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 PRESENTING WITH DYSTONIA
Acute dystonic reaction
Medications are a common cause of acute focal dystonia. The symptoms, which can be life-threatening, usually occur within 24 hours after taking the medication.12 The most common offenders are neuroleptic drugs and antiemetic drugs with dopamine-blocking activity (eg, metoclopramide), although in older patients, they are more likely to cause tardive dyskinesia and parkinsonism.13,14
Metoclopramide accounts for nearly one-third of all drug-induced movement disorders, and this adverse effect is a common reason for malpractice suits. The entire spectrum of drug-induced movement disorders, ranging from subtle to life-threatening, can ensue from its use; akathisia and dystonia are generally seen early in the course of metoclopramide-induced movement disorders, whereas tardive dyskinesia and parkinsonism seem to be more prevalent in long-term users.15
Treatment includes stopping the precipitating medication and reversing dystonia with anticholinergic medications such as benztropine (Cogentin). Anticholinergic therapy is given intravenously or intramuscularly followed by oral therapy for few days, as the acute dystonic reaction may recur after the effect of parenteral medication wears off.
Intravenous diphenhydramine (Benadryl), an antihistamine with additional anticholiner-gic effects, can abort dystonia in a few minutes.16
Laryngeal dystonia accompanied by multiple system atrophy
Multiple system atrophy, a Parkinson-plus syndrome, is characterized by parkinsonism (mostly with poor response to levodopa) and early onset of dysfunction of the autonomic nervous system, urinary tract, cerebellum, and corticospinal tract (hyperreflexia).17
In the course of the disease, about one-third of patients develop respiratory stridor due to abnormal movements of the vocal cords.18 Nocturnal stridor portends a poor prognosis,19 with an increased risk of sudden death. Geriatricians should be aware of these symptoms, as these patients may seek care because of hoarseness or difficulty swallowing.
Treatment. Laryngeal dystonia can be improved with continuous positive airway pressure. In some cases, tracheostomy may be needed.19
Sudden withdrawal of baclofen
Baclofen (Lioresal), a treatment for spasticity and dystonia, is delivered via a pump through a catheter into an intrathecal space. The pump needs to be refilled every 3 to 6 months. Sudden discontinuation of medication caused by a dislodged catheter tip or forgetting to refill the pump provokes withdrawal symptoms. Patients with this life-threatening syndrome can present with rigidity, fever, change in mental status, and worsening dystonic symptoms.
Treatment involves high doses of baclofen (up to 120 mg/day in divided doses).6
DISORDERS PRESENTING WITH HYPERKINETIC MOVEMENTS
Chorea, ballism (ballismus), and athetosis constitute a range of involuntary, hyperkinetic movement disorders. Chorea consists of involuntary, continuous, sudden, brief, unsustained, irregular movements that flow from one part of the body to another. Hemiballism presents as forceful flinging movements of the limbs or high-amplitude chorea that affects one side of the body.
Acute hemichorea and hemiballism
Acute hemichorea and hemiballism commonly result from infarction or hemorrhage of the basal ganglia.20 Computed tomography and especially magnetic resonance imaging can show the lesions in patients with ballism. Stroke-induced ballism is usually self-limited and resolves after a few weeks. Acute hemiballism generally evolves to hemichorea or hemiathetosis in a few days, which requires only protective measures.
Treatment. Mild cases do not need treatment but severe cases call for medical therapy. Antidopaminergics are the drugs of choice. A dopamine depletor such as reserpine (Serpasil) 0.1 mg once or twice daily or dopamine receptor blockers such as neuroleptics are considered.16 The combination of a benzodiazepine plus an antipsychotic such as olanzapine (Zyprexa) has been suggested.6
Severe parkinsonian dyskinesia
Dyskinesia is common in Parkinson disease, and patients may present to an emergency room with severe levodopa-induced dyskinesia. Dyskinesia can be exhausting if prolonged and severe. Elevated levels of creatine kinase raise the concern of rhabdomyolysis. In rare cases, the patient develops respiratory dyskinesia when respiratory muscles such as those in the diaphragm become involved.21
The risk of levodopa-induced dyskinesia increases with disease severity and higher levodopa doses. Using a dopamine agonist as initial therapy delays the onset of levodopa-induced dyskinesia in early Parkinson disease. However, Factor and Molho,21 in a case series, reported that adding dopamine agonists to the regimen was a precipitating factor; another was infection.
Treatment. A reasonable approach to treating peak-dose dyskinesia is to lower the doses of dopaminergic medications.
A mild sedative such as lorazepam, alprazolam (Xanax, Niravam), or clonazepam (Klonopin) may reduce the severity of dyski-nesia.21 These drugs are particularly useful if the dyskinesia is worse at night, and they can be used in the emergency department while waiting for the effect of the dopaminergic medications to wear off.
Amantadine ameliorates levodopa-induced peak-dose dyskinesia without worsening parkinsonian symptoms in some patients.22
Drug-induced myoclonus
Myoclonus is sudden, jerky, brief involuntary movement of the face, limbs, or trunk. Unlike tics, myoclonus cannot be controlled by the patient.
Myoclonus has various pathophysiologic mechanisms. Most myoclonic emergencies are epileptic myoclonic seizures, which are beyond the scope of this article. Often, myoclonus is caused by opiate overdose or withdrawal. It can also be a side effect of SSRIs, tricyclic anti-depressants, lithium, amantadine, and rarely, antibiotics such as imipenem (Primaxin).23
Treatment. Opiate-induced myoclonus may respond to naloxone (Narcan), whereas opiate withdrawal responds to benzodi-azepines.6
Acute akathisia
Acute akathisia occurs in susceptible patients after exposure to dopamine receptor blockers or dopamine depletors. It is characterized by subjective restless feelings accompanied by objective restless movements. The course is usually self-limited after the causative medication is discontinued.
Treatment. Symptomatic treatment may be needed in most cases for several days. Anticholinergics are effective. Additionally, vitamin B6, mianserine, propranolol, and mirtazapine (Remeron) in a low dose (15 mg/day) have been shown to be effective16,24,25
