Movement disorder emergencies in the elderly: Recognizing and treating an often-iatrogenic problem
ABSTRACTMovement disorder emergencies in the elderly—such as rigidity, dystonia, hyperkinetic movements, and psychiatric disturbances—are challenging to manage. Many cases are iatrogenic. In theory, some cases could be avoided by anticipating them and by avoiding polypharmacy and potentially dangerous drug interactions.
KEY POINTS
- Supportive measures must be taken immediately to maintain the functions of vital organs.
- Serotonin syndrome, which can cause rigidity or stiffness, can be prevented by avoiding multidrug regimens.
- Withdrawing or decreasing the dose of dopaminergic drugs in patients with Parkinson disease can cause parkinsonism-hyperpyrexia syndrome, a condition similar to neuroleptic malignant syndrome.
- Metoclopramide (Reglan) accounts for nearly one-third of all drug-induced movement disorders. The entire spectrum of drug-induced movement disorders, ranging from subtle to life-threatening, can ensue from its use.
- Complications of Parkinson disease include hallucinations, dementia, depression, psychosis, and sleep disorders.
DISORDERS WITH PSYCHIATRIC PRESENTATIONS
Hallucinations and psychosis in Parkinson disease
Neuropsychiatric or behavioral complications of Parkinson disease include hallucinations, dementia, depression, psychosis, and sleep disorders.21,26 Psychosis is the leading reason for nursing home placement in advanced cases.27 Psychosis can present as hallucinations or a paranoid delusional state in association with clear sensorium.28 However, hallucinations accounted for only 3% of emergency admissions to the hospital for Parkinson disease patients in one series.29
Risk factors for hallucinations in parkinsonian patients include dementia, long-term therapy with dopaminergic drugs, long duration of disease, advanced age, anticholinergic drugs, and sleep disorders. Severe cognitive impairment or dementia is a major and independent predictive factor for visual hallucinations.30
Most hallucinations are visual; auditory, tactile, and olfactory hallucinations are rare.30
Treatment initially should be the same as in any patient with delirium. The systemic disorders that can aggravate or cause hallucinations such as electrolyte abnormalities, urinary or respiratory infection, and systemic illness should be ruled out.
The next step is to reduce or discontinue the adjunctive drugs that have the least antiparkinsonian effect and the greatest potential of inducing hallucination or psychosis. Examples of such medications include histamine-2 antagonists (eg, cimetidine [Tagamet], amantadine, selegeline, and anti-cholinergics). Selegeline can be discontinued abruptly because it has a long duration of action in the brain, but amantadine and anti-cholinergics should be tapered. Dopamine agonists can be discontinued. Levodopa can be reduced until the side effects begin to subside without significant worsening of motor symptoms.
If all the above adjustments fail, an antipsychotic medication can be considered.26 Clozapine (Clozaril) has the best result and is nearly free of extrapyramidal side effects but can cause agranulocytosis, which requires frequent blood counts. The Parkinson Study Group suggested that clozapine, at daily doses of 50 mg or less, is safe and significantly improves drug-induced psychosis without worsening parkinsonism.31 Clozapine may be impractical for elderly patients due to its side effect profile.
Quetiapine is a good alternative to cloza-pine and is less likely to worsen parkinsonian symptoms than other atypical antipsy-chotics.32 Olanzapine and risperidone (Risperdal) are reported to worsen parkinsonian symptoms.33 Not enough data have been published about the efficacy of the newer medications such as ziprasidone (Geodon) and aripiprazole (Abilify) to advocate their routine clinical use.
Rivastigmine (Exelon) was reported to improve hallucinations, sleep disturbance, and caregiver distress in addition to enhancing cognitive performance in advanced Parkinson disease in a small study.34 Burn and colleagues35 reported that rivastigmine was beneficial in patients with dementia associated with Parkinson disease, with or without hallucinations. Efficacy measures were cognitive scales, activities of daily living, behavioral symptoms, and executive and attentional functions. The differences in these measures between rivastigmine and placebo recipients tended to be larger in patients with visual hallucinations than in those without hallucinations. The study was not designed to assess the effect of treatment on psychosis or hallucination.
WHEN PATIENTS WITH MOVEMENT DISORDERS NEED SURGERY
Some of these syndromes can be prevented, especially in patients who are known to have movement disorders and are undergoing surgery.
One problem is stopping oral dopaminergic drugs before the operation. Parkinson disease patients on dopaminergic drugs can develop parkinsonism-hyperpyrexia syndrome or akinetic crisis if the drug is stopped suddenly. Restarting dopaminergic therapy and supportive measures are the main treatments. Patients who have Parkinson disease should receive their usual dose of levodopa, dopamine agonist, or amantadine up until the time of surgery and then again as soon as they awaken in the recovery room.36 That goal can be achieved more easily now that these drugs come in transdermal patches and long-acting formulas.37 Droperidol (Inapsine) and metoclopramide worsen parkinsonism and should be avoided.
Myoclonus is the most common movement disorder seen in the postoperative period. In fact, myoclonic shivering is common as patients awaken from general anesthesia.36 The anesthetic agents etomidate (Amidate) and enflurane (Ethrane) and the opioids fentanyl (Actiq, Duralgesic, Sublimaze) and meperidine (Demerol) can cause myoclonus.38
Occasionally, a patient in the recovery room suddenly develops a neurologic deficit that is inconsistent with the history and physical findings. Psychogenic movement disorders should be considered in the differential diagnosis. Reassurance and occasionally psychiatric intervention are required in these cases.36
IN THE ELDERLY, GO EASY
Polypharmacy is a huge issue in the elderly. Some of the principles in prescribing medications in the elderly can be helpful in preventing movement disorder emergencies:
- Assess the current regimen, including over-the-counter drugs, before prescribing a new drug.
- Begin with a low dose and increase as necessary. “Start low, go slow.”
- Consider the possibility that any new symptoms can be a drug side effect or due to withdrawal of a drug.
- Discuss with the patient or caregiver what kind of side effect to expect and advise him or her to report serious ones.
