Review Question - QID 215160

This patient’s presentation with sudden behavioral changes that are indicative of impaired impulse control (hypersexuality and pathologic gambling) in the setting of the recent initiation of dopamine agonist therapy, pramipexole, suggests the development of an impulse control disorder. Impulse control disorders are a known side effect of dopamine agonist therapy.

There are 3 main dopaminergic pathways in the central nervous system, consisting of the nigrostriatal pathway, mesocorticolimbic pathway, and tuberoinfundibular pathway. Parkinson disease is caused by degeneration of the nigrostriatal pathway. Thus, dopamine agonists (e.g., pramipexole, ropinirole, or bromocriptine) are used in the initial treatment of Parkinson disease, especially in younger patients. However, these drugs also activate the mesocorticolimbic pathway, which controls the reward system. This agonism is thought to amplify existing behavioral tendencies, leading to compulsive reward-seeking behavior that can manifest as hypersexuality, pathologic gambling, and/or compulsive shopping. Patients and caretakers should receive education on these potential side effects when dopamine agonist therapy is initiated. If an impulse control disorder develops, dopamine agonist therapy should be tapered until the impulse control disorder resolves.

Incorrect Answers:
Answer 1: Alzheimer dementia can present with behavioral changes in the later stages, which commonly include agitation, aggression, and psychosis. The hallmark of early Alzheimer dementia is memory changes. Hypersexuality and pathologic gambling would be unexpected.

Answer 2: Frontotemporal dementia can present with disinhibition and compulsive behaviors due to damage of the brain areas responsible for executive function. Other findings such as cognitive changes, apathy, loss of sympathy, and/or hyperorality may be present. However, the diagnosis of frontotemporal dementia requires the exclusion of other disorders that could account for the behavioral disturbances, and medication side effect is a more likely explanation given the timing of symptoms in this patient.

Answer 3: Histrionic personality disorder is characterized by a pervasive pattern of emotional overreaction, attention-seeking, and seductive behavior beginning in early adulthood. Inappropriate sexually seductive or provocative behavior is common. The timing of this patient’s behavioral changes (i.e., relation to the initiation of dopamine agonist therapy) is more consistent with a medication side effect.

Answer 4: Kluver-Bucy syndrome is a rare neurological disorder characterized by apathy, visual agnosia, hypersexuality, and/or hyperorality due to bilateral amygdala lesions. The timing and relation of this patient’s behavioral changes to the initiation of dopamine agonist therapy are more consistent with a medication side effect.

Bullet Summary:
Impulse control disorders, such as hypersexuality, pathologic gambling, and/or compulsive shopping, are known side effects of dopamine agonist therapy (e.g., pramipexole, ropinirole, and bromocriptine).