Neuro. & Degen.

Question 1

Define degenerative disorders.

Answer 1

Chronic progressive disorders characterized by a downward trend of ill-health.

Question 2

Outline the mechanisms responsible for degenerative changes in the body.

Answer 2

1. Oxygen free radical damage; free radicals can cause large chain chemical reactions.
2. Mitochondrial abnormalities; long-term disruption of mitochondrial energy production
3. Cytoskeleton abnormalities; disease associated with cytoskeletal abnormalities (e.g. cancer, pulmonary fibrosis, etc…)
4. Apoptosis

Question 3

Name 2 examples of genetic degenerative disorders and briefly describe them.

Answer 3

Duchenne muscular dystrophy; an x-linked recessive disorder which causes wasting of skeletal muscle fibers. (Absence of the dystrophin protein affects the stability of the muscle membrane making it progressively weak).
Huntington’s disease; an autosomal dominant disorder which causes gradual destruction of neurons to the basal ganglia and cerebral cortex. (Ventricles are noticeably larger)

Question 4

What happens to the body as a result of ageing?

Answer 4

Ageing characterized by reduced efficiency in body systems controlling homeostasis. Age-related immune problems occur with more frequency (e.g. autoimmune disease).

Question 5

What is a commonly occurring osteopathic disease usually present with age? Outline.

Answer 5

Osteoarthritis; destruction of articular cartilage in weight baring joints(e.g. knee). Results in loss of cartilage, development of bony spurs, pain, swelling, and stiffness with gradual loss of function.

Question 6

What is rheumatoid arthritis? How does it affect the body?

Answer 6

RA; enables the immune system to attack connective tissue(i.e. destroys joints and causes inflammation).
Symptoms; fatigue, loss of energy, muscle aches, etc…
Treatments; steroids and NSAIDs used to reduce inflammation.

Question 7

Describe multiple sclerosis.

Answer 7

a chronic, typically progressive disease involving damage to the sheaths of nerve cells in the brain and spinal cord, whose symptoms may include numbness, impairment of speech and of muscular coordination, blurred vision, and severe fatigue.

Question 8

What is CNS degenerative disease and how does the body react to it?

Answer 8

CNS degenerative disease is characterized by progressive neuron loss in specific brain regions (e.g. basal ganglia). The body’s non-specific cellular responses to chronic damage or injury in the CNS is gliosis, this causes glial cells to multiply and form scar tissue which replaces damaged neurons.

Question 9

Outline Parkinson’s disease in detail.

Answer 9

PD is a progressive neurological system that affects movement(brain becomes incapable of exerting fine inhibitory control for motor activities) which is caused by reduction of neurotransmitters called dopamine in mid-brain region(substantia nigra). Symptoms; muscle rigidity, tremors, etc…

Question 10

Define dementia.

Answer 10

Dementia is a general mental deterioration due to variety of underlying factors. Includes loss of cognitive function, reasoning, memory, etc…

Question 11

Explain/describe reversible and irreversible dementia (any examples?)?

Answer 11

Reversible; can be caused by depression(e.g. stress), medication(e.g. diazepam), infection(e.g. response to fever), malnutrition(e.g. impairs brain function).
Irreversible; brain function permanently damaged (usually cerebral cortex and basal ganglia affected). Irrversibale dementia’s include Alzheimer’s, Huntington’s, and Cruetzfeld-Jacob Disease.

Question 12

Describe vascular dementia. How does it differ from normal dementia?

Answer 12

VD is a problem with the blood supply to the cerebral cortex (neurons started of oxygen and die). Gradual loss of neurons leads to progressive dementia caused by hypertension, cerebral atherosclerosis, etc…

Question 13

Explain and outline Alzheimer’s disease.

Answer 13

Alzheimer’s is also acted with the loss of neurons and brain neurotransmitters(e.g. acetylcholine on cerebral cortex). Lesions occur when neurons die, plaques consist of fibrous protein called beta amyloid surrounded by dying nerve endings.

Question 14

List the causes of Alzheimer’s disease.

Answer 14

Slow viruses; could infect an individual and take 2-30 years to incubate (e.g. herpes)
Autoimmune process; increased levels of brain reactive antibodies have been detected.
Genetic defect; genetic link with come families regarding early-onset.
Diet; folic acid link.

Question 15

What is the progression of Alzheimer’s disease and its affect on the brain and body?

Answer 15

• Progressive memory loss with increasing inability to participate in daily activities.
• Individuals lose ability to recognize family; often becoming confused, experiencing personality changes.
• Causes of death for most people with the disease is infection(typically pneumonia).

Question 16

Give an example of a degenerative disease stemming from infection.

Answer 16

Cruztfeld-Jacob disease

Question 17

What is a common response in the brain to increased ICP?

Answer 17

Brain ischemia occurs when the raised ICP approaches systemic arterial blood pressure, thereby causing decreased cerebral perfusion and brain ischemia. Brain herniation is the shifting of the brain tissue from one space in the brain to another through various folds and openings.

Question 18

Distinguish between brain herniation and brain ischemia.

Answer 18

Herniation; movement in brain tissue from one compartment to another.
Ischemia; lack of oxygen in the brain.

Question 19

How is neurological function assessed? List.

Answer 19

History, imaging, lumbar puncture biopsies, electrophysiology, etc…

Question 20

What are the three categories of CNS disorders? Examples?

Answer 20

Developmental disorders
Systemic disorders
Intrinsic disorders

Question 21

Define polyneuropathy and how it may occur.

Answer 21

Polyneuropthay(peripheral nerve dysfunction) can occur in diabetes milliteus when patients have a loss of sensation at their extremities.

Question 22

Describe CNS disorders in the UMN category.

Answer 22

Upper motor neuron lesions include stroke, tumours and trauma. Damage to the spinal cord, brain stem or motor cortex is UMN. Result is increased muscle tone and reflexes, and muscle weakness.

Question 23

Describe CNS disorders in the LMN category.

Answer 23

Lower motor neuron signs include sciatica, back pain, polio and trauma. Damage to root, plexus or peripheral nerve. Result is decreased muscle tone, loss of reflexes, muscle twitches, muscle weakness and atrophy.

Question 24

Define developmental disorders, list causes, and examples.

Answer 24

Developmental disorders; caused by intrinsic(e.g. genetic) or extrinsic factors(e.g. environmental toxins). Developmental disorders include anencephaly, spina bifida, Down’s syndrome and Huntington’s.

Question 25

Define systemic disorders, list causes, and examples.

Answer 25

Systemic disorders; disorders of other body systems that either directly or indirectly impact upon the CNS. Systemic disorders include alcohol poisoning, endocrine failure(e.g. cretinism), homeostasis failure(e.g. diabetes).

Question 26

Define intrinsic disorders, list causes, and examples.

Answer 26

Intrinsic disorders; ischemia, hypoxia, trauma, etc…

Question 27

Define stroke.

Answer 27

Life-threatening condition caused by the blood supply to the brain getting cut off.

Question 28

List and describe at least 3 different causes of stroke.

Answer 28

Ischemia; decreased blood supply to part of the brain resulting in dysfunction or brain tissue death in that area.
Haemorrhagic; burst blood vessel, severe, higher mortality.
Thrombosis; obstruction of a blood vessel by a blood clot.

Question 29

Define neuropathic pain.

Answer 29

Pain derived or caused by the damage to the nerves that transmit information between the brain and the spinal cord from other parts of the body.

Question 30

What are the four most common types of neuropathic pain? Examples?

Answer 30

Neuropathic pain (affects somatosensory nerves);

• Mechanical nerve injury
  
  • Trauma, herniation, stroke, etc…
• Metabolic Disease
  
  • Painful diabetes neuropathy
• Viral infection
  
  • Shingles/trigeminal neuralgia
• Inflammation mechanisms
  
  • Multiple sclerosis

Question 31

Explain pains biological significance.

Answer 31

Pain serves as a safety mechanisms and alters the body of impending threats and insults to health. Having no pain can result in serious repercussions.

Question 32

What is the channelopathy or nonsense mutation gene that results in the congenital inability to experience pain (CIP)?

Answer 32

SCN9A & Nav1.7

Question 33

List and outline the three types of pain.

Answer 33

1. Nocicpetive Pain (Adaptive/Protective)
2. Inflammatory pain (Adaptive/Protective)
3. Pathological pain (Maladaptive)

*In order for treatment to be targeted each pain mechanisms behind the types of pain must be understood.

Question 34

What are nociceptors and their function?

Answer 34

Sensory receptors that detect signals from damaged tissue or the threat of damage and indirectly also respond to chemical released from the damaged tissue.

Question 35

Is neuropathic pain a chronic pathological type of pain (dysfunctional)?

Answer 35

Yes.

Question 36

Outline epilepsy and its risk factors.

Answer 36

Epilepsy presents with recurrent seizures caused by abnormal electrical discharge from cortical neurons. Risk factors; Brain damage, stroke, tumour, etc…

Question 37

What is the worst type of seizure, outline its mechanism and explain why its dangerous.

Answer 37

Tonic-clinic seizures are the worst due to the induced violent limb extension, jerking, then loss of consciousness and confusion.

Question 38

Describe the Pathogenesis of epilepsy.

Answer 38

1. Before loss of consciousness, an aura of unusual smell/sensory hallucinations, fear, etc.. can occur.
2. Seizure happen when neurons are activated in a synchronous pattern; normally neurons are excited and inhibited in a non-synchronous way.
3. Injuries can reorganize neural networks, so excitatory circuits increase. Inhibitory inter-neurons can also be affected.
4. Voltage gates Na and Ca channels and GABA levels are important. NMDA receptors are also involved.
5. Current drugs inhibit both channels (Phenytoin) and increase GABA (Phenobarbital)
6. In infants, mutations have been found in Na and K channels and GABA receptors.

Question 39

Define Myasthenia Gravis. Mechanisms? Treatments?

Answer 39

Myasthenia Gravis is an autoimmune disorder resulting in muscular weakness(Antibodies block ACh binding and ACh receptors, so muscle action potential is smaller). Treatments; Pyridostigmine is a cholinesterase inhibitor.

Question 40

Define synculeinopathy. Example?

Answer 40

Synucleinopathies are neurodegenerative diseases characterised by the abnormal accumulation of aggregates of alpha-synuclein protein in neurons, nerve fibres or glial cells (e.g. Parkinson’s disease)

Question 41

Define channelopathy. Examples?

Answer 41

Channelopathies are a group of diseases caused by the dysfunction of ion channel subunits or their interacting proteins(e.g. myasthenia gravis).