CNS 2016 Blog
When neurosurgeons remove a tumor from the brain, there is often a risk to the patient of cognitive deficits resulting from injury to the surrounding brain tissue. But even in cases where the surgery leads to deficits, many patients are able to recover. New work on a patient with a post-surgery language deficit highlights the brain’s amazing plasticity in the face of such surgeries.
“Ultimately, a better understanding of what is happening in the brains of patients who go on to have a good outcome from a brain injury, compared to those that don’t, will help develop meaningful interventions that can facilitate recovery where it might not otherwise have occurred,” says Alex Teghipco of the University of Rochester, whose poster on this new work won a people’s choice award at the CNS annual conference in New York.
“It’s incredibly humbling to see someone with a serious disease dedicate their time to research. Patients are incredibly generous with their time, even as they understand that their participation in such studies may not directly affect their own care, but rather improve our understanding of brain function.” -Alex Teghipco
The focus of his work is conduction aphasia, a language deficit that involves difficulty repeating language that is heard. In this rare form of aphasia, patients can speak their thoughts clearly and understand what is being spoken, but will have great difficulty repeating speech, Teghipco explains. “Recovery from conduction aphasia may offer an interesting window into the brain’s ability to functionally rewire itself after injury, which has implications for many other types of brain disease.”
As part of the NIH/NIDS-funded study, Teghipco and colleagues studied conduction aphasia in “patient AE,” a man in his mid-to-late 20s who underwent surgery to resect a large tumor in the temporoparietal region of the brain. AE had no discernible language impairments before surgery but during the surgery, he developed a conduction aphasia. This was identified immediately, as the patient was performing language tasks as part of an awake functional mapping of his brain during surgery. The conduction aphasia persisted for weeks after surgery and then slowly resolved over 3 months.
Removing the tumor entailed removing large portions of the left arcuate fasciculus tract, a white matter tract connecting Broca’s and Wernicke’s areas in the brain (areas key in speech processing). By looking at changes to this tract at different points in time and comparing the results to healthy controls, as well as looking at changes to connectivity in his language network, they determined that there was little to no recovery of the left arcuate fasciculus tract as his repetition abilities improved.
So what led to his recovery? The researchers found higher connectivity to the right hemisphere after surgery, suggesting that his recovery was due to the recruitment of right hemisphere regions and their increased functional connectivity to left Broca’s area. “These results are exciting,” Teghipco says, “because they highlight an impressive degree of plasticity in the brain and the importance of the right hemisphere, even in a largely left lateralized cognitive ability like language.”
Working with patients like AE is rewarding, he says, as the longitudinal nature of the work enables a strong relationship over time. “It’s incredibly humbling to see someone with a serious disease dedicate their time to research,” Teghipco says. “Patients are incredibly generous with their time, even as they understand that their participation in such studies may not directly affect their own care, but rather improve our understanding of brain function.”
Here’s the full list of CNS 2016 people’s choice poster winners:
Session A: William Curley, “EEG Evidence of Command Following in Patients with Severe Brain Injury”
Session B: Alex Teghipco, “Recovery from conduction aphasia depends on contributions from the right hemisphere: A case study”
Session C: Christina Bejjani, “Cognitive Appraisal of Threat Influences Striatal Response to Negative Feedback”
Session D: Kurt Winsler, “Investigating the Role of High and Low Spatial Frequencies in Written Word Recognition: Evidence from ERP Masked Priming”
Session E: Natalie McCormick Miller, “Language facilitates tactile discrimination”
Session F: Aaron P. Jones, “Contribution of Far Field Effects of Cortical tDCS in the Cerebellum to Learning in an Object Detection Paradigm“
Each winner received $100, kindly awarded by Elsevier.
-Lisa M.P. Munoz
