Numbness Flashcards
agnosia (steroagnosia)
inabilty to recognize what a sensation is despite relatively normal perception of sensation
when tactile- steroagnosia
Conscious Proprioception
ability to tell where a body part is in space
-largely based on joint position sense
graphesthesia
ability to identify letters or figures traced on skin (without looking)
dermatome
area of skin supplied by nerve root
sclerotome
area of bone and joints supplied by a single nerve root
mytome
muscles supplied by a single nerve root
Radiculopathy
damage to a nerve root (radiculitis is irritation)
myelopathy
damage to the spinal cord from any cause
anesthesia/hypoesthesia
loss (or decrease) in sensation
hyperpathia
exaggerated perception of normally painful stimulated
allodynia
perception of normally innocuous stimuli as being painful
hyperesthesia
excessive sensitivity to any modality
dysesthesia
perception of pain when no stimulus is present
paresthesia
abnormal perception of a sensation in the absence of any stimulus
polyneuropathy
generalized damage to peripheral nerves; usually due to a systemic cause
subjective
relies on patient’s report
3 types of numbness
loss of sensitivty
distorted sensations
damage to NS/manifestation of an underlying painful condition
loss of sensitivty due to
true damage of sensory pathways (anesthesia, hyperesthesia)
distorted sensations
much broader dx- paresthesia (tingling)
damage to NS/manifestation of an underlying painful condition
dysensthesia (perception of an underlying painful condition)
allodynia (perception of innocuous stimuli being painful)
hysterical sensory loss
sensory changes that follow artificial boundaries such as hairline or jawline
things to asscess
broad or vague
all modalities or selective
reflexes
nerve conduction studies
temperature and pin prick
small diameter nerve fibers up STT
vibration
large diameter, heavily myelinated nerve fibers and then dorsal column medial leniscus tracts
one side of body
CNS damage
one side of body, involves same side of face
above the pons
line on body where below sensations are lost
spinal cord lesion
numbness confined to specific nerve or nerve root
peripheral nerve or nerve root damage
loss in upper limbs or upper part of trunk bilaterally with lower limbs and buttocks fine
expanding intraspinal mass
numbness on one side of face
psych disease- perioral paresthesia (does not follow nerve dist)
lateral part of brainstem or upper spinal cord (spinal tract of trigeminal)
–can also produce sensory decrease on one side of head and on the opposite side of body
progession: march of tingling
migraines, focal seizures of sensory cortex
production of distal paresthesia by neck movement or particular neck positions
compressive lesions in cervical region (nerve root or spinal cord)
awakening frm sleep with symptoms
local compression of nerve/compression of circulation in limb
two etiologies of numbness
peripheral (more common) vs central
what are peripheral nerve numbnesses like
assocaited with more localized symptoms and sharper borders between normal and abnormal
causes of peripheral numbness
generalized/focal entrapment neuropathies (distal/symmetryical loss starting in feet)
peripheral entrapment neuropathies
radicuolpathies- small zones (because most dermatones overlap)
brachial plexus lesions
central numbness
bilateral symptoms with a sensory level below which sensation is lost due to damage of tract
WHY CENTRAL NUMBNESS
extrinsic compression (extramedullary)
conditions intrinsically damaging SC (intramedullary)
above foramen magnum..
CV disease, tumors, MS, infectious
[[these are usually unilateral –affecting contralateral side of body; transient]]
