Papademetras

1. Papademetras • Image-guided Navigation Systems • Structural and Functional images registered to patient space • Research workstation is interfaced to commercial surgical workstation for Epilepsy surgery • Allows stable, reliable system for clinical surgery • VVLink now part of BrainLab system • Includes ability to track surgical tools • MODELS OF TUMOR GROWTH ARE CLOSEST

2. Papademetras • Brain Deformation is compensated for by stereo cameras and modeling • In cases where surgical resection is not possible, neurostimulators are used (in functionally sensitive areas) • How does one leverage prior information from normal controls • How do we emphasize robustness over accuracy?

3. CoulonCortical localization and inter-subject surface matching • For morphometric or functional studies of populations • Volume-based and sphere transformations have been used in the past • Cortical organization based on “sulcal roots” is an alternative model • Sulcal landmarks are (semi-automatically?) defined for tranform to standard space • Application can be for parcellation of brain anatomy and • QUESTIONS: How does one deal with anatomical variability. • Can this generalized to maps of brain function (e.g. language defined in surgical stimulation studies • Should multiple atlases be developed? • See: brainvisa.info

4. ClatzModeling brain tumors for patient-specific therapy • Tumor growth and mass effects are simulated through computer (linear elastic) models • Goal is to use models for patient-specific treatments

5. LeiphartNeurosurgery for brain implants • Technology for seizure detection Paradigm shift from exec (localized) center to [network] of anatomically distinct centers Synchrony precedes 70% of seizures Advanced algorithms and computation needed to predict seizures (shift from electrocorticog)

6. Reisenhuber • How does object (face) recognition work? • Is there an “Alice Cooper neuron” in the brain? • Question: How nonlinear is the fMRI/EEG brain? Is there a functional role for oscillations…?

7. Brette • Electrode introduces bias in single neuron recording • Active electrode Compensation is a computer model to remove this bias. • Message: Model based approaches can extend possibilities of standard electrode recording, for example measuring excitatory and inhibitory synaptic conductance.

8. Schmueli • Physiological noise (nuisance variables) can be removed from fMRI • Heart rate • Magnetic susceptibility corrections also shown

9. Marrelec • How do we infer interactions in fMRI • Motor network is well understood • Information exchange between brain units – definition of functional interactions • Can this be defined mathematically • Can causality be inferred from fMRI?

10. Pessiglionefunctional imaging/pharm challenges • DA involved in reward,validated in monkeys, mimicked by engineered models • Behavioral experiment in choice experiment rewarded by money (or punished by loss) • L-dopa associated with faster learning than Haldol • Model/theory ventral striatum associated with critic. Anterior putamen • Are [decisions] subconscious? • Can brain reading predict decisions?

11. GaillardEpilepsy, functional imaging and language • Auditory Description Decision Task (ADDT) fMRI • Stroke or epilepsy result in relocation of language function in R hemisphere • Exploratory data analysis (no a priori hypothesis) was done in epilepsy pts. • Posterior margin of Wernicke’s is utilized • Anterior only group vs. anterior and posterior moves to contralateral side

12. NadjaCNMC Neuroradiology ResearchNational Children’s Center, Wash DC • MRI scanners, technologies and neuroradiologists available for collab. • Areas of ongoing research • Craniofacial phenomics, head shape modeling • Molecular imaging of pediatric brain tumors • Superparamagnetic nanoparticles for MRI and optical fluorescence imaging • Tumor volumetry • Infant MRS and DTI • Fetal MRI and 3D U/S • ASL/Susceptibility weighted imaging in stroke (sickle cell) • Small animal imaging

13. Michael Levene • Multiphoton microscopy • Single molecule sensitivity • Sub micron resolution • Two photon excitation, unlike single, has a single focal point of excitation • Near IR light scatters less than blue light • Intrinsic fluorescence of UV is possible too • Hypometabolism measured in epilepsy with neurosurgeon • NADH is fluorescent, NAD is not • Long lens might be used to penetrate 3.5 mm of tissue for optical biopsy • What are clinical applications for MPM and optical imgs?

14. Olivier DavidEEG/fMRI/Epilepsy • Small animal up to 7T • Human 3T scanner • fMRI studies of unilateral epilepsy • Rat model (genetic absence • fMRI of visual stimulation (thalamic relay) • Implanted epileptic patients are used in studies of 1 Hz neurostimulation of hippocampus • Antiepileptics studied in animal (rat) models • Microelectronics developed for neural implants and adaptive control of epilepsy • Stimulation of network may be alternative model for TX • Experimental work needed prior to clinical trials • Animal studies are vital

15. Christian HabeckMultivariate neuroimage analysis • Univariate stats (SPM) are straightforward parametric and use stringent type-I error correction • Multivariate – non-parametric, better suited for distributed analysis • data dredging? • Covariance analysis of ASL MRI in Alzheimer’s appears to discriminate • Multivariate techniques could be used in meta-analyses • Where does Multivariate analysis show new insight over univariate analysis? • Epiphenomena or does Multivariate analysis really provide insights

16. ThirionGroup Analysis of fMRI • Problems with standard inference • Small samples • Spatial normalization –precision about 1cm • Critical questions • Which structures should be studied? • How to detect false positives • Which structures are cross-correlated? • Question: Build an anatomo-functional atlas (integrated and fully Bayesian) • Brainvisa software available soon.

17. BailletTime resolved imaging MEG/EEG • Atlas of basal ganglia might be used for DBS targeting – plug in for Papademetras? • Inverse problem – go from signal to map of brain (function, anatomy) • What can time perspective bring you for understanding brain function? • 400 ms duration map of tennis ball catch • Similarly conscious perception moves from visual to ventral processing of information • Optical flow (borrowed from weather models) can be used to understand dynamics of brain activity • State 1 flows to state 2 • Challenges: Reduce theory/computational gap • Make tools clinically useful tools • Richard Leahy USC collaborator