Definition
A.A major neurocognitive disorder in which the patient exhibits a significant cognitive decline in one or more of the areas described in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5).
1.Complex attention.
2.Executive function.
3.Language.
4.Learning and memory.
5.Perceptual-motor function.
6.Social cognition.
B.The DSM-5 also states the impairment should be acquired and a decline from the patient’s normal functioning, inhibit independence and activities of daily living (ADLs), and not be occurring during bouts of delirium or as a function of another mental condition (e.g., depression or schizophrenia).
C.Alzheimer’s disease (AD) accounts for most cases of dementia. While the term is often used interchangeably with dementia, AD only represents a single subtype of neurodegenerative dementia. Neurodegenerative dementias are progressive and exhibit an insidious onset.
Incidence
A.Age: Typically over the age of 65; however, early onset dementia accounts for 40 to 100 cases per 100,000 people in the developed world.
B.Incidence: Alzheimer’s dementia affects more than 5 million individuals over the age of 65, accounting for 80% of dementia cases, with vascular dementia second.
Pathogenesis
A.Dementia can be influenced by multiple pathologies and is disease specific.
B.Types of dementia and selected pathophysiology.
1.Neurodegenerative (Alzheimer’s, dementia with Lewy bodies, Parkinson’s disease).
2.Vascular diseases (vascular, cerebral amyloid angiopathy, and angitis).
3.Infectious diseases (prion disease such as Creutzfeldt–Jakob disease [CJD; mad cow], herpes encephalitis, neurosyphilis).
4.Inflammatory and autoimmune (multiple sclerosis, para- and nonparaneoplastic, autoimmune diseases).
5.Neurometabolic disorders.
6.Other (traumatic encephalopathy, alcohol abuse, Wilson and Huntington diseases).
a.Genetic.
b.Malnutrition.
Predisposing Factors
A.Age (frequency increases with age).
B.Positive family history.
C.Female (could be related to life span).
D.History of head trauma or cerebrovascular accident (CVA).
E.Low education level.
F.Environmental factors: Aluminum, mercury, and viruses.
G.Physical condition and other medical factors (e.g., diabetes, hypertension, and hypercholesterolemia).
Subjective Data
A.Common complaints/symptoms.
1.While memory is a problem, it is usually not mentioned by the patient, but by the significant other or family.
2.Frequently cannot pinpoint the condition’s onset; years may have passed with problems, but until a major change happens, such as needing to stop driving or a hospital admission, the patient may be mostly functional in his or her familiar environment.
3.Signs and symptoms.
a.Difficulty maintaining new information or task.
b.Inability to manage complex task like balancing a checkbook.
c.Lapses in reasoning.
d.Becoming lost in familiar places.
e.Word finding issues.
f.Changes in behavior.
B.Common/typical scenario.
1.Patients typically start with subtle short-term memory changes, frequent forgetfulness, difficulty finding the right words, or difficulty completing tasks.
2.The patient may progress over months and years before coming to a provider.
C.Family and social history.
1.Family history and first degree relatives may be important in AD.
2.Obesity and chronic sedentary lifestyle may increase risk.
3.Smoking, alcohol, and drug abuse increase risk of dementia.
D.Review of systems.
1.Neurological: Ask about memory and any confusion or deficits in calculation and abstraction.
2.Psychological: Ask about depressed mood, hopelessness, or suicide tendencies or changes in personality.
3.Inquire about rate of onset of changes.
4.History from a reliable source including medications.
Physical Examination
A.Assessment and physical examination change with the type of dementia present. Motor, somatosensory, and visual functions may remain intact until later in the disease process.
1.Disorder of motion.
2.Eye movement.
3.Primary memory.
4.Performance on cognitive assessments.
Diagnostic Tests
A.Cognitive function.
1.Mini-Mental state examination (max score 30; less than 24 indicates possible dementia).
a.Concentration.
b.Language.
c.Orientation.
d.Memory.
e.Attention.
2.Montreal cognitive assessment (max score 30; lower than 25 indicates possible dementia).
3.Clinical dementia rating (includes a caregiver).
4.Mini-Cog (clock draw and recall test).
5.Informant interview to ask caregivers about the patient’s functioning.
a.Issues with judgment.
b.Lack of interest in usual activities.
c.Repetition of questions, statements, stories.
d.Difficulty learning new tools or household appliances.
e.Inability to remember the month or year.
f.Loss of ability to manage finances.
g.Missing appointments.
h.Persistent issues with thinking or memory.
B.Physical examination.
1.Full neurological examination.
2.General physical examination to identify any medical illness that could account for deficits.
3.Motor examination to identify prior stroke or evidence of Parkinson disease or autoimmune issues.
4.Evaluation of sleeping habits.
C.Lab studies (*as recommended by the American Academy of Neurology).
1.Screen for B12 deficiency*.
2.Hypothyroidism*.
3.Rapid plasma reagin (RPR) screening*.
4.Complete blood count (CBC).
5.Comprehensive metabolic panel (CMP).
6.LFT.
7.Immune/autoimmune workup.
8.Cerebrospinal fluid (CSF) analysis if infective cause is suspected.
D.Imaging: Neuroimaging (as recommended by the American Academy of Neurology) including CT or MRI and possibly electrophysiologic testing.
E.Brain biopsy not recommended unless in vasculitis, cancers, or infection.
F.Genetic testing is not recommended except for specific diseases in family history (e.g., Huntington disease).
Differential Diagnosis
A.Treatable: Thyroid, vitamin deficiencies, tumor, drug and medication intoxication, chronic infection, and severe depression. Once these are ruled out, the differential is among the types of dementia.
B.Structural: Cortical and hippocampus atrophy leads to AD.
C.Psychiatric history with pharmacological treatment may be drug related.
D.Associated: Gait disturbances could be vascular or Lewy body, including Parkinson, which may be based on time of onset.
E.Rapid onset could be CJD or frontotemporal dementia.
F.For early onset (under the age of 65): There is a much broader list of differentials and requires more extensive testing.
Evaluation and Management Plan
A.General plan.
1.Includes finding and correcting any reversible causes.
a.Vitamin or thyroid replacements.
b.Stopping contributing medications or starting medications for contributing conditions such as depression.
c.Treating any structural dysfunction such as neoplasms or increased intracranial pressure.
d.Treating any infections contributing to mental status.
2.When no correctable cause is found, supportive care for the patient and the caregiver is warranted.
3.Diet.
a.Patients with dementia often have decreased appetite for a variety of reasons.
b.When possible, provide food to support adequate nutrition.
c.Supplement any deficiencies.
d.Adequate overall intake may be preferred over following a strict low cholesterol/glucose/fat/sodium diet.
4.Other therapies/considerations.
a.Provide utmost safety for the patient and caregivers while maintaining some form of independence for the patient.
b.Modify environment.
c.Maintain a routine.
d.Treat occult conditions that could contribute to behavioral problems (like toothache or constipation).
e.Provide simple physical activities.
f.Provide caregiver respite as needed.
B.Patient/family teaching points.
1.Patient teaching is more geared toward the caregiver.
2.Many changes must be made in the patient’s life, including relinquishing some independence for the sake of safety.
3.When considering activities such as driving, safety for both the patient and public should be considered.
C.Pharmacotherapy.
1.Food and Drug Administration (FDA) approved for AD: Cholinesterase inhibitors.
a.Donepezil.
b.Rivastigmine.
c.Galantamine.