<prompt> A pt. is brought to the casualty in the state of altered sensorium. He was on lithium tt for affective disorder and has suffered through an attack of epileptic fits. On examination he has tremors increased DTRs and incontinence of urine. He has also undergone an episode of severe gastroenteritis 2 days ago. The serum lithium was found to be 1.95 m molesL. The cause of her condition is :Lithium toxicityDehydrationManic episodeDepressive stupor  <response>: Ans. is a i.e. Lithium toxicityI am not sure on this One.The symptoms of the pt. can be attributed to C.N.S. toxicity occuring dt lithium overdose but K.D.T. says that serum level of Lithium required to cause CNS symptoms is above 2 meq.The Symptoms can also be attributed to dehydration occuring dt gastroenteritis.The dehydration is aggravated by polyurea occuring dt lithium This adverse effect of lithium can occur at serum level above 1.5 meq.Goodman Gilman says that lithium toxicity occurs in - Acute therapy at serum level - 4 meq. Chronic therapy at serum level - 1.5 meq.The pt. in question seems to be undergoing chronic therapy with lithium.Therefore I find lithium toxicity, the more correct choice.I have given you the facts, you can decide for yourself. 