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Robotic Brain Universe

Teaching cases

Every case is fictional and invented for teaching. No case describes a real patient, and the model is the fsaverage template, not anyone's anatomy. Each case sets the model; the answers are on the structure pages, where every statement is sourced.

  1. 1. Small lesion at the left hand knob

    Fictional teaching case

    A fictional right-handed adult has a small lesion on the left precentral gyrus at the knob-shaped hand segment. Locate the region on the template and review its eloquence grade.

    Questions

    • Which deficit would injury to this cortex cause, and on which side of the body?
    • Which arterial territory covers the lateral precentral convexity?
    • What intraoperative technique is used near motor cortex?

    Answers, with sources: precentral gyrus, corticospinal tract

  2. 2. Left inferior frontal gyrus, opercular part

    Fictional teaching case

    A fictional adult has a lesion in the left pars opercularis. Handedness and language dominance have not been tested.

    Questions

    • Why is this region graded eloquent only conditionally?
    • What does the template not tell you about this individual?
    • How variable is the location of essential language sites?

    Answers, with sources: pars opercularis, pars triangularis

  3. 3. Posterior medial superior frontal gyrus

    Fictional teaching case

    A fictional adult has a lesion on the medial surface of the posterior left superior frontal gyrus.

    Questions

    • Which functional area lies here, and what syndrome can follow its resection?
    • How does the time course differ from injury to primary motor cortex?

    Answers, with sources: superior frontal gyrus, precentral gyrus

  4. 4. Left insular lesion

    Fictional teaching case

    A fictional adult has a lesion confined to the left insular cortex. Use the inflated surface to see the insula without the opercula.

    Questions

    • Which arterial branches supply the insula, and which of them reach the corona radiata?
    • Which deep arteries limit resection medially?

    Answers, with sources: insula

  5. 5. Left thalamic lesion

    Fictional teaching case

    A fictional adult has a small lesion in the left thalamus. The cortex is shown as glass.

    Questions

    • Name the four main thalamic arterial territories.
    • Why is the thalamus graded eloquent?

    Answers, with sources: thalamus

  6. 6. Lesion next to the corticospinal tract

    Fictional teaching case

    A fictional adult has a deep left frontal lesion close to the descending motor pathway. Tracts are shown with the cortex as glass.

    Questions

    • Through which structures does the corticospinal tract descend?
    • What is the intraoperative reference for its position, and what role does tractography play?

    Answers, with sources: corticospinal tract, precentral gyrus

Read about this

  • Blood supply and stroke

    The arteries of the brain and their territories, how flow is regulated, what a stroke destroys minute by minute, and the trials that changed treatment.

    Intermediate

  • Language and speech

    Where language lives in the brain, why it is not the same as thought, and how AI language models and speech implants are changing the field.

    Intermediate

  • The motor system

    How the brain turns intention into movement, from the redrawn motor homunculus to the laws of reaching and the technology that restores it.

    Intermediate

  • Brain–computer interfaces

    How implants like BrainGate and Neuralink read intention from motor cortex, the maths of decoding, and the race to restore speech and movement.

    Intermediate