Information on the following diseases can be found in the Related Disorders section of this report:

• Tourette Syndrome
• Kok Disease

The symptoms of "Jumping Frenchmen" usually begin after puberty or during the teenage years. Individuals affected by this disorder display an extreme startle reaction consisting of jumping, raising the arms, yelling, hitting, obeying sudden commands, or involuntarily repeating sentences. The intensity of the response may be affected by the frequency of being startled, fatigue and/or stress. The affected person must be startled by an unexpected event in order to elicit the reaction. Consequently other people tend to tease and startle those affected by "Jumping Frenchmen" in order to cause the unusual reaction.

The cause of "Jumping Frenchmen" is unknown. It may be a hereditary neurological condition or it may have a strong cultural influence within relatively isolated groups of people. The startle reaction is a normal human response to sudden and unexpected noise or movement. Suddenly startling an individual who has "Jumping Frenchmen" causes an extreme startle reaction which is even more intense if the person is tired or anxious. In some cases, this reaction may include violence. Some medical researchers believe the phenomenon may be triggered by a specific situation as a conditioned response. Others believe it may be a hereditary neurological condition.

Originally, "Jumping Frenchmen" was identified in the Moosehead Lake region of Maine among French Canadian lumberjacks. It seems to have been common in the lumber camps of the region during the nineteenth and early twentieth centuries. However, "Jumping Frenchmen" is not limited to French Canadian lumberjacks. Similar behavior has been observed in specific populations in Malaysia, Siberia, India, Somalia, Yemen and the Philippines. The disorder tends to occur more often in males than in females.

Tourette Syndrome is a hereditary neurological movement disorder which begins between the ages of two and sixteen. The disorder is characterized by involuntary muscular movements known as tics and uncontrollable vocal sounds; sometimes inappropriate words may occur. Tourette Syndrome is not a degenerative disorder and those affected can expect to live a normal life span. Gilles de la Tourette Syndrome has some similarities to "Jumping Frenchmen". Imitative repetition of words (echolalia) or actions (echopraxia) is common to both conditions. However, aside from these symptoms there is no relationship between these two disorders. (For more information on this disorder, choose "Tourette Syndrome" as your search term in the Rare Disease Database.)

Hyperekplexia is characterized by an excessive startle response, falling without loss of consciousness, a history of resistance to stretching (hypertonia) in infancy, exaggeration of reflexes (hyperreflexia), and an unstable gait. Individuals with this disorder do not have the imitative repetition of words or actions, or the forced obedience response found in "Jumping Frenchmen". Hyperekplexia is thought to be a hereditary disorder.

"Startle Epilepsy" can occur after Hemiplegia (a syndrome characterized by muscle spasms of both limbs on one side of the body) or Infantile Encephalopathy (a degenerative brain disorder of infants). It is expressed as a brief muscular contraction predominating on one-half of the body in response to sudden noise or movement. This reaction is not as complex and directed as "Jumping Frenchmen". These patients often fall when startled and also have other seizure manifestations. (For more information on this disorder, choose "Epilepsy" as your search term in the Rare Disease Database.

Kok Disease is a rare hereditary neurological disorder. Individuals with this disorder have an excessive startle reaction to sudden unexpected noise, movement, or touch. Arching of the head, jerking movements (myoclonic jerks), or falling swiftly to the ground (like a log) without loss of consciousness tend to occur when the individual is startled. Other symptoms may include extreme muscle tension sometimes causing stiffness (hypertonia), exaggeration of reflexes (hyperreflexia), and an unstable gait.

Eliminating the practice of intentionally startling and/or teasing an individual so as to cause a jumping response can help to reduce or end episodes. The startle response can be avoided if the patient expects a sudden noise or movement. Symptoms tend to get milder with age, but more intense with stress or anxiety.

The National Institute of Neurological Disorders and Stroke of the National Institutes of Health is evaluating its study of people with excessive startle responses. Various tests, including electrophysiological studies, were conducted. No further patients are being accepted for this study.

TEXTBOOKS
Adams, RD, et al., eds. Principles of Neurology. 6th ed. New York, NY: McGraw-Hill, Companies; 1997:106.

Menkes JH., au., Pine JW, et al., eds. Textbook of Child Neurology, 5th ed. Baltimore, MD: Williams & Wilkins; 1995:167.

JOURNAL ARTICLES
Bartholomew RE., The idiom of latah: reply to Dr. Simons. J Nerv Ment Dis. 1995;183:184-86.

Bartholomew RE., Disease, disorder, or deception? Latah as habit in a Malay extended family. J Nerv Ment Dis. 1994;182:331-38; discussion 339-41.

Howard R, et al., From the jumping Frenchmen of Maine to post-traumatic stress syndrome: the startle response in neuropsychiatry. Psychol Med. 1992;22:695-707.

Jenner JA., A successfully treated Dutch case of latah. J Nerv Ment Dis. 1991;179:636-37.

Jenner JA., Latah as coping: a case study offering a new paradox to solve the old one. Int J Soc Psychiatry. 1990;36:194-99.

Sainte-Hilaire M, et al., Jumping Frenchmen of Maine. Neurology. 1986;36:1269-1271.