Corticospinal tract atrophy and motor fMRI predict motor preservation after functional cerebral hemispherectomy

Wang, Anthony; Ibrahim, George M.; Poliakov, Andrew; Wang, Page I.; Fallah, Aria; Mathern, Gary W.; Buckley, Robert T.; Collins, Kelly L.; Weil, Alexander G.; Shurtleff, Hillary A.; Warner, Molly H.; Perez, Francisco A.; Shaw, Dennis; Wright, Jason N.; Saneto, Russell P.; Novotny, Edward J.; Lee, Amy; Browd, Samuel R.; Ojemann, Jeffrey G.

doi:10.3171/2017.7.peds17137

Cited by 16 publications

(16 citation statements)

References 37 publications

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“…Motor decline after surgery is a major concern for clinicians and families. To localize motor cortex activation, most studies utilized finger/hand or foot tapping tasks [89,[106][107][108][109]. Motor cortex activation can be achieved using passive (under sedation or in paretic extremities) or active tasks where the patient is awake.…”

Section: Motor Area Evaluationmentioning

confidence: 99%

Utility of MRI, PET, and ictal SPECT in presurgical evaluation of non-lesional pediatric epilepsy

Juhász

John

2020

Seizure

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Children with epilepsy and normal structural MRI pose a particular challenge in localization of epileptic foci for surgical resection. Many of these patients have subtle structural lesions such as mild cortical dysplasia that can be missed by conventional MRI but may become detectable by optimized and advanced MRI acquisitions and post-processing. Specificity of objective analytic techniques such as voxel-based morphometry remains an issue. Combination of MRI with functional imaging approaches can improve the accuracy of detecting epileptogenic brain regions. Analysis of glucose positron emission tomography (PET) combined with high-resolution MRI can optimize detection of hypometabolic cortex associated with subtle cortical malformations and can also enhance presurgical evaluation in children with epileptic spasms. Additional PET tracers may detect subtle epileptogenic lesions and cortex with enhanced specificity in carefully selected subgroups with various etiologies; e.g., increased tryptophan uptake can identify epileptogenic cortical dysplasia in the interictal state. Subtraction ictal SPECT can be also useful to delineate ictal foci in those with non-localizing PET or after failed surgical resection. Presurgical delineation of language and motor cortex and the corresponding white matter tracts is increasingly reliable by functional MRI and DTI techniques; with careful preparation, these can be useful even in young and sedated children. While evidence-based pediatric guidelines are still lacking, the data accumulated in the last decade strongly indicate that multimodal imaging with combined analysis of MRI, PET, and/or ictal SPECT data can optimize the detection of subtle epileptogenic lesions and facilitate seizure-free outcome while minimizing the postsurgical functional deficit in children with normal conventional MRI.

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Section: Motor Area Evaluationmentioning

confidence: 99%

Utility of MRI, PET, and ictal SPECT in presurgical evaluation of non-lesional pediatric epilepsy

Juhász

John

2020

Seizure

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“…In practice, Case 2 did not worsen: quantifying the lateralization of the motor network, DTI and fMRI revealed a moderate lateralization. It is possible that the motor pathways of the intact hemisphere contributed strongly to the paretic arm already before surgery, and that disconnective surgery might have facilitated ipsilateral motor control of limb function through disinhibition of the ipsilateral tract, as proposed by Wang et al ( 20 ). The patient suffered from a severe (multilobar) lesion at 6 months: this early lesion might have triggered compensatory mechanisms in the healthy hemisphere and this would explain the effective reorganization observed even if surgery occurred in adulthood.…”

Section: Discussionmentioning

confidence: 98%

“…Similar findings were observed also by Pilato et al ( 21 ) and Staudt et al ( 6 ). Moreover, as suggested by Wang et al the ipsilateral pathway might have been partially inhibited by the activity of the affected hemisphere in the preoperative state, and the surgical disconnection might have unmasked the contribution of the ipsilateral tract ( 20 ). In this case, fMRI activations were less consistent with DTI lateralization.…”

Section: Discussionmentioning

confidence: 99%

“…fMRI and DTI were useful non-invasive tools to investigate the mechanisms of motor plasticity in four patients candidate to disconnection surgery ( 20 , 39 , 40 ). The results of our small sample show that the brain motor network has a redundancy of pathways (ipsilatereal and contralateral CST, primary motor cortex and associative motor areas such as SMA) which can be used as compensatory mechanisms.…”

Section: Discussionmentioning

confidence: 99%

“…In particular, a DTI study with 102 patients showed that the CST asymmetry observed with a visual analysis of directionally-encoded color FA maps was useful to predict hand function (i.e., grasping ability) after hemidisconnection ( 19 ). A recent study employing fMRI and DTI showed that sensorimotor fMRI and colored FA-DTI maps could predict severe motor decline in a series of 25 patients ( 20 ). Only a few studies have investigated patients before and after hemispherectomy.…”

Section: Introductionmentioning

confidence: 99%

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Tracking the Re-organization of Motor Functions After Disconnective Surgery: A Longitudinal fMRI and DTI Study

et al. 2018

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Objective: Mechanisms of motor plasticity are critical to maintain motor functions after cerebral damage. This study explores the mechanisms of motor reorganization occurring before and after surgery in four patients with drug-refractory epilepsy candidate to disconnective surgery.Methods: We studied four patients with early damage, who underwent tailored hemispheric surgery in adulthood, removing the cortical motor areas and disconnecting the corticospinal tract (CST) from the affected hemisphere. Motor functions were assessed clinically, with functional MRI (fMRI) tasks of arm and leg movement and Diffusion Tensor Imaging (DTI) before and after surgery with assessments of up to 3 years. Quantifications of fMRI motor activations and DTI fractional anisotropy (FA) color maps were performed to assess the lateralization of motor network. We hypothesized that lateralization of motor circuits assessed preoperatively with fMRI and DTI was useful to evaluate the motor outcome in these patients.Results: In two cases preoperative DTI-tractography did not reconstruct the CST, and FA-maps were strongly asymmetric. In the other two cases, the affected CST appeared reduced compared to the contralateral one, with modest asymmetry in the FA-maps. fMRI showed different degrees of lateralization of the motor network and the SMA of the intact hemisphere was mostly engaged in all cases. After surgery, patients with a strongly lateralized motor network showed a stable performance. By contrast, a patient with a more bilateral pattern showed worsening of the upper limb function. For all cases, fMRI activations shifted to the intact hemisphere. Structural alterations of motor circuits, observed with FA values, continued beyond 1 year after surgery.Conclusion: In our case series fMRI and DTI could track the longitudinal reorganization of motor functions. In these four patients the more the paretic limbs recruited the intact hemisphere in primary motor and associative areas, the greater the chances were of maintaining elementary motor functions after adult surgery. In particular, DTI-tractography and quantification of FA-maps were useful to assess the lateralization of motor network. In these cases reorganization of motor connectivity continued for long time periods after surgery.

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Determinants of Functional Outcome after Pediatric Hemispherotomy

Ramantani,

Cserpan,

Tisdall

et al. 2023

Annals of Neurology

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ObjectiveWe aimed to evaluate determinants of functional outcome after pediatric hemispherotomy in a large and recent multicenter cohort.MethodsWe retrospectively investigated the functional outcomes of 455 children who underwent hemispherotomy in five epilepsy centers in 2000–2016. We identified determinants of unaided walking, voluntary grasping with the hemiplegic hand, and speaking through Bayesian multivariable regression modeling using missing data imputation.Results75% of children were seizure‐free, and 44% stopped antiseizure medication at a 5.1‐year mean follow‐up (range 1–17.1). 77% of children could walk unaided, 8% could grasp voluntarily, and 68% could speak at the last follow‐up. Children were unlikely to walk when they had contralateral MRI abnormalities (40/73; p = 0.04), recurrent seizures following hemispherotomy (62/109; p = 0.04), and moderately (50/61; p = 0.03) or severely impaired (127/199; p = 0.001) postsurgical intellectual functioning, but were likely to walk when they were older at outcome determination (p = 0.01). Children were unlikely to grasp voluntarily with the hand contralateral to surgery when they had Rasmussen encephalitis (0/61; p = 0.001) or Sturge–Weber syndrome (0/32; p = 0.007). Children were unlikely to speak when they had contralateral MRI abnormalities (30/69; p = 0.002) and longer epilepsy duration (p = 0.01), but likely to speak when they had Sturge–Weber syndrome (29/35; p = 0.01), were older at surgery (p = 0.04) and older at outcome determination (p < 0.001).InterpretationEtiology and bilaterality of structural brain abnormalities were key determinants of functional outcome after hemispherotomy. Longer epilepsy duration affected language outcomes. Not surprisingly, walking and talking ability increased with older age at outcome evaluation.This article is protected by copyright. All rights reserved.

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Corticospinal tract atrophy and motor fMRI predict motor preservation after functional cerebral hemispherectomy

Cited by 16 publications

References 37 publications

Utility of MRI, PET, and ictal SPECT in presurgical evaluation of non-lesional pediatric epilepsy

Utility of MRI, PET, and ictal SPECT in presurgical evaluation of non-lesional pediatric epilepsy

Tracking the Re-organization of Motor Functions After Disconnective Surgery: A Longitudinal fMRI and DTI Study

Determinants of Functional Outcome after Pediatric Hemispherotomy

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