Technical Tips: Performing EEGs and Polysomnograms on Children with Neurodevelopmental Disabilities

Abstract

Electroencephalograms (EEGs) and polysomnograms (PSGs) are critical and frequently ordered tests in the care of children with neurodevelopmental disabilities (NDD). Performing studies with this population can be very intimidating, given that the referral reasons and seizure types can be unique, and children with NDD may have any combination of behavioral or sensory challenges that can make it difficult to successfully complete a study. This article presents a variety of strategies that can be used to overcome these challenges through good preparation, patience, caregiver involvement, effective behavioral management techniques, and education about the medical aspects of EEG/PSG in NDD. This Technical Tips article features ideas and experiences from an EEG/PSG technologist, two board-certified child neurologists (one who is further certified in Clinical Neurophysiology, while the other is further certified in Sleep Medicine), and two behaviorally trained pediatric psychologists.

INTRODUCTION

Neurodevelopmental disabilities (NDD) include autism spectrum disorder, intellectual disability, cerebral palsy (CP), and attention-deficit/hyperactivity disorder (ADHD). Electroencephalograms (EEGs) and polysomnograms (PSGs) are critical and frequently ordered tests in the care of NDD because of a high incidence of epilepsy (Heller et al. 1996, Bowley and Kerr 2000), obstructive sleep apnea (Marcus et al. 1991, Kotagal et al. 1994), and sleep problems (Didden and Sigafoos 2001, Johnson and Malow 2008) in these populations. Successful completion of these studies is essential for obtaining critical information to manage these common co-morbidities of NDD.

If you do not have extensive experience working with children with NDD, you may be intimidated by the prospect of performing EEGs or PSGs in this population. There are a number of reasons for these concerns, as children with NDD may have any combination of sensory sensitivities, communication deficits, high levels of anxiety, and behavioral challenges that can make it difficult for studies to be completed successfully. Additionally, the referral reasons may be somewhat different from those in other populations, presenting unique challenges as you attempt to gain the most possible information from the study. You may also be less familiar with the waveforms being recorded, as they may not follow age-appropriate norms. Nevertheless, all of these challenges can be overcome with good preparation, patience, caregiver involvement, effective behavioral strategies, and education about the medical aspects of EEG/PSG in these disorders.

OVERVIEW OF NEURODEVELOPMENTAL DISABILITIES

There are many different types of NDD that you may encounter in the lab. Intellectual disability (previously called “mental retardation”) refers to a cognitive (thinking) disorder in which children develop more slowly than their peers and have significantly lower than average IQs. Diagnoses associated with intellectual disability include Down syndrome, Fragile X syndrome, Angelman syndrome, and Rett syndrome. A child with mild intellectual disability develops at 55 to 75% of the rate of peers, so a 6-year-old may understand and act like a 4-year-old. A child with moderate intellectual disability develops at a rate of around half that of his peers, so a 12-year-old may understand and act like a 6-year-old. A child with severe-to-profound intellectual disability typically has limited or no use of language. Remember that even if a patient’s “calendar age” is 10-years-old, a 10-year-old child with a cognitive age of 3 years cannot be expected to understand, focus, or behave any better than a typically developing 3-year-old.

Children with an autism spectrum disorder (e.g., autism, Asperger syndrome, and Pervasive Developmental Disorder, Not Otherwise Specified) will have challenges with social interaction and communication, are likely to be very routine-driven, and may have repetitive behaviors (e.g., hand flapping or other self-stimulatory behavior). Many children with autism also have intellectual disability, as well as hyperactivity and/or inattention, making it even more difficult for them to focus. Children with autism often have sensory sensitivities, in which they are excessively sensitive to touch, textures, and/or noises. They also may become distressed when their routine is broken – and an EEG or PSG is certainly out of anyone’s usual routine!

Cerebral palsy (CP) refers to motor impairments (“physical disabilities,” i.e., neurological difficulties with walking, arm usage, or other types of movements). Different types of CP may affect only one side, affect both legs (and, to a lesser extent, both arms), affect both arms and both legs, or cause excessive, involuntary movements. The term “CP” only refers to the child’s motor impairments, although intellectual disability, learning difficulties, and speech problems are often also present.

ADHD is a disorder that results in a combination of inattention (poor focus), hyperactivity (difficulty remaining still), and/or impulsivity (acting without thinking of the consequences). ADHD is quite common in children and can co-occur with the previously mentioned NDD.

GATHER USEFUL INFORMATION BEFORE THE FAMILY ARRIVES FOR THE SCHEDULED APPOINTMENT

It is always important to collect information about the child before the family arrives for their scheduled appointment, as this knowledge will guide you toward which strategies may be most effective with the patient. You will want to review the referral reasons to ensure that the study is scheduled appropriately to maximize the information that can be collected (e.g., if the goal of the study is to rule-out Landau-Kleffner syndrome, the EEG should be an overnight study). As you examine the medical records to understand the reason for the requested test, look for information such as the child’s medical diagnosis and current medications. Try your best to identify the child’s developmental level as documented by the child’s physicians, as this will be critical in understanding how to work with the child. Additionally, it is important to consider the child’s communication abilities and any documented behavioral concerns, as these things will significantly affect interactions with the child and family and will have a direct impact on the success of the EEG or PSG procedure. Since this information may not be readily accessible in the available records, it may be helpful to speak with the referring physician and the child’s primary care-giver before the family arrives for their appointment. Sample questions for your assessment can be found in Table 1.

Table 1.

Sample questions to consider during pre-appointment screenings.

Child Communication:	Child Personality:	Medical Information for EEG:	Medical Information for PSG:
Is the child verbal? If not, does he use a communication device? If so, will he be bringing his device to the lab? Does the child communicate via sign language? What is her comprehension level? Does the child prefer verbal explanations or instructions? If not, does he prefer visual prompting? Will I need to adapt my typical communication style for this child?	Is the child hyperactive? If so, what are calming activities for him? Does the child have sensory sensitivities? Is she sensitive to touch, and if so, on what parts of her body? Is she more comfortable with firmer or lighter touch? Is he sensitive to certain (i.e. grainy, sticky) textures? Is the child sensitive to certain sounds or sudden movements? How do the caregivers help the child cope with these sensory sensitivities at home? Is the child aggressive? Is it likely that he will try to hit or bite me? Does the child engage in self-injurious behaviors? Is she anxious in new surroundings or with medical procedures? What has been effective for minimizing anxiety during previous medical procedures or doctor visits? What things are comforting to this child? What are some of the child’s favorite movies, toys, books, etc.? Can these things be brought to the lab? What strategies have been successful or unsuccessful for the child during past procedures? Does the child nap? If so, when? Is it likely that he will be able to nap in the lab? Is it likely that the child will need additional preparation before the procedure?	What is the purpose of this study? Has the child had a previous EEG? What type of spells are under investigation? How frequent are the child’s spells? What are the triggers for the child’s spells? When are the spells most likely to occur? What is/are the medical diagnosis/diagnoses?	What is the purpose of this study? Has the child had a previous PSG? Is the main concern the child’s breathing? Or is it the child’s behavior during sleep? Is it likely that the child will need a full EEG? What is/are the medical diagnosis/diagnoses?

Communication

It is important to try to identify a child’s communication level prior to the appointment in order to maximize his or her comprehension, comfort level, and ability to tolerate the set-up process. It is key to assess a few important things about the child’s communication abilities and preferences. First, does the child communicate verbally (i.e., with spoken language)? Children who do not speak (either because of an intellectual disability or because they are physically unable to do so) may communicate with sign language or through an adaptive technology device, such as a voice output communication aid. Families should be encouraged to bring the device and interpret the sign language, if needed.

Second, what is the child’s comprehension ability? It is important to check with the families about this, as your instructions to the child should be at the level of their understanding (even if it is different from the level at which they speak themselves). It may be helpful to remember that a child with NDD might understand at a level that is below expectations for most children of the same age. For example, an 8-year-old with intellectual disability or autism may have language skills similar to that of a typical 3-year-old; in these cases, it is important to speak to the child as you would speak to a 3-year-old. Some children have an age-appropriate comprehension level, and should be spoken to at an age-appropriate level, even though they may speak like a much younger child. Some children who can understand verbal language may prefer instructions spoken to them, while others may prefer visual prompts (e.g., a picture of the electrode application).

Child personality

It is important to assess the child’s personality with questions such as: “How will the child respond when she comes into the lab? Is she anxious in new surroundings or with medical procedures? What has been effective for helping with anxiety during previous medical procedures or doctor visits?” Sometimes letting the child tour the lab before the day of the actual study can help in decreasing anxiety.

“Does the child have sensory sensitivities? Is she sensitive to touch, and if so, on what parts of her body? Is she more comfortable with firmer or lighter touch? Is the child sensitive to certain sounds or sudden movements? Or is he sensitive to certain (i.e., grainy, sticky) textures? How does the family help the child cope with these sensory sensitivities at home?” Answers to these questions can help the technologist know which PSG sensors, for example, should be applied last. The technologist may discuss with the lab physician whether photic stimulation is required in a child with visual sensitivities. Further, a technologist may use clinical judgment to determine how much skin abrasion will be tolerated before electrode placement.

“Is the child hyperactive? What are calming and comforting activities for the child? Is the child aggressive? Is it likely that he will try to swat at me? Does the child engage in self-injurious behaviors?” Some children do indeed have aggressive or self-injurious behaviors, and it is important to know this in advance to minimize risk to the technologist and maximize the chances of procedure success. It is important to keep in mind that aggressive behaviors are often intended as a form of communication or as the only way for the child to get what he or she wants, and the technologist must not interpret this as intentional hostility. Finally, the most important question is, “What strategies have been successful or unsuccessful for the child during past procedures?”

Gathering information for scheduling purposes can also be helpful for maximizing the success of the study. For daytime EEGs, naps can also be helpful, not only for increasing the diagnostic yield of the study, but also for helping the child tolerate the procedure. It may be helpful to ask, “Does the child nap? If so, when? Is it likely that the child will be able to nap in the lab?” For a child with difficult behavior, the technologist may need to schedule additional time for an EEG to be performed to allow for a prolonged set-up and sufficient recording time.

Medical information

Labs vary on the quantity and type of information they collect in the requisition process, but it may be helpful to obtain more information than usual when conducting an EEG on children with NDD. First, “What is the purpose of this study?” Many EEGs are performed to help differentiate epileptic seizures from nonepileptic spells. The diagnostic yield of the EEG increases greatly when a spell is captured during an EEG compared with an interictal recording in which the spell is not recorded. Because children with NDD may have spells many times per day (whereas most patients with diagnosed or presumed epilepsy may have spells only weekly or less often), there may be a better chance of recording a spell during a routine EEG in this patient population than in typically developing patients. Because of this, it is perhaps even more important to ask, “What is the frequency of spells? What are the triggers? When is a spell most likely to occur?” before recording an EEG on a child with NDD. If possible, schedule the study accordingly. It is important to ask the laboratory’s physician and/or referring physician, “Is it safe to try to provoke a spell/seizure?”, as precautions similar to those in an epilepsy monitoring unit (EMU) may be warranted. Additionally, children with NDD may have many types of spells, and it is important to understand from the referring clinician which types of spells are under investigation for your particular patient. Further, the referral for the current test may be to assess any changes from a previous EEG. In this case, it benefits you to review the tracing from the previous EEG(s) ahead of time to understand what you are likely to see during the recording.

Likewise, it is important to determine the referral reason for a PSG, understanding whether the study has been ordered to assess sleep-disordered breathing or sleep-related behaviors. Another potential indication for PSG in children with NDD is to determine whether nighttime spells represent parasomnias or seizures. Because the typical, limited EEG montage that is used in routine PSG is not adequate to localize epileptiform activity or even record it in all cases, it may be important to ensure that a more extensive EEG montage is used when the study is requested to address these questions. If the main concern is restlessness and nighttime arousals, documenting the circumstances for arousals during the night (whether spontaneous, noise-related, associated with wet diaper, etc.) becomes increasingly important. Also important for this type of referral is maintaining good leg lead recordings to document the presence or absence of periodic limb movements, a kind of rhythmic leg movement during sleep. The finding of frequent periodic limb movements can support (though not make) the diagnosis of Restless Legs Syndrome, a neurologic condition which can affect the ability to fall or stay asleep.

TECHNOLOGIST SKILLS

There are several useful approaches that you can take when working with children with NDD. Working with these children can be challenging under any circumstances, and it is critical to attempt to remain calm, patient, and determined in difficult situations. When performing these EEGs or PSGs, you should cultivate the mindset of enjoying challenges. Thorough preparation is critical. Before bringing the child into the laboratory, it is essential to have all equipment prepared and materials within easy reach. This will minimize the child’s opportunity to become restless while waiting for set-up. Additionally, you must be flexible, creative, and willing to quickly modify your typical routine when traditional methods of electrode and equipment application are not working. During the application process, the goal is to be efficient without seeming impatient. Finally, you must anticipate and prepare for things that may go awry during the procedure, such as child restlessness or undesired electrode removal. Although you will already be making modifications based on information gathered before the child’s arrival, it is always helpful to have a back-up plan.

BEHAVIORAL STRATEGIES TO USE WHILE THE CHILD IS IN THE LAB

Attempting a procedure and then stopping when the child becomes distressed or uncooperative can inadvertently reinforce (strengthen) these negative behaviors and make application more difficult in the future. Based on your pre-appointment assessment of the child, a variety of strategies can be used in the lab to increase confidence and caregiver trust in your ability to successfully accomplish studies on children with NDD. You should involve the caregiver, use developmentally-appropriate language, use the actual equipment to prepare the family for what is about to happen, apply the equipment strategically, and use distraction and other carefully selected behavior management strategies to maximize the chance of success.

Caregivers are an important part of the child’s EEG or PSG experience

Caregivers know their child better than anyone else, and it is critical to engage them and make them a key part of the team. Once a family is in the lab, ask the caregiver how their child will be most comfortable during equipment application (e.g., “Will your child be more comfortable sitting on on your lap, sitting in a chair, or sitting on the bed?”). Caregivers may be anxious about the EEG/PSG, either because they are scared that it will hurt their child or because they are concerned that the child will not tolerate the procedure well. Like most children, a child with NDD will pick up on a caregiver’s worries (or confidence) and respond accordingly, so it is critical to put the caregivers at ease quickly, even before the family enters the lab. If a caregiver is anxious, answer their questions and provide reassuring statements. If the caregiver is concerned about whether the child will be able to complete the procedure successfully, convey confidence to the caregiver that this procedure can be successfully completed (and has been completed in the past) with other children with similar disabilities. Additionally, demanding caregivers can be given a role in the setup for the procedure to positively channel their energy and concern. Solicit the caregiver’s help with blocking the child’s attempts at equipment removal, engaging the child in distraction, awarding stickers at appropriate times, and providing praise to the child for cooperation and tolerance of the equipment. If the caregiver seems detached or disengaged, find a role in the procedure to keep him or her involved, even if the role is a minor one. Placing a limit on parental electronic use during the set up process will also be important. For example, “I’m so glad you’re here! I could really use your help with distraction during the set up. I’ll also need your eyes and ears to watch for any changes in your child once we get all of the equipment on. Do you mind putting your phone away now?” Before proceeding, it can also be helpful to ask the care-giver if their child would benefit from additional preparation before the procedure.

Use the actual equipment to help prepare the child before beginning the application process

If the child or caregiver appears anxious, it can be beneficial to take the extra time to further prepare the child for equipment application. It is often helpful to show the child the electrodes, tape, and gauze before they are applied. Allow the child to put the facial scrub and electrode paste on her hand so she can feel the novel textures to alleviate anxiety before application. Additionally, you can let the child place an electrode on her caregiver’s hand as further assurance that the procedure is neither harmful nor frightening. Some children will be comforted by pictures of another child successfully completing the various steps of an EEG or PSG, providing further reassurance to the child that she too can be successful. Finally, it is important to answer any questions the child may have about the procedure, ranging from, “How long do I have to wear those wires?” to “Will that hospital bed go up and down while I’m sitting on it?” as this will further provide comfort and make the procedure more predictable. When explaining the amount of time required to complete the procedure, it can be best not to do so in terms of the number of minutes, but rather, to relate the time interval to an activity that is familiar to the child such as “about the time it takes to watch a Scooby Doo cartoon,” or “the time it takes to watch a Disney movie.”

If you do not have the time to provide this level of behavioral preparation and desensitization, the child’s physician can refer him to a pediatric psychologist or behavior therapist for this training prior to attempting the EEG or PSG (Slifer et al. 2008). Desensitization often involves scheduling outpatient practice sessions, ranging from one appointment to many appointments, depending on the child’s level of anxiety, hyperactivity, and sensory sensitivity. During these appointments, the child will have the opportunity to become familiar with and wear mock or actual equipment for short amounts of time. As the child becomes less distressed, the amount of time the child wears the equipment is increased until he is able to tolerate it for a length of time similar to that required for an EEG or PSG setup. Additional behavioral and coping strategies are also tried during these desensitization appointments to further maximize the child’s chance of success when he comes to see you for the actual procedure.

Apply the EEG or PSG equipment in a strategic order to maximize chances of success

Applying things in the same order presented during desensitization is helpful to children who have had this preparation, as this increases predictability and can be done along with pictures previously familiar to the child. Using a mirror can also be helpful, as this allows the child to see the equipment as it is applied. Additionally, sensors should be strategically applied to minimize the chance of removal. For an EEG, this may mean applying electrodes to the back and top of the head before applying electrodes to the face, and for a PSG, applying the nasal cannula before wrapping the head with gauze. Additional tape and gauze can be used to further secure equipment and prevent removal. For a child with sensory sensitivities, items should be applied to the most sensitive parts of their body last. Often in PSG, this means the nasal cannula is the final piece of equipment applied.

For a PSG, our experience is that it is best to apply equipment when the child is still awake, as this minimizes the chance that it will be removed if the child wakes (as he inevitably will) and is disoriented and distressed by the presence of unexpected equipment. As a last resort, PSG equipment can be applied after the child falls asleep, with the knowledge that the child may wake as the equipment is being applied or may remove the equipment upon waking. In general, it is better for the child’s ability to cooperate with the current and similar future procedures if he learns to tolerate the sensors while awake.

Communicate with the child and family at a respectful, yet developmentally-appropriate level regarding the procedure

As previously mentioned, it is important to remember that the child’s developmental level and chronological age may be different (e.g., a 12-year-old boy with a comprehension level similar to that of a 6-year-old), and your language must be adjusted accordingly. It is important to provide assurance to the child that neither the equipment application nor the procedure will hurt, and all of the equipment will be removed at the end of the procedure. Do not lie to the child about what will happen, or he will not trust you. Instead, be clear about anything he may be about to experience while phrasing it in friendly and non-threatening terms. For example, as you attach electrodes to the child’s head for an EEG, you might say “I’m using my special gel to stick this string on your head. Then I’m going to put a piece of tape on top of it.” As you wrap the child’s head with gauze, you may say, “I am giving you a funny-looking cloth hat.” For a PSG, you may talk about putting “stickers” on the child’s legs as you attach electrodes, or you may say “I’m putting on your tickly breathing tube” as you apply the nasal cannula. As you present each item, use child-friendly language to warn the child of the sensations they will experience (e.g., “This gel might feel a little cold and gooey to you,” or, “This tape may pull your skin a little as I take it off.”) For children who are rule-bound, additional prompts, such as “Only grown-ups get to take these things off, so let me know if something bothers you or feels funny,” can encourage tolerance. If the child’s verbal comprehension is poor, it may be useful to provide him with nonverbal visual cues (i.e., pointing or gesturing while holding the equipment) or pictures as you explain the procedure. Either photographs of a child having equipment applied or clip art graphics depicting approximations of application steps can be used for these visual explanations.

Give choices whenever possible—they let the child feel less anxious and more in control

If appropriate, it can be effective to allow the child to make choices regarding equipment application. Children may feel more comfortable (and therefore less nervous) even when given choices that have no practical consequence at all (e.g., “What color of wire should we use first: black or red?”). However, when allowing children to make choices, it is important to provide guidance by offering two choices for the child to select from (e.g., “Shall we put the first wire on the side or on the back of your head?”) so the application process can continue. Be cautious when phrasing these questions: if questions are phrased in a “yes/no” format (e.g., “May I put this electrode on your head?”), the child will potentially (and very likely) answer “No!” Finally, if he is able, let the child help with electrode application by holding the gauze or roll of tape as you apply his electrodes. This involvement serves a two-fold benefit of engaging the child in the procedure and keeping his hands occupied, making him less likely to remove the items as they are applied.

Utilize appropriate distraction during equipment application

Children of all developmental levels often respond well to distraction with either favorite items (e.g., their blanket) or novel items (e.g., a new toy). During pre-appointment screenings, families should be encouraged to bring preferred toys, books, or favorite DVDs (and if one is not available in the lab, a portable DVD player) to their appointment. Additionally, it is recommended that a range of books, toys, or movies that span many developmental levels be kept in the lab. Handheld items (e.g., small video games, books, pop-up toys, rattles) serve the added benefit of keeping a child’s hands engaged as you apply the equipment. Distracting items should be introduced to the child prior to equipment application to maximize engagement in the activity.

Cooperation can be further enhanced by setting clear expectations and providing consistent feedback

Instructions should be delivered at the child’s developmental level to maximize the chance of compliance. Even non-verbal children can understand and will respond to tone of voice: a negative tone of voice can produce negative behaviors so instructions should be delivered in a neutral, non-confrontational manner. If a child begins to reach for an electrode, attempt to gently block/redirect his hand before he is successful, provide a neutral reminder (e.g., “Hands down.”), and attempt to engage him in another activity. Whenever possible, ignore and do not verbally respond to mildly inappropriate behaviors (e.g., whining, fussing, pouting, irritability). In order to get the best out of the child, it is very important to provide praise (e.g., “Good job keeping your hands down,” or “I like how you’re playing with that toy right now”) and positive attention (e.g., smiling, clapping, whatever response is enjoyable for the child) much more often than negative feedback. Remember that some forms of praise may be uncomfortable for some children with NDD (e.g., those with sensory sensitivities may be bothered by clapping or cheering), so ask the child’s caregiver to show you how they typically praise their child at home.

For children who need immediate feedback, it can be useful to provide a sticker following the application of each piece of equipment. For an anxious child, it can be helpful to allow the child to “count down” as electrodes are applied to each section of their head (e.g., “Now we’re all done with the back of your head. Great job! You can put a sticker on the paper. Next is the side of your head.”) For short studies, anxious children may also respond well to visual timers depicting the remaining amount of time they need to wear the equipment.

A small percentage of children with NDD are aggressive; a few techniques can minimize chances of harm

Aggression in a low-functioning child may be his only form of communication and often does not represent a desire to hurt someone. Before starting, discuss with the caregivers any history of aggressive behaviors and what can be done to avoid them. Enlist their help with the set-up. Beyond that, if you are working with an aggressive child, it is important to be aware of your positioning to ensure your safety. Remain out of the child’s reach (both arms and legs) as much as possible, and if you have long hair, keep it pulled back out of the child’s reach. You can also attempt to apply as many electrodes as possible while standing behind the child. To further ensure your safety, it may be helpful to refer to your lab’s policy on addressing aggressive behavior from patients.

You may encounter families who specifically request that their child be papoosed or swaddled for their EEG or PSG

In general, we do not recommend the use of papoosing to increase child compliance, because using the aforementioned behavioral strategies often allow children with NDD to successfully complete their EEG or PSG procedure without being restrained. Providing children with the opportunity to learn how to complete a procedure unrestrained will often improve tolerance for the current and future procedures. For example, a child papoosed during PSG set up will likely attempt to remove all applied equipment once the papoose is removed. Families may also indicate that their child feels comforted by being securely wrapped. In this instance, you could encourage a caregiver to engage their child with a previously identified calming activity or to provide a hug (or other close contact) to their child. Additionally, many labs have policies that prevent the use of restraint. In our lab, papoosing and swaddling are viewed as types of restraint and are typically avoided in an effort to minimize the potential for controversy and to provide medical services in the least restrictive environment possible. One instance in which papoosing is used in our lab is when restraint is professionally prescribed as part of the child’s home care routine. In these specific instances, parents are required to do the papossing/swaddling in the lab (as opposed to having you do it). Finally, sedation/anesthesia is not recommended as a child behavior- or anxiety-management strategy for EEGs or PSGs. Limited lab resources for medical monitoring make these medication interventions difficult, and the medication may adversely affect the child (paradoxical response, respiratory depression, nausea and vomiting) and the study outcome (leading to a repeat study being ordered).

Experienced technologists often must make clinical judgments about how to perform the study

You should always strive to record studies that conform to or exceed American Clinical Neurophysiology Society (ACNS) and International Federation of Clinical Neurophysiology (IFCN) standards, just as you would for any patient. However, there are situations in which modifications may need to be made because collecting some information may be better than collecting no information at all. For example, it is important to strive for impedances within the appropriate range. In children who have significant scalp sensitivities, it may be the “lesser of two evils” to forego intensive scalp preparation so that the child will allow you to apply any electrodes at all. Similarly, if an electrode falls off of a patient who has settled down after having difficult behavior during a prolonged set-up, you should take into account the goal of the study (e.g., what information is needed to answer the clinical question that is being asked), the interpreting physician’s experience and preferences, and the behavioral “cost” of making additional interventions. It is generally worthwhile to work towards obtaining the best possible signals by the end of set-up at the start of the study, rather than taking shortcuts for a challenging patient with the hope of doing significant troubleshooting later in the study.

Regarding PSG, mouth breathing is commonly observed in children with NDD. This can make obtaining optimal airflow signals challenging. In addition, the nasal cannula can be hard for children with (or without) NDD to tolerate. While gentle replacement throughout the night must be attempted, you should think about which other signals can compensate for the absence of a good nasal pressure signal or thermistor, including the combination of thoracic and abdominal effort signals. Excellent pulse oximetry throughout the night is mandatory. Some children are distracted by the red light on the pulse oximeter, so placing it on a toe underneath a sock can decrease the distraction factor and make it less accessible for removal. Video monitoring and recording can be aided by thoughtfully refocusing the camera. For example, if rapid eye movement (REM) sleep is in question, capturing a closeup of the face for eye movements can be helpful; if limb movements are recorded, the broader picture of the patient’s body, including legs, is helpful.

EEG FINDINGS DURING THE RECORDING

Children with NDD have a wide variety of seizure types

You should become familiar with the seizure types that are common in children with NDD. These include not only seizure types seen in individuals without NDD, such as complex partial seizures (from any lobes), primary and secondarily generalized tonic-clonic seizures, absence seizures, and myoclonic seizures, but also seizure types more unique to individuals with NDD, such as tonic seizures, atonic/astatic seizures, and atypical absence seizures. You should review the requisition as well as other medical records when possible, but reviewing the seizure/spell history with the caregiver is critical. During the recording, you should be aware of the type of spell that the referring clinician wants to record; you should also be aware of any types of spells that the patient has—it is important to keep a sharp eye out. Caregivers should be given an event button (or other way of indicating that a spell has occurred) and should be responsible for watching the patient closely and reporting immediately whenever a spell occurs. You should ask the caregiver to explain whether the spell that just occurred was a typical spell or a new type of spell; this information should be included as an annotation on the record. Even though video is helpful in many recordings, you should also make careful observations and annotations of the patient’s behavior that may indicate a seizure. It is possible that you may recognize subtle seizures that have not previously been recognized by the caregivers. If no spell occurs during a recording, you should annotate this fact in the file just before the EEG is complete so that it is clear to the interpreting physician.

EEG patterns may be abnormal in children with NDD

Children with NDD may demonstrate the full range of abnormalities in their EEGs, including focal and diffuse slowing as well as focal and generalized epileptiform patterns. Since children with NDD often have multiple EEGs over their lifetimes because of their complex and evolving medical situations, there may be previous EEGs for you to review prior to the current study. This step will allow you to know what to expect and what findings constitute a change from previously recorded EEG patterns. In general when dealing with patients with NDD, you should be acquainted with the full range of ictal patterns, including partial seizures, electrodecremental patterns, and generalized ictal patterns. Because individuals with NDD sometimes have multiple seizures per day, it is more likely that you will capture an actual seizure during a routine recording (and not just during an EMU admission). Electrographic ictal patterns may occur without recognized clinical signs, and it is important that you be a careful observer and try to interact with the patient during any possible electrographic seizures to see if there is a change in level of alertness or cognition. You should also be aware of patterns that are consistent with nonconvulsive status epilepticus and electrical status epilepticus in sleep (ESES). Annotations regarding behavioral state are also critical in helping the interpreting physician understand whether anticipated EEG state changes are seen and whether changes in the EEG correspond to behavioral state changes.

If you are performing baseline PSGs with a limited EEG montage on patients with NDD (who are not referred for concerns of seizure), you should be aware that these children may show incidental epileptiform activity or even seizures during their studies. These abnormalities may or may not have come to clinical attention previously, but should be noted so that they are brought to the attention of the interpreting clinician. Thus even for PSG, seizure history in children with NDD is important.

Medical care

Neurophysiology laboratories should have policies regarding seizure and non-seizure emergencies. As for any patients, technologists caring for children with NDD should be aware of seizure first aid and should also know the protocol to follow if either the pre-study history or the EEG uncovers seizures that were not previously recognized. You should be aware of resources in your clinic or hospital for summoning emergency medical care. Children with NDD may have severe breathing problems resulting in oxygen desaturations.

While running PSGs, you will want to be familiar with your laboratory’s policies about when to continue baseline studies and when to initiate interventions. Split night studies, in which a baseline PSG is converted to a titration of continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP) or supplemental oxygen, may be relatively contraindicated in children with NDD. For many children, surgery such as adenotonsillectomy is considered first-line treatment for disorders such as obstructive sleep apnea. In the short term, although children’s respiratory status may benefit from positive airway pressure, the sudden introduction of an unfamiliar and potentially uncomfortable treatment during the night can have long-reaching effects on future compliance. Supplemental oxygen may be helpful for some conditions, but ineffective in others, such as obstruction, as the flow of oxygen likely will not overcome airway blockage. You should familiarize yourself with your laboratory’s policies about initiation of treatment, and seek consultation with supervisors when necessary. Additionally, children with NDD may have a number of medical issues which are unrelated to the reason for the study; the inpatient medical team (for inpatients) and the caregiver (for outpatients) would typically be responsible for the care of the child’s medical issues.

DISCUSSION/CONCLUDING REMARKS

There are a number of considerations specifically related to the successful performance of EEGs and PSGs in individuals with NDD. The suggestions presented here are the result of the experience of a team that specializes in working with pediatric patients with NDD. We have the luxury of partnering with colleagues with a wide range of training and experience in different facets of care of children with NDD, and we are located at an academic institution that specializes in the care of children with NDD. Our team consists of EEG/PSG technologists who perform hundreds of EEGs and PSGs in children with NDD every year. The team also includes two board-certified child neurologists who are additionally certified in the fields of Neurodevelopmental Disabilities and Pediatrics; one is further certified in Clinical Neurophysiology (and has a clinic for children with NDD and epilepsy), while the other is further certified in Sleep Medicine (and runs our sleep center). Our team also includes two behaviorally trained pediatric psychologists.

Each child is different, and we find ourselves thoughtfully improvising on a regular basis to get the best results. While we cannot guarantee that these procedures will be effective in every case, we do know from our own practices that with appropriate preparation and desensitization the vast majority of children, including those with mild to severe NDD, can learn to successfully tolerate EEG and PSG studies. We believe this level of success requires specialized training and experience working with youth with NDD. The best way to get this type of training is to work in cooperation with an experienced and successful technologist at a practice that regularly works with children with NDD. Such individuals or teams can be found at children’s hospitals or the department of psychiatry and/or pediatrics at many university affiliated medical schools. Training can be obtained by working as an intern or apprentice at the type of practice mentioned above, or by obtaining consultative services from an experienced facility or practice. Behaviorally trained pediatric psychologists can provide desensitization protocols in their own setting and work with the family and medical caregivers to transfer the benefits of behavioral interventions to the laboratory where a child’s EEG or PSG is ultimately conducted. When such training is not possible, many technologists will find that over time, practice with pediatric patients with NDD will result in greater comfort with these patients and better study outcomes. Additionally, you may find that previous skills acquired while performing EEGs or PSGs with the elderly (particularly those with neurological disorders, such as dementia) can be transferred, with some modification, to caring for children with NDD.

With proper education, practical training, and consultation, the procedures discussed in this article can become “second nature” to you. Once integrated into your practice, many children with behavioral, anxiety, and/or neurodevelopmental difficulties can receive the benefits of state-of-the-art electrophysiological assessment technologies and the high quality medical care that follows such expert assessments.