Right insular high-grade glioma

Introduction

The insula is a complex structure both anatomically and functionally. Functionally, the insula plays critical roles in memory, executive function, motor integration, and motor planning, among others. Although the majority of insular gliomas are low grade, a significant portion of high-grade gliomas can also involve the insula. Surgery in this region is challenging because of its complex anatomic location with several adjacent critical cortical and subcortical structures, in which morbidity rates are as high as 60%, and subtotal resections rates range from 62% to 100% in several series. In this chapter, we present a case of a nondominant insular high-grade glioma.

Example case

Chief complaint: seizures

History of present illness

A 47-year-old, right-handed woman with a history of hypertension presented with a seizure. She was working and developed generalized tonic-clonic movement with loss of consciousness. She was seen locally where an excisional biopsy was done 2 weeks prior and revealed a grade II astrocytoma, but tissue from the enhancing portion was not obtained. She is being referred for further evaluation and management ( Fig. 21.1 ).

Medications : Lisinopril, levetiracetam.
Allergies : No known drug allergies.
Past medical and surgical history : Hypertension, right temporal biopsy 2 weeks prior.
Family history : No history of intracranial malignancies.
Social history : Nurse, smokes 1 pack per day for 20 years, social 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.
Imaging: Chest/abdomen/pelvis imaging negative for primary disease.

	Mitchel S. Berger, MD, University of California at San Francisco, San Francisco, CA, United States	Jorge Navarro-Bonnet, MD, Oncologic Neurosurgery, Medica Sur, Tlalpan, Mexico	Ganesh Rao, MD, Baylor College of Medicine, Houston, TX, United States	George Samandouras, MD, Matthew A. Kirkman, MEd, National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom
Preoperative
Additional tests requested	DTI MEG	DTI Neuropsychological assessment EEG	DTI fMRI Neuropsychological assessment	DTI fMRI Perfusion MRI, MRS CT angiogram Neuropsychological assessment Neurooncology multidisciplinary meeting
Surgical approach selected	Right fronto-temporal craniotomy with awake motor mapping with 5-ALA	Right fronto-temporal awake craniotomy with awake cortical and subcortical mapping with 5-ALA	Right fronto-insular craniotomy with awake motor cortical and subcortical mapping	Right fronto-temporal craniotomy with intraoperative MRI and 5-ALA
Anatomic corridor	Right fronto-temporal with awake motor mapping	Right fronto-temporal trans-Sylvian	Right frontal and temporal opercula	Right trans-Sylvian, and frontal and temporal opercula
Goal of surgery	Gross total resection of enhancing and FLAIR components	Maximal safe resection	Maximal safe resection including FLAIR	Maximal safe resection including FLAIR
Perioperative
Positioning	Right supine with left rotation	Right lateral decubitus	Right supine with left rotation	Right supine with left rotation
Surgical equipment	Surgical navigation Surgical microscope with 5-ALA Brain stimulator	Surgical navigation Ultrasound Surgical microscope with 5-ALA Brain stimulator Ultrasonic aspirator	Surgical navigation Ultrasound Surgical microscope	Surgical navigation Surgical microscope with 5-ALA Ultrasonic aspirator Intraoperative MRI
Medications	Steroids Antiepileptics	Steroids Antiepileptics	Steroids Antiepileptics	Steroids
Anatomic considerations	Insular anatomy MCA and its branches	MCA, head of the caudate and putamen	Lenticulostriate arteries medial and deep, internal capsule, Sylvian veins, primary motor cortex	M2 and M3 segments of MCA, CST at level of superior limiting insular sulcus, globus pallidus, head of caudate
Complications feared with approach chosen	Injury to MCA branches or lenticulostriate branches, as well as CST	MCA stroke, injury to internal capsule and basal ganglia	MCA and Sylvian vein injury, retraction on frontal and temporal lobes	M2 or M3 injury, motor deficit, injury to lateral lenticulostriate arteries, facial weakness
Intraoperative
Anesthesia	Asleep-awake-asleep	Awake	Asleep-awake-asleep	General
Skin incision	Pterional	Dandy incision	Pterional	Pterional
Bone opening	Right fronto-temporal	Right fronto-temporal	Right fronto-temporal	Right fronto-temporal
Brain exposure	Right fronto-temporal	Right fronto-temporal	Right fronto-temporal	Right fronto-temporal
Method of resection	Local anesthetic in scalp, craniotomy, awaken patient, cortical mapping of frontal operculum and posteriorly until identification of face motor cortex, corticectomy based on negative mapping sites, resection of STG and frontal operculum, resection of insular component with subcortical mapping and navigation, tack up sutures, insertion of subgaleal drain	Keep patient awake from beginning to monitor for patient comfort, infiltrate skin with local anesthetic, right fronto-temporal craniotomy anterior to projection of Sylvian fissure with one-half frontal and one-half temporal, anesthetize dura, open dura monitoring for MCA vessels, Sylvian fissure opening, mapping of adjacent cortex, entry based on negative mapping areas, avoid coagulation unless necessary, safe maximal resection between vascular branches that are silent based on mapping and navigation, resection aided by navigation, ultrasound, and 5-ALA, stop resection at internal capsule	LMA placement and regional scalp block, myocutaneous flap, right fronto-temporal craniotomy, large dural opening, ultrasound to identify hyperechoic areas, awaken patient and perform motor function testing, resection of frontal and temporal opercula based on negative motor mapping, open pia of insula, periodic motor mapping, resection until all of hyperechoic area removed, place patient back under anesthesia for closure	Right fronto-temporal craniotomy, dural openings, split Sylvian fissure, visualize/understand MCA anatomy, including lateral lenticulostriate arteries, open two cortical windows in the frontal and temporal opercula, join surgical cavities behind the M2 and M3 branches, obtain intraoperative MRI to confirm resection/avoid CST damage at level of superior limiting insular sulcus and globus pallidus if not infiltrated by tumor, use 5-ALA to help target enhancing components, debulk tumor with ultrasonic aspirator on low settings (tissue select medium or high and 40% amplitude), avoid bipolar cautery if possible
Complication avoidance	Cortical and subcortical mapping	Cortical and subcortical mapping, minimal bipolar cautery, stop resection at internal capsule	Resection of frontal and temporal opercula based on motor mapping, continuous motor mapping through resection	Sylvian fissure split to understand MCA anatomy, transopercular to resect insular lesion, intraoperative MRI to guide extent of resection and avoidance of critical areas, avoid bipolar coagulation
Postoperative
Admission	ICU	Floor	ICU	Floor
Postoperative complications feared	MCA and lenticulostriate ischemia, motor deficit	MCA and Sylvian vessel ischemia, injury to internal capsule and basal ganglia	Vascular injury, damage to descending white matter tracts, motor deficit	Motor deficit, vascular injury to M2 or M3 segments as well as lenticulostriate vessels
Follow-up testing	MRI within 24 hours after surgery Full molecular panel	CT immediately after surgery MRI within 48 hours after surgery	MRI within 24 hours after surgery	MRI within 24 hours after surgery
Follow-up visits	10 days after surgery with neurooncology	10 days after surgery	7–10 days after surgery 1 month after surgery with MRI	7 days after surgery with neurooncology multidisciplinary clinic
Adjuvant therapies recommended
IDH status	Mutant–radiation/temozolomide +/– lomustine Wild type–radiation/temozolomide +/– lomustine	Mutant–temozolomide Wild type–radiation/temozolomide	Mutant–temozolomide Wild type–radiation/temozolomide	Mutant–radiation/temozolomide Wild type–radiation/temozolomide
MGMT status	Methylated–radiation/temozolomide Unmethylated–radiation/temozolomide under 65 and radiation only over 65 years of age	Methylated–temozolomide Unmethylated–radiation/temozolomide	Methylated–temozolomide Unmethylated–radiation/temozolomide	Methylated–radiation/temozolomide Unmethylated–radiation/temozolomide