Neurological Syndromes: INBDE Review
The pattern-recognition payoff: Brown-Séquard, ASA infarct, MCA/ACA/PCA strokes, brainstem lesions, cerebellar syndromes, and the aphasias. Each one tied back to the anatomy from 2.1–2.3. 11 board-style MCQs.
Concept summary & clinical relevance.
Quick-reference structure first, then nerve-by-nerve detail. Mnemonics in amber, clinical pearls in blue.
Neurological syndromes are how the INBDE actually tests neuroanatomy: a brief vignette plus a request to localize the lesion. This chapter is the pattern-recognition payoff for everything in 2.1–2.3: vascular territories, brainstem nuclei, cerebellar laterality, and the aphasia patterns that get asked over and over.
| Artery | Classic deficit | Side |
|---|---|---|
| MCA (dominant, usually left) | Aphasia + face/arm hemiparesis | Contralateral motor; language deficits independent of side |
| MCA (non-dominant, usually right) | Hemineglect + face/arm hemiparesis | Contralateral motor + ignores left side of space |
| ACA | Leg > arm weakness; abulia | Contralateral |
| PCA | Homonymous hemianopia (often macular sparing); rarely prosopagnosia | Contralateral visual field |
| Brainstem level | CN deficit | Classic finding |
|---|---|---|
| Midbrain | CN III palsy | Ptosis, “down and out” eye, dilated pupil |
| Pons | CN V and VII palsy | Loss of facial sensation/mastication; facial droop |
| Pons | CN VI palsy | Inability to abduct eye |
| Medulla | CN IX, X, XII deficits | Loss of gag, hoarseness, tongue deviation; respiratory failure if severe |
| Syndrome | Pattern |
|---|---|
| Brown-Séquard (hemicord) | Ipsi motor + ipsi vibration; contra pain/temp (1–2 levels below) |
| Anterior spinal artery (ASA) infarct | Bilateral motor + pain/temp loss; vibration spared |
| Posterior spinal artery (PSA) infarct | Vibration/proprioception loss in isolation |
| Central cord syndrome | Bilateral pain/temp loss; motor + vibration spared |
Cortical stroke syndromes
- MCA territory: face and arm hemiparesis with cortical signs. Dominant hemisphere → aphasia (Broca's, Wernicke's, or global). Non-dominant hemisphere → hemineglect.
- ACA territory: contralateral leg weakness > arm; may produce abulia (loss of motivation/initiative).
- PCA territory: contralateral homonymous hemianopia, often with macular sparing. Rare: prosopagnosia from fusiform gyrus involvement.
Brainstem syndromes
- Midbrain: CN III palsy (ptosis, “down and out” eye, dilated pupil).
- Pons: CN V (facial sensation/mastication) and CN VII (facial expression) deficits; CN VI palsy → inability to abduct.
- Medulla: CN IX/X/XII deficits → swallowing/voice issues, tongue deviation. Severe medullary lesions threaten respiration.
Cerebellar syndromes
- Cerebellar lesions cause ipsilateral signs (the pathway double-crosses).
- Vermis: wide-based, “drunk” gait; trunk ataxia.
- Hemispheres: ipsilateral intention tremor, dysmetria, dysdiadochokinesia.
- Flocculonodular lobe: balance and eye movement disturbance.
Spinal cord syndromes
- Brown-Séquard (hemicord): ipsi motor + vibration loss, contra pain/temp loss 1–2 levels below.
- ASA infarct: bilateral motor + pain/temp loss; vibration/proprioception spared.
- PSA infarct: isolated bilateral vibration/proprioception loss.
- Central cord syndrome: bilateral pain/temp loss with motor + vibration spared.
11 board-style MCQs.
Active recall is the highest-yield study method for the INBDE. Pick an answer, check it, and read why every distractor is wrong, that's where the learning compounds.
The MCQs above are Core Recall, testing what you've memorized. The book adds a full Clinical Integration set: board-style patient scenarios where you apply this anatomy to real clinical reasoning. That's the section the INBDE actually weights heaviest.
- Question 1EasyA lesion affecting only one half of the spinal cord is called:
- Question 2ModerateIn Brown-Séquard syndrome, which function is lost contralaterally below the lesion?
- Question 3ModerateAnterior spinal artery infarct classically spares which sense?
- Question 4ModerateStroke in which artery is most likely to cause aphasia in a right-handed patient?
- Question 5ModerateStroke in the anterior cerebral artery (ACA) most often causes:
- Question 6EasyWhich stroke syndrome causes contralateral visual field loss with preserved motor strength?
- Question 7ModerateNon-dominant (right, in right-handers) MCA stroke is most likely to cause:
- Question 8ModerateWhich cranial nerve deficit is most typical of a midbrain lesion?
- Question 9ModeratePontine lesions often cause deficits in which cranial nerves?
- Question 10EasyCerebellar lesions produce deficits on which side of the body?
- Question 11EasySudden facial droop and inability to produce speech, but with intact comprehension, suggests:
900 INBDE-style MCQs with full explanations across 18 chapters — Core Recall plus board-style Clinical Integration scenarios — alongside Learning Summaries, Integration Bridges, and Review Boxes. Built by Dr. Isaac Sun for dental students who want to think like a clinician, not just memorize.
Founder, KYT Dental Services · Author, KYT INBDE series. These MCQs and Learning Summaries are part of a structural-thinking framework Dr. Sun uses with patients in the chair.