30 April 2012

Connections

One cool thing about learning the mechanisms behind disease in such detail is that now, some seemingly unconnected details in a patient history would steer me to a particular diagnosis. Some examples:
-A couple comes to your infertility clinic after trying for a year to conceive, without success. The husband has a poor sense of smell.

Kallmann syndrome involves improper migration during development of those parts of the brain that are responsible for smell and that secrete hormones involved in fertility.

-A elderly man comes into the emergency department of your hospital because of transient blue-green colorblindness after sex.
The enzyme that Viagra (sildenafil) inhibits to maintain erections is closely related to the enzyme in the eye that discriminates between blue and green. In some people, Viagra acts upon both.

-An elderly woman comes into clinic complaining of months of fatigue and unintentional weight loss. The eyes look different from each other, and one of them is yellowed.
The woman has jaundice, a sign of liver dysfunction that presents as both eyes being yellow. However, only one eye is yellow. This means that the other eye must be a glass eye. The single unifying diagnosis is malignant melanoma of the eye. Years ago, the woman had her eye removed because of melanoma. Melanoma of the eye often metastasizes to the liver, sometimes taking years to reveal itself. This metastasis to the liver is causing jaundice as well as her other symptoms.

Poets, teachers, detectives, and comedians perform their crafts by illuminating connections between things that aren't initially obvious to most of us. It's fun that medicine allows for the same thing.