A 28-year-old male veteran presents to an outpatient clinic reporting a 5-month history of… — USMLE Step 2 CK

A 28-year-old male veteran presents to an outpatient clinic reporting a 5-month history of severe sleep disturbances, hypervigilance, and intrusive memories of a combat engagement. He avoids crowded places and frequently scans his environment for threats. During the interview, he appears visibly tense. He also reports a recent onset of profound fatigue, constipation, and feeling cold all the time over the past 4 weeks.

His psychiatric history is significant for a severe episode of grandiosity, pressured speech, and lack of sleep that required inpatient hospitalization at age 22. He is currently taking isocarboxazid, a monoamine oxidase inhibitor (MAOI), prescribed two years ago for treatment-resistant depression, but he reports it is no longer effective and finds the dietary restrictions burdensome.

Vital signs are within normal limits. Laboratory testing reveals:
- Thyroid-stimulating hormone (TSH): $0.1 \text{ \mu U/mL}$ (Normal: $0.5 - 5.0 \text{ \mu U/mL}$ )
- Free thyroxine (T4): $0.6 \text{ ng/dL}$ (Normal: $0.9 - 1.7 \text{ ng/dL}$ )

The physician decides to restructure his psychiatric and medical management.

Which of the following are the most appropriate next steps in management? (Choose two correct answers)

Initiate prolonged exposure therapyAnswer
Order a magnetic resonance imaging (MRI) scan of the brain to evaluate the pituitary glandAnswer
C
Discontinue isocarboxazid and begin escitalopram the following day
D
Discontinue isocarboxazid, implement a two-week washout phase, and then begin sertraline monotherapy
E
Conclude a diagnosis of primary hypothyroidism and prescribe levothyroxine

Answer

The correct interventions are to initiate prolonged exposure therapy and order a magnetic resonance imaging (MRI) scan of the brain.

The appropriate management for this patient involves initiating prolonged exposure therapy (a first-line, evidence-based trauma-focused psychotherapy for PTSD) and ordering a brain MRI to evaluate his central hypothyroidism. Central hypothyroidism is confirmed by the presence of a low free T4 coupled with an inappropriately low TSH, which requires neuroimaging to rule out a structural lesion in the pituitary or hypothalamus.

Step-by-Step Solution

Diagnose the psychiatric conditions based on the clinical presentation.

The patient has Post-Traumatic Stress Disorder (PTSD) due to hypervigilance, flashbacks, and avoidance lasting >1 month. He also has a history of Bipolar I Disorder, indicated by a prior hospitalization for mania.

Accurate psychiatric diagnosis dictates the selection of safe and effective psychotherapeutic and pharmacological interventions.

Determine the appropriate treatment for the trauma-related symptoms.

Trauma-focused psychotherapy, such as prolonged exposure therapy, is the first-line treatment for PTSD and is safe to initiate concurrently.

First-line non-pharmacological therapies should be prioritized, especially given the patient's complex medication history and bipolar status.

Analyze the laboratory results in the context of the medical symptoms.

The patient's fatigue, cold intolerance, and constipation, combined with low free T4 and an inappropriately low TSH, indicate central (secondary) hypothyroidism.

Primary hypothyroidism features an elevated TSH. The lack of an elevated TSH response points to a pituitary or hypothalamic failure.

Determine the next medical step for central hypothyroidism.

An MRI of the brain/pituitary is required to evaluate for a central structural cause, such as a pituitary macroadenoma.

Central hypothyroidism warrants neuroimaging before initiating hormone replacement to rule out compressive lesions.

Evaluate the safety of pharmacological transitions.

Discontinuing the MAOI requires a 14-day washout before starting any serotonergic drug. Furthermore, SSRI monotherapy must be avoided due to his history of Bipolar I Disorder.

MAOI to SSRI crossover without washout causes serotonin syndrome. SSRI monotherapy in bipolar disorder precipitates manic switches.

Key Concept

Management of PTSD complicated by Bipolar I Disorder, psychopharmacological washout periods, and interpretation of central hypothyroidism.

Estimated Time:2m 30s

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic