Aaron Rutman, MD Profile picture
Oct 23, 2020 • 7 tweets • 6 min read • Read on X
Neuroanatomy TOTD #9🧵
1/6 The trigeminal n. courses anteriorly➡️prepontine cistern➡️into Meckel’s cave (green), which lies at the medial floor of middle cranial fossa at the petrous apex.
#meded #FOAMed #FOAMrad #neurorad #neurology #neurosurgery #neuroanatomy #neuroanatomyTOTD Image
2/6...Meckel’s cave (MC) is open to the subarachnoid space at its posterior margin (and is therefore filled with CSF). The trigeminal (Gasserion) ganglion lives in MC. Superiomedial to MC (and sharing a dural border), is the cavernous sinus. #radres #neurorad Image
3/6...Coursing anteriorly, the V1 and V2 branches of CNV exit MC to travel within the lateral wall of the cavernous sinus. V3 courses inferiorly to exit the middle cranial fossa through foramen ovale, without involving the cavernous sinus. Image
4/6...Note the vascular variants in the coronal images of the animation. On the right, there is a persistent trigeminal artery (PTA), as well as a fetal PCA. (Saltzman type II for those who care)! #radres #neurorad
5/6...The persistent trigeminal artery (PTA) is most common of the carotid-vertebrobasilar anastomoses (0.1-.6%) - a variant of embryological development. Arises from petrous/cavernous ICA jxn, runs post along CNV/MC, or passes posteriorly at the dorsum sella. #radres #neurorad ImageImage
6/6...Meckel's cave pathology --> large case of trigeminal schwannoma. Note dumbbell shape with post aspect involving the cisternal CNV, and anterior aspect centered in Meckel’s cave (with involvement of adjacent structures). #radres #MedStudentTwitter #MedStudents Image
Note that the first image is mislabeled “trigeminal ganglion” when it should say “trigeminal nerve” as it’s pointing to the cisternal segment! Thanks for pointing it out @LorenzoPinelli

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Aaron Rutman, MD

Aaron Rutman, MD Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @aaronrutman

Dec 8, 2022
HYPOTHALAMUS (HT)🧵-the control center of circadian rhythm, fatigue/wakefulness, hunger/satiety, sex drive, thirst/BP—and the command post for endocrine control via the HT-pituitary axis.
#meded #neuroradiology #neuroscience #radiology #neurology #neurosurgery #neuroanatomy
1/28
Quiz A: Histamine activity in the brain/brainstem contributes to alertness/wakefulness–hence: sleepy effects of benadryl. Histaminergic neurosecretory cell bodies are exclusively in the tuberomammillary nucleus of the TUBER CINEREUM (HT floor), with widespread projections.
2/28
The HT is a mysterious and complex—I get confused sighs from medical students when the topic arises—the small almond-sized morsel is the control center for endocrine/hormone regulation, and homeostasis of food/water consumption, sleep, BP, sex/attachment. The HT is boss!
3/28
Read 29 tweets
May 24, 2022
Pterygopalatine fossa🧵- inspired by ?s from med students in neuroanatomy lab & a resident w/ case of perineural tumor spread on same day! #meded #FOAMrad #medtwitter #medstudents #radiology #neurorad #HNrad #radres #neurology #ENT #temporalbone #neurosurgery #neuroanatomy
1/22
The PTERYGOPALATINE FOSSA (PPF) is a space deep in the face/skull base, bordered anteriorly by the maxilla (max sinus), posteriorly by the pterygoid base of the sphenoid, and medially by the perpendicular plate of the palatine bone. 2/22
It’s best to think of the PPF as a crossroads/intersection. Think about the roads that lead to and from it, and the cast of characters that pass through.

Some like to simplify/visualize the PPF as a cube or inverted pyramid.

3/22
Read 22 tweets
Mar 6, 2021
Neuroanatomy TOTD #15🧵
The inner ear #tweetorial--it packs a large functional punch for its small size-strap in!
#meded #FOAMed #FOAMrad #medtwitter #medstudents #radiology #neurorad #HNrad #radres #neurology #ENT #temporalbone #neurosurgery #neuroanatomy #neuroanatomyTOTD
1/24
To evaluate the t-bone, best to compartmentalize--external/middle/inner ear (IE). See previous #tweetorial of the ME. The IE is difficult as most structures are obliquely oriented (at different obliquities!)-and can be hard to see on standard views. 2/24
IE communicates with ME via oval&round windows (which allow for transmission&dissipation of sonic vibrations). IE houses sensory organs for hearing/balance/sensing motion. The cochlear&vestibular nerves (CNVIII) transmit signals to the brain via the int auditory canal (IAC). 3/24
Read 25 tweets
Jan 11, 2021
Neuroanatomy TOTD #14🧵
Got some requests to do one of the trickiest areas of human anatomy, the #temporalbone. So many named structures! #meded #FOAMed #FOAMrad #medtwitter #medstudents #radiology #neurorad #radres #neurosurgery #neuroanatomy #ENT #otolaryngology

1/21 Image
Whether learning t-bone anatomy as a medical student or evaluating a CT of the t-bone as a radres, it’s best to compartmentalize into external, middle, and inner ear. This thread🧵is on the middle ear: Inner ear to follow, some day:)

2/21 Image
The external ear extends from the external meatus to the TM. The TM should be thin and *almost* imperceptible on CT. Thickened and retracted TM suggests prior pathology (usually otitis media) and scarring.

3/21 Image
Read 22 tweets
Dec 2, 2020
Neuroanatomy TOTD #12

The green structure is the amygdala (amygdaloid body) and the yellow structure is the stria terminalis (ST).

1/18

#meded #FOAMed #FOAMrad #medtwitter #medstudents #radiology #neurorad #radres #neurology #neurosurgery #neuroanatomy #neuroanatomyTOTD Image
Time for a deep dive into limbic networks. Bear with me—this is a fun subject. I got carried away preparing slides—it’s hard to know when to stop!

2/18
The amygdala is an almond-shaped collection of gray nuclei/subnuclei deep to the uncus and ant to hippocampus in the med temporal lobe. Involved in multiple functions: memory modulation, emotional learning and responses, +important connections w/ the olfactory bulb/cortex.

3/18 Image
Read 18 tweets
Nov 15, 2020
Neuroanatomy TOTD #11🧵
➡️intracanalicular facial nerve. IAC cross section➡️4 nerves; ant-sup➡️facial, ant-inf➡️cochlear (7-up/coke-down). Post nerves➡️sup&inf vestibular #medtwitter #meded #FOAMed #FOAMrad #neurorad #radiology #radres #neurology #neurosurgery #neuroanatomy
1/11
Facial motor nucleus is in the pontine tegmentum; axons loop dorsally around the abducens nucleus, then course anterolaterally, exiting the brainstem at the CPA.
2/11
The nervus intermedius (NI) is composed of preganglionic parasympathetic fibers w/cell bodies in the sup salivatory nucleus, taste fibers w/cell bodies in the nucleus solitarius, and somatic sensory input from EAC/external ear, w/cell bodies in the spinal nucleus of CNV.

3/11
Read 11 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

:(