Thread by @drokane

🟢 Mini Neuro Tweetorial #1
🧠 Cortex (Grey cells/axons. Processes. Coms to/from other neurones. Some Higher functions are lateralised).
🧠 LT cortex dom in RT hander
🧠 LT cortex dom in 50% LT handers
What happens if cortical destructive lesion bullet/tumour/bleed/infarct ??

R cortical 🧠 damage causes a clinical subset of 4 things.
👉L Sided Weakness FACE|ARM|TRUNK|LEG ALL same side
👉L Hemisensory reduction/Loss
👉L Homonymous Hemianopia (No vision to LT. Pt looks RT)
👉Right Higher function loss: Extinction/Anosognosia

L cortical 🧠 damage causes a clinical subset of
👉R Sided Weakness FACE|ARM|TRUNK|LEG all same side
👉R Hemisensory reduction/Loss
👉R Homonymous Hemianopia (No vision to RT. Pt looks LT)
👉Left Higher function loss: Language(Dysphasia)

Subcortical 🧠 Damage (Nuclei and Myelinated axons)
👉Contralateral sensory/motor/ataxia
👉No Higher functional loss or hemianopia.
👉Usually due to white matter pathologies

Brainstem: Midbrain Pons Medulla MPM
MIDBRAIN
👉V shaped MR/CT. Limbs of V cerebral peduncles which hold C/spinal fibres.
👉Substantia nigra and red nucleus [Think Colors !].
👉3rd/EW nucleus and below this 4th CN.
👉3rd exits ant btwn V limbs.
👉4th exits pstrly to C/L SO.

Lesion in Midbrain: subset of
👉 Ipsilateral III and C/L hemiparesis (Weber syn)
👉 Ipsilateral rubral tremor
👉 Ipsilateral IV

Pons: looks swollen on CT/MR as axons++ to and from cerebellum traverse. A bridge "pons" over CSF in IVth ventricles behind. Separates it from cerebellum behind. Contains
👉 Corticospinal fibres
👉 CN 5,6,7,8. 6/7 lie close
👉 Axons to/from cerebellum
👉 Sensory fibres
👉 MLF

A lesion will cause a subset of
👉 Contralateral Hemiparesis arm/leg/trunk
👉 Ipsilateral 5/6/7/8 nerve lesion - especially ipsilateral facial weakness and LR palsy
👉 Internuclear ophthalmoplegia
👉 Ipsilateral cerebellar symp/signs

Medulla
Small oval. Corticospinal fibres cross anteriorly. CN 9,10,11,12. Symp trct. Nclus ambig. sensory fibres
Classic Lat med PICA occlusion. Get DWI
👉 Vertigo Hiccups, Dysphagia, Dysarthria
👉 I/L Horner's syn
👉 Ataxia
👉 Pain altered I/L face
👉 Loss pain/temp C/L arm/leg

Basically for Brainstem remember its basically
Cranial nerve palsy + C/L weakness so neuro on both sides. This was all done at one sitting without books so basically a brain dump so please forgive any omissions but generally hope its ok. I will do more later.

WRT Cortex the simple concept point I neglected to state is that the right brain receives sensory input (touch/vision) from left side of your world and outputs all motor to the left side of your world and vice versa.

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