Monday, May 30, 2011

Illinois Lawmakers Pass Concussion Bill

I'm glad to see that my state's lawmakers are addressing the issue of sports-related concussions. The policies adopted by the National Football League appear to be trickling down to the high school gridiron. The bill, passed by the Illinois Legislature, now goes to Governor Pat Quinn's desk for his signature.

Wednesday, May 25, 2011

Population prevalence of the ApoE4 gene

Regarding the Alzheimer genotype, I just did a little research regarding the prevalence of the ApoE epsilon 4 allele (the allele that predisposes to Alzheimer disease). Depending on the study you read, about 20% of the population has at least one epsilon 4 allele, while about 2% have two epsilon 4 alleles. As you'd expect, having two is worse than having one in terms of Alzheimer risk. I should add that the epsilon 4 allele also predisposes to a worse outcome in recovery from traumatic brain injury and is also over-represented among those football players who suffer from Chronic Traumatic Encephalopathy.
 

It's important to note that this data applies only to those of European ancestry. The rates of other ethnic groups are different. I saw one study showing, for example, that the rate of epsilon 4 prevalence is much, much higher among Australian aboriginal populations.
 
I recently sent in a saliva specimen to 23andMe.com to have their CLIA-approved lab run a genetic profile on me, which will include a report on my ApoE status. The service has dramatically decreased in price in recent years, so I finally broke down made the purchase. I'll report those results when I get them next month.

Friday, May 20, 2011

The Timeless Dr. Adelman

Lester S. Adelman, MD
I was recently sent this 1992 essay written by Dr. Lester S. Adelman, retired neuropathologist at Tufts New England Medical Center. It amusingly illustrates the anonymity in which we pathologists toil:

Pathologists spend their time in the figurative,
and sometimes literal bowels of the hospital.
Even those of us who specialize in the pathology
of the brain occupy this nether region. The
patients who benefit from our brilliant diagnoses
are often as little aware of us as they are of
the hospital laundry.
This life of anonymity has its rewards. Frozen sections
are only rarely done on nights and weekends, and straightforward
cases are disposed of quickly. The intellectual and
visual pleasures of the job are great. Every once in a while,
however, we are reminded of the fact that we have given up
a part of doctoring, the part that has to do with knowing the
gratitude of the patients whom we help.
Some years ago, in the era before CT scans and MRIs,
a patient was admitted to our hospital with a brain tumor.
Preoperative radiologic diagnoses in those days were based
on angiography, and this patient's angiogram strongly suggested
a glioblastoma multiforme. The patient was given the
bad news, and a biopsy was done to confirm the diagnosis.
The surgeons also thought the tumor was a glioblastoma,
but when I looked at the frozen section, I discovered the
tumor was clearly a meningioma. With this diagnosis, the
surgeons were able to find a plane of dissection around the
tumor and remove it completely.
I was happy with the outcome and thought I had accepted
the fact that the patient would never know my part .
in it. It was not long after that I was to come face-to-face
with the shortcomings of my chosen medical specialty.
A week later I was at a conference with the neurosurgeons
when I noticed that one of the residents was wearing
an expensive new wristwatch. A moment later I noticed that
a senior neurosurgeon had a similar watch on his wrist. A
quick check of the audience revealed that they all had new
watches!
"What's going on?" I asked.
"You remember Mr. X, the patient with the meningioma?
He's a jeweler, and he was so happy he didn't have
a glioblastoma that he gave us all new watches."
"How about me?" I whined. "I'm the one who cured
him. If it weren't for me, you would have quit, thinking he
had a glioblastoma."
The physicians smiled graciously and conceded this was
probably the case.
Years have passed, and despite the advances in imaging,
my neurosurgical colleagues continue to consult me about
diagnoses. But when I want to know what time it is I still
consult my Timex.

Monday, May 16, 2011

Best Post of January, 2011: Retinal Changes in Inflicted Pediatric Head Trauma

The next in our "Best of the Month Series" is from January 13, 2011:

The illustrious Peter Cummings, MD recently contributed an excellent post to the Cambridge University Press medical blog on the topic inflicted pediatric head trauma.  In particular, Dr. Cummings discusses the presence of retinal hemorrhage as evidence for pediatric head trauma. Whether or not the trauma had been intentionally inflicted depends, of course, on the history provided by witnesses and law enforcement as there are no pathognomonic findings. But, as Dr. Cummings says in his post: "I treat every pediatric case as though it is a homicide until I can prove to myself that it is not."


Retinal fold with hemorrhage
Given the near ubiquity of artefactual retinal folds in extracted eye specimens, I asked Dr. Cummings whether there is a role for postmortem funduscopic examination. He responded that he has had some success with this technique, but postmortem corneal clouding often makes funduscopic exams impossible.
 
Dr. Cummings is the director of forensic neuropathology at the Office of the Chief Medical Examiner in Boston, Massachusetts. He is also first editor of Atlas of Forensic Histopathology, which has just been released by Cambridge University Press.