CASE: Agitated and paranoid
Police bring Mr. L, age 85, to the emergency department (ED) because he threatened his wife, claiming she is having an affair. Two days earlier, he was discharged from a different hospital, where he was treated for progressive and fluctuating irritability, depressed mood, confusion, disorientation, inattention, and delusional thinking that had started 4 to 5 months earlier. He has no other psychiatric history.
Mr. L has a history of atrial fibrillation, hypertension, benign prostatic hypertrophy, and noninsulin-dependent diabetes mellitus. Several months ago, he had hip surgery, which was complicated by a surgical wound infection. Medications include digoxin, 0.125 mg/d; atenolol, 100 mg/d; warfarin, 1 mg/d on Monday, Wednesday, Friday, Saturday, and Sunday and 0.5 mg/d Tuesday and Thursday; lisinopril, 40 mg/d; tamsulosin, 0.4 mg/d; and glyburide, 1.25 mg/d. During the previous hospitalization, physicians discovered he had myasthenia gravis, which they treated with prednisone and pyridostigmine. Mr. L also was diagnosed with hyperaldosteronism. An adrenal mass was found in an abdominal CT. At that time, he also was diagnosed with major depressive disorder (MDD) with psychotic features and started on aripiprazole, 10 mg/d, mirtazapine, 30 mg/d, and trazodone, 50 mg/d for sleep.
The authors’ observations
When evaluating mental status changes in older patients, consider the time course and characteristics of the changes, especially if the patient’s cognitive function changes. Acute mental status changes that occur over hours to days often represent delirium caused by a medical condition such as a coronary event or infection. Changes that develop over weeks to months often signal a primary psychiatric disorder such as depression, mania, or dementia. Mr. L’s mood and psychotic symptoms developed over 4 to 5 months and were thought to be a result of MDD with psychotic features. However, his fluctuating cognitive symptoms, confusion, and lack of psychiatric history suggest that the differential diagnosis should include a cognitive disorder such as delirium or dementia. The hypoactive form of delirium often is unrecognized or misdiagnosed as sedation or depression, particularly in older patients.1
Multiple medical conditions and polypharmacy are important factors to consider when evaluating mental status changes in geriatric patients. In Mr. L’s case, atrial fibrillation, hypertension, and diabetes increase his risk of an acute cardiovascular or cerebrovascular event and chronic cerebrovascular disease. Hyperaldosteronism can lead to electrolyte abnormalities that may produce mental status changes. Treatment with an oral hypoglycemic raises the possibility that hypoglycemia is contributing to his mental status changes. Prednisone can cause psychosis, anxiety, and mania. Digoxin toxicity is associated with psychosis and irritability. Pyridostigmine also has been reported to cause psychosis. Use of an antidepressant, such as mirtazapine, could have exacerbated an underlying undiagnosed bipolar disorder. Antipsychotics, such as aripiprazole, may cause akathisia or activation. Substance intoxication or withdrawal should not be excluded solely because a patient is older. In older patients, medications with anti-cholinergic effects are common culprits for cognitive impairment (Table 1).2,3
Table 1
Medications that could contribute to mental status changes
| Anticholinergics (atropine, benztropine, oxybutynin, some OTC medications) |
| Hypnotics/sedatives (benzodiazepines) |
| Opiate analgesics (meperidine) |
| Neuroleptics (clozapine, thioridazine, olanzapine) |
| Antiparkinsonian medications (levodopa, selegiline, pergolide, amantadine) |
| Antidepressants (amitriptyline) |
| Anticonvulsants (phenytoin) |
| Histamine H2 receptor antagonists (ranitidine, cimetidine, omeprazole) |
| Cardiac drugs (digoxin) |
| Nonsteroidal anti-inflammatory drugs (aspirin) |
| Corticosteroids (prednisolone) |
| Antibiotics (penicillins, cephalosporins, quinolones) |
| OTC: over the counter Source: References 2,3 |
ASSESSMENT: More problems
At admission to the medical unit, Mr. L’s temperature is 36.7°C (98°F), with a heart rate of 77 beats per minute, respiratory rate of 24 breaths per minute, and blood pressure of 164/84 mm Hg with oxygen saturation of 96% at room air. Physical exam is notable for 2+ pitting edema in the lower extremities. Mr. L is oriented to person, place, and time and is psychomotorically activated. Neurologic examination is within normal limits.
Laboratory data reveal a potassium level of 2.5 mEq/L. Other results, including complete blood count, comprehensive metabolic panel, thyroid-stimulating hormone, urinalysis, urine toxicology screen, B12, folate, venereal disease research laboratory, and ammonia are unremarkable. Chest radiography reveals an enlarged cardiomediastinum. A CT scan of the brain without contrast shows cortical volume loss and periventricular white matter disease without evidence of acute intracranial abnormality. ECG shows atrial fibrillation with a rate of 67 beats per minute.
Mr. L’s hypokalemia is corrected with potassium chloride and his hyperaldosteronism is treated with spironolactone, 25 mg/d. Physicians on the medical unit discontinue digoxin because Mr. L’s heart rate is controlled with atenolol and he is anticoagulated with warfarin.