Tuesday, April 29, 2014

WILTIMS #143: No phobias? We can fix that.

Today's lectures were rather different from the usual dry science. The first of our two behavioral science lectures was on death and bereavement. Though it was a fairly well done presentation and the short documentary on a young doctor who died of terminal cancer was riveting, my biggest personal takeaway was of how stoic I've already become when dealing with end of life issues.

Whereas several of my classmates were clearly emotionally affected by the stories, my already plentiful experiences around the dying and grieving have given me great practice feeling sincere empathy without becoming distraught.

My first clinical experience over 5 years ago (is that all?) was in an ICU, the unit where it's said patients go to die. Watching a child die and the parents grieve in the PICU was one of the most impactful experiences of my life. Then during treatment for cancer and while subsequently volunteering in an oncology office, I saw another side of death. I watched a friend's personality slip slowly away while their significant other had to grieve far before the funeral. Death can be both tragic and a relief.

I don't look forward to having to deal with patients inevitably dying under my care, but I take solace in the knowledge that I won't be going into that situation blind to the emotional impact.

The other topic of the day was cognitive and behavioral psychology. We spend much of our time discussing old researchers, their theories, and the dubious ways they tested them. The most interesting (and horrifying) was the story of Little Albert. That was the name of a baby boy who was conditioned to have generalized phobias.

Essentially, they showed him a whole slew of animals and objects, none of which he was fearful of initially. They then made a scary noise whenever he was shown a white rat. The kid then became fearful of not just rats but other animals and animal-like masks as well. Needless to say, this experimental setup would never EVER be approved nowadays.

TIL: A lateral cerebellar lesion can cause an intentional tremor. Intentional tremors differ from the non-intentional tremors seen in Parkinson's, because they are associated with the planning and coordination of movements rather than the initiation of said movements.

The habenular nucleus of the epithalamus is located between the pineal gland and posterior commissure.

Monday, April 28, 2014

WILTIMS #142: Hypothalam-THIS!

Eat, drink, be merry, and reproduce. ~The hypothalamus

Well today was brutal. We had a 2½ hour, 100 question exam on behavioral science and then an hour lecture on the hypothalamus in neuroscience. I'm not sure if anyone made it more than 15 minutes into the neuro lecture without their brains turning to jelly.

But all was forgiven when we stowed the notes and ventured into the intrepidly shining spring sun to play some kickball and touch football. A little running around goes a long way towards exorcising the multiple-choice demons.

TIL: In the hypothalamus of the brain, the tuber cinereum becomes the median eminence which becomes the infundibulum. That's three named regions for a stalk less than a centimeter in size. Yay neuroanatomy!

Friday, April 25, 2014

WILTIMS #141: Fern of Life

Quote of the day:
"Any questions?"
"Then I've lost you already..."
"Well, it only gets worse."

TIL: Whereas the folds of the cerebral cortex are called gyri, folds in the cerebellum are called folia (as in foliage, or leaves). The branching white matter is called the arbor vitae, or tree of life. Amusingly, when checking this out on wikipedia, the critique is brought up that it really looks more like a fern. Apparently either botanists or anatomists are very strict with their metaphors.

The law (and possibly morality?) requires that physicians maintain confidentiality even if someone confesses to murder. Once a deed is done, and you have no proof that they will immediately hurt someone else, you, as a physician, are required not to report the patient to the police, even if there is an open investigation into the crime. The idea is that a doctor's first responsibility is always to his or her patient. However, if they are planning to hurt someone, then all bets are off.

Thursday, April 24, 2014

WILTIMS #140: Happy, happy fun times! /s

Apologies for the rather dreary facts today, but when the topics covered are substance abuse and eating disorders... it's hard to spin into cheery tidbits. Here's hoping tomorrow's more upbeat!

TIL: Anorexic people are often very spiritual. This allows them to be unconcerned with death; it would only mean losing the part of them they don't like.

40% of people have used illicit substances. ⅔ of current users are between the ages of 15 and 23.

Ecstasy (the drug, not the mood) was create in Germany in 1912 as an appetite stimulant.

Though heroin used to be highly associated with the spread of HIV, cocaine has now taken that dubious distinction. The reason is that people have learned not to share needles, which is how both heroin and cocaine users most-easily spread blood-borne infections. The difference now is, with that mode of infection removed, heroin users simply fall asleep during the high while cocaine users are more likely to have unprotected sex.

Tongue in cheek comment from professor: The only difference between benzodiazepine withdrawal and alcohol withdrawal is the smell.

WILTIMS #139: Hi, my name is Christopher and I have no idea what I'm doing...

Today was my first graded mock Objective Structured Clinical Examination (OSCE), and though less than ideally organised, it was actually a lot of fun! Part of the exam entails interviewing standardized patients. These incredibly experienced actors can portray a patient for both a history and physical exam. Today, we only did the history of present illness and a social/sexual history with these actors. We practiced physical exams on each other (presumably because we are too inexperienced to bother a standardized patient with our poorly aimed prodding).

The goal today was just to practice our communication skills in the setting of an actual fake medical exam room with an actual fake patient. It was nerveracking at first but went surprisingly well. The best part was debriefing with the actors not two minutes after they were so convincingly a totally different person. That I managed to comfortably talk to an actor about his fake chlamydia shows how far I've already come in the last year.

Unsurprising fact of the day: Coffee causes and relieves headaches, depending on the dosage.

TIL: Going to Wendy's is totally good for my medical education. Apparently a former student at my school went to the local Wendy's and discovered in the wall display about Dave, the founder of the burger chain, that he had a compensated fourth cranial nerve palsy. And he actually did!

The fourth cranial nerves (or trochlear nerves) control just one muscle in each eye. If one of these nerves fails, the corresponding eye will be rotated in the socket. To correct for this, a person with a fourth nerve palsy will cock their head slightly to level out the bad eye. The good eye can adjust to this angle, but you have to maintain your head in that position in order to avoid blurred vision.

Smoking is a potent comorbidity for brain aneurysms. Smoker aneurysms are more prevalent, they grow faster, they rupture more readily, and they do worse during surgery and recovery.

Projectile vomiting is not simply puke that travels in a parabolic arc. Projectile vomiting is usually caused by increased intracranial pressure and is characterized by being a surprise to both the patient and physician. There is no nausea and no retching - just sudden, explosive vomit.

Pituitary tumors can cause bitemporal hemianopsia (tunnel vision) and diplopia (double vision), by disrupting the second and third cranial nerves, respectively.

Friday, April 11, 2014

WILTIMS #138: Blobs and interblobs

After an excruciating week of twiddling our fingers and faking productivity, we have finally made it to spring break! I'm looking forward to sleep, relaxation, my significant other, and sleep. I probably won't be posting for the next week or so, but I'll be back for the rest of the third block. Now I'm going to get started on that aforementioned sleep...

TIL: Allodynia is a symptom where normally innocuous sensation causes pain.

Anesthesia dolorosa is a really quirky term. It means painful numbness. So... you can't feel it but it hurts? As counterintuitive as it sounds it totally makes sense biologically. Pain and touch are transmitted by parallel but separate nerves from the peripheral body to the brain, so it's possible to pinch off the nerves for touch (causing numbness) while only irritating the nerves that transmit pain.

Blobs and interblobs are apparently actual scientific terms for structures in the visual sensory cortex. I'd tell you more about them but I was not paying attention in lecture and have no desire to research anything right now. When I find out, I will make sure to share that blob-tastic info with you!

WILTIMS #137: Oooo Doc's got game!

Amusingly, just two days ago I thought I had such a busy day that I would share my impressive schedule with you all. Everything, it seems, is relative. So here is a truly busy day:
  • Give cancer awareness club presentation at local middle school
  • Attend captains' meeting for a spring kickball league
  • Sit on lunch panel for interviewees to our med school
  • Don white coat and take part in a small group patient interview at the nearby behavioral health center
    • with a real life patient!
  • Play touch football for half an hour
  • Play ultimate frisbee for two hours
  • Volunteer at the juvenile detention facility
    • which today turned out to be playing basketball
  • Work on neuroscience presentation for tomorrow
The highlight? There are too many to choose. But one of the better moments was at the detention center. I volunteer there nearly every week and we usually play goofy mental games or do arts and crafts. Every once and a while, we spend the hour playing a sport like kickball or basketball in the gym. It's a lot of fun for everyone and the kids often kick our butts.

Knowing that we were playing basketball this week and that the kids are far better than our usual crew of med students, we brought in some ringers. We invited the best basketball players in our class and a good 6-7 of them actually came.

The kids were waiting in the gym for us with their basketball gear on. As the regular from the club stream in, they look very cocky - as they should be. But then the ringers come in. The looks on the kids' faces were priceless. And the last person through the door is a 6'5 tall guy who was a good foot taller than everyone on the home team.

The game was first to 21, win by two and it was a brutal. Fouls went uncalled and boy were there fouls. Med students barely won 22-20. Everyone had so much fun that, for the first time ever, the guards extended the kids' free time so that we could play a second game. The second game was a little less intense which meant we got some of the girls to play. Everyone had a blast, including our players from the med school. Several of them were interested in coming back to play basketball on their own with the kids.

I love that we get to make the kids' day a little more exciting and that they get to see role models as great as my colleagues.

TIL: A Chiari malformation is a defect of the brain whereby the cerebellum and brain stem are squished through the foramen magnum (literally: great hole) at the bottom of the skull. This can cause all sorts of problems including hydrocephalus and syringomyelia (increased cerebral spinal fluid around the brain or in the spinal cord, respectively).

Thursday, April 10, 2014

WILTIMS #136: Eye see you

You know how at twilight, blue lights seem to have a fuzzy halo (or a fuzzier halo than the other colors (you should get your eyes checked))?

TIL: ...why blue lights always look so blurry! It's a combination of chromatic aberration and our evolutionary attempt to control that aberration. Think of a prism, spreading white light into a rainbow. It does this because light of different colors is deflected differently as it transitions between two substances (with different refractive indexes).

The human eye has two kinds of light receptors, rods and cones. Rods are responsible for seeing in the dark and providing peripheral vision. They only detect one wavelength so we can only see in black in white in very dark environments. The nice thing about rods is that they are found all over the retina, so you have a full wide-angle view.

Cones, on the other hand, only work well in brighter light and come in 3* flavors: red, green and blue. The problem with this is chromatic aberration. The image coming into your eye is bent by the cornea, lens, and various fluids. The three wavelengths separate from each other and project three slightly offset images on the retina. You can see absorbance curves for rods and cones above. Can you tell which one is the odd color out? Blue! When your eye focuses light on the retina, it does the best it can to minimize the aberration, so it focuses somewhere between the focal points of the red and green cones and just ignores blue.

So why don't you see blurry blue things all the time? To attempt to counteract its shoddy focussing, the retina messes with the distribution of the different color detecting cones. Whereas rods are all over the place, cones are almost entirely in the center of the eye, called the fovea. But blue cones are both less prevalent throughout the retina and not present at all in the center of the fovea. Your brain does some photoshop magic to make sure you think blue things are blue even though you don't directly see blue in the center of your vision.

So when lighting is dim and cones are strained, blue gets the shortest end of the stick. And that is why blue lights look fuzzier than other colored lights.

*There is actually a fourth human cone that can detect yellow wavelengths. It's absolutely fascinating but frustrating to talk about because we don't have words to describe what these people see. There's a great Radiolab podcast on it. Also, human eyes have nothing on the mantis shrimp.

Wednesday, April 9, 2014

WILTIMS #135: A busy day in the life of me

Today was a busy day. Here's the rundown:

  • 3 hours of lecture
    • Behavioral science on childhood development
  • Lunch
  • Neuroanatomy lab
    • Poking brains and reading MRIs
  • Pick-up soccer game
    • Playing with upperclassmen and a surgeon from the medical center
  • Surgery interest club
    • Literature review (and free food) in the surgery lab at the hospital
Last night my apartment also hosted a late season interviewee, which was a nice reminder of how lucky we are to have made it to this stage.

TIL: Sigmund Freud never actually studied any children when coming up with his theories on child development. Take from this what you will...

Object permanence and object constancy are slightly different concepts. Permanence is the acknowledgement that objects exist even when unobserved (i.e. "Where'd the ball go?" gets much less interesting). Object permanence usually develops between 8 months and 1 year of age.* Constancy is the maintenance of a consistent mental idea of an object or person (e.g. Mom is Mom not some random lady).

* Amusingly, object permanence was debatable in my college-level intro to philosophy class. How can you be certain that all of existence doesn't disappear when you aren't sensing it?

Tuesday, April 8, 2014

WILTIMS #134: May the (inertial) force be with you!

TIL ...how Star Tours works! Your brain/ears can't distinguish between forward acceleration and upward tilt. So when you jump to "lightspeed," they just tilt the entire craft backward and your simple brain, expecting to go forward and not seeing anything to confirm that you
're tilting, happily goes along with the illusion.

The malleolus (hammer (or mallet) of the ear) points posteriorly (backward) when viewed from the internal auditory meatus (ear canal).

Hearing should never be asymmetric between the two ears; if it is, that is always significant.

In Waardenburg syndrome, congenital hearing loss is associated with heterochromia iridum (different colored eyes) as both are formed at a similar stage of development.

Caloric nystagmus is a useful diagnostic indicator (and apparently a fun, if wet, cocktail party trick) where you squirt water of different temperatures at each ear while laying down. This causes a convection effect (hot fluid rises) within the horizontal semicircular canal of the vestibular system. Fluid moving within the canals tells the ears that your head is turning, even though it's not, and your brain reacts by pointing your eyes the opposite direction to the perceived movement. The net result on a health person after you squirt water in their ears is that they will feel really dizzy and their eyes will move uncontrollably away from the warm water ear.

Saturday, April 5, 2014

WILTIMS #133: That's not punny

Attendance in class today was as low as the number of classmates with hangovers was high. Last night was our school's spring formal and each neuroscience professor managed to crack a joke about the impaired brains of our absent colleagues.

TIL: There is an area in the brainstem (the parvocellular reticular nucleus) that controls involuntary movements of facial expression. Since this is a separate tract from voluntary movement, it makes possible some peculiar disorders. When such a person is asked to smile, they can't, but if you tell a joke, they will smile normally - assuming the joke is funny. Don't start accusing people of having brain damage just because they don't appreciate your terrible puns.

The Artery of Percheron is an anomalous formation where the diffuse arterioles that normally supply the thalamic midbrain region are consolidated into one small artery. This is dangerous because a small clot can block this vessel and cause a stroke characterized by an immediate loss of consciousness.

Nociceptor is the term for a pain receptor. The prefix comes from the Latin word for "harm," the same word found in the Hippocratic idiom Primum non nocere - "First, do no harm."

The drug naloxone is an opioid receptor antagonist that can block the placebo effect. This is of special interest because it shows that the placebo effect is not purely psychological but somewhat physiological.

Friday, April 4, 2014

WILTIMS #132: Short coats

Today was the first time we got to go on the hospital wards (psychiatric or otherwise) as medical students. Up to this point when we've donned our white coats and ties/female-nice-clothes (usually not both), patients have been brought to us. It was rather exciting and a dash frightening to be in this new environment. People tend to assume you know what you're doing if you look the part, and looking the part is just about all we are capable of at this point.

In group of about ten, we watched a psychiatric attending interview a patient. Perhaps the starkest indication of our naive inadequacy was our cursory assessment of this patient. He seemed to be doing very well and as the interview concluded we felt pretty optimistic about his prospects. The moment the he left the room, the doctor turn to us and said, "Sadly, the prognosis is not good for him." The disappointment was palpable. Ah well. There were two third years in the room who seemed far more with-it, so give it some time.

TIL: Borderline personality disorder gets its name from being in the middle of the spectrum from psychotic to neurotic disorders.

Thursday, April 3, 2014

WILTIMS #131: I'm droopy... or have a cranial nerve palsy

I thought we already covered cranial nerves in gross anatomy all those months ago. I was wrong. Oh so wrong. The 2½ hours of lecture this morning exclusively on cranial nerves and their associated spinal cord nuclei taught me that the hours spent in gross anatomy were just a friendly introduction to convoluted roadmap of neurons that control an enormous amount of the head and body from a scattered core of seemingly indistinguishable spinal cord chunks. An we still have several lectures to come on eyesight and the optic nerve (CNII).

This afternoon we had a fantastic lecture on the ethics of procreation and genetic testing by this guy. He managed to quickly and objectively sum up the arguments from everything from abortion to cloning to "designer children." One of the more interesting points was on the future of certain technologies and their impact on the long held ethical beliefs of all parties involved. How does the debate over abortion change one we create the artificial uterus? That's not ridiculous to think about considering how medical science has continued to push back the limits of premature viability and push forward in vitro early embryonic development.

TIL: One of the cranial nerve exams is to have the patient sick out his or her tongue. If it deviates to the right, either the upper motor neuron of the left hypoglossal nerve (CNXII) or the right lower motor neuron has been damaged.

Along the same theme, because the upper portion of the face is innervated by both sides of cranial nerve VII but the lower muscles of facial expression are innervated purely contralaterally (from the opposite side), if you have a left upper motor neuron lesion you will have a droopy lower right face, while a lower motor neuron lesion will result in a Bell's palsy (half face droopiness) in the ipsilateral side.

If one of the abducens nerves (CNVI) is damaged, it will result in double vision that resolves if the patient turns his or her head. The troclear nerve (CNIV) also causes double vision when damaged resulting in a short of twisting of the eye within the socket. Patients can cancel out the distortion by awkwardly tilting their heads.

"Brain birth" is a concept analogous to brain death accepted by some proponents of abortion rights that states that, just as adults who have been rendered irreparably unconscious are declared legally dead before their heart and lungs have stopped working, unborn fetuses should not be considered alive until the brain had developed enough to be meaningfully useful.

Wednesday, April 2, 2014

WILTIMS #130: Metaphorical iceberg off the starboard bow!

Well, I survived at least one of yesterday's tests (further grades pending)! Thankfully we have no more exams until after spring break. I don't think I've ever anticipated a spring break as much as this one. I'm not going anywhere terribly interesting or planning any rowdy debauchery, but just sitting/sleeping for a while sounds amazing.

Freud's iceberg metaphor for the mind
Today in Behavioral Science we started talking about psychoanalysis, including Freud's id, ego, and superego. Amusingly, the last time I learned about Freud was in the hardest class to explain on my college transcripts: German 187: Satan in German Literature. This was taught in English, not German, and basically consisted of watching horror films and pretending like there was some connection with legitimate academic thought. Bizarre interpretations of Freud came up frequently. I somehow got upper-division writing credit for this and (to my knowledge) not one med school challenged me when I used this as one of my writing prerequisites. Good times.

TIL: While denial, distortion, and projection are considered narcissistic defenses, neurotic defenses include dissociation, displacement, repression, rationalization, isolation, and intellectualization.