Neurophysiology of Learning Disorders and Developmental Dysfunctions

Neurophysiology, Learning Disorders, Developmental / Neurobehavioral Dysfunctions

Learning disorders, developmental dysfunctions, and childhood psychological diagnosis are the fastest growing problems facing parents today. Therefore, there has been an increase in the demands on chiropractic physicians to give parents treatment and management options without the use of medication.

Learning Disorders: Tricky to Diagnose Correctly

In the spectrum of learning disorders as well as psychological problems, there is often no diagnostic (anatomic or physiologic) evidence, (i.e. MRI, CT) that will identify the problem in the brain.

However, these are very definitively brain-based problems, with involvement of specific areas, termed 'functional' problems and may be caused by under-activity or lack of development in certain neurological pathways.

As a result, the child will often display corresponding changes in neurologic function. For example:

• They may have changes in sensory function, such as intolerance to many environmental stimuli.

• Children may also experience changes in motor function, and/or un-coordination in their ocular, gross motor, or fine motor abilities.

• Other changes may also be present, such as changes in the balance centers (vestibular) and the areas that control muscle tone.

• Changes in other functions, such as digestion and respiration.

By addressing the changes in neurologic function, by rehabilitating dysfunctional pathways through appropriate therapies we can positively affect the function of the brain.

Historically, the brain has often been described as a static organ system. Within the past ten to fifteen years, much of what we previously knew about the brain has changed.

• The current accepted view is that the brain functions more like a muscle, changing very dynamically in not only months or weeks, but literally at the speed of light.

• The cellular metabolic activity of the brain -- or its frequency of firing -- determines much of our cognitive, emotional and higher conscious thought.

• The functional unit of brain activity is the neuron. The primary functional activity of neurons is to survive by firing to other neurons and through gene coding expression.

• Neurons need two things to survive: fuel and activation.

  • Fuel is oxygen and glucose;

  • Activation is stimulation from the environment, (i.e. light, sound, touch, taste, smell, and sense of position (proprioception).

  • Changes in either fuel or activation affects the neurons of the brain, making them more fatigable -- decreasing function or causing spontaneous firing.

  • Factors that affect fuel delivery would be birth anoxia, dietary problems, and breathing difficulties.

On the topic of activation, we know that the environment influences our brain, and is brought into the brain by receptors:

• Light receptors in the eyes

• Sound in the ears

• Taste in the mouth

• Smell in the nose

• Touch in the skin

• Propioception, or sense of position

Propioception: The Sixth Sense

Propioception is the sense that we are least aware of but that has the most powerful influence because it is constant.

Proprioceptive receptors are found most in the muscles and joints of the spine, specifically of the cervical spine. Propioception and spinal attitudes are a reflection of the cortical activity of the child. That is why we see such profound postural changes in children with Propioception problems.

From the receptor the stimulus is relayed to thalamus, and then to other brain areas (except smell.) Propioceptive afferents not only project to the thalamus, but also relay to the cerebellum, then onto higher functioning areas of the brain.

A Brief Look at the Brain

The brain itself is made of several key areas, as follows:

• Cortex (subdivided into lobes)
  • Frontal
  • Parietal
  • Temporal
  • Occipital
• Cerebellum
• Basal Ganglia
• Brain stem
• Thalamus
  
  

Frontal Lobe: The Center for Learning, Emotions and Social Behavior

The frontal lobe is subdivided into four main functional areas; we will cover this in general.

In examining the function of the frontal cortex, it appears that each side of the frontal cortex is responsible for certain characteristic functions.
For example:

• The left frontal cortex is primarily responsible for:

  • Positive emotions

  • Language skills

  • Math skills

  • Reading

  • Approach behavior

  Left frontal cortical decreases will cause dyslexia, language problems, depression, etc.
  

• The right frontal cortex seems to associated with:

  • Negative emotions

  • Nonverbal communication

  • Attention and concentration

  • New learning

  • Timing

  • Withdrawal behavior
     

In general right frontal cortical problems can be associated with attentional and autistic spectrum behaviors. Loss of normal right side function causes:

• Loss of attention

• Inability to interpret social cues and emotions

• A lack of fear

• Motor planning problems

• Lack of boundaries, etc.
   

Specifically, in the children we treat, we see lack of development, or underactivity in neurons centrally in this area of the brain.

While some children do not all fit these models exactly, this is the generally accepted view of spectrum disorders.

Basal Ganglia: Motor and Emotion Control Centerr

Subsequently, the frontal cortex fires into the basal ganglia, which is a floodgate for motor and emotional activity.

The basal ganglia is comprised of several relay nuclei that facilitate these functions. When the frontal areas decrease their bombardment of the basal ganglia, the neurons in these areas are subsequently affected.

Functional problems in the basal ganglia are associated with motion-related disorders, such as:

• Tourette's Syndrome

• Tics

• OCD

• Hemiballismus - an involuntary flinging motions of the extremities

The basal ganglia symptoms subsequently become part of the spectrum of signs that the child may present with.

Cerebellum: The Brain's Communicator and Coordinator

The cerebellum is another functional area that is of concern. The primary functions of the cerebellum include:

• Receives incoming afferent feedback from muscles and joints and project to the contralateral brain.

• Works to smooth out motor functions descending from the cortex out to the soma.

• Involved with learning by working with the contralateral frontal cortex for learned cognitive thought.

• Involved with the vestibular or balance functions by controlling posture in a gravitational field and matching that with eye, head and body control.
  

Lesions in the cerebellum can be causal factors in:

• Hypotonia - causes low muscle tone (the amount of tension or resistance to movement in a muscle)

• Motion sickness

• Eye movement breakdown

• Gross motor dysfunction
  

What Causes these Developmental Problems?

The causes of these problems are multi-factorial. Obviously there are arguments pitting genetics versus environment. We accept theories from both arenas.

Typically, there are certain patterns in the medical history of the mother and the child that appear to be consistent. Many times the patterns are set forth even before the child is born.

• Maternal stresses have been identified as causative factors to hormonal changes in brain development. Birth trauma or anoxia at birth is common.

• Early ear infections and colic are common presentationss, as well as poor vaccine reactions and multiple antibiotic rounds.

• Early history of motor delay in the body, or the eyes is common.

• Gastrointestinal dysfunction, skin problems, changes in tone, the list goes on.
   

Another factor is diet and activity of the child. Many speculate that the rise in attentional problems mirrors that of the rise in obesity in children, that they are less active and do not provide enough stimulus to the brain.

Brainchild: Correcting Neurological Problems

To sum it all up, it is clear that many of the problems facing children are of a neurologic origin. Although the outward appearance may be behavioral or a learning problem, the underlying dysfunction is in the nervous system.

At Brainchild Achievement Center, we focus on rehabilitating these problems.

• We will take a comprehensive history of your child to identify any causative factors.

• The goal is to identify and localize the child’s current function based on their neurologic exam, remove causative factors and start to rehabilitate them.

• We develop an individualized treatment program for each child to specifically affect hypo-functioning areas of the nervous system, using feedback from muscles and joints, vestibular influences, eye movements and gross motor movements.
  
  

For information about childrens' neurological conditions we treat, read Help Kids Behave & Learn.
 

For more information about our treatment programs, take an in-depth look at Brainchild Program: A Novel Approach to Childhood Neurological Disorders.