Strategies proposed for treating fear episodes in juvenile Batten disease
Efforts include minimizing provoking situations, increasing pain threshold
Managing fear episodes in people with juvenile Batten disease requires minimizing situations that provoke patients, and increasing their threshold of pain and discomfort, a study reports.
Sedative medications and therapies that activate specific areas of the nervous system may also help manage such responses, but solid evidence for them is lacking, meaning more research is needed, said the author of “Treatment of non-epileptic episodes of anxious, fearful behavior in adolescent juvenile neuronal ceroid lipofuscinosis (CLN3 disease),” which was published in Frontiers in Neurology.
Juvenile Batten disease, also called CLN3 disease because it’s caused by mutations in the CLN3 gene, is marked by symptoms such as vision and cognitive problems, and seizures that appear during childhood.
In their late teens, most juvenile Batten patients will begin having intense fear responses, such as a fearful expression, hiding or clinging to furniture, and an elevated heart rate and sweating.
These episodes can sometimes happen without a clear trigger, but are most often associated with uncomfortable or experiences — being unexpectedly left alone, exposed to loud sounds, or being in pain.
Fear episodes, which at later disease stages may last up to an hour or for days, can distress patients and caregivers, and have been linked with a poor prognosis.
What triggers fear response?
A researcher in Denmark reviewed the available scientific literature about why people with juvenile Batten experience fear episodes to explore how they could be treated.
A major cause of fear responses in juvenile Batten disease is a reduced pain threshold. Touching a patient in a way that might not affect a typically developing person may cause them discomfort.
Because pain can trigger fear in anyone, preventing or minimizing juvenile Batten patients’ discomfort or pain “should have the greatest priority,” the researcher wrote.
Strategies for doing this include having a fixed daily routine so patients aren’t surprised by unexpected stimuli and taking steps to address physical issues that can cause discomfort, such as constipation or dehydration.
The researcher noted emotions are “contagious,” especially for Batten patients who have limited ability to regulate their own. For this reason, caregivers should stay outwardly calm and be gentle to help stave off their discomfort.
Also, a long-term plan that’s started early on to handle situations that could trigger fear responses “will, through habituation and conditioning … probably reduce the fear induced by these situations,” the author wrote.
Medicines to treat fear response in juvenile Batten
It’s believed that the reduced activity of the brain signaling molecule GABA plays a major role in driving fear among juvenile Batten patients. While there’s no solid data to support any treatment for fear episodes, data from people in whom a brain injury resulted in fear responses similar to those in juvenile Batten suggest GABA signaling-increasing therapies may help.
The anti-seizure medication gabapentin and the analgesic fentanyl may increase the pain and discomfort thresholds of people with juvenile Batten. Sedatives like midazolam or clonazepam have also shown promise for preventing and treating fear episodes.
Another neurological driver of fear in juvenile Batten is an imbalance between the sympathetic and parasympathetic nervous systems. The sympathetic nervous system activates the body’s “fight or flight” response, triggering a faster heart rate and rapid breathing. The parasympathetic nervous system turns off these changes once a threat has passed.
In people with juvenile Batten, the parasympathetic nervous system becomes increasingly dysfunctional as the disease progresses, resulting in patients having sympathetic system overactivity, which drives the physical sensations of a fear response.
In theory, treatments to activate the parasympathetic nervous system may help reduce patients’ fear. One way to do this could be with vagus nerve stimulation, where an electrical current stimulates a large parasympathetic nerve.
Vagus nerve stimulation to treat fear in juvenile Batten disease hasn’t been explored in published studies, but should be a priority, the researcher wrote.