Elsevier

World Neurosurgery

Volume 107, November 2017, Pages 1045.e5-1045.e8
World Neurosurgery

Case Report
Preservation of Motor Function After Resection of Lower-Grade Glioma at the Precentral Gyrus and Prediction by Presurgical Functional Magnetic Resonance Imaging and Magnetoencephalography

https://doi.org/10.1016/j.wneu.2017.07.152Get rights and content

Background

Intra-axial brain tumors located at anatomically eloquent areas are challenging conditions. On one hand, it is often difficult to pursue maximum extent of resection of tumor in these locations. On the other hand, neuroplasticity occurs in some patients with low-grade glioma, and the primary neural functions are known to sometimes shift from conventional “eloquent cortices.”

Case Description

In a patient with a lower-grade glioma located at the precentral gyrus, shift of primary motor function from the precentral gyrus to the postcentral gyrus was detected on magnetoencephalography and functional magnetic resonance imaging. Aggressive removal of the pathologic precentral gyrus was accomplished via awake craniotomy without causing obvious motor function deficit.

Conclusions

This case highlights the importance of preoperative multimodal neurophysiologic imaging in patients with low-grade gliomas in eloquent areas.

Introduction

Increasing evidence is accumulating that the extent of resection for World Health Organization grade II and III gliomas is a significant prognostic factor for patients,1, 2, 3, 4 and awake craniotomy is frequently used to push the limit of the extent of resection, while avoiding postoperative neurologic declines.3, 4, 5 Nonetheless, surgeons and patients alike become hesitant to undertake aggressive removal of the tumor if the tumor is located in anatomically eloquent areas. The outcome of aggressive resection cannot be predicted during awake surgery, and methods that can provide a comprehensive understanding of the risks of aggressive tumor removal are needed to choose the optimal treatment strategy. As neuroplasticity remains in patients with low-grade glioma (LGG), primary neural functions are known to sometimes shift from conventional “eloquent cortices.” Previous reports have shown that lesions that were unremovable at initial surgery are sometimes removable later as a result of neuroplasticity.3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 These facts emphasize the importance of taking neuroplasticity into account when managing patients with LGG. In the present case, we detected a shift in primary motor function from the precentral gyrus to the postcentral gyrus on magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) in a patient with a lower-grade glioma and were able to achieve aggressive removal of the pathologic precentral gyrus without causing obvious motor function deficit.

Section snippets

Presentation to Reoperation

An intra-axial mass lesion was discovered at the right precentral gyrus in a 32-year-old Japanese woman during diagnostic work-up for a left-sided convulsive seizure attack. Despite the lesion completely residing at the precentral gyrus, the patient did not present with any neurologic deficits, including motor weakness. The lesion was nonenhancing on gadolinium-enhanced magnetic resonance imaging (MRI) and hyperintense on T2-weighted MRI. A biopsy specimen of the lesion was obtained under a

Discussion

Management of LGG is challenging in the field of surgical neuro-oncology. As these tumors tend to slowly evolve and often manifest with few neurologic symptoms at disease diagnosis, preoperative assessment should be performed from both oncologic and neurofunctional perspectives. Functional plasticity of the brain can be expected in some patients with LGGs,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 in which case primary neural functions, such as motor and sensory functions and language, are processes

Conclusions

From a clinical perspective, this case illustrates the importance of preoperative multimodal neurophysiologic functional assessment. As the expected neurologic deficit associated with tumor removal was hemiparesis or weakness of the left hand, the patient showed substantial courage in agreeing to surgical removal of the lesion via awake craniotomy. However, the objective information presented by preoperative MEG and fMRI indicating that neuroplasticity had occurred in the patient had a great

References (19)

  • T. Ius et al.

    Evidence for potentials and limitations of brain plasticity using an atlas of functional resectability of WHO grade II gliomas: towards a “minimal common brain.”

    Neuroimage

    (2011)
  • M.S. Berger

    Editorial: Low-grade gliomas

    J Neurosurg

    (2013)
  • J.S. Smith et al.

    Role of extent of resection in the long-term outcome of low-grade hemispheric gliomas

    J Clin Oncol

    (2008)
  • H. Duffau et al.

    New concepts in the management of diffuse low-grade glioma: proposal of a multistage and individualized therapeutic approach

    Neuro Oncol

    (2015)
  • H. Duffau et al.

    Contribution of intraoperative electrical stimulations in surgery of low grade gliomas: a comparative study between two series without (1985-96) and with (1996-2003) functional mapping in the same institution

    J Neurol Neurosurg Psychiatry

    (2005)
  • P.C. De Witt Hamer et al.

    Impact of intraoperative stimulation brain mapping on glioma surgery outcome: a meta-analysis

    J Clin Oncol

    (2012)
  • H. Duffau et al.

    Long term reshaping of language, sensory, and motor maps after glioma resection: a new parameter to integrate in the surgical strategy

    J Neurol Neurosurg Psychiatry

    (2002)
  • E. Caverzasi et al.

    Identifying preoperative language tracts and predicting postoperative functional recovery using HARDI q-ball fiber tractography in patients with gliomas

    J Neurosurg

    (2016)
  • M. Fujii et al.

    Intraoperative subcortical mapping of a language-associated deep frontal tract connecting the superior frontal gyrus to Broca's area in the dominant hemisphere of patients with glioma

    J Neurosurg

    (2015)
There are more references available in the full text version of this article.

Cited by (5)

Supplementary digital content available online.

Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

View full text