Are All Dementias Alzheimer’s?

I’m surprised when some patients and caregivers confuse dementia and Alzheimer’s as one and the same. Each time a family member is suffering from memory loss, the conclusion is always Alzheimer’s. Is it reasonable to label all dementias as Alzheimer’s?

As a clinician, my answer to queries is that Alzheimer’s dementia is only one type of dementia and that not all dementias are Alzheimer’s. Aside from Alzheimer’s disease, other dementias exist such as Dementia with lewy body, Vascular dementia, Parkinson’s disease with dementia, and dementias due to various neurologic and medical conditions.

How will you know if a person is suffering from Alzheimer’s dementia? What is Alzheimer’s dementia?

Alzheimer’s dementia is a neurologic disorder characterized by a progressive and irreversible cognitive decline associated with impairment in functioning. The cognitive deterioration consists of memory impairment. Initially there is recent memory impairment but as the disease progresses, even the long term memory is affected.

In addition to memory impairment, a patient with dementia has impairment in one of four cognitive areas: aphasia, apraxia, agnosia, and impairment in executive functioning. Aphasia is a problem in language characterized by inability to express oneself, repeat words or phrases, or understand what is being said. Apraxia is inability to adequately perform a usual motor activity such as combing the hair or brushing the teeth despite no paralysis or musculoskeletal abnormality.

Agnosia is inability to recognize objects or things despite intact sensory functions. For instance, a demented patient cannot recognize a key or a pen placed in his or her hands without looking at it.

Impairment in executive functioning is characterized by difficulty in abstract reasoning and in organizing things, schedule, and activities. Patients with this problem give concrete meaning to proverbs. For example, when a patient is asked what “don’t cry over spilled milk” means, the patient responds, “It’s easy. Just wipe it!” Moreover, knowing the specific similarities and differences of certain things (e.g. apple versus orange) is a struggle for some patients.

What are the possible causes of Alzheimer’s?

The cause of Alzheimer is still unknown. However, several risk factors have been identified. One major risk factor is age. The risk of developing dementia increases as our age advances. Older individuals therefore are more at risk. Having said this, Alzheimer’s can also happen to young individuals.

Other important risk factors include the presence of apolipoprotein E4 allele, the predominance of plaques and tangles in the brain, and the brain’s impaired cholinergic system.

Is there any successful treatment for Alzheimer’s?

Alzheimer’s disease is irreversible so current medications are only geared to slow down the deterioration. These acetylcholisterase inhibitors, namely galantamine, rivastigmine, and donepezil, are aimed at improving the cholinergic functioning in the brain by inhibiting the cholinesterase enzyme. Although initially indicated for mild to moderate dementia, some recent evidence shows that some of these drugs may also benefit patients with moderate to severe dementia. Further studies are warranted to determine its efficacy in this group.