NBME MBB Shelf Pathologies Latest Update

NBME MBB Shelf Pathologies Latest Update

• Questions and 100% Verified Correct

Answers Actual Exam Guaranteed A+

Acute intermittent porphyria - CORRECT ANSWER: A condition of heme synthesis.

Affected enzyme is porphobilinogen deaminase, accumulated substrate is porphobilinogen, delta-ALA, uroporphyrin (urine). Symptoms (5 P's): painful abdomen, port wine-colored urine, polyneuropathy, psychological disturbances, precipitated by drugs

Treatment: glucose and heme, which inhibit ALA synthase.

BRS BS: abdominal cramps, diarrhea and vomiting, seizures, cardiac arrhythmias,

flushing, purple/red discoloration of urine due to elevated porphobilinogen. Psychiatric symptoms include paranoid delusions and hallucinations as well as depression and anxiety.

Addison Disease - CORRECT ANSWER: Chronic primary adrenal insufficiency due to

adrenal atrophy or destruction by disease (e.g. autoimmune, TB, metastasis).Deficiency of aldosterone and cortisol, causing hypotension (hyponatremic volume contraction), hyperkalemia, acidosis, skin hyperpigmentation (due to MSH, a by-product of increased ACTH production from POMC). Characterized by Adrenal Atrophy and Absence of hormone production; involves All 3 cortical divisions (spares medulla).Associated psychiatric symptoms.BRS BS: hypotension, pain, fainting, hypoglycemia, diarrhea, vomiting, depression, psychosis, confusion

Alexia and agraphia - CORRECT ANSWER: part due to disrupted pathways in angular

gyrus pathways connect visual projection area with auditory association areas

Alexia without agraphia - CORRECT ANSWER: lesion of posterior cerebral artery;

patient can write but not read; language cut off from visual - splenum of corpus callosum lesion

• / 2

Alzheimer's Disease - CORRECT ANSWER: Most common Dementia. Nucleus basalis

of Meynert undergoes degeneration --> loss of ACh in cortex leading to neural atrophy in cortex and hippocampus Cholinesterase inhibitors (galantamine) are treatment - increase available ACh (caution with bradycardia and ulcers patients); cause GI side effects (possible anorexia, insomnia) Glutamate-mediated excitotoxicity also implicated in pathogenesis

• memantine (trade name Namenda) is an NMDA antagonist

Down Syndrome predisposes for Alzheimers

Familial form (10%) associated with:

- Early onset: APP (c21), presenilin-1 (c14), presenilin-2 (c1)

- Late onset: ApoE4 (c19)

ApoE2 is protective

Angelman's syndrome - CORRECT ANSWER: Maternal allele is not expressed. Mental

retardation, seizures, ataxia, inappropriate laughter. Genetic component on component 15.

Anorexia nervosa - CORRECT ANSWER: Excessive dieting +/- purging; intense fear of gaining weight, body image distortion, increase in exercise, leading to body weight less than 85% of ideal body weight (17.5 BMI)

• associated with low bone density

Severe weight loss, metatarsal stress fractures, amenorrhea, anemia, electrolyte disturbances. Commonly coexists with depression *increased chance of osteoporosis

Arnold-Chiari malformation II - CORRECT ANSWER: Significant cerebellar tonsillar and vermian herniation through foramen magnum with aqueductal stenosis and hydrocephalus. Often present with thoraco-lumbar myelomeningocele and paralysis below the defect.Arnold-Chiari malformation with or without myelomeningocele is characterized by a cerebellomedullary malformation that may not develop until adolescence or adult life.

• / 2