Evoked Potentials Flashcards
BAER: Abnormal I-III latency
Acoustic neuroma
BAER: Abnormal III-V
MS or adrenoleukodystrophy
Cause of bilateral P100 prolonged latency
Cannot localize, ON, tumor, retina, radiations or degenerative brain disease
Absence of waves I-V in BAER
No interpretation could be technical,
Wave I present but II-V absent
Brain death
Delayed N21 normal N21-P37
Conduction defect proximal to /peripheral to cauda equina
Abnormal N21-P37
Conduction defect above cauda equina but below sensory cortex
Absence of wave V
Defect rostral to pons
Abnormal N13-N20
Above medulla below thalamus
Delayed N21 and N21-P37
Peripheral to cauda equina and below sensory cortex
Delayed P37 absolute latency and abnormal N21-P37 latency
Conduction defect above cauda equina but below sensory cortex
During left tibial SSEP scalp recording electrodes are:
Cz and C3
Transcranial motor stimulation active electrode is
Anode
D wave in transcranial motor stimulate
From direct stimulation of dorsal corticospinal tracks
What can cause prolongation of peripheral cervical and central SSEP
Hypothermia
Etomidate does what to SSEP
Increase amplitude
Inhalational agents do what to SSEP
Decrease amplitude
Preferred click sensation level
65-70 dB
Response fro each ear
2k-4K
Filter for BAER
100-3000 Hz
Age BAERs are like adult
2 yrs
Difference in Baer late cites in baby
Increase
Effect of latency and amp if increase click rate
Increase abs latency and decrease amp
What age can you distinguish awake from sleep
30-34 wks
Baer LFF
50-150
Baer HFF
3000
SSEP LFF
30
SSEP amplification
100000
SSEP HFF
3000
What happens if inadequate stimulation with SSEP
Delayed latencies
