1 BOLD fMRI for Language Mapping Jay J. Pillai, M.D. Director of Functional MRI Associate Professor Neuroradiology Division The Russell H. Morgan Department.

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BOLD fMRI for Language Mapping Jay J. Pillai, M.D.Director of Functional MRI

Associate ProfessorNeuroradiology Division

The Russell H. Morgan Department ofRadiology and Radiological Science

Johns Hopkins Univ. School of Medicine

Utility of BOLD Imaging for presurgical mapping

• Preoperative risk assessment– Language lateralization– Eloquent cortical localization

• Determine safest surgical trajectory• Guide complementary intraoperative cortical mapping (ICS)• Promote paradigm shift from positive to negative ICS

mapping– Smaller craniotomy, shorter mapping times & reduced morbidity

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Giussani, Carlo; Roux, Frank-Emmanuel; MD, PhD; Ojemann, Jeffrey; Sganzerla, Erik; Pirillo, David; Papagno, CostanzaIs Preoperative Functional Magnetic Resonance Imaging Reliable for Language Areas Mapping in Brain Tumor Surgery? Review of Language Functional Magnetic

Resonance ImagingNeurosurgery. 66(1):113-120, January 2010.

BOLD validation:

Studies comparing

preop language

fMRI to ICS (Localiz)—Giussani et

al., Neurosurgery

Jan 2010

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Validation of fMRI: studies comparing fMRI to Wada [and in some cases ICS] results—Lang Lat & Localiz:

Study comparing fMRI to ICS+/-Wada, 1996-2004

fMRI task (Lang/ motor)

Concordance with Wada

Concordance with ICS

Binder JR et al. 1996; Neurology 46(4): 978-984

L 22/22 lateraliz (100%) ( r=0.96 for LI)

NA

Bahn M et al., AJR 1997. 169(2):575-9.

-- 7/7 (100%) NA

Hertz-Pannier L et al. Neurology 1997. 48(4):1003-1012.

L 6/6 (100%) 1/1 (100%)

Benson RR et al., Neurology 1999. 52(4):798-809.

L 12/12 (100%) 10/11 (91%)

Hirsch J, et al.. Neurosurgery 2000. 47(3): 711-721.

L, M 13/13 (100%) 30/30 (100%)

Sabbah P et al. Neuroimage 2003; 18(2):460-7

L 19/20 (95%) NA

Woermann FG et al. Neurology 2003; 61(5): 699-701.

-- 91/100 domin (91%) NA

Meneses MS et al. Arquivos de Neuro-Psiquiatria 2004; 62(1):61-7.

L 5/5 (100%) NA

FROM: Pillai JJ, Language fMRI IN Holodny AI (Ed), Functional Neuroimaging: A Clinical Approach, 2008,

Informa Healthcare (New York, NY)

Complementary role of ICS and BOLD fMRI---Why occasional discordance?

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1) BOLD—positive activation, essential vs. participatory (mult tasks), NVU

2) ICS—negative activation3) Covert vs. Overt tasks4) Lack of standardization (OR ---neuropsych/lang---& BOLD)5) Brain shift

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Language Representation in the Brain: Classical Brodmann’s areas

From Waxman SG. Correlative Neuroanatomy, 24th Ed. Lange Medical Books/McGraw-Hill, New York, 2000.

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Lubrano V, Draper L, Roux FE.What makes surgical tumor resection feasible in Broca's area? Insights into intraoperative brain mapping. Neurosurgery. 2010 May;66(5):868-75; discussion 875.

Study of 16 patients, with 29 language sites identified by positive stimulation, only 14 in classic Broca’s area

Localization varied by pathology: those w cavernomas or well-circumscribed tumors had 100% of sites within BA

Patients with gliomas—only 25% of sites corresponded to classical BA

Lubrano et al.,

May 2010 issue of

Neurosurgery

Landmark ICS study —value of ICS/negative mapping

(Sanai et al., 2008 NEJM)

• 145 of 250 patients (58.0%) with at least one site with intraop stimulation-induced speech arrest, 82 patients w anomia, and 23 patients w alexia.

• Overall, 3094 of 3281 cortical sites (94.3%) were not associated with

stimulation-induced language deficits. • 6 months after surgery, only 1.6% incidence of persistent language

deficit.

• Surprising variability in language localization/ICS reduces postop morbidity

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Fiber tracking results.

Saur D et al. PNAS 2008;105:18035-18040

©2008 by National Academy of Sciences

Glasser MF, Rilling JK. DTI Tractography of the Human Brain's Language Pathways. Cerebral Cortex

2008; 18(11):2471-2482

• Performed a BOLD meta-analysis & overlaid activations onto results of group DTT(n=20)—STG & MTG seeding: – phonemic, lexical/semantic & prosodic processing.

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New Dual Stream Model of Language---validated by BOLD/DTT by Saur et al., 2008

Dorsal Stream--sensorimotor mapping of sound to articulation/sublexical repetition of speech STG to premotor cortices via the AF/SLF

Ventral Stream---linguistic processing of sound to meaning/language comprehension MTG to ventrolateral PFC via the extreme capsule

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ISM validation of DTT/dual stream--Leclercq (2010)

• 10 patients with low-grade gliomas or dysplasia in language areas.

• Compared DTT w intraop sc stim mapping (ISM)

• 17 (81%) of 21 positive stimulations concordant with DTT fiber bundles (within 6 mm)

• Stimulations of the AF ---articulatory and phonemic/syntactic dysfunction--DS

• Stimulations of the IFOF ---semantic paraphasias--VS

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Leclercq D, Duffau H, Delmaire C, Capelle L, Gatignol P, Ducros M, Chiras J, Lehéricy S. Comparison of diffusion tensor imaging tractography of language tracts and intraoperative subcortical stimulations..J Neurosurg. 2010 Mar;112(3):503-11.

However, Some Limitations of BOLD

• Neurovascular Uncoupling• Patient Task performance issues--training, monitoring,

variable capabilities related to deficits• Essential vs. Participatory (nonessential) function—role of

convergent activation & complementary ICS• Interpretation relies heavily on statistical thresholding• Need for multiple tasks to assess entire language network

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How do we address these limitations?• 1) Do detailed QC analysis

• 2) MRPor CVR mapping to eval risk of NVU

• 3) Use multiple tasks and assess convergence of activation (esp important in language—exp vs rec)

• 4) Use higher thresholds for motor and visual, but lower ones for language mapping

• 5) Rely on language tasks that are the best for lateralization

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Neurovascular uncoupling--CVR maps & Perfusion MR

• BOLD CVR maps during breath-hold task or external CO2 challenge

• MR perfusion (T2* DSC) can evaluate rCBV & rCBF elevations related to tumor angiogenesis

• Both approaches can evaluate risk for FN activ due to NVU

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