Grover Flashcards
In an EEG, two electrodes are needed. What are they?
- An active electrode, placed over the site of neural activity
- An indifferent electrode placed at some distance from the active electrode
Frequency of beta waves
13-30 Hz
Frequency of alpha waves
8-13 Hz
Frequency of theta waves
4-8Hz
Frequency of Delta waves
0.5 - 3.5Hz
Smallest amplitude EEG. Associated w/ mental activity. Observed during active, alert wakefulness and REM sleep
Beta waves
Generally associated w/ a state of relaxed wakefullness. Most prominent over the parietal and occipital lobes
Alpha waves
More prominent in young than adult. May be observed during awake, drowsy, and non-REM sleep states
Theta waves
Prominent during non-REM sleep.
Delta waves
Nucleus of trigeminal nerve that carries sensory info from face to synapse in pons.
Carry information about discriminative touch, vibration, and conscious proprioception
Chief Sensory Nucleus
Trigeminal ganglia neurons
Chief sensory nucleus
Spinal trigeminal nucleus
What amplitude is eeg activity that is typically recorded from the scalp?
20-100microvolts
The movement of positive charge into intracellular compartment causes ?
Current sink (Transient local excess of negative charge)
The return flow of current to the Extracellular space creates ?
A current source (transient, local excess of positive charge)
Bc EEG recordings. Reflect the summed activity of neurons, the amplitude is primarily a function of ?
The degree of synchronization w/in the neuronal population being measured
Alpha rhythms are most prominent at ____
Parietal and occipital locations
Specific change in ongoing EEG activity caused by stimulation of a sensory pathway
Sensory evoked potential
Auditory evoked potentials can be used for what ?
Diagnose hearing problems in very small children
Assess brainstem integrity in unconscious or comatose patients
The outward manifestation of a seizure depends ON?
Brain location affected
Seizures restricted to one area of the brain
Partial seizures
Seizures involving abnormal activation of many areas of the brain
Generalized seizures
What happens in a simple partial seizure?
Patient retains consciousness but may experience unusual feelings or sensation (joy, anger, sadness, nausea / hear, smell, taste, see, or feel)
What characterizes a complex partial seizure
Change of consciousness (dreamlike experience or loss of consciousness)
Automatisms (repetitive blinks, twitches, mouth movements)
Warning of an impending seizure
Aura
When a partial seizure starts in one region, but spreads to involve other areas
Secondary generalization
These happen from abnormal neuronal activity that appears synchronously across many parts of brain
Generalized seizures
Loss of consciousness, loss of muscle tone, massive muscle spasms
Generalized seizures
Tonic seizures, clonic seizures, atonic seizures, tonic-clonic seizures, abscence seizuures
Generalized seizuures
Fomerly; petit mal seizures, pt appears to be staring off into space/ muscle jerking or twitching
Absence seizures
Type of seizure characterized by muscles stiffening, mostly in the back, legs, and arms
Tonic seizures
Type of seizure characterized by repetitive jerking movements of muscles bilaterally
Clonic seizures
Type of seizure characterized by both tonic and clonic muscle contractions. Stiffening of body and repeated jerks of the arms and/or legs\ formerly grand mal seizures
Tonic-clonic seizures
Type of seizure characterized by the loss of normal muscle tone.
The patient may fall
Atonic seizures
Ictus
Seizure
Causes of epilepsy
Damage from trauma, stroke, or tumors
Congenital developmental irregularities
Genetic disorders
Definition of pain:
Unpleasant sensory and emotion experience associated with tissue damage
An increase in pain response to a normally painful stimulation
Hyperalgesia
Pain of short duration which resolves w/ healing of damaged tissue
Acute pain
Pain that lasts longer than time for normal healing.
Definition for chronic pain is a fixed amount of time for specific locations..
Chronic pain
Pain caused by damage or dysfunction in any part of. The peripheral or central nervous system
Neuropathic pain
Traumatic neuromas are formed by ?
Proliferating schwann cells and axon sprouts attempting to regrow
Neuropathic pain can result from _____ of peripheral nerves
Injury or inflammation
Nociceptor activators
Potassium
Serotonin
Bradykinin
Histamine
Nociceptor sensitizers
Prostaglandins
Leukotrienes
Substance P (CGRP)
Serotonin
Axon reflex:
Peripheral ends of nociceptors are branched.
Activation of one nociceptor ending sends both orthodromic and antidromic action potentials
Antidromic ones invade nociceptor endings that weren’t originally activated.
The terminals release glutamate. And sometimes substance P or CGRP
An increase in pain response to a normally painful stimulation
Hyperalgesia
Occurs in tissue surrounding site of injury. Caused by peripheral release of chemical activators and sensitizers during axon reflex
Primary hyperalgesia
The extent of primary hyperalgesia correlates with ?
The redness due to vasodilation induced by release of substance P and CGRP (by axon reflex )
Sensation of pain in the absence of any apparent stimulation
Spontaneous pain
Sensation of pain resulting from stimuli which would normally not be capable of causing pain
Allodynia
Pain that lasts longer than the time that it takes for normal healing
Chronic pain
Caused by damage or dysfunction in any part of the PNS or CNS
Neuropathic pain
What are traumatic neuromas?
Trauma to peripheral nerve leads to formation.
Made of proliferating schwann cells and axon sprouts attempting to regrow. Axons can generate inappropriate, spontaneous action potentials
Inappropriate, spontaneous action potentials generated by traumatic neuromas?
Ectopic discharges
What contributes to ectopic discharges originating in both neuromas and in pain at the dorsal root ganglia?
Abnormally increased expression of voltage-gated sodium channels
What contributes to thermal hyperalgesia in peripheral nerve injury?
Peripheral nerve injury increases TRP channel expression in nociceptors
What peripheral mechanism do cyclo-oxygenase inhibitor use to relieve pain (aspirin)
Inhibition in the formation of prostaglandins.
How do corticosteroids relieve pain?
By reducing inflammation, thereby decreasing the production of chemical sensitizers and activators
