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Rasmussen Syndrome

Enceph Rasmussen

Rasmussen syndrome is a very rare form of chronic and debilitating encephalitis that arises due to unihemispheric T-cell mediated inflammatory changes. Three clinical stages are described - a prodromal phase in which minor symptoms are seen, the active phase where drug-resistant seizures and a decrease in motor and cognitive function are prominent, and a residual stage in which neurological symptoms persist without further progression. Clinical criteria, electroencephalography (EEG), and magnetic resonance imaging (MRI) are necessary in order to make the diagnosis.


Rasmussen syndrome (commonly referred to as Rasmussen encephalitis) is a rare disorder of the central nervous system (CNS) [1] [2] [3] [4]. The exact pathogenesis remains unclear, but it is assumed that T-cell mediated reactions play a key role in inflammation and subsequent atrophy of one of the brain hemispheres [1]. The clinical presentation typically starts around the age of 6, and is divided into three distinct stages [1] [2] [3]:

  • Prodromal phase - The initial phase of the illness is characterized by the infrequent onset of seizures or hemiparesis that usually last up to several months, but reports show that years may pass before the next stage of illness ensues [1] [2].
  • Acute phase - All patients enter the acute stage of illness, whereas around 30% of individuals skip the prodromal phase [2]. Seizures appear in the form of epilepsia partialis continua - a type of simple partial, focal, and recurrent epilepsy that becomes quite frequent [1] [2] [5]. Additional findings include progressive hemiparesis, movement disorders, cognitive decline, as well as hemianopia and aphasia if the dominant hemisphere is affected by the disorder [1] [2] [6]. A growing number of studies have recognized that other types of focal seizures may emerge in the acute phase, all originating within the same hemisphere [1] [2].
  • Residual stage - After a relatively intense acute phase, the rate of neurological decline stabilizes, as do seizures, and a somewhat stable clinical course is observed [1] [2] [3].
  • In RE, the additional release gets lost over epilepsy duration.[dx.doi.org]
  • Yukitoshi Takahashi, Infections as causative factors of epilepsy, Future Neurology, 1, 3, (291), (2006).[oadoi.org]
  • Later, it progresses to paralysis of one side of the body (hemiparesis), blindness in one eye ( hemianopsia ), and loss of mental function.[encyclopedia.com]
  • Hemianopia or Hemianopsia which refers to a condition in which the person loses vision of one side of the visual field. Intellectual and cognitive difficulties such as of learning and memory etc.[epainassist.com]
  • This usually results in further weakness, hemianopsia and cognitive problems, but the other side of the brain may be able to take over some of the function, particularly in young children.[en.wikipedia.org]
Abdominal Pain with Urination
  • Seven years later, acute intermittent porphyria was diagnosed as she developed an acute episode of abdominal pain, dark urine, and hyponatremia.[ncbi.nlm.nih.gov]
Dark Urine
  • Seven years later, acute intermittent porphyria was diagnosed as she developed an acute episode of abdominal pain, dark urine, and hyponatremia.[ncbi.nlm.nih.gov]
  • As the seizures were refractory to valproate at 750 mg/kg/day, oxcarbazepine (OXC) at 30 mg/kg/day was added. Seizures became more frequent and on neurological examination, no hemiparesis was detected.[ncbi.nlm.nih.gov]
  • Permanent opening of Na channels by veratridine resembles maximal frequency of action potentials corresponding to epileptic seizures. These are preceded by a fall in [Ca 2 ] e.[dx.doi.org]
  • Seizures appear in the form of epilepsia partialis continua - a type of simple partial, focal, and recurrent epilepsy that becomes quite frequent.[symptoma.com]
  • Additional findings include progressive hemiparesis, movement disorders, cognitive decline, as well as hemianopia and aphasia if the dominant hemisphere is affected by the disorder.[symptoma.com]
  • The first was after an upper respiratory tract infection, the second was a post-complicated meningo-encephalitis and the third episode was associated with receptive aphasia, hemiparesis and intellectual impairment.[njcponline.com]
  • Language problems (aphasia) often occur if the disorder affects the side of the brain that controls most language functions, which is usually the left side. Who gets it? Rasmussen's syndrome usually begins between 14 months and 14 years of age.[epilepsy.com]
  • Presently, she has a dense right hemiparesis and severe global aphasia. Case 2 In 2001, a 44-year-old woman began having focal aware seizures characterized by episodic expressive aphasia.[frontiersin.org]
  • Loss of control over voluntary movements, loss of speech ability ( aphasia ), hemiparesis (weakness on one side of the body), dementia, mental retardation, and eventually, death, will follow if untreated.[encyclopedia.com]
Mental Deterioration
  • We describe a case of Rasmussen syndrome in a 7-year-old boy, presenting with epilepsia partialis continua, hemiplegia, and progressive mental deterioration.[ncbi.nlm.nih.gov]
  • RE is characterized by frequent and severe seizures, progressive loss of neurological functions including motor skills, speech, and eventual paralysis on one side of the body (hemiparesis), inflammation of the brain (encephalitis), and mental deterioration[ninds.nih.gov]
  • To be more precise, there are frequent and severe seizures (convulsions), progressive loss of motor skills and speech, hemiparesis (paralysis on one side of the body), encephalitis (inflammation of the brain), dementia , and mental deterioration.[medicinenet.com]
  • After 2 years, the patient was aphasic, hemiplegic, and mentally deteriorated, and seizures were refractory to antiepileptic drugs, corticosteroids, and alpha globulins. Plasmapheresis was of little benefit. [ 1 ] COMMENT.[pediatricneurologybriefs.com]
Cognitive Deficit
  • The clinical course throughout this time has been distinctly atypical for RS, with no progression in motor or cognitive deficits and rare secondarily generalized seizures.[ncbi.nlm.nih.gov]
  • However, most individuals with Rasmussen’s encephalitis are left with some paralysis, cognitive deficits, and problems with speech.[ninds.nih.gov]
  • The patient may present with frequent seizures, hemiparesis, and cognitive deficits. Throughout the disease’s course of about 8-12 months, further deficits can occur. However, in most cases, brain damage stabilizes.[gamma.wustl.edu]
  • Background: Rasmussen’s encephalitis (RE) is a rare inflammatory brain disease that causes intractable focal seizures, and progressive motor, sensory and cognitive deficits.[bri.ucla.edu]
  • Recognition of the syndrome, especially in pediatric populations, is difficult and often undiagnosed and/or confused with neurological disorders with similar clinical features.[ncbi.nlm.nih.gov]
  • It is not to be confused with a Rasmussen aneurysm. Most cases (85% cases) occur in children under the age of 10 years 1. However, detection in adults is increasing with routine MRI investigations for intractable seizures 5.[radiopaedia.org]
  • Symptoms Symptoms of RE may include: Severe partial seizures Loss of motor skills Loss of speech Paralysis on one side of the body Learning disabilities Physical disabilities Confusion The partial seizures may progress to seizures that happen nearly all[cedars-sinai.edu]
  • He was sleeping more, experience more confusion, and starting showing signs of a blood clot which was confirmed by a ct scan. He was moved to a step up unit so he could be more closely monitored. Again, Michael started to progress for a couple days.[gofundme.com]
  • Some affected children may exhibit degeneration (atrophy) of one side of the brain and/or progressive confusion, disorientation, and deterioration of intellectual abilities (dementia). Causes The exact cause of Rasmussen encephalitis is not known.[rarediseases.org]


Given the rare occurrence of Rasmussen syndrome in practice (a prevalence of approximately 0.18 per 100,000 individuals, and an incidence of 2.4 per 10 million individuals younger than 18 years of age), the diagnosis may be difficult to attain [1] [4], which is why physicians must obtain a detailed patient history and perform a thorough physical examination. The parents of the patient (especially if younger children are affected) could provide key information regarding the onset of symptoms and their severity. An additional challenge can be the highly variable course of Rasmussen syndrome, ranging from insidious and slowly progressive to rapidly ensuing and severely debilitating [6]. After an extensive neurological exam, electroencephalography (EEG) and magnetic resonance imaging (MRI) of the endocranium are recommended. EEG will show a unilateral pattern of slowed activity, whereas focal cortical atrophy, accompanied either by hyperintense signaling on T2-weighed or FLAIR images of the gray or white matter, or atrophy of the ipsilateral caudate head are main findings on MRI [1] [2] [7]. Unilateral ventriculomegaly is another hallmark of Rasmussen syndrome in the acute stage [1].

3 Hz Spikes
  • After initiating OXC daily, brief absence seizures, lasting less than 20 seconds and associated with bilateral and synchronous 2.5-3-Hz spike-and-waves compatible with typical absences, were observed.[ncbi.nlm.nih.gov]
Focal Spikes
  • The interictal EEG showed focal spikes and diffuse paroxysms in the right fronto-temporal regions. Brain MRI revealed right hemiatrophy, mainly at the Sylvian fissure.[ncbi.nlm.nih.gov]


  • PURPOSE: The aim of this study is to analyze the electroclinical features, treatment, and evolution of patients with Rasmussen syndrome (RS).[ncbi.nlm.nih.gov]


  • We confirm the unsatisfactory seizure control and the guarded neurological and intellectual prognosis that has been associated with Rasmussen syndrome.[ncbi.nlm.nih.gov]
  • In some very rare cases, the disease can progress to involve the opposite brain hemisphere. x Prognosis The prognosis for individuals with Rasmussen’s encephalitis varies.[ninds.nih.gov]
  • The prognosis (outlook) for individuals with Rasmussen's encephalitis varies. Untreated, the disorder may lead to severe neurological deficits including mental retardation and paralysis. In some patients the surgery decreases the seizures.[medicinenet.com]
  • Prognosis The prognosis for children below the age of 10 who are treated early in the course of the syndrome is good. This group can often achieve normal psychosocial and intellectual functioning.[encyclopedia.com]
  • […] cortical atrophy with ex-vacuo ventricular dilatation 15 T2: hyperintense signal areas in the affected hemisphere 15 DWI/ADC: restricted diffusion may be seen in altered signal areas 15 T1 C (Gd): no significant post-contrast enhancement 15 Treatment and prognosis[radiopaedia.org]


  • An etiology was not determined, but the disease was thought to be virally mediated. Many years later, the etiology remains elusive.[medlink.com]
  • We treated 19 patients with Rasmussen's syndrome (chronic encephalitis and epilepsy)--a rare progressive disorder of unknown etiology causing focal epilepsy, hemiparesis, and intellectual deterioration--with intravenous immunoglobulins, high-dose steroids[ncbi.nlm.nih.gov]


  • Epidemiology and clinical characteristics of seizures in patients with acute intermittent porphyria. Epilepsia. 1996 ;37: 230 - 235. Google Scholar Crossref Medline ISI Winkler AS, Peters TJ, Elwes Rdc.[doi.org]
Sex distribution
Age distribution


  • DISCUSSION: The present findings suggest that complex pathophysiologic mechanisms involving CD4( ) T cells and CD8( ) T cells change evolutionally during the progression of RS.[ncbi.nlm.nih.gov]
  • We speculate that cellular autoimmunity and the subsequent humoral autoimmunity against GluRɛ2 may contribute to the pathophysiological processes in Rasmussen's encephalitis.[oadoi.org]
  • Pathology of brain tissue shows changes of chronic encephalitis; the exact pathophysiology of this is unknown (previous studies implicating certain viruses have not been replicated), however there is sufficient evidence to support an autoimmune basis.[epilepsydiagnosis.org]


  • […] in Rasmussen encephalitis (RE) may be promoted by insufficient γ-aminobutyric acid (GABA) release. (3) H-GABA was released from neocortical synaptosomes through transporter reversal following intrasynaptosomal Na( ) accumulation by veratridine that prevents[ncbi.nlm.nih.gov]
  • Early diagnosis and treatment with immunoactive agents or hemispherectomy are sought to prevent the cognitive decline. A hypothesis of the pathogenesis is glutamate receptor autoimmunity associated with persistent viral infection (24).[asnr.org]
  • […] seizures in Rasmussen encephalitis (RE) may be promoted by insufficient γ‐aminobutyric acid (GABA) release. 3 H‐GABA was released from neocortical synaptosomes through transporter reversal following intrasynaptosomal Na accumulation by veratridine that prevents[dx.doi.org]



  1. Varadkar S, Bien CG, Kruse CA, et al. Rasmussen’s encephalitis: clinical features, pathobiology, and treatment advances. Lancet Neurol.. 2014;13(2):195-205.
  2. Bien CG, Granata T, Antozzi C, et al. Pathogenesis, diagnosis and treatment of Rasmussen encephalitis: a European consensus statement. Brain. 2005;128:454–471.
  3. Olson HE, Lechpammer M, Prabhu SP, et al. Clinical application and evaluation of the Bien diagnostic criteria for Rasmussen encephalitis. Epilepsia. 2013;54:1753–760.
  4. Bien CG, Tiemeier H, Sassen R, et al. Rasmussen encephalitis: Incidence and course under randomized therapy with tacrolimus or intravenous immunoglobulins. Epilepsia. 2013;54:543–545.
  5. Longaretti F, Dunkley C, Varadkar S, et al. Evolution of the EEG in children with Rasmussen’s syndrome. Epilepsia. 2012;53:1539–1545.
  6. Vining EP. Struggling with Rasmussen’s Syndrome. Epilepsy Curr. 2006;6(1):20-21.
  7. Yamazaki E, Takahashi Y, Akasaka N, Fujiwara T, Inoue Y. Temporal changes in brain MRI findings in Rasmussen syndrome. Epileptic Disord. 2011;13:229–239.

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Last updated: 2019-07-11 21:25