Brainstem, spinal cord lesions

Question 1

Major focal brainstem lesions

Weber’s syndrome

Site of lesion: Midbrain

clinical features

Answer 1

1. Ipsilateral (same sided) 3rd nerve palsy
2. Contalateral (opposite sided) upper motor neuron type of 7th (facial) nerve palsy
3. Contralateral hemiplegia

Question 2

Major focal brainstem lesion

Perinaud Syndrome

Lesion site: Dorsal midbrain (Tectum)

clinical features

Answer 2

1. Vertical gaze palsy (sunset sign)
2. Convergence squint
3. Convergence retraction nystagmus
4. Pupillary and lid disorders

Cause: Multiple sclerosis, pineal gland tumors

Question 3

Major focal brainstem lesion

Millard Gubler syndrome

Lesion site: Pons (pontomedullary junction)

Answer 3

1. Ipsilateral 6th nerve palsy
2. Ipsilateral lower motor neuron 7th nerve palsy
3. Contralateral hemiplegia

6th nerve supplies: Lateral rectus muscle of eyeball

Question 4

Major focal brainstem lesion

Wallenberg syndrome/lateral medullary syndrome/PICA syndrome

Answer 4

1. Ipsilateral 5th, 9th, 10th, 11th nerve palsy : Lesion to nucleus ambigus
2. Ipsilateral Horner Syndrome : Descending sympathetic fibers damaged
3. Ipsilateral Cerebellar signs : Inferior cerebellar peduncle affected
4. Contralateral spinothalamic sensory loss : damage to Lateral spinothalamic tract & Spinal trigeminal nucleus & tract
5. Vestibular disturbance : Damage to vestibular nuclei.
6. Palatal myoclonus: damage to Central tegmental tract

Clinical features:
1. Lesion to nucleus ambigus causes ipsilateral dysphagia, horseness, absent gag reflex(localizing
lesion - all other deficits are present in lateral pontine syndrome as well)
2. Partial ptosis, miosis & anhidrosis
3. Ataxia, dysmetria, past pointing, dysdiakokinesia
4. Lateral spinothalamic tract - contralateral pain & temperature sensation loss in limbs & torso. Lesion to Spinal trigeminal nucleus & tract causes ipsilateral loss of pain & temperature sensation of face.
5. Vomiting, vertigo, nystagmus

Question 5

Major focal brainstem lesion

Medial Medullary syndrome

Answer 5

1. Contralateral (spastic) hemiparesis (Corticospinal tract lesion)
2. Contralateral impaired tactile discrimination(Contralateral loss of dorsal column sensation) (lesion to Medial leminiscus)
3. Ipsilateral paralysis of tongue muscles (Hypoglossal nerve palsy) Deviation of tongue to side of the lesion

Blood supply: (paramedian branches of anterior spinal artery and/or
vertebral arteries)

Question 6

Major focal brainstem lesion

Claude syndrome

Lesion site: Superior Cerebral peduncle involving red nucleus

Answer 6

1. Ipsilateral 3rd nerve palsy (ipsilateral lateral squint, ptosis, pupil fixed, dilated)
2. Contralateral cerebellar signs (cerebellar ataxia)
3. Loss of accomodation on the site of lesion

Question 7

MEDIAL PONTINE SYNDROME

Answer 7

1. Contralateral spastic hemiparesis: Corticospinal tract lesion
2. Contralateral loss of dorsal column sensation : Medial leminiscus lesion
3. Strabismus/squint (ipsilateral lateral rectus muscle paralysis): CN VI palsy
4. Depending upon the size of the infarct, it can also involve the facial nerve.

Blood supply: paramedian branches of basilar artery

Question 8

LATERAL PONTINE SYNDROME/ AICA syndrome

Answer 8

1. Ipsilateral limb & gait ataxia: Middle & inferior cerebellar peduncle lesion
2. Ipsilateral Horner’s syndrome: Descending sympathetic tract lesion
3. Contralateral loss of pain & temperature from trunk & extremities: Lateral spinothalamic tract lesion
4. Ipsilateral loss of pain & temperature sensation from face: Spinal trigeminal nucleus and tract lesion
5. Nystagmus, nausea, vomiting & vertigo: Vestibular Nuclei damage
6. Ipsilateral LMN facial nerve palsy: Ipsilateral paralysis of face (LMN),Ipsilateral loss of lacrimation & reduced salivation.
   Ipsilateral loss of taste from anterior 2/3 of tongue,Loss of corneal reflex (efferent limb)
7. Hearing loss - ipsilateral central deafness: CN VIII(Cochlear nuclei) damage

ANTERIOR INFERIOR CEREBELLAR OR
CIRCUMFERENTIAL ARTERIES (AICA)