STEP 2 Concepts

An 82-year-old woman is brought to the physician by her granddaughter because of a 6-week history of increasing forgetfulness. She is a retired schoolteacher and lives independently. Her granddaughter is concerned because on several occasions she has left the stove on when she went to bed, During conversations with her granddaughter, she has difficulty remembering past events and seems unconcerned about her memory lapses. The patient describes trouble sleeping through the night and has had a decreased appetite resulting in a 4.5-kg (10-lb) weight loss over the past month. She has a history of similar sympton,s 2 and 5 years ago that were successfully treated with medication. She appears unkempt and has poor personal hygiene. Her temperature is 37°C (98.6°F), blood pressure is 110/70 mm 'Hg, and pulse is 80/niin and regular. Mental status examination sho~s psychomotor retardation, a flat affect, impaired ability to recall past events, and trouble repeating three numbers in sequence. She is unable to recall the names of recent presidents. Her serum urea nitrogen concentration is 25 mg/dl, and serum creatinine concentration is 1. 7 n,g/dl.

This case describes an elderly woman exhibiting symptoms consistent with major depressive disorder, characterized by cognitive impairment (memory lapses), changes in appetite, sleep disturbances, and psychomotor retardation. The patient's history of similar symptoms treated with medication suggests recurrent episodes of depression.

32-year-old woman with infertility, irregular 35–50-day menstrual cycles, obesity, and acne. TSH, LH, FSH, testosterone, and DHEAS are normal. What is the most likely diagnosis?

Diagnosis: Polycystic ovary syndrome (PCOS)

Key clues

• Infertility from chronic anovulation

• Irregular, long cycles: every 35–50 days

• Obesity

• Acne = clinical hyperandrogenism

• Normal TSH, LH, FSH, testosterone, and DHEAS do not exclude PCOS

Flashcard takeaway:
Reproductive-age woman with oligomenorrhea + signs of androgen excess + infertility → think PCOS, even when serum androgen levels are normal.

24-year-old man with sudden, worsening right-sided chest pain and dyspnea. Vital signs are normal. Chest x-ray is below. What is the next step in management?

Patient has a right-sided pneumothorax

Answer:

Chest tube placement (tube thoracostomy) because he has a symptomatic, likely large spontaneous pneumothorax.

Key point:

• Stable but large/symptomatic pneumothorax → chest tube

• Small and minimally symptomatic → observation with oxygen

• Tension pneumothorax with hypotension or instability → immediate needle decompression, then chest tube

52-year-old man with obesity, polyuria, nocturia, weight loss, and a random glucose of 280 mg/dL. He has newly diagnosed type 2 diabetes mellitus. BP 160/85. Which serum concentration is most likely increased?

A. Glucagon
B. Insulin
C. Ketones

Answer:
Insulin concentration — early type 2 diabetes causes insulin resistance, so pancreatic β cells compensate by producing more insulin.

Key point:

• Early type 2 DM: ↑ insulin and ↑ C-peptide

• Later type 2 DM: β-cell failure can cause insulin levels to decrease

• Weight loss occurs because glucose cannot be used effectively, leading to breakdown of fat and muscle.

67-year-old man with sudden vertigo, nausea, nystagmus, right-sided Horner syndrome, right palate weakness, decreased pain sensation on the right face and left body, and right-sided limb ataxia. Which artery is occluded?

Answer:
Right posterior inferior cerebellar artery (PICA) → lateral medullary (Wallenberg) syndrome

Key clues:

• Vertigo/nystagmus → vestibular nuclei

• Ipsilateral Horner syndrome

• Ipsilateral facial pain-temperature loss

• Contralateral body pain-temperature loss

• Dysphagia/palate weakness → nucleus ambiguus

• Ipsilateral ataxia

Memory tip: PICA = “Don’t PICA horse that can’t eat” → dysphagia and hoarseness from nucleus ambiguus injury.