SPMM Neurosciences

Question 1

What is the Stanford- Binet intelligence scale?

Answer 1

A test of intelligence consisting of 120 items can be used to assess children to adulthood

Question 2

The Halstead-Reitan battery of tests was designed to improve reliability and accuracy of detecting

Answer 2

brain damage. It consists of 10 tests including trail-making test (visuomotor) and critical frequency flicker test (visual perception)

Question 3

Is the Raven’s progressive matrix a test of non-verbal or verbal intelligence?

Answer 3

Non-verbal

Question 4

Why is the Halstead-Reitan battery of tests helpful?

Answer 4

It can determine the location and effects of brain damage?

Question 5

The Wisconsin Card sorting test is a good test of?

Answer 5

Executive functioning (DLPFC)

Question 6

What does the paired-associative test assess for?

Answer 6

Verbal memory

Question 7

What is the Rey-Osterith test

Answer 7

A test of visual memory - ppts are required to replicate a complicated line draeing

Question 8

What does the Bender Visuo-Motor test assess for?

Answer 8

Screening measure for organic dysfunction

Question 9

Name some visuospatial memory tests for animals?

Answer 9

Spiked maze test, T test and the morris water maze test

Question 10

What is a sensorimotor gating test for animals

Answer 10

Latent-inhibition test

Question 11

What does the light-dark box in animal models test for?

Answer 11

Anxiety behaviours

Question 12

Name some neuropsychiatric diseases with trinucleotide repeats underlying genetic causes?

Answer 12

Huntingtons - CAG on short arm chromosome 4 - if > 40 repeats there is full penetrance
Fragile X syndrome - CCG on distal long arm of X chromosome - leads to fragile appearance. As on X chromosome more penetrance in males

Question 13

Phenylketonuria and Wilson’s disease are inherited in what genetic patterns?

Answer 13

Wilson’s Disease - autosomal recessive - APT7B gene on chromosome 7. Leads to excess hepatic secretion of copper into bile

Phenylketonuria - autosomal recessive - deficiency of phenylalanine hydroxylase enzyme and build up of phenylalanine in the body

Question 14

What are association studies?

Answer 14

Identify a specific disease locus - find frequency of specific alleles at marker locus in cases compared to controls (not causal - association only)

Question 15

Establishing a chromosomal location of disease locus is established by which studies?

Answer 15

Linkage studies

Question 16

Name two study methods that identify the function of genes?

Answer 16

Transgenesis and gene targetting

Question 17

Define the following

a) Silent mutation
b) Missense mutation
c) Nonsense mutation
d) Frame shift
e) Point mutation

Answer 17

a) Silent mutation - one triplet sequence replaced by another but same amino acid sequence is encoded

b) Missense mutation - new mutant codon specifies a different amino acid however this has variable effects on protein

c) Nonsense mutation - new mutant codon specifies a UUA, UGA or UAG which signals stop the amino acid sequence and nonfuncitonal protein

d) Frame shift - mutation, deletion or insertion is not a multiple of 3

e) Point mutation - substitution where one base is replaced by another. Transition if still a purine/pyrimidine or transverions if purine to pyramidine

Question 18

What do the terms incomplete penetrance and variable expression mean?

Answer 18

Incomplete penetrance - means that although the patient inherits an autosomal dominant disease it clinically doesn’t express itself in the patient.

Variable expression however refers to differences in the severity of disease expressed.

Question 19

What does phenocopy refer to?

Answer 19

A phenotypically indistinguishable condition but without the genes - i.e. EPSEs from Parkinson’s but no genes

Question 20

What does consanguinity do in Autosomal recessive disorders?

Answer 20

Increase the risk of inheritance

Question 21

How does X inactivation occur?

Answer 21

Via DNA methylation - all X chromosome except one are permanently inactivated one.

Inactivated ones have a characteristic Barr body appearance during interphase.

The inactivated X-chromosomes will not be active ever in future cells cycles

Question 22

What is unfavourable Lyonisation?

Answer 22

Where the X-Chromosome that is made inactive is the one carrying normal alleles (in x-linked recessive conditions) - here there can be manifesting heterozygotes - i.e if a female is a carrier she may then have the disease - however symptoms are mild and may go unnoticed.

Question 23

Name some x-linked recessive disorders

Answer 23

Haemophilia A/B
Muscular Dystrophy
Androgen Insensitivity

Question 24

Name two x-linked dominant disorders?

Answer 24

Rett’s syndrome (MECP2 gene - also leads to Angelman syndrome, Prader Wili syndrome, severe encephalopathy and progressive spasticity): form of x-linked mental retardation

Vitamin D resistant Rickett’s syndrome

As with autosomal dominant conditions - skipping is rare as heterozygous females will express the disease and only one X needed for males

Question 25

How is x-linked mental retardation classified?

Answer 25

Syndromic
- Fragile X
- Retts

Non-syndromic:
- Prader Wili
- Angelman

Question 26

Outline some mitochondrial inherited syndromes?

Answer 26

MELAS (myopathy, encephalopathy, lactic acidosis, recurrent stroke sydrome)

Leber’s hereditary optic neuropathy (LHON) - common cause of blindness in young males (bilateral loss of central vision), also presents with congenital cardiac abnormalities

As mitchondrial DNA is only present in ovum and not sperm head (body and tail shed) all mitochondrial DNA is maternally inherited

Chronic progressive external
ophthalmoplegia (CPEO);

Myoclonic epilepsy with ragged red fibres
(MERRF)

Mitochondrial encephalomyopathy

Kearus-Sayre syndrome includes ophthalmoplegia, heart block, cerebellar ataxia, deafness and mental
deficiency due to long deletions and rearrangements.

Question 27

What is a dynamic mutation

Answer 27

Occurs in context of trinucleotide repeat mutations - here if there is an expansion of trinucleotide repeats there can be anticipation where the disease presents earlier in life.

Question 28

In the following conditions outline the EEG patterns:

a) Alzheimer’s
b) Delirium
c) Partial epilepsy
d) Psychopathy

Answer 28

a) Alzheimer’s - loss of alpha
b) Delirium - some alpha and increased delta
c) Partial epilepsy - focal spike and wave
d) Psychopathy - posterior temporal slow waves
e) CJD - generalised fast waves and triphasic/biphasic waves
f) Metabolic encephalopathy - triphasic waves every 1.5-3 seconds

Question 29

Outline what MAO-A and MAO-B have a tendency to breakdown respectively?

Answer 29

MAO - A: Serotonin and Noradrenaline
MAO - B: Dopamine and Histamine and a range of phenylethamines

Question 30

What breaks down GABA?

Answer 30

Transaminase