<prompt> One of the following is a reversible cause of dementia -Toxic dementiaAlzheimers ds.Multi-infarct dementiaPick ds.  <response>: Reversible causes of dementiaSurgically treatable:- Normal pressure hydrocephalus, brain tumors frontal lobe tumor, meningioma, subdural hematoma due to head injury, hydrocephalus.Medically treatable:- Depression, hypothyroidism, alcohol abuse, vitamin B 12folateNiacin deficiency, any metabolic or endocrine disturbance, neurosyphilis, Hashimotos encephalopathy, Wilsons disease, celiac disease, Whipples disease, chronic meningoencephalitis, drugs and toxin toxic dementia.Irreversible causes of dementia:- Alzheimers disease, vascular multi-infarct dementia, Parkinsonism, Huntingtons chorea, Lewy body dementia, Picks disease. 