Although cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes, and smoking, are associated with a higher risk of onset and course of AD, statins, which are cholesterol lowering drugs, have not been effective in preventing or improving the course of the disease.

Long-term usage of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with a reduced likelihood of developing AD. Evidence also supports the notion that NSAIDs can reduce inflammation related to amyloid plaques. No prevention trial has been completed. They do not appear to be useful as a treatment. Hormone replacement therapy in menopause, although previously used, may increase the risk of dementia.

There is no cure for Alzheimer's disease; available treatments offer relatively small symptomatic benefit but remain palliative in nature. Current treatments can be divided into pharmaceutical, psychosocial and caregiving.

Binswanger's disease has no cure and has been shown to be the most severe impairment of all of the vascular dementias. The best way to manage the vascular risk factors that contribute to poor perfusion in the brain is to treat the cause, such as chronic hypertension or diabetes. It has been shown that current Alzheimer’s medication, donepezil (trade name Aricept), may help Binswanger’s Disease patients as well . Donepezil increases the acetylcholine in the brain through a choline esterase inhibitor which deactivates the enzyme that breaks down acetylcholine. Alzheimer as well as Binswanger patients have low levels of acetylcholine and this helps to restore the normal levels of neurotransmitters in the brain. This drug may improve memory, awareness, and the ability to function. If no medical interception of the disease is performed then the disease will continue to worsen as the patient ages due to the continuing atrophy of the white matter from whatever was its original cause.

Early-onset Alzheimer's disease, also called early-onset Alzheimer's, or early-onset AD, is Alzheimer's disease diagnosed before the age of 65. It is an uncommon form of Alzheimer's, accounting for only 5-10% of all Alzheimer's cases. Approximately 13% of the cases of early-onset Alzheimer's are familial Alzheimer's disease, where a genetic predisposition leads to the disease. The other incidences of early onset Alzheimer's, however, share the same traits as the 'late onset' form of Alzheimer's disease, and little is understood about how it starts.

Non-familial early onset Alzheimer's can develop in people who are in their thirties or forties, but that is extremely rare. The majority of people with early-onset Alzheimer's are in their fifties or early sixties.

Pick's disease is a term that can be used in two different ways. It has traditionally been used as a term for a group of neurodegenerative diseases with symptoms attributable to frontal and temporal lobe dysfunction. Common symptoms that are noticed early are personality and emotional changes, as well as deterioration of language. This condition is now more commonly called frontotemporal dementia by professionals, and the use of "Pick's disease" as a clinical diagnosis has fallen out of fashion. The second use of the term (and the one now used among professionals) is to mean a specific pathology that is one of the causes of frontotemporal lobar degeneration. These two uses have previously led to confusion among professionals and patients and so its use should be restricted to the specific pathological subtype described below. It is also known as Pick disease and PiD (not to be confused with pelvic inflammatory disease (PID) or Parkinson's disease (PD)). A defining characteristic of the disease is build-up of tau proteins in neurons, accumulating into silver-staining, spherical aggregations known as "Pick bodies".

The symptoms of the disease as a distinct nosologic entity were first identified by Emil Kraepelin, and the characteristic neuropathology was first observed by Alois Alzheimer in 1906. In this sense, the disease was co-discovered by Kraepelin and Alzheimer, who worked in Kraepelin's laboratory. Because of the overwhelming importance Kraepelin attached to finding the neuropathological basis of psychiatric disorders, Kraepelin made the decision that the disease would bear Alzheimer's name.

Binswanger's disease, also known as subcortical leukoencephalopathy, is a form of small vessel vascular dementia caused by damage to the white brain matter. White matter atrophy can be caused by many circumstances including chronic hypertension as well as old age. This disease is characterized by loss of memory and intellectual function and by changes in mood. These changes encompass what are known as executive functions of the brain. It usually presents between 54 and 66 years of age, and the first symptoms are usually mental deterioration or stroke.

It was described by Otto Binswanger in 1894, and Alois Alzheimer first used the phrase "Binswanger's disease" in 1902. However, Olszewski is credited with much of the modern-day investigation of this disease which began in 1962.

The Huntington's disease-like syndromes (often abbreviated as HD-like or "HDL" syndromes) are a family of inherited neurodegenerative diseases that closely resemble Huntington's disease (HD) in that they typically produce a combination of chorea, cognitive decline or dementia and behavioural or psychiatric problems.

Neurodegeneration is the progressive loss of structure or function of neurons, including death of neurons. Many neurodegenerative diseases – including amyotrophic lateral sclerosis, Parkinson's, Alzheimer's, and Huntington's – occur as a result of neurodegenerative processes. Such diseases are incurable, resulting in progressive degeneration and/or death of neuron cells. As research progresses, many similarities appear that relate these diseases to one another on a sub-cellular level. Discovering these similarities offers hope for therapeutic advances that could ameliorate many diseases simultaneously. There are many parallels between different neurodegenerative disorders including atypical protein assemblies as well as induced cell death. Neurodegeneration can be found in many different levels of neuronal circuitry ranging from molecular to systemic.

The process of neurodegeneration is not well understood, so the diseases that stem from it have, as yet, no cures. In the search for effective treatments (as opposed to palliative care), investigators employ animal models of disease to test potential therapeutic agents. Model organisms provide an inexpensive and relatively quick means to perform two main functions: target identification and target validation. Together, these help show the value of any specific therapeutic strategies and drugs when attempting to ameliorate disease severity. An example is the drug Dimebon (Medivation). This drug is in phase III clinical trials for use in Alzheimer's disease, and also recently finished phase II clinical trials for use in Huntington's disease. In March 2010, the results of a clinical trial phase III were released; the investigational Alzheimer's disease drug Dimebon failed in the pivotal CONNECTION trial of patients with mild-to-moderate disease. With CONCERT, the remaining Pfizer and Medivation Phase III trial for Dimebon (latrepirdine) in Alzheimer's disease failed in 2012, effectively ending the development in this indication.

In another experiment using a rat model of Alzheimer's disease, it was demonstrated that systemic administration of hypothalamic proline-rich peptide (PRP)-1 offers neuroprotective effects and can prevent neurodegeneration in hippocampus amyloid-beta 25–35. This suggests that there could be therapeutic value to PRP-1.

Protein degradation offers therapeutic options both in preventing the synthesis and degradation of irregular proteins. There is also interest in upregulating autophagy to help clear protein aggregates implicated in neurodegeneration. Both of these options involve very complex pathways that we are only beginning to understand.

The goal of immunotherapy is to enhance aspects of the immune system. Both active and passive vaccinations have been proposed for Alzheimer's disease and other conditions, however more research must be done to prove safety and efficacy in humans.

The symptoms of Pick's disease include difficulty in language and thinking, efforts to dissociate from family, behavioral changes, unwarranted anxiety, irrational fears, CBD (Compulsive buying disorder, or oniomania), impaired regulation of social conduct (e.g., breaches of etiquette, vulgar language, tactlessness, , misperception), passivity, low motivation (aboulia), inertia, over-activity, pacing and wandering. It is a characteristic of Pick’s disease that dysfunctional, argumentative, or hostile social conduct is initially exhibited towards family members and not initially exhibited in a workplace or neutral environment. The changes in personality allow doctors to distinguish between Pick's disease and Alzheimer's disease. Pick's disease is one of the causes of the clinical syndrome of frontotemporal lobar degeneration which has three subtypes. Pick's disease pathology is associated more with the frontotemporal dementia and progressive nonfluent aphasia subtypes than the semantic dementia subtype.

RG2833, a histone deacetylase inhibitor developed by Repligen, was acquired by BioMarin Pharmaceutical in January 2014. The first human trials with this compound began in 2012.

Horizon Pharma's development plan of interferon gamma-1B for treatment of FA was given fast track designation by the Food and Drug Administration in 2015.

In its trials released in December 2016, however, the results showed no improvements over placebo in patients.

Tauopathy belongs to a class of neurodegenerative diseases associated with the pathological aggregation of tau protein in neurofibrillary or gliofibrillary tangles in the human brain. Tangles are formed by hyperphosphorylation of a microtubule-associated protein known as tau, causing it to aggregate in an insoluble form. (These aggregations of hyperphosphorylated tau protein are also referred to as paired helical filaments). The precise mechanism of tangle formation is not completely understood, and it is still controversial as to whether tangles are a primary causative factor in the disease or play a more peripheral role. Primary tauopathies, i.e., conditions in which neurofibrillary tangles (NFT) are predominantly observed, include:

- Primary age-related tauopathy (PART)/Neurofibrillary tangle-predominant senile dementia, with NFTs similar to AD, but without plaques.

- Chronic traumatic encephalopathy, including dementia pugilistica

- Progressive supranuclear palsy

- Corticobasal degeneration

- Frontotemporal dementia and parkinsonism linked to chromosome 17

- Lytico-Bodig disease (Parkinson-dementia complex of Guam)

- Ganglioglioma and gangliocytoma

- Meningioangiomatosis

- Postencephalitic parkinsonism

- Subacute sclerosing panencephalitis

- As well as lead encephalopathy, tuberous sclerosis, Hallervorden-Spatz disease, and lipofuscinosis

Neurofibrillary tangles were first described by Alois Alzheimer in one of his patients suffering from Alzheimer's disease (AD), which is considered a secondary tauopathy. AD is also classified as an amyloidosis because of the presence of senile plaques.

The degree of NFT involvement in AD is defined by Braak stages. Braak stages I and II are used when NFT involvement is confined mainly to the transentorhinal region of the brain, stages III and IV when there's also involvement of limbic regions such as the hippocampus, and V and VI when there's extensive neocortical involvement. This should not be confused with the degree of senile plaque involvement, which progresses differently.

In both Pick's disease and corticobasal degeneration, tau proteins are deposited as inclusion bodies within swollen or "ballooned" neurons.

Argyrophilic grain disease (AGD), another type of dementia, is marked by an abundance of argyrophilic grains and coiled bodies upon microscopic examination of brain tissue. Some consider it to be a type of Alzheimer's disease. It may co-exist with other tauopathies such as progressive supranuclear palsy and corticobasal degeneration, and also Pick's disease.

Huntington's disease (HD): a neurodegenerative disease caused by a CAG tripled expansion in the Huntington gene is the most recently described tauopathy (Fernandez-Nogales et al. Nat Med 2014). JJ Lucas and co-workers demonstrate that, in brains with HD, tau levels are increased and the 4R/3R balance is altered. In addition, the Lucas study shows intranuclear insoluble deposits of tau; these "Lucas' rods" were also found in brains with Alzheimer's disease.

Tauopathies are often overlapped with synucleinopathies, possibly due to interaction between the synuclein and tau proteins.

The non-Alzheimer's tauopathies are sometimes grouped together as "Pick's complex" due to their association with frontotemporal dementia, or frontotemporal lobar degeneration.

Idebenone, an antioxidant, was recently removed from the Canadian market in 2013 due to lack of effectiveness. A Cochrane review on antioxidants and other pharmacological treatment of patients with Friedreich ataxia concluded that there is limited but not persuasive evidence of efficacy.

there are no USFDA-approved medications for the treatment of mild cognitive impairment. Moreover, as of January 2018, there is no high-quality evidence that supports the efficacy of any pharmaceutical drugs or dietary supplements for improving cognitive symptoms in individuals with mild cognitive impairment. A moderate amount of high-quality evidence supports the efficacy of regular physical exercise for improving cognitive symptoms in individuals with MCI. The clinical trials that established the efficacy of exercise therapy for MCI involved twice weekly exercise over a period of six months. A small amount of high-quality evidence supports the efficacy of cognitive training for improving some measures of cognitive function in individuals with mild cognitive impairment. Due to the heterogeneity among studies which assessed the effect of cognitive training in individuals with MCI, there are no particular cognitive training interventions that have been found to provide greater symptomatic benefits for MCI relative to other forms of cognitive training.

The American Academy of Neurology's (AAN) clinical practice guideline on mild cognitive impairment from January 2018 stated that clinicians "should" identify modifiable risk factors in individuals with MCI, assess functional impairments, provide treatment for any behavioral or neuropsychiatric symptoms, and monitor the individual's cognitive status over time. It also stated that medications which cause cognitive impairment "should" be discontinued or avoided if possible. Due to the lack of evidence supporting the efficacy of cholinesterase inhibitors in individuals with MCI, the AAN guideline stated that clinicians who choose to prescribe them for the treatment of MCI "must" inform patients about the lack of evidence supporting this therapy. The guideline also indicated that clinicians "should" recommend that individuals with MCI engage in regular physical exercise for cognitive symptomatic benefits; clinicians "may" also recommend cognitive training, which appears to provide some symptomatic benefit in certain cognitive measures.

As MCI may represent a prodromal state to clinical Alzheimer's disease, treatments proposed for Alzheimer's disease, such as antioxidants and cholinesterase inhibitors, could potentially be useful; however, there is no evidence to support the efficacy of cholinesterase inhibitors for the treatment of mild cognitive impairment. Two drugs used to treat Alzheimer's disease have been assessed for their ability to treat MCI or prevent progression to full Alzheimer's disease. Rivastigmine failed to stop or slow progression to Alzheimer's disease or to improve cognitive function for individuals with mild cognitive impairment; donepezil showed only minor, short-term benefits and was associated with significant side effects.

In a two-year randomized trial of 168 people with MCI given either high-dose vitamins or placebo, vitamins cut the rate of brain shrinkage by up to half. The vitamins were the three B vitamins folic acid, vitamin B6, and vitamin B12, which inhibit production of the amino acid homocysteine. High blood levels of homocysteine are associated with increased risk of cognitive decline, dementia, and cardiovascular disease. A single study from 2012 showed a possible connection between macronutrient intake and development of MCI. It is also suggested that a dietary pattern with relatively high caloric intake from carbohydrates and low caloric intake from fat and proteins may increase the risk of MCI or dementia in elderly persons

Experimental non-pharmacological treatments for MCI include transcranial magnetic stimulation and transcranial direct current stimulation; the efficacy of these interventions for the treatment of MCI has not yet been established.

Prevalence is estimated to be 0.005%. The age of onset has been found to be under 15 years in 40% of cases while it is between 10 and 14 years in one third of the cases. Females outnumber males, 4 to 1. Only 3% have attacks after age 52.

HDL1 is an unusual, autosomal dominant familial prion disease. Only described in one family, it is caused by an eight-octapeptide repeat insertion in the "PRNP" gene. More broadly, inherited prion diseases in general can mimic HD.

Succinic acid has been used successfully to treat MELAS syndrome, and also Leighs disease. Patients are managed according to what areas of the body are affected at a particular time. Enzymes, amino acids, antioxidants and vitamins have been used.

Also the following supplements may help:

- CoQ10 has been helpful for some MELAS patients. Nicotinamide has been used because complex l accepts electrons from NADH and ultimately transfers electrons to CoQ10.

- Riboflavin has been reported to improve the function of a patient with complex l deficiency and the 3250T-C mutation.

- The administration of L-arginine during the acute and interictal periods may represent a potential new therapy for this syndrome to reduce brain damage due to impairment of vasodilation in intracerebral arteries due to nitric oxide depletion.

- There is also a case report where succinate was successfully used to treat uncontrolled convulsions in MELAS patients, although this treatment modality is yet to be thoroughly investigated or widely recommended.

The journal of child neurology published a paper in 2012, Buccal swab analysis of mitochondrial enzyme deficiency and DNA defects in a child with suspected myoclonic epilepsy and ragged red fibers (MERRF), discusses possible new methods to test for MERRF and other mitochondrial diseases, through a simple swabbing technique. This is a less invasive techniques which allows for an analysis of buccal mitochondrial DNA, and showed significant amounts of the common 5 kb and 7.4 kb mitochondrial DNA deletions, also detectable in blood. This study suggests that a buccal swab approach can be used to informatively examine mitochondrial dysfunction in children with seizures and may be applicable to screening mitochondrial disease with other clinical presentations.

Proceedings of the National Academy of Science of the United States of America published an article in 2007 which investigate the human mitochondrial tRNA (hmt-tRNA) mutations which are associated with mitochondrial myopathies. Since the current understanding of the precise molecular mechanisms of these mutations is limited, there is no efficient method to treat their associated mitochondrial diseases. All pathogenic mutants displayed pleiotropic phenotypes, with the exception of the G34A anticodon mutation, which solely affected aminoacylation.

Like many mitochondrial diseases, there is no cure for MERRF, no matter the means for diagnosis of the disease. The treatment is primarily symptomatic. High doses of Coenzyme Q10, B complex vitamins and L-Carnitine are the drugs that patients are treated with in order to account for the altered metabolic processed resulting in the disease. There is very little success with these treatments as therapies in hopes of improving mitochondrial function. The treatment only alleviates symptoms and these do not prevent the disease from progressing. Patients with concomitant disease, such as diabetes, deafness or cardiac disease, are treated in combination to manage symptoms.

Although no cure currently exists, there is hope in treatment for this class of hereditary diseases with the use of an embryonic mitochondrial transplant.

Transneuronal degeneration is the death of neurons resulting from the disruption of input from or output to other nearby neurons. It is an active excitotoxic process when a neuron is overstimulated by a neurotransmitter (most commonly glutamate) causing the dysfunction of that neuron (either damaging it or killing it) which drives neighboring neurons into metabolic deficit, resulting in rapid, widespread loss of neurons. This can be either anterograde or retrograde, indicating the direction of the degeneration relative to the original site of damage (see types). There are varying causes for transneuronal degeneration such as brain lesions, disconnection syndromes, respiratory chain deficient neuron interaction, and lobectomies. Although there are different causes, transneuronal degeneration generally results in the same effects (whether they be cellular, dendritic, or axonal) to varying degrees. Transneuronal degeneration is thought to be linked to a number of diseases, most notably Huntington's disease and Alzheimer's disease, and researchers recently have been performing experiments with monkeys and rats, monitoring lesions in different parts of the body to study more closely how exactly the process works.

Aside from discontinuation of glucocorticoid medication, potential treatments discussed in the research literature include:

- anti-glucocorticoids

- psychoactive drugs that up-regulate the GRII glucocorticoid receptor:

- tricyclic antidepressants: Desipramine, Imipramine, and Amitriptyline (SSRIs do not )

- serotonin antagonists: Ketanserin

- mood stabilizers: Lithium

- corticotropin-releasing hormone (CRH) antagonists

- glutamate antagonists

- dehydroepiandrosterone (DHEA)

- small molecule brain-derived neurotrophic factor (BDNF) analogs

- stress reduction therapies and exercise.

A Mitochondrial encephalomyopathy is a form of encephalomyopathy that is associated with a mitochondrial disease.

Examples include MELAS and MERRF. These conditions can sometimes present together.

KSS is sometimes included in this category, but it is not included in this category in MeSH.

In medicine, proteopathy (Proteo- ["pref". protein]; -pathy ["suff". disease]; proteopathies "pl".; proteopathic "adj".) refers to a class of diseases in which certain proteins become structurally abnormal, and thereby disrupt the function of cells, tissues and organs of the body. Often the proteins fail to fold into their normal configuration; in this misfolded state, the proteins can become toxic in some way (a gain of toxic function) or they can lose their normal function. The proteopathies (also known as proteinopathies, protein conformational disorders, or protein misfolding diseases) include such diseases as Creutzfeldt–Jakob disease and other prion diseases, Alzheimer's disease, Parkinson's disease, amyloidosis, and a wide range of other disorders (see List of Proteopathies).

The concept of proteopathy can trace its origins to the mid-19th century, when, in 1854, Rudolf Virchow coined the term amyloid ("starch-like") to describe a substance in cerebral corpora amylacea that exhibited a chemical reaction resembling that of cellulose. In 1859, Friedreich and Kekulé demonstrated that, rather than consisting of cellulose, "amyloid" actually is rich in protein. Subsequent research has shown that many different proteins can form amyloid, and that all amyloids have in common birefringence in cross-polarized light after staining with the dye Congo Red, as well as a fibrillar ultrastructure when viewed with an electron microscope. However, some proteinaceous lesions lack birefringence and contain few or no classical amyloid fibrils, such as the diffuse deposits of Aβ protein in the brains of Alzheimer patients. Furthermore, evidence has emerged that small, non-fibrillar protein aggregates known as oligomers are toxic to the cells of an affected organ, and that amyloidogenic proteins in their fibrillar form may be relatively benign.