Startle/ Stimuli Sensitive Myoclonus- What do you know about it?

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Permalink Reply by ramona on November 2, 2009 at 8:47pm

Monica,
Many movement disorders are quite sensitive to stimuli such as startling, lights, noises, etc. In my own case, high pitched noises, bright and flashing lights, and being startled can all trigger intense dystonic spasms, usually temporary in nature.

Ramona

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Permalink Reply by Monica Coogan on November 2, 2009 at 9:03pm

well, now this is the only symptom he displays now that he is off of offending medications. yes dystonia can be aggravated by anxiety, and the anxiety would make you stimuli sensitive. it doesn't sound like the same thing. sigh .... i wish i had psychic powers.

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Permalink Reply by Jenn on November 2, 2009 at 10:48pm

Myoclonus is a separate condition from dystonia. It sounds like you are aware of that but not everyone is. There are some people who have symptoms of both myoclonus and dystonia but it is rare, and from what I read the myoclonus in that is a little different than 'true' myoclonus.

Is your question: Is myoclonus caused/exasperated by external stimuli? Yes.

Stimulus-sensitive myoclonus is triggered by a variety of external events, including noise, movement, and light. Surprise may increase the sensitivity of the individual.
http://www.ninds.nih.gov/disorders/myoclonus/detail_myoclonus.htm

Clonazepam is one medicine used to treat it.

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Permalink Reply by beka on November 21, 2009 at 2:53pm

I will look into this for you tonight at work as there might be some clues to the startle response, dystonia and other movement disorders.

beka

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Permalink Reply by beka on November 22, 2009 at 4:45pm

The NIH just finished a study on Startle reflexes and dystonia.

This study will use three neurophysiological tests (see below) to determine what areas of the brain are responsible for paroxysmal hyperkinetic movement disorders. Patients with these disorders have sudden, brief attacks of movement, similar to epileptic seizures, but without loss of consciousness.

Normal volunteers and patients with two subtypes of paroxysmal hyperkinetic movement disorder, paroxysmal dyskinesia and psychogenic variant, that can be induced by a specific trigger, such as a sudden movement or prolonged exercise, will be included in this study. Candidates must be 12 years of age or older. Women of childbearing potential will be screened with a pregnancy test.

Participants will undergo one or more of the procedures detailed below. Patients' test results will be compared with those of normal volunteers. Before each test, participants will provide a medical history and undergo a brief physical examination. During each procedure, the subject will have surface electromyography (EMG) to measure the electrical activity of muscles. For EMG, electrodes (metal discs) filled with a conductive gel are taped to the skin over the muscle to be evaluated.

Functional Magnetic Resonance Imaging (fMRI)

MRI uses a strong magnetic field, radio waves, and computer technology to provide detailed images of the brain. For this test, the subject lies in a narrow cylinder (the scanner), while pictures of the brain are taken. Earplugs are worn to muffle loud noises caused by electrical switching of radio frequency circuits used in the scanning process. For functional MRI (fMRI), the subject is asked to mimic a movement that occurs during an attack, such as stiffening the hand to make a fist or flexing and rotating the arm inward, to detect changes in the brain regions involved in the movement. During the procedure, involuntary movements and voluntary movements will be monitored by surface EMG and by video camera. The test will last about 1-1/2 hours.

Electroencephalography (EEG)

EEG measures the electrical activity of the brain (brain waves) with electrodes placed on the scalp. During the procedure, muscle activity will be recorded with EMG. The subject will first relax and then will be asked to mimic a movement attack. The test will last from 1-1/2 to 2 hours.

Startle Reflex

The subject will put on a headphone and hear loud noises in a random fashion. During the test, muscle activity will be recorded with EMG and with a video camera....

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Here's a good link on startle reflexes.
www.mdc.lhsc.on.ca/mdc/pdf/misc.pdf
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Here is something from the NIH : www.ncbi.nlm.nih.gov/pmc/articles/PMC2702449/
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Link :www.ionchannels.org/showabstract.php?pmid=16713923

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Hope this info gets others thinking..
beka

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