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| What is Hyperekplexia?
Hyperekplexia literally means exaggerated surprise and is the phrase now used to describe the combination of stiffness and startling that is seen primarily for the first time as a baby.
The startles are often in response to unexpected sounds, touching or sometimes sights. The stiffness is different person to person but tends to affect legs more than arms and can often affect the abdomen – sometimes this might make babies have breath-holding blue attacks.
The diagnosis can be made by a doctor recognising the pattern and excluding more common things (like startle epilepsy) and rare things (like paroxysmal extreme pain disorder). Sometimes stiffness and startle runs in families making the diagnosis easier to make. Most people have their diagnosis backed up with genetic testing which is offered in many places over the world including Swansea University (South Wales, United Kingdom).
There is still a great deal that we do not know about hyperekplexia – but with the help of affected families and their doctors we hope to produce some answers soon.
Can you explain, in non-medical terms, how the brain works to create the exaggerated startle?
The brain is controlled by a series of chemical networks - some make nerve cells fire, some make them less likely to fire. The glycine network is inhibitory - acting as a brake on the brain. When the glycine network is interrupted in hyperekplexia this brake is taken off and normal reflexes are more prominant.
We all startle and animals do too. Hedgehogs need to startle each and everytime so that they curl up into a ball and hide. Humans need to learn to startle the first time - check out the danger and then normally don't startle if threatened immediately afterwards. What am I saying? Hyperekplexia may be like being that hedgehog! I own a pygmy hedgehog called Heidi - she is quite hidey.
Why do we fall if we get startled from something unexpected and don't blackout?
The falls are not a form of epilepsy (even if some people do call them seizures). The falls are often a combined stiffening and startle all at once – producing a stumble and fall.
How rare is this condition?
I think we have to be honest about the scale of our society. I have details for around 60 people/families with hyperekplexia. Including all the world cases there may not be more than 200 and probably fewer than a thousand. We're a pretty small group – but we will meet a need for people.
Can you describe Clonazepam and other useful medications?
Clonazepam is the preferred medication to treat hyperekplexia. Some people find it helps startles more than the stiffness. It is a member of the benzodiazepine family – related to sleeping tablets like Temazepam, and anxiety tablets like Diazepam (Valium). It works more slowly and for longer than Valium and so is not addictive and doesn't give a "buzz'. However – as you can imagine – side effects include drowsniness and sleepiness.
Tips to help with this include changing the time of day that you take the tablets or trying to reduce the dose slightly. People often take these tablets twice a day, but they can also be taken just for weekends, or just for special days if the drowsiness is too difficult to stand.
Other patients have been helped by related drugs Nitrazepam and Chlordiazepoxide. Clobazam should also help. Animals who startle too much at fireworks get given L-tryptophan (the amino acid) – this has not been trialled in humans with hyperekplexia. Vigabatrin has been trialled, but should not now be used, due to the risks of retinal degeneration (and permanent tunnel vision).
Some people taking the benzodiazepine family of drugs after a number of years become "tolerant' to them. The best option is a "drug holiday' (a period of time away from that type of tablet) before they are reintroduced – hopefully to better effect.
Why does clonazepam sometimes fail to work after a number of years?
Some people taking the benzodiazepine family of drugs after a number of years become "tolerant' to them. The best option is a "drug holiday' (a period of time away from that type of tablet) before they are reintroduced – hopefully to better effect.
Does alcohol help adults with hyperexplexia?
Yes, some people report to having a good response to alcohol – reduced startling and stiffness. There is always the concern that people can become dependent on alcohol this way, so caution is needed. Patients are also cautioned not to mix alcohol and prescription medication.
What are early signs of Hyperekplexia?
Sometimes early signs can be seen as you wash, dress and feed an infant. Bath-time is typically when you might see startles. The classic test is to tap the bridge of the nose of a baby. Some babies startle even when you blow over their nose.
A note from Andy: Always look at premature newborns if they startle to unexpected tapping on their incubator, that's what my family did to me. As a newborn, I would not take any milk, and I would go stiff and rigid. I nearly drove my parents to a nervous breakdown.
Can affected babies stop breathing?
Yes. We think that stiffness in the tummy-muscles plays a big part in these attacks. Blue-breath holding attacks can be very serious in hyperekplexia and should not be managed at home. Parents can be taught a simple intervention called the Vigevano manoeuvre (flexing of the head and limbs toward the trunk) that counteracts the effects of stiffness in these breath-holding spells.
Is Hyperekplexia related to Cot Death (SIDS)?
This is unclear. There does seem to be an increased number of brothers and sisters of people with hyperekplexia who have cotdeaths (SIDS). Why this might be is unclear as these young children are thought not to have had the stiffness and startles. The blue-breath holding attacks however can be very serious and I know of some babies (not in the UK or USA) who have sadly died in these attacks.
What is the different between major and minor form of the condition?
This is unclear. Before there was any knowledge of the genes involved patients were classified as having major or minor forms of hyperekplexia. I no longer find this useful as the symptoms change over someone's life time, often in response to medication and can appear "minor' at 35 but were "major' at 1 year of age. There has not been any clear evidence that one gene causes major and another causes minor hyperekplexia.
Why do the doctors bang on the desk to make their patients jump? Hence, it's so funny ha ha.
All doctors used to be medical students and therefore have a bad sense of humor.
Patients can shake from head to toe and jerk and it feels like a panic attack. What causes this?
Well anxiety is also common in hyperekplexia – probably secondary to the frustration of the symptoms.
Is Hyperekplexia related to any other body malfunctions including erectile disfunction?
We really know very little about the complications of hyperekplexia. It seems not to affect fertility – however the drugs could cause sleep problems and even erection problems in some; as can alcohol of course.
Do your other patients have a tendency to be "night owls?"
This is certainly something that has never been looked at. If it is not related to the medication, then it might well be an important symptom that has been overlooked.
Do Hyperekplexia and Post Traumatic Stress Syndrome have any connection? Many PTSD websites talk about exaggerated startle responses.
Some anxiety conditions (PTSD is included here) involve exaggerated startle - but not stiffness so much.
Does Hyperexplexia pass on to the offspring during conception?
Hyperekplexia was, at first, thought to be autosomal dominant – which means that there is a fifty / fifty chance of passing the gene on. Although this is certainly the case for some – autosomal recessive inheritance is now more common. This means that a gene from Mum and a gene from Dad is needed to show the hyperekeplexia symptoms. There is obviously a higher risk of this happening when close family members marry.
What new tests are being done?
There are presently two main genes known to be involved and possibly more to be found. There are people at Swansea University looking back and searching in new places to find causes of hyperekplexia that starts from birth.
Very rarely the symptoms start later on in life. This can be as a result of an injury to a specific part of the brain (following an accident or a stroke perhaps) or in some isolated cases – perhaps by antibodies. We have contacts with Professor Angela Vincent's team at Oxford University who can perform these tests.
Do the tests involve taking blood and muscle from patients with the condition?
Normally blood tests for DNA are all that is needed. Muscle tests, brains scans and spinal fluid are often needed if the diagnosis is complicated. 
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