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.