Download File

INVOLUNTARY MOTION
STUDIES
A summary for study group
by David Such
Contents
1.
2.
3.
4.
5.
Review of anatomy and physiology
The craniosacral concept
Palpating the cranial rhythm / involuntary motion
Pattern testing
Treatment
1. Review of anatomy & physiology
A review of:
Osteology of the cranium
Meninges
Dural partitions / membranes
The ventricular system
Cerebrospinal fluid
Venous sinuses
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
Anterior view of the skull
Lateral view of the skull
Inferior view of the skull
Meninges
The meninges are three layers of membranes
which surround the brain and SC
1.
Dura mater – tough, thick external fibrous
layer
2.
Arachnoid mater – intermediate, delicate
layer
3.
Pia mater – innermost area, firmly attached
to the surface of the brain
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
Meninges: the layers
Meninges: a closer look
•
Dura mater
–
•
Arachnoid mater
–
•
Surrounds the brain, but does not enter the sulci or fissures
Pia mater
–
•
Thick, dense, fibrous membrane. Cranial DM has two parts:
1.
Outer periosteal – formed by the periosteum covering the internal surface
of the cranial bones, esp @ the sutures, cranial base and foramen magnum
2.
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
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
Meninges: innervation
Innervation is
from:
1. All three
branches
of CN V
2. CN X
3. Spinal
nerves C1C3
4. & possibly
from CN’s
IX & XII
Meninges: innervation
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.
Dural partitions

Falx cerebri


Tentorium cerebelli


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
Falx cerebelli


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 crista galli of the ethmoid bone. Posteriorly it
attaches and blends with the tentorium cerebelli
Separates the two halves of the cerebellum. Superiorly it is attached to
the tentorium cerebelli, whilst posteriorly it attaches to the internal
occipital crest of the occiput
Diaphragma sellae

A small horizontal shelf that covers the hypophyseal fossa in the sella
turcica of the sphenoid bone. The infundibilum passes through this
membrane, connecting to the pituitary gland
Dural partitions
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
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
The ventricular system
Cerebrospinal fluid
CSF is a clear, colourless, cell-free fluid that
circulates through the ventricles &
subarachnoid space that surrounds the brain
and SC
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
CSF: secretion & absorption
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.
CSF: circulation
CSF: circulation
1. Formed in the choroid plexuses of the paired lateral
ventricles
2. Flows into the third ventricle through the
intervertebral formania
3. More CSF is added by the choroid plexus in the roof
of the third ventricle
4. Flows through the cerebral aqueduct, passing
through the midbrain, into the fourth ventricle
5. More CSF produced here as well
6. CSF then enters the subarachnoid space via the
median and lateral apertures, and the SC by the
central canal
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
Venous sinuses: the main ones
1. Superior
sagittal
sinus
2. Inferior
sagittal
sinus
3. Straight
sinus
4. Transvers
e sinus
5. Sigmoid
sinus
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:
1.
Sup sagittal sinus
Sup border of falx cerebri; sagittal sulcus of frontal bone
2.
Inf sagittal sinus
Inf margin of falx cerebri
3.
Straight sinus
Continues posteriorly along the junction between the falx cerebri and
tentorium cerebelli to reach the confluence of sinuses
4.
Transverse sinus
Passes laterally from the confluence of sinuses forming a groove in the occipital
bones
5.
Sigmoid sinus
A continuation of the above, marks ‘s-shaped’ grooves in temporal & occipital
bones of post cranial fossa – becomes IJV
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
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
2. The craniosacral concept
The craniosacral concept
Primary respiratory mechanism
Reciprocal tension membranes
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)
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:
1.
2.
3.
4.
5.

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
Reciprocal tension membranes


The cranial term for
the dural membranes
They are the:





Falx cerebri
Falx cerebelli
Tentorium cerebelli
Diaphragma sellae
They are continusuly
under dynamic
tension so that
change in one
requires adaptive
change in another
(Chaitow, 2005, p.4)
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)
3. Palpating the cranial rhythm
Flexion & extension phases
Flexion & extension at the cranium
Flexion & extension at the sacrum
Hand holds
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
Flexion & extension at the cranium
Transverse widening
AP shortening
Vertical shortening
Transverse narrowing
AP lengthening
Vertical lengthening
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

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
interthenar sulcus. The sacral
spine should then lie between
the third and fourth fingers

(Upledger & Vredevoogd, 1983, p.
34)
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
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
Flexion / extension
Torsion
Side bending & rotation
Non-physiological



Vertical displacement
Lateral displacement
Compression
Vertical displacement
Lateral displacement
Compression
5. Treatment
Balanced Membranous Tension
CV4
Balanced Membranous Tension (BMT)

‘Balanced Tension’


“The most ‘neutral’ position possible under the influence
of all the factors responsible for the existing pattern – all
attendant tensions having been reduced to the absolute
minimum” (Magoun, 1976)
BMT
Identify the strain pattern at the SBS (eg. left torsion with
right side bending and vertical displacement)
 Find by palpation, the ‘middle’ point – position of ease
 Bring the fluid fluctuation to a ‘still point’
 Re-palpate cranial rhythm to check for re-establishment of
normal motion

CV4


Palpate a couple of cycle of motion first
Hand position for CV4


Thenar eminences medial to the occipitomastoid sutures
Restrain rather than compress fluid fluctuation
Gently ‘hold back’ during flexion phase, increasing this
over approx 3 cycles
 Wait at the still point – don’t let go!



Let the normal wave of involuntary motion resume –
gradually easing off the restraint over approx 3 cycles
Re-assess via cradle hold