Changes in fiber tract integrity and visual fields after anterior temporal lobectomy

McDonald, Colm; Hagler, Donald J.; Girard, Holly M.; Pung, Christopher J.; Ahmadi, Mazyar E.; Holland, Dominic; Patel, R.; Barba, David; Tecoma, Evelyn S.; Iragui, Vicente J.; Halgren, Eric; Dale, Anders M.

doi:10.1212/wnl.0b013e3181fb44db

Cited by 47 publications

(35 citation statements)

References 23 publications

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“…The direction of this relationship is unclear, however; it is possible that injury of the fornicial WM results in subsequent damage to the hippocampus. In studies of anterior temporal lobectomy patients, long-term changes in fornicial DTI values were consistent with myelin degradation [32, 33], although acute measures were more variable [34]. Studies of hippocampal volume and fornicial integrity in patients with mild cognitive impairment have confirmed that hippocampal volume loss is related to reduced integrity of the fornix [35, 36], although fornicial abnormalities with no concurrent hippocampal atrophy have been found in patients with early mild cognitive impairment [37].…”

Section: Discussionmentioning

confidence: 99%

Hippocampal volume is related to cognitive decline and fornicial diffusion measures in multiple sclerosis

Koenig

Sakaie

Lowe

et al. 2014

Magnetic Resonance Imaging

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Purpose To assess for associations between hippocampal atrophy and measures of cognitive function, hippocampal magnetization transfer ratio (MTR), and diffusion measures of the fornix, the largest efferent white matter tract from the hippocampus, in patients with multiple sclerosis (MS) and controls. Materials and Methods A total of 53 patients with MS and 20 age- and sex-matched healthy controls participated in cognitive testing and scanning including high spatial-resolution diffusion imaging and a T1-MPRAGE scan. Hippocampal volume and fornicial thickness measures were calculated and compared to mean values of fornicial transverse diffusivity, mean diffusivity, longitudinal diffusivity, fractional anisotropy, mean hippocampal MTR, and scores on measures of episodic memory, processing speed, and working memory tasks. Results In patients with MS, hippocampal volume was significantly related to fornicial diffusion measures (P < 7 × 10−4) and to measures of verbal (P = 0.030) and visual spatial (P = 0.004) episodic memory and a measure of information processing speed (P < 0.037). Discussion These results highlight the role of the hippocampus in cognitive dysfunction in patients with MS and suggest that measures of hippocampal atrophy could be used to capture aspects of disease progression.

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Section: Discussionmentioning

confidence: 99%

Hippocampal volume is related to cognitive decline and fornicial diffusion measures in multiple sclerosis

Koenig

Sakaie

Lowe

et al. 2014

Magnetic Resonance Imaging

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“…30,34,45 Acute compromise of the fiber tract integrity (e.g., due to hematoma) may be evident using FA within days of the event, 49 with further changes due to wallerian degeneration being observed within months. 30 It is noteworthy that the perilesional decreases in the QA values either deteriorated or stayed stable over the follow-up period and after the removal of the CM and associated hemorrhagic products. The susceptibility effects from the paramagnetic molecules, such as deoxyhemoglobin, are known to affect the quantitative results, leading to artifactual signal loss.…”

Section: Tractography-based Quantitative Data and Implicationsmentioning

confidence: 99%

Longitudinal evaluation of corticospinal tract in patients with resected brainstem cavernous malformations using high-definition fiber tractography and diffusion connectometry analysis: preliminary experience

Faraji¹,

Kumar²,

Jarbo

et al. 2015

JNS

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abbreviatioNs ADL = activities of daily living; CC = corpus callosum; CM = cavernous malformation; CN = cranial nerve; CST = corticospinal tract; DSI = diffusion spectrum imaging; DTI = diffusion tensor imaging; FDR = false discovery rate; HDFT = high-definition fiber tractography; ICH = intracerebral hemorrhage; QA = quantitative anisotropy; ROI = region of interest; SRS = stereotactic radiosurgery. obJect Brainstem cavernous malformations (CMs) are challenging due to a higher symptomatic hemorrhage rate and potential morbidity associated with their resection. The authors aimed to preoperatively define the relationship of CMs to the perilesional corticospinal tracts (CSTs) by obtaining qualitative and quantitative data using high-definition fiber tractography. These data were examined postoperatively by using longitudinal scans and in relation to patients' symptomatology. The extent of involvement of the CST was further evaluated longitudinally using the automated "diffusion connectometry" analysis. methods Fiber tractography was performed with DSI Studio using a quantitative anisotropy (QA)-based generalized deterministic tracking algorithm. Qualitatively, CST was classified as being "disrupted" and/or "displaced." Quantitative analysis involved obtaining mean QA values for the CST and its perilesional and nonperilesional segments. The contralateral CST was used for comparison. Diffusion connectometry analysis included comparison of patients' data with a template from 90 normal subjects. results Three patients (mean age 22 years) with symptomatic pontomesencephalic hemorrhagic CMs and varying degrees of hemiparesis were identified. The mean follow-up period was 37.3 months. Qualitatively, CST was partially disrupted and displaced in all. Direction of the displacement was different in each case and progressively improved corresponding with the patient's neurological status. No patient experienced neurological decline related to the resection. The perilesional mean QA percentage decreases supported tract disruption and decreased further over the follow-up period (Case 1, 26%-49%; Case 2, 35%-66%; and Case 3, 63%-78%). Diffusion connectometry demonstrated rostrocaudal involvement of the CST consistent with the quantitative data. coNclusioNs Hemorrhagic brainstem CMs can disrupt and displace perilesional white matter tracts with the latter occurring in unpredictable directions. This requires the use of tractography to accurately define their orientation to optimize surgical entry point, minimize morbidity, and enhance neurological outcomes. Observed anisotropy decreases in the perilesional segments are consistent with neural injury following hemorrhagic insults. A model using these values in different CST segments can be used to longitudinally monitor its craniocaudal integrity. Diffusion connectometry is a complementary approach providing longitudinal information on the rostrocaudal involvement of the CST.

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“…This compromise can be partly ascribed to Wallerian degeneration associated with the disconnected fiber tracts, as occurs in epilepsy patients receiving corpus callosotomy or temporal lobectomy (28)(29)(30). Wallerian degeneration may continue to develop along fiber tracts.…”

Section: Effect Of Surgical Defects and Implicationsmentioning

confidence: 99%

Effects of Surgery and Proton Therapy on Cerebral White Matter of Craniopharyngioma Patients

Hua

Ogg

et al. 2014

International Journal of Radiation Oncology*Biology*Physics

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Purpose-To determine the radiation dose-effect on the structural integrity of cerebral white matter in craniopharyngioma patients receiving surgery and proton therapy.Methods and Materials-Fifty-one patients (aged 2.1-19.3 years) with craniopharyngioma underwent surgery and proton therapy in a prospective therapeutic trial. Anatomical magnetic resonance images acquired after surgery but before proton therapy were inspected to identify white matter structures intersected by surgical corridors and catheter tracks. Longitudinal diffusion tensor imaging (DTI) was performed to measure microstructural integrity changes in cerebral white matter. Fractional anisotropy (FA) derived from DTI was statistically analyzed for 51 atlasbased white matter structures of the brain to determine radiation dose-effect. FA in surgeryaffected regions in the corpus callosum was compared to that in its intact counterpart to determine whether surgical defects affect radiation dose-effect.Results-Surgical defects were seen most frequently in the corpus callosum because of transcallosal resection of tumors and insertion of ventricular or cyst catheters. The longitudinal DTI data indicated reductions in FA 3 months after therapy, which was followed by a recovery in most white matter structures. A greater FA reduction was correlated with a higher radiation dose in 20 white matter structures, indicating a radiation dose-effect. The average FA in the surgery- Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. HHS Public Access Author Manuscript Author ManuscriptAuthor ManuscriptAuthor Manuscript affected regions before proton therapy was smaller (P =0.0001) than that in their non-surgery affected counterparts with more intensified subsequent reduction of FA (P=0.0083) after therapy, suggesting that surgery accentuated the radiation dose-effect.Conclusions-DTI data suggest that mild radiation dose-effects occur in patients with craniopharyngioma receiving surgery and proton therapy. Surgical defects present at the time of proton therapy appear to accentuate the radiation dose-effect longitudinally. This study supports consideration of pre-existing surgical defects and their locations in proton therapy planning and studies of treatment effect.

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Changes in fiber tract integrity and visual fields after anterior temporal lobectomy

Cited by 47 publications

References 23 publications

Hippocampal volume is related to cognitive decline and fornicial diffusion measures in multiple sclerosis

Hippocampal volume is related to cognitive decline and fornicial diffusion measures in multiple sclerosis

Longitudinal evaluation of corticospinal tract in patients with resected brainstem cavernous malformations using high-definition fiber tractography and diffusion connectometry analysis: preliminary experience

Effects of Surgery and Proton Therapy on Cerebral White Matter of Craniopharyngioma Patients

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