Answer

This is a difficult question to answer because the two conditions do have things in common.

But from what you say I would have thought Parkinson's disease was more likely.

Parkinson’s disease is a syndrome of tremor, rigidity and akinesis. The tremor especially affects the wrists and digits causing a characteristic 'pill-rolling' tremor, most marked at rest.

The limbs are rigid and resist movement and when combined with the tremor give a so-called 'cogwheel' feeling, when the hand is turned during a handshake.

Akinesis is slowness in initiating and executing movements and causes small writing, taking small paces (shuffling is characteristic), monotonous speech and lack of expression on the face.

All these symptoms are caused by a lack of the neurotransmitter dopamine with symptoms usually starting in the late 50s and that could progress to a dementia picture – hence the confusion at times.

In Alzheimer's disease the key features are a worsening of memory and general deterioration in intellect without any impairment of consciousness.

Alzheimer's is still not readily treatable but Parkinson's can be – in the early stages at least.

It's important you discuss the changes you've seen in your father with the specialist since these observations are often the key to the diagnosis, having occurred over many months.

Yours sincerely