Dural Torque, Dentate Ligament or Cord Distortion Theory (Dr. Hollandsworth PPT)
Terms in this set (...)
other names for Dural Torque?
aka. Dentate Ligament or Cord Distortion Theory
Dural Torque Theory:
=any reference to the CSF or the meninges can fall into dural torque theory 1. Meninges= Dura mater, Arachnoid mater, & pia mater, 2. CSF= surrounds the CNS, brain & spinal cord
two componets of the Dural Torque theory?
1. Dentate Ligament, 2. CSF
=a band of fibrous pia mater extending along the spinal cord on each side between the dorsal and ventral roots—also called denticulate ligament.
CSF component of Dural torque- part 1:
= improper circulation of the cerebrospinal fluid aka. CSF has been suggested as a mechanism amendable to manipulation
CSF component of Dural torque- part 2:
=this speculative rational suggests that a condition of CSF stasis of aberrant flow leads to decrease nutritional supply to those CNS components bathed by the fluid
History of Dural torque theory:
1. Initially this was an upper cervical model, 2. Myelopathy like signs & symptoms can be present, Note: BJ. Palmer said: "No vertebral subluxation can exist below axis: therefore no adjustment with and direct intention or design could be given below an axis, to get sick people well."
Dentate ligament or Cord distortion Hypothesis:
Offers a mechanism whereby the effects of misalignments of the upper cervical vertebrae, via the dentate ligaments, produce mechanical distortions of the spinal cord.
1988 Grostic's paper:
=two mechanisms which dentate ligament adversely influence the conduction of neural impulses in spinal cord: 1. Direct mechanical irritation via dentate ligament traction, 2. Venous occlusion and local blood stasis & ischemia
What happens to the cord with movement or subluxation?
1. approximately 30 mm change in cervical spinal canal length from full extension to full flexion, 2. average of 3 mm lateral displacement between skull & atlas of 3 degrees produces an approx. 3 mm lateral displacement of the atlas, 3. approx. 23% of total width of spinal cord in upper cervical region which = approx. 13 mm
Could cord distraction produce a conduction block?
Jarzem et all. reported decreased spinal cord blood flow and concurrent interruption of somatosensory evoked potentials after experimental cord distraction
Cases of Upper Cervical Dentate Ligament strength:
1. mechanical strength & immobilizing character, 2. Emery relates numerous cases of perinatal necropsy that demonstrated fatal kinking of the medulla-spinal cord junction in hydrocephalic children because of the interaction of freely moveable brainstem and a fixed upper cervical cord= fixed through strong dentate ligament attachments
Dural Torque Key Words for Boards
Dural Torque Theory: causative agent of mechanical distortions in spinal cord as well as venous occlusion and local blood stasis & ischemia
Dural Torque Theory: responsible for formation of denticulate ligaments that can cause
Dural Torque Theory: outer covering that can get torqued by the increased tension in the denticulate ligaments
Dural Torque Theory: loss of flow of this results in lack of proper nutrition to the structures being nourished by the CSF
Aka's for Dural torque?
Dural Torque Theory is aka. Dentate Ligament Theory or Cord Distortion Theory
Upper cervical compromise TQ?
Dentate ligament, Pia mater, Dura mater, CSF all potential answers for TQ mentioning upper cervical compromise when don't have Myelopathy, cord compression, compressive myelopathy not answer choices