Hereditary familial disease characterized by attacks
of choreoathetosis and torsion without loss of consciousness, each episode
lasting from a few minutes to several hours. Alcoholic beverages, coffee,
hunger, fatigue, emotional stress, and tobacco are the precipitating
factors. The presence of an atypical Kayser-Fleischer ring is the principal
Mount Syndrome; Paroxysmal Nonkinesigenic Dyskinesia
(PNKD); Paroxysmal Dystonic Choreoathetosis (PDC).
First described in 1940 by Lester A Mount, an American
physician, and Stan Reback, also an American physician, in a family with many members
over five generations affected with paroxysmal choreoathetosis.
There are no epidemiological studies establishing the incidence or prevalence.
Only few cases have been reported in the literature.
Autosomal dominant. Gene locus is 2q33-2q35.
Unknown; has been suggested it could be an anomaly
of the sodium channel even though it is not a seizure disorder.
Movement disorder can be recognized in the first week of
life. Usually, attacks of choreoathetosis lasting only a few minutes and
occurring several times per day are not associated with loss of
consciousness. The attacks never occur during sleep and at their height are
similar to those occurring in Huntington chorea. Attacks are precipitated by
fatigue, hunger, alcohol, tobacco, or coffee, but not by movement, contrary
to kinesigenic choreoathetosis. Attacks are usually preceded by an aura. The
presence of an atypical Kayser-Fleischer ring is the principal ocular
Usually discovered during the first week of life.
Patients are automatically place on benzodiazepine (diazepam or clonazepam)
therapy to decrease the incidence of crisis and risk.
Administration of benzodiazepines
must be continued up to the operation.
No specific anesthetic experience
reported. No specific medication regimen required; surgery usually performed
under general anesthesia. Bradycardias following small doses of opiates
respond to atropine at normal doses. Monitoring of the level of
neuromuscular blockade is helpful. Maintain normothermia by adequately
warming up the room and infused fluids to prevent shivering. If preoperative
or postoperative sedation is needed, use benzodiazepines. Remember this is
not a seizure disorder.
No specific drug required or to be
avoided. However, benzodiazepines are part of the normal therapy.
Huntington Chorea (HC): An inherited disease characterized by
choreiform movements and progressive dementia. First described in 1872 by
George Huntington, a long island physician. The most famous patient was folk
singer Woody Guthrie.
Hofele K, Benecke R, Auburger G: Gene locus of dystonic Mount Reback-type of
autosomal dominant paroxysmal choreoathetosis. Neurology