Psych| OCD and Related Disorders

4.11 Antibody Review Rheumatology review for the USMLE Step 1 Exam. ANA Principles ANA (Anti-Nuclear Antibody): Non-specific antibody. Reacts against nuclear antigens, including proteins, DNA, RNA, and nucleic acid-protein complexes. Includes a group of antibodies such as anti-dsDNA, anti-histone, SSA/Ro, SSB/La, Scl-70, anti-aminoacyl-tRNA synthetase (Jo-1). Found in 20-30% of the general public without connective tissue disorder symptoms. ANA+ individuals may or may not have a rheumatologic disorder. Further workup is needed in ANA+ cases to determine the specific disorder. Antibodies by Disease Process Systemic Lupus Erythematosus (SLE) Anti-dsDNA antibody. Anti-Smith antibody. Drug-Induced Lupus Anti-histone antibody. Diffuse vs. Limited Scleroderma Diffuse: Anti-Scl-70 (anti-topoisomerase I). Limited: Anti-centromere (often called CREST syndrome, with CREST standing for centromere). Sjogren's Syndrome Anti-SSA (Ro). Anti-SSB (La), which usually occurs in the presence of SSA. SSA is considered the Sjogren-specific antibody, leading to the presence of SSB. Rheumatoid Arthritis (RA) Anti-CCP (Cyclic Citrullinated Peptide). RF (Rheumatoid Factor) is non-specific. Thanks for listening!

4.10 Gout and Pseudogout Rheumotology review for the USMLE Step 1 Exam. Gout Caused by uric acid crystal deposition due to purine metabolism. Triggers inflammation when crystals precipitate in cooler joint fluid. Presents with severe, red, and swollen monoarticular joints, often in the big toe. Diagnosis through synovial fluid analysis. Acute treatment: colchicine, NSAIDs, and glucocorticoids. Preventive treatment: allopurinol, febuxostat, probenecid, and lifestyle changes. Pseudogout Resulting from calcium pyrophosphate crystal deposition, often due to ATP breakdown. Manifests with painful, swollen joints, typically affecting multiple upper extremity joints, especially the knee. Diagnosis through synovial fluid analysis. Acute treatment resembles gout management. No direct preventive treatment to lower calcium pyrophosphate levels. Thanks for listening!

4.09 Rheumatologic Emergencies Rheumatology review for USMLE Step 1 Exam Giant Cell Arteritis (GCA) A large vessel vasculitis, mainly in older individuals. Symptoms: headache, jaw claudication, vision loss. Ischemia from granulomas in large vessels causes vision loss. Immediate high-dose corticosteroids are crucial. Scleroderma Renal Crisis A complication of scleroderma. Symptoms: finger edema, skin tightening, sudden hypertension, rising creatinine. Renal artery fibrosis leads to high blood pressure. Treat with IV ACE inhibitor, not steroids. Acute Transverse Myelitis in SLE Inflammation of the spinal cord in lupus. Symptoms: bilateral numbness, tingling, weakness. Treat with corticosteroids. Catastrophic Antiphospholipid Syndrome (CAPS) A rare, life-threatening form of APS. Symptoms: unexplained miscarriages, unexplained clots, multiorgan failure. Treat with anticoagulation followed by immune suppression

1.06 Systolic Heart Murmurs Cardiovascular system review for the USMLE STEP 1 Exam Heart murmurs are caused by turbulent blood flow in the heart There are 4 different types of systolic murmurs: ventricular septal defect (VSD), patent ductus arteriosus (PDA), aortic stenosis, and mitral or tricuspid regurgitation PDA produces a constant, machine-like murmur VSD produces a harsh holosystolic murmur Aortic stenosis produces a crescendo-decrescendo systolic ejection murmur Mitral and tricuspid regurgitation produce a holosystolic high pitched "blowing" murmur Mitral valve prolapse produces a mid-systolic click followed by a late systolic murmur Aortic regurgitation produces a decrescendo diastolic murmur Mitral stenosis produces a rumbling diastolic murmur  

5.13 OCD and Related Disorders Psych review for the USMLE Step 1 Exam Obsessive Compulsive Disorder (OCD): Unwanted thoughts (obsessions) and repetitive behaviors (compulsions). Treat with CBT + SSRIs/SNRIs. Tic Disorders: Tourette Syndrome involves multiple motor and at least one vocal tic. Treat with Habit Reversal Therapy. Body Dysmorphic Disorder: Preoccupation with minor flaws, treat with SSRIs and CBT. Trichotillomania: Hair pulling disorder, treat with Habit Reversal Training and sometimes SSRIs. PANDAS: Pediatric disorder after strep infection, sudden OCD-like symptoms. Treat with antibiotics, CBT, and SSRIs.

5.12 Anxiety Related Disorders Psychiatry review for the USMLE Step 1 Exam Anxiety is a normal response to threats or stressors in the environment Anxiety disorders occur when anxiety causes significant distress or impairment in functioning Generalized Anxiety Disorder (GAD) involves persistent and excessive worry about various aspects of daily life for at least 6 months, accompanied by physical symptoms Treatment for GAD typically involves a combination of cognitive-behavioral therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs) Panic Disorder is diagnosed in individuals who experience spontaneous panic attacks and fear future attacks Panic attacks are acute episodes of intense anxiety and physical symptoms Treatment for Panic Disorder involves CBT and SSRIs, with SSRIs being the first-line medication Agoraphobia is the fear of being in public places where escape may be difficult and often follows a traumatic event CBT and SSRIs are the recommended treatment for Agoraphobia Social Anxiety Disorder (Social Phobia) involves fear of scrutiny or embarrassment in social situations Public speaking can be a significant trigger for individuals with social anxiety disorder Beta blockers can be used to treat social anxiety disorder by reducing physical symptoms Treatment for social anxiety disorder usually involves CBT, SSRIs, or beta blockers.

5.11 Eating and Feeding Disorders Psychiatry Review for the USMLE Step 1 Exam Eating Disorders: Main disorders: bulimia nervosa, anorexia nervosa, and binge eating disorder. Bulimia and anorexia share anxiety and compensatory behaviors. Anorexia: low body weight, fear of gaining weight, treatment involves slow refeeding. Bulimia: normal weight, signs of forced vomiting, treated with CBT and SSRIs. Binge Eating Disorder: uncontrollable eating, negative emotions, SSRIs and CBT for treatment. Feeding Disorders: Occur in children, not related to body image. Common disorders: avoidant/restrictive food intake disorder, rumination disorder, and pica. Avoidant/Restrictive Food Intake Disorder: avoidance or restriction of food intake. Pica: eating non-nutritious substances, common in young children. Rumination Disorder: regurgitation without associated symptoms.

5.10 Mood Disorders (Depression and Bipolar) Psychiatry Review for the USMLE Step 1 exam Mood disorders are persistent disruptions in emotion, categorized into bipolar disorders and depressive disorders. Bipolar disorders are characterized by manic or hypomanic episodes, while depressive disorders feature periods of depression. Major Depressive Disorder (MDD) is characterized by feelings of sadness, guilt, worthlessness, and anhedonia lasting for at least two weeks. SIG E CAPS is an acronym used to remember the symptoms of depression: Sleep changes, Interest loss, Guilt, Energy loss, Concentration difficulties, Appetite changes, Psychomotor retardation, and Suicidal ideation. In MDD, at least 5 of the SIG E CAPS symptoms must persist for more than 2 weeks. Persistent Depressive Disorder (dysthymia) is a chronic, low-grade form of MDD that lasts for at least two years. Mania is a symptom common to all bipolar disorders, characterized by elevated or irritable mood and increased activity or energy. Mania lasting for at least 1 week is called a manic episode, while hypomania is a less severe form lasting longer than 4 days. The symptoms of mania can be remembered using the mnemonic DIG FAST: Distractibility, Irritable mood/insomnia, Grandiosity, Flight of ideas, Agitation/increased activity, Speedy thoughts/speech, and Thoughtlessness. Bipolar I involves manic episodes, and bipolar II involves hypomanic episodes and major depressive episodes. Bipolar I requires at least one manic episode, while bipolar II requires depressive episodes. Mood stabilizers such as lithium, valproate, carbamazepine, and lamotrigine are used to treat bipolar disorders. Litium is the best (notable exeptions however). Antidepressants are contraindicated for bipolar patients due to the risk of flipping into mania. The risk of suicide is high in bipolar patients, with 25-50% attempting suicide and 10-15% dying by suicide. Cyclothymia is a less common form of bipolar disorder characterized by cycling between hypomania and mild depression over many years.

5.09 Schizophrenia Psychiatry review for the USMLE Step 1 Exam Epidemiology: Slight male predilection (1.4:1 male to female ratio). Men present between 18-25, women between 28-35. Affects about 0.5% of the population. Symptoms: Positive symptoms: hallucinations, delusions, disorganized behavior and speech. Negative symptoms: flat affect, anhedonia, apathy, alogia, lack of interest in socialization. Cognitive symptoms: impairments in attention, executive function, working memory. Diagnosis: Criteria: two or more symptoms lasting over a month. Schizophreniform disorder if symptoms last less than 1 month. Pathophysiology: Excess dopamine in prefrontal cortical pathway (negative symptoms). Excess dopamine in mesolimbic pathway (positive symptoms). Other neurotransmitters may also play a role (especially serotonin excess). Treatments: Antipsychotics (D2 receptor antagonists). First-generation antipsychotics: haloperidol, chlorpromazine (more side effects). Second-generation antipsychotics (atypical antipsychotics): aripiprazole, olanzapine, quetiapine, risperidone (lower extrapyramidal side effects, higher metabolic side effects). Outcomes: Rule of thirds: one-third full recovery, one-third improved with mild symptoms, one-third require high-level care.  

5.08 Cluster C Personality Disorders Psychiatry review for the USMLE Step 1 Exam Introduction: Cluster C personality disorders = anxious/worried. Disorders: avoidant, obsessive-compulsive, dependent. Distinguish from normal traits. Avoidant Personality Disorder: Inhibited, introverted, anxious. Fear of rejection, low self-esteem. Characteristics: avoidance, preoccupation with criticism/rejection, social ineptness. Treatment: Anti-anxiety drugs may help temporarily. Obsessive-Compulsive Personality Disorder: Perfectionism, inflexibility, diligence. Not OCD; need for control, not obsessions/compulsions. Characteristics: details, work focus, rigidity. Example: Mark, unemployed with attention to detail. Dependent Personality Disorder: Excessive reliance on others for support/decisions. Linked to early medical/psychiatric conditions. Characteristics: decision-making, fear of disapproval, reliance. Example: Bob, farm laborer dependent on mother. Conclusion: Cluster C = anxiety-driven. Understand characteristics, not specific diagnoses. Examples show impact on lives.