Inclusion Criteria:  Female patients aged 25-43 and the gestational age above 34 weeks, with diagnostic preeclampsia (Hypertension and proteinuria) occurring after the 20th week of gestation and cesarian section is indicated with systolic blood pressure above 160 and diastolic blood pressure above 100.albumin in urine ++ or +++. No cardiac, hepatic,renal nor neurological problems.  Exclusion Criteria:  Age: younger than 25 or older than 43. Pregnant females with mild preeclampsia. Patients with cerebro-vascular diseases, Glaucoma, Hepatic failure, Renal failure . patient who got their MgSO4 medication before the first reading of Optic nerve sheath diameter ONSD were also excluded.  History of allergy to dexamedotomidine.  -