT) and cathodal transcranial direct current stimulation (tDCS) applied to the contralesional motor cortex. Twenty children and young adults (mean age = 12 years, 9 months, range = 7 years, 7 months, 21 years, 7 months) with UCP participated. TMS testing was performed before, after, and 6 months after the intervention to measure motor evoked potential (MEP) amplitude and cortical silent period (CSP) duration. The association between neurophysiologic and motor outcomes and differences in excitability between hemispheres were examined. Contralesional MEP amplitude decreased as hypothesized in five of five participants receiving active tDCS immediately after and 6 months after the intervention, however no statistically significant differences between intervention groups were noted for MEP amplitude [mean difference = −323.9 μV, 95% CI = (−989, 341), p = 0.34] or CSP duration [mean difference = 3.9 ms, 95% CI = (−7.7, 15.5), p = 0.51]. Changes in corticospinal excitability were not statistically associated with improvements in hand function after the intervention. Across all participants, MEP amplitudes measured in the more-affected hand from both contralesional (mean difference = −474.5 μV) and ipsilesional hemispheres (−624.5 μV) were smaller compared to the less-affected hand. Assessing neurophysiologic changes after tDCS in children with UCP provides an understanding of long-term effects on brain excitability to help determine its potential as a therapeutic intervention. Additional investigation into the neurophysiologic effects of tDCS in larger samples of children with UCP are needed to confirm these findings.
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Journal Article |
6 |
10 |
15
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Gillick BT, Rich T, Chen M, Meekins GD. Case report of vasovagal syncope associated with single pulse transcranial magnetic stimulation in a healthy adult participant. BMC Neurol 2015; 15:248. [PMID: 26627895 PMCID: PMC4666029 DOI: 10.1186/s12883-015-0510-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 11/27/2015] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Non-invasive brain stimulation-related seizures or syncopal events are rare. However, we report on a syncopal event in a healthy female during a transcranial magnetic stimulation single-pulse testing session. CASE PRESENTATION A 47-year-old healthy female presented for a transcranial magnetic stimulation session involving single-pulse assessment of cortical excitability. During the session, the participant appeared to have a brief event involving fainting and myoclonic jerks of the upper extremities. Orthostatic assessment was performed after the event and physician evaluation determined that this was a vasovagal syncopal event. The ethical aspects of this neurophysiology testing protocol were reviewed by the University of Minnesota Institutional Review Board (IRB), and formal IRB approval was deemed unnecessary for single-pulse assessment of healthy control participants not directly involved in a research study. Informed consent was obtained by the participant, including review of potential adverse events. CONCLUSION Although rare and rarely reported, vasovagal syncopal events surrounding non-invasive brain stimulation do occur. Thorough pre-screening should incorporate assessment of history of syncope and a plan for risk mitigation if such an event should occur. A complete assessment of the impact of stimulation on the autonomic nervous system is unknown. As such studies expand into patients with myriad neurologic diagnoses, further studies on this effect, in both healthy control and patient populations, are warranted. Such knowledge could contribute to identification of the optimal study participant, and improvements in techniques of stimulation administration.
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Research Support, Non-U.S. Gov't |
10 |
9 |
16
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Distad BJ, Meekins GD, Liou LL, Weiss MD, Carter GT, Miller RG. Drug therapy in amyotrophic lateral sclerosis. Phys Med Rehabil Clin N Am 2008; 19:633-51, xi-xii. [PMID: 18625421 DOI: 10.1016/j.pmr.2008.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating condition characterized by progressive muscle wasting, inanition, respiratory failure, and death within approximately 2 to 5 years of onset. ALS is among the most common neuromuscular conditions, with an overall prevalence in the world of approximately 5 to 7 cases/100,000 population. Epidemiologic studies have identified some potential risk factors for developing ALS, including a high-fat, low-fiber diet; cigarette smoking; slimness and athleticism; and living in urban areas. Between 5% and 10% of ALS is genetic, with up to 11 genetic loci identified. Although understanding of the pathophysiology of this disease has advanced over the past 60 years, scant progress has been made regarding effective treatment. The authors review the current understanding of the pathogenic mechanisms of ALS and approaches to treating the disease.
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Review |
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Meekins GD, Weiss MD. Electrodiagnostic Studies in a Murine Model of Demyelinating Charcot-Marie-Tooth Disease. Phys Med Rehabil Clin N Am 2005; 16:967-79, ix. [PMID: 16214054 DOI: 10.1016/j.pmr.2005.08.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Smith R, Pioro E, Myers K, Sirdofsky M, Goslin K, Meekins G, Yu H, Wymer J, Cudkowicz M, Macklin EA, Schoenfeld D, Pattee G. Erratum to: Enhanced Bulbar Function in Amyotrophic Lateral Sclerosis: The Nuedexta Treatment Trial. Neurotherapeutics 2017; 14:830. [PMID: 28283968 PMCID: PMC5509622 DOI: 10.1007/s13311-017-0517-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Published Erratum |
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Nemanich ST, Lench DH, Sutter EN, Kowalski JL, Francis SM, Meekins GD, Krach LE, Feyma T, Gillick BT. Safety and feasibility of transcranial direct current stimulation stratified by corticospinal organization in children with hemiparesis. Eur J Paediatr Neurol 2023; 43:27-35. [PMID: 36878110 PMCID: PMC10117060 DOI: 10.1016/j.ejpn.2023.01.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/13/2023] [Accepted: 01/25/2023] [Indexed: 03/04/2023]
Abstract
Children with hemiparesis (CWH) due to stroke early in life face lifelong impairments in motor function. Transcranial direct current stimulation (tDCS) may be a safe and feasible adjuvant therapy to augment rehabilitation. Given the variability in outcomes following tDCS, tailored protocols of tDCS are required. We evaluated the safety, feasibility, and preliminary effects of a single session of targeted anodal tDCS based on individual corticospinal tract organization on corticospinal excitability. Fourteen CWH (age = 13.8 ± 3.63) were stratified into two corticospinal organization subgroups based on transcranial magnetic stimulation (TMS)-confirmed motor evoked potentials (MEP): ipsilesional MEP presence (MEPIL+) or absence (MEPIL-). Subgroups were randomized to real anodal or sham tDCS (1.5 mA, 20 min) applied to the ipsilesional (MEPIL + group) or contralesional (MEPIL- group) hemisphere combined with hand training. Safety was assessed with questionnaires and motor function evaluation, and corticospinal excitability was assessed at baseline and every 15 min for 1 h after tDCS. No serious adverse events occurred and anticipated minor side effects were reported and were self-limiting. Six of 14 participants had consistent ipsilesional MEPs (MEPIL + group). Paretic hand MEP amplitude increased in 5/8 participants who received real anodal tDCS to either the ipsilesional or contralesional hemisphere (+80% change). Application of tDCS based on individual corticospinal organization was safe and feasible with expected effects on excitability, indicating the potential for tailored tDCS protocols for CWH. Additional research involving expanded experimental designs is needed to confirm these effects and to determine if this approach can be translated into a clinically relevant intervention.
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Randomized Controlled Trial |
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Delatorre RG, Sutter EN, Nemanich ST, Krach LE, Meekins G, Feyma T, Gillick BT. Anodal Contralesional tDCS Enhances CST Excitability Bilaterally in an Adolescent with Hemiparetic Cerebral Palsy: A Brief Report. Dev Neurorehabil 2023; 26:216-221. [PMID: 36967533 PMCID: PMC10228174 DOI: 10.1080/17518423.2023.2193626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 01/08/2023] [Accepted: 03/17/2023] [Indexed: 04/11/2023]
Abstract
Hemiparetic cerebral palsy (HCP), weakness on one side of the body typically caused by perinatal stroke, is characterized by lifelong motor impairments related to alterations in the corticospinal tract (CST). CST reorganization could be a useful biomarker to guide applications of neuromodulatory interventions, such as transcranial direct current stimulation (tDCS), to improve the effectiveness of rehabilitation therapies. We evaluated an adolescent with HCP and CST reorganization who demonstrated persistent heightened CST excitability in both upper limbs following anodal contralesional tDCS. The results support further investigation of targeted tDCS as an adjuvant therapy to traditional neurorehabilitation for upper limb function.
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research-article |
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Rich T, Chen CY, Feyma T, Meekins G, Ward M, Krach LE, Gillick B. Child and Caregiver Perspectives of a Combined Brain Stimulation and Constraint-Induced Movement Therapy Trial. Am J Occup Ther 2017. [DOI: 10.5014/ajot.2017.71s1-po4141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Abstract
Date Presented 3/31/2017
Novel interventions pairing noninvasive brain stimulation and rehabilitation are emerging for children with stroke. Feedback from pediatric clinical trial participants and caregivers is reviewed to guide future investigations and translation of novel interventions.
Primary Author and Speaker: Tonya Rich
Contributing Authors: Chao-Ying Chen, Timothy Feyma, Gregg Meekins, Marcie Ward, Linda E. Krach, Bernadette Gillick
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