SSEP Flashcards
SSEPs follow an Ascending/Sensory pathway, called the _____ Pathway.
Dorsal Column
Flexion
Bending
decrease angle
Extension
Straightening
increase angle
Abduction
Lateral movement of the limbs away from the median
Adduction
Movement of a limb or eye toward the median
Pronantion
Palm/stomach down
Supination
Palm/stomach up
The DRG contains cell bodies of stimulated _____
Peripheral sensory axons
_____ contains axons carrying evoked signals from lower extremities
Fasciculus Gracilis
_____ contains axons carrying evoked signals from upper extremities
Fasciculus Cuneatus
Fasciculus Cuneatus starts and ascends at _____
T6
Anterior CST passes through the _____
Anterior Funiculus
Lateral CST passes through the _____
Lateral Funiculus
The cervical spinal cord does not have a _____ horn
lateral
The end of the spinal cord is called the _____
conus medularis
The collection of spinal roots at the end of the spinal cord is called the _____
cauda equina
The brainstem consists of the _____, _____, and _____.
Midbrain
Pons
Medulla
1st order neurons synapse at the _____.
Caudal medulla
1st order synapse for lower extremities is the _____
nucleus gracilis
1st order synapse for upper extremities is the _____
nucleus cuneatus
NC and NG decussate via the _____
internal arcuate fibers
Internal arcuate fibers from the NC and NG for the _____ on the contralateral side
medial lemniscus
The medial lemniscal tracts ascend to the _____
VPL of the thalamus
The _____ is the site of the 2nd synapse
VPL of the thalamus
From the VPL, axons pass through the _____ to S1
posterior limb of the internal capsule
_____ is the site of the 3rd synapse
S1, Area 3b of layer IV
Surface electrodes use _____ as a binding agent
Hydrogel on Ag/Ag-Cl
Surface electrodes should be placed _____cm apart
2-3cm
The anode (+) is always placed _____
distal
The cathode (-) is always placed _____
proximal
Current moves from the _____ to the _____
positive (anode)
cathode (negative)
The cathode is where _____ occurs
depolarization
the anode is where _____ occurs
hyperpolarization
The resting membrane potential is at _____
-70mV
If the cathode/anode are placed too close together, you’ll get a _____ amplitude
small
If the cathode/anode are placed too far apart, you’ll get a _____
large stimulus artifact
The stim boxes are _____ current stimulators.
constant
If current is fixed, the machine must provide a higher _____ to compensate for higher resistance. higher _____ = larger _____.
voltage
voltage
stimulus artifact
Cathode placement of median nerve stimulation is between the tendons of the _____ and _____
palmaris longus
flexor carpi radialis
An alternative site for median stimulation is _____, at the _____.
medial to the biceps brachii tendon
cubital fossa
Ulnar nerve stimulation is between the _____ and _____.
flexor carpi ulnaris
ulnar artery
proximal wrist crease
An alternative site for ulnar nerve stimulation is the _____.
medial epicondyle of the humerus
Radial nerve stimulation is just proximal to the _____
lateral epicondyl at the elbow
Posterior tibial nerve stimulation is midway between the _____ and _____.
medial malleolus
achilles tendon
Alternative PTN stimulation is at the _____
popliteal fossa
Peroneal nerve stimulation at the _____, medial to the tendon of the _____.
knee
biceps femoris
Peroneal nerve alternative sites are _____ and _____
medial/lateral malleolus
popliteal space
Femoral nerve stimulation _____
lateral to the femoral artery
Ulnar nerve should be used if at level of _____
5th cervical vertebrae or below
vertebral column is _____ bones
26
_____ cervical vertibrae
7
_____ thoracic vertebrae
12
_____ lumbar vertebrae
5
_____ sacral verebrae
5
_____ coccygeal vertebrae
4
cervical vertebrae have a _____ foramen for the _____.
transverse
vertebral arteries
Cervical vertebrae (-C_) have a _____ spinous process
bifid
cervical plexus is at
c1-4
brachial plexus is at
c5-8
t1
lumbar plexus is at
l1-4
sacral plexus is at
l4-5
s1-4
supraclavicular nerve is at
c3-4
transverse cutaneous nerve is at
c2-3
greater auricular nerve is at
c2-3
lesser occipital nerve is at
c2-3
greater occipital nerve is at
c2
phrenic nerve is at
c3-5
musculocutaneous nerve is at
c5-7
axillary nerve is at
c5-6
radial nerve is at
c5-t1
medial nerve is at
c5-t1
ulnar nerve is at
c8-t1
iliohypogastric nerve is at
l1
illioinguinal nerve is at
l1
genitofemoral nerve is at
l1-2
lateral femoral cutaneous nerve is at
l2-3
obturator nerve is at
l2-4
femoral nerve is at
l2-4
sciatic nerve is at
l4-s3
tibial nerve is at
l4-s3
common peroneal nerve is at
l4-s2
pudendal nerve is at
s2-4
upper stim intensity
15-25mA
lower stim intensity
30-50mA
Upper/Lower pulse width
0.2ms
Upper/lower rep rate
4.7Hz
If SSEPs have low amplitude, you could…
Increase the intensity
Increase the pulse width
Decrease the RR
HFF filters are analagous to ___
LPF
LFF filters are analagous to ___
HPF
Peripheral and cervical responses should be filtered by HFF of ___
1500Hz
Cortical responses should be filtered by HFF of ___
250Hz
Peripheral, cervical, and cortical responses should be filtered by LFF of ___
30Hz
Peripheral and cervical responses should go through a band pass filter of ___
30-1500Hz
Cortical responses should go through a band pass filter of ___
30-250Hz
Notch filters are not recommended for ____
SSEPs
If you are getting a lot of noise in cervical or peripheral responses, you could lower HFF from ___ to ___
1500
1000
Time base for uppers is _
5ms per divison *10
50ms total
Time base for lowers is _
10ms per division *10
100ms total
Recommended trials for recording SSEP average
300 runs
UE N9 is analogous to
erb’s point
UE Obligates (5)
N9 N13 P14 N18 N20
LE Obligates (4)
LP
P31
N34
P37
N20 is the _ response from stimulating UE
cortical
N20 is a _ field response
near
P14 is a _ field response
far
N18 UE is a _ field response
far
N34 LE is a _ field response
far
Stationary potentials have a _, irrespective of their position
constant latency
Propagating potentials have _ depending on electrode position
shifting latencies
N9 (_) is a _ potential
UE propagated
N13 (_) is a _ potential
UE stationary
N13 (_) generator
UE cervical cord
P14 (_) generator
UE Caudal ML
N18 (_) generator
UE Brainstem/Thalamus
N20 (_) generator
UE S1
N9 (_) generator
LE Pop Fossa
LP Generator
Lumbar cord
P31 (_) generator
LE
subcortical
N34 (_) generator
LE
BS
P37 (_) generator
LE
S1
N9 UE channel
active vs ref
EPI vs EPC
N13 UE channel
active vs ref
C5S vs EPC
P14/N18 UE channel
active vs ref
CPI vs EPC
N20 UE channel
active vs ref
CPC vs CPI/Fz
N9 LE channel
active vs ref
PFI vs PFC
P31/N34 LE channel
active vs ref
FPZ vs C5S
P37 LE channel
active vs ref
CPZ vs Fpz
Central conduction time (CCT)
dif in time between 2 points in the CNS
Peripheral conduction time (PCT)
dif in time between 2 points in the PNS
Median SSEP will have a larger or smaller amplitude than ulnar?
larger
Median nerve root levels
C5-T1
Ulnar nerve root levels
C8-T1
supplies ant 2/3 of sc
ASA
supplies post 1/3 of SC
PSA
ASA and PSA arise from
vertebral arteries
supplies blood to structures in and around spinal canal and each level
segmental arteries
segmental arteries arise directly from the
aorta
segmental arteries are called _ in the thoracic region
intercostal arteries
segmental arteries are called _ in the lumbar region
lumbar arteries
branch from the intercostal or lumbar arteries
radicular arteries
PSA radicular arteries are called
radiculopial arteries
ASA radicular arteries are called
radiculomedullary arteries
One radicular artery that connects to ASA forms the _
artery of adamkiewicz
Artery of adamkiewicz arises from _ or _
left inferior intercostal artery
first lumbar artery
Branches of ASA form
sulcal arteries
vessels from both the asa and psa encircle the spinal cord forming a _
pial plexus
vessels of the pial plexus constitute the _
vasocorona
vasocorona provides a _ between ASA and PSA
limited anastomosis
connection
outer disc is called the
annulus fibrosus
inner disc is called the
nucleus pulposus
HNP
herniated nucleus pulposus
removal of softer structers use a
putuitary rongeur
corpectomy
removal of the vertebral body to decrompress
Map
60mmHg
MAP =
DP + 1/3 Pulse Pressure
Pulse pressure =
SP - DP
decadron is a _
steroid
decadron is used to _
suppress inflamatory response
pentobarbital is a _
barbituate
hematocrit
percent of whole blood that is composed of rbc
MAC
minimum alveolar concentration
PAR for SSEP
.75 Mac inhalational agent
<=50%
muscle relaxants ok
narcotics ok
