The names of the pathways also tell you a bit about what the pathways do. Ex. Cortico-spinal can be translated to cortex to spine which means it's going from the head to body. You can then deduce this is motor related. Ex. Spinothalamic can be translated to from spine to cortex. You can then assume that this is sensory. If you're short on time, this can at least help you eliminate some choices even if you don't know exactly what it is.
Dude, this is hilarious. I was reading this comment and thought.. wow super helpful, guy must be smart. And then I saw your name and picture !! totally checks out haha
I'm in my second last year of medicine and honestly, I have never understood these concepts as clearly as I do now, after watching your videos. Thank you so much!
These pathways are so forgettable that I have to re-learn it every now and then. These mnemonics make it easier. Btw, my teacher taught me a mnemomic for Brown-Sequard syndrome which makes it very easy that I remember it upto this point. I want to share it. DISC LION DISC is for SENSORY loss (below the lesion) DI = Dorsal column (Ipsilateral), SC = Spinothalamic tract (contralateral) For those wondering what about "At the level of the lesion", it's obvious. You can deduce that there'll be hyperesthesia on the same side, and nothing will happen on the opposite side. LION is for MOTOR loss. LI = Lesion (ipsilateral), ON = Normal (opposite) So, at the level of the lesion, you'll have LMNL and below the level of the lesion, UMNL. Even though motor is said to be "normal" for opposite site of the lesion, there will be some deficit in axial and proximal muscles because of ACST damage.
Good vid but kind’ve counterintuitive on the colorings for the Corticospinal tract where you put the LCST (UMN) in red in writing but the picture that’s up has it as a blue tract, and the Anterior Horn (LMN) is blue in writing but red on the drawing 😅
i passed step 1 dirty!!! i 100% think it was because i discovered your videos 3 days before my test LOL. now i'm watching the rest of them to keep learning in m3 year!
17:14 - Decreased pin prick refers to decreased pain sensation not discriminative touch and would indicate a lateral spinothalamic tract problem, right?
I must have missed something...since the Corticospinal Tract and the Medial Lemniscus decussate in the medulla, aren't their effects contralateral? The video says ipsilateral, so I'm confused. Help!
LST crosses instantly at spinal level, which is why in BSS you'll see contralateral effects for it. The other two tracts cross in Medulla. Their normal functions are contralateral, but BSS will show ipsilateral effects since it is dealing with a spinal (not cortical) injury. Hope that made sense!
question i always get wrong, i had to look up again, is where does it cross in the LST. The answer i am seeing is the Anterior White Commissure. So thinking that in sports, Commissioners allow trades, as this trades sides. Hope this is correct, thanks for this video, helped a ton w the other mnemonics.
Why are there no pain and temp sensation loss at the level of Brown squard lesion? If the signal comes to dorsal nucleus then it need to cross to the opposite side via the lissauer tract which is destroyed…😅 Also I don’t remember adding 2-3 levels when localizing the level of lesion of spinal cord injury using either motor or sensory deficit like in ASIA classification.
when you say that the effect for first two tracts(corticospinal tract and posterior colum) is ipsilateral you say that because of the variation of the decussation of the tract compared to the Spinothalamic tract( as in the decussation for the first two happens in the medulla and the decussation for the lateral spinothalamic tract happens in the spinal cord level). please correct me if im wrong.
Because the first two pathways decussate at the brain stem level (not the spinal cord level) and we're dealing with SPINAL CORD injuries here and so the only pathway among the three that decussate at the SC level is the Spinothalamic (hence its effect is gonna be Contralateral). Hope it helped :)
After doing synapsis with the second neuron, does its axon go by the dorsal column? Or is there a colateral way to the medulla oblongata neuron? I couldn't understand your scheme just at this point...
This is a common feature for any spinal cord lesion, as the UMNs generally act to modulate mainly via inhibition the LMNs. With spinal cord injury, the damaged UMN and LMN at the level cause a LMNL picture at the lesion level, but below this, the LMNs are released from inhibition from the descending UMNs, causing UMNL features below the lesion level. If it helps, I have 2 animated videos on my channel; one on spinal cord injury that helps visualise the UMNL and LMNL issue, and a Brown-Sequard video also
If it helps, I've created an animated Brown-Sequard video on my channel that goes into much more detail. For example, it covers why you also lose spinothalamic loss ipsilaterally approx 2 levels below, then contralaterally all the way down.
3 synapses in DCML pathway : Sensory neuron in the fingers/toes >> Dorsal column nuclei (sensory neuron projects upto the DCN in medulla where it decussates in the medial lemniscus and projects upwards to the thalamus) Dorsal column nuclei >> Thalamus Thalamus >> Primary sensory cortex (cortical centre of the brain responsible for processing all sensory input from the body)
