Cerebral circulation and brain stem syndromes

1. CEREBRAL CIRCULATION AND BRAINSTEM SYNDROMES Presenter – Dr.Goutham Moderator- Dr.SRIVANI MD

2. THE BRAIN •Large mass of nervous tissue located in cranialcavity. •Has four major regions. Cerebrum (Cerebral hemispheres) Diencephalon: Thalamus, Hypothalamus, Subthalamus & Epithalamus Cerebellum Brainstem: Midbrain, Pons & Medulla oblongata

3. BLOOD SUPPLY OF BRAIN • Brain Receives 17% of cardiac output • Consumes 20% of entire Oxygen used by the body • 10 seconds of interruption in blood flow leads to unconsciousness • Most neurologic disorders are due to vascular lesions

4. ANTERIOR AND POSTERIOR CIRCULATIONS • Anterior – Internal carotid arteries • Posterior – Vertebral arteries

5. ANTERIOR CIRCULATION INTERNAL CAROTID artery Course it arises from the common carotid artery at the level of c4 vertebrae • Enters into Middle cranial fossa through carotid canal and then enters through foramen lacerum into cavernous sinus Pierces dura and arachnoid maters. • It ends by Dividing into Anterior and Middle cerebral arteries.

6. Branches of internal carotid artery 1. Opthalmic artery 2. Posterior communicating artery 3. Anterior choroidal artery 4. Bifurcates into anterior cerebral artery and middle cerebral artery .

7. ANTERIOR CHOROIDAL ARTERY • Branch of internal carotid artery • Supplies posterior limb of internal capsule, retrolentiform and sublentiform parts • Complete syndrome rare due to collaterals from MCA, PCA, and ICA • Syndrome comprises • c/l hemiplegia • c/l hemianaesthesia • c/l homonymous hemianopia

8. Anterior cerebral artery the two anterior cerebral arteries joined together by anterior communicating artery. • Brain supplied by anterior cerebral artery Frontal pole Medial aspects of frontal and parietal lobes Basal ganglia Corpus callosum

9. Anterior Cerebral artery A1 segment- proximal to anterior communicating artery it gives branches to anterior limb of internal capsule anteroinferior caudate anterior hypothalamus A1 segment occlusion are rarely produces clinical syndrome because collateral flow through anterior communicating artery and collaterals from MCA and PCA

10. A2 SEGMENT • Part of anterior cerebral artery distal to anterior communicating artery • supplies frontal pole , entire medial part of frontal and parietal lobe. A2 SYNDROME Lesion of A2 segment causes paralysis and sensory loss of C/L foot and leg and involvement of paracentral lobule causes urinary incontinence.

11. MIDDLE CEREBRAL ARTERY • It arises from the internal carotid and continues into the later sulcus where it then branches and projects to lateral cerebral cortex.

12. Middle cerebral Artery M1 SEGMENT(proximal)-it gives deep penetrating or lenticulostriate branches which supplies Internal capsule, caudate nuclues, putamen and outer pallidus M1 SYNDROME-occlusion of lenticulostriate branches- Involvement of internal capsule produces contralateral hemiplegia. Involvement of putamen, pallidus- leads to parkinsonian features.

13. Blood supply of internal capusle Upper part ; lenticulo striate braches of MCA LOWER PART : anterior chorodial artery

14. M2 Segment It has superior and inferior divisions supplies the entire superiolateral surface of cerebral hemispheres . Except • frontal pole • strip along the superiomedial frontal and parietal cortex • medial temporal cortex • occipital lobe

15. M2 syndromes • If superior division involved • Brachial syndrome- weakness of hand and arm • Frontal opercular syndrome-Brocas aphasia with facial weakness with or without arm weakness • proximal part of the superior division involved- clinical features of motor weakness, sensory disturbances and brocas aphasia • If inferior division of M2 involved- • If dominant hemisphere- Wernickes aphasia without weakness with contralateral homonymous superior quadrantanopia • If non dominant hemisphere- Hemispatial neglect , spatial agonosia without weakness

16. Complete MCA syndrome • occulsion of both M1 AND M2 SEGEMENT IS COMPLETE MCA SYNDROME. CLINICAL FEATURES • Contralateral hemiplegia • Contralateral hemianaesthesia • Contralateral homonymous hemianopia • If dominant hemisphere involved-Global aphasia • If non dominant hemisphere involved- Hemispatial neglect, and constructional apraxia

17. CIRCLE OF WILLS o It is Formed by: Two Anterior cerebral arteries Two Internal carotid arteries Two Posterior cerebral arteries Two Posterior communicating arteries One Anterior communicating artery

18. Branch of subclavian artery

19. • Structures Supplied by posterior circulation • Cerebellum • Medulla • Pons • Midbrain • Thalamus • Subthalamus • Hippocampus • Medial part of temporal lobe • Occipital lobe

20. Posterior cerebral artery •P1 segment-proximal PCA supplies to - Midbrain, thalamus and subthalamus •P2 segment- distal PCA supplies to Temporal and occipital cortex.

21. P1 syndromes •Due to the involvement of ipsilateral subthalamus, cerebral peduncles and midbrain

22. Posterior Cerebral Artery • P1 Syndromes Syndrome Clinical features Localization Claude’s syndrome 3rd nerve palsy contralateral ataxia Rednucleus / cerebral peduncle Weber’s syndrome 3rd nerve palsy hemiplegia Medial mid brain / cerebral peduncle Benedikt’s syndrome 3rd Nerve palsy hemiplegiaAtaxia Rednucleus / Medial mid brain Subthalamic nucleus Contralateral hemiballismus thalamic Déjerine-Roussy syndrome contralateral hemisensory loss and agonizing pain thalamus

23. P2 syndromes • ANTONS SYNDROME-bilateral occlusion in distal PCAs – bilateral occipital lobe infarction- cortical blindness and patient often unaware and even deny it • BALINTS SYNDROME-bilateral visual association areas- palinopsia and asimultagnosia

24. Blood supply of brain stem Structure Blood supply Midbrain Posterior cerebral artery Pons Basilar artery, superior cerebellar artery Medulla Vertebral artery Posterior inferior cerebellar artery

25. Midbrain Syndromes

26. Syndrome Lesion location Structures involved Clinical features Comment webers Midbrain base CN-3 fibers , cerebral peduncle Ipsilateral 3-CN palsy, Contralateral hemiplegia Usually vascular in origin Claude’s Midbrain tegmentum CN-3 fibers , red nucleus , Superior cerebellar peduncle. IpsilateraL 3-CN palsy, Rubral tremors, ContralateraL ataxia Usually vascular in origin Benedikt’s Midbrain tegmentum CN-3 fibers , red nucleus , Cerebral peduncle, Superior cerebellar peduncle IpsilateraL 3-CN palsy, Rubral tremors, ContralateraL hemiplegia, Contralatera ataxia Usually vascular in origin Nothnagel’s Midbrain tectum(roof) Ipsilateral OR BilateraL 3-CN, Superior cerebellar peduncle 3rd-CN palsy, Contralateral ataxia Neoplastic in origin Parineaud’s Midbrain dorsum Periaqueductal gray matter Impaired upward gaze Usually due to mass lesion in the 3rd

27. Pontine syndromes syndrome Lesion location Structures involved Clinical features Comment Millard-Gubler Pons Facial nerve nucleus Cortico spinal tract Ipsilateral facial nerve palsy, Contralateral hemiparesis Usually vasucular Foville’s Pons Facial nerve nucleus Cortico spinal tract Lateral gaze center Ipsilateral facial nerve palsy, Contralateral hemiparesis, Horizontal gaze palsy. Usually vasucular Raymond’s Pons 6 th cranial nerve (abducence) Cortico spinal tract Ipsilateral 6th nerve palsy, Contralateral hemiparesis, Usually vasucular

28. Lateral medullary syndrome(Wallenburgs) Structure Clinical features Spinothalamic tract Contralateral decreased pain and temperature Spinocerebellar tract Ipsilateral ataxia Sympathetic fibers Horners syndrome Spinal trigeminal tract and nucleus(5th) Pain and numbness over Ipsilateral half of the face Nucleus ambiguus Dysphagia,hoarseness Vestibular nuclei Vertigo,nausea

29. Medial medullary syndrome Structure involved Clinical features pyramid Contralateral hemiplegia medial lemniscus contralateral loss of tactile and proprioception hypoglossal nerve nucleus (12 th) Ipsilateral atrophy of half of tongue.

30. Thank u…

Cerebral circulation and brain stem syndromes

DrRudra Naresh

Cerebral circulation and brain stem syndromes