SPMM Neurosciences Flashcards
What is the Stanford- Binet intelligence scale?
A test of intelligence consisting of 120 items can be used to assess children to adulthood
The Halstead-Reitan battery of tests was designed to improve reliability and accuracy of detecting
brain damage. It consists of 10 tests including trail-making test (visuomotor) and critical frequency flicker test (visual perception)
Is the Raven’s progressive matrix a test of non-verbal or verbal intelligence?
Non-verbal
Why is the Halstead-Reitan battery of tests helpful?
It can determine the location and effects of brain damage?
The Wisconsin Card sorting test is a good test of?
Executive functioning (DLPFC)
What does the paired-associative test assess for?
Verbal memory
What is the Rey-Osterith test
A test of visual memory - ppts are required to replicate a complicated line draeing
What does the Bender Visuo-Motor test assess for?
Screening measure for organic dysfunction
Name some visuospatial memory tests for animals?
Spiked maze test, T test and the morris water maze test
What is a sensorimotor gating test for animals
Latent-inhibition test
What does the light-dark box in animal models test for?
Anxiety behaviours
Name some neuropsychiatric diseases with trinucleotide repeats underlying genetic causes?
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
Phenylketonuria and Wilson’s disease are inherited in what genetic patterns?
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
What are association studies?
Identify a specific disease locus - find frequency of specific alleles at marker locus in cases compared to controls (not causal - association only)
Establishing a chromosomal location of disease locus is established by which studies?
Linkage studies
Name two study methods that identify the function of genes?
Transgenesis and gene targetting
Define the following
a) Silent mutation
b) Missense mutation
c) Nonsense mutation
d) Frame shift
e) Point mutation
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
What do the terms incomplete penetrance and variable expression mean?
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.
What does phenocopy refer to?
A phenotypically indistinguishable condition but without the genes - i.e. EPSEs from Parkinson’s but no genes
What does consanguinity do in Autosomal recessive disorders?
Increase the risk of inheritance
How does X inactivation occur?
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
What is unfavourable Lyonisation?
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.
Name some x-linked recessive disorders
Haemophilia A/B
Muscular Dystrophy
Androgen Insensitivity
Name two x-linked dominant disorders?
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
How is x-linked mental retardation classified?
Syndromic
- Fragile X
- Retts
Non-syndromic:
- Prader Wili
- Angelman
Outline some mitochondrial inherited syndromes?
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.
What is a dynamic mutation
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.
In the following conditions outline the EEG patterns:
a) Alzheimer’s
b) Delirium
c) Partial epilepsy
d) Psychopathy
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
Outline what MAO-A and MAO-B have a tendency to breakdown respectively?
MAO - A: Serotonin and Noradrenaline
MAO - B: Dopamine and Histamine and a range of phenylethamines
What breaks down GABA?
Transaminase
