initial phase of AD generally includes anterograde amnesia which lead
progressive decline in retrieval of memory of the collection of past experience
occurred at particular time and place (episodic memory). Some memory tests may
reveal deficits in formation of new memories and consolidation into long term
memories. These tests have proven that AD patient show loss of memory instantly
after a time delay and do not improve even after memory cues are given. Impaired
semantic memory and language also may be considered as early symptoms during
the progression of AD. These difficulties are supposed to result from the
degenerative disease mechanisms causing damages in the interconnected neurons
of brain involved to memorise times, places, associated emotions and other contextuals
Knopman et al. 2011).
Tests of verbal fluency may detect impairment with the tendency to perform
relatively worse on tasks which is based on generation of words from a
particular category with respect to generation of words beginning with a particular
letter of the alphabet. Poor performance can be typically observed on
confrontation naming tests and semantic categorization (Bondi,
Salmon et al. 2009; Weintraub, Wicklund et al. 2012).
Decline in executive functioning can be checked on tests of complex sequencing,
mental flexibility, problem solving and working memory. Deficits in these areas
may be detected using some tests such as the Porteus Maze task, Tower of London
puzzle, Wisconsin Card Sorting Task and Trail-Making Test. All test are useful
to check decline in performing activities of daily living (Weintraub,
Wicklund et al. 2012).
dificits in visuospatial functioning are not early features of AD, but it
deteriotes over the period of the disease progression. In particular,
visuoconstructional deficits may be observed on the Clock drawing task and on
complicated copying tasks using drawing (Lezak
2004; Malamut and Ryan 2008).
The AD patient with impaired visuoconstructional deficits tends to perform
their copy of design close to the stimulus item. Additionally, visuoperceptual
and visual orientation abilities may be become progressively disturbed with
advanced stage extrapyramidal motor signs are likely more prominent in AD
patient. Patients may suffer from impairment in ideomotor (Unconscious motor
activity) and ideational (conscious motor activity), even in the early stages
of the disease progression (Malamut
and Ryan 2008).
This causes inability to perform daily routine tasks independently (Lezak