Previous
Differential Diagnosis
The recognition of dementia is a two-step process. Clinicians must first determine whether dementia exists or not. In order to do so, other possible disorders such as those described below must first be ruled out. Once this has occurred, specific causes of dementia can be identified [1].
Delirium
acute confusional state that develops over a short period of time
disturbance of consciousness with reduced attention span
change in cognition present i.e. memory deficit, disorientation, language disturbance
there is usually evidence of a medical cause e.g. drugs, infections, metabolic disorder and electrolytes/fluid imbalance [2]
Depression
very common in the elderly population
symptoms of weight loss or depressed mood lasting at least two weeks and a change from previous level
plus any 4 of the following: weight loss, insomnia/hypersomnia, fatigue, feelings of worthlessness/guilt, psychomotor agitation, decreased concentration, recurrent thoughts of death or suicidal ideation
may have patchy cognitive losses on testing [2]
Mild Cognitive Impairment (MCI)
impairment in memory only
all other cognitive functions are spared
preserved basic day to day functioning
no other obvious medical or psychiatric explanation for the memory problems
10-15% of patients with MCI will progress to dementia per year, particularly the amnesic type MCI [3]
_________________________________
1. Mendez MF, Cummings JL. Dementia: a clinical approach. 3rd ed. Philadelphia (PA): Elsevir Inc; 2003.
2. American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM IV) 4th edition. Washington: The Association; 1994.
3. Morris JC, Storandt M, Miller JP, McKeen DW, Price JL, Rubin EH et al. Mild cognitive impairment represents early-stage Alzheimer's Disease. Archives of Neurology 2001; 58(3): 397-405.
