Neuroscience

Neurodegenerative diseases

Neurodegenerative diseases are a group of disorders that involve the progressive degeneration of the structure and function of the nervous system. These diseases primarily affect the neurons, the functional cells of the brain, spinal cord, and peripheral nervous system. As neurons progressively degenerate or die, it leads to impairments in cognition, movement, and other vital functions. Most neurodegenerative diseases are chronic, worsen over time, and currently have no cure.

1. Alzheimer's Disease

• Overview: Alzheimer's is the most common cause of dementia, characterized by the gradual decline in memory, cognitive function, and the ability to perform everyday activities. It involves the buildup of amyloid plaques and tau tangles in the brain, leading to neuron death.
• Symptoms: Memory loss, confusion, difficulty with language and communication, changes in personality, and eventually the loss of motor control.

2. Parkinson's Disease

• Overview: Parkinson's disease primarily affects movement and is caused by the death of dopamine-producing neurons in the substantia nigra, a part of the brain involved in motor control. This results in motor dysfunction and movement difficulties.
• Symptoms: Tremors, rigidity, bradykinesia (slowness of movement), postural instability, and difficulty with balance and coordination. As the disease progresses, cognitive symptoms, such as memory problems, may also emerge (Parkinson's dementia).

3. Amyotrophic Lateral Sclerosis (ALS)

• Overview: ALS, also known as Lou Gehrig's disease, is a progressive neurodegenerative disorder that affects motor neurons, leading to muscle weakness, loss of motor control, and eventually paralysis. ALS usually leads to death within 3 to 5 years after diagnosis due to respiratory failure.
• Symptoms: Muscle weakness, difficulty speaking, swallowing, and breathing. ALS does not typically affect cognitive function, but in some cases, cognitive impairment or behavioral changes may occur.

4. Huntington's Disease

• Overview: Huntington's disease is an inherited neurodegenerative disorder caused by a mutation in the HTT gene, leading to abnormal production of the protein huntingtin. This results in the progressive degeneration of neurons in the brain, particularly in the basal ganglia.
• Symptoms: Uncontrolled movements (chorea), difficulty with voluntary movement, cognitive decline, and psychiatric symptoms like depression and irritability. The disease typically appears in mid-life and worsens over time.

5. Multiple Sclerosis (MS)

• Overview: MS is an autoimmune disorder where the immune system attacks the protective covering of nerve fibers (myelin) in the central nervous system, leading to inflammation and scarring. Over time, this damages the nerve fibers themselves.
• Symptoms: Symptoms can vary widely and include fatigue, difficulty walking, muscle weakness, numbness, vision problems, and in some cases, cognitive impairment.