Encephalitis lethargica
Encephalitis lethargica
Encephalitis lethargica oror von Economo diseasevon Economo disease is an atypical form of encephalitis. Also is an atypical form of encephalitis. Also known as "sleepy sickness" (though different from the sleeping sickness transmitted by the known as "sleepy sickness" (though different from the sleeping sickness transmitted by the tsetse fly), it was first described by the neurologist Constantin von Economo in 1917. The tsetse fly), it was first described by the neurologist Constantin von Economo in 1917. The disease attacks the brain, leaving some victims in a statue-like condition, speechless and disease attacks the brain, leaving some victims in a statue-like condition, speechless and motionless. Between 1915 and 1926, an epidemic of encephalitis
motionless. Between 1915 and 1926, an epidemic of encephalitis lethargica spread around thelethargica spread around the world; no recurrence of the epidemic has since been reported, though isolated cases continue world; no recurrence of the epidemic has since been reported, though isolated cases continue to occur.
to occur. Symptoms Symptoms
Encephalitis lethargica is characterized by high fever, sore throat, headache, lethargy, double Encephalitis lethargica is characterized by high fever, sore throat, headache, lethargy, double vision, delayed physical and mental response, sleep inversion and catatonia. In severe cases, vision, delayed physical and mental response, sleep inversion and catatonia. In severe cases, patients may enter a coma-like state (akinetic mutism). Patients may also experience patients may enter a coma-like state (akinetic mutism). Patients may also experience abnormal eye movements ("oculogyric crises"), parkinsonism, upper
abnormal eye movements ("oculogyric crises"), parkinsonism, upper body weakness, muscularbody weakness, muscular pains, tremors, neck rigidity, and behavioral changes including psychosis. Klazomania (a vocal pains, tremors, neck rigidity, and behavioral changes including psychosis. Klazomania (a vocal tic) is sometimes present.
tic) is sometimes present.
Postencephalitic parkinsonism may develop after a bout of encephalitis, sometimes as long as Postencephalitic parkinsonism may develop after a bout of encephalitis, sometimes as long as a year after the start of the illness.
a year after the start of the illness. Cause
Cause
The cause of encephalitis lethargica is not
The cause of encephalitis lethargica is not known for certain.known for certain.
Research in 2004 suggested that the disease is due to an immune reaction. In this study, Research in 2004 suggested that the disease is due to an immune reaction. In this study, many of the people with encephalitis lethargica had experienced recent pharyngitis and the many of the people with encephalitis lethargica had experienced recent pharyngitis and the authors found some evidence linking the reaction to prior streptococcal throat. They authors found some evidence linking the reaction to prior streptococcal throat. They hypothesised that encephalitis lethargica, Sydenham's chorea and PANDAS (pediatric hypothesised that encephalitis lethargica, Sydenham's chorea and PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) are mediated autoimmune neuropsychiatric disorders associated with streptococcal infections) are mediated by variations of the
by variations of the post-streptococcapost-streptococcal immune response.l immune response. There is also some evidence of an
There is also some evidence of an autoimmune origin with antibodies (IgG) from patients withautoimmune origin with antibodies (IgG) from patients with encephalitis lethargica binding to neurons in the basal ganglia and mid-brain. Western encephalitis lethargica binding to neurons in the basal ganglia and mid-brain. Western immunoblotting showed that 95% of encephalitis lethargica patients had autoantibodies immunoblotting showed that 95% of encephalitis lethargica patients had autoantibodies reactive against human basal ganglia antigens. By contrast, antibodies reactive against the reactive against human basal ganglia antigens. By contrast, antibodies reactive against the basal ganglia were found in only 2-4% of
basal ganglia were found in only 2-4% of child and adult controls (n child and adult controls (n = 173, P < 0.0001).= 173, P < 0.0001). Some researchers believe that new data supports the influenza hypothesis, while others Some researchers believe that new data supports the influenza hypothesis, while others consider this less likely.
consider this less likely. Jang
Jang et al.et al. (2009) at St. Jude Children's Research Hospital, USA, discovered that a H5N1 Bird (2009) at St. Jude Children's Research Hospital, USA, discovered that a H5N1 Bird Flu (strain A/VN/1203/1204) infection in mice causes severe loss of tyrosine-hydroxylase Flu (strain A/VN/1203/1204) infection in mice causes severe loss of tyrosine-hydroxylase positive dopaminergic neurons 60 days after infection by
positive dopaminergic neurons 60 days after infection by provoking a destructive autoimmuneprovoking a destructive autoimmune response, thus suggesting the infection by certain strains of flu might increase the risk of response, thus suggesting the infection by certain strains of flu might increase the risk of Parkinson's disease in humans. While Jang
Parkinson's disease in humans. While Jang et al.et al. (2009) acknowledge research that shows the (2009) acknowledge research that shows the virus that caused the 1918 flu pandemic (a type A influenza subtype H1N1) unlike H5N1 Bird virus that caused the 1918 flu pandemic (a type A influenza subtype H1N1) unlike H5N1 Bird Flu did not infect the brain, they propose that a distal infection might have provoked an Flu did not infect the brain, they propose that a distal infection might have provoked an autoimmune mediated destruction of dopaminergic neurons, while leaving no direct evidence autoimmune mediated destruction of dopaminergic neurons, while leaving no direct evidence of brain infection.
Treatment for encephalitis lethargica in the early stages is patient stabilization, which may be Treatment for encephalitis lethargica in the early stages is patient stabilization, which may be very difficult. There is little evidence so far of a consistent effective treatment for the initial very difficult. There is little evidence so far of a consistent effective treatment for the initial stages, though some patients given steroids have seen improvement. Other patients have stages, though some patients given steroids have seen improvement. Other patients have been less fortunate, and the disease then becomes progressive, with evidence of brain been less fortunate, and the disease then becomes progressive, with evidence of brain damage similar to Parkinson's disease. Treatment is then symptomatic. Levodopa (L-DOPA) damage similar to Parkinson's disease. Treatment is then symptomatic. Levodopa (L-DOPA) and other anti-parkinson drugs often produce dramatic responses. However, in most of the and other anti-parkinson drugs often produce dramatic responses. However, in most of the patients who were given L-DOPA in the
patients who were given L-DOPA in the 1960s, the amelioration of the disease was short lived.1960s, the amelioration of the disease was short lived. The course of encephalitis lethargica varies depending upon complications or accompanying The course of encephalitis lethargica varies depending upon complications or accompanying disorders.
disorders.
The drug Zolpidem, commonly used as a sleeping pill, has been reported to be successful at The drug Zolpidem, commonly used as a sleeping pill, has been reported to be successful at treating encephalitis lethargic.
treating encephalitis lethargic. Salem witch trials
Salem witch trials
Historian Laurie Winn Carlson has advanced the idea that encephalitis lethargica is the Historian Laurie Winn Carlson has advanced the idea that encephalitis lethargica is the explanation for the symptoms of the afflicted in New England during the 17th century, which explanation for the symptoms of the afflicted in New England during the 17th century, which ultimately resulted in the Salem witch trials. Carlson writes: "By comparing the symptoms ultimately resulted in the Salem witch trials. Carlson writes: "By comparing the symptoms reported by seventeenth-century colonists with those of patients affected by the
reported by seventeenth-century colonists with those of patients affected by the encephalitisencephalitis lethargica
lethargica epidemic of the early twentieth century, a pattern of symptoms emerges [which] epidemic of the early twentieth century, a pattern of symptoms emerges [which] supports the hypothesis that the witch-hunts of New England were a response to unexplained supports the hypothesis that the witch-hunts of New England were a response to unexplained physical and neurological behaviors resulting from an epidemic of encephalitis."