Pain and Temperature Pathways - Stephens Flashcards
What are the two pain pathways?
Paleo (indirect) spinothalamic pathway - slow pain
Neo (direct) spinothalamic pathway - fast pain
If you have no fucking idea what the question is asking except it is referring to pain, what do you answer?
Direct spinothalamic pathway - fast pain
This is the only one that is examined clinically and as we both know, that is Stephens focus in life.
What is the indirect spinothalamic pathway?
1 neuron (C type fiber) in spinal ganglion –> synapses on nucleus proprius, 2 neuron some go to fasciculus proprius, some ascend, some crossover –> 3 neurons synapse in fasciculus proprius and gradually ascend to the Dorsal thalamus
Clinical implications of indirect spinothalamic pathway?
Slow pain, visceral, GVA
NOT examined clinically
-nemesis of pain docs
Unilateral lesion –> no sensory deficits
What is the fasciculus proprius?
The sandy beach area surrounding the dorsal horn
Crazy network of neurons are here, goes all the way up to the thalamus
How are reflexes connected together at different segment levels?
Through the fasciculus proprius
How does visceral pain become sharp?
Even this is C type pain (GVA), if you recruit enough neurons it can become sharp
Can you fix throbbing, achey pain with an anterolateral cordotomy?
NOPE.
This is slow type pain and since it is meandering, you can initially slow it down, but the network is too large to control this way
Can you fix throbbing, achey pain with an anterolateral cordotomy?
NOPE.
This is slow type pain and since it is meandering, you can initially slow it down, but the network is too large to control this way
When Stephens says something synapses in the dorsal thalamus, what specific area is he referencing but rarely states?
Central median nucleus and hypothalamus
You are a neurosurgeon and you are going in to help a patient with intractable pain by performing an anterolateral cordotomy. As you are performing this very specific cut, a hot guy walks by and you break your concentration for a moment. You accidentally cut too much. What are the dire consequences?
You have stopped sharp pain like you wanted to
You have also stopped slow pain and all bowel and bladder control because you cut the fasciculus proprius
((poor bastard will have lots of other issues, but Stephens seems fixated on b/b)
You are a neurosurgeon and you are going in to help a patient with intractable pain by performing an anterolateral cordotomy. As you are performing this very specific cut, a hot guy walks by and you break your concentration for a moment. You accidentally cut too much. What are the dire consequences?
You have stopped sharp pain like you wanted to
You have also stopped slow pain and all bowel and bladder control because you cut the fasciculus proprius
((poor bastard will have lots of other issues, but Stephens seems fixated on b/b)
At what level do you become aware of slow pain?
In the dorsal thalamus (Central median nucleus and hypothalamus), this is as high as it ascends
What is the direct spinothalamic pathway?
1 neuron enters dorsolateral fasciculus of Lissaur and bifurcates - ascends 2 and descends 2
Synapses in substantia gelatinosa
2 neuron from SG crosses over and ascends in the lateral spinal thalamic tract – at the level of the brain stem becomes spinal lemniscus
Synapses in dorsal thalamus - VPL nucleus
3 neuron goes through posterior limb of the internal capsule up to the primary somesthetic cortex
What is the direct spinothalamic pathway?
1 neuron enters dorsolateral fasciculus of Lissaur and bifurcates - ascends 2 and descends 2
Synapses in substantia gelatinosa
2 neuron from SG crosses over and ascends in the lateral spinal thalamic tract – at the level of the brain stem becomes spinal lemniscus
Synapses in dorsal thalamus - VPL nucleus
3 neuron goes through posterior limb of the internal capsule up to the primary somesthetic cortex
Who is gonna geek out soon because it is spring break??
WE ARE!!! I might even watch HP in your honor.
Who is gonna geek out soon because it is spring break??
WE ARE!!! I might even watch HP in your honor.
What does the dorsolateral fasciculus of Lissauer convey?
Pain and temp
What tract carries fast pain as it ascends?
Lateral spinal thalamic tract
—until it reaches the brainstem and becomes spinal lemniscus
