USMLE ( United States Medical Licensing Examination) Step 2 CK Study Guide

Pediatrics GI ● Inflammatory diarrhea (blood in stool and afebrile) ○ Shigella, Campylobacter, Salmonella, Shiga toxin E.Coli ■ E.coli usually self-resolve w/in 1 week unless complicated by HUS 1-2 wks later (prevent by avoiding Abx) Neuro ● Closed spinal dysraphism (spina bifida occulta) ○ Failed fusion of vertebral arches ○ Symptoms = cutaneous (lumbosacral hemangioma), neurologic deficits due to tethered cord syndrome ■ LMN signs (weakness, hypotonia, hyporeflexia, sensory loss) Medicine Neuro ● Cavernous sinus thrombosis ○ Can results from uncontrolled skin infection (face) because facial/ophthalmic venous system is valveless ○ Symptoms → HA, periorbital edema, CN 3, 4, 5, 6 defects ● Myasthenia gravis ○ Fatigable weakness that involves ocular and/or bulbar (dysphagia) muscles that’s worse at the end of the day (resolves w/ rest) ■ NOTE Fatigability throughout the day is more consistent w/ myasthenia gravis than MS (MS symptoms relapse and remit slowly over days to weeks) ○ Dx – Acetylcholine receptor Ab ■ (+) imaging (Chest CT/MRI) → thymic abnormalities are seen in most pts w/ AChR Abs (thymic hyperplasia, thymoma) ● Pronator drift ○ Sensitive/specific sign for UMN or pyramidal/corticospinal tract disease ○ Only proprioception used to maintain arm position Pulm/Critical Care ● Pulmonary contusion ○ CXR usually negative (may take hours for clinically significant alveolar edema to accumulate) ○ Chest CT → patchy, irregular alveolar infiltrates; non-lobular (not restricted by anatomic landmarks) ○ Symptoms – tachypnea, hypoxemia, decreased breath sounds CV ● Right ventricular MI ○ Epigastric pain, nausea ○ Obtain right-sided precordial ECG ○ Do not give nitroglycerin! ■ Reduced RV preload