Quiz 1 Flashcards
how does loss of myelination affect the propagation of action potentials in axons?
it slows down propagation of action potentials
what are the 2 disorders of CNS demylenation?
MS and neuromyelitis optica
what 2 things can happen to axons that lead to pain?
ectopic foci or ephaptic transmission
what is ectopic foci?
a demyelinated axon region generates an AP in an abnormal place
increase in ion channels
what is ephaptic transmission?
crosstalk b/w areas of demyelination on adjacent axons
in ephaptic transmission, instead of transmitted APs through synapses, they …
jump from one neuron to another through cross talk in areas of demylenation
what is multiple sclerosis (MS)?
an autoimmune neurodegenerative disease of the CNS that destroys the myelin sheath and attacks oligodendrocytes causing plaques to form
is MS an CNS or PNS disease?
CNS
what glial cells are attacked in MS?
oligodendrocytes
what is reactive gliosis?
proliferation of glial cells in injured area of CNS leading to scar formation (plaques) in MS
what is the most common chronic inflammatory condition of the CNS?
MS
who is more likely to be affected by MS, males or females?
females
when is MS usually diagnosed?
between the ages of 20-40
what environmental factors may increase risk for MS?
inadequate sunlight exposure and low vit D levels
what are common s/s in MS?
visual disturbances (hallmark sign and often the first sign)
positive Lhermitte’s sign (electric shock-like sensation when flexing the neck forward)
sensory disturbance (numbness, tingling, pain)
motor dysfunction (weakness, imbalance, incoordination, reflex changes)
cognitive and memory deficits
heat sensitivity
why should a PT be cautious of overexertion with a patient who has MS?
heat often worsens symptoms or make new ones appear
what are the 4 types of MS?
relapsing-remitting MS
primary progressive MS
secondary progressive MS
progressive relapsing MS
what is relapsing-remitting MS?
alternating pattern of relapsing and remitting
how long does an MS relapse generally occur?
varying b/w 24 hours to months
how long does an MS remission generally occur?
a month or longer
what is the most common initial course of MS?
relapsing-remitting MS
what does relapsing-remitting MS usually progress to?
secondary progressive MS
what is primary progressive MS?
a steady decline in function with no clearly defined relapse periods but rather day-to-day fluctuations
about what % of MS cases are primary progressive MS?
10%
what is secondary progressive MS?
a combination of relaping-remitting and primary progressive MS that starts as relapsing-remitting and turns into primary progressive
what is progressive relapsing MS?
similar to primary progressive MS where the is a steady decline but this type has relapses of exacerbated symptoms
about what % of MS cases are progressive relapsing?
5%
how is MS diagnosed?
with an MRI that shows the plaques in the SC and brain
with a cerebrospinal fluid (CSF) analysis (spinal tap) to detect antibodies associated with MS
neurological exam (PT’s role!)
what is clinically isolated syndrome (CIS)?
a 1st episode of neurologic symptoms that last more than 24 hours and resolve completely with no apparent cause that may be a 1st sign of MS
can be monofocal (a single s/s) or multifocal (many s/s)
what syndrome may be the 1st sign of MS?
clinically isolated syndrome
what is neuromyelitis optica?
a very rare, severe autoimmune disorder where immune cells primarily attack the optic nerve and SC
what are the s/s of neuromyelitis optica?
optic nerve damage (swelling, inflammation, leading to pain and loss of vision)
motor and sensory disturbances in the arms/ legs
bowel and bladder dysfunction
what disease is often misdiagnosed as MS but is much more severe?
neuromyelitis optica
what 2 diseases involve demyelination in the PNS?
peripheral neuropathy and Guillain-Barre syndrome
what is peripheral neuropathy?
disease that affects large diameter axons 1st (light touch, conscious proprioception)
an umbrella term for any pathological changes involving peripheral nerves
what are some common causes of peripheral neuropathy?
metabolic abnormalities like diabetes
autoimmune disorders
viruses
trauma
toxic chemicals
what is Guillain-Barre syndrome (GBS)
an autoimmune disease triggered by bacterial/viral infection in most cases causing acute PNS inflammation and demyelination attacking the Scwann cells
what is the most common GBS in North America and Europe?
acute inflammatory demyelinating polyneurpathy (AIDP)
what glial cells are attacked in GBS?
Schwann cells
can there be regrowth of axons in GBS?
yes, bc it occurs in the PNS!
does GBS occur more in males or females?
males
what are the s/s of GBS?
decreased sensation
limb weakness/skeletal muscle paralysis
pain
respiratory muscles weakness
symptoms are bilateral and move from distal to proximal
what CN involvement is there in GBS?
facial palsy and CN 7 and 5
what is the disease progression of GBS?
rapid onset with the worst s/s w/in the 2-4 weeks followed by recovery
how is GBS diagnosed?
CSF analysis looking for elevated protein w/very few immune cells (WBCs)
electromyography and/or nerve conduction study
neurological exams
what are the 2 synaptic dysfunction diseases?
myasthenia gravis and channelopathy
what is myasthenia gravis?
an autoimmune disease causing severe muscles weakness (motor symptoms) from antibodies against ACh receptors so ACh can’t bind causing weak/no muscles contractions
what receptors are affected in myasthenia gravis?
ACh receptors
t/f: there is thymus gland involvement in myasthenia gravis
true bc the thymus makes WBC and T-cells and may contribute to antibody production
are males of females usually diagnosed with myasthenia gravis earlier?
females
t/f: there is a genetic predisposition to myasthenia gravis
true
what are the s/s of myasthenia gravis?
increased weakness and fatigue w/repetative use for skeletal muscles
fluctuating weakness that improves after a period of rest
progressive symptoms
what muscles are commonly affected 1st in myasthenia gravis?
extraocular muscles, causing ptosis (droppy upper eyelid) and diplopia (double vision)
how is myasthenia gravis diagnosed?
tensilon test (administration of a drug (tensilon) that blocks the AChE to activate the muscles) which does nothing for ptosis is not myasthenia gravis
electromyography
blood test for the presence of AChR antibodies
what is channelopathy?
an genetic or acquired autoimmune disease causing dysfunction of ion channels that leads to disease in the nervous, cardiovascular, respiratory, endocrine, urinary, and/or immune systems
what are 2 examples of a channelopathy?
Lambert-Eaton syndrome and Brugada syndrome
what is Lambert-Eaton syndrome?
channelopathy that disrupts voltage gated calcium channels in the axon terminal of the motor neurons causing generalized progressive muscle weakness
what is Brugada syndrome?
an inherited channelopathy that affects voltage-gated sodium channels in cardiac muscle causing abnormalities of cardiac rhythm
how does spina bifida occur?
the inferior neuropore doesn’t close
what is the least severe form of spina bifida?
spina bifida oculata
what may be the only s/s of spina bifida oculata?
hair at the end of the back
what is spina bifida aperta/cystica?
spinal defect clearly visible from the outside
3 forms
what are the 3 forms of spina bifida aperta/cystica?
meningocele, myelomeningocele, and myeloschisis
what is meningocele spina bifida?
the least severe spina bifida aperta/cystica where the meninges stick out in a balloon shape in the back with the SC enclosed where it should be
what is myelomeningocele spina bifida?
a cyst contains the SC and spinal root with the Sc not where it is should be
what is myeloschisis spina bifida?
the most severe form of spina bifida aperta/cystica where the SC isn’t formed properly and is exposed
what are the s/s of spina bifida?
motor symptoms in the myotomal pattern
somatosensory symptoms in the dermatomal pattern
autonomic symptoms
what is paresis?
partial loss of voluntary motor contraction, weakness, reduced ability to activate any muscles
what is paralysis?
complete loss of voluntary motor contraction, complete inability to activate muscles
more severe than paresis
is meningocele spina bifida more likely to have LE paresis or paralysis?
paresis
is myelomeningocele spina bifida more likely to have LE paresis or paralysis?
paresis
is myeloschisis spina bifida more likely to have LE paresis or paralysis?
paralysis
what are the somatosensory impairments in meningocele spina bifida?
impaired or absent somatosensation
what are the somatosensory impairments in myelomeningocele spina bifida?
impaired/absent somatosensation
what are the somatosensory impairments in myeloschisis spina bifida?
absent somatosensation
what autonomic s/s may occur in spina bifida?
lack of bowel and bladder control in myelomeningocele or myeloschisis
(sphincter paralysis is what commonly leads to the lack of b/b control)
what may cause spina bifida?
maternal folate deficiency, obesity, diabetes, teratogens, or genetics
what is the biggest risk periods for spina bifida
during week 6 of pregnancy
what are some clinical characteristics of spina bifida?
surgical treatment b4 birth or shortly after birth
may have associations with Arnold-Chiari type 2 and hydrocephalus
what is Arnold-Chiari malformation?
a developmental deformity of the hindbrain where the brain tissue extends into the spinal canal
what brain structures does Arnold-Chiari malformation affect?
cerebellum, brain stem, and upper SC
what is the most sever form of Arnold-Chiari malformation?
type 3
what is type 3 Arnold-Chiari malformation?
the most severe form of Arnold-Chiari malformation where there is an abnormal opening in the back of the skull and the cerebellum and BS structures leak into the opening
higher mortality rate due to severe neurological problems
what is type 1 Arnold-Chiari malformation?
reduced volume of the posterior fossa with cerebellar tonsil herniation
least severe type with mild symptoms exacerbated by coughing/sneezing
what is type 2 Arnold-Chiari malformation?
malformation of the BS and cerebellum that is nearly always associated with spina bifida myelomeningocele or myeloschisis
even smaller posterior fossa with an enlarged pons pushing the medulla and 4th ventricle down
enlarged ventricles causing hydrocephalus
additional s/s of Arnold-Chiari malformation develop due to…
direct compression of neurological structures against the foramen magnum and SC
syringomyelia development
sensory and motor impairments
blocked CSF flow from a blocked foramen magnum
what is a syringomyelia?
fluid filled cavity in the SC that can produce pain, weakness, stiffness and may expand causing SC damage
what is the most common type of Arnold-Chiari malformation?
type 1
which type of Arnold-Chiari malformation is usually found out by accident?
type 1
what are common s/s of Arnold-Chiari malformation?
occipital headache exacerbated by coughing, sneezing, or straining
neck pain
uncoordinated movement
paresis
impaired fine motor in hands
loss of pain and temp sensation on shoulders and lateral upper limbs
restriction of CSF flow leading to visual disturbances and hydrocephalus
CN involvement
what type of Arnold-Chiari malformation is usually asymptomatic?
type 1
what is the classic presentation of a syringomyelia?
a cape like distribution of lost pain and temp sensation over the shoulders and lateral upper limbs
why would restriction of CSF flow cause visual disturbances?
pressure on the optic chiasm
what causes hydrocephalus?
restriction of CSF flow
what s/s can hydrocephalus cause?
vomiting and epilepsy
what CN involvement may present in Arnold-Chiari malformation?
vertigo and facial and eye muscle weakness (CN 7)
how is Arnold-Chiari malformation managed?
muscles relaxants, NSAIDs, and use of a cervical collar may be used for pain
re-establishing CSF flow with a VP or VA shunt
t/f: there is no gait improvement w/medical management of Arnold-Chiari malformation
true
what is a ventriculoperitoneal (VP) shunt?
a catheter is placed in the brain and drains fluid to the lining of the abdomen
what is a ventriculoaterial shunt?
a catheter is placed in the ventricle and drains into the atrium
what is tethered SC?
the end of the SC (fylum of the conus medullaris) adheres to a lower vertebra causing progressive deficits in the LE
why is tethered SC progressive?
as one grows, there will be abnormal stretching of the SC
what are the s/s of tethered SC?
sensory deficit/pain in the saddle region and LE
b/b dysfunction
progressive weakness that can lead to paresis and deterioration of walking
what is spinal muscular atrophy?
an autosomal recessive disorder that causes motor neuron degeneration
what causes spinal muscular atrophy?
deletion of the survival motor neuron (SMN) 1 gene that makes SMN protein to support survival and maintanance of neurons
what happens in spinal muscular atrophy?
progressive weakness and wasting of skeletal muscles
what is type 1 spinal muscular atrophy?
the most severe form
symptoms present at birth or within the 1st 6 months of life
most die b4 their 2nd birthday
what type of SMA makes up 60% of cases?
type 1
what type of SMA are “non-sitters”?
type 1
what is type 2 SMA?
symptoms develop b/w 6-18 months and tends to affect the LE
often live into adulthood
what type of SMA are “sitters”?
type 2
what is type 3 SMA?
symptoms occur after 18 months or some show no signs until early adulthood
mild proximal muscles weakness, frequent, respiratory infections
doesn’t really affect life expectancy
what is type 4 SMA?
rare SMA w/symptoms in late 30s
slow progression
remain mobile well into adulthood
what type of SMA are “walkers”
type 3
what is developmental coordination disorder?
dyspraxia
lack of motor coordination to perform age-appropriate tasks
normal intelligence and no known neuro lesions
what are some s/s of developmental coordination disorder?
clumsiness
lack of balance
frequent falls
difficulty planning and executing movement
slow and inaccurate movement
longer movement planning time
are males of females more frequently diagnosed with developmental coordination disorder?
males
what are the primitive reflexes?
assymetric tonic neck reflex (ATNR)
symmetric tonic neck reflex (STNR)
tonic labyrinth reflex
what are primitive reflexes?
involuntary motor responses originating in the BS to facilitate survival and gradually disappear as the CNS matures
what is the assymetric tonic neck reflex (ATNR)?
elicited by turning the head to one side
the arm and leg on the side that the head is turned toward extend and the limbs on the other side flex
when does the ATNR reflex last until?
4 months postnatally
what is the symmetric tonic neck reflex?
elicited when the neck flexes/extends in sitting or quadruped
neck flexion causes arm flexion and leg extension
how long does the STNR reflex last?
5-6 months to 8-11 months
what is the tonic labyrinth reflex?
elicited when the neck flexes/extends in supine
forward tilting of the head causes shoulder protraction and hip-knee flexion
backward tilting of the head causes shoulder retraction and leg extension and adduction
how long does the tonic labyrinth reflex last?
birth to 4-6 months postnatally
what is the Babinski reflex?
scrape the bottom of a baby’s foot and the toes fan out
how long does the Babinski sign last?
shouldn’t persist longer than 24 months
what is the palmar grasp reflex?
place a finger in a baby’s palm and they squeeze it
pyramidal tract integrity test
how long should the palmar grasp reflex last?
no more than 6 months
what is ataxia?
motor impairment/incoordination not due to muscle weakness
what is the dermatome?
areas of skin innervated by a single nerve root or a part of the somite that gives rise to the skin innervated by the neurons from the neural crest
what is the nerve root innervation of the musculocutaneous nerve?
C5, 6, 7
what is the nerve root innervation of the axillary nerve?
C5, 6
what is the nerve root innervation of the radial nerve?
C5, 6, 7, 8, T1
what is the nerve root innervation of the median nerve?
C5, 6, 7, 8
what is the nerve root innervation of the ulnar nerve?
C8, T1
what is the dermatomal innervation pattern of C5?
the clavicular area down the inner arm to the wrist and back of the lower neck
what is the dermatomal innervation pattern of C6?
top of the shoulder down the arm on the radial side and all of the thumb and back right below C5 innervation
what is the dermatomal innervation pattern of C7?
back right below C6, back of shoulder down the back of the arm and index and middle finger on palmar and dorsal side of hand
what is the dermatomal innervation pattern of C8?
low back of the shoulder/scap down the back of the arm on the ulnar side and the palmar and dorsal side of the ring and pinky fingers
what is the dermatomal innervation pattern of T1?
below the clavicle to armpit area down the middle of the inner arm to the wrist and back of scap below C8 innervation
median nerve peripheral innervation
tips of middle and index fingers and half of ring finger on dorsal side, and thumb, index, and middle fingers and half in ring finger on palmar side
what are the 2 innervation patterns?
- dermatomal innervation
- peripheral innervation
what innervation does a radiculopathy follow?
dermatomal innervation
what is a radiculopathy?
proximal pathology of a nerve root that follows dermatomal and myotomal patterns
what innervation pattern does a neuropathy follow?
peripheral innervation
what is a neuropathy?
distal pathology of a nerve branch
what is double crush phenomenon?
both a radiculopathy and neuropathy present that can cause a different dermatomal pattern
t/f: the intervention is the same for a radiculopathy and a neuropathy?
false!
what is peripheral neuropathy?
loss of sensory and/or motor function
does sensory or motor loss happen first in peripheral neuropathy?
sensory loss
what is the order of sensory loss in peripheral neuropathy?
heavily myelinated large diameter axon neurons damaged 1st (1a/b and A beta-proprioception and light touch)
- proprioception
- light touch
- cold sensation
- fast nociception
- heat
- slow nociception
what is the most common cause of chronic peripheral neuropathy?
diabetic neuropathy
what is carpal tunnel syndrome?
median nerve neuropathy
what are the 3 types of ataxia?
sensory, vestibular, and cerebellar
what is sensory ataxia?
a proprioceptive pathway lesion affecting the DCML
what are the s/s of sensory ataxia?
wide BOS, slow gait, over/undershooting, positive Romberg test
what is a positive Romberg test?
when the patient keeps the eyes open and stand with the feet together, they can balance, but with the eyes closed they cannot
why would someone with sensory ataxia not be able to balance with their eyes closed?
because their is no visual compensation for lost proprioceptive information
what time of day would sensory ataxia coordination be worse?
at night bc the darkness diminished the visual compensation for proprioceptive loss
why can vision only compensate for CONSCIOUS proprioception?
vision is a conscious pathway and so it can only compensate for other conscious pathways, not unconscious ones
where is the first order neuron in the DCML?
periphery to SC
where is the 2nd order neuron in the DCML?
caudal medulla decussation to synapse in the VPL (thalamus)
where is the 3rd order neuron in the DCML?
VPL to S1 (primary somatosensory cortex)
what are the DCML somatosensory modalities?
conscious proprioception and light touch
where does the DCML decussated?
caudal medulla
where does the DCML terminate?
cerebral cortex
where in the thalamus does the DCML go?
VPL
what are the somatosensory modalities of the trigeminal pathway for light touch?
conscious proprioception and light touch
where does the trigeminal pathway for light touch decussate?
pons
where does the trigeminal pathway for light touch terminate?
cerebral cortex
where in the thalamus does the trigeminal pathway for light touch go?
VPM
what makes of the medial system?
DCML and trigeminal pathway for light touch
what makes up the antero-lateral system?
spinothalamic pathway and trigeminal pathway for pain
what are the somatosensory modalities for the spinothalamic pathway?
fast nociception
temp
crude touch
where does the spinothalamic pathway decussate?
in the SC at the level of the 1st order neuron entry
where does the spinothalamic pathway terminate?
cerebral cortex
where in the thalamus does the spinothalamic pathway go?
VPL
what are the somatosensory modalities for the trigeminal pathway for pain?
nociception
temp
crude touch
where does the trigeminal pathway for pain decussate?
caudal medulla
where does the trigeminal pathway for pain terminate?
cerebral cortex
where in the thalamus does the trigeminal pathway for pain go?
VPM
what are the somatosensory modalities of the nonconscious spinocerebellar pathway?
nonconscious proprioception
where does the spinocerebellar pathway decussate?
mostly no decussation, some double decussation
where does the spinocerebellar pathway terminate?
cerebellum
what are the somatosensory modalities of the divergent pathway (medial nociceptive system w/in anterolateral system) ?
slow nociception
where does the divergent pathway decussate?
same as spinothalamic, at the SC at the level of 1st order neuron entry
where does the divergent pathway terminate?
reticular formation
periaqueductal gray
insula
amygdala
dorsolateral prefrontal cortex (DLPFC)
cerebral cortex
with a cortical lesion, what sensory loss is there?
contralateral loss of all sensory modalities (proprioception, light touch, and nociception), decreased stereognosis and impaired graphesthesia
with a thalamus lesion (VPM/VPL), what sensory loss is there?
contralateral sensory loss of the face and body with normal nonconscious proprioception and slow nociception bc the nonconscious and divergent pathways are not affected
what is the most common brain stem stroke?
lateral medullary lesion
what is the 2nd most common brain stem stroke?
lateral pontine lesion
with a lateral pontine lesion, what is the sensory loss of the body?
contralateral loss of pain and temperature sensation in the body (spinothalamic tract)
with a lateral pontine lesion, what is the sensory loss of the face?
ipsilateral loss of pain and temp sensation in the face and ipsilateral loss of discriminitive touch and proprioception in the face
with a lateral medullary lesion, what is the sensory loss of the body?
contralateral loss of pain and temp sensation in the body
with a lateral medullary lesion, what is the sensory loss of the face?
ipsilateral loss of pain and temp sensation, but unaffected touch and proprioception of the face
what is vestibular ataxia?
pathology in vestibular system causing dizziness, vertigo, difficulty hearing, tinnitus, motor incoordination
feels like the world is spinning (may cause vomiting)
what is cerebellar ataxia?
pathology in cerebellum
negative Romberg test (can’t do with eye opened or closed)
lateral hemispheres: finger ataxia
paravermis: limb ataxia
vermis: trunk ataxia
