February Case Of The Month

NMS Hotline Case Of The Month

A 63 Year-Old With Small Bowel Obstruction

A 63-year-old resident at a home for the mentally ill presented with small bowel obstruction (partial). The patient had some agitation. She had been on olanzapine (Zyprexa) but was treated with IM haloperidol and Lorazepam for the past few days. Her temperature had gone up to 102 degrees – 105 degrees F. She had tachycardia but did not have rigidity. She had an impaired mental status but her baseline mental status was not known. She may have had cog wheeling at the time of onset, several days ago. CPK is 51.

1. Can a patient be diagnosed with NMS with a normal CPK?

A. False No, it is not an essential criterion, but is helpful in management
B. True Yes, the CPK needs to exceed 1000 to count as NMS

2. NMS can be diagnosed in a patient with mental retardation and mental status changes, or where the baseline mental status is not known.

A. True
B. False

3. If bowel obstruction is responsible for hyperthermia and autonomic changes, then can NMS be diagnosed?

A. Yes
B. No

4. What about rigidity? If cogwheel rigidity was present only on admission could this patient still have NMS?

A. Yes
B. No

Answers:

1. Yes - the CPK is associated finding, but NMS cannot be ruled out based on one normal CPK.

2. True - NMS has been reported in patients with mental retardation. NMS can still be diagnosed in a patient with agitation, confusion, stupor, coma or delirium. It may be helpful to contact family or caregivers to find out if the patient's current mental status is different from the baseline.

3. No - NMS is a diagnosis of exclusion. Other causes of hyperthermia and autonomic changes should be identified, and if peritonitis or sepsis is responsible in this case then that takes precedence, especially given the incomplete symptom picture of NMS (absence of rigidity, catatonia, CPK elevations). Nonetheless, stopping antipsychotics and providing supportive care were recommended. A patient could have more that one diagnosis, and haloperidol could have caused NMS-like symptoms in addition to sepsis.

4. Yes - there are cases of in which rigidity is transient or mild.