MT2 Flashcards
Cranial nerve assessment:
1. Glossopharyngeal nerve
2. Vagus nerve
3. Accessory nerve
4. Hypoglossal nerve
- Provides sensation to the posterior third of the palate, perform gag reflex test by touching palate
- Motor supply to pharynx for swallowing, test by asking patient to speak
- Motor supply to the SCM and traps, test by turning head against resistance and shrug shoulders against resistance
- Motor supply to the tongue, stick tongue out, deviations suggest weakness
Ms. Smith case study
1. Overview
2. Past medical history
3. Cerebral angiogram
4. Lumbar puncture and CSF analysis
5. Treating headache, depression, and obesity
6. Diagnosis
- Middle aged woman with history of chronic headaches and acute consent of double vision and right eyelid droopiness
- History of depression, no hypertension or depression
- Insert catheter with dye into femoral artery, dye will move into BV of head making them visible, test patient for aneurysm (weak spot on BV that bulges out and fills with blood, can rupture and cause serious internal bleeding
- Spinal tap, assess opening pressure (pressure CSF revoked with) and CSF protein conc; opening pressure elevated in bacterial inflection, normal in viral, variable in fungal and tubercular; certain protein conc can indicate certain disorders
- Given naproxen which is anti inflammatory, if ineffective then use narcotic analgesia; if cerebral angiogram and lumbar puncture negative then can undergo dihydroergotamine treatment to narrow BV in head and block release of substances that cause headaches, continue Zoloft (SSRI) for depression; referral to dietitican for obesity
- 3rd nerve plasy, 3rd nerve control movement of eye and eye muscle, constriction of pupil, and focus of eye; complete palsy causes closed eyelid and deviation of eye; partial affects any function
Neuroanatomy overview
1. Allen Institute for Brain Science
2. Cerebral security
3. Ventricles
4. Blood brain barrier
5. circulation of the brain
- map the brain, make research and knowledge equitable by using open science practices
- 4 different forms of protection mechanisms from injury and infection for the CNS; skull and vertebrae enclose CNS; meninges are membranes below the bone that enclose the brain and sp cd, dura mater is tough double layer enclosing brain, arachnoid mater is the thin web following contours of brain, pia mater is tough tissue on surface of brain
- between pia mater and arachnoid mater is the subarachnoid space, blood from capillaries enter subarachnoid space, filter through choroid plexus in lat ventricle underlying cortex to become CSF to third ventricle, cerebral aqueduct connect to fourth ventricle, draining into circulation; CSF cushions CNS from shock and change in pressure
- BV in CNS have tightly packed layer of astroglial cells forming BBB which selectively allows certain molecules through (small) into brain
- blood supplied by internal carotid arteries running on anterior side of C spine and vertebral arteries along C spine; four merging into circle of Willis at base of brain which allows for different paths for blood to travel in event of stroke; cerebral arteries branch into smaller arteries supplying brainstem and cerebellum and split into ant (middle and dorsal), middle (lateral surface), and post (ventral and posterior surface) cerebral arteries supplying forebrain
Sp cd
1. Sp cd and nerves
2. Dermatomes
3. SCI level
4. SCI types
5. SCI stats
- sp cd is extension of brainstem, relays info from PNS to brain and facilitate reflexes; 31 spinal nerves C1-8, T1-12, L1-5, S1-5, coccygeal nerve
- area of skin innervated by a single nerve; if rash or pain in whole dermatome then indicated problem with specific nerve
- affects all parts of spinal cord below level of injury; sacral affect bowel and bladder control, sexual function, lumbar impairs movement in lower extremity, thoracic causes difficulties breathing and digestion, cervical impairs function from neck down such as swallowing, speech, movement of upper extremity
- complete or incomplete, complete is dmg across whole width resulting in complete loss of sensation and motor control, incomple is injury across part of sp cd thus retain some motor and sensory function
- many people living with SCI in Canada, expected number cases per year increasing, occurring most commonly in males between ages 20-29 and increase due to falls as pop ages
herinated disc
1. Overview
2. Risk factors
3. Treatment
- result of tear in outer layer (annulus fibrosis) of disc, disks absorb shock; most common in lumbar and cervical region
- common occurrence in all ages, risk factors are high weight, occupation, and genetics
- surgery to remove protruding portion, medicate with OTC pain meds, narcotics, anticonvulsants, muscle relaxers, and cortisone injections
Glial cells and neurons
1. Neurons and glial cells
2. Types of glial cells
3. differentiation of nerve cells
4. types of neurons
- 100 bil neurons, thought to be many glial cells but new tech show less than 1:1 ratio of glial to neurons
- ependymal cells line ventricles and produce CSF by filtering blood, astrocyte nourish and structurally support neurons, microglial derived from mesoderm def, oligodendroglial cells forms myelin in CNS, Schwann cell forms myelin in PNS
- glial and neurons begin as undifferentiated self-renewing multipotent neural stem cells, convert into progenitor cells which act as precursor cells, converting into nondiving primitive neuroblasts or glialblasts; neuroblasts specialized into interneurons or projecting neurons; glialblasts differentiate into oligodendroglia or astrocytes
- sensory neurons with direct dendrite axon connection such as bipolar neurons of the retina or somatosensory neurons sent afferent info to CNS; interneurons with large web of dendrites such as stellate cells of thalamus, pyramidal cells of cortex, and purkinje cells of cerebellum receive info from sensory neurons and formulate response to send to motor neurons; motor neurons wth complex branches and long axons send efferent signals to muscles
evolution of CNS
1. vertebrate brain
2. mammal brain
3. human brain
- three part brain consisting prosencephalon responsible for olfactionn, mesencephalon for vis and aud, and rhombencephalon for movment and balance
- anterior prosencephalon dev into cerebral hemispheres calledd telencephalon, posterior prosencephalon called diencephalon includes thalamus, rhobencephalon div into metencephalon (cerebellum) and myelencephlaon (lower region of brainstem)
- three parts, forebrain for cog progessing, brainstem for reg func, and sp cd for reflexive motor func
Brain stem: hindbrain
1. cerebellum
2. medulla oblongata
3. reticular formation
4. pons
- coordinates movement, motor learning, posture, balance and plays role in cog such as language processing, working memory, and social cog
- regulate essential functions such as breathing, HR, coughing, sneezing, etc; dmg is fatal
- network reg circadian rhyth, general arousal, and relay info between brain and sp cd, stim area in anesthetized cats produce waking pattern of electrical activity
- control essential functions and relay info between brain and sp cd
Brain stem: midbrain
1. tectum
2. tegmentum
- lower sensory part consisting of superior colliculus recieving vis input and inferior colliculus recieving aud input
- upper motor part consisting of red nucleus for limb movement, substantial nigra connecting to forebrain for reward and avoidance behaviour, PAG surrounding cerebral aqueduct for species-specific behaviour and mod pain response
brainstem: diencephalon
1. thalamus
2. epithalamus
3. hypothalmus
- largest structure in diencephalon acts as relay centre for sensation, sends sensory input to appropriate part of brain for processing, contains 20 nuclei; lateral geniculate body receive vis projection, medial geniculate body receive aud projection, ventrolateral posterior nuclei for touch, pain, pressure, and temp (somatosensory)
- small, contains pineal gland which secretes melatonin to produce sleepiness to reg circadian rhythm and habenula reg hunger and thirst
- regulate motivational behaviours such as hunger, thirst, body temp, sex drive, etc. and interacts with pituitary gland to control endocrine func
neurological assessment
1. olfactory nerve
2. optic nerve
3. fundus
4. photoreceptor
- nerve I, responsible for sense of smell, test using something familiar with strong scent (coffee, orange peel)
- nerve II, responsible for vision, test visual acuity using Snellen charts, colour vision tested with Ishihara plates, visual fields (peripheral vis) tested by having patient look straight ahead while moving fingers in each quadrant, visual inattention can be tested by moving both fingers at same time, visual field decrease with age; test pupil reflex by blocking light from one eye and shining light into other, if functioning well then both pupils with constrict
- the interior surface of the eye including retina, optic disc, macula, and fovea, and posterior pole (space between optic disk and macula), optic disk is blind spot where optic nerve attaches to retina
- convert photons into AP interpreted as vis info, macula is highly specialized with many photoreceptor for fine detail, fovea is high conc of photoreceptor for highest visual acuity
neurological assessement
1. oculomotor nerve, trochelar nerve, and abducens nerve
2. trigeminal nerve
3. facial nerve
4. vestibulocochlear nerve
- II, IV, and VI involved in movements of the eye, test by having patient look straight ahead and follow your fingers with eyes only as you move fingers in all directions
- V involved in sensory supply to face and movement of muscles of mastication, three branches ophthalmic, maxillary, and mandibular, test sensory by using light touch such as feather to touch each part of three parts of face, test motor supply by asking patient to clench teeth, observe and feel the contraction of masseter and temporalis muscles
- VII, responsible for movement of facial muscles, patient makes faces to test motor supply, crease forehead, close eyes against resistance, puff out cheeks, bare teeth
- VIII responsible for hearing, Rinne test place tuning fork on mastoid process and compare to tuning fork next to ear, next to ear should be louder
forebrain
1. limbic sys
2. basal ganglia
3. neocortex
- subcortical, self regulatory processes such as emotional processing, hippocampus responsible for memory and learning, visceral and endocrine function, and emotional behaviour; amygdala for emotional learning, fear, and reward; corpus callosum connects hemispheres; cingulate gyrus spanning neocortex above cc connects various brain regions and involved in sexual behaviour; mamillary body; and fornix
- subcortical circuit, involved in controlling and coordinating movement and habit (stimulus-response) formation to reduce effort
- four lobes of the brain, six layers of cells, heavily wrinkled to hold greater SA for information, hemisphere separated by longitudinal fissure, frontal lobe separated from parietal lobes by central sulcus and from temporal lobe by lateral sulcus, parietal lobs separated from the temporal lobes by lat fissure, no def boundaries for the occipital lobe
- Huntington’s disease
- Parkinson’s disease
- autosomal dominant disease due to abnormal expression of IT-155 gene on chromosome 4 encoding for protein huntingtin, avg age 30-54, progressive death of basal ganglia cells characterized by motor, cog, and psychiatric symptoms such as impairment of involuntary (chorea) and vol movements, loss of thinking speed and flexibility and other cog skills, and depression (most common), mania, OCD, anxiety, etc
- avg age 62, projection from substantial nigra to basal ganglia dies, tremours in limbs, rigid movements and difficulty balancing; treated using carbidopa-levodopa which is converted to dopamine in the brain, allowing it to bypass BBB, with progression of disease, benefit of levodopa is less stable
cortical org
1. primary, secondary, and tertiary areas
2. cellular org
3. cortical connections
4. crossed brain
- primary recieve projections from major sensory sys or send motor projections to muscle; secondary adj and interconnected with primary forms sensory related functions such as form, music, motion for vision and send motor input to primary; tertiary receive sensory info from secondary and mediate complex activities such as language and attention and sent to frontal tert area to formulate plan of action
- 6 layers with diff cells and functions related to input and output; layers V and VI pyramidal neurons send axons to other brain areas and to spinal cord, prominent in motor cortex; IV comp stellate neurons in primary areas of sensation receive input from sensory and cortical areas; layers I, II, II receive input from layer IV, well dev in secondary and tertiary regions to perform integrative func
- four type of axon projection connection neocortex regions; long connections between one lobe and another, short connections within lobe, interhemispheric commissures, connections through thalamus
- hemisphere responds to sensory stimulation from the contralateral side sent through decussations connecting sensory and motor info across midline
Electrical recording
1. Single cell recording
2. Electroencephalogram (EEG)
3. Event related potentials (ERP)
4. Magnetoencephalography (MEG)
- high res, measure voltage change (AP) in single cells
- cheap, Use electrodes on surface of the skull to measure the electrical activity of summed activity of different states of consciousness; awake beta, awake but relaxed alpha, slow freq high amp waves interrupted by great AP for drowsiness, slow high amp delta sleep waves
- cheap, change in the electrical signal in response to sensory stimulus, repeated present stimulus and avg result to find location and time of processing to show readiness potentials processing info before motor response; P component peak with processing, N component dip with detecting and distinguishing stimuli
- Expensive, Uses magnets to detect electrical fields of neurons to create map of magnetic intensity
Brain stimulation
1. Intracranial brain stimulation
2. Transcranial magnetic stimulation
- surgically place thin electrode into target areas deep in brain, Implant neurostimulator into chest, program it to gen personalized electrical impulses to target brain regions to regulate abnormal neural activity and limit side effects of movement disorders; alleviate tremors, rigidity, and involuntary movements
- pass current through the coil which creates magnetic field around coil, stimulate neurons to depolarize; can cause nausea
Structural imaging
1. Conventional radiography
2. Pneumoencephalography
3. Angiography
4. Computed tomography
- quick andcheap X rays well absorbed by bones, then soft tissues, and least by water; easy to id fractures and gross brain abnormalities
- Remove small amount of CSF and replace with air, use X rays to track air as it moves through ventricles to image brain, not often used since it can be painful
- substance absorbing X rays is injected into blood, as blood moves into brain, X rays produce image of BV
- use X rays and computer processing to generate detailed cross sectional images of body
dynamic/functional imaging
1. PET
2. MRI
3. fMRI
4. magnetic resonance spectroscopy
5. diffusion tensor imaging
6. optical tomography
- radioactive substance injected into blood decays and releases positrons to stabilize, positrons annihilate when in contact with free e-, releasing photons detected by machine, increase blood flow with increase in neural activity; compare control and stimulation scenarios by substracting difference, mostly used in research not clinical
- time-consuming, high quality, normally hydrogen field unaligned use strong magnetic field to align hydrogen nuclei poles in body and apply second magnetic field in a different direction, removed 2nd field and measure relaxation rate time taken to realign with original field; relaxation rate varies with tissue producing different intensities on image to differentiate between tissues
- increase in neuron activity increase BF and oxyhemoglobin, fMRI detect difference in ratio of oxyhgb and deoxyhgb using MRI to locate areas of brain activity
- breakdown of metabolities distinguishes nerves cells from other substances
- cheap and portable, images nerve fibers by detecting direction water molecules move
- fNIRS, difference between amount infrared light reflected by oxygenated and deoxy blood, measure brain’s BF and avg O2 consumption
epliepsy
1. EEG
2. provoked seizure
3. first seizure
4. idiopathic generalized epilepsy
- detect abnormal brain activity; partial seizure is when abnormal discharge restricted to few brain regions, brief loss of consciousness, sensation or emotions; generalized seizures is widespread throughout brain, convulsions, loss of muscle tone,and loss of consciousness; shows as large distinctive spikes on EEG or loss of signal and able to id region of seizure
- specific triggered or underlying conditions such as drugs or sleep deprivation; structural abnormalities in the brain can also provoke seizure in individuals without pre-existing epilepsy diagnosis
- usually between age 16-25, comprehensive evaluation to determine underlying cause and monitoring for future seizures
- seizures occur without identifiable cause, commonly absence seizure where there are brief lapses in awareness
V1
1. overview
2. structure
3. lesion
- first area of processing, recieve visual input from LGN and send to extrastriate cortex areas for higher processing
- striate cortex, laminar org most distinct in layer 4, has more than one distinct function (heterogenous); comp blobs are metabolically more active and stain deeper thus sensitive to color , pass info to V4 while interblobs are sensitive to orientation pass info to MT/V5 for motion
- do not have conscious perception of vision but have unconscious perception for vision during locomotion due to LGN connections to V2 and from sup colliculus to thalamus
vision
1. occipital lobe
2. visual field and visual pathway
3. other vision structures
4. cortical structure
- main lobe responsible for processing visual information, ability to precieve and interpret visual stimuli; contains primary visual cortex (v1) for basic visual info and other areas for complex visual processing such as visual processing and spatital awareness
- images in the left visual field are projected onto the right side of the retina and sent electric signal down the optic nerve converging at optic chiasm to right optic tract, right lateral geniculate nucleus in thalamus down optic radiation to v1
- vision related areas in brain make up 55% total cortex, vision is dom sense, calcarine sulculus of V1 div upper and lower visual field, lingual gyrus of temporal lobe contain V2 and ventral posterior area, fusiform gyrus of temporal lobe contain V4
- human cortex has six layers but V1 has more than six
V2
1. overview
2. structure
3. dorsal stream
3. ventral stream
4. STS stream
- sent output to parietal lobe for dorsal stream, output to inferior temporal ventral stream, and output to superior temporal sulcus STS stream
- thin stripes for color perception, thick stripes for form and motion perception
- visual guidance of motion
- object perception
- connected to many other parts of temporal lobe such as Wernicke’s area; visuospatial function (faces, biological motion), language processing ( language and voices), and social cog (theory ofmind) and perception
- V3
- V4
- V5
- receive info from V1 and V2 for dynamic form
- info from the V2, responsible for colour, colour vision allow primates to have higher visual recognition due to its role in detection of movement, depth, and position
- info from V1, vision and motion