Broca area high-grade glioma

Introduction

Historically, the Broca area has been defined as residing primarily within the pars triangularis of the inferior frontal gyrus or frontal operculum on the dominant hemisphere. ^, The methods of identifying this area radiographically primarily involves functional magnetic resonance imaging (fMRI), in which neurovascular coupling allows the identification of flow changes in conjunction with neuronal activity. The difficulty with fMRI is that it is prone to false positives and false negatives, does not identify critical threshold of functions, and can be less sensitive and/or specific in tumor-infiltrated and/or edematous areas that is common for gliomas. The direct method of identifying these areas is awake brain mapping with direct electrical stimulation, whereby electrical stimulation impairs normal neurologic firing to identify functional processes. In this chapter, we present a case of a high-grade glioma in close proximity to the inferior frontal gyrus, which has historically been identified as the Broca area.

Example case

Chief complaint: speaking problems and confusion

History of present illness

A 59-year-old, right-handed woman with a history of hypertension, hyperlipidemia, and anxiety presented with confusion and speaking problems. Her family states that over the past couple of months they have noted that she has become increasingly confused and with difficulty getting her words out. She was seen by a neurologist who ordered imaging that showed a large brain lesion ( Fig. 19.1 ).

Medications : Lisinopril, atorvastatin, sertraline.
Allergies : No known drug allergies.
Past medical and surgical history : Hypertension, hyperlipidemia, anxiety.
Family history : No history of intracranial malignancies.
Social history: Homemaker, no smoking or alcohol history.
Physical examination : Awake, alert, oriented to person, place, and time; Language: slowness in speech, dysarthria, intact naming and repetition; Cranial nerves II to XII intact; Right drift, moves all extremities with full strength.
Imaging : Chest/abdomen/pelvis imaging negative for primary malignancy.

	Jeffrey N. Bruce, MD, Columbia University, New York City, NY, United States	Chae-Yong Kim, MD, PhD, Seoul National University, Bundang Hospital, Seoul, South Korea	Ganesh Rao, MD, Baylor College of Medicine, Houston, TX, United States	Jinsong Wu, MD, PhD, Fudan University, Huashan Hospital, Shanghai, China
Preoperative
Additional tests requested	DTI fMRI Neuropsychological assessment	DTI Perfusion and diffusion MRI +/– fMRI PET	fMRI Neuropsychological assessment	DTI Task-based BOLD fMRI MRS Neuropsychological assessment
Surgical approach selected	Left frontal craniotomy with awake language and motor mapping	Left frontal craniotomy with 5-ALA	Left frontal craniotomy	Left frontal craniotomy with awake language and motor mapping with intraoperative MRI
Anatomic corridor	Left frontal over tumor	Left frontal	Left frontal above frontal sinus	Left frontal
Goal of surgery	Extensive resection of contrast and FLAIR with functional preservation	Attempted gross total resection	Diagnosis because of insula involvement and maximal safe resection	Maximal safe resection of enhancing component
Perioperative
Positioning	Left supine with slight right rotation	Left supine with 5-degree right rotation	Left supine	Left supine with 30-degree right rotation
Surgical equipment	Surgical navigation IOM (ECoG) Brain stimulator Ultrasound Ultrasonic aspirator Surgical microscope	Surgical navigation IOM Ultrasound Surgical microscope with 5-ALA Ultrasonic aspirator	Surgical navigation Ultrasound	Surgical navigation IOM Brain stimulator Ultrasonic aspirator Intraoperative MRI
Medications	Steroids Antiepileptics 5-ALA or Fluorescein	Antiepileptics	Steroids	Steroids Antiepileptics
Anatomic considerations	Sylvian fissure, speech and motor areas, lateral ventricle	Corpus callosum, MCA	Sphenoid wing, frontal sinus, sagittal sinus, Broca area, lateral ventricles, ACA	Coronal suture, IFG, orbital gyrus, frontal horn lateral ventricle, caudate head, fornix, ventral striatal pallidum, anterior perforated substance, mesial basal frontal cortex, genu of corpus callosum, prefrontal veins and arteries
Complications feared with approach chosen	Language dysfunction, motor deficit	Language dysfunction	Language dysfunction, ACA injury	Language dysfunction, motor deficit, cognitive dysfunction
Intraoperative
Anesthesia	Asleep-awake-asleep	General	General	Awake (MAC)
Skin incision	Bicoronal	Bicoronal	Modified bicoronal	Bicoronal linear
Bone opening	Left frontal near sagittal sinus	Left frontal	Left frontal above frontal sinus	Left frontal
Brain exposure	Left SFG, MFG, IFG	Left frontal	Left frontal pole	Left SFG, MFG, IFG
Method of resection	Local anesthetic application, craniotomy planning based on navigation, large left frontal craniotomy to encompass lesion and Sylvian fissure, cruciate dural opening over lesion, patient awoken, ECoG grids, awake speech and motor mapping, outline tumor with navigation, corticectomy in negative mapping areas starting lateral to tumor, dissect posteriorly and leave medial portion for last, extend resection to skull base and into frontal horn of lateral ventricle, debulk tumor with ultrasonic aspirator, dissect from critical white matter tracts identified during mapping, ultrasound to guide further resection, resect fluorescing tissue, watertight dural closure	Craniotomy based on navigation, open dura, delineate tumor margins with navigation and ultrasound, attempt en bloc, inspect cavity with 5-ALA and ultrasound	Semibicoronal incision taken down to just temporalis fascia, craniotomy ipsilateral to sagittal sinus, ultrasound to locate hyperechoic component, intralesional resection, remove as much of the suckable portion of tumor as possible, no attempt at en bloc or supratotal resection	Craniotomy based on navigation, dural opening, identify and protect the Broca area, resection from lateral fissure to intercerebral fissure to 2 cm in front of coronal suture and close to the frontal horn of the lateral ventricle, attempt to avoid opening lateral ventricle, removal of the prefrontal lobe en bloc with ultrasonic aspirator, removal of deep portion of residual tumor guided by navigation, continuous MEP, intraoperative MRI to guide further resection, watertight dural closure
Complication avoidance	Cortical and subcortical mapping, leave medial portion for last, fluorescence, ultrasound	Attempt en bloc, 5-ALA and ultrasound to guide resection	Ultrasound, limiting resection to suckable component	Cortical and subcortical mapping, continuous MEP, obey anatomic boundaries, intraoperative MRI
Postoperative
Admission	ICU	ICU	Intermediate care	ICU
Postoperative complications feared	Language dysfunction, motor deficit, seizures	Language dysfunction	Language dysfunction, vascular injury	Language dysfunction, cognitive disorder
Follow-up testing	MRI within 48 hours after surgery	MRI within 48 hours after surgery	MRI within 24 hours after surgery Neuropsychological and speech assessment 3 days after surgery	Intraoperative MRI on completion of surgery or MRI within 72 hours after surgery
Follow-up visits	7 days after surgery	3–4 weeks after adjuvant therapy	7 days after surgery 1 month after surgery with MRI	1 month after surgery
Adjuvant therapies recommended
IDH status	Mutant–radiation/temozolomide Wild type–radiation/temozolomide	Mutant–radiation/temozolomide Wild type–radiation/temozolomide	Mutant–radiation/temozolomide Wild type–radiation/temozolomide	Mutant–radiation/temozolomide Wild type–radiation/temozolomide
MGMT status	Methylated–radiation/temozolomide Unmethylated–radiation/temozolomide	Methylated–radiation/temozolomide Unmethylated–radiation/temozolomide	Methylated–radiation/temozolomide Unmethylated–radiation/temozolomide	Methylated–radiation/temozolomide Unmethylated–radiation/temozolomide