Demystifying white matter injury in the unconscious patients with diffusion tensor imaging

 

 Permissions and Reprints

Background: Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) provide a noninvasive window to study the neural connectivity and reconstruct the tracts. Detection of white matter injury (WMI) by DTT is a recent application being used in stroke, diffuse axonal injury, and neurodegenerative disorders. Fiber tracking in patients with brain hemorrhage can detect loss of fibers and anatomical disruption of the tracts, which can be useful in the prognostication of patient outcome. Materials and Methods: DTI and fiber tracking was done in four patients admitted at Fujita Health University Banbuntane Hospital, Japan, with decreased consciousness following brain hemorrhage (3 patients with aneurysmal subarachnoid hemorrhage and one patient with bifrontal hemorrhage), and WMI was analyzed. We also reviewed the literature on tractography in patients with brain hemorrhage and its correlation with consciousness. Results: We found significant frontal WMI in the form of thinning and anatomical disruption in all four cases. The frontal white matter tracts form an important component of the limbic system and ascending reticular activating system and frontal WMI correlated with the poor conscious level and cognitive dysfunction. Structural damage to the fiber tracts demonstrated as thinning, reduction in the volume or absence on tractography with corresponding reduction in the mean fractional anisotropy values in the frontal white matter of the affected side. Conclusion: DTI can be useful as a critical tool for revealing the anatomical basis for the cognitive dysfunction and unconsciousness and can be possibly used to prognosticate patient recovery. Early detection of WMI by DTI can also help in tailored rehabilitation. The authors believe that DTT could have a crucial role in the future for detecting structural changes which lead to cognitive dysfunction and further studies are needed to arrive at a specific protocol for detecting WMI.

Financial support and sponsorship

Nil.

Publication History

Received: 12 February 2020

Accepted: 20 March 2020

Article published online:
16 August 2022

© 2020. Asian Congress of Neurological Surgeons. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

Thieme Medical and Scientific Publishers Pvt. Ltd.
A-12, 2nd Floor, Sector 2, Noida-201301 UP, India

• References

• 1 Shah A, Jhawar SS, Goel A. Analysis of the anatomy of the Papez circuit and adjoining limbic system by fiber dissection techniques. J Clin Neurosci 2012;19:289-98.
• 2 Kamali A, Zhang CC, Riascos RF, Tandon N, Bonafante-Mejia EE, Patel R, et al. Diffusion tensor tractography of the mammillothalamic tract in the human brain using a high spatial resolution DTI technique. Sci Rep 2018;8:5229.
• 3 Berger JR. Memory and the mammillothalamic tract. AJNR Am J Neuroradiol 2004;25:906-7.
• 4 Choi SH, Kim YB, Paek SH, Cho ZH. Papez circuit observed byin vivo human brain with 7.0T MRI super-resolution track density imaging and track tracing. Front Neuroanat 2019;13:17.
• 5 Jang SH, Chang CH, Jung YJ, Seo YS. Change of ascending reticular activating system with recovery from vegetative state to minimally conscious state in a stroke patient. Medicine (Baltimore) 2016;95:e5234.
• 6 Jang S, Lee H. Change of ascending reticular activating system following shunt operation for hydrocephalus in a subarachnoid hemorrhage Patient. J Neurol Surg A Cent Eur Neurosurg 2019;80:62-6.
• 7 Jang SH, Kim HS. Aneurysmal subarachnoid hemorrhage causes injury of the ascending reticular activating system: Relation to consciousness. AJNR Am J Neuroradiol 2015;36:667-71.
• 8 Yeo SS, Chang PH, Jang SH. The ascending reticular activating system from pontine reticular formation to the thalamus in the human brain. Front Hum Neurosci 2013;7:416.
• 9 Ordóñez-Rubiano EG, Johnson J, Enciso-Olivera CO, Marín-Muñoz JH, Cortes-Lozano W, Baquero-Herrera PE, et al. Reconstruction of the ascending reticular activating system with diffusion tensor tractography in patients with a disorder of consciousness after traumatic brain injury. Cureus 2017;9:e1723.
• 10 Reijmer YD, van den Heerik MS, Heinen R, Leemans A, Hendrikse J, de Vis JB, et al. Microstructural white matter abnormalities and cognitive impairment after aneurysmal subarachnoid hemorrhage. Stroke 2018;49:2040-5.
• 11 Tao C, Hu X, Li H, You C. White matter injury after intracerebral hemorrhage: pathophysiology and therapeutic strategies. Front Hum Neurosci 2017;11:422.
• 12 Jang SH, Choi BY, Kim SH, Chang CH, Jung YJ, Kwon HG. Injury of the mammillothalamic tract in patients with subarachnoid haemorrhage: A retrospective diffusion tensor imaging study. BMJ Open 2014;4:e005613.
• 13 Jang SH, Yeo SS. Injury of the precommissural fornix in a patient with subarachnoid hemorrhage: A case report. J Stroke Cerebrovasc Dis 2018;27:e98-101.
• 14 Jang SH, Seo JP. Multiple injuries of the ascending reticular activating system in a stroke patient: A diffusion tensor tractography study. Neural Regen Res 2017;12:151-2.
• 15 Hong JH, Choi BY, Chang CH, Kim SH, Jung YJ, Byun WM, et al. Injuries of the cingulum and fornix after rupture of an anterior communicating artery aneurysm: A diffusion tensor tractography study. Neurosurgery 2012;70:819-23.
• 16 Jang SH, Yeo SS. Injury of the Papez circuit in a patient with provoked confabulation following subarachnoid hemorrhage: A diffusion tensor tractography study. Acta Neurol Belg 2016;116:655-8.
• 17 Tsung PC, Sung SK, Son DW, Lee SW, Song GS. Prediction of motor function outcome in patients with brain injury using computed tomography and diffusion tensor image. Nerve 2019;5:1-6.