Journal Identification = EPD Article Identification = 0999 Date: October 25, 2018 Time: 4:24 pm Clinical commentary Epileptic Disord 2018; 20 (5): 428-33 Diaper changing-induced reflex seizures in CDKL5-related epilepsy Roberta Solazzi 1, Elena Fiorini 1, Elena Parrini 2, Francesca Darra 1, Bernardo Dalla Bernardina 1, Gaetano Cantalupo 1 1 Child Neuropsychiatry, Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona 2 Laboratory of Neurogenetics, Pediatric Neurology Unit, Children’s Hospital A. Meyer, Florence, Italy Received March 26, 2018; Accepted July 22, 2018 ABSTRACT – Mutations in the CDKL5 (cyclin-dependent kinase-like-5) gene are known to determine early-onset drug resistant epilepsies and severe cognitive impairment with absent language, hand stereotypies, and decel- eration of head growth. Reflex seizures are epileptic events triggered by specific stimuli and diaper changing is a very rare triggering event, previ- ously described in individual cases of both focal and unclassified epilepsy, as well as in Dravet syndrome. Our aim was to describe diaper changing- induced reflex seizures as one of the presenting features in a case of CDKL5-related epilepsy, providing video-EEG documentation and focusing discussion on hyperexcitability determined by the disease. [Published with video sequence on www.epilepticdisorders.com] Key words: reflex seizure, diaper changing-induced reflex seizure, rub epilepsy, CDKL5-related encephalopathy CDKL5 is a gene located on chro- infantile spasms and myoclonic mosome Xp22, which encodes encephalopathy (Guerrini and cyclin-dependent kinase-like-5, a Parrini, 2012; Fehr et al., 2016). protein implicated in neuronal Reflex seizures are epileptic events development and morphogenesis, triggered by specific stimulation whose the precise functions remain (motor, sensory or cognitive), fre- unknown. Mutations in CDKL5 have quently occurring in association been largely described in patients with spontaneous seizures (Gastaut with early-onset drug-resistant and Tassinari, 1966; Striano et al., epilepsies and cognitive impairment 2012). Among the different types of with absent language, hand stereo- VIDEO ONLINE seizures, diaper changing-induced typies, and deceleration of head reflex seizures, although very rare, doi:10.1684/epd.2018.0999 Correspondence: growth (previously characterized as have already been described and are Roberta Solazzi “Rett-like” features). Focal seizures considered as a possible variant of Child Neuropsychiatry, are often the first presentation sensory reflex seizures. In particular, University of Verona, of the disease, with onset usually some authors suggested that diaper Pzz.le A. Stefani 1, 37126, Verona, Italy before five months of age. The changing-induced reflex seizures <[email protected]> epileptic phenotypes then include represent a subtype of the so-called 428 Epileptic Disord, Vol. 20, No. 5, October 2018 Journal Identification = EPD Article Identification = 0999 Date: October 25, 2018 Time: 4:24 pm Diaper changing-induced seizures “rub epilepsy” otherwise known as “rub-evoked reflex barbital led to only a reduction in seizure frequency epilepsy” (RERE) (Koul et al., 2016). and duration. Subsequently, reflex seizures disap- Only one patient with CDKL5-related epilepsy has pre- peared gradually and seizures continued to recur viously been reported to have reflex seizures (Saitsu only spontaneously, especially during drowsiness and et al., 2012). Our aim was to describe diaper changing- sleep. Since nine months, psychomotor delay and induced reflex seizures as initial clinical presentation midline stereotypies became evident. The interictal in a patient affected by CDKL5-related encephalopathy. EEG worsened progressively and since the age of 14 months, showed multifocal epileptic discharges, Case study becoming more frequent with eyes closed. At the same time, the patient started to present clusters of Our patient was the second child of non- spasms, apparently not associated with focal seizures. consanguineous parents, without a familial history of Treatment with a combination of clonazepam, pheno- epilepsy. Pregnancy was characterized by “placenta barbital, and valproate was followed by a two-month previa”, delivery occurred at term, and the perinatal seizure-free period, representing either a response period was unremarkable; at birth, auxological param- to AEDs or spontaneous remission (“honeymoon eters were normal and she had no feeding difficulties. period”). From the second month of life, the baby started pre- Next-generation sequencing analysis (using an senting with sudden isolated synchronous movements epilepsy gene panel with 109 genes) revealed a de of the lower limbs during feeding and diaper changing. novo frameshift mutation in the CDKL5 gene. The During sleep, she presented with paroxysmal events variant (c.580_581del) is considered pathogenic and characterized by eyes opening and lateral deviation of is not reported in either the literature or the Human the eyes, followed by diffuse stiffness and jerks of all Genetic Mutation Database (HGMD). four limbs. A first interictal EEG and brain MRI were normal. Treat- ment with carbamazepine was started with initial effi- Discussion cacy.At the age of three months, she started presenting with focal seizures, followed by a series of spasms (flex- The clinical course of our patient, characterized ion of the lower limbs and adduction of the upper by early-onset focal seizures, followed by progres- limbs) during diaper changing, several times a day. sion to epileptic encephalopathy with psychomotor She was hospitalised; psychomotor development was regression and drug-resistant epilepsy, as well as the normal (QG Griffith’s scale: 126) and only excessive occurrence of a seizure-free “honey-moon” period, startle reactions were evident on neurological evalua- is typical of CDKL5-related encephalopathy (Bahi- tion. Metabolic investigations were unremarkable. Buisson et al., 2008). Interictal EEG showed sporadic epileptic discharges in However, to our knowledge, there is only one bilateral centro-parietal regions, both during wakeful- published report of CDKL5-related encephalopathy ness and sleep (figure 1A, B). Furthermore, polygraphic with reflex seizures, which are described as mas- recordings revealed the presence of myoclonic jerks, sive myoclonic or generalized tonic seizures, induced asynchronous on right and left limbs (figure 1A, B); by light or phone (Saitsu et al., 2012). The particu- back-averaging analysis demonstrated the cortical ori- lar type of reflex seizure in our patient, induced by gin of the myoclonus (figure 1C, D). During EEG diaper changing, reflects a very rare condition and, recordings, we documented focal seizures induced to date, has never been described in CDKL5-related by diaper changing; the events clinically started with encephalopathy. In fact, this type of reflex seizure has staring, related to EEG rhythmic theta activity in centro- been described only in a few cases; one patient with parietal regions, followed by diffuse stiffness and focal epilepsy of unknown aetiology (Feyissa et al., rhythmic contractions of the four limbs, evolving into 2016), one with unclassified epilepsy associated with a series of spasms with predominant bending of the cerebellar hypoplasia (Koul et al., 2016), and a patient lower limbs (figure 2, video sequence). Spontaneous affected by Dravet syndrome (Subki et al., 2016). seizures with similar clinical and EEG features were Reflex seizures characterize either conditions in which recorded during sleep. During video-EEG monitoring, the epileptogenic area is limited and strictly related several attempts to evoke seizures by tactile stimula- to a triggering mechanism (e.g. somato-sensorial tion or by any other single manoeuvre involved diaper stimuli related to parietal cortical malformations) changing were unsuccessful. Additionally, we noticed (Gastaut and Tassinari, 1966; Striano et al., 2012), or a refractory period after seizures, during which it was conditions of diffuse cortical hyperexcitability (e.g. impossible to evoke them. Dravet syndrome, Rett syndrome). Regarding the Benzodiazepines provided a good response only latter, in Dravet syndrome, various triggers have been against isolated myoclonic jerks. Therapeutic attempts described, especially those inducing elevated body with topiramate and valproate were ineffective; pheno- temperature (Bureau and Dalla Bernardina, 2011); in Epileptic Disord, Vol. 20, No. 5, October 2018 429 Journal Identification = EPD Article Identification = 0999 Date: October 25, 2018 Time: 4:24 pm R. Solazzi, et al. AB F4-C4 C4-P4 P4-O2 T4-T6 T6-O2 Fz-Cz Cz-Pz F3-C3 C3-P3 P3-O1 T3-T5 T5-O1 R-delt R-ext R-flex R-quad L-delt L-ext 100 µV L-flex 1 sec L-quad CD C3 C3 50 µV 50 µV CZ CZ µ 50 V 50 µV C4 C4 µ 50 V 50 µV R-delt R-delt 50 µV 50 µV R-ext R-ext 50 µV 50 µV R-flex R-flex 50 µV 50 µV R-quad R-quad 50 µV 50 µV L-delt L-delt 50 µV 50 µV L-ext L-ext 50 µV 50 µV L-flex L-flex 50 µV 50 µV L-quad L-quad 50 µV 50 µV -1000 ms0 1000 ms -1000 ms0 1000 ms Figure 1. (A, B) Interictal EEG during sleep shows sporadic isolated spikes in the vertex region and both right and left centro-parietal regions, often related to single myoclonic jerks of the lower limbs (A) or upper limbs (B), asynchronous on the two sides. (C, D) Back- averaging of 30 different myoclonic events (trigger channel R-flex and L-flex, respectively): note that in both cases, there is evidence of agonist muscle co-contraction, followed by a contralateral