Neuroleptic malignant syndrome US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Neuroleptic malignant syndrome. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Neuroleptic malignant syndrome US Medical PG Question 1: A 16-year-old girl is brought to the emergency department by her friends who say that she took a whole bottle of her mom’s medication. They do not know which medication it was she ingested. The patient is slipping in and out of consciousness and is unable to offer any history. Her temperature is 39.6°C (103.2°F), the heart rate is 135/min, the blood pressure is 178/98 mm Hg, and the respiratory rate is 16/min. On physical examination, there is significant muscle rigidity without tremor or clonus. Which of the following is the best course of treatment for this patient?
- A. Cyproheptadine
- B. Dantrolene (Correct Answer)
- C. Flumazenil
- D. Fenoldopam
- E. Naloxone
Neuroleptic malignant syndrome Explanation: ***Dantrolene***
- The patient's presentation with **hyperthermia**, **tachycardia**, **hypertension**, and **severe muscle rigidity without tremor or clonus** is highly suggestive of **neuroleptic malignant syndrome (NMS)** or **malignant hyperthermia**.
- **Dantrolene** is a direct-acting **skeletal muscle relaxant** that reduces calcium release from the sarcoplasmic reticulum, effectively treating the muscle rigidity and hyperthermia in these conditions.
*Cyproheptadine*
- **Cyproheptadine** is an **antihistamine with serotonin antagonist properties** used to treat **serotonin syndrome**, which typically presents with **clonus** and **hyperreflexia**, not the rigidity seen here.
- While both NMS and serotonin syndrome involve hyperthermia, the distinct absence of clonus and presence of severe rigidity points away from serotonin syndrome.
*Flumazenil*
- **Flumazenil** is a **benzodiazepine receptor antagonist** used to reverse **benzodiazepine overdose**.
- Benzodiazepine overdose typically causes **CNS depression** (hypotension, bradycardia, respiratory depression), which is opposite to the patient's hyperdynamic state.
*Fenoldopam*
- **Fenoldopam** is a **D1 dopamine receptor agonist** used intravenously to treat **severe hypertension** and **hypertensive emergencies**.
- Although the patient has hypertension, fenoldopam would not address the underlying pathology of hyperthermia and muscle rigidity, which are the primary life-threatening issues.
*Naloxone*
- **Naloxone** is a **mu-opioid receptor antagonist** used to reverse **opioid overdose**.
- Opioid overdose typically causes **respiratory depression**, **miosis**, and **CNS depression**, which are not consistent with this patient's presentation.
Neuroleptic malignant syndrome US Medical PG Question 2: A 31-year-old man is brought to the emergency department because of fever and increasing confusion for the past day. He has bipolar disorder with psychotic features and hypothyroidism. Current medications are lithium, haloperidol, and levothyroxine. He drinks one beer with dinner every night. His speech is confused and he is oriented to person only. His temperature is 40°C (104°F), pulse is 124/min, and blood pressure is 160/110 mm Hg. He appears acutely ill. Examination shows diaphoresis and muscle rigidity. Deep tendon reflexes are 1+ bilaterally. There is minor rigidity of the neck with full range of motion. His lungs are clear to auscultation. The abdomen is soft and nontender. His leukocyte count is 15,100/mm3 and serum creatine kinase activity is 1100 U/L. Which of the following is the most likely diagnosis?
- A. Delirium tremens
- B. Neuroleptic malignant syndrome (Correct Answer)
- C. Bacterial meningitis
- D. Herpes simplex encephalitis
- E. Lithium toxicity
Neuroleptic malignant syndrome Explanation: ***Neuroleptic malignant syndrome***
- The patient presents with **fever (40°C)**, **muscle rigidity**, **altered mental status (confusion)**, **autonomic instability (tachycardia, hypertension, diaphoresis)**, and **elevated creatine kinase**, all classic features of **Neuroleptic Malignant Syndrome (NMS)**.
- The use of **haloperidol**, a high-potency antipsychotic, is a significant risk factor for NMS.
*Delirium tremens*
- While delirium tremens can cause altered mental status, autonomic instability, and fever, it is typically preceded by a history of **heavy chronic alcohol intake** followed by acute withdrawal, which is not indicated by "one beer with dinner every night."
- **Muscle rigidity** and **marked elevation of creatine kinase** are not typical features of delirium tremens.
*Bacterial meningitis*
- Although bacterial meningitis presents with fever and altered mental status, it would typically involve **nuchal rigidity** that limits range of motion, which is not fully present here, and **CSF findings** (e.g., pleocytosis, low glucose) would be diagnostic.
- **Profound muscle rigidity** and **markedly elevated creatine kinase** are not characteristic features of bacterial meningitis.
*Herpes simplex encephalitis*
- This condition presents with fever, altered mental status, and often **focal neurological deficits** or **seizures**, which are not described.
- Diagnosis relies on **characteristic MRI findings** and **CSF PCR for HSV DNA**, and it would not typically cause diffuse **muscle rigidity** or **elevated creatine kinase**.
*Lithium toxicity*
- **Lithium toxicity** typically presents with neurological symptoms like **tremors**, **ataxia**, **nystagmus**, and altered mental status, but it is less commonly associated with **severe muscle rigidity**, **very high fever (40°C)**, or **markedly elevated creatine kinase** unless complicated by severe dehydration or NMS-like features.
- A **high lithium level** would be expected, which is not mentioned as present.
Neuroleptic malignant syndrome US Medical PG Question 3: A 26-year-old man is brought to the hospital by his wife who complains that her husband has been behaving oddly for the past few hours. The patient’s wife says that she has known him for only 4 months. The wife is unable to give any past medical history. The patient’s speech is difficult to follow, and he seems very distracted. After 15 minutes, he becomes agitated and starts to bang his head on a nearby pillar. He is admitted to the psychiatric ward and is given an emergency medication, after which he calms down. In the next 2 days, he continues to become agitated at times and required 2 more doses of the same drug. On the 4th day of admission, he appears very weak, confused, and does not respond to questions appropriately. His vital signs include: temperature 40.0°C (104.0°F), blood pressure 160/95 mm Hg, and pulse 114/min. On physical examination, he is profusely diaphoretic. He is unable to stand upright or even get up from his bed. Which of the following is the mechanism of action of the drug which most likely caused this patient’s current condition?
- A. Skeletal muscle relaxation
- B. Agonistic effect on dopamine receptors
- C. Serotonin reuptake inhibition
- D. Histamine H2 receptor blocking
- E. Dopamine receptor blocking (Correct Answer)
Neuroleptic malignant syndrome Explanation: ***Dopamine receptor blocking***
- The patient's presentation with **fever, altered mental status, muscle rigidity**, and **autonomic instability** (tachycardia, hypertension, diaphoresis) after receiving antipsychotic medication strongly suggests **neuroleptic malignant syndrome (NMS)**.
- NMS is caused by a severe decrease in **dopaminergic activity**, primarily due to the blockade of **D2 dopamine receptors** in the basal ganglia and hypothalamus by antipsychotics.
- The classic tetrad of NMS includes: **hyperthermia, muscle rigidity, altered mental status**, and **autonomic instability**.
*Skeletal muscle relaxation*
- While agitation might be treated with benzodiazepines, which cause muscle relaxation, this mechanism does not explain the **severe rigidity, hyperthermia**, and **autonomic dysfunction** seen in the patient.
- **Muscle rigidity** (lead-pipe rigidity) is a hallmark of the patient's current condition, contradicting the idea of muscle relaxation.
*Agonistic effect on dopamine receptors*
- An agonistic effect on dopamine receptors would typically lead to symptoms similar to **psychosis** or **mania**, not the severe rigidity and hypodopaminergic state observed in NMS.
- This mechanism would counteract the effects of antipsychotics and would not cause NMS.
*Serotonin reuptake inhibition*
- This is the mechanism of action for **SSRIs**, and an excess of serotonin can lead to **serotonin syndrome**, which shares some features with NMS but typically includes **hyperreflexia** and **myoclonus**, rather than lead-pipe rigidity.
- The context of treating acute psychosis with an emergency medication points more towards an antipsychotic, not an antidepressant.
*Histamine H2 receptor blocking*
- **Histamine H2 receptor blockers** are used to treat conditions like **acid reflux** and **peptic ulcers**; they have no direct neurological effects that would cause NMS.
- This mechanism is entirely irrelevant to the patient's psychiatric symptoms and subsequent severe adverse reaction.
Neuroleptic malignant syndrome US Medical PG Question 4: A 61-year-old man with a history of type 1 diabetes mellitus and depression is brought to the emergency department because of increasing confusion and fever over the past 14 hours. Four days ago, he was prescribed metoclopramide by his physician for the treatment of diabetic gastroparesis. His other medications include insulin and paroxetine. His temperature is 39.9°C (103.8°F), pulse is 118/min, and blood pressure is 165/95 mm Hg. Physical examination shows profuse diaphoresis and flushed skin. There is generalized muscle rigidity and decreased deep tendon reflexes. His serum creatine kinase is 1250 U/L. Which of the following drugs is most likely to also cause this patient's current condition?
- A. Fluphenazine (Correct Answer)
- B. Tranylcypromine
- C. Desflurane
- D. Methamphetamine
- E. Nortriptyline
Neuroleptic malignant syndrome Explanation: **Fluphenazine**
- The patient's symptoms (fever, confusion, muscle rigidity, elevated CK, autonomic instability like tachycardia and hypertension) after starting metoclopramide are highly suggestive of **neuroleptic malignant syndrome (NMS)**. Metoclopramide is a **D2 receptor antagonist** that can precipitate NMS. Fluphenazine is a **typical antipsychotic** that also blocks D2 receptors and is a classic cause of NMS.
- The combination of **D2 receptor blockade** (by metoclopramide) and another potent D2 blocker like fluphenazine would significantly increase the risk of NMS.
*Tranylcypromine*
- This drug is a **monoamine oxidase inhibitor (MAOI)**. While it can cause **serotonin syndrome** when combined with serotonergic drugs like paroxetine, the clinical picture of NMS (marked rigidity, very high fever, elevated CK) is distinct from typical serotonin syndrome.
- Serotonin syndrome typically involves **hyperreflexia** and **clonus**, whereas this patient presents with **decreased deep tendon reflexes** and generalized **muscle rigidity**, key features of NMS.
*Desflurane*
- Desflurane is an **inhaled anesthetic** that can trigger **malignant hyperthermia** in susceptible individuals. Malignant hyperthermia shares some features with NMS (hyperthermia, muscle rigidity) but is specifically triggered by inhaled anesthetics and succinylcholine, not D2 antagonists.
- Malignant hyperthermia presents acutely during or immediately after anesthesia exposure, which is not consistent with the patient's presentation following metoclopramide initiation.
*Methamphetamine*
- Methamphetamine is a **stimulant** that can cause hyperthermia, tachycardia, and agitation. However, it does not typically cause the profound **muscle rigidity** and significantly elevated **creatine kinase** characteristic of NMS.
- The mechanism of action for methamphetamine is primarily related to increased release of dopamine, norepinephrine, and serotonin, not D2 receptor blockade leading to NMS.
*Nortriptyline*
- Nortriptyline is a **tricyclic antidepressant (TCA)**. While TCAs can have anticholinergic effects and cause some autonomic instability, they are not typically associated with NMS or malignant hyperthermia.
- Long-term use of TCAs can occasionally contribute to **serotonin syndrome** when combined with other serotonergic agents, but NMS is not a direct result.
Neuroleptic malignant syndrome US Medical PG Question 5: A 16-year-old college student presents to the emergency department with a 3-day history of fever, muscle rigidity, and confusion. He was started on a new medication for schizophrenia 2 months ago. There is no history of sore throat, burning micturition, or loose motions. At the hospital, his temperature is 38.6°C (101.5°F); the blood pressure is 108/62 mm Hg; the pulse is 120/min, and the respiratory rate is 16/min. His urine is cola-colored. On physical examination, he is sweating profusely. Treatment is started with antipyretics and intravenous hydration. Which of the following is most likely responsible for this patient's condition?
- A. Diazepam
- B. Phenytoin
- C. Levodopa
- D. Amantadine
- E. Chlorpromazine (Correct Answer)
Neuroleptic malignant syndrome Explanation: ***Chlorpromazine***
- The patient's symptoms of **fever**, **muscle rigidity**, and **confusion**, combined with a history of starting an antipsychotic medication (**Chlorpromazine**), are highly indicative of **neuroleptic malignant syndrome (NMS)**.
- **Chlorpromazine** is a typical antipsychotic known to block dopamine receptors, which can lead to NMS. The **cola-colored urine** suggests **rhabdomyolysis**, a common complication of severe muscle rigidity in NMS.
*Diazepam*
- **Diazepam** is a benzodiazepine used to treat anxiety, seizures, and muscle spasms, and does not typically cause NMS.
- Its mechanism of action involves enhancing GABAergic neurotransmission, which is distinct from the dopaminergic blockade associated with NMS.
*Phenytoin*
- **Phenytoin** is an anticonvulsant medication that can cause a variety of side effects, but NMS is not one of them.
- Common side effects include **gingival hyperplasia**, **ataxia**, and **nystagmus**.
*Levodopa*
- **Levodopa** is primarily used to treat Parkinson's disease by increasing dopamine levels in the brain.
- While abrupt withdrawal of **Levodopa** can sometimes precipitate NMS-like symptoms in Parkinson's patients due to inadequate dopamine, starting it does not cause NMS, and it is not typically used for schizophrenia.
*Amantadine*
- **Amantadine** is an antiviral drug also used to treat Parkinson's disease; it is not an antipsychotic.
- It primarily acts as a dopamine agonist and NMDA receptor antagonist, and its use is not associated with causing NMS.
Neuroleptic malignant syndrome US Medical PG Question 6: A 22-year-old man presents to the emergency department with a 2-day history of fever and altered mentation. He reports fever without chills and rigors and denies sore throat, abdominal pain, headache, loose stool, burning micturition, or seizures. He has a history of tics and is currently on a low dose of haloperidol. At the hospital, his temperature is 39.6°C (103.2°F); the blood pressure is 126/66 mm Hg, and the pulse is 116/min. He is profusely sweating and generalized rigidity is present. He is confused and disoriented. He is able to move all his limbs. Normal deep tendon reflexes are present with bilateral downgoing plantar responses. A brain MRI is unremarkable. Urine toxicology is negative. The white blood cell count is 14,700/mm3. Creatine kinase is 5600 U/L. Lumbar puncture is performed and cerebrospinal fluid (CSF) studies show:
CSF opening pressure 22 cm H20
CSF white blood cells 4 cells/mm3
CSF red blood cells 0 cells/mm3
CSF glucose 64 mg/dL
CSF protein 48 mg/dL
Serum glucose 96 mg/dL
What is the most likely diagnosis?
- A. Cerebral venous sinus thrombosis
- B. Acute disseminated encephalomyelitis
- C. Encephalitis
- D. Neuroleptic malignant syndrome (Correct Answer)
- E. Meningitis
Neuroleptic malignant syndrome Explanation: ***Neuroleptic malignant syndrome***
- The patient's presentation with **fever, altered mentation, muscle rigidity, profuse sweating, elevated creatine kinase**, and a history of **haloperidol** use is highly consistent with Neuroleptic Malignant Syndrome (NMS).
- **Haloperidol** is a dopamine antagonist, and its use is a well-known risk factor for NMS, which is characterized by a severe idiosyncratic reaction to neuroleptic medications.
*Cerebral venous sinus thrombosis*
- This condition typically presents with **severe headaches, focal neurological deficits, and seizures**, often seen on MRI or CT venography.
- The patient's normal MRI and generalized symptoms without focal deficits make this diagnosis less likely.
*Acute disseminated encephalomyelitis*
- ADEM is an **autoimmune demyelinating disease** often following an infection or vaccination, typically presenting with multifocal neurological deficits.
- The patient's presentation, particularly the muscle rigidity and elevated CK, is not typical for ADEM, and the MRI is unremarkable.
*Encephalitis*
- Encephalitis involves **brain inflammation**, manifesting as fever, altered mental status, and seizures, with CSF usually showing **lymphocytic pleocytosis**.
- The CSF in this patient is largely normal (minimal pleocytosis), and the prominent **muscle rigidity and very high CK** point away from uncomplicated encephalitis.
*Meningitis*
- Meningitis primarily involves **inflammation of the meninges**, characterized by fever, headache, nuchal rigidity, and photophobia, with CSF showing pleocytosis and abnormal protein/glucose.
- While the patient has fever and altered mentation, **nuchal rigidity is absent**, and the CSF findings (especially the normal cell count and glucose) do not support a diagnosis of meningitis.
Neuroleptic malignant syndrome US Medical PG Question 7: A 19-year-old woman, accompanied by her parents, presents after a one-week history of abnormal behavior, delusions, and unusual aggression. She denies fever, seizures or illicit drug use. Family history is negative for psychiatric illnesses. She was started on risperidone and sent home with her parents. Three days later, she is brought to the emergency department with fever and confusion. She is not verbally responsive. At the hospital, her temperature is 39.8°C (103.6°F), the blood pressure is 100/60 mm Hg, the pulse rate is 102/min, and the respiratory rate is 16/min. She is extremely diaphoretic and appears stiff. She has spontaneous eye-opening but she is not verbally responsive and she is not following commands. Laboratory studies show:
Sodium 142 mmol/L
Potassium 5.0 mmol/L
Creatinine 1.8 mg/dl
Calcium 10.4 mg/dl
Creatine kinase 9800 U/L
White blood cells 14,500/mm3
Hemoglobin 12.9 g/dl
Platelets 175,000/mm3
Urinalysis shows protein 1+, hemoglobin 3+ with occasional leukocytes and no red blood casts. What is the best first step in the management of this condition?
- A. Paracetamol
- B. Dantrolene
- C. Intravenous hydration
- D. Switch risperidone to clozapine
- E. Stop risperidone (Correct Answer)
Neuroleptic malignant syndrome Explanation: ***Stop risperidone***
- The patient's presentation with **fever, altered mental status, muscle rigidity**, and elevated **creatine kinase** after starting risperidone is highly suggestive of **neuroleptic malignant syndrome (NMS)**.
- The **first and most critical step** in managing NMS is to **immediately discontinue the offending antipsychotic medication**, as continuation can worsen the severe symptoms and increase mortality.
*Paracetamol*
- While the patient has a high fever (39.8°C), **paracetamol** (acetaminophen) alone is **insufficient** to address the underlying severe hyperthermia and other systemic effects of NMS.
- The fever in NMS is due to **muscle rigidity** and **dysregulation of the hypothalamic thermoregulatory center**, which requires more comprehensive management than antipyretics.
*Dantrolene*
- **Dantrolene** is a **muscle relaxant** often used in NMS to reduce muscle rigidity and hyperthermia by inhibiting calcium release from the sarcoplasmic reticulum.
- However, the **withdrawal of the causative agent** (risperidone) is always the **initial and most crucial management step** before or in conjunction with supportive medications like dantrolene or bromocriptine.
*Intravenous hydration*
- **Intravenous hydration** is an important **supportive measure** in NMS to manage dehydration, support renal function (due to potential **rhabdomyolysis** from elevated CK), and help with temperature regulation.
- While critical, it is **not the *first* step**; discontinuing the causative drug is paramount.
*Switch risperidone to clozapine*
- Switching to another antipsychotic, even clozapine, is **inappropriate** at this stage because the patient is experiencing a severe adverse reaction to an antipsychotic.
- Reintroducing another antipsychotic could **exacerbate NMS** or trigger a similar reaction, and the immediate priority is to stabilize the patient by removing the trigger.
Neuroleptic malignant syndrome US Medical PG Question 8: A 37-year-old man with a history of schizophrenia, obesity, anxiety, recurrent pneumonia, and depression is brought to the emergency department. He was recently discharged from inpatient psychiatric care where he was treated for an acute psychotic episode with fluphenazine and started on a new antidepressant. One week after discharge, during a period of cold weather, he is found outdoors confused and poorly dressed. His rectal temperature is 93.2°F (34°C). Which of the following medications is most likely contributing to his hypothermia?
- A. Fluphenazine (Correct Answer)
- B. Valproic acid
- C. Diphenhydramine
- D. Fluoxetine
- E. Lithium
Neuroleptic malignant syndrome Explanation: **Fluphenazine**
- **First-generation antipsychotics** like fluphenazine can impair the body's ability to **thermoregulate** by interfering with dopaminergic pathways in the hypothalamus, increasing susceptibility to hypothermia in cold environments.
- Given the patient's recent discharge from inpatient care and exposure to cold weather while poorly dressed, the addition of an antipsychotic affecting thermoregulation strongly contributes to his hypothermia.
*Valproic acid*
- Valproic acid is an **anticonvulsant** and **mood stabilizer** primarily used for bipolar disorder and epilepsy.
- While it can have various side effects, **hypothermia** is not a commonly reported or significant side effect of valproic acid.
*Diphenhydramine*
- Diphenhydramine is an **antihistamine** with significant **sedative** and **anticholinergic** properties.
- While it can cause sedation and anticholinergic effects that might impact a patient's awareness or ability to seek shelter, it is not directly implicated in causing hypothermia through thermoregulatory dysfunction.
*Fluoxetine*
- Fluoxetine is a **selective serotonin reuptake inhibitor (SSRI)** commonly used for depression and anxiety.
- While SSRIs can have various side effects, **hypothermia** is not a characteristic or significant side effect of fluoxetine.
*Lithium*
- Lithium is a **mood stabilizer** used primarily for bipolar disorder.
- **Hypothyroidism** is a known side effect of long-term lithium use, which could theoretically contribute to an inability to maintain body temperature, but it is less likely to cause acute hypothermia compared to antipsychotics directly affecting thermoregulation.
Neuroleptic malignant syndrome US Medical PG Question 9: A 67-year-old man presents to his primary care physician for fatigue. This has persisted for the past several months and has been steadily worsening. The patient has a past medical history of hypertension and diabetes; however, he is not currently taking any medications and does not frequently visit his physician. The patient has lost 20 pounds since his last visit. His laboratory values are shown below:
Hemoglobin: 9 g/dL
Hematocrit: 29%
Mean corpuscular volume: 90 µm^3
Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.3 mEq/L
Ca2+: 11.8 mg/dL
Which of the following is the most likely diagnosis?
- A. Intravascular hemolysis
- B. Vitamin B12 and folate deficiency
- C. Bone marrow aplasia
- D. Malignancy (Correct Answer)
- E. Iron deficiency
Neuroleptic malignant syndrome Explanation: **Malignancy**
- The patient's **unexplained weight loss**, worsening fatigue, and **anemia** are highly suspicious for an underlying malignancy.
- The elevated **calcium level (11.8 mg/dL)** suggests a paraneoplastic syndrome or bone involvement, which is common in many cancers (e.g., multiple myeloma, solid tumors with bony metastases).
*Intravascular hemolysis*
- This would typically present with signs of red blood cell destruction, such as **jaundice**, dark urine, and elevated **lactate dehydrogenase (LDH)**, none of which are mentioned.
- The **normocytic anemia (MCV 90 µm^3)** is less typical for acute hemolysis, which can sometimes cause macrocytosis due to reticulocytosis.
*Vitamin B12 and folate deficiency*
- These deficiencies primarily cause **macrocytic anemia**, characterized by an **elevated mean corpuscular volume (MCV)**, which is not present here (MCV is 90 µm^3).
- While fatigue can be a symptom, the unexplained weight loss and hypercalcemia point away from these as the primary diagnosis.
*Bone marrow aplasia*
- **Aplastic anemia** typically presents with **pancytopenia** (low red blood cells, white blood cells, and platelets), which is not indicated here beyond the anemia.
- This condition does not directly explain the significant weight loss or hypercalcemia.
*Iron deficiency*
- **Iron deficiency anemia** is typically a **microcytic, hypochromic anemia**, meaning the **MCV would be low**, which is not the case here (MCV is 90 µm^3).
- While it can cause fatigue, it does not explain the unexplained weight loss or hypercalcemia reported in this patient.
Neuroleptic malignant syndrome US Medical PG Question 10: A 39-year-old man comes to the physician because of a 3-month history of fatigue, decreased sexual desire, and difficulty achieving an erection. He has no past medical history except for a traumatic brain injury he sustained in a motor vehicle accident 4 months ago. At that time, neuroimaging studies showed no abnormalities. Physical examination shows bilateral gynecomastia and a thin white nipple discharge. Decreased production of which of the following is the most likely underlying cause of this patient's current condition?
- A. Gonadotropin-releasing hormone
- B. Thyrotropin-releasing hormone
- C. Luteinizing hormone
- D. Growth hormone
- E. Dopamine (Correct Answer)
Neuroleptic malignant syndrome Explanation: ***Dopamine***
- The patient's symptoms (fatigue, decreased sexual desire, erectile dysfunction, gynecomastia, galactorrhea) following a **traumatic brain injury (TBI)** are indicative of **hypopituitarism**, specifically affecting dopamine's inhibitory control over prolactin.
- **Dopamine** is produced in the hypothalamus and tonically inhibits **prolactin secretion** from the anterior pituitary; a decrease in dopamine can lead to elevated prolactin, causing the observed symptoms.
*Gonadotropin-releasing hormone*
- While TBI can cause **hypogonadism** due to GnRH deficiency, this would primarily lead to decreased LH/FSH and subsequent low testosterone, causing sexual dysfunction but not necessarily **galactorrhea** or **gynecomastia**.
- Decreased GnRH would result in low levels of LH and FSH, but the direct cause of gynecomastia and nipple discharge in this case is likely **hyperprolactinemia**.
*Thyrotropin-releasing hormone*
- TRH stimulates TSH release; a deficiency would lead to **central hypothyroidism** (fatigue, cold intolerance, weight gain), but it does not directly explain **gynecomastia** or **galactorrhea**.
- While TRH can stimulate prolactin secretion, a primary TRH deficiency would more prominently feature symptoms of hypothyroidism, which are not mentioned as the primary concern.
*Luteinizing hormone*
- A decrease in LH would lead to **decreased testosterone production** and symptoms like low sexual desire and erectile dysfunction. However, it does not directly cause **galactorrhea** or **gynecomastia** as seen in this patient.
- LH primarily acts on Leydig cells to produce testosterone; while low testosterone can cause gynecomastia, the nipple discharge points more strongly to **hyperprolactinemia**.
*Growth hormone*
- Growth hormone deficiency in adults can cause fatigue, decreased muscle mass, and central obesity but is not typically associated with **gynecomastia** or **galactorrhea**.
- A decrease in GH does not explain the breast-related symptoms observed in this patient.
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