The clinical history of our patient has been characterized by the occurrence of the typical triad of West syndrome. The somatic abnormalities found in our patient suggested an additional diagnosis of “Hairy Elbows Syndrome”, a disorder with an unknown aetiology but frequently associated with intellectual disability and speech delay [8, 9].
At the time of diagnosis, the size increase of the left posterior hemisphere and the early psychomotor delay suggested a symptomatic aetiology of WS. Nevertheless, the quick and complete remission of spasms, never associated with other seizure types, the disappearance of hypsarrhythmic pattern, followed by an improvement of psychomotor development after ACTH treatment, and the seizure-free interval without EEG abnormalities during sleep and wakefulness until 12 years of age, resulted in a more favourable prognosis than that previously hypothesized.
In addition, the parents observed since the neonatal period a mild developmental delay but they did never detected a significant and/or enduring psychomotor regression beyond the remission of the spasms suggesting an “epileptic encephalopathy” [10].
Therefore, it is likely that the current intellectual disabilities represent mainly the developmental step of the early psychomotor delay, which in association with the structural brain abnormalities result from a congenital disorder.
The coexistence of the “Hairy Elbows Syndrome” and the West syndrome has never been reported. Thus, the relationship between the two syndromes need further investigations since even the molecular analyses, including ARX gene, mainly involved in brain development, were negative in our patient. However, the favourable clinical course, the lack of other seizure types, and the family history of recurrence of different age-dependent epileptic syndromes further weaken the link between WS and HES [2–4, 11] although a direct relationship between the two disorders can not be fully excluded.
The appearance at 12 years of age of myoclonic jerks of upper limbs synchronous with the typical generalized discharges of 4 Hz spike-wave, associated with uncomplicated clinical course, and the lack of other seizure types except the later GTCS, both sensitive to Levetiracetam, recalled an age-dependent epileptic syndrome.
We are prone to discern in the electroclinical feature of our patient, with the specific chronological sequence of the seizures above reported, the occurrence of the diagnostic criteria of JME recognized by the Classification of Epilepsies and Epileptic Syndromes [1] despite the abnormal brain MRI findings as brain lesions have previously been reported in patients with JME [12].
On the other hand the typical electroclinical phenotypes following the WS include focal and often secondarily generalized seizures and Lennox-Gastaut syndrome, whereas the myoclonic seizures associated with GTCS with late onset have not been described in previous follow-up studies [6].
However, from our point of view there is no obvious relationship between such presumed symptomatic spasms and JME, but it is striking to observe coexistence of two age-dependent epileptic syndromes in the same patient.
Recently, the transition between the more common age- dependent epilepsies has been documented and some overlapping pathophysiological processes and common genetic factors have been hypothesized [13].
Furthermore, the transition from WS to CAE has recently been described in two children [7]. Likewise, the clinical course of our patient might be read as a transition from an age-dependent epilepsy (WS) to another one (JME).
The linking between WS and the JME proves to be a complex relationship since to our knowledge common genetic alterations have not been reported in the literature.
As the variable etiology of infantile spasms, more than 200, lead to the same electroclinical feature it has been speculated that different clinical conditions may converge on a final common pathway [14]. In agreement with this view, it has been recently hypothesized that some types of epilepsy, including WS and JME, may depend on the dysfunction and on a specific susceptibility of a given neural system to epileptogenic factors (system epilepsy) [15].
It is likely that some genes other than those currently known or non-conventional genetic influences such as epigenetic, or environmental factors play a role in seizure predisposition.
Therefore, the co-occurrence of WS and JME in our patient may depend on the dysfunction of specific brain systems which to some extent overlap or influence each other. Thus, the usual occurrence of the seizures during periods of sleep-wake transitions in both syndromes may be a clinical trait of a common dysfunction present in WS and JME. Of course, future studies of functional neuroimaging could help to understand these relationships.