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What is A patient of schizophrenia was staed on haloperidol 5 mg. Next day, he presented with uprolling of eyes. Complete neurological examination revealed no spasticity or any other abnormality. Visual acuity and ophthalmoscopic findings are normal. Most likely diagnosis is : and explain in detail?
Acute muscular dystonia is the earliest appearing extrapyramidal symptom caused by antipsychotic drugs like haloperidol. REF: HARRISONS 20TH ED.