Broca area low-grade glioma

Introduction

The goal of achieving extensive resection for low-grade gliomas (LGGs) in eloquent regions is a relatively new paradigm, as many recent studies are now showing that observation and lesser resections are associated with poorer outcomes. Jakola et al. evaluated outcomes from a Norwegian population-based parallel cohort study where one hospital performed diagnostic biopsies followed by observation and another hospital advocated early resection. They found that estimated 5-year overall survival was 74% in the surgery cohort as compared with 60% in the biopsy and observation cohort. However, although surgery in the Broca region can be associated with significant risk of neurologic deficits, namely speech function, it can be done. In this chapter, we present a case of an LGG involving the Broca area.

Example case

Chief complaint: right-hand paresthesias and speech disturbances

History of present illness

A 47-year-old, right-handed man with no significant past medical history who presented with right-hand numbness and paresthesias and speech disturbances. He was running when he developed intermittent right-hand numbness, and shortly thereafter developed difficulties with getting his words out. His symptoms resolved shortly thereafter, but he was concerned because of his family history of strokes. He was evaluated in the emergency room, where a magnetic resonance imaging (MRI) scan showed a brain lesion ( Fig. 5.1 ).

Medications : Levetiracetam.
Allergies : No known drug allergies.
Past medical and surgical history : None.
Family history : No history of intracranial malignancies.
Social history : Business executive. No smoking history or alcohol.
Physical examination : Awake, alert, oriented to person, place, and time; Language: intact naming and repetition; Cranial nerves II to XII intact; No drift, moves all extremities with full strength.

	Bob S. Carter, MD, PhD, Massachusetts General Hospital, Boston, MA, United States	Clark C. Chen, MD, PhD, University of Minnesota, Minneapolis, MN, United States	Jorge Navarro-Bonnet, MD, Oncologic Neurosurgery, Medica Sur, Tlalpan, Mexico	George Samandouras, MD, Matthew A. Kirkman, MEd, National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom
Preoperative
Additional tests requested	fMRI DTI Neuropsychological assessment	fMRI DTI Medical evaluation	Neuropsychological assessment fMRI DTI EEG	fMRI DTI Perfusion MRI, MRS Dopamine PET Speech and language therapist evaluation Neurooncology multidisciplinary meeting
Surgical approach selected	Left frontal stereotactic biopsy, possible awake craniotomy with speech mapping pending pathological diagnosis	Left awake craniotomy with cortical and subcortical mapping and intraoperative MRI	Left frontal awake craniotomy with cortical and subcortical mapping and 5-ALA	Left fronto-temporo-parietal awake craniotomy with cortical and subcortical mapping
Anatomic corridor	Left frontal	Left frontal through negative mapping sites	Left frontal through negative mapping sites	Left fronto-parietal through negative mapping site
Goal of surgery	Diagnosis	Safe maximal tumor resection	Safe maximal tumor resection	Safe maximal tumor resection
Perioperative
Positioning	Left supine	Left supine with right rotation	Left lateral decubitus	Left supine with right rotation
Surgical equipment	Surgical navigation Biopsy kit	Surgical navigation IOM Brain stimulator Surgical microscope with 5-ALA Intraoperative MRI	Surgical navigation Ultrasound Brain stimulator Surgical microscope with 5-ALA	Surgical navigation Brain stimulator IOM (ECoG) Surgical microscope Ultrasonic aspirator
Medications	Antiepileptics	Steroids Antiepileptics Mannitol	Steroids Antiepileptics	Steroids
Anatomic considerations	Sylvian fissure vessels, Broca area	Sylvian fissure and veins, central sulcus, pre- and postcentral gyri, AF	Broca, Wernicke, AF, face and hand motor	Distal MCA, AF, SLF III
Complications feared with approach chosen	Hemorrhage, speech deficit	Motor and speech deficit	Motor and speech deficit	MCA stroke, AF injury (phonological paraphasias and repetition disorders), SLF III injury (articulatory disorder)
Intraoperative
Anesthesia	General	Asleep-awake-asleep	Awake	Awake-awake-awake
Skin incision	Linear	Pterional	C-shaped	Inverted U
Bone opening	Left frontal	Left frontal-temporal-parietal	Left frontal	Left frontal-parietal
Brain exposure	Left frontal	Left frontal-temporal-parietal	Left frontal	Left frontal-parietal
Method of resection	Left frontal linear incision, burr hole, dural opening, pass needle biopsy under navigation guidance into center of lesion, 2–3 core biopsies, confirm lesional by pathology	Preoperatively identify tumor and motor strip based on navigation, myocutaneous flap, C-shaped dural opening based on sphenoid wing and exposing Sylvian fissure, awake patient, ECoG to identify areas of eloquence, biopsy of negative mapping sites, maximal safe resection guided by 5-ALA and eloquence, intraoperative MRI to assess for further resection, watertight dural closure	Larger craniotomy for potential recurrence, local anesthetics including dura, cortical stimulation to find positive sites, enter cortex through negative mapping sites, extensive resection guided by cortical and subcortical mapping, avoid coagulation if necessary, resection also guided by ultrasound and 5-ALA	Scalp block, smaller craniotomy based on navigation with exposure of inferior parietal lobule and distal Sylvian fissure, map face sensory area knowing that little measurable disturbances will be elicited, small corticectomy at inferior part of primary sensory cortex, regulate suction to remove parts of tumor, switch to ultrasonic aspirator using low settings (tissue select medium or high and amplitude 40%), subcortical mapping with phonology/articulation/repetition (error acceptance rate of 40%), avoid distal MCA injury with subpial resection, skeletonize vessels if pia breached
Complication avoidance	Needle biopsy	5-ALA, cortical and subcortical mapping, intraoperative MRI	Cortical and subcortical mapping, minimize bipolar cautery	Cortical and subcortical mapping, small corticectomy in sensory region, minimize bipolar cautery
Postoperative
Admission	ICU	ICU	Floor, possible discharge	Floor
Postoperative complications feared	Speech deficit	Speech and motor deficit	Cerebral edema, neurologic deficit	MCA injury, phonological paraphasias, articulatory and repetition disorders
Follow-up testing	MRI within 4 weeks after surgery	MRI within 48 hours after surgery Physical and occupational therapy	CT immediately after surgery MRI within 48 hours after surgery	MRI within 24 hours after surgery Neuropsychological assessment within 48 hours after surgery
Follow-up visits	7–10 days after surgery	2 weeks after surgery along with radiation oncology and neurooncology Radiation and chemotherapy 4–6 weeks after surgery	10 days after surgery	7 days after surgery with neurooncology multidisciplinary clinic
Adjuvant therapies recommended
Diffuse astrocytoma (IDH mutant, retain 1p19q)	Radiation/temozolomide	GTR–observation STR–temozolomide/radiation	GTR–radiation/temozolomide STR–radiation/temozolomide	GTR–observation STR–radiation/temozolomide
Oligodendroglioma (IDH mutant, 1p19q LOH)	Radiation/PCV	GTR–observation STR–radiation/PCV	GTR–radiation, radiation/PCV, or radiation/temozolomide STR–radiation, radiation/PCV, or radiation/temozolomide	GTR–observation STR–temozolomide +/− radiation
Anaplastic astrocytoma (IDH wildtype)	GTR–radiation/temozolomide STR–radiation/temozolomide	GTR–radiation/temozolomide STR–radiation/temozolomide	GTR–radiation/temozolomide STR–radiation/temozolomide	GTR–radiation/temozolomide STR–radiation/temozolomide