Hyperekplexia is a rare movement disorder characterized by pathologically exaggerated response to unexpected stimuli. It is differentiated from the normal startle reflex by its lower threshold, higher intensity, and resistance to habituation. Many of the acquired hyperekplexias result from brainstem involvement such as encephalitis, infarct, hemorrhage, pontocerebellar hypoplasia and medullary ...

STARTLE is a basic alerting reaction common to all mammals. A rapid reflex not amenable to voluntary control, startle was studied extensively by Strauss in 1929,1 and is the subject of a 1939 monograph by Landis and Hunt2 and of a more recent study by Gogan.3 In the human adult, except for minor interpersonal variations, a stereotyped motor pattern is seen consisting of eye blinking; facial gri...

Hyperekplexia is a rare neurologic disorder, characterized by excessive startle response to unexpected stimuli. There are 3 cardinal features: generalized stiffness immediately after birth that normalizes during the first year of life; excessive startle reflex to unexpected (particularly auditory) stimuli; and a short period of generalized stiffness following the startle response while patient ...

BACKGROUND In addition to its role in cell adhesion and gene expression in the canonical Wingless/integrated Wnt signaling pathway, β-catenin also regulates genes that underlie the transmission of nerve impulses. Mutations of CTNNB1 (β-catenin) have recently been described in patients with a wide range of neurodevelopmental disorders (intellectual disability, microcephaly and other syndromic fe...

Hyperekplexia is a rare non-epileptic disorder characterized by an exaggerated and persistent startle reaction to the unexpected tactile and acoustic stimuli. The disorder is occasionally associated with generalized muscular rigidity and has the clinical hallmark of positive nose tapping test.The disease is inherited in an autosomal dominant fashion.  Recessively inherited and sporadic forms of...

hyperekplexia is a rare non-epileptic disorder characterized by an exaggerated and persistent startle reaction to the unexpected tactile and acoustic stimuli. the disorder is occasionally associated with generalized muscular rigidity and has the clinical hallmark of positive nose tapping test. the disease is inherited in an autosomal dominant fashion.  recessively inherited and sporadic forms o...

Coffin-Lowry syndrome (CLS) is an X-linked semi-dominant condition with learning difficulties and dysmorphism caused by mutations in the gene RSK2. Originally, epilepsy was reported as a feature. We and others have since described predominantly sound-startle induced drop attacks that have been labelled 'cataplexy', abnormal startle response and hyperekplexia. We sought to clarify why there shou...

We report a newborn with exaggerated startle reactions and stiffness of neonatal onset, the prototypical signs of hyperekplexia. Startle and flexor spasms, leading to apnoea, did not respond to treatment with clonazepam but did partially to sodium valproate. Molecular analysis of GLRA1 revealed no mutations. The incidental finding of hypouricemia led to a work-up for molybdenum cofactor (MoCo) ...