Right perirolandic low-grade glioma

Introduction

Low-grade gliomas (LGGs) are characterized by the presence of mutations in the isocitrate dehydrogenase (IDH) gene, in which low-grade oligodendrogliomas also possess codeletion of chromosomes 1p and 19q, whereas astrocytomas lack this codeletion. ^, In addition to genetic makeup, the prognosis for these lesions is dependent on patient age, neurologic status, and extent of resection. Among these factors, the only modifiable risk factor is the extent of resection. The challenge is that these lesions infiltrate along white matter tracts and involve eloquent cortical and subcortical structures that can preclude extensive resection. In this chapter, we present an LGG that is in close proximity and possibly involves the precentral gyrus in the nondominant hemisphere.

Example case

Chief complaint: seizure

History of present illness

A 44-year-old, right-handed male with no significant past medical history who presented after a seizure event. He was at work and was standing, when he had an acute loss of consciousness accompanied by diffuse body shaking, and a fall in which he struck his head. He underwent imaging that revealed a brain lesion ( Fig. 3.1 ).

Medications : Levetiracetam.
Allergies : No known drug allergies.
Past medical and surgical history : None.
Family history : No history of intracranial malignancies.
Social history : Works as an accountant. No smoking history or alcohol.

Physical examination : Awake, alert, oriented to person, place, and time; Cranial nerves II to XII intact; No drift, moves all extremities with full strength.

	Miguel A. Arraez, MD, PhD, Carlos Haya University Hospital, Malaga, Spain	Juan A. Barcia, MD, PhD, Hospital Clínico San Carlos, Complutense University, Madrid, Spain	Mitchel S. Berger, MD, University of California at San Francisco, San Francisco, CA	Shawn L. Hervey-Jumper, MD, University of California at San Francisco, San Francisco, CA
Preoperative
Additional tests requested	MRS DTI fMRI	DTI fMRI Neuropsychological assessment	MEG DTI	MEG DTI Neuropsychological assessment
Surgical approach selected	Right fronto-temporal craniotomy with asleep motor mapping and intraoperative MRI	Right frontal craniotomy with cortical and subcortical mapping	Right frontal craniotomy with asleep motor mapping	Right frontal craniotomy with asleep motor mapping
Anatomic corridor	Right frontal	Right frontal	Right frontal	Right frontal
Goal of surgery	Maximal resection	Cytoreduction with functional preservation, diagnosis	Maximal resection with preservation of motor function	Maximal resection with preservation of motor function
Perioperative
Positioning	Right supine with left rotation	Right supine neutral	Right supine	Right supine
Surgical equipment	IOM Brain stimulator Surgical navigation Surgical microscope with 5-ALA Ultrasonic aspirator Intraoperative MRI	IOM Surgical navigation Brain stimulator Ultrasonic aspirator	IOM Transcranial motor stimulation Bipolar and monopolar brain stimulators Surgical microscope	IOM (EMG) Surgical navigation Brain stimulation Surgical microscope Ultrasonic aspirator
Medications	Steroids Antiepileptics	Steroids Antiepileptics	Mannitol Steroids Antiepileptics	Mannitol Steroids Antiepileptics
Anatomic considerations	Frontal and parietal sulci, primary motor cortex, CST, interhemispheric region, bridging veins	Sagittal suture, sagittal sinus and veins, central sulcus, precentral gyrus, SMA, MFG, IFG, cingulate gyrus, corpus callosum, pericallosal arteries	Sagittal sinus and draining veins, primary motor cortex, CST	SMA, premotor cortex, primary motor cortex, primary sensory cortex, callosomarginal and pericallosal arteries
Complications feared with approach chosen	Injury to superior sagittal sinus and bridging veins, motor deficit	Motor deficit, venous injury	Motor deficit, expect SMA syndrome	Motor deficit, expect SMA syndrome
Intraoperative
Anesthesia	General	Asleep-awake-asleep	General	General
Skin incision	Fronto-parieto-temporal	Pterional	Pterional	L-shaped
Bone opening	Bifrontal craniotomy eccentric to the right	Right frontal craniotomy up to sagittal sinus	Right frontal ipsilateral to sagittal sinus	Right frontal
Brain exposure	Right frontal	Right frontal (SFG, MFG), and central sulcus	Right frontal	Right frontal
Method of resection	Right frontal dural opening up to midline with preservation of bridging veins, cortical mapping to identify motor area, identify boundaries of lesion, removal of tumor along safe regions, subcortical stimulation in vicinity of CST, intraoperative MRI to guide further resection, insertion of subgaleal drain with low pressure	Right frontal craniotomy up to sagittal sinus with wide enough exposure of SFG/MFG/interhemispheric/central sulcus, awake patient, SMA and motor cortex mapping, subpial tumor resection within SFG/MFG/cingulate gyrus/corpus callosum with preservation of the motor cortex/CST by subcortical stimulation/ventricular ependymal lining	Exposure up to sagittal sinus, cortical and subcortical brain mapping with intermittent TMS, continue resection until motor cortex encountered, dural tack up suture, insertion of subgaleal drain	Cortical brain stimulation up to 16 mA to identify primary motor cortex, resect just anterior to primary motor cortex, resect along anterior and medial margins via subpial resections up to lateral margin, expose falx/cingulate sulcus/callosomarginal arteries and anterior margin of primary motor cortex, subcortical stimulation to 5 mm from CST
Complication avoidance	Large bony opening, cortical and subcortical mapping	Large bony opening, cortical and subcortical motor mapping, subpial dissection	Large bony opening, cortical and subcortical brain mapping with intermittent TMS	Cortical and subcortical stimulation, leaving posterior margin for last
Postoperative
Admission	ICU	ICU	ICU	ICU
Postoperative complications feared	Motor deficit, cognitive dysfunction	CSF leak, expected SMA syndrome	Transient SMA, motor deficit	SMA syndrome
Follow-up testing	MRI within 72 hours after surgery	CT immediately after surgery MRI within 1 month after surgery Rehabilitation if SMA syndrome	MRI with DWI and DTI within 48 hours after surgery	MRI within 48 hours after surgery
Follow-up visits	7 days after surgery	7 days after surgery 1 month after surgery	Dependent on lesion type	14 days after surgery
Adjuvant therapies recommended
Diffuse astrocytoma (IDH mutant, retain 1p19q)	STR–radiation/temozolomide GTR–radiation/temozolomide	STR–radiation/temozolomide GTR–radiation (unmethylated), radiation/temozolomide (methylated)	STR–radiation/temozolomide GTR–observation	STR–radiation/temozolomide GTR–observation
Oligodendroglioma (IDH mutant, 1p19q LOH)	STR–radiation/PCV GTR–radiation/PCV	STR–radiation/PCV GTR–radiation/PCV	STR–chemotherapy GTR–observation	STR–tumor board discussion but likely chemoradiation GTR–observation
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