Alzheimers Dementia
DEMENTIA
Dementia is a neurological illness of mostly an aging population affecting memory and other cognitive domains leading to poor functioning at a social or occupational level. When mild and subjective the term mild cognitive impairment (MCI) is used by physicians. Though there are many causes of dementia the most common cause is Alzheimers Dementia (AD) accounting for almost 60-80 % of all dementia cases. The other causes will be listed below with key features helping their differentiation from AD.
Alzheimers dementia (AD) is named after Dr. Alois Alzheimer who first described this ailment in a patient with memory problems and psychological disturbances. Though anxiety regarding memory problems, short term memory loss (amnesia), difficulty remembering words (aphasia), poor facial recognition (agnosia) and difficulty carrying out previous known tasks (apraxia) are considered key features these are sometimes less apparent. However repetitive questioning, frequent forgetfulness, lack of interest, difficulty managing finances, misplacing objects and forgetting appointments, driving difficulties and social withdrawal are more noticeable features. Most alzheimers patients are socially appropriate and frequently resort to excuses to cover their memory lapses.
Mild, moderate and severe stages of dementia are ascertained by the ability to perform routines activities of daily living and a simple bedside test known as the mini mental status exam (MMSE) with scores from 0-30.(normal 28-30, mild dementia 15-27, moderate dementia 10-14 and severe dementia <9). The MMSE tests and other diagnostic tests will be detailed below.
Alzheimers dementia occurs due to the build of Abeta 42 amyloid proteins or plaques and neurofibrillary tangles made of Tau protein in the brain cells. This abnormal build up leads to neuronal cell loss contributing to the symptoms. AD has a hereditary component however all the genes implicated have not been deciphered and though gene testing is available it is often not covered by insurance. The genes well known to be associated with Alzheimers dementia include presenilin 1 and presenilin 2, amyloid precursor protein (APP) and finally Apo E (Apo E4 two copies or alleles of this gene increases the chance of the disease while two copies of ApoE2 decreases the chance).
Diagnosis is made by physicians experienced in the diagnosis of dementia and preferably by neurologists (click here for neurologists in the area). After a thorough history of symptoms and the course of illness is obtained a mini mental exam as well as a neurologic exam helps assess memory and other brain function impairments. Other diagnoses must be excluded and various tests may need to be performed to establish the cause. Tests including the below are commonly performed.
Lab testing for Vitamin B12 deficiency, low thyroid hormones, liver and kidney function testing with chemistry panels, and neurosyphilis are routinely performed.
Brain imaging including a CT scan brain or MRI brain with contrast is performed to establish any other etiologies (brain tumors, strokes, infections, autoimmune diseases, MS, Normal Pressure hydrocephalus to name a few that have imaging abnormalities) and to assess certain patterns of atrophy ( that help distinguish AD from Frontotemporal Dementia, primary progressive aphasia, etc.)
Electroencephalogram (EEG) to assess any underlying seizure disorder contributing to memory loss, or slow brain infections (Creutzfeld Jakob disease CJD, measles related infections, etc) or other causes of memory impairment (including encephalopathy due to abnormal liver or kidney functions .)
Neuropsychological testing when referred by neurology (usually a 4hour battery of memory testing) performed by qualified psychologists (not MDs or neurologists or neurophysiologists, but have PhD in neuro-psychological testing, and not always covered by insurance) can help differentiate difficult cases. (click here for neuro-psychologists in the area).
In addition latest functional brain imaging is available including Positron Emission Tomography or PET scans with various ligands or radiotracers including:
PET with Amyvid (Florbetapir is used to tag and detect the amyloid plaque burden) , FDG PET (flourodeoxy glucose is used to tag the brain metabolism and should show parietal and temporal lobe decreased uptake to confirm AD ), PET with Pittsburg compound B (PIB) can help diagnose AD with a high degree (>90% chance eg:- for Amyvid PET) of certainty and reliably exclude AD in those with other forms of dementia.
Finally spinal taps for research based studies can help measure the level of Abeta 42 and tau protein in the cerebrospinal fluid (CSF) encircling the brain and help confirm the diagnosis when the abeta 42 protein is decreased and tau protein is increased in CSF.
Once other causes (given below) are excluded treatment options below can be considered.
Treatment of Alzheimers dementia is limited to several medications. The most commonly used medications include a group of cholinesterase inhibitors which increase the level of acetylcholine in the brain tissue allowing for transmission of brain signals. Aricept ( Donepezil), Exelon ( Rivastigmine), and Razadyne ( Galantamine) all have been shown to improve memory marginally in those with AD. Main side effects include nausea, cramping, diarrhea and rarely lightheadedness.
Namenda ( Memantine) is an NMDA receptor antagonist which helps decrease excitatory receptor mediated cell injury and is FDA approved for moderate AD. Well tolerated it has been shown to help in agitation and behavioral issues in advanced AD patients.
Folic acid 1mg a day has been shown to be helpful in slowing the decline in small studies.
In addition a Mediterranean diet ( rich in fish, fruit and vegetables) and moderate physical exercise or activity has been shown to be protective and slows the progression of the dementia and should be a lifestyle change adopted by patients.
Other causes of Dementia:
As outlined above, various tests help exclude the other causes of dementia including labs to exclude endocrine causes (hypothyroidism), vitamin B12 deficiency, neurosyphilis, HIV related dementia, and rarely in suspected cases, infectious causes such as Creutzfeld Jakob disease (a prion disease –better known as ‘mad cow’ disease), subacute sclerosing pan encephalitis (delayed measles infection related reactions).
Other causes of dementia can be excluded by brain imaging including :
Normal Pressure Hydrocephalus (NPH) which usually presents with dementia, urinary incontinence and shuffling gait. Imaging characteristically shows enlarged ventricles. A large volume spinal tap is sometimes performed to assess improvement in memory and gait function to assess if a shunt will be helpful.
Frontotemporal dementia (FTD) is a group of dementia subtypes with frontotemporal atrophy seen on brain imaging – associated with behavioral abnormalities, disinhibition, speech problems, gait shuffling and incontinence. A form of FTD known as Primary progressive aphasia has prominent left temporal lobe atrophy on imaging and therefore predominantly presents with speech arrest, hesitancy, and difficulty finding words.
Imaging also helps to excludes Multiple sclerosis, brain tumors, brain infections, and strokes that may all be prominent causes of dementia.
Vascular dementia which presents in a step wise fashion is diagnosed if there are many small or large strokes noted on imaging and the decline in function correlates with strokes. Vascular dementia can be treated by treating underlying stroke risk factors, correcting hypertension, diabetes, hyperlipidemia and with the use of aspirin or other antiplatelet agents, cholesterol lowering medications known as statins and memory may improve with the use of the above cholinesterase inhibitors used in Alzheimers disease.
Other rare causes of dementia can be excluded by a thorough clinical exam such as parkinsons disease related dementia( with tremor, slowness), lewy body disease dementia with hallucinations and slowness, huntingtons disease with dance like involuntary movements or chorea. Alcohol abuse and multiple head injuries can also contribute to early dementia. Finally depression can mimic dementia and is appropriately termed a pseudodementia and can be excluded up by obtaining an appropriate history.
Tips for dementia:
Exercise regularly and daily with moderate physical activity
Adopt a healthy diet of fish, vegetables and fruit (a Mediterranean diet)
Take Folic Acid 1mg supplements daily
Herbal remedies such as gingko biloba have not been shown in studies to improve memory, therefore instead taking a multivitamin tablet may be more helpful.
Maintaining social contact is important for awareness
Mind exercise with games including bridge, card games, board games help stimulate memory pathways.
Reading helps maintain vocabulary and comprehension
Watching the news and other TV shows keeps one engaged and maintains awareness.
Outdoor activities, family gatherings and an active lifestyle with hobbies help keep up motivation and interest.
Detect and treat any underlying depression
Follow up regularly with your neurologist to adjust medications. Follow with the geriatric psychiatrist to adjust any medications needed to help agitation and behavioral disturbances.
Avoid change of environment as this can be disconcerting for dementia patients.
Adopt scheduled visits to the restroom to avoid pampers and help avoid infections.
Finally caregivers themselves need to reach out to others to help them occasionally for allowing breaks to recharge their own energy. They may reach out to respite care, and other care giver associations. Helpful organizations are listed below.
www.alzheimers.org ( 1-800-438-4380) for education and referrals.
www.alz.org (1-800-272-3900) Alzheimer’s Association for local resources.
www.eldercare.gov (1-800-677-1116) Eldercare locator for help caring for loved ones with AD.
PRINT PDF