Brain Stem Vascular Syndromes

Midbrain (Fig. 15 a)

Syndrome

Structures involved

Manifestations

Weber's

• Ventral midbrain

• Ipsilateral CN III palsy, including

syndrome

• CN III corticospinal

parasympathetic paresis (i.e.,

track

dilated pupil)

• Contralateral hemiplegia

Benedikt's

• Midbrain tegmen-

• Ipsilateral CN III palsy, usually

syndrome

tum

with a dilated pupil

• Red nucleus

• Contralateral involuntary

• CN III brachium con-

movements (intention tremor,

junctivum

hemichorea, or hemiathetosis)

Claude's

• Dorsal mesence-

• Ipsilateral CN III palsy, usually

syndrome

phalic tegmentum

with a dilated pupil

• Dorsal red nucleus

• Prominent cerebellar signs

• Brachium conjunc-

• Contralateral involuntary

tivum

movements (nucleus ruber

• CN III

tremor, hemiataxia, and no

hemiballismus)

Parinaud's

• Dorsal rostral mid-

• Paralysis of conjugate upward

syndrome

brain

(and occasionally downward)

• Pretectal area

gaze

• Posterior commis-

• Pupillary abnormalities (disso-

sure

ciation of pupil response close

to light)

• Convergence - retraction nys-

tagmus on upward gaze

• Pathological lid retraction

(Collier's sign)

• Lid lag

• Pseudo-abducens palsy

CN: cranial nerve.

CN: cranial nerve.

CN III n. nucleus (Edinger-Westphal)

superior colliculus medial geniculate body

Substantia nigra cortico-pontine tracts pyramidal tract -(corticospinal)

Benedict Weber Syndrome

syndrome

Weber syndrome

CN III n. nucleus (Edinger-Westphal)

syndrome

Parinaud syndrome

Benedict

Claude Syndrome

Claude syndrome

Parinaud syndrome

Benedict mesencephalic n. CN V

' spinothalamic tracts medial lemniscus mesencephalic reticular formation red nucleus CN III

Claude syndrome a

Fig. 15a

Fig. 15 Brain stem vascular syndromes:

a Midbrain (superior colliculus): Weber syndromes: a) corticospinal and corticopontine tracts (contralateral hemiplegia including the face); b) parasympathetic root fibres of CN III (ipsilateral oculomotor nerve paresis with fixed and dilated pupil); c) substantia nigra (Parkinsonian akinesia). Benedict syndrome: a) red nucleus (contralateral involuntary movements, including intention tremor, hemichorea, and hemiathetosis; b) brachium conjuctivum (ipsilateral ataxia); c) parasympathetic root fibres of CN III (ipsilateral oculomotor paresis with fixed and dilated pupil). Claude syndrome: a) dorsal red nucleus (contralateral involuntary movements, including intention tremor, hemichorea, and hemiathetosis; b)

Marie Foix Syndrome

paramedian raphe superiorcerebellar peduncle middle cerebellar penduncle

mesencephalic motor nuclei -lateral paramedian raphe superiorcerebellar peduncle middle cerebellar penduncle pontine reticular formation pontine nuclei —

Mesencephalic Reticular Formation Nuclei

mesencephalic motor nuclei -lateral

pyramidal tract system pontine reticular formation pontine nuclei —

pyramidal tract lateral pontine syndrome (Marie-Foix syndrome)

pontine reticular formation lateral lemniscus medial lemniscus pyramidal tract - pontine tracts

Raymond-Cestan syndrome

Raymond-Cestan syndrome

Millard Gubler Syndrome
midpontine base syndrome

Fig. 15b brachium conjuctivum (prominent cerebellar signs and no hemiballismus); c) dorsal midbrain tegmentum. Parinaud sydrome: a) superior colliculi (conjugated gaze paralysis upward); b) medial longitudinal fasciculus (nystagmus and internal ophthalmoplegia); c) eventual paresis of the CNs III and IV; d) cerebral aqueduct stenosis/obstruction (hydrocephalus). Involvement of the inferior colliculi produces hearing loss.

b Pons (rostral): Raymond-Cestan syndrome: a) superior cerebellar peduncle (cerebellar ataxia with a coarse "rubral" tremor); b) medial lemniscus and

c inferior cerebellar penduncle pontine reticular formation

CN VIII CN VII

pyramidal tract pontine tracts —

locked-in syndrome

pyramidal tract pontine tracts —

Pyramidal Tract Locked Syndrome

medial lemniscus

- CN V nucleus and tract medial lemniscus

— ventral and lateral spinothalamic tracts

dorsal pontine (Foville) syndrome locked-in syndrome dorsal pontine (Foville) syndrome

Millard Gubler Sendromu
ventral pontine (Millard-Gubler) syndrome

Fig. 15c spinothalamic tract (contralateral decrease in all sensory modalities, involving face and extremities). Ventral extension of the lesion involves additionally; c) corticospinal tract (contralateral hemiparesis), d) paramedian pontine reticular formation (paralysis of the conjugate gaze towards the side of the lesion). Marie-Foix syndrome: a) superior and middle cerebellar peduncles (ispilateral cerebellar ataxia); b) corticospinal tract (contralateral hemiparesis); c) spinothalamic tract (variable contralateral hemihypesthesia for pain and temperature). Midpon-

ventral + lateral spinothalamic tract

inferior olivary nucleus-

medial lemniscus CN XII-

medial lemniscus CN XII-

Multiple Sclerosis Brain Stem

CN VII nuclei

-inferior cerebellar peduncle ambiguus nucleus

-reticular formation pyramidal tract

CN VII nuclei

-inferior cerebellar peduncle ambiguus nucleus

-reticular formation pyramidal tract

Raymond Cestan Syndrome

-lateral medullary

(Wallenberg) syndrome

-lateral medullary

(Wallenberg) syndrome d

Fig. 15d tine base syndrome: a) middle cerebellar peduncle (ipsilateral ataxia and asynergy); b) corticospinal tract (contralateral hemiparesis); c) corticopontine fibres (ipsilateral dystaxia); d) root fibres of CN V (ipsilateral hemianesthesia of all modalities and flaccid paralysis of chewing muscles).

c Pons (caudal): Foville syndrome: a) nucleus and fascicles of CN VII (ipsilateral peripheral type facial palsy), b)nucleus of CN VI (gaze is "away from" the lesion), c) corticospinal tract (contralateral hemiplegia with sparing of the face), d) paramedian pontine reticular formation. Millard-Gubler syndrome: a) pyramidal tract (contralateral hemiplegia sparing the face); b) CN VI (diplopia accentuated when the patient "looks towards" the lesion); c) CN VII (ipsilateral peripheral facial nerve paresis). Locked-in syndrome: a) bilateral corticospinal tracts in the basis pontis (tetraplegia); b) corticobulbar fibres of the lower CNs (aphonia); c) occasionally bilateral fascicles of the CN VI (impairment of horizontal eye movements).

solitary nucleus—

cuneate nucleus and fasciculus

CN V nerve-

nucleus and tract vestibulospinal tract accessory olivary— nucleus solitary nucleus—

cuneate nucleus and fasciculus

CN V nerve-

nucleus and tract vestibulospinal tract accessory olivary— nucleus

Bulbar Lateral Syndrome

Medial medullary syndrome (Dejerine's anterior bulbar syndrome)

— gracile nucleus and fasciculus

- medial lemniscus medullary reticular formation ventral and lateral spinothalamic tract

-CN XII

Medial medullary syndrome (Dejerine's anterior bulbar syndrome)

Fig. 15e d Medulla (rostral): Lateral medullary (Wallenberg) syndrome: a) nucleus and tract of CN V (ipsilateral facial pain and hypalgesia and thermoanesthesia); b) spinothalamic tract (contralateral trunk and extremity hypalgesia and thermoanesthesia); c) nucleous ambiguus (ipsilateral palatal, pharyngeal, and vocal cord paralysis with dysphagia and dysarthria); d) vestibular nuclei (vertigo, nausea, and vomiting); e) descending sympathetic fibers (ipsilateral Horner's syndrome); f) inferior cerebellar peduncle and cerebellum (ipsilateral cerebellar signs and symptoms); g) medullary respiratory centers (hiccups); h) lower pons (diplopia). e Medulla (caudal): Medial medullary (Dejerine) syndrome: a) CN XII (ipsilateral paresis atrophy, and fibrillation of the tongue; b) pyramidal tract (contralateral hemiplegia with sparing of the face); c) medial lemniscus (contralateral loss of position sense and vibration occasionally); d) medial longitudinal nystagmus (upbeat nystagmus).

Pons (Figs. 15band 15c)

Syndrome

Structures involved

Manifestations

Millard-Gubler syn- • Ventral paramedian • Contralateral hemiplegia (spar-drome pons ing the face)

Ipsilateral lateral rectus palsy with diplopia

Ipsilateral peripheral facial paresis

Clumsiness and paresis of the hand, ipsilateral hyperreflexia, and Babinski sign Facial weakness Severe dysarthria and dysphagia

Differential diagnosis: this syndrome has also been described with lesions in a) the genu of the internal capsule or b) with small deep cerebellar hemorrhages.

Dysarthria-clumsy hand syndrome

Ventral paramedian pons

CN VI and VII fascicles

Corticospinal tract

Basis pontis (lacunar infarction) at junction of upper one-third and lower two-thirds of pons CN VII

Pure motor hemiplegia With or without facial involvement

Pure motor hemi- • Lacunar infarction inparesis volving the corticospinal tracts in the basis pontis Ataxic hemiparesis • Lacunar infarction involving the basis pontis at the junction of the upper third and lower two-thirds of the pons

Differential diagnosis: this syndrome has also been described with lesions in a) the contralateral thalamocapsular area, b) the contralateral posterior limb of the internal capsule, and c) the contralateral red nucleus

Hemiparesis more severe in the lower extremity Ipsilateral hemiataxia Occasional dysarthria, nystagmus, and paresthesias

Locked-in syndrome

(deefferentation)

Bilateral ventral pontine lesions (infarction, tumor, hemorrhage, trauma, central pontine my-elinolysis)

Tetraplegia due to bilateral corticospinal tract involvement Aphonia due to involvement of the corticobulbar fibers destined for the lower cranial nerves

Occasionally, impairment of horizontal eye movements due to bilateral involvement of the fascicles ofCNVI

Syndrome

Structures involved

Manifestations

Primary pontine hemorrhage syndromes

Foville's syndrome

Raymond-Cestan syndrome

Marie-Foix syndrome

Classic type (60%): severe pontine destruction

Hemipontine type (20%)

Dorsolateral tegmental type (20%)

Dorsal pontine tegmentum in the caudal third of the pons, PPRF

Rostral lesions of the dorsal pons

Lateral pontine lesions

(especially brachium pontis)

Tetraparesis, coma, and death

Hemiparesis, skew deviation, dysarthria, unilateral absent corneal reflex, CN VII palsy, ipsilateral facial sensory changes, survival with functional recovery Gaze paresis and/or ipsilateral CN VI palsy, unilateral CN VII palsy, contralateral extremity and ipsilateral facial sensory loss, dysarthria, preserved consciousness, motor sparing, occasional gait or limb ataxia

Contralateral hemiplegia (with facial sparing)

Ipsilateral peripheral-type facial palsy (involvement of CN VII fascicles)

Gaze palsy to side of lesion

Cerebellar signs (ataxia) Contralateral reduction of all sensory modalities (face and extremities)

Contralateral hemiparesis Paralysis of conjugate gaze in PPRF involvement Ipsilateral cerebellar ataxia Contralateral hemiparesis Variable contralateral hemihy-pesthesia for pain and temperature

CN: cranial nerve; PPRF: paramedian pontine reticular formation.

Syndrome

Structures involved

Manifestations

Dejerine anterior

• Medial medulla ob

• Ipsilateral paresis, atrophy

bulbar syndrome

longata (corti-

(tongue deviates toward the le-

cospinal tract,

sion)

medial lemniscus,

• Contralateral hemiplegia with

CN XII)

sparing of the face

• Contralateral loss of position and

vibratory sensation. Pain and

temperature sensation are

spared

Wallenberg's syn-

• Lateral medulla

• Ipsilateral facial hypalgesia and

drome

• Inferior cerebellum

thermoanesthesia

(inferior cerebellar

• Contralateral trunk and extrem

peduncle, de-

ity hypalgesia and thermoan-

scending sympa-

esthesia

thetic tract,

• Ipsilateral palatal, pharyngeal,

spinothalamic

and vocal cord paralysis with

tract, CN V nu-

dysphagia and dysarthria

cleus)

• Ipsilateral Horner's syndrome

• Vertigo, nausea, and vomiting

• Ipsilateral cerebellar signs and

symptoms

• Occasionally, hiccups and di-

plopia

Lateral ponto-

• Lateral medulla

• All clinical findings seen in the

medullary syn-

• Inferior cerebellum

lateral medullary syndrome

drome

• Lower pons (to the

• Ipsilateral facial weakness

region of exit of

• Ipsilateral tinnitus and occa

CNs VII and VIII)

sionally hearing disturbance

CN: cranial nerve.

CN: cranial nerve.

en S

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