Neurological conditions affect the brain, the spinal cord and the nerves running to the rest of the body. Some are neurodegenerative, meaning nerve cells are gradually lost. Others involve nerves that signal wrongly rather than nerves that die. This page is a way in to the specific conditions.
By the numbers in Canada
3.6 millionpeople in Canada are affected by neurological conditions, according to the national population health study of neurological conditions. These conditions account for more than half of Canadians who need continuing care.
More than 5 million people in Canada are affected by migraine, a neurological condition rather than an ordinary headache. Source: Migraine Canada, 2025
Alzheimer’s disease: the most common cause of dementia, a specific disease of the brain that gradually affects memory, language and judgement.
Dementia: the umbrella term for the symptoms Alzheimer’s disease and other brain conditions cause. About 771,939 people in Canada were living with dementia at the start of 2025.
Memory loss and mild cognitive impairment: memory or thinking below what is expected for your age, while daily life is still manageable. It does not always progress.
Parkinson’s disease: brain cells that make dopamine are gradually lost, bringing tremor, stiffness, slowness and poor balance. About 111,000 people aged 40 and older in Canada live with parkinsonism.
Multiple sclerosis: the immune system damages the coating around nerves in the brain, spinal cord and optic nerves. Canada has one of the highest rates in the world, about 90,000 people.
Trigeminal neuralgia: sudden, brief, electric-shock-like pain in the face, often set off by a breeze or brushing your teeth.
Peripheral neuropathic pain: burning or shooting pain from damaged nerves in the hands, feet or limbs, often related to diabetes.
Migraine and headache disorders: attacks of head pain with nausea and sensitivity to light or sound, affecting more than 5 million people in Canada.
Age is the strongest risk factor for dementia and for Parkinson disease, but blood pressure, hearing and head injury also affect brain health. Illustrative photograph.
What these conditions have in common
They all involve the nervous system, and they are assessed the same way: a careful history, a neurological examination, then imaging or nerve testing only where it changes the answer. Because the nervous system controls everything, a problem in one place shows up as very different symptoms depending on where it sits. Two people with the same diagnosis can look nothing alike.
Several also share risk factors that surprise people. Blood pressure, blood sugar, cholesterol, activity, smoking, untreated hearing loss and head injury all affect brain health, which is why brain and heart care now overlap. Beyond that, the grouping is administrative: migraine and Alzheimer’s disease share this list because a neurologist sees both, not because they are related.
For most conditions here, care is aimed at symptoms and at keeping you doing what matters to you. Multiple sclerosis is the exception, with disease-modifying treatment well established. A health care team may discuss:
Medicines aimed at symptoms, such as dopamine-based treatment in Parkinson’s disease, or preventive and acute migraine medicines
Disease-modifying therapies, which exist for multiple sclerosis and are newer in Alzheimer’s disease
Medicines used specifically for nerve pain, which differ from ordinary painkillers
Physiotherapy, occupational therapy and speech-language therapy
Support for sleep, mood and thinking, since these change how the main condition feels
Procedures in selected cases, such as deep brain stimulation or nerve procedures for facial pain
Care partner support, home care and long-term care as needs change
Several of these decisions are finely balanced. They belong to you and your own clinician, and nothing here is a recommendation about any of them.
When to talk to a doctor
Sudden weakness or numbness on one side, a drooping face, trouble speaking, sudden loss of vision, or a sudden severe headache unlike any before needs emergency care. Call 911, because these can be signs of stroke and treatment is time-critical.
A first seizure, or a headache with fever and a stiff neck, needs emergency care.
Spreading weakness or numbness, or new loss of bladder or bowel control, needs same-day assessment.
New confusion, or a change in memory or behaviour over weeks rather than years, should be assessed promptly.
Memory changes that worry you or your family are worth an appointment, since some causes can be treated.
Why research in this area matters
For most conditions in this group, nothing available today stops the underlying process. Multiple sclerosis care has changed considerably over three decades of research, which shows what is possible. Alzheimer’s disease and Parkinson’s disease are earlier in that arc: treatments aimed at the biology rather than the symptoms are now in trials, as are ways of finding these diseases years before symptoms appear. Nerve pain research is looking for options that are not opioids.
Studies are how any of this is tested, and they often need people at a specific stage. Taking part is voluntary, you give informed consent first, and you can withdraw at any time without affecting your regular care. No one can tell in advance whether a study will help you personally.
This page is written in plain language for people considering clinical research. It is general health information, not medical advice, and it does not replace a conversation with your own doctor or nurse practitioner.
Common questions
What is the difference between neurological and neurodegenerative?
Neurological covers anything affecting the brain, spinal cord or nerves. Neurodegenerative is a subset in which nerve cells are gradually lost over time, as in Alzheimer's disease and Parkinson's disease. Migraine and trigeminal neuralgia are neurological but not neurodegenerative: the nerves are signalling abnormally rather than dying off.
Is memory loss always the start of dementia?
No. Forgetting a name and recalling it later is common with age. Mild cognitive impairment means memory or thinking is measurably below what is expected but daily life is still manageable, and it does not always progress. Thyroid problems, vitamin deficiencies, sleep problems, depression and some medicines can also affect memory, and several of those can be addressed.
Why do these conditions need clinical research?
Because for most of them nothing available today stops the underlying process. Trials test new medicines, devices and rehabilitation programs, and they also study how to find these conditions earlier. Taking part is voluntary, informed consent comes first, and you can withdraw at any time without affecting your regular care.
What to do next
Talk to your doctor. This guide is information, not medical advice.
JoinAStudy.ca provides information about clinical research and does not provide medical advice, diagnosis, or treatment. Only a qualified study doctor can determine your eligibility for a study. Participation is always voluntary.
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