A 39-year-old man is brought to the office by his wife who is concerned about his behavior over the past year. She says, "He used to be outgoing and upbeat, but now he seems uncharacteristically depressed and distant from the family. He has lost interest in his work and has difficulty making decisions." Over the past month, he has become increasingly paranoid and believes that his business partner is trying to kill him. The patient has no psychiatric history. Both his father and grandfather were hospitalized in long-term care facilities and died in their 50s. Physical examination shows random, abrupt, uncoordinated movements of the left leg. On mental status examination the patient is restless and irritable. He is convinced that not only his business partner but also the government is out to harm him. Which of the following is the most likely diagnosis?

Question

A 39-year-old man is brought to the office by his wife who is concerned about his behavior over the past year.  She says, "He used to be outgoing and upbeat, but now he seems uncharacteristically depressed and distant from the family.  He has lost interest in his work and has difficulty making decisions."  Over the past month, he has become increasingly paranoid and believes that his business partner is trying to kill him.  The patient has no psychiatric history.  Both his father and grandfather were hospitalized in long-term care facilities and died in their 50s.  Physical examination shows random, abrupt, uncoordinated movements of the left leg.  On mental status examination the patient is restless and irritable.  He is convinced that not only his business partner but also the government is out to harm him.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient's development of psychiatric symptoms in his late-30s, abnormal choreiform movements (rapid and unpredictable contractions affecting mostly distal limbs), and family history are suggestive of Huntington disease (HD). HD is an autosomal dominant, progressive neurodegenerative disorder characterized by chorea, psychiatric symptoms, and subsequent dementia. Onset in mid-life is most common. There is no known cure and treatment is symptomatic. Psychiatric symptoms are highly prevalent in HD and may occur prior to the onset of chorea. They may include irritability, anxiety, apathy, depression, and psychosis (eg, delusions, hallucinations). Dementia develops later in the disease course and is characterized by prominent executive dysfunction. The diagnosis of HD is confirmed by testing for trinucleotide (cytosine-adenine-guanine [CAG]) repeat expansion in the huntingtin (HTT) gene. (Choices A, B, and H) These are primary psychotic disorders that would not be diagnosed when psychosis is due to a medical condition. Brief psychotic disorder is characterized by ≥1 psychotic symptoms lasting ≥1 days and ≤1 month with full return to the previous level of functioning. Delusional disorder is characterized ≥1 delusions lasting ≥1 month. Schizophrenia typically has onset in young adulthood and is characterized by psychotic symptoms (eg, delusions, hallucinations, disorganization, negative symptoms) lasting ≥ 6 months. (Choice C) Friedreich ataxia, the most common hereditary ataxia, is characterized by neurologic dysfunction, cardiomyopathy, and diabetes mellitus. (Choices E and G) Although this patient has both mood and psychotic symptoms, they are more likely manifestations of HD given his movement abnormalities. In major depression with psychotic features, psychosis occurs exclusively during the depression. In schizoaffective disorder, patients show evidence of psychosis when they are not depressed. (Choice F) Parkinson disease (PD) is a progressive neurodegenerative disease characterized by tremor, bradykinesia, and rigidity. Psychosis can also occur in PD but typically presents later in the disease course. PD is less likely in this patient with early psychiatric findings, choreiform movements, and absence of other neurological findings of PD (eg, tremor, bradykinesia). Educational objective: Huntington disease is an autosomal dominant, progressive neurodegenerative disorder characterized by chorea, psychiatric symptoms, and dementia. Psychiatric symptoms may occur early in the disease course and include irritability, anxiety, apathy, depression, and psychosis. __________ References: Longitudinal psychiatric symptoms in prodromal Huntington's disease: a decade of data. (http://www.ncbi.nlm.nih.gov/pubmed/26472629)

A 39-Year-Old Man Is Brought to the Office by His