Prognosis, or the forecast of the likely course of a disease, is often dependent on phenotype and timely intervention. Below, you can find more information about predicted prognosis for epilepsy, development and seizure freedom, the impact of variants and SUDEP risk.
Understanding the Possibilities with SCN8A
Dr. Christelle Achkar from Boston Children’s Hospital gives a short overview of the future outlook for those diagnosed with SCN8A, discussing the variability in prognosis depending on the specific phenotype. Explore further details below to access comprehensive resources and support tailored to SCN8A families and clinicians.
Prognosis for Epilepsy & Development
The table below outlines the likely change over time, for both seizures and development, over time for each phenotype.
There was no consensus about the expectations for seizures in Severe DEE over time. There was a mix of expectations ranging from some respondents expecting that seizures would improve over time while others thought they were likely to worsen. In contrast, there was consensus that seizures would either have modest or significant improvement over time in Mild/Moderate DEE, SeL(F)IE and NDD with Generalized Epilepsy.
There was consensus that development in Severe DEE was not likely to improve. In contrast, there was consensus that development would have limited change or modest improvement over time in Mild/Moderate DEE, SeL(F)IE, NDD with or without epilepsy.
Likelihood of seizure freedom by phenotype
There was moderate consensus that Severe DEE was rarely likely to achieve seizure freedom, Mild/Moderate might achieve seizure freedom some of the time and NDD with Generalized Epilepsy is likely to achieve seizure freedom some or most of the time. The SE(L)Fie phenotype, while not listed in the table, almost always achieve seizure freedom.
* For the purposes of this consensus, we define seizure freedom as going 6 months or longer without having a seizure.
Supplemental Information on impact of individual variants on outcomes
A recent paper by Dr. Kyung Mi Chung in Dr. Hammer’s lab identified statistically significant correlations between genotypes and phenotypes for individual SCN8A variants with GOF properties. The results suggest that individual GOF variants
(1) are predictive of clinical severity for individuals carrying those variants and
(2) may underlie distinct clinical phenotypes of SCN8A disease, thus helping to explain the wide SCN8A-related epilepsy disease spectrum.
These results also suggest that clinical features present at initial diagnosis are predictive of clinical severity outcomes. This work suggests that more informed and tailored treatment plans may serve to improve prognosis for patients with SCN8A GOF variants.
SUDEP Risk
Risk factors for SUDEP are recognized as uncontrolled or frequent seizures, frequent generalized convulsive seizures, early age of seizure onset, many years of living with epilepsy, lack of treatment for seizures, reliance of three or more ASMs, and multiple ASM changes in the last year.
Both clinicians and caregivers agreed that severe risk for SUDEP is present in Severe DEE, as defined by the estimated presence of multiple risk factors including uncontrolled/frequent seizures and frequent generalized convulsive seizures. Clinicians and caregivers felt that SUDEP risks were unlikely to improve or resolve, highlighting the need for better understanding of SUDEP across all phenotypes and strategies to reduce the risk. For more information and additional resources on SUDEP, please visit Partners Against Mortality in Epilepsy.
The authors concluded there is a need for investigation into the risk and causes of SUDEP as well as potential strategies to reduce the high rate of premature deaths in the SCN8A population.
Learn More
– Keep Exploring –
IMPORTANT: While this consensus data provides new and valuable insights about best practices in the diagnosis and treatment of SCN8A, this is not medical advice. It can inform clinicians and caregivers alike in developing optimal treatment plans for each individual.
Disclaimer for Consensus and Individual Variation
This consensus process was carried out by a panel of expert clinicians who actively treat patients with SCN8A-related disorders. Guidelines determined from a consensus differ from those determined from a population-based study*. The extent of consensus reached is restricted by the number of patients seen by each clinician and the portion of the disease spectrum these patients represent.
Consensus guidelines serve as a recommended starting point for clinicians to treat patients based on the best evidence available. If an affected individual does not fit the expected profile, it is important to reassess your treatment plan and revise accordingly. Reassessment of the consensus guidelines will occur as new data become available and the number of patients seen by clinicians increases.
Guidelines based on future consensus processes will therefore reflect advancements in clinical care.
*Population-based studies reveal general trends for large subsets of the population. It is important to remember that each individual is unique and may not necessarily follow these trends regarding developmental progression, seizure remission, or effective treatment.