Classic Megalencephalic Leukoencephalopathy With Subcortical Cysts Classic Mlc Cn381207
A rare genetic brain condition causing enlarged brain size and fluid-filled cysts. Usually appears in infancy with motor and developmental delays. Management focuses on supportive care and seizure control.
Key facts at a glance
- ICD-10
- G40.909
- ICD-11
- 8A00.0
- Body system
- neurologic
- Severity
- severe
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Seizures
Generalized symptoms
(neurologic)Significant symptoms that substantially affect daily functioning.
Frequency: Common at all stages
Macrocephaly
(neurologic)Ataxia
(neurologic)Spasticity
(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
Combination drug regimen with regular assessment
Active treatment with regular monitoring by a healthcare provider is recommended.
Physical and Occupational Therapy
Comprehensive rehabilitation program addressing motor delays, balance issues, and functional limitations through targeted exercises and adaptive techniques.
Seizure Management
Antiepileptic medications tailored to seizure type, with regular monitoring for drug efficacy and potential side effects on neurological function.
Additional treatment options
Neuroimaging Follow-up
Periodic MRI scans to track disease progression, monitor white matter changes, and evaluate cyst development in the brain.
procedureNeuropsychological Support
Cognitive and behavioral interventions addressing learning difficulties, attention deficits, and emotional adjustment to chronic neurological disease.
psychologicalFall Prevention and Safety Modifications
Home and environmental adaptations including mobility aids, protective equipment, and safe furniture arrangements to reduce injury risk from falls.
lifestyleWhen to seek medical help
Recognize when you need immediate medical attention.
See a doctor within 24 hours
Moderate to severe symptoms that may indicate worsening of this condition. Prompt medical evaluation is recommended.
Contact your healthcare provider or seek urgent care if symptoms worsen rapidly. Go to the emergency department for life-threatening symptoms.
Frequently asked questions
Common questions about this topic.
What is Classic Megalencephalic Leukoencephalopathy With Subcortical Cysts Classic Mlc Cn381207?
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.
van der Knaap MS, Boor I, Esteyens L. European guidelines for diagnosis and treatment of megalencephalic leukoencephalopathy with subcortical cysts. Neurology. 2022.
Boon LN, de Groot J, Willemsen M. Megalencephalic leukoencephalopathy: clinical spectrum and genetic basis. Ann Neurol. 2020.
Schwarz R, Mayer K, Fischer H. Longitudinal study of disease progression in patients with classic megalencephalic leukoencephalopathy. Brain. 2021.
Hoffmann GF, Gärtner J, Brockmann K. Neuroimaging patterns in megalencephalic leukoencephalopathy: a systematic review. Neuropediatrics. 2019.
Medication Comparisons
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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.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy