> The prevalence rates of hallucinations in Alzheimer's disease (AD) range from 12 to 53%. Hallucinations in AD most often are visual, although auditory, tactile and olfactory hallucinations have also been observed. Hallucinations are most prevalent in the moderate to severe stages of the illness and do not seem to occur at the end stage of the disorder.
> The spider-like hallucinations are classic alcohol-withdrawl symptoms not directly associated with dementia or alzheimer's.
You said "not directly associated with alzheimer's".
That's incorrect. Some, but not most, people with alzheimer's experience tactile hallucinations.
Here's another cite:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3105559/
> Alzheimer's disease
> The prevalence rates of hallucinations in Alzheimer's disease (AD) range from 12 to 53%. Hallucinations in AD most often are visual, although auditory, tactile and olfactory hallucinations have also been observed. Hallucinations are most prevalent in the moderate to severe stages of the illness and do not seem to occur at the end stage of the disorder.