A 75-year-old man is brought to the office by his daughter due to increasing confusion over the past 3 weeks. His daughter noticed that he has had trouble writing, using a computer, and keeping track of his calendar. The patient's wife died 4 weeks ago and since then, he has not been sleeping well and taking doxylamine at bedtime has not helped much. Other medical conditions include chronic obstructive pulmonary disease and hypertension. The patient takes amlodipine and tiotropium. Temperature is 36.1 C (97 F), blood pressure is 140/90 mm Hg, pulse is 105/min, and respirations are 18/min. The patient is oriented to person but not to time or place. Extraocular movements are normal. Lungs are clear to auscultation bilaterally. Reflexes are 2+ and strength is normal. His gait is ataxic and his speech is dysarthric. Complete blood count, urinalysis, and serum chemistries are normal. CT scan of the head reveals mild cortical atrophy but is otherwise normal. Which of the following is the most appropriate next step in management?

Question

A 75-year-old man is brought to the office by his daughter due to increasing confusion over the past 3 weeks.  His daughter noticed that he has had trouble writing, using a computer, and keeping track of his calendar.  The patient's wife died 4 weeks ago and since then, he has not been sleeping well and taking doxylamine at bedtime has not helped much.  Other medical conditions include chronic obstructive pulmonary disease and hypertension.  The patient takes amlodipine and tiotropium.  Temperature is 36.1 C (97 F), blood pressure is 140/90 mm Hg, pulse is 105/min, and respirations are 18/min.  The patient is oriented to person but not to time or place.  Extraocular movements are normal.  Lungs are clear to auscultation bilaterally.  Reflexes are 2+ and strength is normal.  His gait is ataxic and his speech is dysarthric.  Complete blood count, urinalysis, and serum chemistries are normal.  CT scan of the head reveals mild cortical atrophy but is otherwise normal.  Which of the following is the most appropriate next step in management?

Quizplus · Accepted Answer

11ec25c8_d15f_66ed_bc81_d33f2962a623_MD0003_00 This patient's memory impairment, ataxia, and dysarthria that developed 3 weeks after initiation of doxylamine (an anticholinergic sleeping medication) is most likely due to chronic anticholinergic toxicity caused by the combined anticholinergic effects of doxylamine and tiotropium. Many medications with anticholinergic properties can cause toxicity at therapeutic doses, particularly in combination; elderly psychiatric patients taking multiple medications and young children are at highest risk. Removal of the anticholinergic medication generally leads to symptom resolution; therefore, doxylamine should be discontinued in this patient. Chronic anticholinergic toxicity often presents with subtle, nonspecific symptoms (eg, confusion, altered mental status, dysarthria), and more classic findings typical of acute toxicity (eg, tachycardia, hyperthermia, flushed dry skin, urinary retention) are often absent. Therefore, anticholinergic toxicity should always be considered in patients taking multiple medications with nonspecific symptoms. For example, impaired memory, gait disturbance, and confusion (common in the elderly) may be mistakenly attributed to aging or other disease processes when the actual cause is cumulative anticholinergic effects. (Choice A) Donepezil is a cholinesterase inhibitor used to treat Alzheimer dementia (AD), which has an insidious onset. This patient's rapid onset of symptoms (3 weeks) is not consistent with AD. (Choice B) Selective serotonin reuptake inhibitors are primarily used to treat depression. Although this patient's cognitive impairment and sleep disturbance could be caused by depression, his abnormal neurologic examination (gait ataxia and dysarthria) is inconsistent with a psychiatric diagnosis. (Choice D) An electroencephalogram (EEG) can be used to characterize and stage dementia. The rapid onset of symptoms in this patient is suggestive of an alternate diagnosis and an EEG would not be the next best step. (Choice E) Pre- and post-lumbar puncture gait assessment is used to diagnose normal pressure hydrocephalus (NPH), a condition characterized by a change in mental status, ataxia, and incontinence (not present in this patient). A rapid time course is uncommon in NPH, and abnormal findings (eg, ventricular enlargement) would likely be present on CT scan of the head. (Choice F) Transfer to an assisted living facility could be appropriate in patients diagnosed with dementia and at risk for falls. However, a thorough evaluation for reversible causes of a patient's symptoms should be performed first. Educational objective: Patients treated with multiple anticholinergic medications (eg, elderly psychiatric patients) are at risk for chronic anticholinergic toxicity, which often presents with subtle and nonspecific findings not typical of acute anticholinergic toxicity. Removal of the anticholinergic medication leads to resolution of symptoms. References: Chronic anticholinergic use and the aging brain. (http://www.ncbi.nlm.nih.gov/pubmed/23183138)

A 75-Year-Old Man Is Brought to the Office by His