I have neurology exam very soon, so I have to hold my studies for USMLE again but at the mean time I tried to listen to USMLE lectures of neuroscience which is not really helping with my forthcoming neurology exam but I am very impressed I can understand the very basics of neuroscience.
For example today I listened to the lectures about the 3 important tracts in spinal cord. I learned that the motor (corticospinal tract) only needs 2 neurons (UMN + LMN) while sensory (dorsal columns and spinothalamic tract) needs 3 neurons.
The lecture also taught me about the points of decussation and its clinical importance. For example the lesion in spinothalamic tract always manifest itself contralaterally because it decussates almost immediately upon entering the dorsal horn of grey matter. Meaning any pain and temperature loss in a patient always mean a contralateral lesion in spinothalamic tract!
This is very helpful to understand lesions on spinal cord; Brown-Sequard syndrome, Lou Gehrig’s disease, polio, tabes dorsalis etc.
But lesions on any part of brainstem will result in contralateral spastic paresis/ loss of touch sensation/ loss of pain sensation. How to know if this is really a lesion in brainstem? The cranial nerve involvement! For example; Weber’s syndrome = ipsilateral oculomotor nerve palsy (down n’ out) + contralateral hemiparesis/hemiplegia.
June 22, 2008 at 2:34 pm |
i think all those informations were taught during our neuro cycle right?ops, to be more precise- during preparation for the exam…sometimes it’’s easier to understand the basic things first,……so enjoying your summer holiday?Pray for my last paper-internal med on this tuesday