Traumatic Brain Injury: The case JS

JS was born in 1974. At the age of 9½, she suffered injuries in a car accident in Israel. She broke her left arm and underwent a small skull injury above her left eyebrow. The top CT images were taken in  February 1984 at Rambam Medical Center, Haifa, Israel. They demonstrate acute left frontal skull fracture.
After her recovery, she continued school with success, but slight anomalies remained. First, her left arm did not regain full functionality, although she could use it normally for most purposes. Second, she began to exhibit inappropriate behaviors that became more apparent the older she grew. In addition, making progress in school caused her more effort than before the accident. The family underestimated the relevance of these symptoms. Neurologists declared her fully recovered, and also for her arm no further measures were taken.
„… experienced conflicts with staff and faculty, and in fact, currently is under a no-contact order with a number of faculty. They identified the conflicts mostly as problems of inappropriate social behaviour; belligerence; misunderstanding of simple social cues; and generally very odd and erratic behaviour, such as sleeping outdoors or in public areas, even when she had housing. …” (The Dean of Students, St. Olaf College, MN)
JS continued her education and graduated in 1998 from St. Olaf College (MN) with a degree in Mathematics (see, however, the excerpt above). Her family situation was bleak. Her parents had divorced already before the car accident, and her mother had died in 1996 of cancer. She was left on herself with her sister (4 years younger than her). In 2004, she received her first MRI scan at the Hennepin County Medical Center (MN).

The result came as a shock to JS: Encephalomalacia in the left frontal lobe and mild T2 hyperintensity within the left middle frontal gyri. These anomalies were minor but consequential. They partly (if not fully) accounted for the behavioral anomalies that had prompted this imaging investigation. In the following years, JS received social security support, first in Minnesota, later in California (where she had spent most of her childhood and part of her youth).
Unable to decide on her further living, JS began to travel the world. Although mentally handicapped, she was able to profit from high cognitive aptitudes and skills. Grown-up as a bilingual (English & Hebrew), she easily acquired further languages: French, Portuguese, and starting with 2006 German. In 2006, we met in Vienna (Austria). At that time I was in charge to organize in Austria the International ‘Brain Awareness Week’ of the ‘Dana Alliance for the Brain’. JS found us in a DANA magazine and on the internet and offered to donate her brain for research purposes. Insecure how to react to such a sinister offer, we replied that at least we would have to wait for her death… When she arrived at Vienna (to learn German, as she said), I quickly found out that she was not about to die so soon at all. As a brain researcher, I became interested in her case. I was perplexed by this coexistence of a highly functional personality with subtle behavioral defects that become apparent only upon closer attention. JS asked me to explain to others, what kind of defects these are. This is the reason for this text.
So: what kind of mental defects JS is suffering from? To understand these defects, we need to delve into the functional architecture of the human brain. This is the most complicated of our organs, nevertheless great advances have been made in the exploration of its functioning, also thanks to the careful observation of cases like JS. What exactly happened to JS’s brain on February 25th in 1984, when the car she was in on the back bench left the road so unduly and fell 10 m into a ditch? The medical exposé of the Rambam Medical Center in Haifa where the victim was rushed to reads as follows:
Deep wound on left forehead, from eyebrow to parietal area, pulsing dura exposed, subdural air. Operated under general anesthesia, small tear in dura, minimal contusion below. Wound closed without reconstruction of skull defect. Superficial consciousness for 2½ days. Release after 8 days, no overt neurological deficits.
This last remark stirred hopes in the family that JS, then 9½ years old and such a beautiful and charming girl, would have been lucky and would recover fully from this severe incident. But the neurosurgeon should have known better. He had seen pieces of broken bone, subdural air, and the small tear in the dura. These observations leave little doubt that the injury had affected not only the skull but also the brain tissue below. And behind the eyebrow lies the orbitofrontal cortex, getting its name by its tight contact with the orbit, the bony cavity harboring the eye. It is no surprise that another deficit remaining from this injury was a partial loss of eyesight on the left side.
The orbitofrontal cortex belongs to the ‘prefrontal cortex’, the ‘pre-‘ indicating that this area lies ahead of those frontal areas that are responsible for our motor and sensory functions. Lesions to one of these anterior regions have no overt consequences on motoric or sensory functions. On first glance, the patient may appear unaffected. A famous historic example is Phineas Gage who in 1848 lost his left eye and parts of his left prefrontal cortex at the age of 25 during a working accident. Against the common narrative that Mr. Gage after the incident had turned from a decent gentleman into a bad-mannered, hard drinking and highly unreliable villain, the injured recovered astonishingly well, serving for 8 years a demanding job as a long-distance stagecoach driver in Chile. The injury of JS is much smaller and more localized. The accident did not result in a loss of brain tissue, but disconnected parts of the left orbitofrontal cortex from its regular addressees. Which connections have been affected in detail cannot be told from the structural MRI scan. In addition, we still do not fully understand all functions of the human orbitofrontal cortices (furthermore, the left and the right one seem to serve slightly differing tasks). As a preliminary working hypothesis, the neuroanatomical position of these gyri suggests a role in connecting the prefrontal cortex to the so-called ‘limbic system’.
The different parts of the prefrontal cortex occupy the highest level in cerebral information processing, not under direct sensory or endocrine influence. Their genuine task seems to consist in overseeing and coordinating lower level activities. Therefore, they are often said to harbor our reason. Since the orbitofrontal cortex sustains connections to the limbic system mostly dealing with emotions like joy, anger, fear, sadness and disgust, it is assumed that this high level area somehow integrates our feelings into reasonable thinking. Thanks to reasonable thinking, we can resist impulses telling us to immediately follow our actual spontaneous inclinations. For example, it will be wise to treat our neighbor politely, then he will probably be helpful if we get in trouble. Reason acts with foresight and is able to withhold the reasonable from giving way to attractions leading to transient rewards with unfavorable long-term consequences. The most important addressee in the limbic system for the orbitofrontal cortex seems to be the amygdala. The most prominent feeling elicited by amygdalar activity is fear. Undisturbed interplay between the amygdala and the orbitofrontal cortex informs our reason about the emotional (negative) value of a fearful face. If this interplay is handicapped, the afflicted has difficulties to attach emotional value to impressions that normally would be classified as fearful. Social learning is at the heart of our behavioral development. Children strongly depend in their habit formation on social feedback. They have to interpret continuously social cues as positive or negative, disclosed to them often in casual and informal settings. Smooth interplay between the prefrontal cortex and the limbic system provided, these social interactions will occur without much effort or the need to pay focused attention to them.
Having laid out these – in part still speculative – neurobiological background, we might now be in the position to understand, how a rather limited lesion in the left orbitofrontal cortex should lead to difficulties to comply with social norms. If the lesion occurred at some later stage of development (as in the case of JS at the age of 9½ years), many basic habits have already formed. They probably will persist although it is not totally clear to which extent their persistence depends on the continued input of information. On the other hand, many habits typically acquired only during puberty and early adulthood will be much more difficult to form. It will not be sufficient simply to see an angry face as guidance into the complex realm of dos and don’ts. New habits in compliance with social norms will only form upon patient and often repeated explanation and logical argument. We cannot take the easy way from the limbic system to reason, going by the amygdala and the orbitofrontal cortex. This path is not fully operating in JS’s left hemisphere. If others understand some social relationships and facts of increasing complexity by a simple, less than friendly glance, JS needs the full program: proof or disproof, detailed material, majority and minority opinion, examples, exceptions, and so forth. For her social contacts, this disposition may in the long term be tiresome and irritating. Probably she will have problems making friends, but more sincere friends may appreciate her serious and diligent approach to matters of some­times daunting complexity. She has no fear of complexity, even if surrounded by warning social cues. The prefrontal cortical areas in JS’s brain are very well in the position to fulfil their internal functions, even if one of them is not working well. Sometimes, it may even be of advantage if the ‘traffic between reason and feelings’ is not running so smoothly. Then, the intact rest of the prefrontal cortex can deal with matters without being disturbed by emotions (which all too often are of transient or even redundant significance). This sometimes allows JS to accomplish impressive feats requiring a high level of deliberation and synthesis.
Let’s have Brita a final word on JS, a sincere friend during her time at St. Olaf sharing a room with her back in the 90ies (the comment is from June 06):
“…her priorities and the way she thought about things were unique… She particularly had trouble with authority figures when she conflicted with them… I also noticed that she would learn in unique ways as well. She excelled in anything that required memorization or detail oriented work, but things that required integration of information was baffling to her. I remember talking to her about a French class we were taking together. She was having a very difficult time reading a book in French because she would have to stop and define every single word that she didn’t know. She was unable to figure them out from the context, or get the gist of the story even though her vocabulary was far above average. … She is exceedingly logical and has a hard time identifying or understanding her emotional world. Everything must be explained and explored to a great degree before she is comfortable with it. …”
MLB 07 - 21

The silent interpreter (2/22)