Alzheimer’s disease is a progressive neurodegenerative disorder that can result in significant memory impairment. In saying that it is progressive, this means that it will progress overtime. It is mainly caused by the deposition of a protein that builds up both in and around brain cells. This also leads to the formation of plaques around the brain cells that hinder brain activity.

In addition to memory loss, patients in the late stages of Alzheimer’s have speech challenges and difficulty registering their surroundings properly.

Vascular dementia is the second most common cause of dementia in the US. As the name suggests, the main cause of vascular dementia is a problem with the blood vessel – either ischemic or hemorrhagic stroke and small vessel ischemic disease – leading to cognitive loss. Stenosis and blockage in brain blood vessels, impaired brain blood circulation, and the brain’s deprivation from vital nutrients could also cause vascular dementia.

Alzheimer’s and vascular dementia have many overlapping symptoms, such as cognitive impairment, lack of concentration, difficulty in understanding and communicating, and memory loss. At times, Vascular dementia has a more step-wise course of worsening rather than the more smooth progressive worsening in Alzheimer’s dementia.

To prevent vascular dementia, it is important to control vascular risk factors such as high blood pressure, diabetes, high cholesterol and smoking.

Lewy body dementia is a progressive neurodegenerative disease caused by the deposition of abnormal proteins, called alpha-synuclein, in the brain. The alpha-synuclein clusters result in chemical changes in the brain, leading to symptoms such as abnormal movements, difficulty with thought process, and behavior.

Sometimes it is difficult to diagnose this type of dementia since the symptoms overlap with Alzheimer’s and schizophrenia symptoms. The abnormal movements are similar to those in Parkinson disease, and so this is considered a “Parkinson plus” syndrome. Therefore, evaluation by memory disorder and movement disorder specialists can help reach the correct diagnosis.

Frontotemporal dementia affects the frontal and temporal lobes of the brain, which control language, behavior, and personality. Frontotemporal dementia occurs when either one of these lobes shrinks and does not function properly.

Symptoms vary according to the damaged area and can include speech problems or behavioral changes, including disinhibited (or uncontrolled) and socially inappropriate behavior, a decline in empathy, and a dramatic change in eating habits. Symptoms of frontotemporal dementia often begin in late 40s and 50s. The exact cause of this kind of dementia is still unknown.

Parkinson’s dementia is diagnosed if patients with Parkinson’s disease experience symptoms of dementia after a year of the onset of their motor difficulties. It is characterized by a loss of memory, trouble with concentrating, and difficulty in thinking and learning due to changes in the neurotransmitters in the brain., including dopamine.

Corticobasal degeneration is a rare progressive brain disease. It is a neurological abnormality caused by the loss of cells in some regions of the brain. People with the disorder tend to lose motor skills in one part of the body, which eventually spreads to the rest of the body. Initial symptoms include rigidity in the limbs, which prevent the patient from voluntarily moving the leg or arm. Over time, behavioral changes develop. The leading cause of this disease is the loss of brain tissue for unknown reasons. Therapies are conducted for each of the symptoms present.

Progressive Supranuclear Palsy (PSP) is similar to CBD due to the deterioration of certain areas in the brain, in this case involving the brainstem. It leads to imbalance, slowed movement, trouble in moving eyes, and loss of memory. The first symptom is usually a loss of balance.

Huntington’s is a progressive disease that affects a person’s motor abilities. Huntington’s is a genetic condition that begins with trouble in movement. The onset of dementia affects memory as a person is unable to learn new things and loses their sense of judgment. As the disease progresses further, a person’s intellect declines. Huntington’s disease can also affect people’s mental health. Therapies and medications directed towards symptoms can help.

Normal Pressure Hydrocephalus (NPH) is a rare neurological disease that creates trouble in movement and leads to dementia. Due to enlarged ventricles – which are the areas cerebrospinal fluid collects in the brain – this can lead to a triad of difficulty walking with a particular pattern of gait, difficulty controlling urine, and memory changes. Due to its similarity to other neurological disorders, many tests are required to diagnose it, and it often goes undiagnosed.

Creutzfeldt-Jakob disease is a rare yet fatal abnormality of the brain that can result in death within a year. Initial symptoms include weak memory, loss of body control, behavioral changes, and blurred vision, which escalate with time and lead to complete loss of memory and blindness. CJD is caused by abnormal forms of proteins in the brain, called “prions.”

HIV associated dementia (AIDS dementia) is caused by an infection that spreads across the brain and escalates with the symptoms of dementia. The membranes of the brain swell, causing abnormality in brain functions.