Stroke Syndromes: Localizing Lesions for Rehab
Chapter 1
Imported Transcript
Claire Brooks
I've got three patients.
Claire Brooks
Patient one has profound right-sided weakness and can't speak fluently.
Claire Brooks
Patient two speaks fluently - maybe too fluently - but doesn't understand much of what I'm saying.
Claire Brooks
Patient three has severe left neglect, keeps running the wheelchair into objects on the left, and insists there's nothing wrong.
Claire Brooks
Same diagnosis?
Claire Brooks
Stroke.
Claire Brooks
Same rehabilitation problem?
Oliver Hart
Not even close.
Oliver Hart
Because "stroke" tells you that brain tissue was injured. It doesn't tell you which network failed.
Oliver Hart
And in rehabilitation, the network matters.
Oliver Hart
A lesion in primary motor cortex gives you a different patient from a lesion in posterior parietal cortex.
Oliver Hart
A dominant superior-division MCA stroke produces a very different rehabilitation picture from a nondominant inferior-division MCA stroke.
Oliver Hart
A pontine stroke may give you cranial nerve findings on one side and weakness on the other.
Oliver Hart
And a cerebellar stroke may leave strength surprisingly intact while devastating someone's ability to walk safely.
Claire Brooks
So if I know the lesion, I should be able to predict the patient.
Oliver Hart
To a degree. And if I know the patient, I should be able to predict the lesion.
Claire Brooks
That's the game today.
Claire Brooks
Localization.
Oliver Hart
But through the physiatrist's lens: Localize the lesion, predict the impairments, then predict the functional consequences.
Oliver Hart
### SEGMENT 1 - THE REHABILITATION VERSION OF NEUROLOCALIZATION
Claire Brooks
Let's establish the difference between an acute neurologic exam and a rehab neurologic exam.
Oliver Hart
In the emergency setting, you may be asking: Is this a stroke? Where is it? What vascular territory is involved?
Oliver Hart
In rehabilitation, imaging has often already answered much of that. So your exam becomes more predictive.
Oliver Hart
You know the lesion. Now ask: What weakness should I see? What sensory deficit? What visual field loss? What aphasia? What neglect? What apraxia? What behavior?
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 3
Oliver Hart
And most importantly: How will those deficits affect mobility, ADLs, communication, safety, and participation?
Claire Brooks
So neuroanatomy stops being trivia.
Oliver Hart
Exactly. Localization becomes functional forecasting.
Oliver Hart
### SEGMENT 2 - BUILD THE MAP BEFORE LEARNING THE SYNDROMES
Claire Brooks
Before arteries, let's orient ourselves to the cortex. Four lobes.
Oliver Hart
Frontal. Parietal. Temporal. Occipital.
Oliver Hart
Then think broadly: The frontal lobe is heavily involved in motor output, motor planning, eye movement, behavior, and language production.
Oliver Hart
The parietal lobe integrates somatosensory information and spatial awareness.
Oliver Hart
The temporal lobe contributes to auditory processing and language comprehension.
Oliver Hart
The occipital lobe processes vision.
Oliver Hart
And none of these functions live completely alone. Motor cortex, sensory cortex, thalamus, basal ganglia, cerebellum, and association networks are densely interconnected.
Claire Brooks
Which explains why a stroke rarely feels like a neat single-function lesion.
Oliver Hart
Exactly. Brains don't read textbook chapter headings.
Oliver Hart
### SEGMENT 3 - PRIMARY MOTOR CORTEX: THE HOMUNCULUS MATTERS
Claire Brooks
Let's start with M1.
Oliver Hart
Primary motor cortex sits in the precentral gyrus, anterior to the central sulcus.
Oliver Hart
And it's somatotopically organized. The medial cortex represents more of the lower limb. The lateral convexity represents upper limb. More inferiorly you find face, tongue, and pharyngeal representation.
Claire Brooks
So immediately I can connect anatomy to vascular territory. Medial frontal cortex?
Oliver Hart
Think ACA.
Claire Brooks
Lateral motor cortex?
Oliver Hart
Think MCA.
Claire Brooks
Which gives us one of the easiest board anchors: ACA weakness is generally leg-predominant. MCA cortical weakness is generally face and upper limb predominant.
Oliver Hart
Exactly. That simple map will carry you through a surprising amount of stroke localization.
Oliver Hart
### SEGMENT 4 - BROCA: LANGUAGE PRODUCTION IS MORE THAN "WORDS"
Claire Brooks
Broca area. Everyone learns: Broca equals expressive aphasia. But the chapter gives us more nuance.
Oliver Hart
Right. Broca area lies in the inferior frontal region of the dominant hemisphere - usually the left.
Oliver Hart
Lesions produce nonfluent language, often with apraxic errors and impaired syntax.
Oliver Hart
But importantly, this is not purely an "output" center. Complex auditory comprehension can also be affected.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 4
Oliver Hart
And the Broca network participates in translating verbal commands into motor activity, so limb apraxia can accompany the lesion.
Oliver Hart
#### HIGH-YIELD LANGUAGE CHECK #1
Claire Brooks
Patient understands the basic conversation, knows what they want to say, but speech is slow, effortful, and nonfluent.
Oliver Hart
Broca-pattern aphasia.
Claire Brooks
Can they repeat normally?
Oliver Hart
Usually not in a classic Broca syndrome.
Claire Brooks
Can comprehension be completely normal?
Oliver Hart
It may be relatively preserved, but complex syntax can be impaired.
Oliver Hart
### SEGMENT 5 - FRONTAL EYE FIELDS: WHY THE PATIENT LOOKS TOWARD THE LESION
Claire Brooks
This one causes residents problems. A large hemispheric stroke and the patient is staring toward one side. Which side?
Oliver Hart
With a destructive frontal eye-field lesion, the eyes tend to deviate toward the cerebral lesion and therefore away from the hemiplegic side.
Oliver Hart
Nondominant frontal lesions can also reduce exploratory eye movements into the contralateral space and contribute to neglect.
Claire Brooks
So right hemispheric stroke - eyes may favor the right - left hemiplegia.
Oliver Hart
Correct. Think: The cortex looks at the lesion. At least as a useful cortical-stroke memory device.
Oliver Hart
### SEGMENT 6 - PRIMARY SENSORY CORTEX
Claire Brooks
Postcentral gyrus.
Oliver Hart
Primary somatosensory cortex.
Oliver Hart
A cortical S1 lesion can disrupt higher-order discriminative sensation - things like two-point discrimination and stereognosis on the contralateral side.
Oliver Hart
If deeper pathways or thalamic structures are involved, you can see broader sensory loss including pain, temperature, and position sense.
Claire Brooks
Which is useful because dense loss of every sensory modality makes me think beyond a tiny cortical lesion.
Oliver Hart
Exactly.
Oliver Hart
### SEGMENT 7 - OCCIPITAL CORTEX: THE HEMIANOPSIA PATTERN
Claire Brooks
Visual cortex.
Oliver Hart
Medial occipital lobe. Unilateral injury classically causes a contralateral homonymous hemianopsia.
Claire Brooks
Right occipital stroke?
Oliver Hart
Left visual field loss in both eyes.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 5
Claire Brooks
And visual field loss is not neglect.
Oliver Hart
Very important distinction. Hemianopsia is a sensory visual-field deficit. Neglect is an attentional disorder.
Oliver Hart
A patient with hemianopsia may know the field is missing and learn compensatory scanning. A patient with severe neglect may behave as though that side of the world doesn't meaningfully exist.
Oliver Hart
### SEGMENT 8 - POSTERIOR PARIETAL CORTEX: WHERE SPACE BECOMES MEANINGFUL
Claire Brooks
This is the rehab-heavy cortex. Posterior parietal.
Oliver Hart
Absolutely. It integrates visual, somatosensory, and auditory information to construct a spatial model of the world and the body within it.
Oliver Hart
Right parietal injury can produce severe left neglect.
Oliver Hart
And beyond neglect: spatial disorientation, constructional apraxia, dressing apraxia, difficulty organizing objects in space.
Claire Brooks
And those are massive occupational therapy problems.
Oliver Hart
Exactly. You can have decent strength and still be profoundly dependent because your spatial map of the body and environment is broken.
Oliver Hart
### SEGMENT 9 - WERNICKE AREA: FLUENT DOES NOT MEAN FUNCTIONAL
Claire Brooks
Now Wernicke.
Oliver Hart
Located posterior to primary auditory cortex in the dominant hemisphere. It processes spoken and written symbolic language into meaning.
Oliver Hart
A lesion produces impaired comprehension and typically fluent aphasia with paraphasic errors. And patients often have poor awareness of their language deficit.
Claire Brooks
So the patient may produce a lot of speech -
Oliver Hart
- but the information content may be poor.
Claire Brooks
That can fool people who equate verbal output with communication competence.
Oliver Hart
Exactly. Quantity of language is not quality of communication.
Oliver Hart
### SEGMENT 10 - ANGULAR GYRUS AND THE WRITTEN WORD
Claire Brooks
Angular gyrus.
Oliver Hart
Posterior to Wernicke area. It integrates visual information into language processing. Lesions can cause alexia.
Oliver Hart
### SEGMENT 11 - ARCUATE FASCICULUS: THE REPEAT-BACK HIGHWAY
Claire Brooks
Broca talks. Wernicke understands. What connects them?
Oliver Hart
The arcuate fasciculus. It's a reciprocal white-matter pathway between those language regions.
Oliver Hart
Damage can impair repetition and may also produce bilateral limb apraxia.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 6
Claire Brooks
So the classic conceptual triad: Broca - nonfluent. Wernicke - fluent but poor comprehension. Arcuate fasciculus - repetition particularly impaired.
Oliver Hart
That's a useful starting framework.
Oliver Hart
### SEGMENT 12 - INTERNAL CAPSULE: SMALL LESION, BIG MOTOR DEFICIT
Claire Brooks
Now subcortex. Posterior limb of internal capsule. Why is this clinically dramatic?
Oliver Hart
Because corticospinal fibers are packed densely together. A relatively small lesion can produce profound contralateral weakness involving face, arm, and leg.
Claire Brooks
So a small deep infarct can look motorically worse than a larger cortical infarct.
Oliver Hart
Absolutely. Location beats volume.
Oliver Hart
### SEGMENT 13 - THALAMUS: THE SENSORY HUB
Claire Brooks
Thalamus.
Oliver Hart
Think sensory relay and integration. Somatosensory. Visual. Auditory.
Oliver Hart
Thalamic lesions can give you sensory loss, pain syndromes, hemiataxia, and sometimes mild motor or cognitive-language findings depending on the region involved.
Claire Brooks
And this sets us up for one of the classic lacunar syndromes later. Pure sensory stroke.
Oliver Hart
Exactly.
Oliver Hart
### SEGMENT 14 - NOW GIVE THE MAP BLOOD
Claire Brooks
Cortex mapped. Now arteries.
Oliver Hart
Three major systems enter the circle of Willis: right internal carotid, left internal carotid, and basilar artery posteriorly.
Oliver Hart
From the carotids arise the ACA and MCA. The basilar divides into the PCAs. And communicating arteries complete the circle.
Claire Brooks
Although "textbook perfect" circle-of-Willis anatomy is not actually universal.
Oliver Hart
Correct. Vascular variation is common.
Oliver Hart
### SEGMENT 15 - ANTERIOR CHOROIDAL ARTERY: THE SMALL ARTERY WITH A BIG JOB
Claire Brooks
Anterior choroidal artery. Why do I care?
Oliver Hart
Because it supplies strategically important deep structures, including portions of the optic pathway and posterior limb of the internal capsule.
Oliver Hart
So a lesion can cause contralateral hemiplegia and visual-field abnormalities depending on which structures are involved.
Oliver Hart
### SEGMENT 16 - ACA SYNDROME: THINK LEG, INITIATION, FRONTAL BEHAVIOR
Claire Brooks
Now the big vascular syndromes. ACA. Give me the headline.
Oliver Hart
Leg-predominant weakness plus medial frontal dysfunction.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 7
Oliver Hart
Unilateral ACA infarction typically causes contralateral hemiplegia that is worse in the leg and shoulder than in the hand and face. Sensory loss tends to be limited compared with the motor deficit.
Claire Brooks
Why leg more than face?
Oliver Hart
Because ACA supplies medial frontal cortex where the leg representation of the motor homunculus lives.
Oliver Hart
#### ACA AND MOTOR INITIATION
Claire Brooks
But the ACA syndrome isn't just a weirdly distributed hemiplegia.
Oliver Hart
Correct. Medial frontal structures include supplementary motor regions and cingulate cortex.
Oliver Hart
Damage can reduce initiation. At the severe end, you can see psychomotor bradykinesia and even mutism. That can be confused with aphasia.
Claire Brooks
That's a fantastic rehab distinction. Patient isn't talking. Maybe they can't produce language. Or maybe they aren't initiating behavior.
Oliver Hart
Exactly. Same surface behavior. Different mechanism. Different treatment strategy.
Oliver Hart
#### HIGH-YIELD ACA CHECK
Claire Brooks
Stroke patient. Right leg profoundly weak. Right hand only mildly affected. Minimal sensory loss. Very reduced initiation. What territory?
Oliver Hart
Left ACA is strongly suggested.
Oliver Hart
### SEGMENT 17 - MCA: THE STROKE TERRITORY YOU MUST OWN
Claire Brooks
If there is one artery PM&R residents need to understand cold -
Oliver Hart
Middle cerebral artery.
Oliver Hart
It supplies a huge portion of the lateral cerebral hemisphere plus important deep structures through lenticulostriate branches.
Claire Brooks
And we need to divide this into mainstem, superior division, and inferior division.
Oliver Hart
Exactly. Because they create very different patients.
Oliver Hart
### SEGMENT 18 - MAINSTEM MCA: THE BIG ONE
Claire Brooks
M1 occlusion.
Oliver Hart
Potentially devastating. A mainstem MCA infarct can affect motor cortex, sensory cortex, internal capsule, visual radiations, language networks if dominant, and attention and spatial networks if nondominant.
Oliver Hart
Complete contralateral hemiplegia and hemisensory loss are common major findings.
Oliver Hart
#### DOMINANT MCA
Claire Brooks
Dominant hemisphere - usually left. What's the language picture?
Oliver Hart
A sufficiently large mainstem infarct can produce global aphasia: reduced fluency, severely impaired comprehension, impaired repetition, impaired reading, and impaired writing.
Oliver Hart
Because multiple components of the language network are injured simultaneously.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 8
Oliver Hart
#### NONDOMINANT MCA
Claire Brooks
Right hemisphere?
Oliver Hart
Now think severe left neglect, spatial disorientation, constructional apraxia, dressing apraxia, reduced attention to left hemispace, reduced exploratory behavior into the left hemispace, and potentially anosognosia - the patient may deny that deficits exist.
Claire Brooks
Which is terrifying functionally. A patient can be physically strong enough to stand and cognitively unaware enough to make standing dangerous.
Oliver Hart
Exactly.
Oliver Hart
### SEGMENT 19 - SUPERIOR-DIVISION MCA: MOTOR PLUS BROCA
Claire Brooks
Superior division.
Oliver Hart
Frontal-lobe convexity. Think arm and hand weakness greater than leg weakness.
Oliver Hart
Some discriminative sensory impairment may accompany it. Visual fields are often relatively spared.
Claire Brooks
Dominant superior division?
Oliver Hart
Broca aphasia. Decreased speech fluency. Apraxic errors. Impaired repetition. Comprehension relatively better preserved. Limb apraxia may accompany the syndrome.
Claire Brooks
Nondominant superior division?
Oliver Hart
Neglect, reduced exploration, visuospatial deficits, and loss or reduction of emotional prosody.
Oliver Hart
### SEGMENT 20 - INFERIOR-DIVISION MCA: LANGUAGE WITHOUT PARALYSIS
Claire Brooks
Inferior division is one of my favorite localization traps. Why?
Oliver Hart
Because the patient may not be weak.
Oliver Hart
Inferior-division MCA infarction primarily affects lateral temporal, parietal, and occipital cortex. So motor cortex may be spared.
Oliver Hart
The patient can have profound neurologic dysfunction while moving all four limbs.
Oliver Hart
#### DOMINANT INFERIOR MCA
Claire Brooks
What's the syndrome?
Oliver Hart
Wernicke aphasia. Fluent speech. Paraphasic errors. Poor comprehension of spoken and written language.
Claire Brooks
So someone can look physically fantastic and still require significant rehabilitation because communication is profoundly impaired.
Oliver Hart
Absolutely.
Oliver Hart
#### NONDOMINANT INFERIOR MCA
Claire Brooks
Right inferior division?
Oliver Hart
Neglect and perceptual deficits. And sensory aprosodia, or affective agnosia - difficulty understanding the emotional meaning conveyed through another person's tone of voice.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 9
Oliver Hart
### RAPID-FIRE MCA ROUND
Claire Brooks
Arm greater than leg weakness plus Broca aphasia.
Oliver Hart
Dominant superior-division MCA.
Claire Brooks
Fluent speech, terrible comprehension, no major weakness.
Oliver Hart
Dominant inferior-division MCA.
Claire Brooks
Dense hemiplegia plus global aphasia.
Oliver Hart
Large dominant mainstem MCA.
Claire Brooks
Dense hemiplegia plus severe neglect and anosognosia.
Oliver Hart
Large nondominant MCA.
Claire Brooks
No major motor deficit, but neglect and visuospatial dysfunction.
Oliver Hart
Nondominant inferior-division MCA.
Oliver Hart
### SEGMENT 21 - PCA: THINK VISION, SENSATION, DISCONNECTION
Claire Brooks
Posterior cerebral artery.
Oliver Hart
Think occipital lobe, medial temporal structures, posterior callosum, and thalamic branches.
Oliver Hart
A PCA infarct can produce contralateral homonymous hemianopsia. If thalamic territory is involved, prominent sensory symptoms can occur.
Claire Brooks
This one is board candy. Alexia without agraphia.
Oliver Hart
The patient can write - but cannot read.
Oliver Hart
This can occur with a left occipital PCA infarct plus posterior callosal disconnection.
Oliver Hart
The left visual cortex is injured, producing a right homonymous hemianopsia. Meanwhile, visual information reaching the intact right visual cortex cannot effectively transfer across the damaged posterior corpus callosum to the dominant language network.
Oliver Hart
Writing remains intact because language-to-motor output pathways are preserved.
Claire Brooks
That's one of the cleanest examples of a disconnection syndrome.
Claire Brooks
#### ANTON SYNDROME
Claire Brooks
Bilateral PCA infarction?
Oliver Hart
Can produce cortical blindness with visual anosognosia - Anton syndrome. The patient is blind but lacks awareness of the blindness.
Oliver Hart
### SEGMENT 22 - LACUNAR STROKES: SMALL BUT HIGH-YIELD
Claire Brooks
Now lacunes.
Oliver Hart
Lacunar infarcts are small lesions, typically related to small-vessel disease. The key learning point is that they produce compact, stereotyped syndromes because they involve tightly packed deep pathways.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 10
Oliver Hart
#### PURE SENSORY STROKE
Claire Brooks
Pure sensory.
Oliver Hart
Numbness involving face, arm, and leg on one side without motor or cognitive deficits. Classically thalamic.
Oliver Hart
Some patients later develop central poststroke pain.
Oliver Hart
#### PURE MOTOR HEMIPARESIS
Claire Brooks
Pure motor.
Oliver Hart
Weakness of face, arm, and leg on one side without cortical signs like aphasia, visual deficit, or apraxia.
Oliver Hart
Common locations include posterior limb of internal capsule, cerebral peduncle, and basis pontis.
Oliver Hart
Functional prognosis may be relatively favorable because cortical cognitive-language deficits are absent.
Claire Brooks
That's an important rehab concept. Two people can have equally dramatic weakness, but the person without neglect, aphasia, or apraxia may have a very different recovery trajectory.
Oliver Hart
Exactly. Motor severity alone does not determine rehabilitation complexity.
Oliver Hart
#### DYSARTHRIA-CLUMSY HAND
Claire Brooks
Name says it all?
Oliver Hart
Mostly. Dysarthria. Facial weakness. Clumsy or mildly weak hand and upper limb. Often from a small pontine or internal-capsule-region infarct.
Oliver Hart
#### ATAXIC HEMIPARESIS
Claire Brooks
Ataxia plus weakness on the same side?
Oliver Hart
Yes. And functionally, dynamic balance can be a major barrier even when strength improves. The ataxic component may improve faster than the hemiparesis.
Oliver Hart
#### SENSORIMOTOR STROKE
Claire Brooks
Motor plus sensory.
Oliver Hart
Often near the junction of thalamus and internal capsule. Contralateral motor and sensory loss together.
Oliver Hart
### SEGMENT 23 - NOW GO BELOW THE TENTORIUM
Claire Brooks
Okay. Everything above was cerebral. Now brainstem and cerebellum. This is where neurology becomes cruel.
Oliver Hart
Or beautiful. Depending on how much coffee you've had.
Claire Brooks
Fair. What's the principle?
Oliver Hart
The brainstem is densely packed. Long motor tracts. Long sensory tracts. Cranial nerve nuclei. Eye-movement pathways. Autonomic pathways. Arousal systems. Cerebellar connections.
Oliver Hart
So a small lesion can produce a very distinctive constellation of findings.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 11
Oliver Hart
Think of the brainstem as the communication superhighway between cerebrum, cerebellum, and spinal cord.
Oliver Hart
### SEGMENT 24 - THE BRAINSTEM LOCALIZATION TRICK: CROSSED SIGNS
Claire Brooks
Give me the brainstem trick.
Oliver Hart
Ipsilateral cranial nerve deficit plus contralateral body deficit.
Oliver Hart
Cranial nerve nuclei and fascicles usually produce findings on the side of the brainstem lesion. Long motor and sensory tracts may produce deficits in the opposite body.
Claire Brooks
So left facial sensory loss plus right body pain-temperature loss - brainstem alarm bells.
Oliver Hart
Exactly. "Crossed findings" should make you think brainstem.
Oliver Hart
### SEGMENT 25 - CORTICOSPINAL TRACT: KNOW WHERE IT CROSSES
Claire Brooks
Motor tract.
Oliver Hart
Corticospinal fibers descend from cortex. Approximately ninety percent cross at the pyramidal decussation near the spinomedullary junction.
Oliver Hart
That matters enormously for localization. A lesion above the decussation tends to produce contralateral weakness. A spinal-cord lesion below the decussation tends to produce ipsilateral weakness.
Oliver Hart
### SEGMENT 26 - SPINOTHALAMIC TRACT
Claire Brooks
Pain and temperature.
Oliver Hart
Lateral spinothalamic tract. Crude touch and pressure are associated with the anterior component.
Oliver Hart
These fibers cross very early after entering the spinal cord and then ascend contralaterally.
Oliver Hart
So in a lateral brainstem lesion, you can get contralateral body pain and temperature loss.
Oliver Hart
### SEGMENT 27 - MLF: THE EYE-MOVEMENT HIGHWAY
Claire Brooks
Medial longitudinal fasciculus. Residents memorize it for one thing.
Oliver Hart
Internuclear ophthalmoplegia.
Oliver Hart
The MLF coordinates conjugate gaze by connecting abducens-related circuitry with oculomotor nuclei.
Oliver Hart
A lesion can impair adduction of one eye during horizontal gaze while the opposite abducting eye develops nystagmus.
Oliver Hart
### SEGMENT 28 - MIDBRAIN: THINK THIRD NERVE PLUS LONG TRACTS
Claire Brooks
Midbrain syndrome. Give me the framework without making me memorize six French and German neurologists.
Oliver Hart
That's the right approach. Think cranial nerve III, red nucleus and cerebellar pathways, corticospinal tract, sensory tracts, and vertical gaze pathways.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 12
Oliver Hart
So a midbrain lesion may combine ipsilateral oculomotor palsy - ptosis, outward-deviated eye, dilated pupil - with contralateral weakness or ataxia depending on the exact structures involved.
Claire Brooks
Classic Weber pattern?
Oliver Hart
Ipsilateral third-nerve palsy plus contralateral hemiparesis.
Claire Brooks
Benedikt-type pattern?
Oliver Hart
Third-nerve palsy plus contralateral tremor, dysmetria, or ataxia from red-nucleus-region involvement, often with additional long-tract findings.
Claire Brooks
Parinaud?
Oliver Hart
Dorsal rostral midbrain. Prominent vertical gaze dysfunction, particularly upgaze.
Oliver Hart
### SEGMENT 29 - PONS: SIX, SEVEN, EIGHT, GAZE, AND MOTOR TRACTS
Claire Brooks
Pons.
Oliver Hart
Think cranial nerves VI, VII, and VIII. Horizontal gaze circuitry. Middle cerebellar peduncle. Corticospinal tract. Sensory pathways.
Claire Brooks
Medial versus lateral?
Oliver Hart
Medial pontine lesions often hit corticospinal and medial lemniscus pathways: contralateral weakness and contralateral loss of vibration and proprioception.
Oliver Hart
Lateral pontine lesions more often involve trigeminal sensory pathways, vestibular structures, facial nerve structures, cerebellar connections, and spinothalamic tract.
Oliver Hart
So you can see ipsilateral facial findings with contralateral body pain-temperature deficits.
Oliver Hart
### SEGMENT 30 - LOCKED-IN SYNDROME
Claire Brooks
We need to spend time here. Locked-in syndrome.
Oliver Hart
Absolutely. A major basilar-artery infarction can damage the ventral pons bilaterally.
Oliver Hart
The corticospinal tracts are interrupted. The corticobulbar tracts are interrupted.
Oliver Hart
The result can be tetraplegia and severe paralysis of cranial-nerve-mediated voluntary movement.
Oliver Hart
If horizontal gaze circuitry is also damaged, horizontal eye movements may be lost while vertical eye movements remain.
Oliver Hart
But consciousness is preserved because rostral arousal systems remain intact.
Claire Brooks
Which means the terrifying part is: the patient may be completely aware.
Oliver Hart
Yes. Cognition and consciousness may be far more intact than motor output suggests. Communication may depend on eye movement or blinking.
Claire Brooks
So before anybody labels the patient "unresponsive" -
Oliver Hart
Establish a reliable communication channel. Vertical gaze. Blinking. Eye-coded yes/no. Then augmentative communication technology when possible.
Oliver Hart
This is one of the most consequential localization-to-function translations in neurorehabilitation.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 13
Oliver Hart
### SEGMENT 31 - MEDULLA: SWALLOWING, VOICE, SENSORY CROSSING, AUTONOMICS
Claire Brooks
Medulla.
Oliver Hart
Now you're near structures crucial for swallowing, phonation, airway protection, vestibular function, tongue control, descending sympathetic pathways, pain-temperature pathways, and corticospinal fibers.
Oliver Hart
So medullary strokes can have enormous rehabilitation consequences even without major cortical dysfunction.
Oliver Hart
### SEGMENT 32 - WALLENBERG: BUILD IT FROM THE ANATOMY
Claire Brooks
The classic. Lateral medullary - Wallenberg syndrome. Don't give me a mnemonic. Build it.
Oliver Hart
Okay.
Oliver Hart
Vestibular nuclei involved: vertigo, nausea, vomiting, nystagmus.
Oliver Hart
Nucleus ambiguus - cranial nerves IX and X motor function: dysphagia, dysphonia, palatal and pharyngeal weakness.
Oliver Hart
Spinal trigeminal pathway: ipsilateral facial pain-temperature loss.
Oliver Hart
Spinothalamic tract: contralateral body pain-temperature loss.
Oliver Hart
Spinocerebellar pathways: ipsilateral limb and gait ataxia.
Oliver Hart
Descending sympathetic fibers: ipsilateral Horner syndrome.
Claire Brooks
That is one beautiful lesion. Ipsilateral face. Contralateral body. Bulbar dysfunction. Ataxia. Horner.
Oliver Hart
Exactly. And from a PM&R standpoint, swallowing may be the most urgent functional issue.
Oliver Hart
#### RAPID-FIRE WALLENBERG ROUND
Claire Brooks
Left lateral medullary stroke. Face pain and temperature?
Oliver Hart
Reduced on the left.
Claire Brooks
Body pain and temperature?
Oliver Hart
Reduced on the right.
Claire Brooks
Horner syndrome?
Oliver Hart
Left.
Claire Brooks
Limb ataxia?
Oliver Hart
Left.
Claire Brooks
Dysphagia?
Oliver Hart
Common because of nucleus ambiguus involvement.
Oliver Hart
### SEGMENT 33 - MEDIAL MEDULLARY SYNDROME
Claire Brooks
Medial medulla.
Oliver Hart
Now think hypoglossal nerve, corticospinal tract, medial lemniscus.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 14
Oliver Hart
So you can see ipsilateral tongue weakness, contralateral hemiplegia, and contralateral impairment in touch and proprioception.
Claire Brooks
Different from lateral medulla because pain-temperature loss and vestibular-bulbar findings dominate laterally.
Oliver Hart
Exactly.
Oliver Hart
### SEGMENT 34 - THE CEREBELLUM: STRENGTH CAN BE NORMAL AND WALKING CAN BE IMPOSSIBLE
Claire Brooks
Cerebellum.
Oliver Hart
Think coordination. Timing. Scaling. Balance. Error correction. Motor learning.
Oliver Hart
The cerebellum modulates movement - it doesn't directly generate corticospinal strength.
Oliver Hart
So someone may test surprisingly well on isolated manual strength testing and still be unable to walk safely.
Oliver Hart
#### THREE CEREBELLAR PEDUNCLES
Claire Brooks
Superior, middle, inferior. Give me just enough to survive boards.
Oliver Hart
Superior is a major output pathway from cerebellum toward red nucleus and thalamic-motor networks.
Oliver Hart
Middle carries major pontocerebellar input.
Oliver Hart
Inferior connects medulla, vestibular, and spinal inputs with cerebellum.
Claire Brooks
So damage produces combinations of ipsilateral coordination and balance problems.
Oliver Hart
Correct.
Oliver Hart
### SEGMENT 35 - CEREBELLAR STROKE PRESENTATION
Claire Brooks
What's the classic clinical cluster?
Oliver Hart
Vertigo. Headache. Vomiting. Gait ataxia.
Claire Brooks
And why are cerebellar strokes dangerous beyond the coordination problem?
Oliver Hart
Because posterior-fossa swelling can compress the brainstem or obstruct CSF pathways.
Oliver Hart
So a patient who initially "just looks dizzy and ataxic" can deteriorate.
Oliver Hart
### SEGMENT 36 - THE PHYSIATRIST'S FUNCTIONAL TRANSLATION
Claire Brooks
Let's step away from pure neurology. Suppose imaging says: right MCA stroke. What should the rehab team immediately anticipate?
Oliver Hart
Potential left hemiparesis. Left sensory impairment. Left neglect. Visuospatial dysfunction. Poor body-environment orientation. Potential anosognosia. Potential left visual-field impairment. And depending on lesion distribution, reduced emotional prosody.
Oliver Hart
Then translate each one.
Oliver Hart
Neglect affects wheelchair navigation, dressing, grooming, reading, safety, transfer setup, wheel positioning, and environmental scanning.
Oliver Hart
Anosognosia increases fall risk.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 15
Oliver Hart
Visuospatial dysfunction affects stair negotiation, mobility, and object manipulation.
Claire Brooks
So knowing the syndrome tells you what to actively search for before therapy discovers it the hard way.
Oliver Hart
Exactly.
Oliver Hart
### CASE 1 - DOMINANT SUPERIOR MCA
Claire Brooks
Case time. Sixty-eight-year-old right-handed patient with acute left hemispheric stroke.
Claire Brooks
Right face and arm are much weaker than the right leg. Speech is effortful. Comprehension is relatively preserved. Repetition is impaired. Visual fields are intact. Localization?
Oliver Hart
Dominant superior-division MCA.
Claire Brooks
Most likely aphasia?
Oliver Hart
Broca pattern.
Claire Brooks
Rehab concerns?
Oliver Hart
Upper-extremity function. Communication. Limb apraxia. Potential frustration from preserved awareness. And safety despite relatively better lower-extremity function.
Oliver Hart
### CASE 2 - DOMINANT INFERIOR MCA
Claire Brooks
Next. Patient moves all four limbs. Speech is fluent. They answer questions with long strings of words, but the responses often make little sense. They cannot reliably follow verbal commands.
Oliver Hart
Dominant inferior-division MCA. Wernicke-pattern aphasia.
Claire Brooks
What's the trap?
Oliver Hart
Assuming intact speech output equals intact cognition or communication.
Oliver Hart
### CASE 3 - NONDOMINANT MCA
Claire Brooks
Next. Right hemispheric stroke. Patient has left weakness.
Claire Brooks
During wheelchair mobility, they clip every doorway on the left. They eat only the food on the right half of the tray.
Claire Brooks
When asked why the left arm isn't moving, they say: "My arm is fine."
Oliver Hart
Severe left neglect with anosognosia from a nondominant hemispheric stroke.
Claire Brooks
Functional danger?
Oliver Hart
Massive. Falls. Collisions. Poor carryover of precautions. Failure to protect the paretic limb. Difficulty learning compensatory strategies because the patient doesn't recognize the deficit.
Oliver Hart
### CASE 4 - PCA
Claire Brooks
Patient can write a sentence. Then I ask them to read what they just wrote. They can't.
Oliver Hart
Alexia without agraphia. Think dominant left PCA territory involving left visual cortex and posterior callosal pathways.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 16
Oliver Hart
### CASE 5 - LACUNAR
Claire Brooks
Face, arm, and leg are weak on the right. No aphasia. No neglect. No field cut. No major sensory deficit.
Oliver Hart
Pure motor lacunar syndrome. Think posterior limb of internal capsule, cerebral peduncle, or pontine base.
Oliver Hart
### CASE 6 - BRAINSTEM
Claire Brooks
Left facial pain-temperature loss. Right body pain-temperature loss. Vertigo. Hoarse voice. Dysphagia. Left Horner syndrome.
Oliver Hart
Left lateral medullary - Wallenberg syndrome.
Claire Brooks
That one should be automatic.
Oliver Hart
Absolutely.
Oliver Hart
### CASE 7 - LOCKED-IN
Claire Brooks
Patient appears quadriplegic. Cannot speak. Cannot voluntarily move the face. Does not respond with limb movement. But follows commands with vertical eye movement.
Oliver Hart
Think locked-in syndrome from bilateral ventral pontine injury. And assume awareness until proven otherwise.
Oliver Hart
### MASTER RAPID-FIRE ROUND
Claire Brooks
Twenty-five. Short answers. Ready?
Oliver Hart
Go.
Claire Brooks
ACA stroke: leg or arm more affected?
Oliver Hart
Leg.
Claire Brooks
Superior MCA: arm or leg more affected?
Oliver Hart
Arm and hand.
Claire Brooks
Broca aphasia: fluent or nonfluent?
Oliver Hart
Nonfluent.
Claire Brooks
Wernicke aphasia?
Oliver Hart
Fluent with poor comprehension.
Claire Brooks
Global aphasia usually requires?
Oliver Hart
Large dominant-hemisphere language-network injury, such as a major MCA stroke.
Claire Brooks
Right parietal stroke classic deficit?
Oliver Hart
Left hemispatial neglect.
Claire Brooks
Visual-field deficit from one occipital lobe?
Oliver Hart
Contralateral homonymous hemianopsia.
Claire Brooks
Internal capsule lesion?
Oliver Hart
Dense contralateral motor deficit is common.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 17
Claire Brooks
Thalamic lacune?
Oliver Hart
Pure sensory stroke.
Claire Brooks
Posterior limb lacune?
Oliver Hart
Pure motor hemiparesis.
Claire Brooks
PCA cortical syndrome?
Oliver Hart
Visual-field loss.
Claire Brooks
Left PCA plus posterior callosal involvement?
Oliver Hart
Alexia without agraphia.
Claire Brooks
Bilateral occipital injury with denial of blindness?
Oliver Hart
Anton syndrome.
Claire Brooks
Frontal eye-field destructive lesion - eyes point?
Oliver Hart
Toward the hemispheric lesion.
Claire Brooks
Brainstem localization hallmark?
Oliver Hart
Ipsilateral cranial nerve findings with contralateral body findings.
Claire Brooks
MLF lesion?
Oliver Hart
Internuclear ophthalmoplegia.
Claire Brooks
Weber syndrome?
Oliver Hart
Ipsilateral CN III palsy plus contralateral weakness.
Claire Brooks
Wallenberg - facial pain-temperature deficit?
Oliver Hart
Ipsilateral.
Claire Brooks
Body pain-temperature deficit?
Oliver Hart
Contralateral.
Claire Brooks
Wallenberg - Horner?
Oliver Hart
Ipsilateral.
Claire Brooks
Wallenberg - major bulbar problem?
Oliver Hart
Dysphagia and dysphonia.
Claire Brooks
Locked-in awareness?
Oliver Hart
Preserved.
Claire Brooks
Locked-in eye movement often preserved?
Oliver Hart
Vertical.
Claire Brooks
Classic cerebellar stroke symptoms?
Oliver Hart
Vertigo, headache, emesis, gait ataxia.
Claire Brooks
And the single most important stroke question for rehab after localization?
Oliver Hart
What does this lesion predict about function?
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 18
Oliver Hart
### SEGMENT 37 - AVOID THE "HEMIPARESIS = STROKE SEVERITY" TRAP
Claire Brooks
I want to end on something important for rehab. If I compare two patients purely by strength, I can completely misjudge their rehabilitation complexity.
Oliver Hart
Absolutely.
Oliver Hart
Consider patient A with dense pure motor hemiparesis from an internal-capsule lacune.
Oliver Hart
Patient B has only mild weakness after a right parietal stroke but severe neglect and anosognosia.
Oliver Hart
Patient A may look worse on manual muscle testing. Patient B may be much more dangerous during unsupervised mobility.
Claire Brooks
Or a Wernicke patient with full strength who can't understand safety instructions.
Oliver Hart
Exactly. Or a cerebellar patient with near-normal strength who cannot stand without losing balance.
Oliver Hart
Or a locked-in patient whose motor exam looks catastrophic while cognition remains preserved.
Oliver Hart
Neurologic impairment must be interpreted through function.
Oliver Hart
### SEGMENT 38 - THE STROKE LOCALIZATION ALGORITHM
Claire Brooks
Give me something I can mentally run through on rounds.
Oliver Hart
Seven questions.
Oliver Hart
One: Is this cortical, subcortical, brainstem, or cerebellar? Cortical signs include things like aphasia, neglect, apraxia, and cortical visual or sensory findings.
Oliver Hart
Two: Is weakness face/arm predominant, leg predominant, or equally dense? That helps distinguish lateral cortex, medial cortex, and compact subcortical tracts.
Oliver Hart
Three: Is there a language syndrome? If yes, think dominant hemisphere.
Oliver Hart
Four: Is there neglect or severe spatial dysfunction? Think nondominant hemisphere, especially posterior parietal networks.
Oliver Hart
Five: Are visual fields involved? Think optic pathways, radiations, occipital cortex, PCA or MCA depending on anatomy.
Oliver Hart
Six: Are cranial nerve and body findings crossed? Think brainstem.
Oliver Hart
Seven: What functional consequences should I actively test? Communication. Swallowing. Vision. Attention. Awareness. Apraxia. Mobility. Balance. ADLs. Safety.
Claire Brooks
That last question is the PM&R part.
Oliver Hart
That's the whole point.
Oliver Hart
### FINAL HIGH-YIELD SUMMARY
Claire Brooks
Three takeaways. If everything else disappears by morning, what stays?
Oliver Hart
Takeaway One: Vascular anatomy predicts the impairment pattern.
Oliver Hart
ACA - think medial frontal structures and leg-predominant deficits.
Oliver Hart
BEYOND THE DIAGNOSIS | EPISODE 3
Oliver Hart
Stroke Syndromes - Podcast Script | 19
Oliver Hart
MCA - think lateral hemisphere: face and arm motor function, language in the dominant hemisphere, spatial attention in the nondominant hemisphere.
Oliver Hart
PCA - think visual cortex, thalamic sensory syndromes, and characteristic disconnection phenomena.
Oliver Hart
Deep perforator disease - think compact lacunar syndromes.
Claire Brooks
Number two?
Oliver Hart
Takeaway Two: Cortical signs and brainstem signs tell you where to look.
Oliver Hart
Aphasia, neglect, apraxia, and complex visuospatial dysfunction push you toward cortex.
Oliver Hart
Dense pure motor or sensory syndromes can suggest subcortical disease.
Oliver Hart
Crossed cranial-nerve and body findings point toward brainstem.
Oliver Hart
Vertigo plus gait or limb ataxia should keep posterior circulation and cerebellum in your differential.
Claire Brooks
And number three?
Oliver Hart
Takeaway Three: Stroke severity is not synonymous with weakness severity.
Oliver Hart
A patient with mild weakness and severe neglect may be less safe than a patient with dense pure motor hemiparesis.
Oliver Hart
A patient who speaks fluently may have profound receptive aphasia.
Oliver Hart
A patient who cannot move may still be fully conscious.
Oliver Hart
And a patient with normal strength may be unable to walk because coordination has failed.
Oliver Hart
The rehabilitation question is always: What did this lesion do to the person's ability to function?
Claire Brooks
Localize the lesion.
Oliver Hart
Predict the syndrome.
Claire Brooks
Predict the function.
Oliver Hart
Then build the rehabilitation plan around the patient in front of you.
Claire Brooks
That's Stroke Syndromes.
Oliver Hart
And yes - you actually do have to know your neuroanatomy.
Claire Brooks
I was hoping you weren't going to say that.
Oliver Hart
You uploaded an eighteen-page stroke localization chapter.
Claire Brooks
Fair.
Claire Brooks
### OPTIONAL POST-ROLL - 3-MINUTE ACTIVE-RECALL DRILL
Claire Brooks
Last round. Answer before Host B.
Claire Brooks
A left ACA stroke most strongly affects which limb?
Oliver Hart
The contralateral right lower limb.
Claire Brooks
A dominant superior-division MCA stroke commonly produces what aphasia?
Claire Brooks
BEYOND THE DIAGNOSIS | EPISODE 3
Claire Brooks
Stroke Syndromes - Podcast Script | 20
Oliver Hart
Broca aphasia.
Claire Brooks
Dominant inferior-division MCA?
Oliver Hart
Wernicke aphasia.
Claire Brooks
Large dominant MCA?
Oliver Hart
Potential global aphasia.
Claire Brooks
Nondominant parietal lesion?
Oliver Hart
Contralateral hemispatial neglect - classically left neglect from a right hemispheric lesion.
Claire Brooks
Right occipital lesion?
Oliver Hart
Left homonymous hemianopsia.
Claire Brooks
Pure face-arm-leg weakness with no cortical signs?
Oliver Hart
Pure motor lacunar syndrome.
Claire Brooks
Pure unilateral face-arm-leg sensory loss?
Oliver Hart
Pure sensory lacunar syndrome, classically thalamic.
Claire Brooks
Cannot read but can write?
Oliver Hart
Alexia without agraphia.
Claire Brooks
Ipsilateral third-nerve palsy plus contralateral weakness?
Oliver Hart
A midbrain syndrome - classically Weber.
Claire Brooks
Ipsilateral face pain-temperature loss plus contralateral body pain-temperature loss?
Oliver Hart
Lateral brainstem pattern; if accompanied by dysphagia, vertigo, ataxia, and Horner syndrome, think Wallenberg.
Claire Brooks
Quadriplegic and mute but awake with preserved vertical eye movements?
Oliver Hart
Locked-in syndrome.
Claire Brooks
Vertigo, headache, vomiting, severe gait ataxia?
Oliver Hart
Cerebellar stroke should be considered.
Claire Brooks
And finally: Why does a physiatrist care about stroke syndromes when the MRI has already told us where the lesion is?
Claire Brooks
BEYOND THE DIAGNOSIS | EPISODE 3
Claire Brooks
Stroke Syndromes - Podcast Script | 21
Oliver Hart
Because lesion location lets us predict the motor, sensory, cognitive, communication, visual, perceptual, swallowing, balance, and safety problems that will determine rehabilitation.
Oliver Hart
Host A should sound curious, animated, and slightly faster. Host B should sound calm, clinically authoritative, and conversational rather than lecture-like. Preserve the pause cues in the active-recall section so the finished audio functions as retrieval practice, not passive listening.
Oliver Hart
Source basis: Chapter 44, Stroke Syndromes. The script is organized around the chapter's progression from cortical and subcortical neuroanatomy to cerebrovascular territories, lacunar syndromes, infratentorial anatomy, brainstem syndromes, cerebellar patterns, and rehabilitation consequences.