diff dx neuro - basics Flashcards
in a neurological exam…
what is a negative sign
what is a positive sign
negative sign - reveals a disorder by the absence of what should be present
eg; non-reactive pupils, atrophy, absent reflex
positive sign- reveals a disorder by a finding that should not be present
eg; babinski, spasticity, rigidity
grades for DTR
0-4+
0= absent 1+ = diminished 2+ = normal 3+ = increased 4+ hyperactive
how does root compression affect DTR grade?
how does CNS issue affect DTR grade?
root compression => lower grade
CNS issue => spasticity = higher grade
sensory classifications (what do they lose) peripheral involvement (4) cortical involvement (5)
peripheral sensations inclue…
- light touch
- pain & temp
- proprioception
- vibration
cortical sensations are things that are interpreted…
- 2 point discrimination
- stereognosis
- graphesthesia
- bi-lat simultaneous extinction
- localization
abnormal reflexes & tone clasp knife lead pipe clonus babinski grasp reflex
clasp knife- spasticity = corticospinal lead pipe - rigidity = basal ganglia (PD) clonus = corticospinal tract babinski - corticospinal tract grasp reflex - frontal lobe
motor system & motor control
sherrington reflex model
sensory input => motor output
heirarchial model
control is top down
motor programs drive movement, feedback oriented
motor programming theories
motor engrams exist and become hardwired
eg handwriting is the same on paper and on a board
systems model
bernstein
movements come from integration from all systems, CNS, PNS, musculoskeletal & the environment
apraxia (def)
loss of ability to execute movement
motor homunculus (3)
- the primary motor cortex has lowest threshold of activation
- 1:1 correspondence btwn cells and AHC
- the more you stimulate, the more complex the movement
corticospinal tracts
names
where they originate (which cortex)
which lobe?
- corticobulbar & corticospinal
2. 40-50% of fibers originate in primary motor cortex, located in parietal lobe
CVA most common site appearance (at rest) muscle tone voluntary movement coordination reflexes babinski
most common site- internal capsule appearance (at rest) - normal muscle tone - flacid then spastic voluntary movement- severe weakness, the pathological synergies coordination - poor reflexes- absent then hyperreflexive babinski - absent then heyperreflexive
basal ganglia process appearance (at rest) muscle tone voluntary movement coordination reflexes babinski
process- loss of balance between cholinergic and dopaminergic
appearance (at rest)- rigidity, tremor at rest
muscle tone - rigid
voluntary movement - bradykinesia
coordination - slow
reflexes - normal
babinski - absent
cerebellar dysfunction process appearance (at rest) muscle tone voluntary movement coordination reflexes babinski
process- deficit in coordination, balance and/or hypotonia (depending where lesion is)
appearance (at rest) - normal
muscle tone - normal or decreased
voluntary movement - normal or decreased
coordination - poor with intention tremor
reflexes - swinging or pendular reflex
babinski - absent
LMN process appearance (at rest) (3) muscle tone voluntary movement coordination reflexes babinski
process- all motor functions lost when pathway is damaged or destroyed
appearance (at rest) - atrophy, fasciculations & fibrillations on EMG
muscle tone- decreased
voluntary movement - decreased proportional to extent of lesion
coordination - weak or totally paralyzed
reflexes - absent
babinski - absent
what is a ridiculopathy?
injury to nerve root
motor symptoms of a peripheral neuropathy (5)
- weakness
- absent DTRs
- atrophy
- fibrillations - random discharge of muscle fibers (see on EMG)
- fasciculations - random discharges of MU
5 sensory symptoms of peripheral neuropathy
- numbness, decreased sensation (hypoesthesia)
- pins & needles - parasthesia
- burning - dysethia
- hyperesthesia
- severe deficits can -> sensory ataxia because of loss of proprioception
what paresthesia and dysesthia tell us about fiber involvement
parasthesia = tingling, pins & needles
large fiber involvement
dysesthia = pain
small fiber involvement
4 sympathetic symptoms of peripheral neuropathy
- altered sweating, blood flow & temp
- trophic changes (texture, color, smoothness)
- hair loss, edema, hyperesthesia
- cardiac, GU, GI symptoms
how do sympathetic neuropathic symptoms usually present?
localized to 1 limb
reflex sympathetic dystrophy
a.k.a.
eitology (5)
treatment (3)
a.k.a. complex regional pain syndrome (type I)
eitology:
- tight splint or cast
- localized trauma or surgery
- improper use of a sling
- not elevating limb to reduce edema
- disuse
trx
- use limb** => desensitize
- reduce edema
- progressive, intense, multidisciplinary therapy
neurogenic vs. vascular condition (3 each)
neurogenic:
- dry skin (because sweat glands are peripheral nerves)
- localized trophic changes
- edema can cause nerve compression
vascular:
- majority of limb presents with hair loss, shiny skin or cold
- blue skin (venous insufficiency)
- pale skin (arterial insufficiency)
what does blue skin mean?
what does pale skin mean?
blue skin => venous insufficiency
pale skin => arterial insufficiency
levels of peripheral nerve involvement (3)
- neurapraxia - local conduction block
recovery starts w/i 1 minute of removal of compression - axonotomesis - damage to axon with wallerian degeneration
can occur after 6hrs of intense compression - neurotmesis - damage to axon and one or more protective sheaths
more derangement => more scar tissue
what is wallerian degeneration?
break down of myelin sheath (which is many layers of schwan cells)
5 categories of PNL & causes
1. mononeuropathy from compression, traction or vascular 2. mononeuropathy multiplex = multiple mononeuropathies = discrete lesions of several individual nerves usually vascular 3. polyneuropathies motor, sensory, sensorimotor or autonomic 4. plexopathy - lesion at plexus trauma or tumor 5. ridiculopathy - at root disc or tumor (dosal root = herpes)
classic characteristics of polyneuropathies (2)
- symmetrical sensory loss (stocking & glove presentation)
- affects LE before UE (then progresses)
sensory loss in distal LE -> peripheral -> UE
progression of multiple mononeuropathies
starts with 1 nerve, then => 2, then 3…
usually vascular
metabolic neuropathies (3)
- alcoholic
- diabetes
- uremic (people on HD)
examples of degenerative peripheral neuropathy (2)
- AIDS
2. herpes
