A 77-year-old woman is brought to the office by her son due to frequent falls and confusion. The patient began to fall without clear provocation 2 years ago. Her family didn't think anything of the falls until she began having episodes of confusion a year ago. The patient's son says, "She has good and bad days. On good days she seems almost like her old self, but on bad days she appears confused and is difficult to understand." He adds that she sometimes appears to be distracted and agitated by people or things that he cannot see. The patient's medical history includes hypertension and coronary artery disease; her mother died of a stroke and her father had several heart attacks. Temperature is 37.2 C (98.9 F), blood pressure is 140/86 mm Hg, pulse is 84/min, and respirations are 16/min. Her movements and speech are slow, she has a short-stepped gait and rigidity in her upper extremities. Montreal Cognitive Assessment is 20 on a scale of 0-30 (normal: ≥26). The patient is prescribed donepezil, carbidopa levodopa, and risperidone. Two weeks after the initial office visit, she is brought to the emergency department by her son due to increasing confusion and falls. Supine blood pressure and pulse are 124/82 mm Hg and 65/min, respectively; standing blood pressure and pulse are 98/74 mm Hg and 87/min. The patient is not oriented to person, place, or time. Examination shows cranial nerves are within normal limits. Rigidity is present in both upper and lower extremities on passive movement. Upper and lower limb deep tendon reflexes are 2+. Which of the following is the most likely explanation for this patient's symptoms?

Question

A 77-year-old woman is brought to the office by her son due to frequent falls and confusion.  The patient began to fall without clear provocation 2 years ago.  Her family didn't think anything of the falls until she began having episodes of confusion a year ago.  The patient's son says, "She has good and bad days.  On good days she seems almost like her old self, but on bad days she appears confused and is difficult to understand."  He adds that she sometimes appears to be distracted and agitated by people or things that he cannot see.  The patient's medical history includes hypertension and coronary artery disease; her mother died of a stroke and her father had several heart attacks.  Temperature is 37.2 C (98.9 F), blood pressure is 140/86 mm Hg, pulse is 84/min, and respirations are 16/min.  Her movements and speech are slow, she has a short-stepped gait and rigidity in her upper extremities.  Montreal Cognitive Assessment is 20 on a scale of 0-30 (normal: ≥26). The patient is prescribed donepezil, carbidopa levodopa, and risperidone.  Two weeks after the initial office visit, she is brought to the emergency department by her son due to increasing confusion and falls.  Supine blood pressure and pulse are 124/82 mm Hg and 65/min, respectively; standing blood pressure and pulse are 98/74 mm Hg and 87/min.  The patient is not oriented to person, place, or time.  Examination shows cranial nerves are within normal limits.  Rigidity is present in both upper and lower extremities on passive movement.  Upper and lower limb deep tendon reflexes are 2+.  Which of the following is the most likely explanation for this patient's symptoms?

Quizplus · Accepted Answer

Explanation: Pharmacotherapy for dementia with Lewy bodies (DLB) includes cholinesterase inhibitors for cognitive impairment, carbidopa-levodopa for parkinsonism, and melatonin for REM sleep behavior disorder. Antipsychotics may be used to treat functionally impairing visual hallucinations or delusions in patients with DLB; however, physicians should be aware that patients with DLB are extremely sensitive to antipsychotics. The use of antipsychotics in DLB may be associated with a significant worsening of confusion, parkinsonism, or autonomic dysfunction. This patient's acute exacerbation of symptoms is most likely due to recent initiation of risperidone, a drug with stronger dopamine receptor antagonism compared to other second-generation antipsychotics. When antipsychotics are necessary, evidence favors low-potency second-generation antipsychotics (eg, quetiapine) to reduce the risk of severe reactions. First-generation antipsychotics (eg, haloperidol) should be avoided entirely. In addition to severe antipsychotic sensitivity associated with DLB, antipsychotic drugs are associated with increased mortality in elderly patients with dementia. (Choice A) Anti-Parkinson therapy would not explain this patient's worsening confusion and parkinsonian symptoms. Anti-Parkinson drugs have been associated with exacerbation of psychotic symptoms in DLB, but this risk can be minimized by careful dose titration and judicious, as-needed use of low-dose antipsychotics. (Choice C) The most clinically significant side effects of cholinesterase inhibitors are diarrhea, vomiting, and bradycardia. (Choice D) Patients with postural tachycardia syndrome do not exhibit associated confusion and typically do not have arterial hypotension with standing. This patient's autonomic dysfunction is a feature of her DLB. (Choice E) Although cognitive impairment and/or parkinsonism may worsen as DLB progresses, the rapidity of the patient's deterioration combined with the recent prescription of new medication suggest that the best explanation for her worsened symptoms is the antipsychotic. Educational objective: Patients with dementia with Lewy bodies (DLB) are extremely sensitive to antipsychotics, and their use may be associated with an exacerbation of confusion, parkinsonism, and/or autonomic dysfunction. For DLB patients with functionally impairing visual hallucinations, low-dose, low-potency, second-generation antipsychotics (eg, quetiapine) are preferred over first-generation antipsychotics. References: Diagnosis and management of cognitive and behavioral changes in dementia with Lewy bodies. (http://www.ncbi.nlm.nih.gov/pubmed/28990131)

A 77-Year-Old Woman Is Brought to the Office by Her