November 3, 2009

Asperger's or Autism Spectrum Disorder

As reported by the New York Times, the future DSM-V will have Autism Spectrum Disorder subsume Asperger's. This change highlights the debate that surrounds any taxonomy: is it better to lump or split? I side with the splitters on this issue. Mild autism or Asperger's is a different entity than severe autism; it's the difference between a college education and the inability to use language in any capacity. Even if Asperger's in under the umbrella of autism spectrum disorder, the separate name implies a difference in prognosis and the response to therapies and treatment.

One other interesting point was alluded to in the article. Asperger's syndrome has only been officially used since 1994, and it is cases of Asperger's and mild autism that make up the majority of the growth in autism over the last couple decades. This is important to recognize as media outlets and advocacy groups often draw attention to the rise in autism, when a large part of the "epidemic" (and maybe all) may be due to increased recognition.

The picture that fronts the article illustrates synesthesia, a trait seen in many non-autistics. I am not aware of an increased prevalence of synesthesia in those with autism.

October 27, 2009

Generalized Dystonia

Watch the video.

Dystonia is a movement disorder that consists of directional, sustained muscle contractions that result in abnormal, twisting postures. There are usually combined contractions of agonist and antagonist muscles. The movements are frequently stereotyped.

Dystonia is also described by the region or regions it involves, a limb, the neck, the face, or in this case the whole body. This latter form, generalized dystonia, is disabling, and usually begins in young people. At 26 years old, this woman is old to develop generalized dystonia, but the onset of her disease is not typical of primary dystonia. Neurologic disorders can be divided into primary diseases and those that are acquired or secondary. Since this condition began acutely and in association with a flu shot - association not proving causality - it should be characterized as a secondary dystonia.

Secondary dystonia has a long list of potential causes, but it is not fully necessary to review them. The initial evaluation of a movement disorder begins with phenomenology. It frames the search for an etiology and the eventual treatment. The video demonstrates one of the features of dystonia: it is frequently activity-dependent, so walking backward and running can be completely normal while walking forward is completely abnormal. One way to conceptualize why this might happen is to consider running, walking forward, and walking backward as drawing on different motor programs. Task-specific dystonia vividly illustrates this idea. In this case, however, the complete resolution of all symptoms with running and walking backward is not consistent with dystonia. Additionally, her pattern of speech is not consistent between interviews and is typical of a psychogenic dysarthria.Here is a more definitive statement from the Dystonia Medical Research Foundation.

This young woman is ill and should be seen by a movement disorder neurologist at an academic center. I mention an academic center because she needs to see a doctor who will be able to take the amount of time with her she needs. And if she is not seen by someone with a practiced eye, she may receive unnecessary and potentially harmful medical and even surgical treatment.

Here's another news account.
This story is certainly not a reason to forgo a flu shot, especially if you're in a high risk group.

Neuron Images

Technology Review published pictures tracing the development of neuronal imaging through time. Starting with Ramon y Cajal, here are two examples of modern imaging techniques. The following is a cortical pyramidal neuron imaged with confocal laser microscopy.
This is a picture of a hippocampal neuron's cytoskeleton after the cell membrane was stripped away with detergents.

October 11, 2009

Bill Clinton and Parkinson's Disease

This story has been bouncing around for a while. I'm not sure when it started but it was given a boost by a visible tremor during his appearance on The Daily Show with Jon Stewart in September 2008.

Bill, 63 years old, may have Parkinson's Disease (PD). The mean age of onset for PD is around 58 or 59, around the time Bill began having his tremor, hardly proof, however. If anything, this episode in the life of Bill offers an opportunity to clear up a few things.

Here's what he had to said on Larry King about the rumors.

He's a politician and not a physician, so understandably some of what he says needs to be clarified.
1. There is no test for PD. It is a clinical diagnosis with tremor as only one component. The tremor is present mainly at rest, but may be present with action. The two other cardinal signs are rigidity or passive resistance to movement; and bradykinesia, small and slow movement. There may be postural instability characterized as imbalance, shuffling, and an increased tendency to fall. If the disease is suspected, there should be an evaluation by a movement disorders specialist or a neurologist. It is not clear if he was evaluated by a movement disorder specialist whose opinion would be more trustworthy since they spend the majority of their time treating Parkinson's.
2. Benign essential tremors rarely begin later in life. By definition they are chronic and slowly progressive without other neurologic dysfunction.
3. Fatigue and stress worsen all movement disorders, essential tremor and Parkinson's Disease included. Whether a tremor is affected by being tired does not play a role in the diagnosis.

A few more points: There are good symptomatic treatments for PD. There isn't a cure. Some genes have been identified, but they still account for the minority of patients. Motor symptoms in Parkinson's often present asymmetrically. Masked facies or decreased facial expression is a symptom frequently encountered. It has been suggested that Bill's facial expression is decreased. Tremor-predominant Parkinson's Disease (which would characterize Bill's symptoms) has the mildest, more benign course.

Another blog post about this topic (with some misleading comments hopefully addressed above). Without an exam it is difficult to be sure whether our former President has Parkinsons's or not, but there are elements of his history that suggest he may.

July 25, 2009

Neal Cassady

Even in college I was struck with how hyperkinetic the Neal Cassady character in On the Road sounded. He was always moving and yelling and talking. I was reminded of this in The Electric Koolaid Acid Test by Tom Wolfe. On page 359, Neal Cassady is described this way: "He's wound up like a motorcycle, kicking and twitching and ticking and jerking at the knees, the elbows, the head...He's off on a dazzling run of words." Was ticking really ticcing? Perhaps it was all the speed he was taking. To get a good look at him myself, I assumed youtube would have some videos. In Acid Test they are always filming, so it seemed like a fair assumption. There is surprisingly little archival footage available on the web. There is one video of Ginsburg and Cassady talking in a SF bookstore, but the quality isn't very good (at least it wasn't on my computer). The question is whether the energy that Neal Cassady was always interepreted as having was a movement disorder all along.

July 18, 2009

Task-specific Dystonia in Sports

My interest in this subject was piqued by a video of Charles Barkley's golf swing.

There are plenty of other examples on Youtube of the same swing. This is a severe example of what in golf is called the yips. It doesn't have any connection to this restaurant that I am aware of.

By Mayo Clinic staff

Yips are involuntary wrist spasms that occur most commonly when golfers are trying to putt. However, the yips can also affect people who play other sports — such as cricket, darts and baseball.

It was once thought that the yips were a form of performance anxiety. However, it now appears that the yips are an example of focal dystonia, which is a neurological dysfunction affecting specific muscles.

Some people have found relief from the yips by changing the way they perform the affected task. For example, a right-handed golfer might try putting left-handed.

Worsening with anxiety is a classic symptom of dystonia, so the yips are probably more often dystonic movements than this definition states. The yips have been discussed as a dystonia in a Japanese scientific article.(1)

Dystonia is a movement disorder characterized by involuntary, directional (sometimes twisting), stereotyped movements. They are often sustained (longer than a tic) but can be brief. They involve simultaneous contraction of the agonist and antagonist muscles. The movements are frequently worsened with action, thus called action dystonias. Some action dystonias only occur with specific tasks. The most common task specific dystonia is writer's cramp. Task specific dystonias have been described for auctioneering, playing the piano, and playing a wind or brass instruments with abnormal movements of the tongue, lip, and chin muscles.

A free throw dystonia appears to affect Chuck Hayes. The commentators are not very forgiving.The same problem with release can occur in darts, referred to as dartitis. It has been considered a psychologic problem but it is certainly a neurologic one. Here's a severe example.

There is a body of literature regarding musician's dystonias but less about sports dystonias. One paper describes freezing of the arm in shoulder flexion during boule throwing.(1) The Abstract from the article:
During a period of intensive practice, 2 petanque players developed freezing of shoulder flexion impeding boule throwing. This movement disorder was consistent with the diagnosis of task-specific focal dystonia. Polymyography showed that freezing was associated with bursts of low amplitude. In the absence of motor or sensory deficits, a motor apraxia could be considered.

In an animal model of focal dystonia, produced by inducing overusage of a limb, areas of sensorimotor cortex responsible for the particular movement were 10-20 times larger. From this data, it has been suggested that there is decreased inhibition in the cerebral cortex of those with dystonia. Functional imaging studies have shown increased blood flow in the premotor cortex and supplementary area. There may be decreased inhibition of the thalamus by the globus pallidus interna.

Certainly the repetitive movements of musicians or athletes alter topographic representations of motor and sensory fields on the cortex. This remapping somehow interferes with normal inhibitory influences and some individuals are more prone to this than others. Treatment options for sports associated dystonias include, sensory retraining with practiced repetitive stimulation such as Braille, use of sensory tricks, or Botox. None of these have been tried or tested rigrously. Diagnosis could include functional imaging modalities that measure sensorimotor areas in the cortex.

The idea that the cortex is altered by activity is hardly a new one. How much of a role this plays in dystonia is not entirely clear, but task-specific dystonias seem to suggest that in some susceptible individuals, repeated usage results in maladaptive cortical reorganization. And maybe, Barkley's case of the yips, atypical for its proximal muscle involvement, may in part result from his repeated foul throw shooting earlier in life.

1.Tanaka M, Ohyagi Y, Kawajiri M, Taniwaki T, Tobimatsu S, Furuya H, Yoshiura T, Kira J. A patient with focal dystonia induced by golf and presenting a decrease in activity of cerebral motor cortex on task. Article in Japanese. Rinsho Shinkeigaku. 2005 Apr;45(4):304-7.

2. Lagueny A, Burbaud P, Dubos JL, le Masson G, Guelh D, Macia F, Debras C, Tison F. Freezing of shoulder flexion impeding boule throwing: A form of task-specific focal dystonia in petanque players. Movement Disorders 2002;17:1092-5.

July 16, 2009


I left college brimming with evolutionary biology and philosophy and thought I was headed toward psychiatry. Then I read The Man Who Mistook His Wife For A Hat. In that book Dr. Sacks explores the more interesting and outer reaches of neurology through a series of vignettes. In The Anthropologist on Mars his powers are most on display as he describes seven cases in greater detail.

For Musicophilia he took a different approach. There are still the brief case histories, but they are woven into music-themed chapters. Instead of cases standing alone, they are used to illustrate different music-related neurologic disorders. The story about the amnestic musician, first printed in the New Yorker, is an exception: his story is more developed and better reading. In some ways the organization of the book seemed to make sense, but sometimes the links were tenuous, the concatenation of music-related neurology derailing into anecdote. In the two books I mentioned above, the cases stood alone, but here the organizing principle, music, makes the cases seem haphazard, an atonal symphony.

In popularizing neurology, Sacks has succeeded. His contribution to the field largely stops there. His brand of descriptive neurology, at its most developed in Awakenings, has given way to a more scientifically rigorous discipline. There is still room for phenomenology in neurology, but new insights and effective treatments are achieved in the laboratory and in clinical trials. However, in medicine hard science will always have to give way to the individual and more broadly, the social context of disease. Sacks excels in recognizing the individual; he looks beyond the neurologic disease. For this reason, there will always be a place for him in neurology.

July 10, 2009


The synaptic, open, close, close.

June 28, 2009

The Value of Scholarship

An opinion article by Thomas L. Friedman in today's New York Times argues that education, by producing innovators and creating jobs, can lead a country out of recession. I agree that education is the most important investment that a country can make in its future and the future of other countries. His emphasis on education underscored how it is sometimes neglected.

Education can be overshadowed by efforts to increase access to healthcare and provide food. I think this is a disservice when health care is not coupled with education. I argue, albeit without data, that education improves health disparities, decreases birth rates, and tempers religious zealotry. As a rule when aid (usually financial) is considered to develop a country or improve the lives of an underpriveleged group, it should be proportionally directed toward developing sustainable food supplies, providing basic health care, and fostering education systems.

The reality of the world - when a $1 is spent on education, it's not spent on feeding a child going without a meal - creates a real problem for my view, but arguably, the starving child will always be there if we don't fix the system he's born into.

May 31, 2009

Dylan Tics

I just watched Dylan Speaks: The 1965 Press Conference in San Francisco. It's reviewed here. Not to add to the mounds of Dylan commentary generated over the years, but I was struck by the subtle tics throughout the interview. Fine movements of his mouth and eye blinks were the most noticeable to me, but he also seemed to demonstrate stereotypies (lip licking). I think all his movements could be considered drug-induced stereotypies. Having seen him in other documentaries, I had never noted these before. I read that Dylan was using methamphetamines in the mid-60's which would account for these movements. Below is Part 1/6 of the interview which will get you to the rest. It's also available on netflix.

March 28, 2009

An update

In an effort to treat a difficult topic more sensitively (and to address the concerns of a commenter), I edited a prior post.