School-Related Medical Issues Archive 2013
John L. Digges, MD, PhD, MPH, FAAP
Dr. Digges practiced general and behavioral pediatrics in Oklahoma and California for 14 years. For ten of the past 12 years, he has served as the Forensic (Child Abuse) Pediatrician for Kern County, California; and he has had a private practice limited to ADHD consultations for the past 12 years. He has been a CME surveyor for the Institute of Medical Quality (CMA) since 2000, and is a recent past-President of the Kern County Medical Society. Dr. Digges has been at the DCN since August, 2008.
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We have a student taking PE who has been diagnosed with Charcot-Marie-Tooth disease. He is doing quite well now, ambulatory and not in a lot of pain. He is concerned that he is too thin and wants to exercise to "bulk up". Are there any problems to be anticipated if he were to begin weight training at school?
Uncertain PE Teacher
Palo Alto, CA
Thank you for your question concerning this often under recognized condition. Charcot-Marie-Tooth (CMT) disease (aka hereditary motor and sensory neuropathy- HMSN) is a genetic condition which affects peripheral nerves (i.e. involving legs, arms, feet and hands) and occurs in about 1/2500 live births. The axon or long thin portion of the neuron is typically ensheathed in a material called myelin, that greatly increases the speed with which electrical signals travel from one neuron to the next. CMT results when various gene mutations interfere with the production of proteins which control the structure and function of either the axon itself or the myelin coating the axon. The degeneration of either the myelin or the peripheral axon itself results in markedly reduced nerve conduction velocity, which (for sensory nerves) can manifest as decreased perception of heat, cold and pain; and (for motor nerves) can cause muscle weakness and decreased muscle mass.
Onset of symptoms typically occurs from mid-childhood to early adulthood, with more severe cases often presenting at a younger age. Symptoms presenting initially include problems with maintaining balance, increased clumsiness, and decreasing strength in the muscles of the feet. Consequently, children with CMT often display problems with running and may have a high arched foot, a flat foot, or one or more curled toes (hammer toes). Due to weakness in the ankles, these children are more likely to experience ankle sprains or falls, and may require orthotic devices to support their ankles.
Progressive loss of muscle mass in the lower legs gives the appearance of “stork legs,” or an “inverted champagne bottle.” “Foot drop,” the inability to lift the foot or hold the foot in the horizontal plane, occurs due to the developing weakness, and may result in frequent tripping. In order to compensate, children with CMT may raise their knees high (muscles closer to the core are typically less severely affected than muscles farther away from the core), resulting in a characteristic “steppage” gait.
As the sense of touch gradually diminishes, the inability to detect temperature changes may place the child at risk of injury to the feet and hands from cuts, blisters or burns. As nerve function continues to decline, the child may experience sensations of tingling or burning in their hands and feet. Gradual loss of motor function in the hands may cause problems with holding a pen or pencil, buttoning buttons, pulling a zipper or turning a doorknob.
Your student appears to have symptoms on the milder end of the spectrum, as he is still able to ambulate without assistance and is not experiencing pain. Unfortunately, due to the progressive nature of CMT, his symptoms are expected to increase gradually over time. Although the literature with respect to exercise and CMT is not huge, it does suggest some “take-home” points.
First, physical exercise in patients with CMT appears to help preserve performance and slow the rate of functional decline. A study from 2004 showed improvements is strength and function in response to resistance training, while another study published the same year showed that resistance training helped increase strength and improve performance of activities of daily living. A small study from 2011 suggested that interval training in patients with CMT resulted in improved heart rate variability.
A study from 2003 found that the dominant hand was weaker in 106 outpatients with CMT, and the authors hypothesized this might represent overuse weakness. More recent studies have generally failed to find support for the hypothesis, with the exception that there was a mild degree of dominant hand weakness noted in more seriously affected older patients. The current evidence suggests that there is not enough data in support of this hypothesis to warrant limiting hand use as a strategy to prevent hand weakness in later years.
With respect to his desire to “bulk up,” it appears that time is on the side of weight gain for individuals with CMT. Due to restricted mobility issues with increasing age and progression of CMT symptoms, most patients were more concerned about losing weight rather than gaining weight. For him, it may be prudent to recommend that he and his family contact the CMT Center of Excellence at Stanford University. They could then discuss their concerns with experts, and get referred to the appropriate physical therapist or occupational therapist with the primary goals of improving and preserving muscle function. If specific exercises to promote muscle growth appear to be warranted and safe for him, these could be implemented by skilled practitioners in the relevant fields and then integrated into his PE program at school.
Thank you again for your question and I hope this is helpful for you.
John L. Digges, MD, PhD, FAAP
Diagnostic Center North, Fremont CA
Hello, we have a 2nd grade student at our school who experienced a near drowning incident as a young child (2-3yrs old) resulting in extended oxygen deprivation. He is experiencing significant difficulty retaining information, particularly site (sic) words and basic reading skills. Can you suggest any strategies to use when teaching reading to students with this kind of memory loss?
Cypress Elementary School
Thanks so much for your inquiry. Our pediatrician will address the medical portion of your question and our reading specialist will discuss strategies.
Children from 1-4 years of age comprise one of the two highest risk age groups for near drowning, which often occurs in bathtubs or swimming pools (males from age 15-25 years old constitute the other highest risk group, with the episodes typically occurring in natural bodies of water and involving alcohol consumption, drug use, and/or accidental injury). Near drowning is defined as survival following a primary respiratory impairment from submersion in a liquid medium which may result in life without morbidity, survival with a wide range of morbidity, or death occurring after some delay.
Near drowning interferes with oxygenation and may lead to damage of multiple organ systems; including the brain, nervous system, lungs and heart. Two of the most critical for our purposes are the lungs and the brain. Hypoxia damages lung tissue, decreasing the lungs’ ability to adequately oxygenate the remaining red blood cells in the circulation (producing hypoxemia). Insufficient availability of oxygen causes damage to the capillaries, which can lead to leakage of blood from the vessels into the extravascular space. This loss of fluid from the vascular space decreases the amount of blood remaining in circulation (hypovolemia), and may impair the perfusion of blood to tissues (ischemia).
In fresh water submersions, some red blood cells burst, and the remaining intact red blood cells become diluted. Ruptured red blood cells release potassium into the bloodstream, which can slow the heart rate or even stop the heart from beating.
Increasing acidity of the blood due to cell death may also contribute to decreased cardiac muscle contractility and decreased cardiac output. A poorly functioning pump makes the cardiovascular system even less efficient, and increases the likelihood of ischemia. With fewer red blood cells available to carry oxygen to tissues, the oxygen carrying capacity of the blood is reduced and inadequate amounts of oxygen reach the tissues (hypoxia). The term hypoxic-ischemic brain injury refers to brain damage resulting from a compromised cardiovascular system delivering inadequate amounts of insufficiently oxygenated blood to the various tissues and organs. Fortunately, some near drownings involve primarily hypoxia, with cardiac function remaining adequate.
The cerebral cortex, which controls the brain’s highest conscious functions, is the area of brain which appears to be the most sensitive to oxygen deprivation and subsequent hypoxic damage. After about 5 minutes of submersion, the brain may begin to suffer irreversible damage to some of its cells.
Brain is comprised of both gray matter and white matter. The gray matter consists of neuronal cell bodies, dendrites, some axons, glial cells and capillaries. White matter consists primarily of myelinated axon tracts with relatively few cell bodies. Gray matter is located at the surface of the cerebral cortices and cerebellum as well as deep in the brain substance (e.g. thalamus, hypothalamus and basal ganglia), cerebellum (deep cerebellar nuclei) and brainstem. White matter tracts function as the high speed communication system for the brain. Gray matter neurons are metabolically very active, and consume 95% of the oxygen delivered to the brain.
Hypoxia appears to preferentially damage the most metabolically active cells; specifically the deep gray matter nuclei, cerebral cortices, hippocampi, basal ganglia and cerebellum. These gray matter neurons are involved with decision making, impulse control, memory, speech, sensory perception, emotions and muscle control.
Generally, the extent of the damage to brain reflects the severity and duration of oxygen deprivation. However, when considering brain injury as a result of oxygen deprivation associated with emersion in water, one complicating variable is the temperature of the water. Very cold water (below 35-40 degrees F) results in less damage to brain than warm water. Water reduced to these temperatures in small children may induce the mammalian diving reflex; which causes respirations to cease, heart rate to slow considerably, and non-essential vascular beds to close so that blood flow is preserved preferentially for the heart and brain. Each of these factors reduces oxygen consumption and thereby offers some protection against cell death from hypoxia.
Brain injury in near drowning falls along a continuum from mild (full recovery possible) to severe (resulting in a persistent vegetative state). It has been observed that hypoxic brain injury in a toddler may appear as benign initially, but later become recognized as being much more pervasive than was originally thought. One interpretation is that some of the injury may occur to regions of the brain that are essential for the development of skills outside the range that is observed in 2-3 year olds. As the child ages, a new skill which is dependent upon an injured region of the brain may not develop, or may be quite delayed in developing. Fortunately, the human brain has the capacity for uninjured portions to be recruited to learn to perform the functions that the injured brain region would have performed. This capacity is referred to as neuroplasticity. Although it may be seen throughout the lifespan, it is most robust during the earliest years of brain development.
Although his limitations are going to be frustrating for your student, his family and his teachers, it should be noted that your student’s difficulties with reading and information retention place him along the relatively milder end of the near-drowning brain injury continuum. Although we do not have the specifics of his near drowning episode, his avoidance of a more devastating outcome may have resulted from the cumulative protective effects of such variables as his young age (optimal capacity for neuroplastic remodeling), possibly cold temperature of the water, relatively short emersion time, adequate cardiac output (i.e. absence of ischemia) and/or prompt and effective resuscitative efforts.
Elementary aged student with Seizure Disorder and Disruptive Behaviors
I am working with a student who has a complex seizure disorder, Lennox-Gastaut Syndrome. He is very difficult to work with, and often engages in various off-task and non-compliant behaviors. He is unable to particpate in most General Education Curriculum, and spends most of his time not following directions! We have tried many different behavior interventions, but nothing seems to work. He is not making educational progress and often forgets what has already been taught. What behavior interventions would you recommend?
Since a response to your question involves both educational and medical issues, an education specialist and a behavioral pediatrician have collaborated to provide an answer. Your student’s Lennox-Gastaut Syndrome can be expected to have a significant impact on his ability to learn. Further, the complexity of the condition explains why behavior interventions have not been more successful.
When considering the premise of behavior intervention, the key to success lies in the process of teaching a student how to not engage in one behavior while teaching them how to engage in a more appropriate behavior to replace that maladaptive behavior. However, in this student’s case, the set of behaviors that he displays are likely not always volitional behaviors (are not within his control). Consider the following factors when analyzing this student’s behaviors:
- Lennox Gastaut syndrome is characterized by having multiple types of seizure activity. This may include grand mal seizures, which consist of rhythmic, repetitive tonic and clonic contractions involving the entire body. Other seizure types resulting from abnormal electrical activity in the brain can present as blinking, repetititive jerky motor movements, smacking of the lips, various hand movements, staring spells, or experiencing feelings of tingling or numbness in the body.
- When the student is experiencing seizure activity, his brain is not processing information that is being presented to him. People who have seizures are typically amnestic (without memory) for events which were happening while the seizure activity was occurring.
- The student is likely having multiple seizures at night while he is sleeping, as is common with Lennox Gastaut Syndrome. In this case, the abnormal electrical activity would be expected to interfere with normal sleep and consequently could inhibit the process of memory consolidation. This results in “losing” the new information that had been learned during the previous day.
- Much of the behavior that the student is manifesting is likely related to his seizure disorder. While having seizures or abnormal electrical discharges in his brain, the student may appear to be either non-responsive or “ignoring” directives. At times, other seemingly “off task” behavior may be a manifestation of the abnormal electrical activity occurring in his brain.
In addition to seizures mimicking willfully non-compliant behaviors, the potential exists for prolonged recurring seizure activity to itself produce injury to brain neurons. Regardless of its source, brain injury may result in the student exhibiting problems with his:
- ability to inhibit actions/control impulses;
- ability to synthesize information, make decisions, and integrate information; (These difficulties can be anticipated when the injured brain includes the regions which are necessary for assessing a situation and deciding what is appropriate, recognizing what he should do/how he should react, and identifying what responses are appropriate.)
- ability to regulate his behavior.
Behavior interventions designed to target volitional behaviors will be ineffective in decreasing the incidence of non-volitional behaviors (resulting from his seizure disorder). Even the best reinforcement system or contingencies that may be highly motivating and meaningful would not be expected to alter his seizure-induced behaviors. Additionally, it will be difficult to determine a replacement behavior for those behaviors that are not under his control, and such efforts may be perceived by him as being punitive and unfair.
Notwithstanding this student’s medical condition, effective behavior interventions can be developed. Foremost, keep in mind:
- That compassion and empathy will be important when working with the student
- His performance will be inconsistent
- Progress and retention will be slow and unsteady
- Creating a meaningful and engaging curriculum that he can access will support more learning and less undesirable behavior!
- It is very difficult to distinguish between willful behavior and seizure-induced behaviors. Whenever possible, give the benefit of the doubt by repeating a directive or instruction and giving him another opportunity to comply.
- Being positive helps. Avoid scolding or telling the student what he hasn’t done correctly. Frame directives in a positive way so that he feels like staff and family believe he can do what is being asked.
- One step directions will lead to more success. Immediately provide praise (verbal, receiving a token/star/stamp) following the completion of the direction. Then proceed to giving the next step.
- Chunking activities and tasks into short time periods enhances his chance for success. This student will likely need to earn a reinforcement (task/toy/activity), even if for brief periods, every 10-15 minutes.
- Consider using a first/then board, coupled with tokens which can be earned frequently (every couple of minutes) to support his ability to successfully complete tasks.
- Earned tokens should not be taken away in response to lack of success. If he is struggling with completing the task, first consider if the task is meaningful, appropriate, and engaging. Then, remember that this student’s medical condition may unpredictably affect his ability to be present and engaged. Finally, continue to support him through the activity by providing positive prompting so that he ultimately experiences success.
- His inability to make his body do what he wants may frustrate him. When considering that frustration, recognize that behavior may also be his attempt to communicate when his body, speech, and brain are not cooperating. Listening to those attempts allows his teachers to provide him with a more appropriate way to get his needs met. This may be as simple as stating what you think he wants (i.e,” I think you are showing me that you don’t want to do this task”), getting a positive response from him (i.e., he says “yes”), and honoring that request when he makes it more appropriately.
We hope this is helpful, and thank you for writing.
Tara Zombres, M.Ed., Education Specialist
John L. Digges, M.D., Ph.D., Behavioral Pediatrician