Sporadic Fatal Insomnia (A Comprehensive Guide)

In this brief guide, we will discuss Sporadic Fatal Insomnia, as well as other related concepts like Prion Disease and Creutzfeldt-Jakob Disease.

Sporadic Fatal Insomnia

Sporadic Fatal Insomnia is a type of prion disease and it is neurodegenerative, and as yet there is no treatment for this condition.

Fatal Insomnia is caused by a gene that is usually transmitted from one generation to another but even so, this condition is common and the presence of the prion alone is not enough to cause the disorder.

Sporadic Fatal Insomnia is a variant of a disease known as Familial Fatal Insomnia, which is caused by a Prion Related Protein Gene, and in case of sporadic fatal insomnia this gene is not the problem, which means that Sporadic Fatal Insomnia is not something that is caused by transmission by the parents.

The causes of sporadic fatal insomnia are therefore not known, and it is much rarer than Familial Fatal Insomnia because of the lack of familial transmission.

The signs and symptoms of sporadic fatal insomnia are similar to familial fatal insomnia, however, which are as follow:

  • Progressive insomnia that usually begins during middle age
  • Insomnia may first be mild, but becomes progressively worse
  • Insomnia usually begins suddenly and can rapidly worsen over the next few months. 
  • Vivid dreams
  • Physical and Mental deterioration 
  • Progressive dementia
  • Worsening problems with thought, cognition, memory, language, and behavior. 
  • Unintended weight loss
  • Forgetfulness
  • Inattentiveness
  • Problems concentrating
  • Speech problems
  • Episodes of confusion or hallucinations can eventually occur.
  • Double vision (diplopia)
  • Abnormal
  • Jerky eye movements (nystagmus)
  • Problems with swallowing (dysphagia) 
  • Slurred speech (dysarthria). 
  • Trouble coordinating voluntary movements (ataxia). 
  • Abnormal movements including tremors or twitchy, jerking muscle spasms (myoclonus), 
  • Parkinson’s-like motor symptoms 

Some other symptoms of Sporadic fatal insomnia may include signs like dysfunction of the autonomic nervous system and usually symptoms of this disease tend to vary from one person to another because the specific part of the autonomic nervous system affected can be different. 

Other symptoms that may occur as a result of the dysfunction of Autonomic Nervous System may be fever, rapid heart rate (tachycardia), high blood pressure (hypertension), increased sweating (hyperhidrosis), increased production of tears, constipation, variations in body temperature, and sexual dysfunction including erectile dysfunction. 

In most cases there is also the presence of Anxiety and depression.

However, it is important to remember that these symptoms can easily be the symptoms of other conditions as well, and it would be very difficult to tell exactly what the symptoms of the condition are because there have been so few cases over time, and the brain abnormalities in the condition are very specific to each person.

Sporadic Fatal Insomnia: Case Study

Because Sporadic Fatal Insomnia is such a rare condition, there are only case studies that talk about it in medical literature, and there have been no studies or explorations of this disease otherwise.

When a disease is as rare as Sporadic Fatal Insomnia is, case studies are really the only way to understand it, and whatever symptoms we know about this disease, and what little knowledge we have of its progression, comes from these case studies.

An excerpt from one such Sporadic Fatal Insomnia Case Study is given below, and it is worth noting that this is a case study of the youngest ever patient suffering from Sporadic Fatal Insomnia.

“On February 16, 2009, a 13-year-old boy presented to an emergency department with slow, slurred speech, mood lability, and double vision. The patient had suffered 2 previous concussions: 2 weeks earlier when he was elbowed in the temple, fell, and hit the back of his head and ∼4 months earlier during football practice. 

Computed tomography, MRI, and magnetic resonance angiogram of the head and neck were normal. Due to his neurologic signs and history of concussions, the patient was diagnosed with probable postconcussive syndrome. 

In late March, the patient returned to the hospital for an evaluation by a pediatric neurologist who noted a mild, coarse tremor in his upper extremities. The patient also complained of slowed cognition, memory problems, and difficulties in fine motor function, including writing and occasional balance problems. 

In May 2009, the patient underwent eye surgery to correct esotropia. Approximately 2 weeks later, dysmetria was noted on physical examination as well as prominent sulci with mild to moderate cerebellar atrophy indicated by an MRI.

On June 8, 2009, the patient was hospitalized for worsening coordination and ataxic gait with fever and malaise. Influenza A H1N1 was documented and he was treated with oseltamivir. During hospitalization, a physician noted hyperkinetic movements of the upper and lower extremities. The patient was transferred to a rehabilitation center where several laboratory studies were conducted, including a paraneoplastic panel, the results of which were negative.

On admission, the patient was noted to have shuffling gait and marked memory difficulties. The admitting physician observed the absence of prion disease laboratory tests, but this diagnosis was not pursued. 

The patient continued to gradually decline, and in July 2010 he presented to the emergency department with a broken ankle from climbing out of a second story window. While in the hospital, choreoathetosis, truncal ataxia, and ballistic movements of the arms, legs, and head were observed. Delirium was also noted, but physicians were unsure whether this was due to psychoactive medications or to progression of the underlying condition.

In late September 2011, the patient was rehospitalized for fever and difficulty breathing. Generalized full-body twitches not resulting from seizure activity and possible myoclonic jerking, ankle clonus, and increased body tone were noted during this visit.

Five months later, the patient arrived at the hospital with fever and acute respiratory distress and was admitted to the PICU. He continued to deteriorate and eventually had to be intubated and placed on ventilatory support.

The patient died in February 2012 at the age of 16 years (35 months after illness onset). The cause of death was indicated as respiratory failure secondary to progressive neurodegenerative disorder.”

The full case study may be found here.

Prion Diseases 

Prion diseases is a class of diseases that is caused by malformed proteins that cause the brain to fold in on itself, affecting every single function in the body, and sadly there is not enough information about the causes of prion disease and therefore no treatments are available.

Prion diseases seem to be caused by normal prion protein that may be found on the surface of many cells, becoming abnormal and clumping in the brain, causing brain damage. 

This abnormal accumulation of abnormal protein in the brain can cause memory impairment, personality changes, and difficulties with movement. 

Some common symptoms seen across all major prion diseases include:

  • Rapidly developing dementia
  • Confusion
  • Fatigue
  • Difficulty speaking
  • Difficulty walking and changes in gait
  • Hallucinations
  • Muscle stiffness

Here is a list of all the major Prion diseases known to us so far:

  • Creutzfeldt-Jakob Disease
  • Variant Creutzfeldt-Jakob Disease 
  • Variably protease-sensitive prionopathy (VPSPr).
  • Gerstmann-Sträussler-Scheinker disease (GSS).
  • Kuru. 
  • Familial Fatal insomnia (FI).
  • Sporadic Fatal Insomnia

Creutzfeldt-Jakob Disease

Creutzfeldt-Jakob disease is one of the more common prion diseases, but even this is extremely uncommon, and only affects about a 1000 people in the US every year.

This disease is caused by over 60 mutations in the Prion Related Protein Gene, and it is a neurodegenerative condition, which means that there is no treatment for it and it is usually fatal.

The ICD 10 defines the diagnostic features of this disorder as such:

“Creutzfeldt – Jakob disease should be suspected in all cases of dementia that progresses fairly rapidly over months to 1 or 2 years and that is accompanied or followed by multiple neurological symptoms. 

In some cases, such as the so-called amyotrophic form,the neurological signs may precede the onset of dementia.

There is usually a progressive spastic paralysis of the limbs, accompaniedby extrapyramidal signs with tremor, rigidity, andchoreoathetoid movements. 

Other variants may include ataxia, visual failure, or muscle fibrillation and atrophy of the upper motor neuron type. The triad consisting of

  • rapidly progressing, devastating dementia,
  • pyramidal and extrapyramidal disease with myoclonus, and
  • a characteristic (triphasic) electroencephalogram is thought to be highly suggestive of this disease.”


The condition of usual insomnia is very different from that of sporadic fatal insomnia, and it includes none of the same markers as this condition.

Insomnia is defined as trouble falling asleep, trouble staying asleep, or trouble maintaining sleep, any of which can be classified and treated as insomnia.

The diagnostic features of Insomnia in the ICD 10 are as follow:

“Insomnia is a condition of unsatisfactory quantity and/or quality of sleep, which persists for a considerable period of time. The actual degree of deviation from what is generally considered as a normal amount of sleep should not be the primary consideration in the diagnosis of insomnia, because some individuals (the so-called short sleepers) obtain a minimal amount of sleep and yet do not consider themselves as insomniacs. 

Conversely, there are people who suffer immensely from the poor quality of their sleep, while sleep quantity is judged subjectively and/or objectively as within normal limits.”

“Among insomniacs, difficulty falling asleep is the most prevalent complaint, followed by difficulty staying asleep and early final awakening. Usually, however, patients report a combination of these complaints. 

Typically, insomnia develops at a time of increased lifestressand tends to be more prevalent among women, older individuals and psychologically disturbed and socioeconomically disadvantaged people. 

When insomnia is repeatedly experienced, it can lead to an increased fear of sleeplessness and a preoccupation with its consequences.This creates a vicious circle which tends to perpetuate the individual’s problem.”

If you’re facing this, it may be a good idea to seek the help of a therapist or other mental health professional. You can find a therapist at BetterHelp who can help you learn how to cope and address it.


In this brief guide, we discussed Sporadic Fatal Insomnia, as well as other related concepts like Prion Disease and Creutzfeldt-Jakob Disease.

Sporadic fatal insomnia is a very rare condition that is usually inherited, and it is not nearly the same as the usual kind of insomnia that people tend to suffer from in society.

If you have any other questions or comments about Sporadic Fatal Insomnia please feel free to reach out to us at any time.

Frequently Asked Questions (FAQs): Sporadic Fatal Insomnia

How common is sporadic fatal insomnia?

Sporadic fatal insomnia is very uncommon, and It has only been described in medical literature in about two dozen people. Sporadic fatal insomnia comes under prion diseases that collectively affect about 1 in 1,000,000 million people in the general population per year.

Do I have fatal insomnia?

You likely don’t have fatal insomnia, as it is a very rare condition, but you can try to compare your symptoms to that of fatal insomnia, which tend to be difficulty falling or staying asleep experiencing vivid dreams and muscle spasms or stiffness and brain damage.

How long can you live with fatal insomnia?

Most people cannot live very long with fatal insomnia, and in most cases death usually occurs due to fatal insomnia within 12 to 18 months, with a range of a few months to several years.

How does fatal familial insomnia kill you?

Fatal familial insomnia usually keeps getting worse with time and leads to dementia first, and then it can lead to exhaustion, coma, and eventually death.






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