OVERVIEW
Persistent global cognitive impairment due to brain damage
The main manifestations are memory, executive function decline, language dysfunction, visuospatial impairment, disorientation, hallucinations, delusions, etc.
There are many causes, and most of them are neurodegenerative diseases and cerebrovascular diseases.
Drugs and rehabilitation can be used to slow down the progression of the disease.
Definition
Dementia is a clinical syndrome in which brain dysfunction is caused by a variety of reasons, resulting in severe cognitive dysfunction.
The main manifestations are decreased memory, executive ability, inattention, language dysfunction, visuospatial impairment, disorientation, and decreased ability to live.
Unlike mild cognitive impairment, cognitive impairment in dementia is not only more severe, but also involves at least two or more cognitive domains, and can be accompanied by hallucinations, delusions, hyperactivity, and other abnormalities of mental behavior. The patient’s daily or social abilities are significantly diminished.
Dementia is not a specific disease; many diseases can cause dementia, but the most common are Alzheimer’s disease and vascular dementia.
Staging and Classification
Dementia symptoms can be categorized by cause.
Neurodegenerative diseases: Alzheimer’s disease, frontotemporal lobe dementia, dementia with Lewy bodies, Parkinson’s comorbid dementia, Huntington’s disease.
Non-neurological degenerative diseases: vascular dementia, traumatic brain dementia, normal cranial pressure hydrocephalus, toxic diseases, infectious diseases, tumors, immunity, and other diseases causing dementia.
Morbidity
About 55 million people worldwide have dementia, more than 60% of whom live in low- and middle-income countries.
The incidence of dementia varies with different causes, taking the most common ones, Alzheimer’s disease and vascular dementia, as examples.
The prevalence of Alzheimer’s disease among people over 60 years of age in China ranges from 0.75% to 4.69%, and vascular dementia ranges from 1.1% to 3.0%.
Alzheimer’s disease is the most common type of dementia, accounting for 50% to 70% of all dementia, and the incidence of dementia with Lewy bodies and frontotemporal lobe dementia is second only to Alzheimer’s disease, accounting for about 10% to 20% of all dementia.
Vascular dementia accounts for 15-20% of all dementia types and is the most common non-degenerative disease dementia.
Causes
Causes
Dementia with degenerative diseases
Most of the etiology and pathogenesis are unclear and may be related to genetics, metabolism, and neurotransmitters.
Alzheimer’s disease
Genetic factors: Familial Alzheimer’s disease is thought to be an autosomal dominant disorder, and sporadic Alzheimer’s disease is associated with mutations in the apolipoprotein E (APOE) gene.
Metabolic abnormalities: Abnormal deposition of beta-amyloid in the brain and hyperphosphorylation of tau protein can lead to neuronal degeneration.
Neurotransmitter deficits: Severe decreases in acetylcholine levels in the patient’s brain are closely correlated with cognitive dysfunction.
Frontotemporal dementia.
May be associated with decreased levels of both 5-hydroxytryptamine and dopamine in the brain.
Lewy body dementia
May be associated with the formation of Lewy bodies in the neurons of the patient’s brain.
Parkinson’s dementia
Patients with Parkinson’s dementia also develop Lewy bodies and beta-amyloid in the neurons of the brain, and may be associated with damage to the synaptic and transmitter systems.
Huntington’s disease
Associated with damage and degeneration of neurons in the caudate nucleus, nucleus accumbens, and cerebral cortex.
Non-degenerative disease dementia
Associated with damage, necrosis, degeneration, and ischemia and hypoxia of nerve cells and their connections in the brain due to disease, trauma.
Vascular dementia
Such as large cerebral infarction, multiple cerebral infarctions, cerebral hemorrhage or subarachnoid hemorrhage, and atherosclerosis.
Infectious diseases
Such as viral encephalitis, AIDS, neurosyphilis, neuroleptospirosis, etc.
Metabolic or toxic encephalopathy
Such as chronic hepatic encephalopathy, uremia, anemia, CO poisoning, drug poisoning, alcohol poisoning, vitamin B12 or folic acid deficiency, etc.
Brain tumor or occupying lesion
Such as primary or metastatic brain tumor in the brain, chronic subdural hematoma, subdural effusion.
Traumatic brain injury
Including open or closed craniocerebral injury.
Risk factors
Taking Alzheimer’s disease and vascular dementia as an example, the high-risk factors causing the above diseases are as follows:
Common Risk Factors
Advanced age.
Overweight, obesity, long-term smoking, alcohol consumption.
Metabolic syndrome: hypertension, diabetes, hyperlipidemia, hyperhomocysteinemia, etc.
Individualized risk factors
Vascular dementia: underlying cardiovascular diseases such as atrial fibrillation, coronary atherosclerotic heart disease, etc.
Alzheimer’s disease: genetics, female gender, education level, traumatic brain injury.
Symptoms
Major Symptoms
Mainly include cognitive impairment, mental behavioral abnormalities and personality abnormalities.
Cognitive impairment
Memory dysfunction: difficulty remembering recent events, difficulty in learning new knowledge and things.
Executive dysfunction: Decreased ability to make decisions, organize, plan and accomplish things.
Logical Reasoning Dysfunction: decreased ability to think abstractly, slower thinking speed, decreased ability to speculate on the development of events.
Attention Deficit Disorder: inability to concentrate, decreased ability to focus on one task.
Numerical dysfunction: decreased ability to perform simple calculations, difficulty in transcribing numbers.
Language dysfunction: decreased comprehension and expression when communicating, inability to find the right words to express oneself when communicating.
Visuo-spatial dysfunction: inability to correctly perceive visuo-spatial relationships, easy to get lost.
Mental Behavioral Abnormalities
Manifested by personality changes, anxiety, depression, agitation, apathy, etc.
Fidgety, hyperactive, violent and irritable, aggressive behavior, picking up garbage, hiding things, eating without knowing whether they are hungry or full, insomnia, etc.
In severe cases, hallucinations, loss of speech, incontinence, and ultimately personal inability to care for oneself.
Personality abnormalities
Becoming suspicious, resentful, apathetic, impulsive, having all kinds of unrealistic ideas, mood swings, temperamental, etc.
Complications
Lung infection
When the disease is serious, the patient will be bedridden for a long time, unable to take care of himself, and at the same time, it is easy to lead to lung infections because the ability to swallow is affected.
Symptoms such as fever, cough and sputum are manifested.
Urinary tract infection
Urinary tract infection is mostly caused by prolonged bed rest, difficulty in cleaning the perineum and urinary incontinence.
There may be fever, cloudy urine, leukocytosis in routine urine examination.
Deep vein thrombosis
Long-term bed-ridden patients, can cause lower extremity venous thrombosis, manifested as limb swelling, local skin temperature is slightly high, and in severe cases, there can be distal limb necrosis.
Venous thrombus dislodgement can cause pulmonary embolism, dyspnea, cyanosis, cough, hemoptysis, etc., life-threatening.
Malnutrition
When severe cognitive impairment occurs, malnutrition may result from not knowing whether one is hungry or full, not being able to use utensils, and not being able to cooperate with food.
This may be manifested as pallor, muscle atrophy, limb edema, etc.
Medical treatment
Department of Medicine
Neurology
Patients with memory, concentration, thinking ability, fidgeting, moodiness and other abnormalities are advised to consult a doctor promptly.
Rehabilitation
After clarifying the cause of the disease, patients can go to the Department of Rehabilitation for cognitive function training, which can help their condition recover.
Preparation
Consultation: Registration, Preparation of documents, Frequently Asked Questions
Tips for medical treatment
Patients need to be accompanied by family members, preferably those who know the patient’s medical history, in order to provide detailed diagnostic evidence.
If the symptoms of cognitive impairment are not easy to express, you can tell the doctor some specific examples during the consultation.
Preparation List
Symptom list
Particular attention should be paid to the time of onset of symptoms, special manifestations, etc.
Do you often lose things and forget things you have promised?
Do you have slower reflexes and difficulty making decisions?
Can you remember the way home when you go out recently?
Are there any changes in personality or mood?
How long have the symptoms lasted?
Medical History Checklist
Are you suffering from hypertension, diabetes mellitus, hyperlipidemia, high homocysteine, etc.?
Any strokes, coronary heart disease, atrial fibrillation, atherosclerosis, traumatic brain injury?
Do you have Parkinson’s disease, Huntington’s disease, brain tumor, hydrocephalus?
Are you a chronic smoker, alcoholic, overweight or obese?
Has anyone in the family suffered from similar diseases, cerebrovascular disease?
Checklist
Examination results in the past six months, which can be brought to the doctor’s office
Imaging tests: cranial CT, cranial magnetic resonance imaging (MRI), positron emission tomography ((PET)), etc.
Laboratory tests: blood glucose, blood lipids, homocysteine, etc.
List of medications
Cognitive improvement drugs: donepezil, carboplatin, memantine, etc.
Medications for underlying diseases: aspirin, clopidogrel, atorvastatin, simvastatin, folic acid, etc.
Diagnosis
Diagnosis is based on
Medical history
History of stroke, coronary heart disease, atrial fibrillation, atherosclerosis, traumatic brain injury.
History of Parkinson’s disease, Huntington’s disease, brain tumor, hydrocephalus, etc.
Whether anyone in the family has suffered from similar diseases.
Clinical manifestations
Dementia is primarily judged by clinical symptoms.
Abnormalities such as decreased memory, concentration, thinking ability, fidgeting, moodiness, etc. are often present.
Laboratory Tests
Common items: blood routine, C-reactive protein analysis, biochemistry, homocysteine, vitamin B12, thyroid hormone and so on.
Purpose of examination: to assist in determining the cause of the disease, whether there is inflammation, nutrition, metabolism, endocrine abnormalities.
Precautions: Regular monitoring may be required during the course of treatment.
Imaging examination
Magnetic resonance imaging (MRI) of the head
Vascular dementia can show the location, size, and number of brain atrophy, brain softening foci, and brain white matter lesions.
Alzheimer’s disease may show cerebral atrophy, with cerebral atrophic changes mainly in the temporal lobe and hippocampus.
Precautions
You cannot bring any metal objects into the examination room, including cell phones, keys, necklaces, earrings, watches, and steel rings from underwear.
Those who have dentures or metal implants in the body, such as heart stents, etc., need to inform the radiologist, who will determine whether the MRI examination can be performed.
Positron Emission Tomography (PET)
PET can evaluate the oxygen content and glucose metabolism of brain tissue, which is significant for early diagnosis of dementia.
It may reveal localized decreased metabolic levels in the parietal, temporal, and frontal lobes.
Precautions
Fasting for 6 hours before the test is usually required to avoid taking foods high in sugar.
Drink as much water as possible after the examination to promote the elimination of contrast agent metabolism.
Neuropsychological Assessment
The most commonly used assessment scales are the Montreal Cognitive Assessment Scale (MoCA), and the Brief Mental Status Examination (MMSE).
Decreased abilities in attention, executive function, memory, language, and visuospatial function may be present.
Cautions
The score that determines the presence of cognitive impairment (measurement threshold) is related to the educational level of the test subject. The more years of education, the higher the threshold.
The use and interpretation of the Cognitive Assessment Scale requires a combination of clinical manifestations, and self-testing is not recommended.
Cerebrospinal fluid examination
To clarify the presence of infection, inflammation, and antibodies in the skull, and is helpful in the diagnosis of certain inherited metabolic diseases.
It is an invasive test, and a mild headache may occur after the test. It is necessary to lie down and drink plenty of water.
Genetic testing
If dementia is considered to be caused by genetic factors, genetic testing needs to be improved.
The genetic characteristics can be clarified, and the type of mutation can guide the use of medication, assess the prognosis, and evaluate the possibility of passing the mutation to the offspring, guiding eugenics.
Caveat: Genetic testing is not currently used as a routine etiologic screen and is usually performed when there is a high degree of suspicion for a particular disease.
Differential Diagnosis
Dementia, as a common symptom of many diseases, requires primarily a differential between etiologies.
Disease History Symptoms Ancillary Tests
Alzheimer’s disease without cerebrovascular disease history of memory loss as the main early manifestations of cranial MRI may appear hippocampal and medial temporal lobe atrophy, no cerebral ischemic foci, hemorrhagic foci and other local manifestations
Alzheimer’s disease
No history of cerebrovascular disease
Memory loss is the main early manifestation
Hippocampal and medial temporal lobe atrophy on cranial MRI without localized manifestations such as ischemic or hemorrhagic foci.
Vascular dementia without history of cerebrovascular disease, impaired executive function, often accompanied by hemiparesis, sensory deficits and other neurological injuries Cranial MRI may show cerebral ischemic foci, hemorrhagic foci, etc.
Vascular dementia
No history of cerebrovascular disease
Impaired executive function, often accompanied by hemiparesis, sensory deficits and other neurological injuries.
Cranial MRI may show cerebral ischemic foci, hemorrhagic foci, etc.
Parkinson’s disease dementia with a history of Parkinson’s disease, cognitive deficits appear after typical Parkinson’s symptoms such as resting tremor, bradykinesia, etc., and the impairment of executive function is more obvious, and there is no special abnormality in cranial MRI.
Parkinson’s disease dementia
History of Parkinson’s disease
Cognitive deficits occur after typical Parkinson’s symptoms such as resting tremor, bradykinesia, etc., and executive function impairment is more pronounced
No specific findings on MRI of the skull
Treatment
Aim of treatment: to control the recurrence and progression of the underlying disease, to relieve symptoms, and to slow down the progression of the disease.
Treatment principle: there is no specific treatment for dementia, drug treatment is the mainstay, together with rehabilitation training.
Medication
Due to the many causes of the disease, the following drugs can be used to alleviate the degeneration of brain function, improve the symptoms of dementia and slow down the progress of the disease while treating the causes of the disease.
Excitatory amino acid receptor antagonist
Purpose of medication: It can prevent the excessive release of excitatory amino acids, slowing down or preventing neurodegenerative diseases.
Representative drug: memantine.
Precautions
Should be used with caution in patients with epilepsy and a history of convulsions.
Should not be combined with amantadine, dextromethorphan and other drugs.
Cholinesterase inhibitors
Purpose: Cholinesterase inhibitors can reduce the breakdown of the neurotransmitter acetylcholine, so that its content increases, delaying the degenerative neuronal disease, and thus improve cognitive function.
Typical drugs: Donepezil, Carboplatin, Galantamine.
Precautions
Adverse reactions such as diarrhea, nausea and headache may occur after taking the drug.
Start with a low dose initially and gradually increase the dose to build up tolerance.
Drugs to control mental and emotional symptoms
Purpose of medication: Relief of symptoms such as depression, anxiety, agitation, apathy, etc.
Antidepressants: Mostly choose pentazocine reuptake inhibitor (SSRI) drugs, such as fluoxetine, paroxetine, citalopram, sertraline, etc.
Antipsychotics: risperidone, olanzapine, quetiapine, etc.
Other drugs
Butylphthalide: improve blood circulation in the brain, improve the anti-ischemic effect of brain tissue, improve energy metabolism in ischemic brain area.
Olacetamol: enhance the release of excitatory neurotransmitters, improve cognitive impairment.
Rehabilitation therapy
Rehabilitation therapy helps to slow down the progression of dementia and improve the quality of life of patients.
Cognitive function is a prerequisite for other rehabilitation training. For those with severe dementia who have difficulty in cooperating with training, the effectiveness and value of rehabilitation training should be assessed in advance.
Cognitive training
Individualized thinking, memory, calculation and orientation training with the assistance of a therapist or computer to improve the patient’s emotional, behavioral and cognitive conditions.
The format can be “one-on-one” or multi-person group training.
Memory, calculation and thinking skills are trained through memorizing numbers, doing math problems and reasoning problems.
Motor Function Training
Turning over, getting up, standing up, walking, cardiorespiratory training (e.g., rehabilitation bicycle, power bicycle), etc., under the assistance and guidance of the therapist.
Exercise training is not only suitable for patients with combined physical dysfunction, but is also an important method to improve cognitive function.
Speech and phonological training
Train patients to respond correctly from listening, speaking, reading, writing, and pharyngeal muscle movement to improve speech function.
Repetitive Transcranial Magnetic Stimulation (TMS)
A non-invasive magnetic stimulation that acts directly on the nerves of the brain.
Used to improve cognitive function and mental behavioral abnormalities such as apathy, depression and agitation.
Psychological, psychiatric treatment
Mainly used to control patients’ mental and behavioral symptoms.
Methods for patients include reminiscence therapy (discussing past experiences), recognition therapy (resolving past conflicts), and music therapy.
Train and support caregivers to develop individualized treatment strategies that take into account the patient’s interests, cognition, and physical strength.
Avoid over- or under-stimulation, e.g., crowds and noises, stimulating colors, lack of interaction, etc., and eliminate safety hazards.
Chinese medicine treatment
Some Chinese medicines, proprietary Chinese medicines and acupuncture treatments are complementary to dementia patients and need to be carried out under the guidance of specialized doctors.
Classical prescriptions: tonifying Yang and restoring the five tangs, dihuang drink, angelica and peony powder, six flavors of dihuang pill, blood-fu chasing blood stasis soup, tianma and hooker drink.
Proprietary Chinese medicines: e.g. Yishen Nourishing Brain, Xinguangtong, Tongxinluo, Yizhi Zengshou Pill.
Acupuncture and moxibustion treatment: often take Si Cong point, Bai Hui point, Feng Long, Foot San Li, Xin Yu, Kidney Yu and other points.
Prognosis
Cure
The prognosis of patients with dementia is closely related to the cause of the disease, but dementia symptoms usually have already occurred a large number of nerve cell damage, symptoms fluctuate for a short period of time, but the condition will gradually worsen, and can not be cured.
Most patients with Alzheimer’s disease have a disease duration of 5 to 10 years, and some patients may survive for 10 years or longer, mostly dying from complications such as lung infections, urinary tract infections and pressure sores.
The average survival of patients with vascular dementia is 8 to 10 years, with most deaths occurring in the later stages due to pulmonary infections and cardiovascular disease.
Prognostic factors
The prognosis is mainly related to the following factors:
Age of onset.
Site and extent of brain tissue damage.
Control of underlying disease.
Complications.
Hazardous nature of the injury
Decrease in daily life ability
Decrease in self-care and socialization ability due to severe cognitive dysfunction, which seriously affects the quality of life.
Presence of incontinence, day and night reversals, agitation, and increased caregiver burden.
Accidents
Patients may suffer from accidents such as wandering, falling, burns, scalds, gas poisoning, drug poisoning and so on.
Daily routine
Daily management
Dietary management
Patients who can eat normally
Patients with Alzheimer’s disease are recommended to follow the Mediterranean dietary pattern (vegetables and fruits, fish, grains and cereals, legumes and olive oil mainly).
Patients with vascular dementia should follow a low-salt, low-fat and low-sugar diet.
For other patients, a balanced diet is recommended.
When there is difficulty in swallowing and inability to eat voluntarily
Puree food or use enteral nutrition to supplement nutrition through nasal feeding tube.
Life management
Regular work and rest, ensure sufficient sleep time, do not smoke, do not drink alcohol.
Create a quiet and comfortable living environment and avoid exposing the patient to excessive stimuli, such as noise, crowds and noises.
For overweight or obese people, keep their weight within the standard range.
For patients with incontinence, put a plastic sheet on the bed, or use adult diapers, but be careful to change them in time and wash the perineal area.
Management for cognitive impairment
Help with memory through journals, calendars, etc.
Secure everyday items such as keys, wallet, cell phone, etc. in the same place in the house.
Keep medications in a safe place and use a daily checklist to record doses.
To prevent getting lost, carry a note with your home address and family contact numbers.
Keep items that pose a safety hazard, such as knives and scissors, in a safe place.
Psychological support
Family members should provide more encouragement and comfort to the patient, build up confidence in treating the disease, and create a calm and comfortable environment for him/her to alleviate the effects of adverse emotions.
Assistance from professional psychological practitioners can be sought if necessary.
Disease monitoring
Monitor blood pressure, blood glucose, weight, etc. to control the underlying disease.