Cranial Field (Curtis) Flashcards
History
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
Osteopathy in the Cranial Field
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
Primary Respiratory Mechanism
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
5 Phenomena
of the respiratory mechanism
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
Fluctuation of CSF
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
Inherent Rhythmic Motion of CNS
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):
- A pulsation synchronous with cardiac contractions
- A pulsation coinciding with thoracic respiration
- A wave of constant rate not related to either
- An undulating pulsation not related to either
Mobility of Intracranial and Intraspinal Membranes
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
Dura mater:
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
Dura mater reduplications:
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
Dura mater attachments and surrounds
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
Reciprocal Tension Membrane
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
Articular Mobility of Cranial Bones
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
Involuntary Mobility of Sacrum Between Ilia
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
anatomy
make sure to look at the slides for an anatomy review
Venous Sinuses- general
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
venous sinuses- specific
Superior sagittal sinus
Inferior sagittal sinus
Straight sinus
Occipital sinus:
Transverse sinuses:
Sigmoid sinuses:
Superior sagittal sinus:
Attached portion of the falx cerebri
Drains to R transverse sinus/ confluence of sinuses
Inferior sagittal sinus
Free border of falx cerebri
Drains to straight sinus
Straight sinus
Lies in junction of falx cerebri and tentorium cerebelli
Drains to L transverse sinus/ confluence of sinuses
Occipital sinus
Lies in attached portion of falx cerebelli
Drains to L transverse sinus
Transverse sinuses:
Lie in attached border of the tent from confluence of sinuses to the parietal angle
Drains into sigmoid sinuses
Sigmoid sinuses:
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
95% of venous blood from cranium drains into
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
midline (unpaired) bones of the cranium. How do they move?
Vomer Ethmoid (median plate) Sphenoid Occiput \+ Sacrum
Move through flexion and extension around a transverse axis
Bilateral (Paired)
bones of the cranium. How do they move?
Mandible* Maxillae Zygomae Palatines Nasals Lacrimals Frontal* Temporals Parietals Ethmoid (lateral mass) Move through external and internal rotation
- act as paired bones
SBS
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
Physiologic Motion
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
Physiologic Strain Patterns- general
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
Primary Respiratory Mechanism:2 Phases
Flexion and Extension
things associated with Flexion
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
things associated with Extension
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
description of flexion
Rotational motion around 2 transverse axes
- Occiput: Directly superior to foramen magnum
- 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
description of extension
Rotational motion around 2 transverse axes
- Occiput: Directly superior to foramen magnum
- 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
Types of physiologic strain patterns
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
bert and ernie in phyiologic strain patterns
Flexion
Forehead wide and sloping
Prominent eyes
Protruding ears
Extension:
Forehead vertical
Receded eyes
Ears close to head
Torsion
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
Sidebending Rotation
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
Vault Contact
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
Fronto-occipital Contact
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
