This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S., Subject name: Medicine
Miller Fischer test is used for: 
Select and explain. 
A. Evaluating cognition in NPH., B. Severity of paralysis in GBS., C. Grading muscle involvement in ALS., D. Measuring disability in Multiple sclerosis.
A: Evaluating cognition in NPH.
Answer: A: Evaluating cognition in NPH. 
Explanation: Ans. A. Evaluating cognition in NPHEvaluating cognition in NPH. The CSF tap test, sometimes lumbar tap test or Miller Fisher Test, is a medical test that is used to decide whether shunting of cerebrospinal fluid (CSF) would be helpful in a patient with suspected normal pressure hydrocephalus (NPH).The test involves removing 30mL of cerebrospinal fluid (CSF) through a lumbar puncture, after which cognitive function is clinically reassessed. Clinical improvement showed a high predictive value for subsequent success with shunting.