Annals of Long Term Care

A case of neuroleptic malignant syndrome (NMS) in a nursing facility resident that was initially misdiagnosed as a urinary tract infection is presented. The author reviews the etiology and diagnosis of NMS, including the differential diagnosis, and discusses how other syndromes can generate similar symptoms.

_____________________

The Case

Mrs. F is a 64-year-old female resident in a skilled nursing facility (SNF) with a history of early-onset dementia of the Alzheimer’s type, who was noted by staff at the facility to be more confused and restless. The patient developed a fever with a Tmax of 102.2 degrees F, and was evaluated by her primary care physician in the SNF. The nursing staff also reported that she had difficulty swallowing with dysphagia. Upon examination, a urinalysis was ordered, and the patient was diagnosed with a UTI. Review of symptoms and physical exam did not elicit a cough or any respiratory symptoms. A chest x-ray was negative for infiltrate. A course of antibiotics was started for her infection. She had been on her medication course of risperidone 2 mg twice a day, lorazepam 1 mg three times a day, and trazodone 50 mg twice a day since being discharged from an inpatient geriatric psychiatric unit two months earlier. The medical doctor also added quetiapine 12.5 mg twice a day to her medication regimen for breakthrough agitation.

Two days later a psychiatric evaluation was ordered for worsening agitation and anxiety with restlessness. On evaluation by the psychiatrist, the patient was reported by the nursing staff to be more lethargic and disorganized than her baseline. The patient exhibited restlessness and was very fidgety. Poor eye contact and resistance with questioning and commands were noted. On physical exam there was moderate to severe lead-pipe rigidity of both arms at the wrists and elbows.

A creatinine phosphokinase (CPK) level was ordered and found to be elevated at 800 IU/L. The white blood cell count was elevated on her complete blood count without a left shift. Her liver transaminases were also mildly elevated from a normal baseline with an aspartate aminotransferase (AST) of 68 and an alanine aminotransferase (ALT) of 58. Her renal function was normal, and she had no myoglobin in her serum or urine. She had a normal computed tomography scan of her head.

The risperidone and quetiapine were stopped immediately. The lorazepam was increased to 4 mg per day. She was given oral and intravenous fluids in the facility. A follow-up CPK the next day showed a level of 400 IU/L, and it continued to trend down, returning to normal in the next three days. Her temperature normalized in the next two days, and her rigidity was significantly improved. On exam, the patient was alert and much calmer. Two weeks later, she began to become psychotic and agitated again, and so was restarted on risperidone 0.5 mg three times daily. On follow-up up to two months later she did not exhibit any evidence of NMS.

_____________________

Discussion
A large percentage of patients in skilled nursing facilities are treated with antipsychotic agents for a variety of disorders ranging from dementia with psychosis to schizophrenia. Neuroleptic malignant syndrome is a rare but dangerous complication of antipsychotic medication use,1 a form of drug-induced hyperthermia.2 The presentation and course of NMS can be variable and can range from benign and self-limiting to fatal in some cases if not recognized and diagnosed rapidly. The incidence of NMS varies from 0.02% to 3.23% but has been declining. It is more commonly seen with conventional antipsychotics than with the newer atypical agents. Neuroleptic malignant syndrome occurs in all ages and is found to be more common in males.3,4

The etiology appears to be related to specific antidopaminergic activity of antipsychotic medications. Central dopamine systems are involved in temperature regulation, as well as in regulation of muscle tone and movement.