A 30 year old man who was recently started on haloperidol 30mg/day developed hyperpyrexia, muscle rigidity, akinesia, mutism, sweating, tachycardia and increased blood pressure. The investigations showed increased WBC count, increased creatinine phosphokinase. There is no history of any other drug intake or any signs of infection. The most likely diagnosis -
Features of neuroleptic malignant syndrome 

Marked muscular rigidity                            
High fever                                                            
Autonomic instability (↑ HR & BP, Sweating)  
Disturbed consciousness   
Catatonia & stupor
Leucocytosis     
Increased CPK   
Myoglobinemia & Myoglobinuria
Drug overdose
Neuroleptic malignant syndrome
Drug induce Parkinsonism
Tardive dyskinesia