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Christiansen L, Chen B, Lei Y, Urbin MA, Richardson MSA, Oudega M, Sandhu M, Rymer WZ, Trumbower RD, Mitchell GS, Perez MA. Acute intermittent hypoxia boosts spinal plasticity in humans with tetraplegia. Exp Neurol 2020; 335:113483. [PMID: 32987000 DOI: 10.1016/j.expneurol.2020.113483] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/31/2020] [Accepted: 09/22/2020] [Indexed: 12/19/2022]
Abstract
Paired corticospinal-motoneuronal stimulation (PCMS) elicits spinal synaptic plasticity in humans with chronic incomplete cervical spinal cord injury (SCI). Here, we examined whether PCMS-induced plasticity could be potentiated by acute intermittent hypoxia (AIH), a treatment also known to induce spinal synaptic plasticity in humans with chronic incomplete cervical SCI. During PCMS, we used 180 pairs of stimuli where corticospinal volleys evoked by transcranial magnetic stimulation over the hand representation of the primary motor cortex were timed to arrive at corticospinal-motoneuronal synapses of the first dorsal interosseous (FDI) muscle ~1-2 ms before the arrival of antidromic potentials elicited in motoneurons by electrical stimulation of the ulnar nerve. During AIH, participants were exposed to brief alternating episodes of hypoxic inspired gas (1 min episodes of 9% O2) and room air (1 min episodes of 20.9% O2). We examined corticospinal function by measuring motor evoked potentials (MEPs) elicited by cortical and subcortical stimulation of corticospinal axons and voluntary motor output in the FDI muscle before and after 30 min of PCMS combined with AIH (PCMS+AIH) or sham AIH (PCMS+sham-AIH). The amplitude of MEPs evoked by magnetic and electrical stimulation increased after both protocols, but most after PCMS+AIH, consistent with the hypothesis that their combined effects arise from spinal plasticity. Both protocols increased electromyographic activity in the FDI muscle to a similar extent. Thus, PCMS effects on spinal synapses of hand motoneurons can be potentiated by AIH. The possibility of different thresholds for physiological vs behavioral gains needs to be considered during combinatorial treatments.
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Affiliation(s)
- Lasse Christiansen
- University of Miami, Department of Neurological Surgery, The Miami Project to Cure Paralysis and Miami VA Medical Center, Miami, FL, 33136, United States of America; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital, Amager and Hvidovre, Denmark
| | - Bing Chen
- University of Miami, Department of Neurological Surgery, The Miami Project to Cure Paralysis and Miami VA Medical Center, Miami, FL, 33136, United States of America; Shirley Ryan AbilityLab, Northwestern University, Chicago, IL 60611, United States of America
| | - Yuming Lei
- University of Miami, Department of Neurological Surgery, The Miami Project to Cure Paralysis and Miami VA Medical Center, Miami, FL, 33136, United States of America
| | - M A Urbin
- University of Miami, Department of Neurological Surgery, The Miami Project to Cure Paralysis and Miami VA Medical Center, Miami, FL, 33136, United States of America
| | | | - Martin Oudega
- University of Miami, Department of Neurological Surgery, The Miami Project to Cure Paralysis and Miami VA Medical Center, Miami, FL, 33136, United States of America; Shirley Ryan AbilityLab, Northwestern University, Chicago, IL 60611, United States of America; Edward Jr. Hines VA Hospital, Chicago, IL 60141, United States of America; Department of Physical Therapy and Human Movement Sciences, Northwestern University, Northwestern University, Chicago, IL 60611, United States of America; Affiliated Cancer Hospital & Institute, Guangzhou Medical University, Guangzhou, Guangdong 510095, PR China
| | - Milap Sandhu
- Shirley Ryan AbilityLab, Northwestern University, Chicago, IL 60611, United States of America
| | - W Zev Rymer
- Shirley Ryan AbilityLab, Northwestern University, Chicago, IL 60611, United States of America
| | - Randy D Trumbower
- Spaulding Rehabilitation Hospital, Cambridge Street, Cambridge, MA 02138, United States of America; Harvard Medical School, Department of Physical Medicine & Rehabilitation, Boston, MA 02115, United States of America
| | - Gordon S Mitchell
- Center for Respiratory Research and Rehabilitation, Department of Physical Therapy and McKnight Brain Institute, University of Florida, Gainesville, FL 32610, United States of America
| | - Monica A Perez
- University of Miami, Department of Neurological Surgery, The Miami Project to Cure Paralysis and Miami VA Medical Center, Miami, FL, 33136, United States of America; Shirley Ryan AbilityLab, Northwestern University, Chicago, IL 60611, United States of America; Edward Jr. Hines VA Hospital, Chicago, IL 60141, United States of America; Department of Physical Therapy and Human Movement Sciences, Northwestern University, Northwestern University, Chicago, IL 60611, United States of America.
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Kamble N, Netravathi M, Nagaraju BC, Lenka A, Kumar K, Sowmya V, Jain S, Pal PK. Evaluation of Cognition and Cortical Excitability in Huntington's Disease. Can J Neurol Sci 2018; 45:176-81. [PMID: 29307324 DOI: 10.1017/cjn.2017.277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Recent advances in neurophysiological techniques have contributed to our understanding of the pathophysiology of Huntington's disease (HD). Studies of the motor cortical excitability and central motor pathways have shown variable results. OBJECTIVES Our aims were to evaluate the cortical excitability changes in HD using transcranial magnetic stimulation (TMS) and correlate the changes with cognitive impairment. METHODS The study included 32 HD patients and 30 age- and gender-matched controls. The demographic and clinical profiles of the patients were recorded. All subjects were evaluated by TMS and resting motor threshold (RMT), central motor conduction time (CMCT), silent period (SP), short-interval intracortical inhibition (SICI), and intracortical facilitation were determined. A battery of neuropsychological tests was administered to all subjects. RESULTS The mean age of the patients was 42.1±14.1 years, and that of controls 39.4±12.4 years (p=0.61). There was no significant difference in RMT and CMCT between the two groups. There was a mild prolongation of the contralateral SP in HD, but it was not significant. SICI was significantly reduced in HD (p<0.0001). A significant impairment in attention, verbal fluency, executive function, visuospatial function, learning, and memory was observed in HD patients. However, there was no correlation between cortical excitability changes and cognitive impairment. CONCLUSIONS TMS is a valuable method of evaluating cortical excitability changes in HD. These patients have reduced SICI and significant impairment of cognition in multiple domains.
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