Sunday, October 18, 2009

Woman with half a brain and neuroplasticity

Woman With Half a Brain and neuroplasticity

This is an astonishing story that provides strong evidence of the extraordinary plasticity of our brain, which Professor Bartel discussed in class a week ago. It is about a woman who was born with only half a brain. While her parents knew right after Michelle’s birth, that something was wrong, remarkably they did not turn to the doctors until she was about 27 years old. Her mother explains that since Michelle did not have cerebral palsy or Down’s syndrome, they practically had no place to turn. As a result, her childhood and young adult years were incredibly hard. However, she was able to graduate from high school (!), she can speak normally, and she can write and read. Moreover, as the author observes she has an “uncanny knack for dates”. In other words, she can figure out any date in the past or in the future. She demonstrates her ability in the video. Today, she is 37. She works, pay rent and can perform most household tasks.
About ten years ago, the family finally referred to Dr. Grafman, at the Cognitive Neuroscience Section of the National Institutes of Health. He conducted an MRI scan, which determined that Michelle was missing almost all the left side of her brain. The doctors explain that it was most likely lost during a pre-birth stroke. They provide the scan and it looks horrifying! There is virtually nothing there, just a massive black spot on the left. The doctor observes that, while some of the deep structures remain, the cortex is 95 percent gone and the important structures that control movement, behaviour, cognition are missing.
In the video, it is evident that she has some troubles. However, amazingly, she can understand people; she is able to find right words, while speaking; she can construct correct sentences; in short, she is capable of fully expressing herself. The doctor explains that her brain has rewired itself. The right half of her brain took over some of the vital functions that are normally done by the left, such as speaking or reading. However, while the right hemisphere took part t in the development of the language abilities, some of the other skills, for the normal functioning of which the right side is responsible, were lost. For example, Michelle struggles with abstract concepts and might get lost in new surroundings. She has difficulty controlling her emotions. In the video, she herself explicates quite correctly and logically the reasons why she tends to throw fits, temper tantrums. She says the doctor helped her to understand that it happened “because I was missing half my brain”. Obviously, Dr. Grafman keeps on seeing Michelle quite often. He observes that even during these 10 years since her first diagnosis some of her intellectual functions have improved! She will need assistance for the rest of her life, but she is not completely helpless.
Interestingly, although the author observes that Michelle’s story “has turned medical thinking upside down”, the idea that the brain activity associated with a certain function can move to a different location is not new. Actually, it was first proposed as early as in 1892 by a Spanish neuroscientist and physician Santiago Cajal, who once said “Every man if he so desires can become the sculptor of his own brain”. While some scientists believe that his theory of neuronal plasticity is rather ambiguous (F. Stahnisch and R. Nitsch, Trends in Neuroscience, 2002, 25/11), the majority maintains that Cajal’s pioneering work has laid a solid foundation for a modern concept of neuroplasticity.
I think this is an extraordinary story, anyway, and in this regard, it would be interesting to discuss the potential of brain fitness. If the right half of this woman’s brain was able to rewire, reorganize itself and the neurons were able to form new connections, allowing her to regain her ability to speak and read, who knows what a “normal” brain is capable of?

1 comment:

Liana Henkel said...

I find this story fascinating. I watched this video interview and although Michelle has some developmental deficiencies, it was amazing how much she manages a pretty ‘normal’ life with ‘half a brain’. I remember a comment in class - by the time that Parkinsons disease is manifested, approximately 80% of the brain is already ‘non-functioning,’ but the brain keeps adapting to maintain functionality until it reaches this point that it can no longer sustain.

The discussion about the ‘costs’ was interesting - her inability to control her emotions, difficulty with abstract reasoning, or getting lost in unfamiliar surroundings (although I am directionally challenged and can easily get lost until I repeat the travelling route a few times … hmmm). Any way, Dr. Grafman pointed out that in the process of her right brain taking over functions normally associated with the left, such as learning speech and language for example, some right-brain function was lost or perhaps just hindered in some kind of ‘benefit and cost’ balancing. Is there some kind of internal hierarchy within the brain that ‘makes’ those decisions or does the nurture side (of nature versus nurture debate) influence – her school, parents, and siblings would have been exposing/teaching her language and did that nurture environment affect/encourage how the right brain took over specific left-brain functioning.

Michelle has an ‘uncanny’ way with numbers. In the interview, her dad said some date in the future and after a few minutes, she figured out that this specific date would be a Sunday. A skeptic might say that she figured it out ahead of time or might question that ability and who is to know; however, on the route of discovery, any thing we read, hear, or discuss requires a healthy dose of both faith/trust and skepticism.

Dr. Grafman also indicated that she is improving in some of her ‘intellectually functioning’ and although there probably wasn’t time in this video interview to discuss them, it makes me wonder about what possibilities exist for Michelle and other brain/neuro-based disabilities and diseases.

As an aside … I also wondered if I had closed my eyes, if I would have been even more amazed at her abilities. She spoke articulately - clearly and thoughtfully - but part of her ‘disability’ was accentuated by some visual perceptions such as her inability to climb the stairs head on (walked up sideways), and her appearance and mannerisms were slightly similar to other physical attributes of other brain/neuro disabilities, but I stress slightly. It just made me think about how we use all of our senses in combination with prior knowledge/images in our perception of new information and ideas, rightly or wrongly.