Trastornos paroxísticos no epilépticos neonatales / Non-epileptic paroxysmal disorder in neonates

Los trastornos paroxísticos no epilépticos son eventos frecuentes en el neonato, generalmente transitorios. Sin embargo, por su intensidad pueden ser confundidos como verdaderas crisis epilépticas. El objetivo de esta revisión es actualizar los conceptos en relación a los temblores, mioclonías neonatales benignas del sueño (MNBS) e hiperecplexia. Los temblores son muy frecuentes, una vez identificados debe determinarse si pertenecen a un síndrome de hiperexcitabilidad relacionado con factores maternos o perinatales, en casos idiopáticos se espera buen pronóstico. Las MNBS con frecuencia se confunden con crisis epilépticas, se caracterizan porque las mioclonías son breves y solo se presentan en el sueño, los niños son normales y el EEG también es normal. La hiperecplexia es un trastorno raro, genéticamente determinado, caracterizado por hipertonía y reacciones de sobresalto exagerado ante un estímulo banal, que pueden mejorar con clonazepam.

Non-epileptic paroxysmal disorders are frequent events in the neonate, generally transient. However, due to their intensity they can be confused as true epileptic seizures. The objective of this review is to update the concepts in relation to tremors, neonatal benign sleep myoclonus (MNBS) and hyperekplexia. The tremors are very frequent, once identified it must be determined if they belong to a hyperexcitability syndrome related to maternal or perinatal factors, in idiopathic cases a good prognosis is expected. MNBS are often confused with epileptic seizures. They are characterized by the fact that myoclonus is brief and occurs only in sleep, children are normal, and the EEG is also normal. Hyperekplexia is a rare, genetically determined disorder characterized by hypertonia and exaggerated startle reactions to a banal stimulus, which can be improved with clonazepam.

Familiar Hyperekplexia, a Potential Cause of Cautious Gait: A New Korean Case and a Systematic Review of Phenotypes

Familial hyperekplexia, also called startle disease, is a rare neurological disorder characterized by excessive startle responses to noise or touch. It can be associated with serious injury from frequent falls, apnea spells, and aspiration pneumonia. Familial hyperekplexia has a heterogeneous genetic background with several identified causative genes; it demonstrates both dominant and recessive inheritance in the α1 subunit of the glycine receptor (GLRA1), the β subunit of the glycine receptor and the presynaptic sodium and chloride-dependent glycine transporter 2 genes. Clonazepam is an effective medical treatment for hyperekplexia. Here, we report genetically confirmed familial hyperekplexia patients presenting early adult cautious gait. Additionally, we review clinical features, mode of inheritance, ethnicity and the types and locations of mutations of previously reported hyperekplexia cases with a GLRA1 gene mutation.

Novel GLRB gene mutation in a Saudi baby with hyperekplexia.

Aim: We aim to describe a case of hyperekplexia in a Saudi neonate due to Novel mutation in GLRB. Case Presentation: One month old Saudi neonate with hypertonicity, repetitive episodes of jitteriness and exaggerated startle reflex. Discussion: Hyperekplexia (OMIM:149400, 138492 & 604159) is considered a rare, autosomal dominant neurological disorder that presents early in life with hypertonicity, exaggerated startle response and life threatening neonatal apnea. It has been caused by mutation in the alpha-1subunit (GLRA1) on chromosome 5q32, Beta subunit (GLRB) gene on chromosome 4q31 of the inhibitory glycine receptor and GLYT2 gene (SLC6A5) on chromosome 11p15 which encodes a presynaptic glycine transporter. Conclusion: Raising awareness of the presence of this treatable disease may prevent unnecessary exposure to anti-epileptic medications, prevent life threatening apneas and improve long term outcome.

Sinus Node Paucity in Hyperekplexia.

We report a newborn with hyperekplexia and uncontrolled tonic spasms which did not respond to intravenous phenobarbitone and phenytoin, and midazolam infusion. Serum biochemistry, electrocardiography, electroencephalography, lumbar puncture and neuroimaging were normal. Continous cardiac monitoring revealed that tonic spasm episodes were accompanied by sinus node paucity and severe bradycardia. Duration and number of tonic spasm episodes decreased with clonazepam therapy, and she was discharged. At 4 months of age sudden infant death occured. Sudden infant death could be related to the paucity of sinus node. Cardiac pacemaker implantation should be considered even if the medical treatment is successful.

A Case Report of Congenital Hyperekplexia in Twin

Hyperekplexia or startle disease is a hereditary neurological disorder characterized by an abnormally exaggerated startle response to tactile, auditory and visual stimuli, together with a global muscular hypertonia and hyperactive tendon reflexes. This disease is a rare, genetically determined disorder, with an autosomal dominant inheritance with variable expression, first described by Suhren, et al. We report two cases of familial hyperekplexia, who developed hypertonia and pathologic startle response to tactile stimulation in the immediate neonatal period. The infant showed a marked improvement of the startle response and muscular hypertonia with low-dose clobazam.