Williams Syndrome

In the July 8 New York Times Sunday Magazine, David Dobbs reviews aspects of Williams Syndrome in "The Gregarious Brain". As others have done, he uses Williams syndrome as a springboard to discuss the genetics of personality, neuroscience, and even the evolution of language.

Williams Syndrome brains are on average 15% smaller than normal. A disproportionate amount of this discrepancy is accounted for by smaller dorsal regions. Ventral regions are denser in synaptic connections. Their affability has in part been linked to their lack of connection between the orbitofrontal cortices and amygdylae when interpreting menacing faces. Therefore they know no social fear.

The link between language and sociability, which Williams seems to demonstrate, provides support for the social-brain theory. It states that human neocortex increased to deal with larger social groups. Across primate species the size of the neocortex correlates with the size of the social group. In this theory language was a neocortical adaptation that allowed the maintenance of a large social network without physical grooming; instead relationships could be cultivated with verbal grooming.

fMRI as Lie Detector

Margaret Talbot takes on fMRI and the history of lie detection in her article "Duped" in the July 2, 2007 New Yorker. One company is touting fMRI as a way to exonerate the innocent and damn the guilty. The number of problems with this modality are numerous. One of the major problems is that sociopaths and hardened criminals have brains that respond to lying differently than normals, i.e. they lack pathways that reinforce remorse and guilt.

Intelligent Design

Not one to pass up flogging a scourge, Richard Dawkins takes on Michael Behe's new book The Edge of Evolution in the New York Times Book Review today. In the review, Dawkins defends science instead of proclaiming atheism or attacking religion. It seems that this is the best way to defend evolution and discount intelligent design: ask where's the evidence and where's the consensus? Dawkins rightly points out that Behe's stand has created a lucrative niche for himself on the speaking circuit. His books have surely found an audience.

Klippel-Feil Anomaly

This condition is a concern to neurologists because the anomaly, congenital fusion of cervical vertebrae, can sometimes have neurologic consequences. The vertebrae aren't actually fused; they fail to segment normally between the third and eighth weeks of development. On examination these patients have short necks, low hairlines, and limitation of neck movement. A recent example had one shoulder lower than the other. The picture in Bradley and Daroff (from where all information is borrowed and adapted) seems to demonstrate the same. Imaging reveals the fused vertebrae. Compression of nerve roots, cervical spinal cord, or vertebral or spinal artery can occur. Interestingly, suspected incomplete decussation of corticospinal fibers can cause mirror movements in children. There are many associated abnormalities, including bifurcated spinal cord. Many patients do just fine. The patient I saw had two discrete transient events characterized as right hand, lower arm, neck and face tingling. Neuroanatomically these events were difficult to ascribe to his K-F anomaly. DWI was negative. There was no history suggestive of an epileptic or migrainous phenomenon.

Music

The author of This Is Your Brain on Music is perfectly poised to write a book about the neuroscience of music. Daniel J Levitin began his career as a musician and sound engineer, and later he passed into academia to better grasp the science behind music’s appeal. His dual interests, music and neuroscience, and their interplay seem to appeal to many others, as evidenced by the book’s ubiquity in like-minded media outlets over the last few months. (Try here.) This likely also reflects the fact that he has written a book comprehensible to those without any music or science training.

The book does not present a cohesive theory for how music is processed in the brain, in part because there isn’t one. Levitin’s fragmentary approach reflects the fragmentary nature of the field. But even the fragments are intriguing. Music first activates the auditory cortex. Then areas adjacent and overlapping with Broca’s interpret musical syntax. Finally the meaning of the music (the musical semantics) is delineated in the mesolimbic system, including regions near Wernicke’s area. This is hardly the whole story. The cerebellum (10% of brain weight; 50-80% of neurons) possesses direct connections from the ear. Through its connections to the basal ganglia it is implicated in rhythm and meter. How all these linkages are coordinated into the experience of music is less clear, but Levitin surely puts many of the pieces on the table.

Levitin introduces a few diseases that offer insights into the neuroscience of music. Those with higher functioning autistism are drawn to the structure of music but they miss the emotional appeal. Perhaps this is a result of their smaller neocerebellums. On the other hand, people with Williams Syndrome have larger neocerebellums and are musically gifted. Levitin casts his net wider still. Citing work done by Schmahmann et al regarding the cerebellar cognitive affective syndromes, he associates socialibility and musicality.

In later chapters, Levitin takes a more psychological approach as he explores the genesis of musical preference and the nature of expertise. In the last chapter he dives into evolutionary psychology. Where this fits into the overarching purpose of the book is not clear. Levitin supports the idea that music, or traits that endow musical ability are present today as a result of sexual selection. Here is not the place to deconstruct each of his arguments for this position. This has been done by many critics of evolutionary psychology. What is more interesting is why intelligent thinkers insist that certain traits exist as the consequence of selection, either sexual or natural. Perhaps the mantle of natural selection bestows prestige and lends credence to an area of research. Regardless, the evolution of music and musical ability as the result of sexual selection is unprovable, and moreover, it does little to advance our understanding of why some music sounds so good.

Chronic Headache

Those unfortunate to suffer from chronic headache present quite a quandary to neurologists. However, the physician can go home without persistent pain in his head. Some of these patients are curable, but many of them will not respond to therapy. This proves as frustrating to the patient as to the doctor.

A Head Case by Michael J. Nelson in the June 10, 2007 New York Times offers a brief account of one patient's (the author's) experience with chronic headache. He tries a number of medications without any relief of the headache that has plagued him for twenty years; he does experience unsettling side effects. In an act of desparation he tries novicaine scalp injections which leave him with worse pain.

This account is matched by many similar experiences of chronic headache patients. Careful, almost algorithmic approaches by enthusiastic headache specialists can yield results, but chronic pain is chronic for a reason.

Pseudoseizures

The confusion in terminology surrounding this condition seems to reflect its complexity.

Oftentimes they are diagnosed in patients who have epilepsy. Along with their epilepsy they may have abnormal interictal EEGs and/or abnormal brain imaging. Therefore it becomes necessary to capture the problematic spells with an EEG to determine whether increasing or adding other antiepileptics is prudent. Usually this has already been done and not worked before a patient is admitted for EEG monitoring.

Capturing non-epileptic spells puts the physician in an uncomfortable position. To sort out what the genesis of the often medically refractory spells is requires a bit of deception. Usually the characteristics of the spells indicate to the physician whether a spell is epileptic or not. The bind is that without capturing these one can never know for sure whether they are epileptic. Unlike other psychogenic symptoms, Viz. other manifestations of somatoform disorders, pseudoseizures can be documented with a normal ictal EEG. For pseudoseizures, there is a test to prove that the somatoform disorder is not real or organic. I think the deception - if there is any - enters when the physician directs testing to gather evidence against the patient. Of course this could be viewed otherwise. By proving that the spells are not epileptic a patient can be spared potentially toxic medications and medical care not directed at the underlying problem, one more psychologic or social.

This post previously detailed what I am calling deception taken to its greatest extent. I previously didn't have a discussion of the difficulty inherent in diagnosing and treating pseudoseizures, nor did I state the unsavoriness in the following interaction. An attending told a woman with suspicious spells that he was not going to make her angry, which triggered her typical spells, but that there was another possible way to induce a seizure. A alcohol pad on the neck could cause a temperature differential and a convection that might induce a seizure. One alcohol pad was not enough so he added another. The woman became unresponsive and then began shaking. The attending took off the alcohol pad and wiped her neck with water. She stopped within a couple minutes and was very lethargic.

The most disturbing thing about this is that in identifying the spells as non-epileptic, the neurologist can walk away without having really helped the patient. The most important part of the pseudoseizure hospital admission is when the physician addresses the pseudoseizures and involves therapists and possibly psychiatrists in the patient's care. This is usually a very difficult conversation, but when done with compassion and understanding, it can be therapeutic.