This section reviews some of the more prominent alternate causes of dementia that need to be excluded when pursuing a diagnosis of Alzheimer's disease. In practice, this exclusion cannot be done with 100% precision. Consequently, the accuracy of the clinical diagnosis of Alzheimer's disease is approximately 85%. Brain biopsy, which is seldom performed in practice, is the only method of moving diagnostic accuracy to near 100%. There is yet no intervention that halts or reverses the underlying pathophysiology of Alzheimer's disease, so the invasive brain biopsy is rarely justified to confirm a diagnosis.