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Last updated: 02/08/2023
Years published: 1987, 1989, 1994, 1995, 1997, 1998, 2006, 2009, 2012, 2016, 2019, 2023
NORD gratefully acknowledges Gary W. Mathern, MD, Professor and Neurosurgical Director, Pediatric Epilepsy Surgery Program, Departments of Neurosurgery and Psychiatry & Biobehavioral Medicine, Mattel Childrenโs Hospital, David Geffen School of Medicine, UCLA; William Davis Gaillard, MD, Professor, Pediatrics and Neurology, George Washington University School of Medicine, Professor Neurology, Georgetown University, Chief, Epilepsy, Neurophysiology, and Critical Care Neurology, Childrenโs National Medical Center, Associate Director, Center for Neuroscience Research, Childrenโs Research Institute; Prof. J. Helen Cross, The Prince of Walesโs Chair of Childhood Epilepsy UCL-Institute of Child Health, Great Ormond Street Hospital for Children & Young Epilepsy and Head of Neurosciences Unit, UCL-Institute of Child Health, London, for assistance in the preparation of this report.
Rasmussen encephalitis, sometimes referred to as Rasmussen syndrome, is a rare disorder of the central nervous system characterized by chronic progressive inflammation (encephalitis) of one cerebral hemisphere. As a result, the patient usually experiences frequent episodes of uncontrolled electrical disturbances in the brain that cause epileptic seizures (epilepsy) and progressive cerebral destruction. With time, further symptoms may include progressive weakness of one side of the body (hemiparesis), language problems (if on the left side of the brain) and intellectual disabilities. The exact cause of this disorder is not known. The two leading ideas are that the brain inflammation might be a reaction of a foreign antigen (infection) or an autoimmune disease limited to one side of the brain resulting in brain damage. It occurs mostly, but not always, in children between the ages of two and ten years, and in many patients the course of the disease is most severe during the first 8 to 12 months. After the peak inflammatory response is reached, the progression of this disorder appears to slow or stop, and the patient is left with permanent neurological deficits.
Typically, affected individuals develop focal seizures that may progress to near continuous seizures termed epilepsia partialis continua (EPC). EPC is characterized by a rapid, rhythmic succession of contractions and relaxations of a muscle or muscle group (myoclonus), particularly of the arms, legs, and face, that may occur singularly or in a repetitive, continuous series. In Rasmussen this occurs consistently on one side of the body opposite the side of the inflammation.
Most affected children will exhibit progressive paralysis of one side of the body (hemiparesis) and if the seizures continue developmental disabilities. In many cases, the development of physical and mental abilities of affected children may cease (developmental arrest). In addition, affected children may lose previously acquired physical and mental abilities (developmental regression). Some affected children may exhibit degeneration (atrophy) of one side of the brain and/or progressive confusion, disorientation and deterioration of intellectual abilities (dementia).
The exact cause of Rasmussen encephalitis is not known. Most researchers now suspect that Rasmussen encephalitis is an autoimmune disorder following histopathologic review of the tissue involved under the microscope. In autoimmune disorders, the bodyโs natural defenses (antibodies and T-cells) fight its own tissue, mistaking it for foreign organisms for no apparent reason.
Some researchers believe that Rasmussen encephalitis may be triggered by an unidentified infection such as influenza, measles or cytomegalovirus.
Rasmussen encephalitis mostly affects children ten years of age and younger. It is unusual to affect children under two years of age. Adolescents and young adults in much smaller proportions are also affected. There may be a history of some prior mild cold or flu prior to the onset of the seizures. The annual number of new-onset Rasmussen has been estimated as 2.4/10,000,000 persons less than or equal to 18 years of age.
Rasmussen encephalitis may be diagnosed clinically based upon a thorough clinical evaluation, a detailed patient history, and a complete neurological evaluation including advanced techniques such as electroencephalography (EEG) and magnetic resonance imaging (MRI).
During an EEG, the brainโs electrical impulses are recorded. Such studies may reveal brain wave patterns that are characteristic of certain types of epilepsy. During MRI, a magnetic field and radio waves are used to create cross-sectional detailed images of the brain. It is usual that the diagnosis is made after a minimum of two scans which will detail progressive shrinkage of the affected side of the brain.
Treatment
Treatment of Rasmussen encephalitis is mostly symptomatic and supportive. Special services that may be beneficial to affected children include special social support, physical therapy and other medical, social, and/or vocational services.
Various anti-seizure medications (anticonvulsants) may be prescribed to treat seizures. However, in most patients, anticonvulsants have proven ineffective. Medical treatments targeted at possible autoimmune disease may be tried, including steroids, immunoglobulin and tacrolimus. Immunological therapies (tacrolimus, intravenous immunoglobulins, potentially others as well) may slow down the neurological and structural deterioration but usually does not improve the epilepsy or progressive brain atrophy. Its precise role in management of Rasmussen encephalitis remains to be determined.
Surgery usually in the form of a cerebral hemispherectomy is the only way to cure the seizures and halt neurodevelopmental regression. However, there are inevitable functional deficits including hemiparesis (weakness of one side) and hemifield defect (impairment of vision to one side), and where the dominant side of the brain is affected, there may be an effect on language. The difficulty is often deciding on the necessary and best timing of surgery, dependent on the severity of epilepsy and degree of effect on learning and progression of the disease. The decision should be made jointly by the family and specialist center that has experience treating patients with this condition.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Toll-free: (800) 411-1222
TTY: (866) 411-1010
Email: [email protected]
Some current clinical trials also are posted on the following page on the NORD website:
https://rarediseases.org/living-with-a-rare-disease/find-clinical-trials/
For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com
For information about clinical trials conducted in Europe, contact
https://www.clinicaltrialsregister.eu/
Contacts for additional information about Rasmussen encephalitis:
Gary W. Mathern, MD
The Davies endowed Chair for Epilepsy Research at UCLA
Professor and Neurosurgical Director, Pediatric Epilepsy Surgery Program
Departments of Neurosurgery and Psychiatry & Biobehavioral Medicine
Mattel Childrenโs Hospital
David Geffen School of Medicine
University of California, Los Angeles
Telephone: 310-825-7961
Fax: 310-825-0922
Email: [email protected]
William Davis Gaillard, MD
Professor, Pediatrics and Neurology
George Washington University School of Medicine
Professor Neurology
Georgetown University
Critical Care Neurology
Childrenโs National Medical Center
Associate Director, Center for Neuroscience Research
Childrenโs Research Institute
Telephone: 202-476-2120
Email: [email protected]
Prof. J. Helen Cross
The Prince of Walesโs Chair of Childhood Epilepsy UCL-Institute of Child Health, Great Ormond Street Hospital for Children & Young Epilepsy
Head of Neurosciences Unit
UCL-Institute of Child Health
4/5 Long Yard
London WC1N 3LU
Telephone number: 0207 599 4105
Fax Number: 0207 430 0032
Mobile: 07983420692
email: [email protected]
Anne Brown, PA
The Neville Epilepsy Centre
Young Epilepsy
email: [email protected]
Louise Jones, PA
Young Epilepsy
Tel: 01342 831212
email: [email protected]
www.youngepilepsy.org.uk
JOURNAL ARTICLES
Kruse CA, Pardo CA, Hartman AL, โฆand Mathern GW. Rasmussen encephalitis tissue transfer program. Epilepsia. 2016; 57:1005โ1007. doi: 10.1111/epi.13383
Varadkar S, Bien CG, Kruse CA, Jensen F, Bauer J, Pardo CA, Vincent A, Mathern GW, and Cross HJ. Rasmussenโs encephalitis: present understanding and treatment advances. The Lancet-Neurology, 2014;13:195-205. PMID: 24457189
Bien CG, et al. Rasmussen encephalitis: incidence and course under randomized therapy with tacrolimus or intravenous immunoglobulins. Epilepsia. 2013 Mar;54(3):543-50.
Owens GC, Huynh M, Chang JW, McArthur D, Hickey MJ, Vinters HV, Mathern GW, and Kruse CA. Differential expression of interferon-ฮณ and chemokine genes distinguishes Rasmussen encephalitis from cortical dysplasia and indicates an early Th1 response. Journal of Neuroinflammation, 2013;May 2;10:56. doi: 10.1186/1742-2094-10-56. PMID: 23639073.
Bauer J, Vezzani A, Bien CG. Epileptic encephalitis: the role of the innate and adaptive immune system. Brain Pathology. 2012:22(3):412-21.
Bien CG, Granata t, Antozzi C, et al. Pathogenesis, diagnosis and treatment of Rasmussen encephalitis: a European consensus statement. Brain. 2005:128, 454-71.
Koh S. Mathern GW, Glasser g, et al. Status ellipticus and frequent seizures: incidence and clinical characteristics in pediatric epilepsy surgery patients. Epilepsia. 2005;46:1950-54.
Korkman M, Granstrom ML, Kantola-Sorsa E, et al. Two-year follow-up of intelligence after pediatric epilepsy surgery. Pediatr Neurol. 2005;33:173-78.
Gaynor Y, Freilinger M, Dulac O, Levite M. Monozygotic twins discordant for epilepsy differ in the levels of pathogenic antibodies and cytokines. Autoimmunity.2005;38:139-50.
Freeman JM. Rasmussenโs syndrome: progressive autoimmune multi-focal encephalopathy. Pediatr Neurol. 2005;32:295-99.
Tubbs RS, Nimjee SM, Oakes WJ. Long-term follow-up in children with functional hemispherectomy for Rasmussenโs encephalitis.Childs Nerv Syst. 2005;21:461-65.
Hart Y. Rasmussenโs encephalitis. Epileptic Disord. 2004;6:133-44.
INTERNET
NINDS Rasmussenโs Encephalitis Information Page. National Institute of Neurological Disorders and Strokes. National Institutes of Health. Last reviewed on July 25, 2022. https://www.ninds.nih.gov/health-information/disorders/rasmussens-encephalitis Accessed Dec 7, 2022.
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Learn more https://rarediseases.org/patient-assistance-programs/caregiver-respite/The information provided on this page is for informational purposes only. The National Organization for Rare Disorders (NORD) does not endorse the information presented. The content has been gathered in partnership with the MONDO Disease Ontology. Please consult with a healthcare professional for medical advice and treatment.
The Genetic and Rare Diseases Information Center (GARD) has information and resources for patients, caregivers, and families that may be helpful before and after diagnosis of this condition. GARD is a program of the National Center for Advancing Translational Sciences (NCATS), part of the National Institutes of Health (NIH).
View reportOrphanet has a summary about this condition that may include information on the diagnosis, care, and treatment as well as other resources. Some of the information and resources are available in languages other than English. The summary may include medical terms, so we encourage you to share and discuss this information with your doctor. Orphanet is the French National Institute for Health and Medical Research and the Health Programme of the European Union.
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