Principles of Neuroscience Lecture 28 Disorders of the Nervous System I

Question 0

What are the categories of neurally related disease?

Answer 0

Mental disorder
Neurological disorder
Learning or developmental disorder
Drug addiction

Question 1

How many people worldwide suffer from neurological disease?

Answer 1

450 million

Question 2

Describe the difference between mental disorders and neurological disorders.

Answer 2

It is an old fashioned view that mental disorders have no organic basis, and are merely functional problems of the brain
Neurological disorders, however, have an organic basis that you can point to

Question 3

What is the difference between psychiatry and neurology?

Answer 3

Neurology: looking at organic causes of disease
Psychiatry: diseases that are thought to be merely functional, no problem with the machinery

Question 4

What are learning and developmental disorders?

Answer 4

These are due to injury to the developing nervous system in childhood

Question 5

What are some examples of learning and developmental diseases?

Answer 5

Trisomy 21
Fragile X
Tay sachs
Neurotropic infections

Question 6

What do mental disorders affect?

Answer 6

Cognition, emotion, behavioural control

Question 7

Describe the characteristic onset of mental disorders

Answer 7

Usually early onset, with chronic recurrence throughout life

Question 8

What is the aetiology of mental disorders?

Answer 8

Complex, however gender does play a role.

Genetics and environment plays a role

Question 9

What are some significant examples of mental disorders?

Answer 9

Schizophrenia
Bipolar affective disorder
Major depressive disorder
Panic disorders

Question 10

Describe the evolution of pharmacological treatment for mental disorders

Answer 10

In the 50’s they found that some drugs could affect mental disorders

Thus, there must be some organic basis to these mental disorders

Question 11

Which drugs are effective against mental disorders? How do these work?

Answer 11

Benzodiazepines were especially effective, for example Valium (diazepam)

Question 12

Describe what is significant about the treatment with drugs of schizophrenia

Answer 12

There are many different types of drugs

They lower the affinity the drug with D2, the higher the dose required for effective control. This is striking, because it says that there is a direct connection between binding of the drug and relief from the disorder

Question 13

What are the major neurological diseases?

Answer 13

Epilepsy
Alzheimer’s
Multiple sclerosis

Question 14

What is the aetiology of multiple sclerosis?

Answer 14

Unclear, however there is a profile for people who get this disease

Young, female, middle class, temperate climate
Eg. Jacqueline du pré

Question 15

What is the pathophysiology of multiple sclerosis?

Answer 15

Myelin on the neurons is destroyed by an auto immune response

These neurons may be motor or sensory etc.

Question 16

What are the clinical manifestations of multiple sclerosis?

Answer 16

Vision, sensation, movement, speech, cognition, balance are all affected

Depression

Muscle weakness

Question 17

What is the pathophysiology of Alzheimer’s disease?

Answer 17

Extracellular deposits of amyloid protein plaques in the brain
Intracellular tangles of tau protein
Disruption of the neuronal cytoskeleton

1. Deposition begins in the hippocampus, over many years, the hippocampus is destroyed.
2. Inability to store new memories in the neocortex
3. Spreads to the rest of the brain, distinctive pattern: median temporal lobe

Question 18

What are the clinical manifestations of Alzheimer’s ?

Answer 18

Memory loss

Cognition and intellectual function are affected

Question 19

What are the types of cytoskeleton?

Answer 19

Microtubule
Actin
Neurofilament

Question 20

Differentiate between amyloid plaques and tau tangles

Answer 20

Amyloid plaque form outside the neurons

Tau tangles form inside cells when there has been amyloid plaque formation

Question 21

What is the definition of epilepsy?

Answer 21

Two or more seizures

Ie. the seizures must be recurrent

Question 22

How can epilepsy be detected?

Answer 22

EEG shows massive synchronous waves of brain activity

Question 23

What is going on during a seizure?

Answer 23

Transient, hyper-synchronous, abnormal neuronal activity

Question 24

What are the types of epilepsy?

Answer 24

1. Idiopathic: genetic basis, childhood onset
2. Secondary or symptomatic epilepsy: CNS injury or disorder
3. Cryptogenic: no idea what causes it

Question 25

What is the genetic basis for epilepsy?

Answer 25

There is a link between epilepsy and mutations in proteins that are related to neural excitability

Such as ion channels or neurotransmitter receptors

Question 26

How could one ion channel affect neuronal firing?

Answer 26

This could cause an imbalance in the excitation of inhibition of a neurons, leading to hyper synchronous firing and convulsions

Question 27

What treatments do we have for epilepsy?

Answer 27

Dilantin, Zonisamide, Epilim

We have drugs, but we don’t really know how they work

Most likely, they work to:

• enhance GABA
• block Na or Ca channels

Question 28

What is the normal function of tau?

Answer 28

It is involved in the stability of the neuronal cytoskeleton