Clinical diagnostic pathway for CHD2
Pathway for children and infants
The following is the most likely route you will take in order to get a clinical diagnosis in England. Medical professionals may skip several of these stages if they feel confident that specialists at a regional hospital (Tertiary Centre) need to be consulted.
This process will differ to a certain extent in Scotland, Ireland and Wales and we will endeavour to add those pathways in the near future.
Generally speaking, CHD2-related neurodevelopmental disorders are characterised by early seizure onset which usually occurs within the first five years of life. You might also have been aware prior to seizure onset that your child wasn’t reaching their developmental milestones. They may have been slow to walk, have delayed speech, language and communication difficulties and autistic behaviours. For a very small number of individuals it has been reported that development may have progressed normally before seizure onset.
Developmental Delay
If it is suspected that your child is slow to hit their developmental milestones and is not progressing in a neurotypical manner then your health visitor, GP/doctor or community nurse in primary care may refer your child to be assessed by the Child Development Centre at your local Hospital. Medical assessments, carried out by audiology and/or optometry etc. may also take place in an attempt to rule out a physical rather than a neurological cause and your child will be closely monitored. An early years assessment or similar might be carried out by your local Child Development Centre and this might involve a joint assessment by the Consultant Paediatrician, Speech and Language Therapist and Early Years Specialist.
Seizure onset
In many cases the onset of seizures occurs as a consequence of an illness usually with a high temperature which causes a child’s seizure threshold to be lowered. A single seizure episode usually gives no concern to a GP, but after further ones, and when considered alongside the other elements of developmental delay, then the paediatric consultant at your local hospital is likely to get involved.
Paediatric Consultant
The Consultant Paediatrician and in some cases the Consultant Neurologist at your local hospital (Secondary Care) will take a detailed medical history and may also make a physical examination. They may refer onto other medical professionals for routine medical checks if this hasn’t already taken place.
An EEG (electroencephalogram) may be requested in order to help identify the type of epilepsy and what area of the brain might be triggering the seizures as this will determine the best treatment to take. If unusual seizure activity is identified then anti epilepsy drugs will be prescribed. Regular appointments will then be made with the Consultant Paediatrician to monitor progress.
Health Professionals
Numerous health professionals are likely to get involved depending on the child’s needs and may include the Speech and Language Therapist (SALT), Occupational Therapist (OT), and Physiotherapist etc. If your child is exhibiting psychological difficulties, then a referral to the Child and Adolescent Mental Health Service (CAMHS) might be made to be assessed by a Clinical Psychologist or Clinical Psychiatrist. This is usually where an autism assessment (ADOS) will take place or a test for ADHD or similar. If necessary, there may be a referral onto a Neuropsychologist or Neuropsychiatrist.
Regional Neurology Centre
If seizures remain uncontrolled by anti-seizure medication there will be a referral onto a Regional Neurology Centre (Tertiary Care) for further investigations. Here they will take a clinical history and review the medical history yet again. They will conduct further detailed tests, such as a 24 hour EEG, MRI or CT scan and based on their findings will try and treat the condition primarily using several anti-epilepsy drugs. If numerous anti-epilepsy drugs have been unsuccessful you might be offered the opportunity to try a Ketogenic diet or the possibility of Vagus Nerve Stimulation (VNS).
If detailed specialist diagnositic tests are inconclusive or, in order to confirm a suspected diagnosis, they may also undertake genetic testing.
Genetics centre
Genetic testing usually involves donation of a blood sample or saliva, not just from the child but also the biological parents. If the genetic test is positive (pathogenic) or if it is a variant of uncertain significance (VUS) there will be a referral to a genetic counsellor. These counsellors will help families understand the implications of their test results and address parental concerns. The genetics centre will then signpost you to relevant information and support groups.
In some cases you might be referred onto a highly specialised paediatric neurology centre, such as Great Ormond Street Hospital or similar, particularly if several genetic mutations are identified.
Pathway for adults
CHD2 related disorders were first identified in 2012. Prior to this, it is reasonable to expect that there will be learning disabled adults with a CHD2 disorder who have not been diagnosed. So far only a handful of adults in this country have been identified with CHD2.
In light of the recent advances in genetic testing, if you suspect that you or a person you know has an epilepsy condition with symptoms which are similar to those of CHD2 or an autism with epilepsy diagnosis, make an appointment with your GP to raise your concerns. You may wish to request a reassessment of your earlier diagnosis (if you were given one) and a referral to adult neurology.
Adult Neurology
A referral to Adult Neurology in your local or regional hospital will involve updating your medical history and possibly carrying out various tests. If your symptoms are similar to those of a CHD2 related disorder ask if they will make a referral to the regional genetic centre for testing.
Once you have received your diagnosis, it is important to be aware that regular appointments in adult neurology services are likely to be less frequent than in children’s services, often once a year. These will be followed up with regular Epilepsy Nurse specialist appointments to review medication and any other matters you wish to discuss. Epilepsy Nurse Specialists are available at any time to answer any questions you might have about your care and treatment.
Other NHS adult support services
If you feel you need support with routine medical procedures or advice regarding physical or mental health issues then there should be the equivalent of CAMHS in adult services known as the Learning Disability Health Support Team. This team will comprise dietitians, learning disability nurses, occupation therapists, physiotherapists, psychiatrists, psychologists and speech and language therapists.
An example of such a team within Bradford NHS Foundation Trust and what they provide can be found here: https://www.bdct.nhs.uk/services/learning-disability-health-support-team/
Definitions
Primary care – the day-to-day healthcare given by a health care provider, typically a general practitioner (GP), but can also include the community pharmacy, dentistry and eye care.
Secondary care – usually planned or elective care usually in a local hospital.
Tertiary care – highly specialist treatment usually found in a regional hospital, or specialist
CAMHS – Child and Adolescent Mental Health Services – the name for the NHS Services that assess and treat young people with emotional, behavioural or mental health difficulties.
ASD – Autistic Spectrum Disorder – the the medical name for Autism
ADHD – Attention Deficit Hyperactivity Disorder is a condition that affects people’s behaviour. People with ADHD can seem restless, may have trouble concentrating and may act on impulse.
PDA – Pathological Demand Avoidance Disorder – involves not being able to do certain things at certain times, either for yourself or others, it also refers to the things we do in order to avoid demands. More information can be found on the pdasociety.org.uk website.
EEG – an electroencephalogram is used to check for unusual electrical activity in the brain
MRI scan – magnetic resonance imaging helps spots problems in your brain that can sometimes cause epilepsy
CT scan – computed tomography, less frequently used than an MRI scan, which identifies any brain abnormalities
Ketogenic diet – A medical ketogenic diet is a very low carbohydrate, high fat diet which changes the metabolism in the body from burning glucose for energy to burning fat for energy. It is currently a recognised treatment for intractable (drug resistant) epilepsy.
VNS (vagus nerve stimulation) – is a treatment for epilepsy that involves a stimulator which is connected inside the body to the left vagus nerve in the neck. The stimulation sends regular, mild electrical stimulations through this nerve to help calm down the irregular electrical brain activity that leads to seizures (Epilepsy Society).