MRCP2-3769

MRCP2-3769

A 75-year-old man presents to his GP with a history of unsteady gait. He reports a gradual deterioration in his gait over the past few months and has had multiple falls. His wife has noticed a decline in his concentration and immediate memory, as well as irritability and emotional blunting. He was initially diagnosed with depression and started on citalopram, but with little improvement. He has a medical history of benign prostatic hypertrophy and hypertension treated with bendroflumethiazide.

On examination, he appears thin and easily distractible with marked perseveration. His mini-mental state examination score is 21/30 with deficiencies in executive function and naming. Bilateral palmomental reflexes are present, but cranial nerve and upper limb examination are normal. Lower limb examination reveals a gait apraxia. Cardiovascular, respiratory, and abdominal examinations are unremarkable, but he has been incontinent of urine.

A lumbar puncture is performed, and the results are as follows: opening pressure 19 cmH2O, CSF protein 0.45 g/L (0.15-0.45), CSF white cell count 4 cells per ml (<5 cells), CSF red cell count 1 cell per ml (<5), and CSF glucose 3.5 mmol/L (3.3-4.4). What is the most likely diagnosis for this 75-year-old patient?