Neurology 101 -- Huntington's Disease (part 2)

What is any neurology resident's biggest dread? No, it's not getting hammered with 12 admissions in a single night (although that is pretty high up there). Or having a patient code in the middle of the night and not make it. Nope. It's the Neurology Boards. They loom. And at the risk of sounding snotty and crotchety, they ain't the same now as they were when I took them. The Neurology Boards in the mid-late 1990's consisted of a full day written exam, and about 6 months later, if you passed the written, you got the opportunity to take the dreaded oral exam. I understand that the oral portion has been or is soon to be phased out. Lucky residents.

The year I took the Orals, the east coast section was in NYC. We all gathered at the Waldorf-Astoria the day before and got our assignments. I was assigned to Columbia-Presbyterian. That was fine by me, as I was somewhat familiar with Columbia's Neurological Institute. The Oral Boards are split into 3 segments, depending on what your specialty is. I am an adult neurologist, so I had adult and pediatric vignettes and an adult live patient. I won't go into the vignettes, except to say that I cried during the peds vignettes. Damn pediatric neurologists played good-cop-bad-cop and flustered the shit out of me.

Anyway, I would like to tell you about my live patient. My live patient segment was second, in between the vignettes. I went over to the Neurology Clinic and met up with my torturers ... er, I mean examiners. They took me into a little exam room, where a woman was sitting in a plastic chair. She was very fidgety, and initially I thought "why, she's as nervous as I am" which tells you how clouded my thinking was at that moment. The examiners explained to me what was expected and let me interview and examine the patient. I introduced myself and got down to business.

NeuronDoc: "Hi Mrs. X. My name is Dr. NeuronDoc."
Mrs. X: "Hi. How are you?"
ND: "I'm fine. How about yourself?"
MX: "I'm okay, thanks."
ND: "So tell me a little bit about yourself."
MX (clearly agitated) : "I can't do that."
ND (a bit startled): "Why not?"
MX (pointing to the examiners): "They told me I can't tell you."
ND (thinking surprisingly quickly): "Ah. I am sure they didn't mean that you can't say anything. You just can't tell me the name of your disease."
MX: "That's right."
ND: "Let's pretend that this is the first time you are coming to a doctor for your problem, that I am the first doctor you are seeing for this..."

So I went on to interview her. She told me that she was 49 years old, and that her problems had begun about 6 years earlier. She said she was off balance and fell easily. She described feeling edgy and depressed at times. She told me that she couldn't walk a straight line, or remember things as well as she used to. All the while she was telling this, she was very fidgety, shifting around in her seat, futzing with her hair, scratching, moving, rubbing. She wasn't quite 100% with it, and sometimes her answers were confusing. I asked lots of other questions, and eventually got to family history. I asked if anyone else in her family had any medical problems. She told me that her mother, uncle, several cousins, and a grandmother had the same thing she had. Bingo.

After asking all of the appropriate questions, I began to examine her. She had unusual eye movements (slowed saccades), motor impersistence, variable stride length while walking, postural instability, and mild dementia. She also had very obvious, fairly constant, and purposeless movements that, at times, would be converted to a purposeful movement.

Hmmm. Motor impersistence, variable gait pattern, chorea all over the place, and that family history. Well, it basically could only be Huntington's disease. But, crap, I had to come up with at least two other potential diagnoses -- they wanted to hear my top three. Unfortunately, my top 3 diagnoses were Huntington's disease, Huntington's disease, and Huntington's disease. I was completely stuck. Who would have thought that I would come up with only a single diagnosis? I was expecting them to trot out someone with a zebra-disease (really rare and hard to diagnose). But no, they gave me someone with basically only one choice for a diagnosis.

After I finished examining her, the examiners excused Mrs. X, who said "good luck, dearie" and left. I thought thanks, but now what the hell do I do? The examiners turned to me and asked what was my differential diagnosis for Mrs. X. I said exactly this: "My first three choices in the differential diagnosis are Huntington's disease, Huntington's disease, and Huntington's disease. She has all of the classic signs and symptoms of the disease and her family history is consistent with a dominantly inherited disorder. Basically it can only be HD. There are some really rare autosomal recessive disorders that have chorea and dementia, but the disease is clearly dominant. It isn't Sydenham's chorea or post-partum chorea or chorea secondary to lupus. It's Huntington's disease."

The examiners looked at me, then each other, then at me again. One said "Hmm. Well..." However, there were 15 minutes left. No oral boards examiner worth his or her salt will let an examinee finish early. So they grilled me about the genetics of HD (which thankfully I had randomly studied a few days earlier) and then basically turned it into a free-for-all. They grilled me about whatever the heck they wanted to. But I passed and never did really give them a differential diagnosis for that patient.

Thanks, Mrs. X.