A Crunch Time Cram
The following pages contain high yield information designed for review in the days just
preceding the Step 1 examination.
MOST COMMON
Often on the USMLE exam, the student finds two responses that could potentially answer a
question. The NBME is testing the student to identify the more common of the two responses;
for example, the more common cause, site, or type. Below is a high yield summary of the most
common characteristics of the various disorders listed in this text.
Nervous System
Most Common…
Aneurysm of Circle of Anterior communicating artery; bitemporal hemianopsia
Willis
Blindness Diabetic retinopathy
Blindness—preventable Chlamydia trachomatis
Bacterial meningitis— Streptococcus pneumoniae
elderly
Bacterial meningitis— E. coli
newborns
Bacterial meningitis— Haemophilus influenza type b
toddlers
Bacterial meningitis— Neisseria meningitidis
young adults
Cancer of the brain—child Medulloblastoma (cerebellum)
Cancer of the brain—adult Astrocytoma (including glioblastoma multiforme), then
metastasis, meningioma, schwannoma
Dementia 1. Alzheimer's
2. Multi-infarct dementia
Demyelinating disease Multiple sclerosis
Location of adult brain Above tentorium
tumors
Location of childhood Below tentorium (Mnemonic: Children are short, they cannot reach
brain tumors above the tentorium)
Mental retardation 1. Down syndrome or Fragile X
2. Fetal alcohol syndrome
Motor neuron disease Amyotrophic lateral sclerosis (ALS)
Viral encephalitis HSV
USMLE Step 1 High Yield Summary
, Cardiovascular System
Most Common…
Acute mitral insufficiency—children Kawasaki disease
Aneurysm Abdominal aorta
AV fistula Penetrating knife wound
Cancer of the heart—adults Metastases
Cancer of the heart—primary—adults Myxoma “Ball Valve”
Cancer of the heart—primary—kids Rhabdomyoma
Cardiomyopathy Dilated (congestive) cardiomyopathy
Cause of acute endocarditis Staphylococcus aureus
Cause of subacute endocarditis Streptococcus viridans
Congenital cardiac anomaly Ventricular septal defect (membranous >
muscular)
Congenital early cyanosis Tetralogy of Fallot
Coronary artery thrombosis Left anterior descending
Death in HTN 1. Acute mitral insufficiency
2. Lenticulostriate stroke
3. Renal failure (benign nephrosclerosis)
Death in the United States Ischemic heart disease
Heart murmur Mitral valve prolapsed
Heart valve in bacterial endocarditis Mitral
Heart valve in bacterial endocarditis in IV drug Tricuspid
users
Heart valve involved in rheumatic fever Mitral > Aortic
Hypertension 1. Essential (95%)
2. Renal disease
Hypertension—children Renal disease; cystic disease, Wilms tumor
Hypertension—young women Oral contraceptives
Myocarditis Coxsackie B virus
Right heart failure Left heart failure
Secondary hypertension Renal disease
Sites of atherosclerosis Abdominal aorta > coronary > popliteal >
carotid
Vasculitis (of medium and small arteries) Temporal arteritis
Respiratory System
Most Common…
Cause of pneumonia in debilitated, Klebsiella
hospitalized patient
Cause of epiglottitis Haemophilus influenza type b
Cause of IV drug user Staphylococcus aureus
bacteremia/pneumonia
USMLE Step 1 High Yield Summary