Individuals in the second stage with moderate impairment
have more difficulty in processing  and remembering new
information. The following symptoms may present:

• Increase in memory loss, including names and places.
• Greater word-finding difficulties leading to talking around
  the subject, making up words, or withdrawing from conversations.
• Problems with following conversations and television programs.
• May become lost easily, poses possible risk to self and cannot
  safely be alone.
• May experience visual-spatial perceptual problems (Mom stopped
  reading and could not work on simple jig-saw puzzles.)
• Greater neglect of hygiene needs.
• Possible mood disturbances, behavioral outbursts and agitation.
• May exhibit paranoia.
• Possible hallucinations, auditory or visual, or both.
• Increased confusion, pacing and wandering.
• May experience urinary incontinence (Mom needed to wear disposable
  underwear because she did not get to the bathroom on time.) 

Individuals in the third or severe stage demonstrate pronounced
symptoms of   confusion and forgetfulness, endangering themselves.
The following symptoms may present:

• May not recognize family members or their own faces.
• Unable to express pain or feelings (Mom no longer told me that she
  was uncomfortable during one of those frequent urinary tract infections.)
• May need assistance with feeding, need food pureed or to be spoon fed.
• Incontinence
• Immobility may be experienced; if walking, the individual is often at
  high risk for falls.
  
• Mute or severely limited communication abilities.
  

Occupational therapists working in geriatric facilities may administer the Allen
Cognitive Levels test to measure what a person can or cannot do and understand.
This helps with predicting functional abilities and plan what care or level of
assistance is needed.  Level six indicates normal functioning and level one
corresponds to the late stage of dementia when the person demonstrates limited
response to the environment. Patients with mild decline at level five might be
referred for occupational therapy services for help with environmental adaptations
to function with limited supports; whereas individuals at level four need assistance
with complex tasks. These individuals may remember concrete tasks such as
dressing and grooming, but need to be assisted for quality. Patients at level three
and two typically require 24 hour supervision.
(http://www.carersqld.asn.au/The_Six_Cognitive_Levels.pdf)