About rasmussen's syndrome
What is rasmussen's syndrome?
Rasmussen encephalitis, sometimes referred to as Rasmussen syndrome, is a rare disorder of the central nervous system characterized by chronic inflammation (encephalitis) of one hemisphere of the brain. As a result, the patient experiences frequent episodes of uncontrolled electrical disturbances in the brain that cause epileptic seizures (epilepsy). 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 cases 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.
What are the symptoms for rasmussen's syndrome?
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).
What are the causes for rasmussen's syndrome?
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 body’s 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.
What are the treatments for rasmussen's syndrome?
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.
What are the risk factors for rasmussen's syndrome?
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.
Is there a cure/medications for rasmussen's syndrome?
Various anti-seizure medications (anticonvulsants) may be prescribed to treat seizures. However, in most cases, 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 is the inevitable resultant 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 needs to be made jointly by the family and specialist center who deal with this condition regularly.