Involuntary Motion Studies

1. Involuntary Motion Studies A summary for study group by David Such

2. Contents • Review of anatomy and physiology • The craniosacral concept • Palpating the cranial rhythm / involuntary motion • Pattern testing • Treatment

3. 1. Review of anatomy & physiology A review of: Osteology of the cranium Meninges Dural partitions / membranes The ventricular system Cerebrospinal fluid Venous sinuses

4. Osteology of the cranium The superior part of the cranium, which houses the brain, is called the cranial vault or the calvaria. The anterior aspect of the cranium is called the facial skeleton or viscerocranium

5. Anterior view of the skull

6. Lateral view of the skull

7. Inferior view of the skull

8. Meninges The meninges are three layers of membranes which surround the brain and SC Dura mater – tough, thick external fibrous layer Arachnoid mater – intermediate, delicate layer Pia mater – innermost area, firmly attached to the surface of the brain

9. Meninges: functions • Protect the brain • Form the supporting framework for arteries, veins and venous sinuses • Form and enclose the subarachnoid space, which contains cerebrospinal fluid

10. Meninges: the layers

11. Meninges: a closer look • Dura mater • Thick, dense, fibrous membrane. Cranial DM has two parts: • Outer periosteal – formed by the periosteum covering the internal surface of the cranial bones, esp @ the sutures, cranial base and foramen magnum • Inner meningeal – continuous with spinal DM. It reflects away from the outer periosteal layer to form dural partitions / membranes • Between these two layers are the dural venous sinuses • Inn’d by CN V1-V3, C1-C3, CN IX & CN X • Arachnoid mater • Surrounds the brain, but does not enter the sulci or fissures • Pia mater • Inner, delicate layer, which closely follows the contours of the brain including the deep sulci and fissures • Between the pia and arachnoid mater is the only ‘real’ space – the subarachnoid space. This is cavity is filled with csf & cerebral blood vv and is supported by arachnoid trabeculae

12. Meninges: innervation Innervation is from: All three branches of CN V CN X Spinal nerves C1-C3 & possibly from CN’s IX & XII

13. Meninges: innervation

14. Dural partitions / membranes The dural partitions project into the cranial cavity forming partial partitions between certain parts of the brain and providing support for other parts.

15. Dural partitions • Falxcerebri • A crescent shaped projection of meningeal DM that passes between the two cerebral hemispheres. Anteriorly it attaches to the frontal crest of the frontal bone and the cristagalli of the ethmoid bone. Posteriorly it attaches and blends with the tentoriumcerebelli • Tentoriumcerebelli • A horizontal shelf that separates the cerebellum from the cerebrum. Posteriorly it is attached to the occipital bone along the grooves for the transverse sinuses. Anteriorly it attaches to the posterior clinoid processes of the sphenoid bone • Falxcerebelli • Separates the two halves of the cerebellum. Superiorly it is attached to the tentoriumcerebelli, whilst posteriorly it attaches to the internal occipital crest of the occiput • Diaphragmasellae • A small horizontal shelf that covers the hypophyseal fossa in the sellaturcica of the sphenoid bone. The infundibilum passes through this membrane, connecting to the pituitary gland

16. Dural partitions

17. The ventricular system Ventricles are cavities within the brain that produce and contain csf. The ventricular system of the brain consists of two lateral ventricles and the midline third and fourth ventricles

18. The ventricular system Each lateral ventricle opens through the interventricular foramina into the third ventricle. This is connected to the fourth ventricle by the cerebral aqueduct. Outflow of csf from here is by the median & lateral apertures and the central canal of the CSp SC

19. The ventricular system

20. Cerebrospinal fluid CSF is a clear, colourless, cell-free fluid that circulates through the ventricles & subarachnoid space that surrounds the brain and SC

21. CSF: functions • Mechanical protection: CSF protects the brain by providing a cushion against physical blows to the head. It is a shock-absorbing medium that adds buoyancy • Chemical protection: CSF provides the optimum chemical environment for accurate neuronal signalling • Nutrition: CSF allows the exchange of nutrients and waste between blood vv and neural tissue

22. CSF: secretion & absorption

23. CSF: secretion & absorption • CSF is produced (at the rate of 400-500ml daily) by the choroidal epithelial cells of the choroid plexuses in the lateral, 3rd & 4th ventricles • These consist of vascular fringes of pia mater covered by cuboidal epithelial cells • CSF is reabsorbed by arachnoid villi (finger-like extensions of arachnoid that project into the dural venous sinuses) which clump together to form arachnoid granulations • On the inner surface of cranial bones, small pits called granular fovea are produced by the pressure of the arachnoid granulations. They are most common on either side of the sagittal suture.

24. CSF: circulation

25. CSF: circulation • Formed in the choroid plexuses of the paired lateral ventricles • Flows into the third ventricle through the intervertebral formania • More CSF is added by the choroid plexus in the roof of the third ventricle • Flows through the cerebral aqueduct, passing through the midbrain, into the fourth ventricle • More CSF produced here as well • CSF then enters the subarachnoid space via the median and lateral apertures, and the SC by the central canal

26. Venous sinuses Venous sinuses are endothelial-lined spaces between the outer periosteal and inner meningeal layers of the cranial dura mater. Large vv from the surface of the brain empty into these sinuses, which then drain into the IJVs

27. Venous sinuses: the main ones Superior sagittal sinus Inferior sagittal sinus Straight sinus Transverse sinus Sigmoid sinus

28. Venous sinuses: locations • Dural venous sinuses are endothelial-lined spaces between the outer periosteal and inner meningeal layers of the cranial dura mater. Lg vv from surface of the brain empty into these sinuses, which then drain into the IJVs • There are 5 main ones: • Sup sagittal sinus Sup border of falxcerebri; sagittal sulcus of frontal bone • Inf sagittal sinus Inf margin of falxcerebri • Straight sinus Continues posteriorly along the junction between the falxcerebri and tentoriumcerebelli to reach the confluence of sinuses • Transverse sinus Passes laterally from the confluence of sinuses forming a groove in the occipital bones • Sigmoid sinus A continuation of the above, marks ‘s-shaped’ grooves in temporal & occipital bones of post cranial fossa – becomes IJV

29. Venous sinuses: cavernous sinuses • The cavernous sinuses are located on either side of the hypophyseal fossa • They receive venous return from both cerebral veins (intracranial) and ophthalmic veins (extracranial) • These connections provide pathways for infections to pass from extracranial sites into intracranial locations

30. Venous sinuses: pterygoid plexus • The pterygoid plexus of veins btwn the medial & lateral pterygoid mm is also connected to the cavernous sinus by small emissary veins • This provides another route by which infection can spread into the cranial cavity from structures such as the teeth • As there are no valves present in emissary veins, misplaced anaesthetic can also backflow into the cranial cavity

31. 2. The craniosacral concept The craniosacral concept Primary respiratory mechanism Reciprocal tension membranes

32. The craniosacral concept • The craniosacral system is characterised by rhythmic, mobile activity which persists throughout life. It is distinctly different from the physiological motions related to breathing and CVS activity(Upledger & Vredevoogd, 1983, p.6) • Sutherland observed mobile articulation at the sutures between the cranial bones • He suggested that there existed (what he termed) a ‘primary respiratory mechanism’ which was the motive force for cranial motion • He believed this mechanism was the result of a rhythmical action by the brain, which led to the repetitive dilation and contraction of cerebral ventricles – thereby promoting a ‘pumping’ of the cerebrospinal fluid • He proposed that intracranial ligaments and fascia act to balance motion within the skull(Chaitow, 2005, p.4)

33. Primary respiratory mechanism • Becker describes this mechanism as a simple, basic, primary, rhythmic unit of function. We are totally dependent on this involuntary mechanism, which can be used as both a diagnostic tool, and a tool for ttt • The five key elements that Sutherland proposed were: • Inherent motility of the CNS • Fluctuation of cerebrospinal fluid • Motility of cranial and spinal dural membranes • Articular mobility of the cranial bones • Involuntary sacral motion between the ilia • Although it has been broken down into five components for teaching purposes, it remains one unit of function

34. Reciprocal tension membranes • The cranial term for the dural membranes • They are the: • Falxcerebri • Falxcerebelli • Tentoriumcerebelli • Diaphragmasellae • They are continusuly under dynamic tension so that change in one requires adaptive change in another (Chaitow, 2005, p.4)

35. Reciprocal tension membranes • Greenam suggests that the continuation of the cranial meningeal dura mater with the spinal dura mater, and the subsequent att’s of this to the sacrum, provide a direct link between cranial and sacral motion • The cranium produces a traction via the dura mater – which moves the sacrum rhythmically (Chaitow, 2005, p.6)

36. 3. Palpating the cranial rhythm Flexion & extension phases Flexion & extension at the cranium Flexion & extension at the sacrum Hand holds

37. Flexion & extension phases • During the flexion phase of the craniosacral motion cycle, the whole body externally rotates and broadens • During the extension phase the body internally rotates and seems to narrow slightly • A complete cycle of the craniosacral rhythmic motion is composed of one FLX and one EXT phase • The normal rate of the craniosacral rhythm is between 6-12 cycles per minute

38. Flexion & extension at the cranium Transverse widening AP shortening Vertical shortening Transverse narrowing AP lengthening Vertical lengthening

39. Flexion & extension at the sacrum • Involuntary motion appears at the sacrum as a gentle rocking motion about a transverse axis located approx 1 inch anterior to the 2nd sacral segment • Flexion • Sacral apex moves anteriorly whilst the sacral base moves posteriorly (ie. counternutation) • There is a flattening/flexion of the LSp lordosis • Extension • Sacral apex moves posteriorly whilst the sacral base moves anteriorly (ie. nutation) • There is a hollowing/extension of the LSp lordosis

40. Hand holds • Cranium • Ideally the second finger needs to be on the greater wing of the sphenoid and the fifth finger round the lateral margin of the occiput, so the cranial vault is being cradled • (Chaitow, 2005, p. 40) • Sacrum • The sacrum should sit in the Op’s hand such that the apex is at the interthenarsulcus. The sacral spine should then lie between the third and fourth fingers • (Upledger & Vredevoogd, 1983, p. 34)

41. 4. Pattern testing Pattern testing takes place at the suture between the basilar part of the occiput and the sphenoid This is also know as the sphenobasilar synchondrosis/symphysis (SBS or SSB) – see note Patterns are grouped into: Physiological Non-physiological

42. Physiological • Flexion / extension • Torsion (two opposing rotations) • Side bending & rotation • Asymmetries or distortions occuring at the SBS may result in altered tensions in the dural membranes. This will affect their ability to adapt and compensate • The lesion is named for the direction toward which the cranial base moves with the greatest facility

43. Flexion / extension

44. Torsion

45. Side bending & rotation

46. Non-physiological • Vertical displacement • Lateral displacement • Compression

47. Vertical displacement

48. Lateral displacement

49. Compression

50. 5. Treatment Balanced Membranous Tension CV4