ONDRI’s Diseases Studied

Definition of neurodegenerative diseases

Neurodegeneration is defined by the gradual loss or death of cells in the brain & spinal cord. Aging is the strongest risk factor for neurodegenerative diseases. Some cases are hereditary in nature.  Neurodegenerative diseases are not curable. They typically present as a series of symptoms, some of which are associated with dementia.

Neurodegeneration and dementia

Dementia is the progressive decline of thinking ability and memory, leading to day-to-day dependence on others.

By studying several related neurodegenerative diseases and stroke, ONDRI researchers are attempting to unravel the complexity of dementia by discovering novel ways to improve dementia diagnosis and treatment.

ONDRI’s diseases studied:

Alzheimer’s disease (AD) / Mild cognitive impairment (MCI)

Alzheimer’s disease is not a normal part of aging. It is estimated that 60% of dementia cases are caused by Alzheimer’s disease, which develops slowly and worsens over time. Symptoms include difficulty remembering, making decisions and performing everyday activities.  

Mild cognitive impairment causes a slight but noticeable similar decline (e.g. memory loss), but day-to-day functions are preserved. When MCI is present, it is often followed closely by physicians as it can be the first sign of AD. Less commonly, it can also be a risk factor for other neurodegenerative diseases.   

Related resources:

Sandra Black, MD, PhD., on the difference between Alzheimer’s disease and Mild Cognitive Impairment
Sandra Black, MD, PhD., on the difference between Alzheimer’s disease and normal aging

Amyotrophic lateral sclerosis (ALS)

Today approximately 3,000 Canadians live with Amyotrophic Lateral Sclerosis (also known as Lou Gehrig’s disease or motor neuron disease). ALS is a disease that gradually causes paralysis, due to the loss of motor neurons that allow the brain to communicate with the muscles in the body.

Over time, as the nerves that control the muscles break down, a person living with ALS will lose the ability to walk, talk, eat, swallow, and eventually breathe. The frequency and seriousness of cognitive changes in ALS varies widely, and some people may develop concurrent Frontotemporal Dementia (FTD) – see definition below.

Cerebrovascular disease (CVD)

Cerebrovascular disease is caused by damaged blood vessels in the brain. CVD can result from stroke. It is the leading cause of adult neurological (brain) disability. When blood vessels lose their effectiveness, the brain can suffer reduction of blood flow. CVD is often present with other causes of dementia and can worsen their impact.

Related resources:

Richard Swartz, MD, PhD., on provides an overview of vascular cognitive impairment (technical)

Frontotemporal Dementia (FTD)

Frontotemporal dementia refers to a group of diseases caused by progressive cell deterioration in the brain’s frontal lobes (behind the forehead) or temporal lobes (behind the ears). Symptoms can start as young as 45-65 years of age, and typically progress at a rapid, steady rate.

There are 2 main types of FTD:

  1. Behavioural variant FTD (bvFTD) takes its greatest toll on personality and behaviour.
  2. Primary progressive aphasia (PPA) affects language skills in early stages, but can affect behaviour as it advances.

In addition, there are variants of FTD that can present as a parkinsonian disorder or as a motor neuron disease.

Video: Living with FTD (produced by Durham Regional Police Services)

To access closed captioning, or read the words, click on CC at bottom of the video

Parkinson’s disease (PD)

Over 100,000 Canadians are living with Parkinson’s disease, a number expected to double by 2031. Approximately 30% of these are also living with dementia. PD is a slowly progressing disease of the brain’s movement control centre that causes both motor and non-motor symptoms. The most common symptoms are tremors, slowness, stiffness, impaired balance, and rigidity of muscles. As PD progresses, non-motor symptoms may also appear, such as depression, difficulty swallowing, or cognitive changes.