Encephalitis lethargica (Narcolepsy) A detailed Overview)

This article will highlight the disorder of Encephalitis lethargica. 

This article will contain all the necessary information that will help understand the Encephalitis lethargica, and you will get a clear picture of this disorder.

This is commonly a neurological disorder, and since the early 19 century, this disorder has been coming on.

The disorder of Encephalitis lethargica is a symptom of neurology, and that is mainly spread in Europe.

Now people from all over the world are found in suffering from this disease.

According to the clinical presentation, this disorder is characterized by the chronic and acute phrase, and these two different conditions are blended.

What is Encephalitis lethargica?

The other name of this Encephalitis lethargica disease is Von Economo disease.   

Encephalitis lethargica is a disorder that is rare and serious. This disease was found in the early 16th century, and it was commonly found in European countries.

As the phenomenon of the past, this disease was regarded a few years back. Encephalitis lethargica is known as a mysterious disease.

This disease is mainly referred to as sleeping sickness. 

Encephalitis lethargica is mainly evolved to have different kinds of infestations that were primarily characterized by movement disorder and insomnia.

In an acute stage, Encephalitis lethargica was mainly characterized by intractable somnolence.

And then it mostly attributed to different types of abnormalities of the diencephalon.

This disease of Encephalitis lethargica also described some significant conditions that include double vision, slow mentally, physical response, and feeling extremely tired. 

In the subcortical brain, the patient tends to sleep.

From the idiopathic Parkinson disease, when we differentiate some of the points that include the onset of younger age, altered sleep-wake cycle, and oculogyric crisis.

There are different survivals of Encephalitis lethargica found with sequelae of neurology permanently, and they were akinetic completely.

Some of the significant essential points of Encephalitis lethargica are mentioned as below.

  • The disorder of Encephalitis lethargica is considered as acute polio-encephalitis of broad etiology that is unknown.
  • The disorder of Encephalitis lethargica can be clinically diagnosedWith the acute case, the crises of oculogyric are not associated during the period of epidemic. 
  • From influenza, there is no direct link of data with Encephalitis lethargica.by using some data and clinicians. There is a link that is supposed to be with it. 
  •  Patients are suffering from Encephalitis lethargica experience sleepiness excessively, which is the disorder of ocular motility. Movement disorders and feel like having a fever. Any other neurological symptoms and signs can be exhibited. The conditions and symptoms can be changed every day or every hour. According to the recent reports, half of million or might be a million people or more were affected by Encephalitis lethargica, one-third of them died. 

Unlike Encephalitis Lethargica, there is a neurological disorder/issue, called the Cortical Spreading Depression.

But it too is caused mostly due to biological factors.

Causes of Encephalitis lethargica

The origins of Encephalitis lethargica are unknown. It is an acute viral or posts of a viral syndrome.

The objectives of these diseases were never found scientifically, and it is still considered as a controversy until today.

The research has suggested that Encephalitis lethargica, is mainly occurred as a result of a reaction of immune to streptococcal reaction.

According to the studies that this condition might be autoimmune is the origin.

That is what has made diagnosis difficult, and that is why the information related to the causes of Encephalitis lethargica is still lacking.

There are such difficulties found in treating this disorder. There are no such cases found related to Encephalitis lethargica. 

The suspected cases of Encephalitis lethargica should be tested for the receptor of NMDA encephalitis. 

Signs and symptoms

Some of the signs like parkinsonian can show it.

Some of the other common symptoms of this disorder include a slight fever and minor flu, headache, shivering without any reason, vomiting pharyngitis, and vertigo.

The symptoms of neurology can occur, and it could be presented quickly.

Some of the common symptoms of Encephalitis lethargica disorder are mentioned as under.

  • ∙ High fever
  • ∙ Sleep inversion
  • ∙ Sore throat
  • ∙ Muscle pains
  • ∙ Headache
  • ∙ Double vision
  • ∙ Delayed responses, both physically and mentally
  • ∙ Lethargy
  • ∙ Catatonia or unresponsiveness
  • ∙ In severe cases, a patient may enter a state resembling coma called akinetic mutism
  • ∙ Tremors
  • ∙ Abnormal eye movements called oculogyric crises
  • ∙ changes including psychosis
  • ∙ Weakness in the upper body
  • ∙ Vocal tic called kleptomania
  • ∙ Neck rigidity

Those who survive from Encephalitis lethargica mostly develop a form of parkinsonism that is called post-encephalitic Parkinson’s.

This mainly results in a severe disability of neurology. This includes an example like a girl who was suffering from this Encephalitis lethargica disorder going to a concert she suddenly hemiplegia.

She went to sleep after half an hour and died after 12 days. The acute Encephalitis lethargica is classified in three different forms that include:  


The Somnolent-ophthalmoplegic is a form of Encephalitis lethargica that is very common and a prodromal symptom. 

The patient becomes confused, stunned, and excited. Sometimes this disorder exhibits irritation meningeal that is mild. 

Some other standard features of this disorder are Cranial nerve palsies that affect the nerves, particularly that mainly result in pupillary and ophthalmoplegia abnormalities.

The most notable thing about this disorder is that patients mostly experience an overwhelming desire for sleep.

When they sleep, they mostly kept on sleeping for such a long period. 

It is easy to awaken them, and they can remember everything that had happened before sleeping.

The rate of mortality of Somnolent-ophthalmoplegic is higher as compared to other forms of Encephalitis lethargica, and the price is exceeding 50%.


This is a common and specific disorder of behavior found in children. This disorder is caused due to the disease of organics.

This is characterized by hyperactivity. The initial manic phase is presented in this hyperactivity form of Encephalitis lethargica.

The patient will often experience, vocalizations, myoclonic twitches, chorea, and dysrhythmia of the ocular and masticatory muscles.

The manic phase was mainly followed by generalized fatigue, weakness, and restlessness that is persisted for a few days.

During this phase of hypomanic, the neurologic pain is experienced by the patient in the limbs and face and the reversal of the day-night sleep cycle. 


This disorder is mainly a form of Encephalitis Lethargica, and it is least common among people.

The patient in this disorder get movements, and there is no such noticeable weakness found, and these patients also experience rigidity. 

For altering their posture, these patients are prolonged, and there were such movements that were minimal.

For an extended period, the patient remains immobile and rigid, but the rigidity can be overcome by doing external force slightly. 

Patients become mentally intact, but there are such emotions that are hardly noticeable on masked faces.

The possibility of recovery is rapid and slow. It depends, and this condition might last for several months as well.

After the acute phase, the Encephalitis lethargica typically develops in 1 to 5 years.it can be followed immediately or might take a few years. 

Parkinsonism mainly characterized the chronic phase.

Still, some other features are also notified and found commonly in people that include sleep disturbances, psychiatric disorders, oculomotor abnormalities, speech, and respiratory abnormalities, involuntary movements, etc.

Diagnostic aspects

It is challenging to diagnose Encephalitis lethargica, and in many countries, there is a lack of statistical records.

It mainly means that you cannot estimate the number of causes. The age limit that gets affected by this disease is from 30 to 40. 

Risk Factors of Encephalitis lethargica

There are no such risk factors of Encephalitis lethargica have been found clearly that helps in identifying the disease.

The main thing that matters or it’s important is that getting to know the risk factors of a disease does not mean that you are going to know the exact condition.

The meaning of risk factor is that one will get a chance of getting into a specific situation, which is directly compared with an individual without any risk factor. 

Sometimes risk factors are critical to know to prevent the disease.

If there is no risk factor, it does not means that the individual is not suffering from that specific disease.

Discussing the risk factors is always very important, so it will help in giving the right medication and helps the patient in curing the infection quickly. 

Treatment of Encephalitis lethargica

There are many symptoms of Encephalitis lethargica disease that are similar to the symptoms of Parkinson’s disease.

The medications of antiparkinson, like Levodopa, can be useful in treating the condition of Encephalitis lethargica. 

For managing the patients of Encephalitis lethargica, there is a sleeping pill named Zulfidem is very useful for these patients as well. 

Helpful Sources

  1. If you want to learn complete detail about the disease so read

Link 1

  1. Conditions faced by the patients of

Link 2


In this article, we have concluded that Encephalitis lethargica. Is related to neurological disease.

There are no such risk factors of this disease, but there are numerous symptoms of this disease, which you can see in the article.

When it comes to treatment, there are different medications used for treating this disease as it is related to some other conditions of neurology, so the anxiety medicine and sleeping pill can efficiently work.

This disease is prevalent, but there are no such causes of this disease have been appearing.

The research is still going on to get better treatments for patients. 


Is encephalitis Lethargica still around?

Yes since 1 century this disease is still found.

The maximum ratio of this disease is main found in European countries.

What is sleepy sickness?

When an individual suffer from this disorder they become sickness in sleep.

They sleep for hours and hours and might be for a day.

What is Post encephalitis?

Postencephalitic or Parkinsonism disease can be causedto people by a viral illness that helps in triggering degeneration of the nerve cells.

Can you recover from encephalitis?

Yes this disease of Encephalitis lethargica can be recovered easily.

You need to take such medicine prescribed the doctor different medication are used to take this disease and help them becoming normal.

What are the symptoms of encephalitis Lethargica?

There are different types of symptoms of Encephalitis lethargica and they are mentioned as below.

∙ Sore throat

∙ Muscle pains

∙ Headache

∙ Double vision

∙ Delayed responses, both physically and mentally

∙ Lethargy

∙ Catatonia or unresponsiveness

∙ In severe cases, a patient may enter a state resembling coma called akinetic mutism

∙ Tremors

Is there a cure for encephalitis Lethargica?

Different medicines are prescribed for this disease indirectly.

For other neurological disease there are some medicines are recommended by the doctor.

By following the condition the doctor can give for good sleep and main treatment of anxiety and depression.


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