hongmin bai, weimin wang, et al. guangzhou liuhuaqiao hospital intraoperative functional mapping...

Hongmin Bai, Weimin Wang, et al.

Guangzhou Liuhuaqiao hospital

Intraoperative Functional Mapping

Using

Direct Electrical Stimulations

广州军区广州总医院

Bartholow R (1874) Experimental investigations into functions of the human brain. Am J Med Sci 67: 305-313

Foerster O(1931) The cerebral cortex of man. Lancet 2: 309-312

Roberts Bartholow

(1874)

Otfrid Otfrid FoersterFoerster

(1931)(1931)


Wilder Penfield

Homunculus(1937)Homunculus(1937) Penfield W, Bolchey E (1937) Somatic motor

and sensory representation in the cerebral cortex of man as studied by electrical stimulation. Brain 60: 389-443


George OjemannOjemann cortical stimulation


Michael Berger

Michael Taylor

Hugues Duffau


Wang Weimin(2002)

Jiang Tao(2004)


Why should we introduce DES into neurosurgery?

15-27.5% risk of permanent post-operative 15-27.5% risk of permanent post-operative neurological deficit without functional mappingneurological deficit without functional mapping

Interindividual physiological anatoma-functional Interindividual physiological anatoma-functional variabilityvariability

Mechelli A etal. Effective connectivity and intersubject variability: using a multisubject network to test differences and commonalities. NeuroImage, 2002; 17: 1459-69

Brell M. factors influencing surgical complication of intra-axial brain tumours. Acta Neurochir(Wien), 2000; 142: 739-750


Why should we introduce DES into neurosurgery?

Neurofunctional imaging limitationNeurofunctional imaging limitation75% of sensitivity and 80% of specificity

using PET scan and 81% of sensitivity and 53% of specificity using fMRI

Incapable of differentiate essential areas and potentially removal areas

Incapable of mapping the white matterUn-real-time

Roux FE, etal. Language function magnetic resonance imaging in preoperative assessment of language areas: correlation with direct cortical stimulation. Neurosurgery. 2003; 52: 1335-47


Principles of stimulation

Neuron membrane rest Neuron membrane rest potential: -60—-100mVpotential: -60—-100mV

Negative inside, positive Negative inside, positive outsideoutside

Cathode depolarization, Cathode depolarization, anode hyper-anode hyper-

Once reach Threshold, Once reach Threshold, influx of Nainflux of Na++

All or nothingAll or nothing


Stimulation parameters

Rectangular pulses, biphasic currentRectangular pulses, biphasic current Sinusoidal impulse induce “accommodation”, so the Sinusoidal impulse induce “accommodation”, so the

threshold is elevated. threshold is elevated. Monophase=monopolar: false positive; avoid overlapping Monophase=monopolar: false positive; avoid overlapping

which induce excessive heat by hydrolysiswhich induce excessive heat by hydrolysis

Frequencies from 50Hz to 60 HzFrequencies from 50Hz to 60 Hz refractory and hyper-excitability period of neuronal Mrefractory and hyper-excitability period of neuronal M


Stimulation parameters

DurationDuration Pulse duration: 1ms; stimulation duration: 1s(sensori-Pulse duration: 1ms; stimulation duration: 1s(sensori-

motor), 4s(cognitive function)motor), 4s(cognitive function)

IntensityIntensity Never exceed after-discharge by EEG except in Never exceed after-discharge by EEG except in

children due to non-myelinizationchildren due to non-myelinization from 1-8mA(local anesthesia)from 1-8mA(local anesthesia) From 4-18mA(general anesthesia)From 4-18mA(general anesthesia) 0.5-2mA for brain stem and spinal 0.5-2mA for brain stem and spinal Progressive increase by 1mAProgressive increase by 1mA


Practical stimulation methods

Stimulate the whole of expose cortical area, every Stimulate the whole of expose cortical area, every 5mm5mm22

Stimulate every site at least 3 timesStimulate every site at least 3 times Never stimulate the same cortical area twice Never stimulate the same cortical area twice

consecutivelyconsecutively Always monitor the function after stimulationAlways monitor the function after stimulation Keep the stimulation site dry, without serum, CSF Keep the stimulation site dry, without serum, CSF

or bloodor blood Irrigate the cortex with cold saline or serum if a Irrigate the cortex with cold saline or serum if a

seizure occurs during stimulationseizure occurs during stimulation


Environment

Awake anesthesia(propofol+analgesia)Awake anesthesia(propofol+analgesia) Intra-operative tasksIntra-operative tasks

Selected according with the lesional siteSelected according with the lesional sitePre-operative neuropsychological assessmentPre-operative neuropsychological assessment

Monitoring by both machine(by EMG) and Monitoring by both machine(by EMG) and specialty observer(contra-lateral upper specialty observer(contra-lateral upper and lower limbs and face)and lower limbs and face)

Neuro-psychologist if mapping of cognitive Neuro-psychologist if mapping of cognitive functionfunction


Outcome of stimulation

predominant excitatory effectpredominant excitatory effect for sensori-motor for sensori-motor stimulationstimulation Observe the movement and impulsive sensoryObserve the movement and impulsive sensory Record motor invoked potential by EMGRecord motor invoked potential by EMG

predominant inhibitory effectpredominant inhibitory effect for cognitive for cognitive stimulationstimulation Counting and object naming task with “this is”Counting and object naming task with “this is” slow down, dysarthria, anarthria, anomia, speech slow down, dysarthria, anarthria, anomia, speech

arrestarrest


Virtues of DES

ReliableReliable Low sham-positive and negative stimulation with Low sham-positive and negative stimulation with

proper method describe aboveproper method describe above

SafeSafe No harm for brain No harm for brain histological examination of

resected structures first stimulated in vivo (lack of inflammation or other injury

PrecisePrecise 5mm5mm22

Real-timeReal-time

Ojemann GA(1983). Brain organization for language from the perspective of electrical stimulation mapping. Beh Brain Sci 6: 189-230


Indications

Tumor surgeryTumor surgeryAVM or CM surgeryAVM or CM surgeryEpilepsy surgeryEpilepsy surgery

maximize quality of resection,

while minimizing the risk of permanent post-operative neurological deficit


Problems

Inducing epilepsyInducing epilepsy5-20%5-20%PreventionPrevention

intensity is monitored by after-dischargeintensity is monitored by after-dischargeFrequency selection to avoid the hyper-excitabilityFrequency selection to avoid the hyper-excitabilityNever stimulate twice consecutivelyNever stimulate twice consecutivelyStimulation duration last no more than 1s or 4s in Stimulation duration last no more than 1s or 4s in

each siteeach siteTreatment: Irrigate the cortex with cold saline Treatment: Irrigate the cortex with cold saline

or serumor serum


Problems

Transitory immediate neurological worseningPost-surgical edema;IschemiaSupplementary motor area (SMA)

syndromeSMA properPre-SMA


Problems

False stimulation resultsFalse stimulation results

False positive: high intensityFalse positive: high intensity

False negative: small exposure and non-False negative: small exposure and non-

cooperation of the patient due to tiredcooperation of the patient due to tired


Tips

Keep warm during awake procedureKeep warm during awake procedure Non-injection of Luminal and other sedative Non-injection of Luminal and other sedative

hypnotics pre-surgeryhypnotics pre-surgery Never use long acting muscle relaxant Never use long acting muscle relaxant Well communication with patientWell communication with patient Existence of rapid plasiticityExistence of rapid plasiticity Early rehabilitation for transitory neurological Early rehabilitation for transitory neurological

deficitdeficit


Our experience in glioma surgery(2003-2005)

44 cases44 casesPre-operative clinical findingsPre-operative clinical findings

Epilepsy: 28/44Epilepsy: 28/44Mild neurological deficit: 17/44Mild neurological deficit: 17/44Elevated ICP: 5/44Elevated ICP: 5/44

Pathological findingPathological findingLow-grade gliomas: 28/44Low-grade gliomas: 28/44High-grade gliomas: 11/44High-grade gliomas: 11/44



Mapping resultMapping resultMotor areas were discovered in 39 patientsMotor areas were discovered in 39 patientsLanguage areas were discovered in 14 Language areas were discovered in 14

patientspatientsExtent of resectionExtent of resection

By ultrasonic: total resection in 28/37By ultrasonic: total resection in 28/37By MR: TR in 28/44; STR in 12/44; PR in 5/44By MR: TR in 28/44; STR in 12/44; PR in 5/44



Follow upFollow up Follow up is up to May 1Follow up is up to May 1stst, 2006, 2006 Non-progression survival: 35/44Non-progression survival: 35/44 Death: 6/44Death: 6/44

5 patients with GBM and one patient with anaplastic 5 patients with GBM and one patient with anaplastic astrocytomaastrocytoma

Deterioration: 3/44Deterioration: 3/44 Transitory hemi-paralysis in 15 patients and language Transitory hemi-paralysis in 15 patients and language

disorder in 11 patientsdisorder in 11 patients No operation related death and intolerable complaint No operation related death and intolerable complaint

of pain during stimulation procedureof pain during stimulation procedure

hongmin bai, weimin wang, et al. guangzhou liuhuaqiao hospital intraoperative functional mapping...

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