FAQs · Neurology

Just out of the blue, a few days ago, our 5-year-old grandson had what we thought was a seizure. He had three or four on that day. He’s been booked in for an EEG as they are suspecting epilepsy. Because he has Noonan Syndrome, are there any other possible causes for the seizures? Is it different to the general population? Should we be considering other causes?

We certainly have seen a slight increase in seizures with Noonan Syndrome. They don’t seem to have a particularly different pattern from some of the other epilepsy we have but maybe we could have some general points about how we diagnose and treat epilepsy. It is important to note that sometimes it can be difficult to distinguish a seizure from a fainting episode that’s caused by an abnormal heart rhythm. It’s unlikely to be that but a heart rhythm abnormality is one of the things that need to be thought about and having an ECG should be part of the investigation. The ECG would look at the electrical activity in the heart, the EEG is looking at the electrical activity in the brain in an identical manner and seeing if there are any sporadic intermittent changes that we would associate with the seizure activity.

Sometimes we need a prolonged EEG to pick up those episodes and if he’s only just presented, perhaps with a little cluster of these funny episodes, it’s not unusual that perhaps we miss them with an isolated EEG. It’s useful if we can capture the clinical episode with the electrical changes that we see. Sometimes imaging of the brain will be helpful as well as there are some different brain structures that can contribute to epileptical activity.

There are lots of things that being under a general paediatrician with an interest in neurology or a paediatric neurologist would be very helpful from that point of view. They would need to look at what the movements are like, how they present; there’s a lot of information they can pick up from that as well. Structural, electrical, all need to be looked at but don’t forget other causes for the fits, faints and funny turns, as we call them. One of the things that we found useful, and it doesn’t sound a very pleasant thing to have to do, but OK if you do it in the privacy of your own home, was to take a short film of what was happening because an experienced epilepsy consultant can tell a lot from that. So if the circumstances allow and the person is being looked after well, if someone else can take a film on their phone, that can be very valuable to an epilepsy consultant.

We have a son in his 30s who has NS and was born profoundly deaf. Has there been any recent research into connection between the two?

Noonan syndrome with multiple lentignes or freckles (previously known as LEOPARD syndrome) has deafness as a feature and so we know that deafness may be associated with the PTPN11 gene. In most cases deafness in Noonan syndrome will simply be due to glue ear but it may be due to nerve deafness. There has not been much research on the nerve deafness in Noonan syndrome.

Is it common to have an issue with a child regulating his body temperature—starting to go blue after 5 minutes swimming but so hot in bed at night he can hardly be touched?

The issue with body temperature is seen in neurological conditions such as CFC and Costello and sweating seems to be quite common in Noonan Syndrome but it does seem to diminish with age.

Is a child’s auditory neuropathy (hearing loss in which the outer hair cells within the cochlea are present and functional, but sound information is not faithfully transmitted to the auditory nerve and brain properly) a result of having Noonan Syndrome?

Some children with Noonan Syndrome have problems with hearing, most commonly “glue ear”. It’s possible that the child’s condition was linked to Noonan Syndrome but more information was needed. There were genetic tests which should be able to tell if the condition was linked causally. People with Leopard Syndrome, closely related to NS, often suffered hearing problems.