neuro- intro Flashcards
white matter is what? grey matter is what?
neuronal cell bodies
PNS- ganglia
CNS- nuclei (except basal ganglia)
4 regions of the brain
cerebrum
diencephalon
cerebellum
brain stem
what does the cerebrum include? 7 parts
*2 hemispheres- 2 parts to each lobe frontal lobe occipital lobe parietal lobe temporal lobe basal ganglia limbic system ventricles
frontal lobe is responsible for….
reasoning, planning, parts of speech, movement, emotions, problem solving
parietal lobe is responsible for….
movement, orientation, recognition, perception of stimuli
occipital lobe is responsible for….
visual processing
temporal lobe is responsible for….
auditory recognition and perception
memory, and speech
the diencephalon includes what 2 parts of the brain? what does each part do?
thalamus - takes in all sensory and sends it where it needs to be processed
hypothalamus - homeostasis
what does the cerebellum do? what three types of information does it receive and from where does it receive it?
the coordinator of movement, planning, execution of movement, posture, and head and eye movements,
- Sensory information from spinal cord
- Motor information from the cerebral cortex
- Balance information from the inner ear
what does the brainstem include? what are its 3 parts ?
10/12 cranial nerves, LOTS of nuclei and relay centers, control of autonomic action, reticular activating system
Midbrain
Pons
Medulla
where doe the spinal cord start and end?
Starts at medulla and ends at the 2 or 3rd lumbar vertebra
how many cranial nerves? how many peripheral nerves?
cranial- 12
peripheral- 31 pairs
CN 1 and 2 come from where?
fiber tracts from the brain
CN 3 and 7 come from where?
arise from brain stem
what are the 3 functions of cranial nerves?
general motor
sensory
special sensory
what are the 2 types of peripheral nerves? how are they formed?
Spinal nerve- motor and sensory roots merge to form spinal nerve
Peripheral nerve- spinal nerves merge together to form plexuses to form peripheral nerves
what are the 4 motor pathways?
Corticospinal tract (pyrimidal)
Basal ganglia system
Cerebellar system
Extrapyramidal pathways
upper motor neurons : where are their cell bodies located and where do they synapse?
have cell body in the gray matter of the brain
Axons synapse with cell body in brain stem (for CN) and in spinal cord (for peripheral nerves)
lower motor neurons: where are their cell bodies located and where do they synapse?
Cell body in the spinal cord (peripheral) called anterior horn cells
Anterior horn cell body has axon that travels through anterior root»_space; spinal nerve»_space; peripheral nerve» neuromuscular junction
Called the “final common pathway”
where do all motor pathways converge to control muscle activity?
the anterior horn
-lots of activity here
UMN damage vs LMN damage?
UMN – weakness or paralysis; poor skilled movement; increased muscle tone, hyperreflexive DTRs
LMN – ipsilateral weakness or paralysis, decreased muscle tone, hyporeflexive or absent DTRs
corticospinal tract (pyrimidal) is responsible for?
Voluntary movement
“Integrate skilled, complicated, or delicate movements by stimulating selected muscular actions and inhibiting others.”
where doe the corticospinal tract originate?
Origination – brain motor cortex
where does corticospinal tract go? (pathway)
Path – form pyramid-like structure in lower medulla where most fibers cross to contralateral medulla
Synapse with anterior horn cells or intermediate neurons
what is the corticobulbar part of the corticospinal path?
Corticobulbar – tracts that synapse in brainstem with CN motor nuclei
what does the basal ganglia do?
Maintenance of muscle tone
Body movement control – especially gross movement
i.e. walking
what is the basal ganglia complex (aka what pathway and parts of the brain is it associated with ?
Complex – “motor pathways between cerebral cortex, basal ganglia, brainstem, and spinal cord”
what does damage to the BG cause?
Damage = muscle tone changes (usually increases tone), may have abnormal posture or bradykinesia
what do the sensory pathways of the Corticospinal tract contribute to? (5 parts)
Reflex Activity Conscious sensation Body position calibration Regulation of autonomic functions BP, pulse, resp
what is the spinothalamic tract?
Pain and temperature or crude touch from nerve endings in skin within 1-2 spinal segments from cord entry
- Pass to posterior horn and synapse with secondary sensory neurons
- Cross to contralateral side and travel upward to thalamus
- Consists of smaller unmyelinated or thinly myelinated axons
what are the posterior columns of the sensory pathways? what passes through them and where do these go after?
Position/proprioception and vibration, kinesthesia, pressure, and fine touch
These sensations pass to posterior columns of cord and pass upward to medulla
Fibers synapse with secondary sensory neurons in the medulla then cross to opposite side and cont to thalamus
what is the site of the general quality of sensation?
thalamus
what does a lesion in the sensory cortex cause?
impaired fine discrimination but intact pain, touch, and position sense
what does a lesion in the posterior columns cause?
position and vibration loss
what does a lesion of the spinal cord transection cause?
loss of all sensation below transection, paralysis, exaggerated reflexes
what will still be intact even with partial cord damage?
crude and light touch intact (impulses on one side travel both sides of cord)
what are the dermatomes
Bands of skin
Innervation of sensory root of single spinal nerve
Can localize to specific spinal segment
definition of a reflex?
deep tenton reflex (DTR) : “involuntary stereotypical response that may involve as few as two neurons, one afferent (sensory) and one efferent (motor), across a single synapse”
____ reflexes are monosynaptic
DTRs in arms and legs
brisk tap on tendon of partially stretched muscle
good reflex test means what?
all are Intact – sensory nerve fibers, spinal cord synapse, motor nerve fibers, neuromuscular junction, and muscle fibers
what are the DTR segmental levels?
Ankle – S1 primarily Knee – L2, 3, 4 Supinator (brachioradialis) – C5, 6 Biceps – C5, 6 Triceps – C6, 7
what are the sections of the cutaneous stimulation ?
Abdomen Upper – T8, 9, 10 Lower – T10, 11, 12 Plantar L5, S1 Anal S2, 3, 4
5 parts of neuro exam
Mental Status Cranial Nerves Motor System Sensory System Reflexes
6 parts of mental status to evaluate?
- appearance and behavior
- speech/language
- mood (not being tested on)
- thoughts/perceptions (not being tested on)
- cognition/function
- higher cognitive function
what 5 parts of speech and language do we evaluate?
- quantity : talkative or silent?
- rate : fast or slow talking?
- volume (loudness)
- articulation of words
- fluency of speech (involves rate, flow , melody of speech)
4 fluency abnormalities
- Hesitancies in speech (as seen in patients with aphasia from strokes)
- Monotone inflections (schizophrenia or severe depression)
- Circumlocutions: words or phrases are substituted for the word a person cannot remember; e.g., “the thing you block out your writing with” for an eraser
- Paraphasias: words are malformed (“I write with a den”), wrong (“I write with a branch”), or invented (“I write with a dar”)
aphasia is usually caused by _____
dominant hemisphere problem
what is cognition testing?
Assess orientation to person, place, and time
assess attention, remote memory (further history), recent memory, new learning ability (tell 4 words and ask them to repeat in 5 min)
3 parts to assess attention
Digital span: give the patient a string of numbers to recite back to you
Serial 7s: ask the patient to subtract serial “7s” from 100
Spelling backward: ask the patient to spell W-O-R-L-D backwards
three parts to check higher cognitive function? how do you check?
Calculating ability: difficult calculations such as making change
Abstract thinking:
-Interpreting proverbs: “A stitch in time saves nine”
-Similarity exercises: What do a ball and an orange have in common?
Constructional abilty: drawing complex shape or clock
5 parts of neuro screening
- Mental Status: Level of Alertness, Appropriateness of Response, Orientation
- Cranial Nerves: Visual acuity, Pupillary light reflex, Eye movement, Hearing, Facial strength
- Motor System: Strength, Gait, Coordination
- Sensory System: Toes – light touch or pain/temperature or proprioception
5: Reflexes: DTR – biceps, patellar, Achilles
Plantar response
CN1
– Olfactory Test nasal patency Close eyes Occlude one nostril Test smell Ask patient if can smell and what smell is Test bilaterally
CN2
Optic Visual acuity Inspect optic fundi Visual fields by confrontation May need to isolate eyes for this test if patient is suspected to have a deficit
CN3
Oculomotor
Test with CN II: Inspect size and shape of pupils – compare bilaterally
Pupillary reaction to light
Near response: Pupillary constriction, Convergence,
Accommodation
what is aniscoria?
pupil size: >0.4mm difference in diameter comparatively seen in up to 38% of people
CN 3, 4 and 6: what are these called, how do you test them?
Oculomotor, Trochlear, and Abducens
- EOM in 6 cardinal directions of gaze: Determine if monocular or binocular
- Cover-uncover test
- Convergence
- ID Nystagmus: Increase or decrease when fixed on far object?
- ID Ptosis
what causes diplopia?
disconjugate extraocular eye movement
what is CN5 and what are it’s 3 components?
trigeminal nerve: 3 parts
Ophthalmic, Maxillary, Mandibular
(motor and sensory parts )
testing CN5 motor
Patient clenches teeth while palpating temporal then masseter muscles noting strength
Move jaw side-to-side
testing CN 5 sensory
Pain sensation at forehead, cheeks, and jaw bilaterally
Sharp object with blunt end (safety pin)
“Do you feel anything? Where? Does it feel sharp or dull?”
Abnormal? - Temperature sensation
Light touch – wisp of cotton
“Tell me when you feel something touch your skin.”
corneal reflex tests what 2 CNs?
sensory CN V and motor CN VII
“Look up and away from me with your eyes.”
Touch CORNEA with cotton, avoiding eyelashes.
Normal Response = Blink
Contact Lenses – diminish or delete reflex
CN 7
Inspect at rest and during conversation: Asymmetry? Tics? Abnormal Movements?
Observe in Response to Requests (raising eyebrows, frowning, etc)
CN 8
Acoustic Whispered voice test Conductive vs Sensorineural --Rinne – air vs. bone conduction --Weber – lateralization Vestibular function – rarely need to test in usual Neuro Exam
sensory info from the vestibular system is used to…?
Provides a stable visual image for the retina while the head moves
Make adjustments in posture necessary to maintain balance
3 semicircular canals test what? 2 otolith organs test what?
angular acceleration ; linear acceleration
how do the otolith organs detect linear acceleration ?
When the head is moved linearly the otolith mass slides along the hair cells either depolarizing (stimulating) or hyperpolarizing (inhibiting) them detecting a change in position.
afferent nerves from vestibular hair cells terminate in one of ____ vestibular nuclei in the ____. these 4 are…
Afferent nerves from vestibular hair cells terminate in one of four vestibular nuclei in the medulla; Superior, Medial, Lateral, Inferior
vestibular ocular reflex (VOR)- what does this allow you to do?
allows you to focus on a point when your head is moving (small movements of the eyes)
test as a reflex to make sure peoples’ brainstems are functioning
“the brain looks at the lesion” - what does this mean?
“the brain looks at the lesion” - if you have some sort of degenerative lesion (something decreasing the output) on left side of head (stroke, tumor)- then you get right of the left side function- eyes will only be able to look “towards” the lesion- cause you have knocked out the side pushing the opposite way
what is a normal reflex that you can get from stimulating the semiC canals?
Nystagmus is a normal reflex. You get it from stimulating the semicircular canals. (dix hallpike test to mimic irritating the semicircular canals- test for pathologic nystagmus)
CN 9 and 10
Glossopharyngeal and Vagus
-Voice
Hoarse? (Vocal Cord Paralysis) Nasal quality? (Paralysis of the Palate)
-Difficulty swallowing: Pharyngeal or palatal weakness
-Normal symmetrical rise of the soft palate (X) – “Say ah”
-Gag Reflex – elevation of the tongue and soft palate and constriction of the pharyngeal muscles
dolls eyes maneuver
vestibular pathway maintains ability to focus central vision even with head moving- roll head back and forth- eyes should look to the opposite side of where you roll it
CN 11
Spinal Accessory
Atrophy or fasciculation in trapezius?
“Shrug both shoulders upward against my hands.”
Strength? Contraction?
“Turn your head to each side against my hand.”
sternocleidomastoid contraction
CN 12
Hypoglossal
Listen to articulation
(CN V, VII, X, XII)
Inspect for atrophy or fasciculation
Tongue protrusion: Asymmetry? Atrophy? Deviation?
“Move your tongue side to side.”: Symmetrical motion?
Not sure?: Ask patient to push tongue against cheek while you palpate externally to assess strength
