why is there an ipsilateral loss of cortical spinal tract in brown sequard syndrome?

[StrongBeliever]

So I know that the cortical spinal tract crosses to the opposite side at the medulla so when there's a lesion shouldn't it be a contralateral loss instead of an ipsilateral?

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[aymar]

It decussates in medulla which means it travels from the brain on the same side as it supplies, unlike the spinothalamic tract which decussates before ascending. If you lesion the corticospinal tract on the right, it is still located on the right side, and you will therefore lose motor function on the right. Remember that Brown-Sequard is a lesion of the spinal cord itself.

 

[StrongBeliever]

It doesn't decussate until the medulla which means it travels up to the brain on the same side, unlike the spinothalamic tract which decussates before ascending. If you lesion the corticospinal tract on the right, it is still located on the right side, and you will therefore lose motor function on the right. Remember that Brown-Sequard is a lesion of the spinal cord itself.

What do you mean that corticospinal doesn't decussate until the medulla? Doesn't it start from the brain and end in the spinal cord?

 

[Jinglefoot]

Ipsilateral to the lesion my dude

 

[theonlytycrane]

You're thinking that the lesion is contralateral to where the cortical spinal tracts start in the brain, but "ipsilateral" is referring to side of loss in reference to the lesion (at the level of the spinal cord)

 

[aymar]

What do you mean that corticospinal doesn't decussate until the medulla? Doesn't it start from the brain and end in the spinal cord?

misspoke sorry, it a descending tract. point is still the same that it travels through the entire cord on the same side that it supplies. @theonlytycrane explained it well, ipsilateral is in respect to the lesion not the brain

 

[StrongBeliever]

You're thinking that the lesion is contralateral to where the cortical spinal tracts start in the brain, but "ipsilateral" is referring to side of loss in reference to the lesion (at the level of the spinal cord)

misspoke sorry, it a descending tract. point is still the same that it travels through the entire cord on the same side that it supplies. @theonlytycrane explained it well, ipsilateral is in respect to the lesion not the brain

Okay, great! Thank you both!