Is there a link between those suffering from Epilepsy and untreated Sleep Apnea? I just read about an amazing 10-year case study from the Cleveland Clinic in which a patient who had been diagnosed with epilepsy at an early age was “experiencing epileptic seizures as frequently as once a day and convulsions occurring about once a week. Even though this patient was not overweight, had only mild snoring, and showed no regularity of cessation of breathing during the night, the site decided to conduct a sleep study because sleep apnea has been associated with worsening epileptic seizures. This patient was put on continuous positive airway pressure (CPAP) therapy and within 2 months his seizures stopped altogether.” During a 10-year follow-up period, the patient still remained seizure free.
This begs the question. If there is an already well-recognized association between obstructive sleep apnea and epilepsy from existing data, why aren’t more Epilepsy and Neurology Programs screening and referring their patients to sleep studies?
You may be asking yourself how someone who started an online sleep store could know anything about Epilepsy and Sleep Apnea. Well, for 5 years I worked for one of the world’s largest manufacturers of Neuro and Sleep diagnostic equipment.
My installations included some of the top Epilepsy and Sleep programs in the country, as well as your local 300-bed Hospitals. I’ve had first-hand experience in seeing how Epilepsy/Neurology and Sleep programs at varying hospitals work together or the complete lack thereof in most cases. I will do my best to explain how these departments work together currently, where there is drastic need of improvement, and why in most cases it is non-existent.
EEG vs. Sleep Testing
Would you be surprised to learn that the equipment used to record your brain activity in an Epilepsy Monitoring Unit (EMU) or EEG Laboratory can be the exact same as the equipment used for a Sleep Test? Literally…..the exact same. The only difference is the channels recorded during the study, and how they display in the software program that digitizes the signals into readable waveforms.
An amplifier is the piece of equipment that is used to record your brain, muscle, pulse, and respiratory activity. It does this by utilizing different channels with sensors plugged into them. These sensors attached to your body to record the data.
- Referential Channels: These channels are used specifically for EEG recordings. An amplifier can have anywhere from 32 to 512 referential channels with sampling frequencies ranging from 200Hz to 14,000Hz. Electrodes are plugged into these channels and then placed on the scalp to record your brain activity.
- Differential Channels: These channels are needed to record signals like respiratory activity, EKG, and EMG. Respiratory belts that attach to the chest and abdomen, Thermistors, and other sensors all use these channels that are needed for a sleep study. Specific amplifiers offer both Referential and Differential channels so that they can be used for both EEG and Sleep.
- DC (Analog Channels): These channels capture an analog signal from an external device like a CPAP or End Title CO2 system. These are more frequently used for sleep.
- Pulse Oximetry: A pulse oximeter is available on almost any amplifier and is used mainly for a sleep study. However, more and more EEG studies are starting to record this channel
So, if an EEG study is recorded how can a Sleep Specialist look at that study to determine if Sleep Apnea may be present? Well, the software used to display and analyze the recorded data can be a “Dual” EEG/Sleep software. So you could take that completed EEG recording, run automated sleep analyzers on it, and get new information that may show Sleep Apnea events.
This is why it is in the best interest of the Neurology Department to record additional channels such as pulse oximetry, EMG for arms or legs, and a respiratory channel. The more information that can be pulled from that EEG study into the sleep software, the better chance a Sleep Doctor can determine if the patient is showing signs of sleep apnea and in need of a full sleep study.
What Type of EEG Studies Are Ideal For Sleep?
The Neurodiagnostics market is expected to grow about 9% over the next 4 years. This is fantastic news as these types of Diagnostic studies are underutilized in many areas. If a Neurology and Sleep Department are truly going to work together to identify and treat sleep apnea for epilepsy patients, one key factor needs to be present. The patient getting an EEG test needs to actually sleep!
The most common EEG test is a simple outpatient study that lasts anywhere from 30 minutes to 3 hours. These tests are not long enough for the patient to sleep, so it pretty much limits any opportunity for Sleep and Neurology to work together outside of a direct referral to the sleep lab.
Long Term Monitoring (LTM) is where the true potential lies. Long-Term Monitoring in EEG can be anywhere from 24 hours to 60 hours long. This means that the patient will continue their recording throughout the day and night while they are asleep. The patient is monitored by an EEG technician at all times, and this technician can be taught to recognize certain signs of sleep apnea. Furthermore, the technology allows for the Physicians to view the study in real time anywhere outside of the hospital (at home, while on vacation, wherever). A Neurologist or Sleep Doctor can quickly log-in to the live study at 3 am while you are sleeping, open it up with full video and audio, listen to your breathing or snoring, watch the movements of your arms and legs, and make notes.
If throughout the night the Technician or Neurologist see signs of sleep apnea, they can contact the Sleep Physician to take a look. The Sleep Physician can run sleep analyzers and determine if a full sleep study is needed for the patient. It becomes even easier for cross compatibility when the sleep department is using the same equipment and software as the Neurology Department. Study files can be shared, access for all Physician groups can be easier, and the system is working in the most HIPAA compliant format.
When is Long Term EEG Monitoring Used?
- Epilepsy Monitoring Units (EMU): If you walked into a sleep laboratory and then an EMU, you may have to do a double take to be sure you’re in different places. The set up for both is pretty much the same. You will be spending your time in what looks like a hotel room for one. There will be a camera in the ceiling or on the wall that can record video and audio, an amplifier next to a bed to record your brain activity, and possibly a PC running the EEG software somewhere in the room. The length of your study can vary from one day to a few, but the important thing is that every night you are tested it allows for your sleep to potentially be monitored. A perfect set up when considering possible links between sleep apnea and epileptic events in that patient.
- Intensive Care Units (ICU): Long-term EEG monitoring in the ICU is vastly under-used. In a 2010 study, one-quarter of Neuro-ICU patients with cerebral hemorrhages were found to be having sub-clinical seizures when given a continuous EEG study. This means they were having seizures even though they were showing no physical signs of it. It’s also been shown that up to 8% of all ICU patients suffer from obstructive sleep apnea. While the ICU makes it difficult to obtain adequate data for a sleep study due to environmental factors, constant wakes, and few changes in body position, it is the perfect opportunity for a Long Term EEG study for a patient base that needs it.
- Ambulatory EEG: An ambulatory EEG system is one that is sent home with the patient for a continuous study in the comfort of their own home. It records in the exact same fashion as any other amplifier, it just does not allow for real-time monitoring by an EEG tech or Neurologist. The data and video record to local storage devices. Many of these also have the necessary channels for a sleep study, so it’s very easy to pull sleep parameters from the EEG study if desired.
The use of Long Term EEG Monitoring is growing, but it is still in no way utilized to its full capacity. Much of that has to do with resources. There is a shortage of certified EEG and Sleep Technicians for starters. If you are interested in a new career path, these are well-paying specialties that are in large demand. Likewise, you need a Neurologist who is willing to take responsibility for a monitored patient who can have a seizure at any time of the day. When they leave the hospital they have to be willing to take those 3:00 am calls from an ICU nurse regarding a patient, get out of bed, log into the remote software, and look at the study. Even if you have both of these, you still need the Hospital to invest in the equipment and IT infrastructure to truly have the full capabilities.
With all of that said, there is still an enormous group of patients that are receiving Long Term EEG’s, and more hospitals are adopting the technology to do so. Most of these patients should be looked at for signs of sleep apnea.
Neurology & Sleep Cooperation Today
In the case study referenced at the beginning of this article, you saw how a Neurology and Sleep Department within a hospital system worked together perfectly for the benefit of the patient. Sadly, this is not as common as it should be. For the most part, sleep and neurology departments do not work together. They are two completely separate entities in the hospital with different managers and directors. Their first concern is treating their patients and providing positive outcomes. After that, it’s making sure everything is running like a well-oiled machine. They have turnover, expenses, budgeting, fires to put out, and profitability goals. Taking on more responsibility in an already chaotic environment usually doesn’t get a lot of backing.
Infrastructure is also an issue. Large institutions who do work together across departments have invested large sums of money into the same equipment, software, IT infrastructure, and training necessary for a successful Sleep/Neuro collaboration. Any site can do this, but they’ll run into some hurdles:
- Sleep/EEG Platform of Choice: Physicians are creatures of habit, and breaking that habit can be near impossible. If a Sleep MD or Neurologist have only ever used one software program to record and review their studies, getting them to change is going to be a battle. This change is ultimately going to fall on the Sleep Department’s lap. There are only a few companies that have the technology in place for true Long-Term EEG Monitoring with a Sleep Component built in. Conversely, there are numerous Sleep Diagnostic systems on the market, but many of them can’t do EEG. So in all likelihood, the Sleep Lab is going to have to replace a system that they’ve been using for many years. This is why they need to be involved in the decision-making process for the equipment and software Neurology chooses.
- Hospital Funding: Hospitals are not dripping cash right now, and buying decisions are being directly affected. If both Sleep and Neurology have existing diagnostic platforms in place, and the cost of simply upgrading those is $200,000 less that a complete overhaul, you’re likely going to get turned down for the larger purchase. There have been numerous instances where the buy-in for creating a program like this has been accepted by the Physicians, Managers, and Directors but ultimately shot down in Financing and Purchasing once the price tags were seen. Hospitals are not great at looking at the long-term when staring at a big price tag.
Not all hope is lost, though. Hospitals are starting to combine departments where Managers and Directors are responsible for multiple programs. Not surprisingly, we’re seeing more and more Sleep and EEG programs getting put under the same department. This allows for 1 Manager to work with both physician groups on future endeavors. Hospitals are also learning to do these projects in phases. Instead of a lump sum cost, they can spread the project out over 3 years and budget accordingly. This just takes some hand holding and making sure everyone is on the same page.
If you are a patient who has been diagnosed with epilepsy, or are experiencing seizures, know that untreated sleep apnea has shown to increase epileptic events. As you go through your diagnostic and treatment protocol, it is important to discuss this with your medical team. Ask the right questions.
- How much collaboration exists between your facility’s Neurology and Sleep Departments?
- Is the Neurology team trained to identify possible signs of Sleep Apnea?
- Should I have additional channels like Pulse Oximetry, EMG, or Respiratory recorded during my EEG study?
- If I have never been tested for sleep apnea, should I?