Neuro extra stuff Flashcards
Describe the layers of the cerebellum
VI layers then White matter. VI to thalamus V to subcortical I-IV to cortex Thalamus to IV BS to all Cortex to I-IV
Parietal dominant function?
Speech (Brocas) and language
Logic - calculation
Problem solving
Motor skills
Lesion in anterior frontal results in?
Loss of personality Apathy Asociality Loss of social rules/ inhibition Euphoria without feeling so amoral
Temporal lesion
Memory e.g. people/ agnosias/ recognition
Speech
Parietal non dominant function
Emotion of language Music/art Visiospatial Body awareness Whole pucture
How are the left and right sides of the brain connected?
Corpus callosum and anterior and posterior commissures
Where does the interpretation of written and spoken word occur?
Wernicke’s area temporal lobe
Function of the angular gyrus?
Written word interpretation from occipital to Wernicke’s via angular gyrus
How does information pass from Wernicke’s area to Brocs’s?
Via the arcuate fasciculus
What are the types of memories and where are they stored? What feature of neurones allows this to happen?
Declarative- cortex, hippocampus and other cortical regions
Procedural - Cerebellum, basal ganglia, pre-motor cortex
neuronal plasticity
Storage of memory?
Intermediate = seconds allowing sense of present
Short = seconds to minutes = working memory
Transfers to long spontaneously or based on emotion, rehersal association.
Consolidation occurs via long term potentiation
How does memory formation occur? how do we forget?
Sensory info to sensory cortex. Then forms a loops with amygdala/ hippo/ thalamus/ basal forebrain/ pre frontal cortex and back.
Long term potentiation with NDMA glutamate receptors]
Result of the destruction of the hippocampus?
Antereograde amnesia
What is amnesia? Causes
Vascular interrution
Trauma
Infections, Vit B def
Retrograde in alzheimers
What is dementia
An aquires loss of global brain function that is significant enough to effect dailey function and quality of life
Loss includes intellect reason and personalit without loss in consciousness (with delerium there is)
Symptoms of dementia
Loss of progressive: Memory intellect personality behaviour speech movement (bradykinesia)
Causes of dementia briefly
Vascular (20%) ALzheimers Lewi bodies Fronto-temporal dementia Drugs
Protein and the deal with Alx
B amyoid deposition
Neurofibillary tangles
Prognosis 5 years
AGe and female = RF
Protein and the deal with lewi bodies
alpha synuclein prognosis 8 years REM bleep behaviour disorder fighting in sleep Delusions paranoia Later it resembled alzheimers dementia
Protein and the deal with fronto-temporal dementia
T Tau Prog = 8 years Behaviour and personality loss Semantic dementia (loss of meaning from language/ words) Progressive non-fluent aphasia Disinhibitions lOss motivation Lack of empathy Repetitive Convulsive behaviours Craving of sweet, fatty, alcohol, ciggs Loss of table etiquette
Describe early dementia
Loss of memory for recent events
Global distruption of personality
Gradual change in behaviour
describe intermediate dementia
Loss of intellect
Mood changes
Cognitive failure to learn
Describe late dementia
Reduction in self care
REstless wandering
Incontinence
Differentials for dementia
Delerium
Depression
What is normal pressure hydrocephalus and when does it occur
Symptoms = Dementia, incontinence and gait disturbance
Ventriculomegally (caused byu build up of CSF?)
Rare
Which layers does meningitis affect?
Leptomeninges = Pia and arachnoid
Causative organisms of meningitis
Neonates = Listeria Monocytogenes, E coli. 1-5 = H influenzae B (less now due to vaccine) 5-30 = N meningitidis >30 = S pneumoniae
What is encephalitis
Viral infection of brain parachyma.
Where does herpres virus often infect? result?
Temporal lobes
Epilepsy
Where does polio and rabies often occur?
Rabies = BS Polio = Spinal cord
What is perivascular cuffing
Aggregation of lymphocytes perivascularly in encephalitis
What is tomoplasmosis?
Toxoplasma gondii causes
Primary = flue, muscle aches, lymph nodes.
Later eye problems, seizures, coordination
How do Prions form and cause damage
Mutated proteins
Ingested proteins that then affect own proteins (post translational conformational change)
May be famililal or sporadic mutations.
Form very stable structures and aggregate and cause neuronal death- spongiform encephalopathies
Pressure in brain and coughing? How long can compensation occur?
0-10mmhg
coughing + 20
up to 60
Describe subfalcine herniation
Cingulate gyrus through falx cerebri. Ischemia of frontal and pariatal and corpus callosum
Describe tentorial herniatation
Uncus and parahippocampus through tentorial notch.
Damage to CN3 and occlusion of PCA and superior cerebellar arteries.
Can cause Duret haemorrhage in midbrain/pons
Describe tonsilar herniation
Cerebellar tonsils through foramen magnum compessing the brainstem - CVS apnoea
What are prodramal symptoms of raised ICP?
Intitial
Headache
VOmiting
Papilloedema
Acute phase of raised ICP
Pupil dilation
Coma (BS)
Possiibly hemiparesis from cerebellum
LAter = BS
Give examples of brain tumours
Meningioma bengin
Malignant = astrocytoma
Lymphoma
Most are mets (lung)
Difference between focal damage and diffuse damage in trauma
Focal = bruising and laceration- tearing of BV and contsions Diffuse = tearing of axons as they go between tissues of varying densiities e.g. white nad gray, pit stalk (DAI) leads to gliotic scarring and persistent vegitative state
Types of infarct in brain?
Regional e.g. named vesssel
Lacuna - less than 1cm affected with hypertension often in basal ganglia./
Difference between falx cerbri and falx cerebelli?
Falx cerebelli posterior
Falx cerebri superior
What makes MRI better than CT?
Less radiation
Multiple planes
Free from artifacts
Higher defintion
Describe PET scans and their use
Maps Biochemistry Positron emission tomography Uses positron emitting pharamceuticles e.g. L dopa Hypometabolic areas e.g. siezures Dementia
Decribe EEG uses
Electroencephalogram
Diagnose brain death
Epilepsy to select appropriate anticonvulsants
Describe electrophysiological-evoked potentials and types
Stimulation of nerve pathways and monitored and compared to background EEG
VER (visual evoked response) - optic neuropathy
Auditory
Somatosensory (SER) - peripheral nerve stim (can be used in neurosurgery)
What is electromyography and its uses
Needle into muscle to record electrical activity e.g. fibrillation potentials = hyperexcitability following dennervation or fasciculation potentials
T1 and T2 MRIs and water/ fat
WW2
Water white T2
T1 = fat white
How is taste different from flavour?
Flavour includes smell
Taste for pattern of stimulation of different neurones
How does tastes vary on tongue
All areas detect all types of taste: Sweet sour, bitter, salty and umami
Deficient sweet and salt at tip
Deficient sour and bitter at back
Emotiona components and outputs
Fornix, mammary body, anterior nuclei of thalamus, hippocampus.
Outputs:
Autonomic
RF
Cortex
Fronto-sensory cortex (emotional behaviour)
What is dioptic strength and what does it depend on?
1/focal length(m)
Measures strength of lens
Length changed by intraocular pressure (300-325mmHg)
Production and drainae of intraocular fluid? What happens if it goes wrong?
Produced by ciliary body and absorbed by Schlemm (venous sinuses)
Corrections for short and long sighted
Short = myopia = concave Long = hyperopia - convex
What is presbyopia?
long sighted with age
Progressive
Does accommodation in eye?
Ciliary muscle contracts to Increase convexity and allow nearer objects to be seen
What is the near point?
Closest point at which an object can be seen
What is visual acuity and what determines?
2 point discrim
Density and receptive fields
What is a pathological blind spot called?
Scotomata
How is colour vision tested?
Ishihara chart
Definition of trichonmats and dichromats
3 vs 2 cones
Colour deficit tyoes in trichromatis
Protanomaly red
Deutanolaly green
Tritanomaly blue
Loss of cones in dichromats
Protanopia red
Deutanopia green
tritanopia blue
Why do after images occur
Sensitises to opposite colour
See complementary colour
Descrube le fort fractures
1 = maxillary horizontal above teeth
2 = horizontal at nose and verical in miaxillar at orbit = separation of maxilla
3 Horizontal nose sphenoid and frontozygomatic arches/ suture
