What are the other Names for this Condition? (Also known as/Synonyms)

• Facial Onset Sensorimotor Neuronopathy Syndrome
• Facial Onset Sensory and Motor Neuronopathy Syndrome
• FOSMN Syndrome

What is Facial Onset Sensory and Motor Neuronopathy? (Definition/Background Information)

• Facial Onset Sensory and Motor Neuronopathy (FOSMN) is a rare and slowly progressive motor neuron disorder
• Affected people initially experience facial tingling and numbness which eventually spread to the scalp, neck, upper trunk and upper limbs. These sensory abnormalities are later followed by the onset of motor symptoms such as cramps, muscle twitches, difficulty swallowing, dysarthria, muscle weakness and atrophy
• The hallmark of FOSMN is the reduced or absence of the corneal reflex (the reflex to blink when something touches the eye)
• The underlying cause is currently unknown. Most cases appear to occur sporadically in people with no family history of the condition
• Although there is no consensus regarding the best treatment options for FOSMN, some affected people have temporary improvement in response to intravenous immunoglobulin or plasmapheresis

(Source: Facial Onset Sensory and Motor Neuronopathy; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

Who gets Facial Onset Sensory and Motor Neuronopathy? (Age and Sex Distribution)

• Facial Onset Sensory and Motor Neuronopathy is a rare congenital disorder. The presentation of symptoms may occur between the ages of 38-77 years 
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Facial Onset Sensory and Motor Neuronopathy? (Predisposing Factors)

• Currently, no risk factors have been clearly identified for Facial Onset Sensory and Motor Neuronopathy

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Facial Onset Sensory and Motor Neuronopathy? (Etiology)

The underlying cause of Facial Onset Sensory and Motor Neuronopathy is currently unknown.

• Because the clinical features and severity of the condition can vary significantly from person to person, it is thought that there may be a multifactorial cause
• Some studies suggest that the condition may occur due to an abnormal immune response or neurodegeneration (degeneration of certain motor and sensory neurons, specifically)
• Studies have also shown that SOD1 and OPMD genes may play a role in FOSMN; however, the specific association is unclear
• Although there are currently no familial cases of FOSMN reported in the medical literature, some scientists suspect that newer genetic testing technologies may uncover additional genetic factors

(Source: Facial Onset Sensory and Motor Neuronopathy; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

What are the Signs and Symptoms of Facial Onset Sensory and Motor Neuronopathy?

The signs and symptoms of Facial Onset Sensory and Motor Neuronopathy may vary among affected individuals in type and severity.

• Facial tingling and numbness which eventually spread to the scalp, neck, upper trunk and upper limbs 
• Dysarthria
• Fasciculations
• Muscle cramps
• Muscle weakness
• Paresthesia
• Skeletal muscle atrophy
• Reduced corneal reflex (the reflex to blink when something touches the eye)

(Source: Facial Onset Sensory and Motor Neuronopathy; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

How is Facial Onset Sensory and Motor Neuronopathy Diagnosed?

Due to the small number of reported cases, there are no agreed upon diagnostic criteria for Facial Onset Sensory and Motor Neuronopathy. A diagnosis is often suspected based on the presence of characteristic signs and symptoms. Additional tests may then be ordered to support the diagnosis and rule out other conditions that are associated with similar features.

These include:

• Electromyography and nerve conduction studies
• Laboratory tests
• Lumbar puncture (spinal tap)
• MRI of the brain and spinal cord

(Source: Facial Onset Sensory and Motor Neuronopathy; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Facial Onset Sensory and Motor Neuronopathy?

The complications of Facial Onset Sensory and Motor Neuronopathy may include:

• Extreme muscle weakness leading to difficulties in movement
• Reduced quality of life

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Facial Onset Sensory and Motor Neuronopathy Treated?

• Due to the rarity of the condition, the best approach for effective treatment for Facial Onset Sensory and Motor Neuronopathy is currently unclear
• Several treatments have been mentioned in case reports including:
  • Intravenous immunoglobulin (IVIG)
  • Plasmapheresis (PE)
  • Corticosteroids
  • Azathioprine
  • Mycophenolate mofetil
  • Rituximab
• Although some patients showed temporary improvements with IVIG and PE, the majority of cases did not respond to any of these treatments

(Source: Facial Onset Sensory and Motor Neuronopathy; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

How can Facial Onset Sensory and Motor Neuronopathy be Prevented?

• At the present time, there are no methods or guidelines available for the prevention of Facial Onset Sensory and Motor Neuronopathy 
• Active research is currently being performed to explore the possibilities for treatment and prevention of disorders such as Facial Onset Sensory and Motor Neuronopathy
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of Facial Onset Sensory and Motor Neuronopathy? (Outcomes/Resolutions)

• The prognosis of Facial Onset Sensory and Motor Neuronopathy is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Facial Onset Sensory and Motor Neuronopathy:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/