Startle disease

Startle Disease also known as Hyperekplexia is a rare, inherited neurological disorder characterized by pronounced startle responses. The term 'Hyperekplexia' is derived from the Greek words 'hyper' meaning excessive, and 'plexus' meaning braid. It was first described in the medical literature by Kirstein and Silfverskiold in 1958.

Symptoms

The primary characteristic of Startle Disease is an exaggerated startle response to unexpected stimuli, particularly loud noises. This startle response is followed by a temporary but complete stiffening of the body. During these episodes, individuals do not respond to any external stimuli. Infants with this disorder have an increased risk of sudden infant death syndrome (SIDS).

Causes

Startle Disease is caused by mutations in several genes including the GLRA1 gene, the GLRB gene, and the SLC6A5 gene. These genes are involved in the production of glycine, a neurotransmitter that is responsible for inhibiting nerve signals in the brain and spinal cord. Mutations in these genes result in a decrease in glycine signaling, leading to an over-excitation of the muscles and the characteristic startle response.

Diagnosis

Diagnosis of Startle Disease is based on the characteristic clinical features, a detailed patient history, a thorough clinical evaluation, and specialized tests such as genetic testing, which can detect mutations in the genes associated with this disorder.

Treatment

There is no cure for Startle Disease, but the condition can be managed with medications such as Clonazepam, which enhances the inhibitory effects of glycine in the nervous system.

Prognosis

With early diagnosis and appropriate management, individuals with Startle Disease can lead normal lives. However, without treatment, the disorder can lead to serious complications such as falls, injuries, and in severe cases, sudden death.

See Also

• Neurological Disorders
• Genetic Disorders
• Sudden Infant Death Syndrome

References

• Genetics Home Reference. (2018). Hyperekplexia. Retrieved from https://ghr.nlm.nih.gov/condition/hyperekplexia
• National Organization for Rare Disorders. (2018). Hyperekplexia. Retrieved from https://rarediseases.org/rare-diseases/hyperekplexia/