BRAINSTEM

DR ANIL DWIVEDI

GROSS ANATOMY OF THE BRAINSTEM

THE MEDULLA: GROSS ANATOMY

INTERNAL STRUCTURE OF THE MEDULLA

THE PONS GROSS ANATOMY

PONS - L. – a bridge

INTERNAL STRUCTURE OF THE PONS

THE MIDBRAIN GROSS ANATOMY

INTERNAL STRUCTURE OF THE MIDBRAIN

BLOOD SUPPLY OF BRAINSTEM

BLOOD SUPPLY

• MEDULLA1. 2 VERTEBRAL A2. ANT &POST SPINAL A3. ANT &POST INF CEREBELLAR A4. BASILAR A

PONS

• PONTINE BRANCHES OF BASILAR A• ANT INF CEREBELLAR A

MIDBRAIN

• BASILAR A-DIRECT BRS• POST CEREBRAL A• SUP CEREBELLAR A• BRS OF POST COMM &ANT CHOROIDAL A

Syndromes

Wallenberg Syndrome• aka lat medullary syndrome• occ. of PICA• Posterolat part of medulla is

damaged• Features:

a) Inv of spinal nuc & tract of V nerve

- ipsilateral loss of pain & temp from face & forehead

b) Inv of spinal lemniscus (lat spinothalamic tract) –

-contralateral loss of pain & temp from body below face

c) Inv of nuc. Ambiguus –

- paralysis of muscles of soft palate, pharynx & larynx-

- dysarthria & dysphagia

d) Inv of Vestibular nuclei - - giddiness

This combination of sensory loss – “Crossed Hemianaesthesia”

Click to edit the outline text format Second Outline

Level Third Outline

LevelFourth

Outline Level Fifth

Outline Level

Sixth Outline Level

Seventh Outline Level

Eighth Outline Level

• Ninth Outline LevelClick to edit Master text styles– Second level

• Third level– Fourth level

» Fifth level

Medial Medullary Syndrome

Dejerine’s ant bulbar syndrom.b/c vertebral a XII nerve – i/l paralysis &

atrophy of 1/2 tongue ; deviated to affected side

Pyramid c/l hemiplegia/ paralysis arm & leg.

medial lemniscus (post column fibres) - contralateral loss of position & vibra.

This combination of motor loss – Crossed motor paralysis

Millard-Gublar synd

• Lesion in lower part of Pons• Incl pyramidal tract• Also inv 6 & 7 nerve fibers• Abd n. i/l med squint• Facial n i/l facial palsy• Corticospinal tract c/l hemiplegia

Pontine H’age• Pontine arteries rupture • Hyperpyrexia – thermoregulatory mech.

disrupted• Pinpoint pupils – contraction of sphincter

pupillae muscle• Coma – reticular formation lesion• Contralateral UMN paralysis – pyramidal

fibres involved

Click to edit the outline text format Second Outline

Level Third Outline

LevelFourth

Outline Level Fifth

Outline Level

Sixth Outline Level

Seventh Outline Level

Eighth Outline Level

• Ninth Outline LevelClick to edit Master text styles– Second level

• Third level– Fourth level

» Fifth level

Weber's Syndrome

• Ipsilateral oculomotor palsy.

• Contralateral hemiplegia

Click to edit the outline text format Second Outline

Level Third Outline

LevelFourth

Outline Level Fifth

Outline Level

Sixth Outline Level

Seventh Outline Level

Eighth Outline Level

• Ninth Outline LevelClick to edit Master text styles– Second level

• Third level– Fourth level

» Fifth level

Benedikt's syndrome

• Fibres of III nerve.

• Descending motor fibres in cerebral peduncle.

• Red nucleus and nearby cerebellothalamic fibres.