HY lecture notes:
The main value of this lecture is the emphasis on the importance psych screening on the FM shelf.
“Suicidal ideation” on the FM shelf is pretty much always the answer if it’s listed. Always address psych first for FM, even if the vignette is clearly discussing a salient diagnosis like hypothyroidism, where your initial gut is to jump on “check serum TSH.” Once again, if “suicidal ideation” is listed, go with it.
Any patient over the age of 50 who presents with what appears to be cognitive decline, always check for depression first.
Pseudodementia is depression presenting as cognitive decline (but the patient doesn’t actually have true dementia). The patient will not try on the mini mental state exam (MMSE), whereas a patient with true dementia will try. In other words, a patient with pseudodementia may perform poorly on the MMSE because of apathy, and this is evidenced by notably poor performance on the reverse serial 7s component, which requires greater concentration. They may also say that an, e.g., 58M draws a clock very slowly, but once prompted, is able to finish it quickly.
Another HY point is if they say the patient complains about his or her own memory loss. In this case, the answer is normal aging, not dementia. Patients with true dementia don’t complain about their cognitive decline. If they say anything about an, e.g., 72F who is concerned because she says she walks into rooms and can’t remember why she went in there, the answer is normal aging. Once again, patients with true dementia often try to cover it up, rather than complain about it.
So if you get a vignette where a patient over age 50 has cognitive decline + appears quiet and is not making much eye contact, think pseudodementia. Answer = “check for suicidal ideation.” Tx for depression = SSRI and/or CBT.
2CK-level hypothyroidism presents much different from Step 1. On Step 1, the presentation is classically dry hair, brittle skin, constipation, cold intolerance, weight gain, etc. This is too easy for FM/psych shelf + 2CK. Important presentation descriptors are:
- Low mood (dysthymia).
- Mood will improve with administration of thyroid hormone.
- Proximal muscle weakness.
- Difficulty getting up from chair unassisted +/ increased serum creatine kinase (CK).
- Increased serum cholesterol.
- They might say total cholesterol of 300 mg/dL.
- Increased hepatic transaminases.
- You might see AST is elevated and say “wtf?” But this is frequent in thyroid dysfunction.
- Bradycardia (HR of 55-60).
- Not abnormal per se, as plenty of healthy people can have have bradycardia, but I’ve observed that this is nevertheless slipped into hypothyroidism Qs as a frequent detail.
For hypothyroidism Qs, although “check serum TSH” is the correct answer for initial screening, once again, if “check for suicidal ideation” is listed, this will still be the answer ahead of TSH. You will always do a simple psych screen ahead of ordering investigations.
Hashimoto = low T3, low T4, high TSH, decreased radioiodine uptake.
Subclinical hypothyroidism = normal T3, normal T4, high TSH, normal or reduced uptake.
Euthyroid sick syndrome = decreased T3, high reverse-T3, normal TSH, normal T4.
Graves = high T3, high T4, low TSH, high diffuse uptake.
Toxic multinodular goiter = high T3, high T4, low TSH, high multifocal uptake.
Toxic adenoma = high T3, high T4, low TSH, high uptake isolated to one nodule.
Factitious thyrotoxicosis with levothyroxine (T4) = high T3, high T4, low TSH, low uptake.
Factitious thyrotoxicosis with triiodothyronine (T3) = high T3, low T4, low TSH, low uptake. (T4 is converted to T3 peripherally, but not the other way around).
Subacute thyroiditis (subacute granulomatous thyroiditis; DeQuervain) = can be hyper- or hypo-, but the key is that uptake is decreased always no matter what –> so if the patient is hyper-, choose high T3, high T4, low TSH, decreased uptake.
