Vision Restoration After TBI

1. Vision Restoration After TBI • Vision deficits after TBI are very common. • A procedure called a vitrectomy is being used to restore vision in those who were left blind/partially blind. • Before the procedure, patients reported barely being able to detect a hand being waved in front of their face. After the procedure, most had perfect vision.

3. WHAT IS A VITRECTOMY? • A vitrectomy is a surgical procedure to remove the vitreous humour in your eye, along with any floating debris, and replace it with a saline (salty) solution. • A vitrectomy may be recommended as a possible treatment option if you have floaters -small shapes that some people see floating in their field of vision - that don't improve over time, or if they significantly affect your vision.  • However, vitrectomies are rarely carried out due to risks associated with eye surgery, and the procedure may not be available on the NHS. • Before having a vitrectomy, your eye will be numbed with a local anaesthetic.  • During the procedure, the vitreous humour will be removed from the vitreous body of your eye and replaced with saline solution.

4. 'These patients often have other issues related to brain injury, and we can't work on the eye until a patient has stabilized,' said Dr Rajendra S. Apte at Washington University School of Medicine. 'It was important to learn how long we could wait to operate without having a negative effect on vision.

5. It’s worth the wait… Scientists found that 'In the majority of cases, it appears vision can be restored, even if the surgery is done several months after a traumatic brain injury.'

6. Fingerprinting Your Brain • Scientists have thought for a long time that “structural connections in the brain are unique to each individual person.” • These connections are SO unique that researchers at Carnegie Mellon University have discovered that each person’s brain can be “fingerprinted” and therefore identified by its structural connections.

7. Non-Invasive, Diffusion MRI = the Inkpad (Sort of…) Conventional or “older” methods of imaging were only able to estimate the integrity of a single structural connection at a time. Using this new approach, enough information can be captured to estimate the integrity along each separate segment of those structural brain connections, making recognizing patterns much easier.

8. Proving Uniqueness! • Over 17,000 identification tests were run, and with nearly 100% accuracy and scientists were able to tell whether 2 local connectomes, or “brain fingerprints,” came from the same person or not. • “Additionally, they discovered that identical twins only share about 12 percent of structural connectivity patterns and the brain’s unique local connectome is sculpted over time, changing at an average rate of 13 percent every 100 days.”

9. Why is this so important?? "The most exciting part is that we can apply this new method to existing data and reveal new information that is already sitting there unexplored. The higher specificity allows us to reliably study how genetic and environmental factors shape the human brain over time, thereby opening a gate to understand how the human brain functions or dysfunctions," said Fang-Cheng (Frank) Yeh, the study’s first author and assistant professor of neurological surgery at the University of Pittsburgh.

10. Brain Implants • Implants have been being surgically inserted into the cortex of the brain for years. • They stimulate neurons to target specific cells in the body. • What’s the problem with them? • The older implants are electrode-based meaning they rely on electrical connection between a metal plate, the implant, and the nerves around it. • These devices often wear down easily becoming less effective over time and the metal plates often corrode. • A direct connection between the metal and the brain has also leads to problems.

11. What’s New? • Micro Coils! • They are teeny, thin wires with a sharp bend in them that use magnetic energy to stimulate the brain – similar to an MRI. • These new devices should not only last longer but also allow for much more “fine-tuned” muscle movement/stimulation AKA making the implants in general more effective. • “A coil might give some advantages because we can target a narrower area of the brain. So we could target it on a single fingertip, for example,” says Fried.

12. This is very exciting news for implant control prosthetics: • Conventional implants can only target groups of neurons, essentially all the neurons in the area it comes in contact with. • Micro coil implants are able to narrow this down and are able to target specific groups of neurons

13. Resources • http://www.cmu.edu/dietrich/news/news-stories/2016/november/brain-fingerprint.html • http://www.dailymail.co.uk/health/article-4025022/Patients-left-blind-devastating-brain-injuries-undergoing-routine-eye-surgery.html • http://www.popsci.com/tiny-brain-implant-could-help-paralyzed-people-manipulate-prosthetics-more-precisely