Right temporal low-grade glioma

Introduction

A common location of low-grade gliomas (LGGs) is the temporal lobe, in which the number ranges from 15% to 25% in several series. Patients with temporal lobe LGGs typically present with seizures in addition to deficits in neurocognitive function, namely attention, object naming, and language. ^, Surgery for left and right temporal lobe LGGs has different risk profiles and potentially different approaches. ^, Although nondominant-hemisphere lesions are considered to have lower risk profiles than their counterpart on the dominant hemisphere, surgery can be associated with significant morbidity. ^, In this chapter, we presents a case of a right temporal lobe LGG.

Example case

Chief complaint: seizures

History of present illness

An 18-year-old, right-handed man with no significant past medical history presented with seizures. He has complained of recurrent episodes of staring spells and abnormal smells. He saw his primary care physician who ordered brain imaging, which revealed a brain tumor ( Fig. 11.1 ). He was started on levetiracetam. He was referred for further evaluation and management.

Medications : Levetiracetam.
Allergies : No known drug allergies.
Past medical and surgical history : None.
Family history : No history of intracranial malignancies.
Social history : Senior high school student. No smoking 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.

	Omar Arnaout, MD, Brigham and Women’s Hospital, Boston, MA, United States	Santiago Gil-Robles, MD, PhD, Universidad Europea de Madrid, Madrid, Spain	Manabu Natsumeda, MD, PhD, Niigata University, Niigata, Japan	Maryam Rahman, MD, University of Florida, Gainesville, FL, United States
Preoperative
Additional tests requested	None	DTI MR perfusion/MRS Neuropsychological assessment	Cerebral angiogram with Wada MRS with 2-HG analysis DTI 3D-CTA/V	DTI
Surgical approach selected	Right temporal craniotomy	Right pterional craniotomy with anterior temporal lobectomy with amygdalohippocampectomy and inferior insular resection with awake cortical and subcortical mapping	Right temporal craniotomy for temporal lobectomy with intraoperative CT	Right fronto-temporal craniotomy with intraoperative MRI
Anatomic corridor	Right temporal lobe	Right temporal lobe, opening of ventricle, amygdalohippocampectomy and inferior insular resection	Right temporal lobe	Right temporal lobe
Goal of surgery	Maximal safe resection, seizure control	Extensive resection with functional preservation	Gross total resection	Gross total resection
Perioperative
Positioning	Right supine with left head rotation	Right lateral	Right supine 70-degree head rotation	Right supine
Surgical equipment	Surgical navigation Surgical microscope	Brain stimulator Ultrasonic aspirator Surgical navigation Speech therapist/Neuropsychological assessment	Intraoperative CT/MRI Surgical navigationEctrocorticography	Intraoperative MRI Surgical navigation Surgical microscope with fluorescent filter
Medications	Steroids Antiepileptics	Steroids Antiepileptics	Steroids Mannitol Antiepileptics	Steroids Mannitol Antiepileptics Fluorescein
Anatomic considerations	Sylvian fissure and vessels, temporal stem	Anterior choroidal artery, MCA M1 perforators IFOF	Right temporal gyri and sulci, temporal horn of lateral ventricle, temporobasal vein, SMCV, vein of Labbe, amygdala, hippocampus, uncus, anterior choroidal artery choroidal point	Sylvian fissure Meyer loop
Complications feared with approach chosen	Stroke	Subpial dissection to avoid vascular injury Awake cortical and subcortical mapping	Sylvian vascular injury Visual field deficit	Sylvian vascular injury Visual field deficit
Intraoperative
Anesthesia	General	Awake-asleep-awake	General	General
Skin incision	Curvilinear	Pterional	Reverse question mark	Reverse question mark
Bone opening	Temporal	Frontal-temporal	Temporal	Frontal-temporal
Brain exposure	Temporal	Frontal-temporal	Temporal	Frontal-temporal
Method of resection	Skin opened separate from temporalis along different curve than incision, split temporalis, subperiosteal dissection to expose temporal squamosa, temporal craniotomy with single burr hole exposing STG/MTG/ITG, cruciate dural opening, lateral temporal lobe debulked with bipolar and suction, identify temporal horn and use as medial extent of resection, subpial resection up to Sylvian fissure as superior margin, temporal tip identified and folded in for resection, posterior margin confirmed by ultrasound and navigation, temporal stem identified and resected from insula respecting lenticulostriate vessels as medial border	Subfascial temporal muscle dissection, fronto-temporal craniotomy with posterior extension, intradural and muscle local anesthesia, dural opening, standard anterior temporal lobectomy with opening of ventricle, awaken patient, calibration of stimulation parameters (1.5–3 mA) based on anarthria over ventral premotor cortex, speech therapist for semantic association tasks to detect temporal stem and IFOF with stimulation, mark limits based on functional mapping, patient put to sleep, subpial resection of inferior insula and amygdalohippocampectomy, intraoperative scan to determine if additional nonfunctional tissue can be resected	Two layer skin flap, right fronto-temporal craniotomy, removal of temporal base and sphenoid ridge, determination of inferior horn and posterior aspect of tumor based on navigation, en bloc tumor resection through MTG as superior margin and posterior aspect of tumor and along base of tumor after opening inferior horn, keep temporobasal vein intact, and subpial removal of remaining tumor around inferior horn, intraoperative CT/MRI to assess resection, watertight dural closure, subgaleal drain	Myocutaneous flap, frontotemporal craniotomy maximizing exposure anteriorly and inferiorly, navigation to confirm posterior aspect of tumor and Meyer loops based on fMRI, identify Sylvian fissure, cortisectomy through superior and MTG at posterior aspect of tumor and resect everything anteriorly to this, leave arachnoid/pia intact to avoid cranial nerve III and PCA intact with microscopic visualization, avoid insula, intraoperative MRI and fluorescein to assess resection
Complication avoidance	Two-layered opening, anatomic boundaries	Subpial Awake cortical and subcortical mapping, mapping of IFOF	Subpial Intraoperative CT/MRI	Subpial Intraoperative MRI
Postoperative
Admission	ICU	ICU	ICU	ICU
Postoperative complications feared	Stroke	Anterior choroidal artery, motor deficit, visual field deficit	Visual field impairment, cognitive dysfunction	MCA injury/stroke, visual field deficit
Follow-up testing	MRI within 48 hours after surgery	MRI within 48 hours after surgery Neuropsychological assessment	CT immediately postoperative MRI within 24 hours after surgery Neuropsychological assessment 1 week after surgery	MRI within 48 hours after surgery
Follow-up visits	7–10 days after surgery	7–10 days after surgery MRI 3–4 months	2–3 weeks after surgery	2 weeks after surgery with neuro-oncology 6 weeks after surgery
Adjuvant therapies recommended
Diffuse astrocytoma (IDH mutant, retain 1p19q)	STR–radiation/temozolomide GTR–radiation/temozolomide	<4 mm/year growth rate–observation >4 mm/year growth rate–radiation/temozolomide	STR–radiation/temozolomide GTR–observation	Screened for clinical trial STR–radiation/temozolomide GTR–radiation/temozolomide
Oligodendroglioma (IDH mutant, 1p19q LOH)	STR–second look surgery or radiation/temozolomide GTR–observation	STR: <4 mm/year growth rate–observation; >4 mm/year growth rate–PCV GTR–observation	STR–radiation/PAV or temozolomide GTR–observation	Screened for clinical trial STR–radiation/temozolomide or radiation/PCV GTR–radiation/temozolomide or radiation/PCV
Anaplastic astrocytoma (IDH wild type)	STR–radiation/temozolomide GTR–radiation/temozolomide	Homogenous AA–radiation/temozolomide AA foci removal–treatment as for diffuse astrocytoma	STR–radiation/temozolomide GTR–radiation/temozolomide	Screened for clinical trial STR–radiation/temozolomide GTR–radiation/temozolomide