Nervous system stuff Flashcards
Frontal lobe - 3 areas
Precentral gyrus
prefrontal cortex
broca’s area
Precentral gyrus
(frontal lobe)
primary motor cortex for voluntary muscle activation
prefrontal cortex
(frontal lobe)
controls emotions and judgments
Broca’s area
(frontal lobe)
controls motor aspects of speech
Parietal lobe - area and function
Postcentral gyrus - primary sensory cortex for integration of sensation
-receives fibers conveying touch, proprioceptive, pain and temperature sensations from opposite side of body
Temporal lobe - 3 areas
Primary auditory cortex
Associative auditory cortex
wernicke’s area
Primary auditory cortex
(temporal lobe)
receives/processes auditory stimuli
associative auditory cortex
(temporal lobe)
processes auditory stimuli
wernicke’s area
(temporal lobe)
language comprehension
occipital lobe - 2 area
primary visual cortex
visual association cortex
primary visual cortex
occipital lobe
-receives/processes visual stimuli
visual association cortex
occipital lobe
-processes visual stimuli
insula brain function
-associated with visceral functions
limbic system
-limbic lobe, hippocampal formation, amygdaloid nucleus, hypothalamus and anterior nucleus of thalamus.
- concerned with instincts and emotions
- basic functions include feeding, aggression, emotions, and endocrine aspects of sexual response.
White matter
myelinated nerve fibers located centrally
basal ganglia (BG)
-masses of gray matter. (striatum, GPi, GPe, sub thalamic nucleus and substantial nigra)
circuits:
oculomotor (caudate loop)= functions with saccadic eye movements
motor loop (putamen loop) = reinforces selected pattern, suppresses conflicting patterns. prep for movement
limbic circuit = organize behavior (executive function, problem solving, motivation) and procedural learning
diencephalon includes
thalamus, subthalamus, hypothalamus, and epithalamus
Thalamus - sensory nuclei
(has sensory/motor/other nuclei)
sensory - integrate and relay sensory info from body, face, retina, cochlea, and taste receptors to cerebral cortex and subcortical regions ; smell is exception**
Thalamus - motor nuclei
(has sensory/motor/other nuclei)
motor - relay motor info from cerebellum and globes plaids to percentile motor cortex.
Thalamus - other nuclei
(has sensory/motor/other nuclei)
other - assist in integration of visceral and somatic func
Subthalamus
- involved in control of several functional pathways for sensory, motor, and reticular function
Hypothalamus
- integrates and controls fun of ANS and the neuroendocrine system
- maintains body homeostasis (body temp, eating, water balance, anterior pituitary function/sexual behavior, and emotion)
Epithalamus - habenular nuclei and pineal gland
habenular nuclei = integrate olfactory, visceral, and somatic afferent pathways
pineal gland = secretes hormones that influence pituitary gland and several other organs; influences circadian rhythm
Brainstem - midbrain, pons, medulla oblongata
midbrain - connects pons to cerebrum; superior peduncle connects midbrain to cerebellum
pons - connects medulla oblongata to midbrain, allowing passage of important ascending and descending tracts
- medulla oblongata - connects spinal cord with pons
Cerebellum
(“little brain”)
located behind dorsal pons and medulla in posterior fossa
- archicerebellum = equilibrium, regulation of muscle tone, helps VOR
- paleocerebellum = modifying muscle tone and synergistic actions of muscles. maintenance of posture and voluntary movement control
- neocerebellum = smooth coordination of voluntary movements; ensure accurate force, direction, and extent. Important for motor learning, sequencing of mvmt, and visually triggered movement
Autonomic nervous system - ANA
sympathetic - fight or flight, emergency response.
parasympathetic - rest and digest
A fibers (4 types)
large, myelinated, fast-conducting
alpha= proprioception, somatic motor beta = touch, pressure gamma = motor to muscle spindles delta = pain, temperature, touch
B fibers
small, myelinated, conduct less rapidly
-preganglionic autonomic
C fibers
smallest, unmyelinated, slowest conducting
dorsal root = pain, reflex responses
sympathetic = postganglionic sympathetics
Nonfluent aphasia
Expressive.
*Broca’s motor aphasia, expressive aphasia
- central language disorder in which speech is typically awkward, restricted, interrupted, and produced with effort.
- lesion involving the third frontal convolution of the left hemisphere (Broca’s area)
Verbal apraxia
Expressive.
-impairment of volitional articulatory control secondary to a cortical, dominant hemisphere lesion
Dysarthria
Expressive.
- impairment of speech production resulting from damage to the central or peripheral nervous system;
- causes weakness, paralysis or incoordination of the motor-speech system (respiration, articulation, phonation, and movements of jaw and tongue)
Fluent aphasia
Receptive.
- Wernicke’s aphasia, receptive aphasia
- spontaneous speech is preserved and flows smoothly, while auditory comprehension is impaired.
- lesion in the posterior frist temporal gyrus of the left hemisphere (Wernicke’s area)
Global aphasia
receptive and expressive.
-severe aphasia. marked impairments in comprehension and production of language.
HR, BP and exercises.
normal for HR to increase in direct proportion to intensity
SBP increases, while DBP remains the same or decreases moderately
Cheyne-Stokes respiration
period of apnea lasting 10-60 seconds followed by gradually increasing depth and frequency of respirations
-depression of frontal lobe and diencephalic dysfunction
Apneustic breathing
abnormal respiration marked by prolonged inspiration.
-damage to upper pons
Testing of sensation - order
Test superficial sensations (pain, temperature, touch)
Test proprioceptie (Deep) sensations - Joint position, kinesthesia/movement sense, and vibration sense (pallesthesia)
Lastly, test combined cortical sensation - stereognosis, tactile localization, 2 point discrimination, barognosis (weight), graphesthesia, bilateral simultaneous stimulation.
homonymous hemianopsia
loss of half of visual field in each eye.
-contralateral to the side of a cerebral hemisphere lesion
Decerebrate rigidity/posturing
- comatose patients with brainstem lesions
- all limbs; trunk/neck in rigid extension
Decorticate rigidity/posturing
-comatose patients with lesions above superior colliculus
- upper limbs in flexion
- Lower limbs in extension
*in “cort” praying not to go to jail.
opisthotonos
-prolonged severe spasm of muscles, causing head, back, and heels to arch backward; arms and hands are held rigidly flexed.
Extrapyramidal disorders, basal ganglia dysfunction
- tics
- chorea (dancing movements)
- athetosis (slow, irregular, twisting)
- tremor (resting tremors)
- myoclonus (single, quick jerk)
Cerebellar disorders cause?
intention tremor when voluntary movement is attempted
cortical disorders
epileptic seizures, tonic/clonic convulsive movements
Fibrillation vs fasciculations
Fib = fake. cannot see twitch. spontaneous independent contraction of individual muscle fibers
Fasciculation = spontaneous contractions of all or most of the fibers in a motor unit. *can see or palpate twitch (present with LMN disorders and denervation)
Stages of recovery after stroke
6 stages
stage 1 = flaccidity
stage 2 = emergence of spasticity, hyperreflexia, synergies
stage 3 = voluntary movement possible only in synergies, spasticity strong
stage 4 = decline in spasticity and synergies
stage 5 = increased voluntary control out of synergy
stage 6 = control and coordination near normal
naming SPI levels
lesion level indicates most distal uninvolved nerve root segment with normal function; muscles must have a grade of at least 3+/5 or fair+ function
Complete vs incomplete SPI
complete = no sensory or motor function below level of lesion
incomplete = preservation of sensory or motor function below level of injury; spotty sensation, some muscle function (at least 3+/5)
ASIA impairment scale.
A = complete: no motor or sensory preserved in sacral segments S4-5
B = incomplete: sensory preserved below level and includes sacral S4-5. no motor
c = incomplete: motor preserved below the level, and most key muscles have a grade of less than 3
D = incomplete: motor preserved below level. most key muscles below have a grade of 3 or more
E = normal: motor and sensory normal
Central Cord syndrome: characteristics
UMN lesion
cavitation of central cord in cervical section. Typically due to cervical hyperextension
- loss of spinothalammic tracts with bilateral loss of pain and temperature
- loss of ventral horn with bilateral loss of motor function: Primarily UE
- preservation of proprioception and discriminatory sensation
Brown-Sequard syndrome - characteristics
UMN lesion
Hemisection of spinal cord (loss one half) due to penetration wounds (gunshot/knife)
- ipsilateral loss of dorsal columns with loss of tactile discrimination, pressure, vibration, and proprioception
- ipsilateral loss of corticospinal tracts with loss of motor function and spastic paralysis below level of lesion
- contralateral loss of spinothalamic tract with loss of pain and temp below level of lesion; at lesion level, bilateral loss of pain and temp.
Anterior cord syndrome - characteristics
UMN lesion
loss of anterior cord (motor) typically flexion injuries of C-spine
- loss of lateral corticospinal tracts with bilateral loss of motor function, spastic paralysis below level of lesion
- loss of spinothalamic tracts with bilateral loss of pain and temp
- preservation of dorsal columns: proprioception, kinesthesia, and vibratory sense.
Posterior cord syndrome - characteristics
UMN lesion - extremely rare
loss of dorsal columns bilaterally (sensory)
- bilateral loss of proprioception, vibration, pressure, and epicritic sensations (stereognosis, 2 point discrimination)
- preservation of motor function, pain, and light touch
Cauda equina injury - characteristics
LMN lesion
loss of long nerve roots at or below L1
variable nerve root damage (motor and sensory signs); incomplete lesions common
- flaccid paralysis with no spinal reflex activity
- flaccid paralysis of bladder and bowel
- potential for nerve regeneration; regeneration often incomplete, slows and stops after about 1 year.
Autonomic dysreflexia
emergency situation.
- noxious stimulus precipitates a pathological autonomic reflex.
-elevate head, check and empty catheter first. Medical emergency.
Heterotopic bone formation (ectopic bone)
abnormal bone growth in soft tissue
Multiple sclerosis (MS)
a chronic, progressive, demyelinating disease of the CNS affecting mostly young adults
4 types of Multiple sclerosis
Relapsing-remitting (RRMS) - periods of recovery
Primary-progressive (PPMS) - disease progression from onset without plateaus or remissions, or with occasional plateaus and temporary minor improvements
Secondary-progressive (SPMS) - initial relapsing-remitting course, followed by progression at a variable rate. May also include occasional relapse or minor remission
Progressive-relapsing (PRMS) - progressive disease from onset but without clear, acute relapses that may or may not have some recovery or remission. Commonly seen with onset after 40 years old.
Parkinson’s disease
basal ganglia
chronic, progressive disease of the CNS with degeneration of dopaminergic substantial nigra neurons and nigrostriatal pathways.
-classic symptoms = (TRAP)
Tremor (resting), rigidity, akinesia (no or slow movements), postural reflexes (impaired)
Hoehn and Yahr classification stages of parkinson’s
I = minimal or absent disability, unilateral symptoms
II = minimal bilateral or midline involvement, no balance involvement
III = impaired balance, some restrictions in activity
IV = all symptoms present and severe; stands and walks only with assistance
V = confinement to bed or w/c
Myasthenia gravis
neuromuscular junction disorder characterized by progressive muscular weakness and fatiguability on exertion.
autoimmune attack on acetylcholine receptors on postsynaptic junction
**fatigability is characteristic. Repeated muscle use results in rapid weakness.
Myasthenic crisis
myasthenia graves with respiratory failure
= medical emergency.
Tonic-clonic seizure
Grand mal
General seizure
- dramatic loss of consciousness, with a cry, fall, and tonic-clonic convulsions of all extremities.
- often have tongue biting and arrested breathing, urinary and fecal incontinence
- lasts 2-5 mins
- patient is confused, drowsy, and amnesiac about the event
- full recovery may take several hours
- some attacks are preceded by a brief aura
Absence seizures
petit mal
general seizure
- brief, almost imperceptible lapse of consciousness followed by immediate and full return to consciousness
- posture is maintained
- no convulsive muscle contrations
- may occur up to 100x/day
simple partial seizure
partial seizure
focal, begin locally, limited to a portion of the body
- consciousness preserved
- usually an identifiable structural cause
focal motor
partial seizure
-clonic activity involving a specific area of the body
focal motor with march (Jacksonian)
partial seizure
-orderly spread or march of clonic movements from initial muscles to involve adjacent muscles, with spread to the entire side
temporal lobe seizure
partial seizure
- characterized by episodic changes in behavior, with complex hallucinations
- automatisms (lip smacking, chewing, pulling on clothing…)
- altered cognitive and emotional function (sexual arousal, depression, violent behaviors)
- preceded by an aura
Complex partial seizure
simple partial seizure (focal, begin locally, limited to a portion of the body) followed by impairment of consciousness.
Cerebellar disorders - characteristics
tend to produce ipsilateral signs and symptoms
-balance and coordination issues. Intention tremors
Vestibular neuronitis, labyrinthitis
unilateral vestibular disorders (UVD)
acute infection with prolonged attack of symptoms, persisting for several days or several weeks.
caused by viral or bacterial infection
Meniere’s disease
recurrent and usually progressive vestibular disease
- episodic attacks may last mins to several hours
- usually associated with tinnitus, deafness, sensation of pressure/fullness within ear
etiology unknown, edema of membranous labyrinth is a consistent finding
