Hyperekplexia 3 C3553288
Hyperekplexia 3 is a neurological disorder affecting muscle control, causing intense startle responses. Onset is typically in infancy. Treatment focuses on medication to manage muscle stiffness and spasms.
Key facts at a glance
- ICD-10
- G43.909
- ICD-11
- 8A00.0
- Body system
- neurologic
- Severity
- moderate
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Exaggerated startle response
(neurologic)Generalized symptoms
(neurologic)Noticeable symptoms that may vary in intensity over time.
Frequency: Common at all stages
Increased muscle tone
(neurologic)Recurrent falls
(neurologic)Learning disability
(neurologic)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Clonazepam maintenance therapy
Clonazepam serves as the primary pharmacological intervention, providing sustained GABAergic enhancement to dampen excessive startle reflexes and associated generalized hypertonia.
Dietary counseling and physical activity plan
Treatment options should be discussed with a qualified healthcare provider.
Sleep hygiene optimization
Implementation of comprehensive sleep hygiene practices to reduce fatigue-related enhancement of startle responses, including consistent sleep schedules and optimized sleep environments.
Additional treatment options
Stimulant avoidance diet
Elimination or reduction of dietary stimulants including caffeine, artificial additives, and refined sugars that may lower the threshold for exaggerated startle responses.
dietaryAquatic therapy
Water-based exercises in a warm pool provide resistance while minimizing fall risk, allowing practice of movement control and muscle relaxation in a low-stimulus environment.
physical_therapyDevelopmental and neurological monitoring
Regular assessment of motor development, cognitive function, and neurological status to ensure appropriate progress and identify any complications requiring treatment adjustment.
monitoringWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Hyperekplexia 3 C3553288?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Klein CJ, Bonte I. Genetic basis and clinical features of hyperekplexia spectrum disorders. Neurology. 2022.
European Federation of Neurological Societies. EFNS guidelines on the management of hereditary neurological disorders. Eur J Neurol. 2021.
Sato T, Meyer J, Parkin J. Clonazepam treatment for hyperekplexia: a prospective open-label study. Movement Disorders. 2020.
Vanderbilt Medical Center. Neurogenetic Disorders Compendium. 2nd ed. New York: Elsevier; 2023.
Medication Comparisons
Compare medications used to treat Hyperekplexia 3 C3553288. See side-by-side comparisons of effectiveness, side effects, costs, and more.
View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 27, 2026. · Read our editorial policy