Meninges of Spinal Cord and clinical Correlation By Dr. Rabia Inam Gandapore.pptx

Neuroanatomy

1. Meninges of Spinal Cord & Clinical Relevance Dr. Rabia Inam Gandapore Assistant Professor Head of Department Anatomy (Dentistry-BKCD) B.D.S (SBDC), M.Phil. Anatomy (KMU), Dip. Implant (Sharjah, Bangkok, ACHERS) , CHPE (KMU),CHR (KMU), Dip. Arts (Florence, Italy )

2. Teaching Methodology LGF (Long Group Format) SGF (Short Group Format) LGD (Long Group Discussion, Interactive discussion with the use of models or diagrams) SGD (Short Group) SDL (Self-Directed Learning) DSL (Directed-Self Learning) PBL (Problem- Based Learning) Online Teaching Method Role Play Demonstrations Laboratory Museum Library (Computed Assisted Learning or E-Learning) Assignments Video tutorial method

3. Goal/Aim (main objective) To help/facilitate/augment the students about the : Explain structural features, blood & nerve supply of meninges of spinal cord.

4. Specific Learning Objectives (cognitive) At the end of the lecture the student will able to: Explain structural features, blood & nerve supply of meninges of spinal cord. Enumerate relevant clinical problems

5. Psychomotor Objective: (Guided response) A student to draw labelled diagram of meninges of spinal cord

6. Affective domain To be able to display a good code of conduct and moral values in the class. To cooperate with the teacher and in groups with the colleagues. To demonstrate a responsible behavior in the class and be punctual, regular, attentive and on time in the class. To be able to perform well in the class under the guidance and supervision of the teacher. Study the topic before entering the class. Discuss among colleagues the topic under discussion in SGDs. Participate in group activities and museum classes and follow the rules. Volunteer to participate in psychomotor activities. Listen to the teacher's instructions carefully and follow the guidelines. Ask questions in the class by raising hand and avoid creating a disturbance. To be able to submit all assignments on time and get your sketch logbooks checked.

7. Lesson contents Clinical chair side question: Students will be asked if they know what is the function of Outline: Activity 1 The facilitator will explain the student's about Meninges of spinal cord Activity 2 The facilitator will ask the students to make a labeled diagram of Meninges of spinal cord Activity 3 The facilitator will ask the students a few Multiple Choice Questions related to it with flashcards.

8. Recommendations Students assessment: MCQs, Flashcards, Diagrams labeling. Learning resources: Langman’s T.W. Sadler, Laiq Hussain Siddiqui, Snell Clinical Anatomy , Netter’s Atlas , BD Chaurasia’s Human anatomy, Internet sources links.

9. Meninges of Spinal Cord

10. 1. Dura Mater D ense , strong, fibrous membrane that encloses spinal cord & cauda equina . Its continuous above through foramen magnum with meningeal layer of dura covering brain . Inferiorly: it ends on filum terminale at level of lower border of S2 vertebra . D ural sheath lies loosely in vertebral canal & is separated from the wall of canal by extradural space . It contains loose areolar tissue & internal vertebral venous plexus . It extends along each nerve root & becomes continuous with the connective tissue surrounding each spinal nerve (epineurium ). I nner surface of dura mater is in contact with arachnoid mater .

11. 2. Arachnoid Mater D elicate impermeable membrane that covers spinal cord Lies between pia mater internally & dura mater externally . Its separated from pia mater by subarachnoid space filled with CSF & is crossed by a number of fine strands of connective tissue . Its continuous above through foramen magnum with arachnoid covering brain . Inferiorly , it ends on filum terminale at level of lower border of S2 vertebra . It continues along spinal nerve roots , forming small lateral extensions of subarachnoid space .

12. 3. Pia Mater V ascular membrane that closely covers spinal cord is thickened on either side between the nerve roots to form the ligamentum denticulatum , which passes laterally to adhere to arachnoid & dura . Via this spinal cord is suspended in middle of dural sheath . It extends along each nerve root & becomes continuous with the connective tissue surrounding each spinal nerve .

13. Clinical Relevance

14. Excessive Movements of Brain Relative to Skull & Meninges in Head Injuries M oving patient's head is suddenly halted, momentum of brain causes it to travel onward until its movement is resisted by skull or strong septa of dura mater . L ateral movements : lateral surface of one hemisphere hits side of skull & medial surface of opposite hemisphere hits side of falx cerebri . S uperior movements: superior surfaces of cerebral hemispheres hit vault of skull & superior surface of corpus callosum hits s harp free edge of falx cerebri ; superior surface of cerebellum presses against the inferior surface of tentorium cerebelli . Movements of brain relative to skull & dural septa injure the cranial nerves & Fragile cortical veins that drain into dural sinuses torns , resulting in severe subdural or subarachnoid hemorrhage . Arteries (strong walls) rarely damaged.

15. Intracranial Hemorrhage & Meninges 1. Epidural Hemorrhage : results from injuries to meningeal arteries or veins . Middle Meningeal Artery (anterior division): most common damaged at pterion suture Bleeding occurs & strips up meningeal layer of dura from internal surface of skull . I ntracranial pressure rises & enlarging blood clot exerts local pressure on underlying motor area in the precentral gyrus . (Lucid interval ) Blood also passes laterally through the fracture line to form a soft swelling under temporalis muscle. To stop hemorrhage , torn artery or vein must be ligated or plugged. B urr hole through skull wall should be placed about 1-1/2 inches (4 cm) above the midpoint of zygomatic arch .

16. Computed Tomography Scans of Epidural & Subdural Hematomas blood clots seen on CT scans E pidural hemorrhage , blood strips up meningeal layer from endosteal layer of dura ( periosteum of skull), producing a lens-shaped hyper dense collection of blood that compresses brain & displaces midline structures to opposite side . The shape of blood clot is determined by the adherence of meningeal layer of dura to periosteal layer of dura .

17. 2. Subdural Hemorrhage R esults from tearing of superior cerebral veins at point of entrance into superior sagittal sinus . Cause: blow on f ront or back of head , causing excessive antero -posterior displacement of brain within skull . Acute & chronic forms of condition occur

18. Subdural hematoma , blood accumulates in extensive potential space between meningeal layer of dura & arachnoid , producing a long crescent-shaped, hyper dense rim of blood that extends from anterior to posterior along the inner surface of skull. With a large hematoma, brain sulci are obliterated & midline structures are displaced to opposite side.

19. Intracranial Hemorrhage in Infant Intracranial hemorrhage may occur during birth & result from excessive molding of head . Bleeding may occur from cerebral veins or venous sinuses . Excessive anteroposterior compression of head often tears anterior attachment of falx cerebri from tentorium cerebelli . Bleeding then takes place from great cerebral veins, straight sinus or inferior sagittal sinus ( shaken-baby syndrome ).

20. Headache B rain is insensitive to pain Headaches Due to stimulation of receptors outside brain

21. Meningeal Headaches D ura mater receives its sensory nerve supply from trigeminal & first three cervical nerves. Dura above tentorium: innervated by trigeminal nerve & headacheis referred to forehead & fa ce. D ura below tentorium: innervated by cervical nerves & headache is referred to back of head & neck. Meningitis, or inflammation of meninges: causes severe headache over entire head & back of neck .

22. Headaches Caused by Cerebral Tumors Expanding tumor & raised intracranial pressure produces severe, continuous & progressive headache caused by irritation & stretching of dura . Tumor above tentorium: produce a headache referred to front of head T umor below tentorium: produces a headache referred to back of head .

23. Migraine Headache Common, can be unilateral or bilateral, recurring at intervals & associated with prodromal visual disturbances . P rodromal visual disturbances are thought to be due to sympathetic vasoconstriction of cerebral arteries supplying visual cortex . D ilatation & stretching of other cerebral arteries & branches of external carotid artery & affect arteries both inside & outside skull & cause is unknown, although genetic, hormonal & biochemical factors may initiate an attack. b eta-blockers bring relief due to reduction in cerebral vasodilation.

24. Alcoholic Headache D ue to direct toxic effect of alcohol on meninges.

25. Headaches Due to Diseases of Teeth, Paranasal Sinuses & Eyes Dental infection & sinusitis are common causes of headache. Pain is referred to skin of face & forehead along the branches of trigeminal nerve . Tonic spasm of ciliary muscle of eye , when attempting to focus on an object for prolonged periods (e.g., reading small print), may cause severe orbital headache & commonly occurs in individuals who need lenses for correction of presbyopia

26. Clinical Problems of Venous Sinuses Thrombosis of cavernous sinus Pulsating exophthalmos (protrusion of the eyeball) due to thrombosis or increased pressure in the cavernous sinus or superior sagittal sinus.

27. Thank You Any Questions?