24 September 2019
A NEW SCIENTIFIC PUBLICATION REGARDING AHC
Editorial comment written by the Scientific Coordinator of the IAHCRC Consortium, Prof. Mohamad Mikati, to the article about the epileptology of Alternating Hemiplegia of Childhood that he recently published in the Scientific Journal NEUROLOGY.
"In a study of 51 consecutive AHC patients at Duke University, the Duke team found the following:
- That 63% of that group of AHC patients had epilepsy and that epilepsy was either of focal origin or generalized origin. Specifically, more than half seizures of focal onset and over 1/3 had seizures of generalized onset.
Significance: This is important since the choice of the correct medication depends on the type of seizure and indicates that physicians taking care of AHC patients should determine first the type of epilepsy before deciding on the choice of which anti-epilepsy medication to choose.
- In 14% of the patients, the epileptic seizures even preceded the hemiplegic and dystonic manifestations.
Significance: the occurrence of epileptic seizures should not lead to neglecting the symptoms of AHC which could lead physicians to miss or delay making the diagnosis of AHC.
- EEG studies were helpful but often were normal even after the epileptic seizures had already started.
Significance: If epilepsy is suspected and the EEG is normal, repeating the EEG would be important since there was a lag of about 3-4 years in many patients before the EEG showed epileptic activity.
- In addition to the dystonia and hemiplegia spells most patients with AHC have episodes that can be confused with epileptic seizures consisting of staring and decreased responsiveness without any concurrent epileptic EEG change. These were termed Reduced Awareness Spells (RAS).
Significance: These spells should not be misdiagnosed as epileptic seizures as this would lead to needless use of anti-epilepsy drugs. If RAS are suspected then these can be distinguished by capturing them on video or concurrent video EEG or by their lack of typical manifestations that accompany epileptic seizures.
- For patients whose epileptic seizures did not respond to medications the Duke team found that most of those patient had marked reductions in their seizures using vagal nerve stimulation (VNS).
Significance: AHC patients with drug resistant epileptic seizures need to be considered to receive the VNS therapy
- Twelve of the 32 patients with epilepsy (lightly over 1/3) had one more prolonged severe epileptic seizures (status epilepticus). Four of these regressed neurologically due the status.
Significance: This emphasizes the importance of detecting epileptic seizures and treating them quickly to prevent occurrence of status and the complications that can follow it."
You can read the abstract and download the full article at this link.