Cranial Field (Curtis)

Question 1

History

Answer 1

William G. Sutherland, D.O., D.Sc. (Hon) was (1873-1954) was an early student of Dr. A.T. Still
1899- observed a disarticulated skull in the hallways of the American School of Osteopathy
“As I stood looking and thinking in the channel of Dr. Still’s philosophy, my attention was called to the beveled articulate surfaces of the sphenoid bone. Suddenly there came a thought; I call it a guiding thought- beveled, like the gills of a fish, indicating articular mobility for a respiratory mechanism.”
Potential for cranial motion
Immediately dismissed the thought, but kept returning to it
Practiced, studied, researched (on himself) in Minnesota for 30 years before beginning to share his discovery with his colleagues
His discovery and teachings clarify and expand on the science of osteopathy

Question 2

Osteopathy in the Cranial Field

Answer 2

OCF is not limited to cranial
The inherent force functions throughout the entire body
Diagnosis and treatment of the cranium affects the entire body and vice versa
“It is a thought that is no way apart from the science of osteopathy… It is not a specialty in itself; it not simply a therapy. We are dealing with a science.” -WGS

Question 3

Primary Respiratory Mechanism

Answer 3

Primary:
First in importance, precedes thoracic respiration
Physiologic centers at the floor of fourth ventricle regulate pulmonary respiration, circulation, digestion, and elimination, and depend on the function of the CNS
Primary in maintenance of life

Respiratory:
Exchange of gases and other metabolites at the cellular level

Mechanism:
An integrated machine, each part in working relationship to every other part

Question 4

5 Phenomena

of the respiratory mechanism

Answer 4

Fluctuation of cerebrospinal fluid
Inherent rhythmic motion of the brain and spinal cord
Mobility of intracranial and intraspinal membranes
Articular mobility of cranial bones
Involuntary mobility of sacrum between the ilia

Question 5

Fluctuation of CSF

Answer 5

CSF formed by choroid plexuses in lateral, third, and fourth ventricles
- Circulates through the ventricles, over and around brain and spinal cord, through subarachnoid spaces and cisternae, reabsorbed by choroid plexus

CSF bathes, protects, nourishes CNS

Fluctuation: a wavelike motion of fluid in a natural/artificial cavity

• Observed by palpation or percussion (and MRI studies)
• Provides a continuous mixing of CSF
• Circulatory forces alone are inadequate

Well-studied

Question 6

Inherent Rhythmic Motion of CNS

Answer 6

Subtle, slow, pulse-wavelike movement

Coiling and uncoiling

Biphasic cycle, may be rhythmic

Measurable

Well-studied and established

Four definite motions observed during operation (neurosurgery):

1. A pulsation synchronous with cardiac contractions
2. A pulsation coinciding with thoracic respiration
3. A wave of constant rate not related to either
4. An undulating pulsation not related to either

Question 7

Mobility of Intracranial and Intraspinal Membranes

Answer 7

The meninges surround, support, and protect the CNS

Intracranial membranes are intimately related to the fascia of the rest of the body through foramina in the cranial base and throughout the entire spine, the foramen magnum, and all fascial attachments to the undersurface of the cranial base

In the developing & newborn skull, the dura * maintain the shape and stability* of the cranium
No interlocking sutures, only fully formed articulation in the cranium is the occipital condyles and the atlas

In the fully formed skull, the reciprocal tension membrane serves to guide and limit the motion of the cranial bones

Question 8

Dura mater:

Answer 8

Outermost of the 3 meningeal coverings, composed of 2 layers of tough fibrous tissue

Outer layer: lines cranial cavity, forms periosteal covering for inner aspect of the bones, and extends through the sutures of the skull to become continuous with the periosteum on the outer surface of the skull
- Membranous bag around each cranial bone

Inner layer: covers the brain and spinal cord, and has reduplications (falx cerebri, tentorium cerebelli, falx cerebelli)
- Protects the brain

Layers are inseparable except where they split to form venous sinuses

Question 9

Dura mater reduplications:

Answer 9

Falx cerebri:
Arises from straight sinus at the internal occipital protuberance (externally at inion)
Rises to lambda, continues across sagittal suture (parietals) to bregma, down metopic suture (frontal) to crista galli of ethmoid
Sits between cerebral hemispheres

Tentorium cerebelli:
Arises from straight sinus at the internal occipital protuberance
Arches across posterior angle of the parietal along the length of the petrous portion of the temporal bone, attaching to the clinoid processes of the sphenoid
Lies horizontally between cerebellum and occipital lobes, 1 on each side

Falx cerebelli:
Arises from straight sinus at the internal occipital protuberance, arcs down the occipital squama to attach firmly at foramen magnum, continuous with dura of spinal canal
Lies between two hemispheres of cerebellum

Question 10

Dura mater attachments and surrounds

Answer 10

Inner layer only extends down spinal canal with firm attachments at

• Foramen magnum
• C2-C3
• Lower lumbar*
• S2

Surrounds all spinal roots and is continuous with epineurium lateral to dorsal root ganglion

Responds to motion of CNS and fluctuations of CSF, influencing cranium, sacrum

**“Core Link:”
Reciprocal Tension Membrane that links cranium to sacrum
Trauma, strain that affects one part of the mechanism affects other parts

Question 11

Reciprocal Tension Membrane

Answer 11

All membranes change shape during the phases of the primary respiratory mechanism
Balances and maintains a constant level of tension during the rhythmic, simultaneous alternating shape change of the PRM
Functions around an automatically shifting fulcrum along the straight sinus, not a fixed anatomical point
Sutherland fulcrum
Each sickle moves in an arc like movement
With the flexion/ inhalation phase, the A/P diameter is reduced by the sickle-like movement
The tent flattens and widens
The core link (spinal dura) lifts the sacrum, moving it into the counternutation position

Question 12

Articular Mobility of Cranial Bones

Answer 12

At birth, cranial bones are smooth-edged osseous plates with membrane and/or cartilage between them

With normal growth, the edges of the cranial bone plates develop and come together with sutures (joints) between them
- In many causes, may never completely close

These sutures allow for a minimal amount of motion and protect the brain

“Although the skull is often assumed to be a rigid container with a constant volume, many researchers have demonstrated that the skull moves on the order of a few micrometers in association with changes in intracranial pressure” – NASA research team

Question 13

Involuntary Mobility of Sacrum Between Ilia

Answer 13

The sacrum has several axes of motion

Moves on one or several postural axes in relation to the ilia

Responds to inherent mobility of CNS, fluctuation of SCF, pull of membranes
- Occurs around a transverse axis (respiratory axis) anterior to S2

PRM intimately related to the rest of the body through its fascial connects

Question 14

anatomy

Answer 14

make sure to look at the slides for an anatomy review

Question 15

Venous Sinuses- general

Answer 15

Lie between the 2 layers of dura
Lack smooth muscle, elastic fibers, valves, and proximity to skeletal muscle (all of which usually propels blood through veins)
Depend on mobility of dura to promote drainage

Question 16

venous sinuses- specific

Answer 16

Superior sagittal sinus

Inferior sagittal sinus

Straight sinus

Occipital sinus:

Transverse sinuses:

Sigmoid sinuses:

Question 17

Superior sagittal sinus:

Answer 17

Attached portion of the falx cerebri

Drains to R transverse sinus/ confluence of sinuses

Question 18

Inferior sagittal sinus

Answer 18

Free border of falx cerebri

Drains to straight sinus

Question 19

Straight sinus

Answer 19

Lies in junction of falx cerebri and tentorium cerebelli

Drains to L transverse sinus/ confluence of sinuses

Question 20

Occipital sinus

Answer 20

Lies in attached portion of falx cerebelli

Drains to L transverse sinus

Question 21

Transverse sinuses:

Answer 21

Lie in attached border of the tent from confluence of sinuses to the parietal angle
Drains into sigmoid sinuses

Question 22

Sigmoid sinuses:

Answer 22

Lie along mastoid angle of the temporal and jugular processes of the occiput
Terminal drainage of the venous sinus system in to the internal jugular vein in the jugular foramen

Question 23

95% of venous blood from cranium drains into

Answer 23

internal jugular vein
Jugular foramen (between occiput and temporal bones)
Compression/restriction of the area can have damaging effects on venous drainage from the entire head

Question 24

midline (unpaired) bones of the cranium. How do they move?

Answer 24

Vomer
Ethmoid (median plate)
Sphenoid
Occiput
\+ Sacrum

Move through flexion and extension around a transverse axis

Question 25

Bilateral (Paired)

bones of the cranium. How do they move?

Answer 25

Mandible*
Maxillae
Zygomae
Palatines
Nasals
Lacrimals
Frontal*
Temporals
Parietals
Ethmoid (lateral mass)
Move through external and internal rotation

• • act as paired bones

Question 26

SBS

Answer 26

Sphenobasilar Synchondrosis 
Sphenobasilar Symphysis
SBS
Where sphenoid articulates with occiput
Cartilaginous until age 20-25 years, then has the resiliency of cancellous bone
Exhibits flexibility

Question 27

Physiologic Motion

Answer 27

Flexion and extension are occurring in response to a pull or influence from the membranes, which is influenced by the coiling and uncoiling of the CNS and the fluctuation of the CSF
Inherent or involuntary motion
Not visible, but palpable
Motion is a resiliency
“Do not look for movement as in other joints of the body. This is merely a resiliency – a combination of slight yielding or suppleness in the articulation plus the flexibility of live and pliant bone.”
– Magoun

Question 28

Physiologic Strain Patterns- general

Answer 28

The SBS is the reference point around which diagnostic motion patterns are described
These general patterns represent the adaptation of the cranium to strain
The strain may be a result of dysfunction anywhere in the body
Or an accommodation of trauma to the cranium itself

Question 29

Primary Respiratory Mechanism:2 Phases

Answer 29

Flexion and Extension

Question 30

things associated with Flexion

Answer 30

Inhalation
Elevation of the sphenobasilar junction 
Midline bones rotate about a transverse action into flexion
Paired lateral bones move into external rotation
Decreased AP diameter
Increased transverse diameter
Tent. cerebelli flattens, widens
Sacrum counternutates

Question 31

things associated with Extension

Answer 31

Exhalation
Lowering of the sphenobasilar junction
Midline bones rotate about a transverse action into extension
Paired lateral bones move into internal rotation
Increased AP Diameter
Decreased transverse diameter
Tent. cerebelli peaks
Sacrum nutates

Question 32

description of flexion

Answer 32

Rotational motion around 2 transverse axes

1. Occiput: Directly superior to foramen magnum
2. Sphenoid: Through the body of the sphenoid

Basiocciput and basisphenoid move superiorly

Occipital squama and wings of sphenoid move inferiorly

Bregma (joining of coronal and sagittal sutures) descends
Paired bones externally rotate

Sacrum

• Base moves posteriorly
• Apex moves anteriorly
• About a transverse axis through the second sacral segment

Question 33

description of extension

Answer 33

Rotational motion around 2 transverse axes

1. Occiput: Directly superior to foramen magnum
2. Sphenoid: Through the body of the sphenoid

Basiocciput and basisphenoid move inferiorly

Occipital squama and wings of sphenoid move superiorly

Bregma (joining of coronal and sagittal sutures) ascends
Paired bones internally rotate

Sacrum

• Base moves anteriorly
• Apex moves posteriorly
• About a transverse axis through the second sacral segment

Question 34

Types of physiologic strain patterns

Answer 34

Ideally, the PRM moves through the flexion and extension phases equally and fully

These general patterns represent the adaptation of the cranium to strain

The strain may be a result of dysfunction anywhere in the body

Or an accommodation of trauma to the cranium itself

Types of Physiologic Strain Patterns:
Extreme/ exaggerated flexion with decreased extension
Extreme/ exaggerated extension with decreased flexion
Torsion
Sidebending/Rotation

Question 35

bert and ernie in phyiologic strain patterns

Answer 35

Flexion
Forehead wide and sloping
Prominent eyes
Protruding ears

Extension:
Forehead vertical
Receded eyes
Ears close to head

Question 36

Torsion

Answer 36

Twist at SBS
Rotation of the SBS along an anteroposterior axis that runs through nasion to opisthion
Sphenoid and occiput rotate in opposite directions
Named for the side of the high greater wing of the sphenoid
“Right torsion” = GW higher on the right

Question 37

Sidebending Rotation

Answer 37

Sidebending rotation are two separate motions of the SBS that occur simultaneously

Three axes:
Sidebending: Opposite rotation around two vertical axes
1. One through body of the sphenoid
2. One through the center of the foramen magnum
Rotation: Rotate same direction around one AP axis to side of convexity (moves relatively inferior)
3. One AP axis from nasion to opisthion

Named for the side of convexity, side that moves inferiorly

Question 38

Vault Contact

Answer 38

For diagnosis and treatment
Physician places hands on either side of the cranium
Thumbs: slightly touching each other, just above sagittal suture, not touching the patient’s head
Index fingers: contact greater wings of sphenoid
Middle fingers: contact temporal and parietal bones in front of the ear
Ring fingers: contact temporal and parietal bones behind the ear
Pinky fingers: contacts the occiput, near occipitomastoid suture

Question 39

Fronto-occipital Contact

Answer 39

For diagnosis and treatment

Physician places one hand under the patient’s head, gently cupping the occipital squama

The other hand is placed across the forehead so that the thumb and middle finger of the hand contacts the greater wings laterally
- Or middle finger on metopic suture, and other fingers spread out along frontal