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Hippocampal Mitochondrial Abnormalities Induced the Dendritic Complexity Reduction and Cognitive Decline in a Rat Model of Spinal Cord Injury. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:9253916. [PMID: 35571236 PMCID: PMC9095360 DOI: 10.1155/2022/9253916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 03/19/2022] [Accepted: 04/12/2022] [Indexed: 11/18/2022]
Abstract
Spinal cord injury (SCI) is a progressive neurodegenerative disease in addition to a traumatic event. Cognitive dysfunction following SCI has been widely reported in patients and animal models. However, the neuroanatomical changes affecting cognitive function after SCI, as well as the mechanisms behind these changes, have so far remained elusive. Herein, we found that SCI accelerates oxidative stress damage of hippocampal neuronal mitochondria. Then, for the first time, we presented a three-dimensional morphological atlas of rat hippocampal neurons generated using a fluorescence Micro-Optical Sectioning Tomography system, a method that accurately identifies the spatial localization of neurons and trace neurites. We showed that the number of dendritic branches and dendritic length was decreased in late stage of SCI. Western blot and transmission electron microscopy analyses also showed a decrease in synaptic communication. In addition, a battery of behavioral tests in these animals revealed hippocampal based cognitive dysfunction, which could be attributed to changes in the dendritic complexity of hippocampal neurons. Taken together, these results suggested that mitochondrial abnormalities in hippocampal neurons induced the dendritic complexity reduction and cognitive decline following SCI. Our study highlights the neuroanatomical basis and importance of mitochondria in brain degeneration following SCI, which might contribute to propose new therapeutic strategies.
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Heled E, Tal K, Zeilig G. Does lack of brain injury mean lack of cognitive impairment in traumatic spinal cord injury? J Spinal Cord Med 2022; 45:373-380. [PMID: 33320804 PMCID: PMC9135427 DOI: 10.1080/10790268.2020.1847564] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE Traumatic spinal cord injury (tSCI) has implications in many areas, including cognitive functioning. Findings regarding cognitive problems in people with SCI are inconsistent, presumably due to multiple variables than can affect performance, among them emotional variables. The purpose of the current study was to elucidate cognitive sequalae in some individuals with tSCI with no medical record of brain injury, while taking emotional variables into consideration. DESIGN Cross-sectional, with two groups. SETTING A public rehabilitation center. PARTICIPANTS Twenty participants with tSCI at least ten months post injury and twenty non-SCI controls, matched for sex, age, and education. INTERVENTION None. OUTCOME MEASURES A battery of neuropsychological tests tapping executive functions, memory, attention, and naming abilities, in addition to questionnaires assessing depression and distress. RESULTS When emotional variables were statistically controlled, participants with tSCI showed higher levels of depression and distress and scored lower than non-SCI control participants on all cognitive tests except naming. Executive functions were found to have the highest effect size, though no specific ability was sensitive enough to differentiate between the groups in a binary logistic regression analysis. CONCLUSION In some individuals with chronic tSCI, lower cognitive ability that is unrelated to emotional distress might result from spinal cord damage and its implications in a population who's medical records show no indication of brain injury. This highlights the importance of conducting cognitive evaluation following SCI, so that deficits can be effectively addressed during rehabilitation.
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Affiliation(s)
- Eyal Heled
- Department of Psychology, Ariel University, Ariel, Israel,Department of Neurological Rehabilitation, Sheba Medical Center, Ramat-Gan, Israel,Correspondence to: Eyal Heled, Department of Psychology, Ariel University, Ariel, Israel; Ph: +972-502-310313; +972-3-9191437.
| | - Keren Tal
- Department of Psychology, Ariel University, Ariel, Israel
| | - Gabi Zeilig
- Department of Neurological Rehabilitation, Sheba Medical Center, Ramat-Gan, Israel,Department of Physical Medicine and Rehabilitation, Sackler School of Medicine, Tel Aviv University, Tel-Aviv, Israel
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Dudley-Javoroski S, Lee J, Shields RK. Cognitive function, quality of life, and aging: relationships in individuals with and without spinal cord injury. Physiother Theory Pract 2022; 38:36-45. [PMID: 31914347 PMCID: PMC7702216 DOI: 10.1080/09593985.2020.1712755] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Background: Correlations between aging, cognitive impairment and poor quality of life (QOL) have been observed for many patient populations.Objective: The purpose of this study was to examine these correlations in individuals with and without spinal cord injury (SCI).Methods: 23 individuals with complete SCI and 20 individuals without SCI ("NON") underwent assessment of cognitive function via the NIH Toolbox for Neurological and Behavioral Function. Participants self-rated QOL via global and symptom/domain-specific measures.Results: SCI rated global QOL to be lower than NON for the EQ-5D QALY (p < .001), but not the EQ-5D VAS, which imposes no penalty for wheeled mobility. Low QOL clustered mainly in domains pertaining to physical function/symptoms. Participants with SCI reported high QOL for positive affect/well-being and resilience. Cognitive function in SCI did not differ from NON. However, strong correlations between age and cognition observed in NON (all R2 > 0.532) were absent in SCI. Significant correlations between cognition and QOL were prevalent for NON but not for SCI.Conclusions: Dissociation of age, cognition and QOL occurred with SCI. Divergence between EQ-5D QALY and VAS suggests that individuals with SCI may recalibrate personal assessments of QOL in ways that minimize the importance of mobility impairment.
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Lee J, Dudley-Javoroski S, Shields RK. Motor demands of cognitive testing may artificially reduce executive function scores in individuals with spinal cord injury. J Spinal Cord Med 2021; 44:253-261. [PMID: 30943119 PMCID: PMC7952072 DOI: 10.1080/10790268.2019.1597482] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Objective: To determine whether the motor demands of cognitive tests contribute to differences in cognitive function scores in participants with and without spinal cord injury (SCI).Design: Cohort study.Setting: Rehabilitation research laboratory.Participants: 68 individuals without SCI ("NON") and 22 individuals with motor complete SCI ("SCI").Interventions: None.Outcome Measures: NIH Toolbox cognitive assessments, including two with motor demands and reaction-time based scoring (Dimensional Change Card Sort (DCCS), Flanker Inhibitory Control and Attention (Flanker) and two without timed scoring (List Sorting Working Memory (List Sorting), Picture Sequence Memory Test (Picture Sequence). Tests were administered with and without the assistance of a proctor on two randomly-determined days (>24 hr interval). For DCCS and Flanker, the motor-task score offset was estimated as the difference between the proctored and non-proctored scores.Results: For demographically-corrected data, proctoring reduced DCCS and Flanker scores (P < 0.001) but mitigated apparent differences between SCI and NON (all P > 0.403). SCI and NON did not differ for List Sorting (P > 0.072) but did differ significantly for Picture Sequence (P < 0.001). Significant practice effects existed for memory-based tests (List Sorting and Picture Sequence); all P < 0.015, effect size>0.645.Conclusions: DCCS and Flanker scores for individuals with SCI may be artificially reduced consequent to secondary motor demands of the tests. Proctoring and computation of a motor-response score offset enables comparisons to be made between individuals with SCI and a Non-SCI control cohort; however, further work is needed to determine whether offset-adjusted scores can be compared to standardized normative values.
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Affiliation(s)
- Jinhyun Lee
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Shauna Dudley-Javoroski
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Richard K. Shields
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA,Correspondence to: Richard K. Shields, Department of Physical Therapy and Rehabilitation Science, University of Iowa, 1-252 Medical Education Building, Iowa City, IA52242, USA.
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Wylie GR, Chiaravalloti ND, Weber E, Genova HM, Dyson-Hudson TA, Wecht JM. The Neural Mechanisms Underlying Processing Speed Deficits in Individuals Who Have Sustained a Spinal Cord Injury: A Pilot Study. Brain Topogr 2020; 33:776-784. [PMID: 32978697 DOI: 10.1007/s10548-020-00798-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 09/11/2020] [Indexed: 02/06/2023]
Abstract
Our objective was to determine differences in brain activation during a processing-speed task in individuals with SCI compared to a group of age-matched healthy controls and to a group of older healthy controls. Ten individuals with cervical SCI (C3-C5), 10 age-matched healthy controls and 10 older healthy controls participated in a cross-sectional study in which performance on neuropsychological tests of processing speed and brain activation were the main outcome measures. The brain areas used by the individuals with SCI during the processing-speed task differed significantly from the age-matched healthy controls, but were similar to the older control cohort, and included activation in frontal, parietal and hippocampal areas. This suggests that individuals with SCI may compensate for processing-speed deficits by relying on brain regions that classically support control cognitive processes such as executive control and memory.
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Affiliation(s)
- Glenn R Wylie
- Kessler Foundation, Rocco Ortenzio Neuroimaging Center, 1199 Pleasant Valley Way, West Orange, NJ, 07052, USA.
- Department of Physical Medicine and Rehabilitation, Rutgers-NJ Medical School, Newark, NJ, USA.
- Department of Veterans' Affairs, War Related Illness & Injury Study Center, East Orange, NJ, USA.
| | - Nancy D Chiaravalloti
- Kessler Foundation, Rocco Ortenzio Neuroimaging Center, 1199 Pleasant Valley Way, West Orange, NJ, 07052, USA
- Department of Physical Medicine and Rehabilitation, Rutgers-NJ Medical School, Newark, NJ, USA
| | - Erica Weber
- Kessler Foundation, Rocco Ortenzio Neuroimaging Center, 1199 Pleasant Valley Way, West Orange, NJ, 07052, USA
| | - Helen M Genova
- Kessler Foundation, Rocco Ortenzio Neuroimaging Center, 1199 Pleasant Valley Way, West Orange, NJ, 07052, USA
- Department of Physical Medicine and Rehabilitation, Rutgers-NJ Medical School, Newark, NJ, USA
| | - Trevor A Dyson-Hudson
- Kessler Foundation, Rocco Ortenzio Neuroimaging Center, 1199 Pleasant Valley Way, West Orange, NJ, 07052, USA
- Department of Physical Medicine and Rehabilitation, Rutgers-NJ Medical School, Newark, NJ, USA
| | - Jill M Wecht
- Department of Veterans' Affairs, RR&D National Center for the Medical Consequences of SCI, James J. Peters VAMC, Bronx, NY, USA
- Department of Medicine, The Icahn School of Medicine, Mount Sinai, New York, NY, USA
- Department of Rehabilitation Medicine, The Icahn School of Medicine, Mount Sinai, New York, NY, USA
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Tal A, Vakil E. How sequence learning unfolds: Insights from anticipatory eye movements. Cognition 2020; 201:104291. [PMID: 32497894 DOI: 10.1016/j.cognition.2020.104291] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 03/31/2020] [Accepted: 04/03/2020] [Indexed: 11/21/2022]
Abstract
The acquisition of sequential knowledge is pivotal in forming skilled behavior. Despite extensive research of sequence learning, much remains unknown regarding what knowledge participants learn in such studies, and how that knowledge takes form over time. By tracking eye-movements made before stimuli appear on screen during a serial reaction time (SRT) task, we devised a method for assessing learning at the individual participant level in an item-based resolution. Our method enables uncovering what participants actually learn about the sequence presented to them, and when. Results demonstrate that learning is more heterogeneous than previously thought, driven by learning both of chunks and of statistics embedded in the sequence. Also, learning develops rapidly, but in a fragmented and non-sequential manner, eventually encompassing only a subset of available regularities. The tools developed in this work may aid in further dissociating processes and mechanisms underlying sequence learning and its impairments, in normal and in clinical populations.
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Affiliation(s)
- Amir Tal
- Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan 52900, Israel.
| | - Eli Vakil
- Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan 52900, Israel; Department of Psychology, Bar-Ilan University, Ramat-Gan 52900, Israel.
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Examining implicit procedural learning in tetraplegia using an oculomotor serial reaction time task. PLoS One 2020; 15:e0232124. [PMID: 32324808 PMCID: PMC7179886 DOI: 10.1371/journal.pone.0232124] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/07/2020] [Indexed: 11/19/2022] Open
Abstract
Background and objective Clinical observations indicate that implicit procedural learning, a central component of physical and psychosocial rehabilitation, is impeded following spinal cord injury. In accordance, previous research has revealed a specific deficit in implicit sequence learning among individuals with paraplegia using a standard, manual version of the serial reaction time task. To extend these findings and shed light on the underlying sources of potential spinal cord injury-related deficits in sequence learning, we used an ocular activated serial reaction time task to compare sequence learning performance between individuals with tetraplegia and healthy controls. Participants and measures Twelve participants with spinal cord injury in C5-T1 were compared to 12 matched control participants on measures derived from an ocular activated serial reaction time task. Depression and additional cognitive measures were assessed to explore the source and specificity of potential sequence learning deficits. Results Like controls, and in contrast with previous findings in paraplegia, the spinal cord injury group showed intact implicit sequence learning, evidenced by declining reaction times and improved anticipation over the first six blocks of the serial reaction time task, and an advantage for the initial learning sequence over a novel interference sequence. Conclusions The ocular activated serial reaction time task elicited a performance pattern similar to standard motor versions, such that participants with tetraplegia demonstrated unimpaired sequence learning. This suggests that previously reported implicit sequence learning deficits in spinal cord injury directly involved motor functioning rather than cognitive aspects of the task, and that the ocular activated sequence learning task could be a valid alternative for assessing implicit sequence learning in populations that cannot perform spinal-cord dependent motor tasks. Implications for post-spinal cord injury rehabilitation and adjustment are discussed.
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Anticipation of wheelchair and rollerblade actions in spinal cord injured people, rollerbladers, and physiotherapists. PLoS One 2019; 14:e0213838. [PMID: 30875399 PMCID: PMC6420014 DOI: 10.1371/journal.pone.0213838] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 03/03/2019] [Indexed: 01/24/2023] Open
Abstract
Embodied Cognition Theories (ECT) postulate that higher-order cognition is heavily influenced by sensorimotor signals. We explored the active role of somatosensory afferents and motor efferents in modulating the perception of actions in people who have suffered a massive body-brain disconnection because of spinal cord injury (SCI), which leads to sensory-motor loss below the lesion. We assessed whether the habitual use of a wheelchair enhances the capacity to anticipate the endings of tool-related actions, with respect to actions that have become impossible. In a Temporal Occlusion task, three groups of participants (paraplegics, rollerbladers and physiotherapists) observed two sets of videos depicting an actor who attempted to climb onto a platform using a wheelchair or rollerblades. Three different outcomes were possible, namely: a) success (the actor went up the step); b) fail (the actor stopped before the step without going up) and c) fall (the actor fell without going up). Each video set comprised 5 different durations increasing in complexity: in the shortest (600ms) only preparatory body movements were shown and in the longest (3000ms) the complete action was shown. The participants were requested to anticipate the outcome (success, fail, fall). The main result showed that the SCI group performed better with the wheelchair videos and poorer with rollerblade videos than both groups, even if the physiotherapists group never used rollerblades. In line with the ECT, this suggests that the action anticipation skills are not only influenced by motor expertise, but also by motor connection.
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Fassett HJ, Turco CV, El-Sayes J, Nelson AJ. Alterations in Motor Cortical Representation of Muscles Following Incomplete Spinal Cord Injury in Humans. Brain Sci 2018; 8:E225. [PMID: 30558361 PMCID: PMC6316395 DOI: 10.3390/brainsci8120225] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/07/2018] [Accepted: 12/14/2018] [Indexed: 12/03/2022] Open
Abstract
(1) Background: The primary motor cortex (M1) experiences reorganization following spinal cord injury (SCI). However, there is a paucity of research comparing bilateral M1 organization in SCI and questions remain to be answered. We explored the presence of somatotopy within the M1 representation of arm muscles, and determined whether anatomical shifts in these representations occur, and investigated the symmetry in organization between the two hemispheres.; (2) Methods: Transcranial magnetic stimulation (TMS) was used to map the representation of the biceps, flexor carpi radialis and abductor pollicis brevis (APB) bilaterally in nine individuals with chronic incomplete cervical spinal cord injury and nine aged- and handed-matched uninjured controls. TMS was delivered over a 6 × 5 point grid that encompassed M1 using an intensity specific to the resting motor threshold for each muscle tested.; (3) Results: Results indicate that, compared to controls, muscle representations in SCI are shifted medially but preserve a general somatotopic arrangement, and that territory dedicated to the APB muscle is greater.; (4) Conclusions: These findings demonstrate differences in the organization of M1 between able-bodied controls and those with incomplete cervical SCI. This altered organization may have future implications in understanding the functional deficits observed in SCI and rehabilitation techniques aimed at restoring function.
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Affiliation(s)
- Hunter J Fassett
- Department of Kinesiology, McMaster University, Hamilton, ON L8S 4L8, Canada.
| | - Claudia V Turco
- Department of Kinesiology, McMaster University, Hamilton, ON L8S 4L8, Canada.
| | - Jenin El-Sayes
- Department of Kinesiology, McMaster University, Hamilton, ON L8S 4L8, Canada.
| | - Aimee J Nelson
- Department of Kinesiology, McMaster University, Hamilton, ON L8S 4L8, Canada.
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Woelfel JR, Dudley-Javoroski S, Shields RK. Precision Physical Therapy: Exercise, the Epigenome, and the Heritability of Environmentally Modified Traits. Phys Ther 2018; 98:946-952. [PMID: 30388254 PMCID: PMC6185994 DOI: 10.1093/ptj/pzy092] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/12/2018] [Indexed: 12/14/2022]
Abstract
One of the newest frontiers of physical therapy is the field of epigenetics, which examines how pervasive environmental factors such as exercise regulate the expression of genes. The epigenome may be one of the most powerful systems through which exercise exerts its beneficial effects on health and longevity. Large epidemiology studies show that individuals who regularly exercise demonstrate a lower "epigenetic age," experience fewer metabolic diseases, and enjoy greater longevity. However, the dose, mode, intensity, and duration of exercise required to achieve a healthy epigenetic profile is unknown. As experts in exercise prescription, physical therapists are ideally suited to contribute to the discovery of this dose-response relationship. This perspective makes a case for the genesis of "precision physical therapy," which capitalizes on epigenetic discoveries to optimize exercise-based interventions. Summarized here is the emerging body of knowledge supporting epigenetic adaptations to exercise in humans, including the intriguing possibility that these environmentally modified traits could be passed down to offspring. In the future, it is likely that epigenetic data will enhance our understanding of individual disease risk and individual response to prescribed exercise. The profession of physical therapy must be alert to new epigenetic knowledge that can enhance the specificity and efficacy of movement-based treatments.
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Affiliation(s)
- Jessica R Woelfel
- Department of Emergency Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Shauna Dudley-Javoroski
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa
| | - Richard K Shields
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, 1–252 Medical Education Building, University of Iowa, Iowa City, IA 52252 (USA),Address all correspondence to Dr Shields at:
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Doyon J, Gabitov E, Vahdat S, Lungu O, Boutin A. Current issues related to motor sequence learning in humans. Curr Opin Behav Sci 2018. [DOI: 10.1016/j.cobeha.2017.11.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Waltzman D, Madore M, McNerney MW, Durazzo TC, Bhat JV, Yesavage J, Adamson MM, Furst AJ. Preliminary Investigation of Sex Differences in Procedural Skill Learning in Veterans with Co-Morbidities. ACTA ACUST UNITED AC 2017. [DOI: 10.4236/jbbs.2017.78024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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