Overview of Functional Neurology

Neurology and the neurological examination are traditionally taught using a disease-orientated model.  While this approach may help to detect the presence of many neurological disorders, it may be less sensitive for investigating and estimating the physiological integrity of the nervous system associated with the majority of neurological symptoms.

The clinical interventions utilized in functional neurology have been derived from the integration and application of many of the theoretical concepts of a vast array of basic and biomedical sciences, including embryology, psychology, neuropsychology, neurology, neuroanatomy, cellular biochemistry, neurophysiology and genetics. Functional neurology may, therefore, be viewed as a concept that emphasizes the neuron and the nervous system as being the modulator of human expression and experience.  The unique and complex response of each individual’s nervous system to changes in their environment may provide insight into the neuronal health and output at multiple levels of the neuraxis.  

The original concepts of this approach to treatment were developed by my friend and mentor Professor Frederick Carrick, of the Carrick Institute for Professional Studies in Florida. Prof. Carrick’s original ideas have evolved as he has gained a deeper understanding of how the neuraxis functions and on the knowledge gained from clinical experience into their present form, which is taught by the Carrick Institute.

Investigations involving functional neurological applications have been published in myriads of journals that span the disciplines listed above and make it extremely difficult to establish an overview of the vast array of material that comprise the state of functional neurology today in a single article such as this one.
It has become quite clear that functional neurology has numerous diverse and widespread applications in the restoration and maintenance of health in the human population.

It may seem quite amazing that the interventions, ranging from simple to complex, utilized in the application of functional neurology are engineered to address three basic fundamental activities present and necessary in all neurons.

These activities include:

1. Adequate gaseous exchange, namely oxygen and carbon dioxide exchange. This includes blood flow and anoxic and ischemic conditions that may arise from inadequate blood supply;
2. Adequate nutritional supply including glucose, and a variety of necessary cofactors and essential compounds;
3. Adequate and appropriate stimulation in the form of neurological communication, including both inhibition and activation of neurons via synaptic activation.

Synaptic activation of a neuron results in the stimulation and production of immediate early genes and second messengers within the neuron that stimulate DNA transcription of appropriate genes and the eventual production of necessary cellular components such as proteins and neurotransmitters.

The investigation and determination of how well neurons are performing these three basic activities and how to alter these activities, if inappropriate or inadequate, comprise the fantastic clinical journey that is functional neurology.

In the quest to answer the aforementioned questions, the functional neurologist may enlist the help of a variety of complex and sophisticated testing equipment, including neuropsychological testing instruments, objective muscle strength testing instruments, somtosensory evoked potentials, visual evoked potentials, qEEG, visual kinetic tracking, nystagmography or visuomotor testing, computerized balance platforms, MRI and PET scans, or tests as simple as looking at pupil reactions to light, bilateral blood pressure or temperature differentials of the forehead or peripheral limbs.

It is essential that the practitioner perform a complete and thorough physical examination in which different areas of the neuraxis are tested and challenged at the appropriate level. The practitioner must also strive to understand the meaning of the results obtained from a neurological and functional perspective. The level of response obtained during the physical examination is often used to assess the level of activity in a certain area of the neuraxis and to later gauge the effectiveness of treatment.

It is not until we start to examine the three fundamental activities of the neuron in detail that we begin to realize their importance to the neuron and, hence, nervous system function in both health and pathological states. Mild alterations from optimum in any of these activities may result in dysfunction of whole systems in the neuraxis, such as the altered movement states in Parkinson’s and Huntington’s diseases due to imbalances of stimulatory or inhibitory thalamic activation respectively.

A variety of conditions or states may also arise when afferent stimulation or inhibition is aberrantly distributed asymmetrically to the cortex, resulting in functional hemispheric imbalance which may result or contribute to a variety of learning disabilities, attention deficit disorders, affective and emotional disorders, and central autonomic dysfunctional conditions, including the complex regional pain syndromes and dysautonomia.

It is also becoming apparent in recent years that the functional state of the neuraxis and the functional immune state of an individual are closely interconnected, and states of hemispheric imbalances can result in immune system dysfunction such as systemic inflammatory or autoimmune reactive states.

Correcting functional neurological imbalance requires an extensive knowledge of neuroanatomy and neurophysiology in an attempt to understand the central integrative state of the neuraxis. An understanding of the central integrative state of different areas of the neuraxis is obtained by a variety of testing procedures and observations of gateways to the neuraxis, such as the activity of cranial nerves, reflex activity of muscles, and tonic activation levels or responses to stimuli of the autonomic nervous system.

Intact afferent pathways are identified which, when stimulated or inhibited, will result in the appropriate stimulation reaching a target area in the neuraxis. Stimulation of these pathways is then utilized in restoring the functional state of the area.

Consideration of the current metabolic state of the target area must be considered and monitored as the intervention is instituted and as it progresses so that no damage occurs as a result of over stimulation, which may result in free radical formation and ultimately neuronal necrosis.

External forms of afferent stimulus may be utilized to stimulate the neuraxis including all of the sensory modalities, i.e., visual, auditory, taste, pain, etc., manipulation, vestibular stimulation, and reflex (spinocerebellar) stimulation.

Internal forms of stimulus include mental function and memory exercises.

Chiropractors are well placed to understand and apply the concepts of functional neurology due to their undergraduate and postgraduate education and their clinical experience in the application of afferent stimuli such as manipulation.

Although the shear volume of material that needs to be assimilated in order to begin clinically applying functional neurology may seem daunting to the student or practitioner at first glance, the journey is filled with discovery and excitement as the workings of the neuraxis unfold. The clinical results are often dramatic and immediate which, above all, has inspired many a practitioner to embark on this lifelong adventure of enlightenment and learning.

Randy Beck, B.Sc., D.C., Ph.D., is a graduate of Canadian Memorial Chiropractic College. He has completed postgraduate studies in Psychology, Immunology and Neurology. He is presently involved in a number of international research projects and is co-authoring a textbook on Functional Neurology. He was formerly the Dean of Chiropractic and Basic sciences and Director of Research at the New Zealand College of Chiropractic. Presently, he practices Chiropractic Functional Neurology at the Papakura Neurology Center and The Maungakiekie Clinic located in Auckland, New Zealand.

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