High-resolution cortical parcellation based on conserved brain landmarks for localization of multimodal data to the nearest centimeter

Precise cortical brain localization presents an important challenge in the literature. Brain atlases provide data-guided parcellation based on functional and structural brain metrics, and each atlas has its own unique benefits for localization. We offer a parcellation guided by intracranial electroencephalography, a technique which has historically provided pioneering advances in our understanding of brain structure-function relationships. We used a consensus boundary mapping approach combining anatomical designations in Duvernoy's Atlas of the Human Brain, a widely recognized textbook of human brain anatomy, with the anatomy of the MNI152 template and the magnetic resonance imaging scans of an epilepsy surgery cohort. The Yale Brain Atlas consists of 690 one-square centimeter parcels based around conserved anatomical features and each with a unique identifier to communicate anatomically unambiguous localization. We report on the methodology we used to create the Atlas along with the findings of a neuroimaging study assessing the accuracy and clinical usefulness of cortical localization using the Atlas. We also share our vision for the Atlas as a tool in the clinical and research neurosciences, where it may facilitate precise localization of data on the cortex, accurate description of anatomical locations, and modern data science approaches using standardized brain regions.

Craniotomy Size for Subdural Grid Electrode Placement in Invasive Epilepsy Diagnostics

BACKGROUND

Traditionally, for subdural grid electrode placement, large craniotomies have been applied for optimal electrode placement. Nowadays, microneurosurgeons prefer patient-tailored minimally invasive approaches. Absolute figures on craniotomy size have never been reported. To elucidate the craniotomy size necessary for successful diagnostics, we reviewed our single-center experience.

METHODS

Within 3 years, 58 patients with focal epilepsies underwent subdural grid implantation using patient-tailored navigation-based craniotomies. Craniotomy sizes were measured retrospectively. The number of electrodes and the feasibility of the resection were evaluated. Sixteen historical patients served as controls.

RESULTS

In all 58 patients, subdural electrodes were implanted as planned through tailored craniotomies. The mean craniotomy size was 28 ± 15 cm2 via which 55 ± 16 electrodes were implanted. In temporal lobe diagnostics, even smaller craniotomies were applied (21 ± 11 cm2). Craniotomies were significantly smaller than in historical controls (65 ± 23 cm2, p < 0.05), while the mean number of electrodes was comparable. The mean operation time was shorter and complications were reduced in tailored craniotomies.

CONCLUSION

Craniotomy size for subdural electrode implantation is controversial. Some surgeons favor large craniotomies, while others strive for minimally invasive approaches. For the first time, we measured the actual craniotomy size for subdural grid electrode implantation. All procedures were straightforward. We therefore advocate for patient-tailored minimally invasive approaches - standard in modern microneurosurgery - in epilepsy surgery as well.

Music and Mind: In Memoriam Professor Carlo Alberto Pagni, MD, PhD: February 13, 1931 -March 1, 2009

Carlo Alberto Pagni, born in La Spezia, Italy, on February 13, 1931, was an eminent and respected professor of neurosurgery and chairman of the neurosurgical clinic of the University of Turin from 1980 to 2003. He died on March 1, 2009. As a professor of neurology and neurological surgery he was renowned as an expert on vascular, tumor, and functional neurosurgery. Beyond the Italian Neurosurgical Society, he was the doyen of functional neurosurgery, specializing in motor cortex stimulation for the treatment of focal dystonia, Parkinson's disease, and postictal spasticity and pain. His home was his castle, and his family was fundamental to his life. He shared with his wife, Sandra, his passion for piano playing and for their remarkable library, and together with friends, he and his wife enjoyed dinners with fine food and Barolo wines. Listening to this Grand Seigneur talking about and explaining the music of, above all, Ludwig van Beethoven, and Richard Wagner, one felt he was emotionally just "music and mind". You can imagine this from his books on music, chess, and neuroscience. Indeed, he adored playing correspondence chess worldwide. A sportsman too, he loved hiking, mountaineering, skiing, swimming, and fishing. Nature was his source for slowing down, for regenerating, and for collecting his strength for new projects and new challenges. Friends will remember Dr. Pagni as a Grand Seigneur.