The Sensitive Nervous System Chapter VI: Clinicians and Their Decisions

This is a summary of Chapter VI of “The Sensitive Nervous System” by David Butler. Intro All approaches (Maitland, Mckenzie, Mulligan) have myths. The common bond between them all is pain. Today we will look at building a clinical framework with pain as the cornerstone. Evidence-Based Medicine (EBM) EBM is defined as a conscientious, explicit, and judicious use of current best evidence in making patient care decisions. This concept is not merely reading researches articles, but it combines scientific evidence and clinical expertise. You have to know when to apply what. For manual therapists everywhere, this creates issues and unease. 1)      Decision making moves toward an external body. 2)      Evidence suggests manual therapy improvements are more psychosocial than physical. 3)      A disconnect between researcher and clinician. The researcher thinks: “What does this work contribute to the literature?” The clinician thinks: “What does this work do for my patient?” The movement towards outcome-based therapy per EBM is also problematic for several reasons. 1)      Clinicians begin to think statistical analysis becomes greater than any other form of knowledge rather than complimentary. 2)      Research doesn’t take into account the inherent uncertainty and subjectivity in a clinical encounter. 3)      Good evidence can lead to bad practice if applied in uncaring and unappealing environments. 4)      Outcomes may be coming out too quickly, leading to research development stopping in certain areas. Butler’s thoughts are summed up very nicely when he states it would be a sad day if meta-analyses have the final say instead of exposing

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The Sensitive Nervous System Chapter V: Neurodynamics

This is a summary of Chapter V of “The Sensitive Nervous System” by David Butler. Intro Neurodynamics is the study and relationship of nervous system mechanics and physiology. The testing protocols for neurodynamics assess the nervous system’s ability to lengthen, glide, and change amongst interfacing structures. When discussing neurodynamics, it is important to think of the nervous system as a continuum. Mechanical, electrical, and chemical changes in one part of the nervous system affect other related parts. Gross Movements and Dynamics When having a nervous system, the following qualities, movements, and buffering capabilities are necessary: Slide, glide, strain. Elongate (think gymnasts) and return from elongated position. Compress (ulnar nerve during elbow flexion). Stength (kicking a field goal). Jolting (whiplash). Repetitive forces Bending Fluid/chemical selectivity. Neural Connective Tissue These include the meninges, nerve root complex, and peripheral nerve structures. Broken down as follows: Meninges Dura mater (outer, tougher) Arachnoid mater Pia mater (inner, thinner) Nerve root complex Root Sleeve Dorsal and ventral roots DRG Spinal nerve. Peripheral nerves Epineurium Perineurium Endoneurium Mesoneurium – Sheath that surrounds a nerve. Contracts like an accordion to glide along adjacent tissues. Can become fibrotic with injury. Important Attachments Meningovertebral ligaments – anchor down to spinal canal, which could become symptomatic. Rectus capitus posterior is connected to the dura mater between the occiput and atlas; helping the dura fold. Makes you wonder what you are truly doing when you release this structure. The sympathetic trunk’s proximity to the spinal column makes it susceptible to increased loads

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The Sensitive Nervous System Chapter IV: Central Sensitivity, Response, and Homeostatic Systems

This is a summary of Chapter IV of David Butler’s “The Sensitive Nervous System.” Intro Central sensitization is a phenomenon that occurs in the dorsal horn, which can be best described via 4 different states: 1)      Normal: Inputs = outputs; innocuous sensations are perceived as such. 2)      Suppressed: Inputs that would hurt do not; think an athlete who injures himself but finishes the game. 3)      Increased sensitivity: Pain system has lower activation threshold, leading to pain spreading and pain with light touch and gentle movement. This change occurs because A beta fibers begin taking over C fiber locations in the dorsal horn. 4)      Maintained afferent barrage, CNS influences, and morphological changes: Long lasting changes in the dorsal horn from a persistent driver, such as… A fiber phenotype changes. Persistent DRG discharge. Persistent inflammation. Supraspinal influences Gene transcription change in dorsal horn neurons. Inflamed dorsal horn or DRG Maladaptive beliefs, fears, and attitudes. Dorsal horn sprouting; A Beta fibers take over C fiber space. Persistent glutamate activity. Descending Control The CNS has an endogenous pain control system which activates during injury threat, noxious cutaneous input, or expectations and learning. Such an example of this is when you go to a healthcare practitioner’s office and no longer hurt. Another example of when this system is activated is during aggressive manual therapy. Think about how good your body may feel after sustained pressure or even a needle to a trigger point. Central Sensitization Patterns Areas/descriptors Symptoms not in neat anatomical/dermatomal boundaries. Original pain

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The Sensitive Nervous System Chapter III: Pain Mechanisms and Peripheral Sensitivity

This is a summary of Chapter III of “The Sensitive Nervous System” by David Butler. Intro When we discuss peripheral issues, we are not only talking about the pathoanatomical source, but pathobiological processes dominating the clinical picture. There are several instances in which the pathoanatomical model falls short: Phantom limb pain. Why pain persists post-healing. Why similar injuries heal faster in certain people. Why 10-14% of the world’s population have an ongoing pain state. Tissues do get injured, but we must not forget the nervous system’s intricate link to injury. When tissues are hurt, they repair but are unlikely to ever be the same again. To protect against further threat, the CNS has the ability to increase nerve sensitivity. This change happens only if the person decides consciously or subconsciously that there is a need for it, and does not occur in everyone. There are two ways in which this sensitivity develops; Primary sensitivity: Increased sensitivity to input at the injury site. Secondary sensitivity: Increased sensitivity to uninjured tissues around the injury. All pain is neurogenic, operates in a continuum, and has many components. Nociception (NOC) NOC is tissue pain that occurs at a neuron’s end that is excited by mechanical, thermal, or chemical stimuli. It does not always match up with tissue health status. A normal nerve ending has a very high firing threshold, and nearly 1/3 will never fire. These are called silent nociceptors. Looking at a chemical process such as inflammation shows us how these nerves fire. 

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The Sensitive Nervous System Chapter II: A Bird’s Eye View of the Nervous System

This is Chapter II summary of “The Sensitive Nervous System.” Intro Here we develop a framework for understanding the nervous system with pain as the centerpiece. The nervous system is very much misunderstood as an input/output system: Myth: Input/output system. Reality: The nervous system is an active activity constructor. It evolves and learns rather than computes. It is    also widely distributed without a master neuron pool for a particular sensation. The nervous system is made up of two components, hardware and wetware. The Hardware Neurons make up the hardware. These components respond and keep a chemical history of many different inputs and outputs. This is true for each individual neuron, which allows each one to be ready to go when called upon. This hardware is one time when the part actual does equal the whole, as one neuron’s activity resembles the entire Central Nervous System’s (CNS) behavior. The nervous system’s size is near-astronomical. There are approximately 100 billion neurons with 1014 synapses. This figure only factors in the functionally known nervous system components. If we throw in 103 nodes/centers (connected by 105 pathways) and the 10:1 glial cell:neuron ratio, and we have an incredibly dense system in place. A pinhead speck of brain tissue has 350 million connections. This hardware is also very redundant, as very few neurons go straight from sensory organ to cortex.  There are several feedback loops in place which allows for constant checking and rechecking. The Wetware Wetware includes the different neurotransmitters and neuromodulators. Examples

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