Neurosciences 2 Flashcards
What is the name of the musle that raises the eyelid?
Levator palpebrae superioris
Which muscles have direct pulls from anatomical position?
Lateral rectus and medial rectus
What does the superior rectus do?
Pulls the eye up
adducts
medially rotates (intorsion)
What does the inferior rectus do?
It pulls the eye down Adducts Laterally rotates (extorsion)
What muscules are involved in looking down?
Superior Oblique and Inferior rectus:
Both depress the eye and so work as synergists
SO - Medially rotates and abducts
IR - Laterally rotates and adducts
(here they are acting as antagonists)
Which muscles are important when looking up?
The inferior oblique as superior rectus:
Acting as synergists as they both elevate the eye.
IO: laterally rotates the eye and abducts
SR: Medially rotates the eye and adducts
What conditions are needed for testing eyes?
Directly in front, eyes at same level, 2 arms lengths apart
which muscles are tested first and how do you test them?
Lateral and medial rectus. as their action is isolated.
move finger horizontally across their field of vision and look for medial and lateral eye movement
What muscle is tested after lateral/medial rectus and how are they tested?
Superior and inferior rectus.
First, abduct the eye so the muscles are in line with the angle of the gaze.
Move your finger vertically and look for elevation and depression of the eye.
In the abducted view this should only be using SR and IR.
How is the movement of superior and inferior rectus isolated?
Get patient to look laterally slightly so that the pull of superior and inferior rectus is pulling in line with the axis of the eye.
What is the last set of muscles to be tested?
the obliques
How do you test obliques?
First the eye must be adducted so that the muscles are in line with the angle of the gaze.
For superior look down and for inferior oblique look up.
Ensure that there is no rotation of the eye.
What is the snail shaped structure called?
Cochlea for hearing
What are the 3 looped structures in the hear called?
the semi-circular canals (vital for balance)
Anterior, Posterior and Lateral
What bone are the organs of balance and hearing in?
petrous part of the temporal bone
Where does the vestibulocochlea nerve leave the skull? and what does it leave with
with the facial nerve it passes through the internal acoustic meatus
What is the arrangement of the semicircular canals?
Three at 90 degrees to each other lateral anterior and posterior
this is so they can detect movement of the head in different planes
How do the semicircular canals sense movement?
When the head is moved the endolymph stays in place relative to the skull and deflects the cupula within which the hair cells are imbedded
What is the fluid in the semicircular canals called?
endolymph.
When are the semicurcular canals not working?
When you are not accelerating
What is nystagmus?
They have darting eyes
What can cause dizzyness
They can be from spinning or inflamation of the hair cells from the virus
What is the vestibulo-ocular reflex?
they eyes moving the opposite way to spinning
How can the vestibulo-ocular reflex be tested?
put cold water in the ear to cause convection currents and cause nystagmus slowly towards cold water
What is bottom up processing?
sensation
What is top down processing?
Perception
What is sensation?
A mental process resulting from the immediate external stimulation of a sense organ
What is perception?
The ability to become aware of something or understand something following sensory stimulation
What are the 5 types of perception?
Tactile, olfactory, Gustation, visual and auditry
What is a perceptual set?
They psychological factors that determine how you perceive your environment
What things make up our perceptual set?
Context, Culture, Expectations and Mood & motivation
What is gestalt proncipal?
Proximity common fate, continuity, similarity, closure, common region, symetry
What is a hallucination?
Experience involving he apparent perception of something not present
What is charles bonet syndrome?
When blind people have hallucinations
What can cause hallucinations?
Drugs, Sensory deprivation, stress, psychiatric illness(schizophernia, depression with psychosis)
What is involved with psychiatry treatment of hallucinations?
Social circumstances, medications, psychology
What type of wave is sound?
compression and rarefaction transverse waves
What qualities does sound have?
High pitch/frequency amplitude is volume
What is the frequency range of a human?
20Hz-20kHz
What is the variability of hearing sound ranges and speech
hearing a range of sound is possible but speech is heard in a small range
How loud is too loud and quiet?
10dB pain is around 130dB
What are the components of the auditory system?
The outer ear middle ear and inner ear
What are the conduction mediums of the 3 sections of the ear?
Outer- air, middle-air, inner-fluid
What are the names of the three ossicles?
Malleus incus stapes
What is the technical term for the ear?
Pinna
Where is the outer ear?
From the Pina to the tympanic membrane
Where is the middle ear?
The area around the ossicles
From the tympanic membrane to the oval window
What is the area of the inner ear?
Around the cochlea and semicircular canals
What is the structure of the external ear?
Made of cartilage, and 6 hillocks
What is the purpose of the ear?
to direct sound down the ear canal
What are the ridges of the ear?
Helix, antihelix, tragus, conchal bowl and triangula fossa
What is the composition of the ear canal?
1/3 cartialage and 2/3 bone
What is the structure of the ear drum?
Tympanic membrane, 3d structure inferior is further away. Malleus is touching it and can see incus sometiems.
What are the two sections of the eardrum?
Pars flacida top third
bottom third pars tensa
anulus around it
bottom part of the ear has 3 layers
Which part of the tympanic membrane is more prone to dammage?
The pars flaccida. as only has endoderm and ectoderm not fibrous mesoderm
What is in the middle ear?
Bones- malleus, incus and stapes
Muscles such as tensor tympani and stapedius
Tubes- eustachian tubes
What bone is attached to the tensor tympani?
The malleus
Which bone is attached to the stapedius?
the stapes
Which nerve innervates the tensor tympani?
Mandibular branch of the trigeminal nerve
Which nerve innervates the stapedius muscle?
facial nerve
What is the action of the muscles in the ear?
Reduce damage of loud sounds by dampening of the sound. tensor tympani is slightly voluntary to remove chewing sound
What is the purpose of the bones?
It turns the sound in the air into fluid
usually 99.9% is lost.
acoustic impediance. they increase force amplify it like a lever 1
What is the eustatian tube?
Ventilation of the middle ear space and drainage of secretion
What is the labyrinth?
Another name for the semicircular canals
How many turns does the cochlea have?
2.5
What are the two openings in the ear?
The round window and the oval window. the oval window is for the stapedius
What are the three compartments of the cochlea?
Scala tympani, Scala media and scala vestibuli
What is endolymph and where is it?
In the scala media and has high potassium
Where is perilymph and what is is?
Sodium rich potassium poor it is in the scala vestibuli and scala tympani
how are the three compartments arranged?
The scala vestibuli is attached to the oval windo, at the tip of the cochlea is the helicotrema and changes to the scala Tympani and between the two is the scala media
How does sound enter the cochlea?
The stapedius moves the membrane of the oval window and transfers the waves into the perilymph
What are the boundaries of the scala media?
the reissners membrane to tthe scala vestibuli and basilar membrane and organ of corti in the scala tympani
What is the tectorial membrane?
a large sheet of tissue attached to the hair fibres
What is the importance of the basilar membrane?
At the base its narrow and stiff and wide and floppy at apex. the base is good for high pitch sounds the apex is good for lower pitch sound
How is the sound translated to nerve impulses?
Basillar membrane moves up and down against the tectorial membrane which is fixed. the inner and outer hair fibres connect the basillar membrane to the tectorial membrane.
What do the inner hair cells do?
sense the movement and do mechanical transductions
What do the outer hair cells do?
fine tune the sound by stiffening the basilar membrane at the wrong frequency
What is the importance of the nerve in the inner hair cells?
There are afferent and efferent nerves
How is the movement of the hair cells transduced into nerve impulses?
The endolymph is high in potassium and lets it in when the stereocillia move. it causes depolarisation and voltage gated calcium chanells open to release neurotransmitters
How is the pitch encoded?
The frequency comes from the location of stimulation of the basilar membrane
How is the intensity encoded?
How many nerves are firing and firing rate
how does the signal get to the brain from the ear?
The sensory fibre stimulates the spiral gangleon that contributes to the cochlear nerve and then into the brain
What happens to sound in the brain stem?
Cochlea Eight nerve nucleaus superior Olivary complex lateral Lemniscus and the Inferior colliculus and crosses. medial geniculat body ECOLI
How is sound localised?
The difference between signals from the right and left ear this happens in the superoior olivary complex. from coincidence on internerons
What are the types of hearing loss?
Defective outer/ middle ear= conductive hearing loss
Defective inner ear= sensorineural hearing loss
Where do most of the cranial nerves come from?
The brainstem apart from optic and olfactory
What divides the frontal and parietal lobes?
The central sulcus
What divides the frontal and temporal lobes?
the silvian fissure or lateral sulcus
Which part of the brain exits the foreman magnum?
the medulla oblongata
what separates the parietal and occipital lobes?
Parieto-occipital sulcus on medial area of the brain
What are brodmans areas?
areas based on histology, separated into sections
How is the frontal lobe strucutred?
There are 3 main giri usually
Where is the hand motor cortex?
In the omega shaped area of brain
Where is brocas area?
in front of the central girus above the temporal lobe
Where is the cingulate girus?
Around the outside of the corpus callosum
What are the regions of the corpus callosum?
Rostrum, genue, body and splenium
Where is the fornix?
Runs under the corpus callosum into the mamillary bodies
Where is the calcarine sulcus?
The primary visual cortex medial area of occipital lobe
How can the temporal lobe be divided?
Superior middle and inferior giri
What is the shape of the ventricles?
The lateral ventricles, 3rd ventricle, and 4th ventricle
What are the exit points for CSF?
Foramaen of luska and majendie
What are the areas of the lateral ventricles?
anterior/frontal horn, posterio/occipital, lateral/ temporal
Where can CSF collect?
Prepontine system, interpeduncular system, supracella system, quadrigeminal system, cisterna magna
Why are the CSF systems important?
To see where blood collects
What is the corona radiata?
Fibres from the centre of the brain to be the descending tracts
What colour is CSF on MRI?
Black on T1 White on T2
What is the colour of the brain on T1 weighted scan?
Grey matter is grey white matter is white
What is stress?
It is either psychological (mental or emotional strain or tension resulting from adverse or demanding circumstances) or physiological (sensory, emotional and subjective experience associated with potential damage of body tissue and bodily threat
What is Eustress?
Good stress is beneficial and motivating to strive towards a goal
What is Distress?
Negative stress that is damaging and harmful
Is stress physical or mental?
Both has affects in both systems
What is acute stress?
Short-lived response to a novel situation experienced by the body as a danger
What is chronic stress?
Arises from repeated or continured exposure to threatening or dangerous situations
What are some causes of chronic stress?
Physical illness, disability and pain, physical or sexual diseases, poverty, unemployment, bullying caregiving
What is General adaptation syndrome?
There are three phases to stress response. Alarm then adaptation, and finally exaustion mental and physiological
What are the five elements of human stress response?
Biochemical, physiological, behavioural, cognitive and emotional
How is the stress response mediated?
autonomic nervous system( sympathetic-adrenal medullary) and hypothalamo-pituitary axis
What is the sympathomedullary pathway?
Hypothalamus activates the adrenal medulla. this produces adrenaline and noradrenaline into the bloodstream, this prepares for floght or flight and reinforces the sympathetic activation
What is the pituatary adrenal system?
Higher brain centres stimulate the hypothalamus to release corticootrophin, the pituitary galsnd releases adrenocortocotrophic hormone andd the adrenal cortex releases corticosteroids which cause changes in the liver and the immune system is suppressed
What are the biochemical stress responses?
Glucocorticoids(cortisol) catecholamines( adrenaline noradrenaline) this is part of inflamation and immunre response in chronic low inflamation and partial supression
What are some of the physiological stress responses?
Headache, chest pain, stomach ache, musculoskeletal pain, low energy, loss of libido, colds and infections grinding teeth
What are the behavioural responses to stress?
Easily startled, change in appetite, hard to concentrate, avoiding tasks, weight change, nail biting fidgeting and pacing, sleep disturbances, withdrawal
What are the cognitive responses?
Constant worrying, racing thoughts, fogetfulness and disorganisation, inability to focus, poor judgement, being pessimistic, learning
What are the emotional responses?
Depression sadness, tearfulness, mood swings, irritability, restlessness, aggression, low self-esteem, boredom and apathy, feeling overwhelmed, rumination, anticipation and avoidance
What is allostasis?
refers to how multiple complex systems adapt collectivels it is fragile and decompensation can happen quickly
What is allostatic load?
refers to cumulative exposure to stressors and can lead to absorption
What are the links between stress and illness?
Cancer survival, skin conditions, sexual dysfuncction Medically unexplained symptoms,, obesity, CVD GI problems
What is evolutionary psychiatry?
the application of modern evoultionary theory to understand health and disease looks at diseases of civilisation. It answers why questions
How can some psychiatry be linked to evolutionary processes?
we have mental function linked to hunter gatherer type living but we have now deviated from this which leads to problems it is a species perspective not individuals
What is the pleistocene environment?
Environment of evolutionary adaptation
Why is it important to look at evolution in psychiatry?
could offer theories about substance misuse, borderline states and schizophernia, bipolar disorder, the dementias and affective disorders as well as childhood neurodevelopmental disorders
What are tinbergen’s questions?
Mechanism how does a behaviour occur?
Development how does this arise in an individual?
Evolution how does this behaviour arise in the species
Adaptive value why is this adaptation valuable
what are pathways that mediate evolution causing disease problems
Mismatch, exposure to evolutionarrily mismatched environments
Life history: reproductive age ageing menopause
Excessive defence mechanisms: pain cough are beneficial for survival but not enjoyment
Co-evolutionary considerations: other diseases evolve
Constraints: limitations for natural selection
What are some evolutionary symptoms that psychiatry aims to tackle?
Pain sickness illness behaviour, anxiety depression OCD, feer lethargy fatigue, nausea, itching, sneezing
What is dunbar’s number?
150 number of people you can maintain a stable relationship with.
How can schizophrenia be potentially explained by evolution?
Brain designed to be hunter gatherer in small tribal band know friend from foe. our society mixes this up can lead to stress and lead to it
what is compassion focused therapy?
Based on evolutionary neruoscience and psychological. there are 3 types of regulation threat protection, drive excitment, contentment, soothing and social safeness. focused on facilitating development of the compassion theory
What is the receptive field of the eye?
The area that is sensitive to light
What is retinal encoding?
When rods and cones feed into retinal ganglion cells
What are parvivellular RGCs good for?
Low-contrast High linear spatial resolution
What are Koniocellular RGCs good for?
Blue- yellow colour opponency
What are magnocellular RGCs?
High contrast, Low resolution, motion detection and colour blind
What is the island of vision?
There is a very small part of vision that is very sensitive
What is the optic chiasm?
a structure that fuses some of the inputs of the eye to allow integratio of information from both eyes
What is the lateral geniculat nucleus?
The nucleaus in the brainstem for visual informaton. synaps of first order retinal ganglion cells to 2nd order neurons. there are layers for the three types or retinal ganglion cells
what is the dorsal stream pathway for vision?
where pathway
What is the ventral stream pathway
What pathway
How is depth percieved?
Familiar size objects can be judged small objects are assumed to be smaller, linear perspective occlusion, shadows and illumination, motion parallax can be used too
How is colour percieved?
Colour isnt a constant it is taken with context of what is around the object
Why do we move our eyes?
Clear vision of an object requires that its image be held teadily on the retina clearest when focussed on the retina, these aid vision
What is vestibular eyemovemnet?
Holds images of the seen world steady on the retina during brief head rotations or translations.
What is visual fixation?
Holda the image of a stationary object on the fovea
What is optokinetic eye ovement?
Holds images of the seen world steadt on the retina during sustained head rotation
what is smooth persuit eye movement?
holds the image of a small moving target or oposite way round with movement
What is nystagmus quick phases?
Reser the eyes during prolongued rotation to direct gaze to oncoming scene
What are saccades eye movements?
Bringing objects of interest into the fovea
What are vergence eye movements?
Moves the eyes in opposite directions so that images of a single opject are placed or held on the fovea of each eye
What areas of the brain are involved in eye movements?
THe primary visual cortex
What are the roles of saccades?
Searching the environment, reflexive to noise or touch, voluntary to look at specific things can be surpressed
What areas are involved with persuit saccades?
Parietal cortex,
Are the cranial nerves PNS or CNS?
PNS but optic and olfactory are more CNS
What are the sensory functions that nerves can have?
Somatic, general sensation and special sensation also autonomic sensations
What are the motor functions?
Muscle contraction conscious and subconscious for non skeletal muscle glands
Which cranial nerves carry parasympathetic fibres?
1937 = 10,9,7,3
What is CNI?
olfactory
Which nerve is the olfctory?
CNI
Where does CNI leave the skull?
The cribiform plate
What does the olfactory do?
Sense of smell. it goes directly to the cortex
What is special thing about the sense of smell?
it doesnt pass through the thalamus
How much of smell crosses sides?
15%
How can you test olfaction?
Get something smelly and see if they can guess it
What can damage the olfactory nerve?
Sudden deceleration severing nerves
What is cranial nerve 2?
Optic nerve
What is the optic nerve?
CNII
What does the optic nerve do?
Vision sense
What is the exit point of the optic nerve?
the optic canal
How can you tell if you have intercranial hypertension?
if the optic disk is swolen
How does image from the right eye travel?
the nasal retina crosses through the other side the temporal side stay the same side.
Where do thefirst neurons synapse?
The lateral geniculate nucleus
What happens when the right optic nerve is cut?
Blindness in the right eye only
What happens if you damage the right optic tract?
You lose the right side of vision from both eyes left sided homonomous hemianopia
What happens if there is damage to the optic chiasm?
both eyes cant see the temporal regions bitemporal hemianopia
What happens with damage to the temporal lobe on the right?
The optic radiation is affected and you cant see the upper area.
What happens in the pretectal nucleus superior colliculus in vision?
Fibres from the optic nerve synapse to there and leving to the edinger-westphal nucleuse to supply the pupil through the 3rd nerve
How can you test the optic nerve?
Visual fields, pupil reflexes, visual acuity, fundoscopy.
When testing the visual acuity what else are you testing?
The cornea the lens and humours of the eye as well as the optic nerve
How should the optic disk usually move when you move left or right?
the lighter part is a cup and the lighter part moves in the same direction as the head
What is the optic disk like when its swollen?
The lighter part moves to the oposite side that you move your head
How do you test the pupil?
Shine it into both the eyes and watch for reaction in both eyes.
look for constriction on accommodation
What does sympathetic innervation to the eye do?
Lift the eyelid and dilate the pupil
What is the difference with the occulomortor nerve?
It has parasympathetic and controls most muscles of the eye and does constriction of the pupil
What nerve is the occulomotor nerve?
The CVIII
Which nerve is CNIII?
Occulomotor
Which nerve is CNIV
trochlear
Which nerve is the trochlear?
CNIV
What does the trochlear nerve do?
Innervates the superior oblique muscle
What nerve is the abducens?
CNVI
What is CNVI?
The sixth cranial nerve abducens
What does the abducens nerve do?
Innervates lateral rectus
Which muscles does CNIII do?
superior rectus, inferior rectus, medial rectus, inferior oblique, and parasympathetic to the pupil and focus the lens
Where does the third cranial nerve exit the brain?
Through the interpeduncular fossa
Where does the fourth nerve leave the brain?
The posterior below inferior colliculus
Where does the sixth cranial nerve leave the brain?
The bulbopontine fissure
Where does the occulomotor nerve leave the skull?
The superior orbital fissure
Where does the absucens nerve leave the skull?
The superior orbital fissure
Where does the Troclear nerve leave the skull?
The superior orbital fissure
Which nerves pass through the superior orbital fissure?T
The occulomotor, the trochlea, the abducens
Which nerves pass though the cavernous sinus?
CN III oculomotor 4th trochlear parts of trigeminal opthalmic maxillary and the abducens nerve
What happens with the third cranial nerve pallsy?
Down and out from lateral rectus and superior oblique
What happens with trochelar nerve pallsy?
Double vision when looking down the stairs
what happens with abducens nerve problems?
Cant look laterally
What does the trigeminal nerve do?
Sensation to the face and mouth muscles
What nerve is the trigeminal?
CN V
Which nerve is CN V?
the trigeminal nerve
what are the three divisions of the trigminal nerve?
opthalmic maillary and mandibular
Where does the opthalmic division of the trigeminal sensation include?
Cornea sclera alont top of nose up to top of head and the frontal sinuses and ethmoid
Where does the maxillary division of the trigeminal sensation include?
just above eyes laterally under eyes and above the mouth, roof of the mouth upper teeth, maxillary sinuses
Where does the mandibular division of the trigeminal sensation include?
Lower mouth muscles of mastication floor of the mouth. normal sensation to the anterior two thirds of the tongue lower teeth
Where does the trigeminal nerve exit the brain?
The edge of the pons
Where does CN VII exit the brain?
The medulla
Where does CN VIII exit the brain?
The pontine medulla fissure
Where does CN IX exit the brain?
The medulla
Where does CN X exit the brain?
The medulla
Where does CN XI exit the brain?
The medulla
Where does CN XII exit the brain?
The medulla
What nerve is the facial nerve?
CN VII
What is CN VII?
Fascial nerve
What does the facial nerve do?
the muscle of the face for expression and stapedius, it also does lacrimal submandibilar andsublingual salivary glands
also the sopecial sense of taste buds of anterior two thirds of the tongue
What can be a sign of 7th nerve palsy?
hearing sound too loud or better
How many origins are ther of the facial nerve?
3 separate ones
What are the superficial branches of the facial nerve?
Temporal zygomatic buccal mandibular, cervicle and posterior. Splits inside the parotid gland
Where does the cranial nerve 7 leave the skull?
the sylo-mastoid foramen
What is clinically relavant about the control of the facial muscles?
The lower half of the faces only has contralateral innervation and the top half has bilateral. forehead sparing
What can lead to facial palsy?
Bells palsy virus, fracturs to the temporal bone, middle ea infections tumouts of parotid
What does the vestibulorcochlear do?
It carries sound signals and balance
Which nerve is the 8th nerve?
Vestibulocochlear
Which nerve is the vestibulocochlear?
the CN VIII
What is the utricle and saccule
Urticle detects acceleration in the horizontal plane
Saccule detects acceleration in the Verticle plane
Where does the vestibulocochlear nerve pass through the skull?
The internal acoustic meatus
How can you examine the cochlear directly?
By placing a vibrating tuning fork on the bone
What is cranial nerve 9?
Glossopharyngeal nerve
Which nerve is the glossopharyngeal nerve
the 9th nerve
Where does the glossopharyngeal nerve leave the skull?
Jugular foramen
What does the 9th nerve do?
motor to stylopharengeas muscle, parotid gland secretions, sensation of skin of external ear, touch to posterior third of pharynx and eustation tube, taste to the posterior thrid of the tongue also carotid bodies
What is cranial nerve X?
the vagus
What nerve is the vagus?
X
What does the vagus nerve do?
Muscle of pharynx and larynx, autonomic motor to abdomen, sensory to external ear, sensory for parynx larynx aortic arch and abdominal viscera, taste to epiglottis
How can the vagus and glossopharengeal nerve be examined?
To look at the quality of their voice look at the soft palate
What is the acessory nerve?
CNXI
What is CN XII?
The acressory nerve
What does the acessory nerve do?
Sternocleidomastoid and trapezius muscles
What is special about the acessory nerve?
They send signals from the spinal cord up the foramen manum then comes back through the juglular foramen
What is thelink between CN 10 and 11?
Can have larynx linked to it
Which nerve is the hypoglossal?
CNXII
Which nerve is CNXII?
Hypoglossal
Where does the hypoglossal nerve exit the skull?
The hypoglossal canal
What does the hypoglossal nerve do?
intrinsic muscles of the tongue and extrinsic
What is pain?
An unpleasant senory and emotional experience associated with the actual or potential tissue damage or described in terms of such damage
What is nociceptive pain?
Pain that arises from actual or threatened damage to non-neural tissue and is due to the activation of nociceptors
What is neuropathinc pain?
Pain caused by a lesion or disease of the somatosensory nervous system
What is nociplastic pain?
Pain that arises from altered nociceptive despite no clear evidence of it being one of the others
What is allodynia?
Pain due to a stimulus that shouldn’t provoke pain
What is dysesthesia?
An unpleasant abnormal sensation, whether spontaneous or evoked
What is hyperalgesia?
Increased pain from a stimulus that normally provokes pain
What is hypoalgesia?
diminished pain in response to a normal painful stimulus
What is hypoesthesia?
Decreased sensitivity to stimulation, excluding special senses
What is acute pain?
Pain for less that 12 weeks
What is chronic pain?
Pain beyond 12 weeks, longer than tissue healing
What can chronic pain be split into?
cancer and non-cancer pain
What are nociceptors?
They are sensory neurons that are found in any area of the body that can cause pain either externally or internally
What areas are nociceptors found?
Skin cornea mucosa, organs, joints muscles
Where are the cell bodies of the nociceptors?
In the dorsal root ganglion or trigeminal ganglion for the face
What is the pain pathway?
Receptors in the site are activated, it enters the dorsal rood where the ganglion is, then enters te spinal cord in the dorsal horn and crosses to the contralatral side to the spinothalamic tract which runs to the thalamus, then to the somatosensory cortex
What can switch on the pain impulse?
Lots of cytokines and inflamatory markers
What are the types of pain fibres?
A delta fibres and C fibres
What are the fastest fibres?
A delta myelinated
What are the C fibres?
Pain mechanical thermal and chemical that are non myelinated
What are A alpha fibres?
Proprioceptive myelinated firbes
What are A beta fibres?
Touch fibres that are myelinated
What is A delta firbes?
pain mechanical and thermal myelinated fibres
Describe the stpinal thalamic path?
2nd order neurons are from th spinal cord the axons decussate at higher level to where they enter and then are in lateral or anterior parts
What is the role of the thalamus in pain?
It relays the signal to other areas and reciprocates connections to cortex
What is cortical reorganisation?
When a limb is lost the sensory cortex is remapped and signals move the homunculus that can cause pain
What is the insular cortex involved in pain?
perception and motor control with self awarness and interpersonal things the degree of paincan be managed here
What does the cingulate cortex do in chronic pain?
linked with the limbic system and is associated with pain interpretation
What does the amygdala do in chronic pain?
Plays a key role in emotional responses and interpretation of pain
What are the symptoms of depression?
Biological: poor sleep, poor appetite, reduced libido, poor concentration
Cognitive: worthlessness, Guilt, Hopelessness, Suicidal thoughts
low mood low energy
What is the role of stress?
Experience, genetics can lead to body/ mind being susceptible to stress
What is the link with depression and HPA axis?
High levels of cortisol stress hormone over an extended period. they have enlarged adrenals and pituitary and the negative feedback is not as good
What is a causitive factor in HPA function?
Poor care when young means have less control of HPA
How does stress damage the brain?
Neurotoxic steroids, neuro-vulnerability, reduced neurogenesis
Which part of the brain is dammaged more in depressions?
Medial prefrontal cortex for emotional states, and dorsolateral prefrontal cortex for working memory problem soloving,
Hippocampus
Frontal lobes
How do anti-depressants work?
They boost serotonergic and adrenergic transmission. increase glucocorticoid expressant gene expression in the brain through G coupled proteins. to help regulate HPA
How can depression be explained by evolution?
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What is the default mode in the brain?
When you’re not thinking about things the areas of the brain that are active.
What is the role of the default mode network relavance to depression?
depression is linked with thinking about yourself going in circles
What happens in default mode network?
Autobiographical details, self reference, thinking about others social judgements
What is the idea of surprise and the brain?
It creates models to try and reduce surprise. which can lead to depression or other mental health diseases
What is the treatment for depression?
Mindfulness reduces default mode network
What is involved in the papez circuit and memory?
Amygdala, hippocampus, fornix, cingulate gyrus, mamillary hodies hypothalamus
What is the limbic system responsible for?
memory and emotions
What is the hippocampus responsble for?
The formation of new memories. not new skills, working memory, emotional memory
Which area of the brain is involved in working memory?
Prefrontal cortex
Which area of the brain is involved in emotional memory?
Amygdala
Which area is involved with conditiond reflex memory?
The cerebellum and others
What is the hypothalamus like?
Lots oc nuclei that are involved with thirst hunger temperatrue sleep sexual urges endocrine influences
What are the mamillary bodies involved with?
The laying down of new memories
What areas of the brain are involved with movement?
Cerebellum, Basal ganglia, motor cortex, brainstem motor nuclei, spinal cord
What initiates motor control?
The upper motor neurons in the cortex
Where are lower motor neurons?
in the spinal cord and to periphery.
Does training change the number of fibres?
no it just changes the area of each fibre
How are large range and strengths of movement achieved?
Antagonistic arangements, recruitment so muscles fibres can be gradually activated to get the required force
What are alpha motor neurones?
they are muscle fibres to muscles that are controlled voluntarily
What is a motor unit?
The since alpha neuron and all the muscle fibres it innervates
Are motor units always the same size?
It varies depending on the use of the muscle
What is the motor pool?
all the motor neurons that innervate a single muscle. they contain alpha and gamma motor neurons,
What are the regions of the spinal cord?
White matter grey matter grey in the middle, ventral and dorsal horns
Where does sensory information enter the spinal cord?
Dorsal route
What do the golgi tendon organs do?
They sense tension
What do muscle spindles sense?
length of the muscles
What are golgi tendon organs like?
They have sensory fibres 1b that exit from the tendon and are involved with inhibiting muscle tension when it risks dammage
Why are muscle spindles important?
they can activate muscles when they are at risk of hyper movments and involved in proprioception to correct small movements
what are another name for muscle spindles?
intrafusal muscle fibres
what type of nerve innervates the intrafusal muscle fibre?
Gamma motor neurons
What is size principal?
The smaller motor units are recruited first then bigger after.
Which areas of the brain are involved by speech?
The primitive cortex can be controlled by the cortex though
Where do motor commands originate?
In the grey matter of the cortex. and often down to the spinal cord
What does the cerebellum do in movement?
it corrects movements and modulates the effects off the motor signals. also involved in motor learning and emotional processing
What do the basal ganglia do in movement?
It receives cerebral cortex information and imhibits the condiction of the signals to motor neurons.
involves a double negative system. it inhibits everything and then disinhibits the selected activity
What is the use of the hominculus?
It can help identify symptoms but it is overlapping and slightly variable
Where do the descending projections go?
through the medulla in the primary pyramid and decussates.
What is a pyramidal tract and why is it called that?
The cortical nerve cells which cary motor singals down from the cortex. they are pyramidal neurons
What are the important tracts in motor control?
The dorsolateral tracts and ventromedial tracts
What is the path of the dorsolateral corticospinal tract?
From the cortex down through the medullary pyramid and it decussates below that into the spinal cord
What is the pathway of the dorsolateral corticorubrospinal tract?
From the cortex through the red nucleus, then decussates to the contralateral side before the pyramids
What is the pathway of the ventromedial corticospial tract?
From the cortex to thespinal cord on the ipsilateral side used for the trunk
What are the similarites between dorsolateral tracts and ventromedial tracts?
Both direct corticospinal route, both alternative routes via red nucleaus or tectum , dorsolateral does contralateral and other does both sides, dorsolateral does distal muscles other does proximal
What are involved in the basal ganglia?
Globus pallidus, caudate, putamen,
What is the disinhibitory mechanism in the basal ganglia
at rest the caudate is resting and globus palidus fires which inhibits the thalamus and motor cortex. if you activate the caudate from substantia nigra. this disinhibits the globus pallidus and allows the thalamus and motor cortex to act
Other than motor actions, what is the basal ganglis used for?
It could be involved in limbic processing
What happens in cerebellum disfunction?
Intention tremmor, voluntary movement is jerky and loses fluidity, oftem seem drunk
Where does the cerebellum get signals from?
motor cortex, somatosensory areas, proprioceptive spinal informations, vestibular information from ear
What is grey matter?
neurones and processes, less myelinates
What are association fibres?
Anteior to posterior fibres
What are commissural fibres?
that connect the two sides
What are projection fibres?
Ones that connect vertically in the brain
Where is the insula?
inside the lateral fissure
What are the frontal lobes involved with?
Higher level functioning such as motor, problem solving memory judgement impulse control, higher cognitive function and language
How do you locate the central sulcus?
Find 2 giri and 3 sulci. deepest continuous sulcus.
What order is the motor homunculous in the human from corpus callosum to lateral fissure.
genitals foot leg shoulder elbow wrist hand fingers eyes nose face lips jaw tongue pharynx
What is the temporal lobe involved with?
Semantic processing the meaning, memory language and primary auditory cortex
What is the parietal lobes involved with?
In dominant perception language maths, non dominant visuospatial function
What is the occipital lobes used for?
Mainly visual
What is a structure around the occipital lobe?
striate cortex, stria of gennari, the calcarine fissure
How many layers of cells are there in the neocortex?
6
What is parcelation?
Dividing the brain into many parts like brodmann areas
What is asymetries of the brain?
left occipital larger right frontal
What is the dura mater?
Contains lots of collagen, it is closely associated witht he periosteum
What layer is under the dura mater?
The arachnid mater where the blood vessels lie in the surface of the brain
Where is CSF in the brain?
between pia mata and arachnoid mater
Where is the pia mater?
It is very close to the surface of the brain
where are areas that the dura mater dives down?
Falx ceribri between the two hemispheres, tentorium cerebelli between cerebrum and cerebellum and the falx cerebelli between the cerebellar hemispheres
where is the superior sagital siunus?
In the falx cerbri at the top
Where is the inferior sagital sinus?
In the falx ceribri lower down
What are arachnoid cisterns
area between arachnoid and pia mater where CSF can collect
What is the structure of the autonomic nerve?
they are often very small and fine fibres
What is different in the autonomic to somatic in terms of synaoses?
There are ganglia after they leave the CNS to control things in the somatic its got no synapses after the spine
Is the autonomic system stiumulatory or inhibitory?
Both
What are the neurotransitters used in the autonomic motor neuron pathway symopathetic?
first ganglion is autonomic ganglion which is acetyl choline nicotinic receptors, then at the effector is noradrenaline with adrenergic receptors
Which fibres in the autonomic nervous system are normally myelinated and which are normally unmyelinated?
preganglionic - myelinated
post ganglionic - unmyelinated
What nerves are involved in the parasympathetic?
1937, CN X,IX,VII,III and sacral outflow
What nerves are involved in sympathetic?
they sympathetic chain ganglia with nerves from 3 cervical 11 thoracic and 4 lumbar and a few sacral T1 to L2
What are the roles of the autonomic nervous system?
thermoregulation, exercise digestion, sexual function
What can the sympathetic nervous system do?
Adrenaline release, increased BP, glucose release pupils dilate, chest pain heart pumps faster, sweating, shallow breathing,
What can overstimulation of sympathetic stimulation by stress do?
High BP dammages things causes Heart attack angina stroke, more clogging
What often is wrong in text books?
Sympathetic does ejaculation, parasympathetic erection, also does vasodilation
What are the neurotransmitters used in the autonomic motor neuron pathway parasymopathetic?
first ganglion is autonomic ganglion which is acetyl choline with nicotinic receptors, then at the effector is acetylcholine with muscarinic receptors
What are some of the parasympathetic ganglia in the head?
Cilliary, submandibular glands, otic ganglion
where is the origin of the sympatetic nerves?
The brainstem
What are the exit pathway of the sympathetic nerves from the spinal cord?
The white rami communicates to enter the sympathetic chain post ganglionic is after that lateral grey horn
What is the aortic plexus?
It is involved with sensing of BP
What happens when the adrenal medulla is stimulates by the sympathetic nerve system?
releases adrenaline to amplify the signals to the body
What is the enteric nervous system?
separate system that can function on its own in the body
What are the receptors for noradrenaline?
Alpha 1 or 2 in blood vessels, beta 1 in heart 2 bronchi 3
What are the carotid receptors?
in bifurcation of the carotid, has chemo receptors sensitve to oxygen and pH and also mecano receptors for stretch
Which nerve caries signals from the carotid bodies?
9th CN
What is a primary ANS isorder?
Where the signals are not being sent properly
What is a secondary disorder of the ANS?
when the nerves carrying the system are not functioning diabetes guillain barre syndrome HIV Chagas disease
What are symptoms of ANS disorders?
Postural hypertension, supine hypertension, tachycardia bradycardia and fainting, sweating excessive thermoregulation, GI problems
What makes up the basal ganglia?
Striatum (putamen, caudate), globus pallidus, subthalamic nucleus substantia nigra
Where are the basal ganglia?
Inside is the globus pallidus, then striatum outside
What makes the internal wall of the lateral ventricles?
the caudate
Which dysfunctions are related to the basal ganglia?
Parkinsons, Huntingtons, Dystonia, tourettes syndrome, OCD ADHD,cerebral palsy wilsons disease
What are the symptoms and reason for parkinsons disease?
increased muscle tone, reduced movements. not enough dopamine
What are the symptoms and reason for huntington’s disease?
decreased muscle tone, overshooting movements too much dopamine
What is the synthesis of dopamine?
L-tyrosine, L-DOPA dopamine then norepinephrine, epinephrine
What is produced in the substantia nigra?
dopamine
How can you tell someone has parkinson’s from their brain?
Reduces size of substantia nigra
How can you tell someone has Huntingtons’s from their brain?
extra substantia naigra
What is reduced in size in huntingtons disease?
The caudate nucleus
What is the function of the basal ganglia?
regulation of movement signals come from the cortex go back to cortex and then result in movement
What does dopamine do?
It allows movement via the substantia nigra
What does GABA do?
Inhibits movement from the striatum
What are the symptoms of Parkinson’s?
Brady/Akinesia- struggle doing up buttons writing small and difficulty walking
Tremor- resting tremor
Rigidity- pain and hard to turn in bed
What are treatments for Parkinsons?
Increase availability of dopamine reduces acetylcholine L-DOPA but doesn’t treat underlying cause
What stimulation can be used in Parkinson disease sufferers?
Stimulation of the subthalamic nucleus
Why does stimulation of the subthalamic nucleus reduce symptoms of PD?
lesioning of the nucleus means it cannot inhibit the struiatum and signals reach the thalamus
What are the symptoms of Huntingtons?
Chorea, dementia psychiatric illness, personality change
What causes Huntingtons?
repeat of sequence, that is normal
What is hemiballism?
due to lesion in the subthalamic nucleus
What is the lentiform nucleus?
the putamen and globus pallidus
What is the ventral striatum?
Below the anterior commisural fibres
What separates the caudate from the putamen?
The internal capsule(anterior limb)
What separates the putamen and the globus pallidus from the thalamus?
The internal capsule(posterior limb
Where is the sub thalamic nucleus?
beneath the thalamus
Why is globus pallidus dark on T2 weighted scan and red nucleus?
Has iron in it
How does fMRI work?
Uses blood oxygen level dependant contrast, done repetitions analysis by software
How can fMRI be useful clinically?
Looking at how much they can remove in surgery
What are the three main hazards present in an MR environment?
Projectile effect
Heating
Implants
What is the MRI environment?
The room where the MRI scanner is
What are the areas of scanners?
Controlled Access areas and MR environment both access cardrestricted
When is the MRI machine turned on?
All the time
What cannot go into the MR environment?
Money bank cards, metal items
What are some physiological effects?
Peripheral nerve stimulation, vertigo nausia and its loud
What are the three safety labels?
MR safe objects that are non metallic non magnetic and non conductive
MR conditional meaning it is treated under certain restrictions
MR unsafe cannot go in the room
What is the deal with implanted devices?
Some are safe others are not
What is the responsibility of the referer?
To notify of the problems the patient has and any potential risks
What can persistant pain effect?
Ability to work, activities social daily, satisfaction enjoyment, contact with others relationships, slef conidence
How can pain affect a patients symptoms?
Sleeping patters, poor concentration, mood, sense of self, pre-occupied.
Why is chronic pain more difficult than acute pain?
No use like a warning, no diagnosis, treatment probably won’t cure it, others dont understand
What are the two patterns of chronic pain?
Take it easy- people rest and get worried about doing things so never do it
Boom and Bust- people try too hard burn out and then have to stop then try again to catch up with what they missed
What is the problem with take it easy?
Lose muscles isolation too much time on hands and focused on pain, leading to depression and deconditioning
What are the 3 ps of pain?
Pacing, Prioritising and planning. work within limits while being productive as possible
What are the challenges of 3Ps?
Might not do as much as really want, not as good as before, other events can’t be changed
What can relaxation do for pain?
reduces muscle tension from pain, which leads to aches and discomforts. Recognises the tension, change experience of pain, helpful for dealing with stress,
How can distraction be used for pain managment?
Focusing on other things other than the pain, includes activities or thinking about something like mental imagary
What is a box of tools in pain?
Box of things to help them with the pain to help deal with pain
What things can affect mental health?
Biological, psycological social all have their own ways of addressing things
What are common mental health disorders/problems?
Depression, generalsised anxiety disorder, panic disorder, phobias, social anxiety disorder, OCD PTSD
Who has more mental health problems?
Younder people/ middle age, women as well
What is the trend with mental health problems?
More people asking for help, rates of problems, more antidepressants prescribed
Are rates going up?
Possibly but it is hard to tell as lots of factors at play
What could make things worse in terms of mental health?
worsening economic conditions, changes to services, increasing inequality isolation loss of meaning or hope
What are the symptoms of depression?
Sadness loss of interest or pleasure, feelings of guilt or low self-worth diturbed sleep appetite, tiredness and poor concentration
How common is depression and anxiety?
1in 6 have it at any time
What is the link with depression and physcial health?
It is linked to many diseases and harder for people to follow treatments
What is the link between physical health and depression?
Certain diseases can lead to depression for a variety of reasons
What are the trends in suicide rates in the UK?
Leading cause of death in men under 45, less likely to seek help
What is the blood brain barrier for?
To regulate the nutrients entering the CSF
What forms the blood brain barrier?
the capillary endothelial cells with tight junctions, the basement membrane not fenestrated, pericytes and astrocytes foot processes
What are the main arerial supplies to the brain?
Vertebral arteries, internal carotid artery.
Which arteries are supplied by the vertebral arteries?
Posterior inferior cerebellar artery, anterior inferior cerebelar artery, superior cerebellar artery, pontine branches, posterior serebral artery
What is the posterior circulation?
The area of arteries supplied by the vertebral arteries
What sipplies the basilar artery?
the vertebral arteries
Which vessels are in the anterior ciculation?
the anterior cerebral artery the middle cerebral artery
Where does the anterior cerebral artery supply?
The medial surface and margins of the central sulcus.
What does the middle cerebral artery?
The temporal lobes and lateral parts of the brain
What does the posterior ccerebral artery do?
Supplies the medial and posteria surface of the occipital cortex
What is the great cerebral vein of Galen?
Where the internal cerebral vein, straight sinus join to go into the transvers sinus and jugular vein
What is the vasculaure of the spinal cord?
Along the anterior there are the spinal cord arteries and veins on the posterior thre is a complex plexus of veins
what area is the inferior horn of the lateral ventricle in?
The temporal lobe
What area of the brain is the anterior horns of the lateral ventricle?
It is in the frontal lobes
What connects the 2nd and third ventricle?
Interventricular foramen (of monroe)
What connects the 3rd and 4th ventricle?
the cerebral aqueduct/ slylvius
What are the two exits of the fourth ventricles?
Foramen of majendie in middle foramen of Luska in the lateral
Where does the crebral aqueduct pass through?
the basal ganglia
What are ependymal cells?
They are cilliated cells that help to the flow of CSF
What is choroid plexus and where is it?
Choroid plexus is in the lateral ventricles and the 4th ventricles it is responsible for production of CSF
Where does the CSF drain?
Through the arachnoid granulations. also peripheral nerves and into sinuses directly
What are the anterior visible structures of the brainstem?
The pons mamillary bodies, bulbo pontine sulcus, olive pyramid anterior median fissure
What are the regions of the pons?
The middle, inferior and superior cerebral peduncles
What are the strucures of te posterior brainstem?
The thalamus, the superior colliculi, inferior colliculi and floor of the 4th ventricle cuneate tubercle and gracile tubercle
What do the superior colliculi do?
they are involved in visulal perception and communicate wiht the lateral genigulate nucleus
What doe the inferior colliculi do?
They deal with auditory information, medial geniculat nucleus of the brain and thalamus
What is the name for the 4th vetricle surface?
The rhomboid fossa
What are the strucutres of the superior midbrain?
Tectum- the colliculi periaqueductal grey, the cerebral aqueduct
Tegmentum- crus cerebri, redu nucleus substantia nigra
What is in the medulla cross section?
The pyramids, spinocerebellar tracts, nucleus cuneatus fasciculus cuneatus, the same for gracilis
Where is the anterior commisure?
The front of the lateral ventricle near the hypothalamus
Where is the pineal gland?
It is below the splenium of the corpus callosum
What can interrrupt the 3rd ventircle?
The interthalamic adhesion
What is involved in the papez circuit?
entorhinal cortex, the hippocampus, fimbria fornix mamillary bodies, thalamus, cingulate girus, cingulate bundle posteriorly into enteorhinal cortex
where is the thalamus?
posterior to the globus pallidus
What does the internal capsule separate?
The globus pallidus and caudate anteriorly and posteriorly the thalamus
What does the external capsule separate?
It separates the putamen and the claustrum
What does the extreme capsule separate?
The claustrum and the insula
Where is the hypothalamus?
wither side of the ventricule,
What does the hypothalamus?
Control centre for pituitary and other regulatory functions
What is the septum pellucidum?
The part that separates the two lateral ventricles
What are the divisions of the cerebellum?
Right and left lobe, have transverse fissure and primary lobes
What are the three layers of cerebellum?
Molecular(outermost) purkinje, and granule layers
What are mossy fibres?
They are inputs to the cerebellum that enter throug the middle peduncle they come from the dentate nucleus of the hippocampus
What are climbing fibres?
Inputs to the cerebellum for the inferior peduncle from the inferior olive
What are purkinje cells?
They are outpuut cells that go to the dentate nucleus
What does the superior cerebellar peduncle connect?
Midbrain diencephalon and cerebrum
What is the middle cerebellar peduncle?
It connects the cerebellum with the pons and midbrain
What does the inferior cerebellar peduncke linkd?
The nuclei in the medulla as well as ascending and descending tracts to spinal cord
What information does the inferior cerebellar peduncle carry?
Proprioceptive and vestibular information
what type of information does the middle peduncle carry?
information about voluntary movement
What are the roles of the spinal cord?
recievs afferent fibres from sensory receptors of the runk and limbs
controls movement of limbs
autonomic innervation
Where are the enlargements of the spinal cord?
Between C3-T1 for the arm and L1-S3 for legs
What is the tip of the spinal cord called?
The conus meullaris, the final part of arachoid mater is the filum terminale
Where is the end of the spinal cord?
L3 in birth, L1 or L2 in adult hood
How are the spinal nerves organised?
There 8 C 12T 5L 5S 1C c1 pairs of nerves
What is in the dorsal root ganglions?
primary afferents cell bodies in the dorsal spinal root ganglion
What is carried in the ventral roots?
Efferents cell bodies in grey matter
Which levels of the spinal cord have larger amounts of white matter?
The upper levels have more white matter compared to grey
what are the rexeds laminae?
They are layers of the grey matter 1-3 substantia gelatinosa 9 motor supply
What are the ascending tracts of the brain?
Medial leminiscal or dorsal columns, spinothalamic, spinocerebelar
What does the Medial leminiscal /dorsal column carry?
Proprioception vibration discriminative touch, gracilis for lower body and cuneatus for upper body. they ascend to the medulla and cross
What does the spinothalamic tract do?
arries pain and temperature and crude touch ascends on the same side for 1 or 2 segments then crosses up to thalamus
What doe the spinocerebellar tracts do?
proprioception going to the dorsal ipsilatral cerebellum
What does the spinoreticular pathways do?
Deep/chronic pain
What are some descending pathways?
corticospinal, tectospinal, rubrospial, vestibulospial, reticulospinal
What dos the corticospinal tract do?
It carries control of the voluntaru muscles, decussates at the medulla
What doe the tectospinal tracts do?
head turning in response to visual stimmulus
What does the rubrospinal tract do?
Assistes in motor function
What do the vestibulospinal tracts do?
they alter muscle tone and posture
What do the reticulo spinal tracts do?
Spinal reflexes
What is brown-sequard syndrome?
Hemi-section of the spinal cord. ipsilateral weakness below the lesion due to damage to ipsilateral descending motor cortico-spinal tract. Ipsilateral loss of dorsal column propreoception. contralateral loss of spinothalamic pain and temperature below lesoion
What are nerve conduction studies?
They investigate the periperal nervous system
What are electromyographies
Looking at the periperal nervous system and the motor neuron- root nerve junction and muscle itself
What does electroencephalography?
Looks at activity in the brain?
what are Evoked potentials?
electrodes on brain and arm or leg, look at stimulating the arm or leg and seeing its effect in the brain
How is sensory system tested in nerve conduction studies?
Stimulate nerve endings and measure along the course off the nerve looking at speed and amplitude
How are motor functions assessed?
They stimulate the nerve and look for the contraction of the muscle using the probes
What is the speed and and amplitude representing?
the amplitude is the number of axons the speed is myelination
What does the EMG measure?
measure motor unit function
What can you look for in electromyography?
Loss of strength, NMJ, muscle related, collateral sprouting
how can you look at myesthenia gravis?
The regularity of the speed of the junction
What are EEGs?
Look at surface electrical energy in different areas of the brain
What are lots of EEGs used for?
They are used to look at epilepsy to locate areas etc
What do frontal lobe seisures look like?
Often arise in sleep, asymmetrical flexion extension
What is a non-epileptic seizure?
often very long, occasional pelvic thrusting often close eyes, can talk and cry in attack
What is trans cranial magnetic stimulation?
stimulating the brain with magnets and measuring signals
