Wernicke area low-grade glioma

Introduction

Lesions in close proximity to essential cortical language functions, namely the Broca and Wernicke areas, have long been considered to not be amenable to surgical resection. Unlike in strokes, the brain can undergo reshaping of the language networks and allow for resection to occur, especially in chronic conditions, such as low-grade gliomas (LGGs). ^, Moreover, surface anatomy is not always reliable in identifying these areas intraoperatively. ^, Surgical resection can occur in these regions with minimal morbidity, as long as the surrounding eloquent cortical and subcortical structures can readily be identified and avoided. In this chapter, we present a case of an LGG in close proximity to the Wernicke area.

Example case

Chief complaint: seizures

History of present illness

A 47-year-old, right-handed man with hypertension and hyperlipidemia who presented with seizures. He was in his usual state of health until he developed intermittent episodes of right facial drooping and tingling, right-hand weakness, and inability to get any words out. These episodes have happened three to four times in the past month. He was evaluated in the emergency room where a magnetic resonance imaging (MRI) scan showed a brain lesion, and was referred for care ( Fig. 6.1 ).

Medications : Levetiracetam.
Allergies : No known drug allergies.
Past medical and surgical history : Hypertension, hyperlipidemia.
Family history : No history of intracranial malignancies.
Social history : Accountant. Occasional smoking (smokes socially) and occasional 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.

	Mark Bernstein, MD, University of Toronto, Toronto, Canada	Henry Brem, MD, Johns Hopkins University, Baltimore, MD, United States	Guilherme C. Ribas, MD, PhD, Hospital Israelita Albert Einstein, São Paulo, Brazil	Michael E. Sughrue, MD, Prince of Wales Hospital, Sydney, Australia
Preoperative
Additional tests requested	fMRI Neuropsychological assessment	fMRI MRA	fMRI DTI Language evaluation	fMRI with connectome analysis DTI
Surgical approach selected	Left fronto-temporal awake craniotomy (as opposed to wait-and-see approach based on the MEAN score)	Left fronto-temporal craniotomy with intraoperative MRI	Left awake craniotomy with cortical and subcortical mapping	Left keyhole temporo-parietal craniotomy with awake cortical and subcortical mapping
Anatomic corridor	Left frontal	Left fronto-temporal	Left subcentral gyrus	Left posterior temporal
Goal of surgery	Maximal safe resection	Maximal safe resection with preservation of neurologic function	Maximal safe resection without permanent deficit	Gross total resection
Perioperative
Positioning	Left supine with right rotation	Left supine with 60-degree right rotation	Left lateral	Left lateral
Surgical equipment	Surgical navigation Brain mapping Surgical microscope Ultrasonic aspirator	Surgical navigation IOM (SSEP/MEP) Ultrasound Surgical microscope Ultrasonic aspirator Intraoperative MRI	Surgical navigation Ultrasound Brain stimulator Ultrasonic aspirator	Surgical navigation Brain stimulator Surgical microscope
Medications	Steroids Antiepileptics	Mannitol Steroids Antiepileptic	Antiepileptics	Mannitol Steroids Antiepileptic
Anatomic considerations	Speech cortex	Sylvian fissure, MCA, vein of Labbé, superior temporal gyrus	Sylvian fissure, fronto-opercular convolutions and sulci	Opercular MCA branches, CST AF/SLF
Complications feared with approach chosen	Speech dysfunction	Speech dysfunction, motor deficit, visual field deficit	Speech dysfunction	Speech dysfunction, motor deficit
Intraoperative
Anesthesia	Awake	General	Asleep-awake-asleep	Asleep-awake-asleep
Skin incision	Linear	Linear	Question mark	Linear
Bone opening	Left frontal	Left fronto-temporal	Left fronto-temporal	Left keyhole temporo-parietal
Brain exposure	Left frontal	Left fronto-temporal	Left fronto-temporal	Left supramarginal gyrus
Method of resection	Regional field block with local anesthetic, bone flap to encompass lesion, cruciate dural opening, motor and speech mapping with brain stimulator, bring in operative microscope, find tumor pseudoplane, exploit pseudoplane as much as possible, keep resection 1 cm away from positive mapping sites, periodic confirmation with navigation	Left fronto-temporal craniotomy with bone soaked in betadine during operation, dural opening, surgical navigation to identify point where tumor comes closest to the surface, biopsy for frozen section (if high-grade glioma then carmustine wafers), internal debulking to normal white matter borders, watertight dural closure, reapproximate skull and scalp, intraoperative MRI for potential additional resection, watertight dural closure with fibrin glue, subgaleal drain	Wide left fronto-temporal craniotomy with drilling of sphenoid wing, large dural opening, expose frontal and temporal operculi, anatomic identification of exposed sulci and gyri with aid of surgical navigation and ultrasound, awaken patient, language mapping, open Sylvian fissure to expose basal aspect of tumor which projects toward subcentral gyrus, dissection anterior/superior/posterior margins while patient awake, remove with aid of ultrasonic aspirator from outer aspect toward center, resect based on anatomic boundaries	Craniotomy and dural opening adjacent to Sylvian fissure at inferior aspect, map cortex for motor/speech arrest/anomia, subpial dissection with microscope visualization inferiorly to locate fissure, identify insula based on periinsular sulci, superior cut of tumor in cortical and subcortical regions, subpial resection anterior and posterior sulcal boundaries, amputate tumor at its base based on continuous awake cortical and subcortical motor and language mapping
Complication avoidance	Awake cortical motor and speech mapping, staying away from positive sites	Closest point to cortical surface, intraoperative MRI	Wide bony opening, anatomic landmarks, awake language mapping, anatomic boundary-based resection	Awake cortical and subcortical mapping with motor and speech mapping, subpial dissection
Postoperative
Admission	Outpatient	ICU	ICU	ICU
Postoperative complications feared	Language dysfunction	Language dysfunction, visual field deficit, headaches, lethargy	Language dysfunction	MCA artery injury or vasospasm Motor deficit Language deficit
Follow-up testing	CT or MRI same day of surgery prior to discharge	MRI within 24 hours after surgery	MRI within 48 hours after surgery Language evaluation after surgery	MRI within 24 hours after surgery
Follow-up visits	10–14 days after surgery	14 days after surgery 3 months and then every 6 months after surgery	2–3 months after surgery	14 days after surgery
Adjuvant therapies recommended
Diffuse astrocytoma (IDH mutant, retain 1p19q)	STR–observation or radiation GTR–observation or radiation	STR–radiation/temozolomide GTR–observation	STR–radiation/temozolomide GTR–radiation/temozolomide	STR–observation GTR–observation
Oligodendroglioma (IDH mutant, 1p19q LOH)	STR–temozolomide +/– radiation GTR–observation	STR–temozolomide or PCV +/– radiation GTR–observation	STR–temozolomide GTR–observation	STR–patient selection GTR–patient selection
Anaplastic astrocytoma (IDH wildtype)	STR–radiation/ temozolomide GTR–radiation/ temozolomide	STR–radiation/temozolomide GTR–radiation/temozolomide	STR–radiation/temozolomide GTR–radiation/temozolomide	STR–radiation/temozolomide GTR–radiation/temozolomide