01Approach to the Critical Patient/attcp59

Immediate stabilization

›Airway and breathing assessment

›Secure airway if GCS depressed or bulbar dysfunction present

›Rapid sequence intubation for GCS < 8 or inability to protect airway

›Aspiration precautions during intubation for pontine infarction

›Oxygenation targets

›SpO2 >= 94% in acute ischemic stroke

›Supplemental oxygen only if SpO2 < 94%

›Respiratory pattern monitoring

›Cheyne-Stokes pattern indicates bilateral hemispheric or pontine involvement

›Apneusis or ataxic breathing signals extensive pontine injury

›Vascular access and hemodynamic targets

›Two large-bore IV lines

›IV fluid only for hemodynamic compromise or NPO maintenance

›Avoid aggressive hydration

›Blood pressure targets per stroke phase

›Pre-thrombolysis: SBP < 185 mmHg and DBP < 110 mmHg required

›Post-thrombolysis: maintain SBP < 180 mmHg and DBP < 105 mmHg for 24 hours

›If thrombolysis not given: permissive hypertension; intervene only if SBP > 220 mmHg or DBP > 120 mmHg

›Cardiac monitoring

›Continuous telemetry for atrial fibrillation detection

›12-lead ECG for neurogenic ST changes and arrhythmia

Time-critical decision branch

›Thrombolysis eligibility window

›IV alteplase if onset-to-treatment within 4.5 hours and no contraindications

›Dose 0.9 mg/kg; max 90 mg; 10% as bolus over 1 minute then remainder over 60 minutes

›Class I recommendation, Level A evidence

›CT head required before alteplase to exclude hemorrhage

02History/hx82

Symptom onset and presentation

›Core triad components

›Ipsilateral horizontal gaze palsy or diplopia

›Sudden onset inability to look toward side of lesion

›Esotropia at rest from abducens involvement

›Ipsilateral peripheral facial palsy

›Both upper and lower face involved (no forehead sparing)

›Differentiates from central (supranuclear) facial palsy

›Contralateral limb weakness or hemiplegia

›Arm and leg involvement

›May include contralateral hemisensory loss

›Onset characterization

›Sudden onset over seconds to minutes suggests vascular etiology

›Ischemic stroke most common

›Hemorrhagic stroke onset may be slightly more gradual

›Subacute onset over hours to days

›Demyelinating disease (MS) consideration

›Pontine tumor or abscess

›Last known well time

›Critical for thrombolysis eligibility window

›Witness account of exact onset

Associated symptoms

›Posterior circulation features

›Vertigo and nausea

›Vestibular nuclear involvement in lower pons

›May mimic peripheral vertigo early

›Dysarthria

›Corticobulbar tract involvement

03Physical Exam/exam73

Vital signs and general

›Hemodynamic snapshot

›Blood pressure (both arms)

›Significant asymmetry suggests subclavian stenosis or dissection

›Hypertension extremely common in acute pontine infarction

›Heart rate and rhythm

›Irregular pulse for atrial fibrillation

›Bradycardia with respiratory pattern changes in severe pontine lesions

›Temperature

›Fever suggesting infectious etiology (abscess, encephalitis)

›Hyperthermia post-stroke indicates larger infarct volume and worse outcome

›Respiratory rate and pattern

›Cheyne-Stokes, apneustic, or ataxic patterns localize brainstem injury

Cranial nerve examination

›Ocular motor findings (hallmark of Foville's syndrome)

›Ipsilateral conjugate gaze palsy

›Eyes cannot look toward the side of the lesion

›Caused by abducens nucleus and PPRF involvement

›Eyes deviate toward the side of hemiplegia (away from lesion)

›Ipsilateral abducens palsy with esotropia

›Cannot abduct ipsilateral eye

›Distinguishes from one-and-a-half syndrome (preserved contralateral abduction)

›Internuclear ophthalmoplegia assessment

›Medial longitudinal fasciculus involvement

›Adduction lag on saccades

›Nystagmus pattern

›Horizontal gaze-evoked nystagmus

›Direction-changing nystagmus suggests vestibular nucleus involvement

›Facial nerve assessment

›Ipsilateral peripheral facial palsy

›Both upper and lower face equally affected

›Forehead wrinkle loss ipsilateral (unlike central palsy)

›Lagophthalmos: incomplete eye closure

›Corneal reflex

›Diminished or absent ipsilateral corneal reflex

›CN V afferent and CN VII efferent pathway test

›Jaw deviation

›CN V motor if lesion extends to trigeminal nucleus

›Other cranial nerves

›CN VIII: ipsilateral hearing loss if caudal pontine involvement

›Weber and Rinne tests at bedside

›Gag reflex and palatal movement

›CN IX/X involvement indicates more extensive lesion

›High aspiration risk if absent

Motor and sensory examination

›Contralateral motor deficit

›Hemiplegia or hemiparesis contralateral to lesion

›Corticospinal tract involvement in pontine base

›Upper motor neuron pattern: hyperreflexia, upgoing plantar response

›Pronator drift

›Subtle arm weakness detection

›Grip strength comparison

›Bilateral comparison

›Sensory examination

›Contralateral hemisensory loss

›Medial lemniscus involvement: fine touch and proprioception

›Spinothalamic involvement: pain and temperature

›Facial sensation

›Ipsilateral facial numbness if descending trigeminal tract involved

›Cerebellar and coordination

›Ipsilateral ataxia

›Middle cerebellar peduncle involvement

›Finger-nose-finger and heel-shin tests

›Gait assessment when safe

›Wide-based ataxic gait

›Romberg test

PITFALLS

›Exam interpretation pitfalls

›Forehead sparing misinterpretation

›Peripheral facial palsy (CN VII nucleus/fascicle) involves forehead

›Central (supranuclear) facial palsy spares forehead — do not confuse the two

›NIHSS underestimates posterior circulation stroke severity

›Horizontal gaze palsy, ataxia, and cranial nerve deficits scored poorly

›Clinical exam more informative than NIHSS score alone

›Pure Foville triad uncommon in practice

›Most pontine infarctions present with incomplete or overlapping features

›Partial syndromes still localize to pons

04Differential Diagnosis/ddx56

Brainstem syndromes and close mimics

›Classic alternating brainstem syndromes

›Millard-Gubler syndrome

›ICD-10 G46.3 (brainstem stroke syndrome)

›Ipsilateral CN VI and CN VII palsy with contralateral hemiplegia

›Lesion involves CN VI fascicle (not nucleus/PPRF) — no conjugate gaze palsy

›One-and-a-half syndrome

›Ipsilateral gaze palsy plus ipsilateral internuclear ophthalmoplegia

›No facial palsy or hemiplegia

›Eight-and-a-half syndrome

›One-and-a-half syndrome plus ipsilateral peripheral facial palsy

›More extensive tegmental lesion than Foville's

›Locked-in syndrome

›Bilateral ventral pontine lesion

›Quadriplegia and anarthria with intact vertical eye movements and consciousness

›Posterior circulation vascular emergencies

›Pontine hemorrhage

›ICD-10 I61.3

›Pinpoint pupils, rapid deterioration, hyperdensity on non-contrast CT

›Immediate neurosurgical evaluation

›Basilar artery occlusion

›ICD-10 I63.22

›More extensive deficits, often bilateral, decreased consciousness

›Mortality exceeds 80% without recanalization

›Vertebral artery dissection

›ICD-10 I77.74

›Younger patient, neck pain, recent trauma or manipulation

›MRA or CTA shows intimal flap or double lumen

05Laboratory Tests/lt46

Acute stroke workup

›Stat labs required before thrombolysis

›Blood glucose (point of care)

›Hypoglycemia mimics stroke; glucose < 2.8 mmol/l must be excluded before alteplase

›Target glucose 7.8 to 10 mmol/l in acute stroke

›Complete blood count

›Platelet count < 100 x 10^9/L is alteplase contraindication

›Leukocytosis suggesting infectious etiology

›Coagulation studies

›INR > 1.7 is relative contraindication to thrombolysis

›aPTT > 40 seconds or direct anticoagulant on board

›Renal function and electrolytes

›Creatinine for contrast use and medication dosing

›Sodium correction rate if hyponatremia is contributing factor

Cardiac and embolic source evaluation

›Cardiac biomarkers

›High-sensitivity troponin

›Neurogenic myocardial injury in large strokes

›Concurrent ACS must be excluded

›12-lead ECG and continuous telemetry

›Atrial fibrillation detection — most common cardioembolic source

›QTc prolongation monitoring (relevant to antiarrhythmic therapy)

›BNP or NT-proBNP

›Heart failure with reduced ejection fraction as embolic substrate

›Lipid and metabolic risk factor labs

›Fasting lipid panel

›LDL target < 1.8 mmol/l for secondary prevention in atherosclerotic stroke

›HbA1c

06Diagnostic Tests/dt109

Scoring Systems

›NIHSS (National Institutes of Health Stroke Scale)

›Stroke severity quantification at presentation

›Score 0-42; higher scores correlate with worse prognosis

›Posterior circulation strokes significantly underscored by NIHSS

›Cranial nerve palsies, ataxia, and gaze palsy poorly captured

›Serial NIHSS monitoring

›Change of >= 4 points indicates significant deterioration or improvement

›Thrombolysis eligibility does not require minimum NIHSS threshold

›HINTS Exam (Head Impulse, Nystagmus, Test of Skew)

›Used when acute vestibular syndrome is the presenting feature

›Normal head impulse test (no catch-up saccade) — strongly suggests central cause

›Direction-changing nystagmus — central pattern

›Skew deviation present — central pattern

›HINTS plus (with hearing assessment) improves sensitivity for posterior fossa stroke

›Sensitivity > 99% for posterior circulation stroke when performed by trained examiner

›More sensitive than MRI DWI in first 48 hours for posterior stroke

›PC-ASPECTS (Posterior Circulation Alberta Stroke Program Early CT Score)

›CT-based scoring for posterior circulation ischemia extent

›Score range 0-10; score < 8 associated with worse outcomes

›Applied to basilar artery territory infarction assessment

›Guides thrombectomy candidate selection

›ABCD2 Score (for TIA risk stratification)

›Age >= 60 years (1 point), BP >= 140/90 mmHg (1 point)

›Clinical features: unilateral weakness (2), speech disturbance (1)

›Duration: >= 60 min (2), 10-59 min (1)

›Diabetes (1)

›Score >= 4 indicates high 2-day stroke risk

›Immediate evaluation and admission warranted

MRI

›MRI brain with DWI (gold standard for pontine infarction)

›Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC)

›Hyperintense on DWI with ADC restriction confirms acute infarction

›Detects infarcts within 30 minutes of onset in most supratentorial cases

›Falsely negative in up to 41% of dorsolateral pontine infarctions within 48 hours

›Infarct localization on MRI

›Foville's syndrome: caudal pontine tegmentum and base

›Facial colliculus involvement at floor of fourth ventricle

›Bilateral involvement predicts locked-in state risk

›FLAIR (Fluid-attenuated inversion recovery)

›Less sensitive than DWI acutely but useful for chronic changes

›Periventricular white matter changes — leukoaraiosis as vascular risk marker

›Gradient echo / susceptibility-weighted imaging (SWI)

›Blooming artifact distinguishes hemorrhagic from ischemic lesion

›Hemosiderin deposits in cavernous malformation

›Microbleeds indicate small vessel disease burden

›MR Angiography (MRA)

›Vertebrobasilar vasculature assessment

›Vertebral artery stenosis, occlusion, or dissection

›Basilar artery stenosis or thrombosis

›Time-of-flight MRA: non-contrast but less sensitive for slow flow

›Contrast-enhanced MRA

›Better delineation of posterior fossa vasculature

›Gadolinium enhancement of vessel wall in dissection or vasculitis

›MRI spine if cord involvement suspected

›Cervical myelopathy exclusion

›Rule out foramen magnum lesion mimicking brainstem syndrome

›MS plaques in spinal cord

›Dissemination in space criterion for MS diagnosis

CT

›Non-contrast CT head (first-line emergency imaging)

›Mandatory before thrombolysis to exclude hemorrhage

›Hyperdensity in posterior fossa indicates hemorrhage

›Pontine hemorrhage: hyperdense focus with surrounding edema

›Limitations in posterior fossa

›Beam hardening artifact reduces sensitivity for ischemia

›Sensitivity for posterior circulation ischemia < 50% within 24 hours

›Normal CT does not exclude Foville's syndrome from infarction

›CT Angiography (CTA) of head and neck

›Basilar artery occlusion identification

›Dense basilar artery sign on non-contrast CT

›CTA confirms occlusion site and extent

›Required urgently in all suspected posterior circulation strokes

›Vertebral artery assessment

›Dissection: intimal flap, double lumen, intramural hematoma

›Stenosis: degree and location for intervention planning

›Collateral assessment

›Posterior communicating artery patency

›Basilar artery collateral flow sources

›CT Perfusion (CTP)

›Ischemic penumbra quantification

›Mismatch between core infarct and penumbra guides late-window thrombectomy

›Less validated in posterior fossa than anterior circulation

›RAPID software or equivalent automated processing

›Core > 70 mL may not benefit from thrombectomy

›Mismatch ratio > 1.8 favors intervention

Ultrasound

›Carotid and vertebral duplex ultrasound

›Vertebral artery flow assessment

›Subclavian steal syndrome: reversed vertebral flow

›Vertebral artery stenosis or hypoplasia

›Carotid intima-media thickness

›Atherosclerotic burden assessment

›Plaque characterization (echogenicity, ulceration)

›Echocardiography

›Transthoracic echocardiography (TTE)

›Left ventricular thrombus: apical wall motion abnormality

›Valvular disease: vegetation (endocarditis), rheumatic disease

›Ejection fraction assessment for cardioembolism risk

›Transesophageal echocardiography (TEE)

›Patent foramen ovale detection with bubble study

›Atrial septal aneurysm

›Left atrial appendage thrombus: superior to TTE for detection

›Bubble study (agitated saline contrast)

›PFO detection with Valsalva maneuver

›Significant right-to-left shunting indicates paradoxical embolism risk

›Transcranial Doppler (TCD)

›Basilar artery flow velocity monitoring

›Vasospasm after subarachnoid hemorrhage

›Recanalization monitoring after thrombolysis

›Microemboli detection

›High-intensity transient signals indicate active embolism

›Guides antithrombotic therapy intensity

07Disposition/dispo39

Admission criteria

›Hospital admission required for all acute Foville's syndrome

›No safe outpatient pathway for acute brainstem stroke

›Rapid deterioration risk: basilar artery thrombosis propagation

›Thrombolysis and monitoring window requirements

›Stroke unit admission (minimum)

›Continuous cardiac and neurological monitoring

›Access to stroke team and rehabilitation services

ICU and high-dependency criteria

›Neuro-ICU indications

›Basilar artery occlusion confirmed or suspected

›Aggressive monitoring for locked-in state progression

›Endovascular therapy monitoring post-procedure

›Fluctuating or progressive neurological deficits

›Serial NIHSS every 1 to 2 hours

›Repeat CT or MRI if significant change

›Decreased level of consciousness

›GCS < 13 or NIHSS > 15 in posterior circulation stroke

›Respiratory compromise

›Bulbar dysfunction with aspiration risk

›Mechanical ventilation in place

Transfer criteria

›Transfer to comprehensive stroke center

›Endovascular thrombectomy capability required for basilar occlusion

›Do not delay alteplase for transfer — treat if eligible before transfer

›Door-to-puncture time target < 120 minutes at receiving center

›No neurology or neurosurgery on site

›Pontine hemorrhage requiring surgical evaluation

08Treatment/t88

Acute reperfusion therapy

›IV alteplase (tPA) for acute ischemic stroke

›Dose and administration

›0.9 mg/kg intravenously; maximum dose 90 mg

›10% of dose given as IV bolus over 1 minute

›Remaining 90% infused over 60 minutes

›Eligibility window

›Within 4.5 hours of symptom onset (last known well)

›Class I recommendation, Level A evidence

›Key absolute contraindications

›Intracranial hemorrhage on CT

›BP > 185/110 mmHg despite treatment

›INR > 1.7, aPTT > 40 seconds

›Platelet count < 100 x 10^9/L

›Direct oral anticoagulant within 48 hours

›Post-thrombolysis monitoring

›BP < 180/105 mmHg for 24 hours after infusion

›Neurological checks every 15 minutes during infusion

›No antiplatelet or anticoagulation for 24 hours after alteplase

Blood pressure management

›Pre-thrombolysis BP control

›Target SBP < 185 mmHg and DBP < 110 mmHg before alteplase

›Labetalol 10 to 20 mg IV over 1 to 2 minutes

›May repeat every 10 minutes; maximum 300 mg

›Nicardipine infusion 5 mg/hour IV

›Titrate by 2.5 mg/hour every 5 to 15 minutes

›Maximum 15 mg/hour

›Post-thrombolysis BP target

›SBP < 180 mmHg and DBP < 105 mmHg for 24 hours

›More stringent to reduce hemorrhagic transformation risk

›Continuous arterial line preferred for accurate monitoring

›No thrombolysis — permissive hypertension

›Intervene only if SBP > 220 mmHg or DBP > 120 mmHg

›Avoid aggressive reduction in first 24 hours

›Exception: aortic dissection, hypertensive encephalopathy, ACS concurrent

Antiplatelet therapy

›Aspirin for acute ischemic stroke (when thrombolysis not given)

›Aspirin 325 mg orally (or PR if dysphagia) within 24 to 48 hours

›Class I recommendation, Level A evidence

›Do not give within 24 hours of alteplase

›Dual antiplatelet therapy for minor stroke or TIA

›Aspirin 100 mg plus clopidogrel 75 mg daily for 21 days

›Clopidogrel loading dose 300 mg on day 1

›Based on POINT and CHANCE trials

›Reduces early recurrence risk compared to aspirin alone

›Transition to monotherapy after 21 days for long-term secondary prevention

Anticoagulation

›Cardioembolic source (atrial fibrillation)

›Direct oral anticoagulants (DOACs) preferred over warfarin

›Apixaban 5 mg orally twice daily (reduce to 2.5 mg if >= 2 of: age >= 80, weight <= 60 kg, creatinine >= 133 umol/l)

›Rivaroxaban 20 mg orally daily with evening meal

›Dabigatran 150 mg orally twice daily (110 mg if age >= 80 or high bleeding risk)

›Timing of anticoagulation initiation post-stroke

›TIA: immediate anticoagulation

›Minor stroke: 3 to 5 days post-event

›Moderate stroke: 6 to 10 days post-event

›Severe stroke: 12 to 14 days post-event

›Vertebral artery dissection

›Antiplatelet or anticoagulation both acceptable

›No superiority demonstrated between strategies (CADISS trial)

›Anticoagulation duration 3 to 6 months then reassess imaging

Statin therapy

›High-intensity statin for atherosclerotic stroke

›Atorvastatin 40 to 80 mg orally daily

›Start within 48 hours of ischemic stroke onset

›LDL target < 1.8 mmol/l for secondary prevention

›Rosuvastatin 20 to 40 mg orally daily as alternative

›SPARCL trial: 16% relative risk reduction in recurrent stroke with high-dose statin

›Continue indefinitely unless contraindicated

Neuroprotective and supportive measures

›Glycemic management

›Target blood glucose 7.8 to 10 mmol/l in acute stroke

›Hypoglycemia (< 3.3 mmol/l) worsens outcome and must be corrected immediately

›Hyperglycemia (> 10 mmol/l) associated with larger infarct expansion

›Insulin infusion if persistent hyperglycemia

›Avoid hypoglycemia during treatment

›Temperature management

›Treat fever aggressively

›Paracetamol 1 g every 6 hours for temperature > 37.5 degrees C

›Fever worsens ischemic injury

›Targeted temperature management not routinely recommended

›Evidence insufficient outside clinical trials

›DVT prophylaxis

›Intermittent pneumatic compression from day 1

›Class I recommendation in immobile stroke patients

›Pharmacological prophylaxis

›Enoxaparin 40 mg subcutaneously daily when safe (after 24 hours if alteplase given)

Dysphagia and aspiration prevention

›Swallowing assessment protocol

›NPO until formal swallowing evaluation

›Bedside water swallow test as initial screen

›Formal videofluoroscopic swallow study if bedside screen fails

›Nasogastric tube feeding if dysphagia severe

›Initiate early enteral nutrition within 24 hours

›PEG consideration if dysphagia persists beyond 2 to 4 weeks

09Special Populations/sp74

Pregnancy

›Pregnancy-specific stroke considerations

›Epidemiology and risk

›Pregnancy increases stroke risk approximately 3-fold

›Highest risk in third trimester and peripartum period

›Preeclampsia and eclampsia as additional etiologies

›Etiology differences in pregnancy

›Cerebral venous sinus thrombosis more common in postpartum period

›Cardioembolism from peripartum cardiomyopathy

›Paradoxical embolism via PFO increased with Valsalva during labor

›Treatment modifications in pregnancy

›IV alteplase — use with caution, not absolutely contraindicated

›Risk-benefit discussion with obstetrics and neurology

›Placental abruption and hemorrhage are concerns

›Major stroke with high maternal risk may favor use

›Anticoagulation

›Unfractionated heparin or LMWH preferred over warfarin (teratogenic)

›DOACs contraindicated in pregnancy

›Enoxaparin 1 mg/kg subcutaneously twice daily for acute DVT/PE in pregnancy

›Antihypertensive agents

›Labetalol and hydralazine safe in pregnancy for acute BP control

›ACE inhibitors and ARBs contraindicated

›Methyldopa for chronic management in pregnancy

›Statins contraindicated in pregnancy

›Discontinue on diagnosis of pregnancy

›Resume postpartum

Geriatric

›Age-related considerations

›Prevalence and outcome

›Pontine infarction incidence increases with age

›Higher rates of hypertension, atrial fibrillation, and small vessel disease

›Mortality higher in elderly: functional outcome inversely related to age

›Atypical presentations in elderly

›Delirium may be the dominant feature masking focal deficits

›Falls with occult pontine stroke

›Lower fever response to infectious mimics

›Treatment modifications in elderly

›Alteplase remains beneficial in patients >= 80 years

›Age alone is not a contraindication

›Increased hemorrhagic transformation risk; weigh carefully

›Anticoagulation considerations

›DOAC dosing adjustment for renal function decline

›Apixaban 2.5 mg twice daily if >= 2 criteria: age >= 80, weight <= 60 kg, creatinine >= 133 umol/l

›Fall risk assessment before anticoagulation — still recommended if AF present

›Antihypertensive caution

›Orthostatic hypotension risk with aggressive BP reduction

›Syncope and fall cascade

›Rehabilitation

›Early mobilization reduces complications even in frail elderly

›Physiotherapy, occupational therapy, and speech pathology essential

›Sarcopenia and deconditioning accelerate with bed rest

Pediatrics

›Pediatric posterior circulation stroke

›Epidemiology

›Arterial ischemic stroke incidence: 2 to 8 per 100,000 children per year

›Posterior circulation strokes account for approximately 20% of pediatric arterial ischemic stroke

›Brainstem strokes rare but carry high morbidity

›Etiologies different from adults

›Cardiac disease (congenital heart disease) most common in neonates and infants

›Sickle cell disease

›Arteriopathies: moyamoya, focal cerebral arteriopathy, dissection

›Infections: varicella-related arteriopathy, meningitis

›Prothrombotic states

›Treatment in pediatric patients

›Alteplase in children

›Not FDA-approved under age 18; use off-label with neurology guidance

›Case series support use in severe pediatric stroke

›Dose same weight-based calculation: 0.9 mg/kg; max 90 mg

›Antiplatelet therapy

›Aspirin 3 to 5 mg/kg/day (max 100 mg/day) for non-cardioembolic stroke

›Reye syndrome risk: avoid aspirin if influenza or varicella suspected

›Anticoagulation in children

›Enoxaparin 1 mg/kg subcutaneously twice daily (< 2 months: 1.5 mg/kg twice daily)

›Anti-Xa level target 0.5 to 1.0 units/mL

›Rehabilitation

›Neuroplasticity advantage in children; prognosis often better than adults

›Early intensive rehabilitation recommended

10Background/b83

Epidemiology

›Incidence and prevalence

›Foville's syndrome is rare; no large epidemiological series exist

›Pontine infarction accounts for 7 to 10% of all ischemic strokes

›Classic complete Foville's triad uncommon; most present with partial syndromes

›Isolated pontine infarct demographics

›Mean age of presentation in 6th to 7th decade

›Male predominance in most series

›Small artery disease (lacunar) most common mechanism in pontine infarction

›Etiology distribution

›Small artery disease (perforator occlusion): 40 to 50% of pontine infarcts

›Hypertension and diabetes most important risk factors

›5-year recurrence rate approximately 29% in small artery disease

›Basilar branch disease: 20 to 30%

›Lowest recurrence rate approximately 2% at 5 years

›Large artery atherosclerosis (basilar stenosis): 15 to 20%

›5-year recurrence approximately 14%

›Cardioembolic: 10 to 15%

›Atrial fibrillation dominant source

›Vertebral or basilar dissection: 5 to 10% especially younger patients

›Prognosis

›Functional recovery good in approximately two-thirds of isolated pontine infarcts

›Facial palsy and gaze palsy recover faster than hemiparesis

›Lower pontine and large ventral infarcts carry worse prognosis

›Mortality in basilar artery occlusion without recanalization: > 80%

›Recanalization improves survival to approximately 40 to 50%

Pathophysiology

›Anatomy of the caudal pontine tegmentum

›Abducens nucleus and PPRF (paramedian pontine reticular formation)

›Abducens nucleus contains motoneurons for ipsilateral lateral rectus

›Also contains interneurons projecting via MLF to contralateral medial rectus

›PPRF is the horizontal gaze center — lesion causes ipsilateral gaze palsy

›Facial nerve fascicle at the facial colliculus

›CN VII axons loop around the abducens nucleus forming the internal genu

›Facial colliculus is the floor of the fourth ventricle landmark

›Lesion here causes ipsilateral peripheral (lower motor neuron) facial palsy

›Corticospinal tract (basis pontis)

›Descending motor fibers in the ventral pons

›Disruption causes contralateral hemiplegia (upper motor neuron)

›Creates the defining crossed (alternating) pattern

›Vascular supply of the caudal pons

›Short and long circumferential arteries from basilar artery

›Paramedian perforators supply medial pons

›Short circumferential arteries supply tegmentum

›Anterior inferior cerebellar artery (AICA)

›Supplies dorsolateral caudal pons including CN VII and VIII nuclei

›AICA territory infarction may include Foville's features

›Occlusion mechanisms

›Perforator occlusion from small vessel disease: lacunar mechanism

›Basilar artery branch occlusion: atherothrombotic or embolic

›Lesion localization

›Foville's syndrome requires lesion at caudal pontine tegmentum and base

›Pure tegmental lesion: gaze palsy + facial palsy without hemiplegia

›Tegmental + basilar lesion: complete triad with hemiplegia

›Differentiating from Millard-Gubler

›Millard-Gubler: CN VI fascicle (not nucleus) + corticospinal — no conjugate gaze palsy

›Foville's: CN VI nucleus/PPRF + CN VII fascicle + corticospinal — conjugate gaze palsy

Therapeutic Considerations

›Acute reperfusion evidence base

›IV alteplase evidence

›ECASS III trial: extended window to 4.5 hours (Class I, Level B)

›Benefit persists in posterior circulation strokes

›Earlier treatment associated with better outcomes (time is brain)

›Endovascular thrombectomy for basilar occlusion

›BASICS trial: endovascular therapy did not significantly improve outcomes vs best medical

›ATTENTION and BAOCHE trials: thrombectomy superior to medical therapy within 24 hours

›Current guidelines support thrombectomy for basilar occlusion within 24 hours

›Secondary prevention evidence

›Dual antiplatelet therapy

›POINT trial: aspirin + clopidogrel reduced recurrence 25% vs aspirin alone in minor stroke/TIA

›Duration limited to 21 days to balance bleeding risk

›CHANCE trial confirmed benefit in Chinese population

›Statin therapy

›SPARCL trial: atorvastatin 80 mg reduced stroke recurrence by 16% vs placebo

›High-intensity statin regardless of baseline LDL

›Blood pressure reduction

›SPS3 trial: intensive BP control (< 130 mmHg systolic) reduces recurrence in lacunar strokes

›ACE inhibitors and ARBs preferred agents for secondary prevention

›Rehabilitation evidence

›Early mobilization within 24 to 48 hours reduces complication rates

›A-VERY EARLY study: very early mobilization within 24 hours — caution in severe stroke

›Constraint-induced movement therapy for hemiparesis

›Evidence supports use in subacute and chronic phase

›Dysphagia rehabilitation

›Early SLP intervention reduces aspiration pneumonia risk

›Neuromuscular electrical stimulation for pharyngeal weakness

11Patient Discharge Instructions/pdi37

copy discharge instructions

›Discharge instructions for Foville's syndrome and posterior circulation stroke

›Understanding your diagnosis

›You have had a stroke affecting the brainstem (the base of the brain that controls eye movement, face muscles, and limb strength)

›The stroke caused weakness or paralysis of specific eye movements and facial muscles

›Recovery can continue for months with rehabilitation

›Medications — take exactly as prescribed

›Antiplatelet or anticoagulant medication to prevent another stroke

›Statin medication to lower cholesterol and reduce stroke risk

›Blood pressure medication to protect your blood vessels

›Do not stop any medication without talking to your doctor

›Activity and diet

›Follow swallowing precautions if recommended by your speech therapist

›Eat slowly and sit upright for at least 30 minutes after meals

›Low-sodium, heart-healthy diet to control blood pressure

›No smoking — smoking doubles stroke risk

›Avoid alcohol beyond 1 drink per day

›No driving until cleared by your neurologist (minimum 1 month)

›Eye and face care

›If your eye does not close completely, use lubricating eye drops during the day

›Use eye ointment at night and tape the eye closed if needed to prevent corneal damage

›Wear an eye patch for double vision if recommended

›Rehabilitation

›Attend all scheduled physical therapy, occupational therapy, and speech therapy appointments

›Perform home exercises as directed

›Rehabilitation can significantly improve strength, speech, and swallowing

›Follow-up appointments

›Neurology within 1 to 2 weeks of discharge

12References/r30

Guidelines and key sources

›Stroke management guidelines

›American Heart Association/American Stroke Association guidelines

›Powers WJ et al. Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update. Stroke. 2019; 50(12):e344-e418

›Class I Level A evidence for IV alteplase within 4.5 hours

›Mendelson SJ, Prabhakaran S. Diagnosis and Management of Transient Ischemic Attack and Acute Ischemic Stroke: A Review. JAMA. 2021; 325(11):1088-1098

›Comprehensive review of acute ischemic stroke management

›Markus HS, van der Worp HB, Rothwell PM. Posterior circulation ischaemic stroke and transient ischaemic attack: diagnosis, investigation, and secondary prevention. Lancet Neurology. 2013; 12(10):989-998

›Posterior circulation specific management recommendations

Foville's syndrome specific references

›Brainstem syndrome anatomy and case series

›Brogna C, Fiengo L, Ture U. Achille Louis Foville's Atlas of Brain Anatomy and the Defoville Syndrome. Neurosurgery. 2012

›Historical and anatomical review of Foville's syndrome

›Describes the classic triad and anatomical localization

›Kataoka S, Hori A, Shirakawa T, Hirose G. Paramedian Pontine Infarction. Neurological/Topographical Correlation. Stroke. 1997; 28(4):809-815

›MRI-clinical correlation in pontine infarction

›Kumral E, Bayulkem G, Evyapan D. Clinical Spectrum of Pontine Infarction. Clinical-MRI Correlations. Journal of Neurology. 2002; 249(12):1659-1670

›Describes clinical spectrum and imaging features

›Bassetti C, Bogousslavsky J, Barth A, Regli F. Isolated Infarcts of the Pons. Neurology. 1996; 46(1):165-175

›Isolated pontine infarcts: etiology, clinical features, and outcome

›Vemmos KN et al. Aetiopathogenesis and Long-Term Outcome of Isolated Pontine Infarcts. Journal of Neurology. 2005; 252(1):38-44

›Long-term recurrence rates by etiology (small artery, basilar branch, large artery)

Secondary prevention trials

›Key clinical trials informing treatment

›POINT Trial: Johnston SC et al. Clopidogrel and Aspirin in Acute Ischemic Stroke and High-Risk TIA. NEJM. 2018; 379(3):215-225

›21-day dual antiplatelet reduces recurrence by 25%

›SPARCL Trial: Amarenco P et al. High-Dose Atorvastatin after Stroke or TIA. NEJM. 2006; 355(6):549-559

›16% relative risk reduction in stroke recurrence with atorvastatin 80 mg

Evidence & Review