Background And Purpose: Diffusion tensor imaging (DTI) was introduced as a good technique to evaluate structural abnormalities in the white matter. In this study, we used DTI to examine anisotropic changes of the pyramidal tracts displaced by chronic subdural hematoma (CSDH).
Materials And Methods: Twenty-six patients with unilateral CSDH underwent DTI before and after surgery. We measured fractional anisotropy (FA) values in pyramidal tracts of bilateral cerebral peduncles and calculated the ratio of the FA value on the lesion side to that on the contralateral side (FA ratio) and compared the ratios with motor weakness. Moreover, the relationships between FA ratios and clinical factors such as age, sex, midline shift, interval from trauma, and hematoma attenuation on CT were evaluated.
Results: FA values of pyramidal tracts on the lesion side were significantly lower than those on the contralateral side (0.66 +/- 0.07 versus 0.74 +/- 0.05, P < .0001). The FA ratio was correlated to the severity of motor weakness (r(2) = 0.32, P = .002). FA ratios after surgery improved significantly compared with those before surgery (0.96 +/- 0.08 versus 0.89 +/- 0.07, P = .0004). Intervals from trauma and the midline shift were significantly associated with decreased FA ratios (P = .0008 and P = .037).
Conclusions: In patients with CSDH, a reversible decrease of FA in the affected pyramidal tract on DTI was correlated to motor weakness. These anisotropic changes were considered to be caused by a reversible distortion of neuron fibers and vasogenic edema due to the hematoma.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8118822 | PMC |
http://dx.doi.org/10.3174/ajnr.A1001 | DOI Listing |
J Neuroeng Rehabil
January 2025
Shirley Ryan AbilityLab, Chicago, IL, USA.
There is a consensus that motor recovery post-stroke primarily depends on the degree of the initial connectivity of the ipsilesional corticospinal tract (CST). Indeed, if the residual CST connectivity is sufficient to convey motor commands, the neuromotor system continues to use the CST predominantly, and motor function recovers up to 80%. In contrast, if the residual CST connectivity is insufficient, hand/arm dexterity barely recovers, even as the phases of stroke progress.
View Article and Find Full Text PDFEur J Neurosci
January 2025
Department of Kinesiology, Trent University, Peterborough, ON, Canada.
Previous research on resting muscles has shown that inter-pulse interval (IPI) duration influences transcranial magnetic stimulation (TMS) responses, which can introduce serious confounding variables into investigations if not accounted for. However, it is far less clear how IPI influences TMS responses in active muscles. Thus, the purpose of this study was to examine the relationship between IPI and corticospinal excitability during submaximal isometric elbow flexion.
View Article and Find Full Text PDFNeuropathology
January 2025
Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan.
The degeneration of pyramidal tracts has been reported in frontotemporal lobar degeneration with TDP-43 (TAR DNA-binding protein 43) pathology (FTLD-TDP) type C. Herein, we examined the detailed pathology of the primary motor area and pyramidal tracts in the central nervous system in four autopsy cases of FTLD-TDP type C, all of which were diagnosed by neuropathological, biochemical, and genomic analyses. Three patients showed right dominant atrophy of the frontal and temporal lobes, while the other patient showed left dominant atrophy.
View Article and Find Full Text PDFExp Brain Res
January 2025
Faculty of Sport, Technology and Health Sciences, St. Mary's University, Twickenham, Middlesex, UK.
The aim of this study was to assess if ischaemic preconditioning (IPC) can reduce pain perception and enhance corticospinal excitability during voluntary contractions. In a randomised, within-subject design, healthy participants took part in three experimental visits after a familiarisation session. Measures of pressure pain threshold (PPT), maximum voluntary isometric force, voluntary activation, resting twitch force, corticospinal excitability and corticospinal inhibition were performed before and ≥10 min after either, unilateral IPC on the right leg (3 × 5 min); a sham protocol (3 × 1 min); or a control (no occlusion).
View Article and Find Full Text PDFSci Rep
January 2025
Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Chicago, IL, 60611, USA.
Corticospinal motor neurons (CSMN), located in the motor cortex of the brain, are one of the key components of the motor neuron circuitry. They are in part responsible for the initiation and modulation of voluntary movement, and their degeneration is the hallmark for numerous diseases, such as amyotrophic lateral sclerosis (ALS), hereditary spastic paraplegia, and primary lateral sclerosis. Cortical hyperexcitation followed by in-excitability suggests the early involvement of cortical dysfunction in ALS pathology.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!