Case for discussion.
A 92 year old female with complaints of cough, fever, chest pain since past 2 days was admitted to the hospital. She also had a recent history of zoster infection. On investigation, the X-ray showed pleural effusion. She was diagnosed with pneumonia and had started treatment with IV antibiotics. On the third night in the hospital, the patient became agitated and restless as result of hospital acquired delirium. She was given haloperidol to calm her. In about 4-6 hours, the patient developed muscle rigidity, became febrile and felt dizzy. The lumbar puncture showed no significant findings. Her CPK levels were elevated.
What could be the diagnosis?