Myoclonus is a condition related to epilepsy of involuntary twitching or jerking of the
The purpose of this study is to determine if stimulation of the brain with magnetic pulses
can decrease myoclonus. Researchers believe that this may be possible because in studies on
normal volunteers, magnetic stimulation made areas of the brain difficult to activate for
several minutes. In addition, early studies on patients with myoclonus have shown magnetic
stimulation to be effective at decreasing involuntary movements.
Transcranial Magnetic Stimulation (TMS) is a non-invasive technique that can be used to
stimulate brain activity and gather information about brain function. It is very useful
when studying the areas of the brain and spinal cord related to motor activity (motor cortex
and corticospinal tract). Repetitive transcranial magnetic stimulation (rTMS) involves the
placement of coil of wire (electromagnet) on the patient's scalp and rapidly turning on and
off the electrical current. The changing magnetic field produces weak electrical currents in
the brain near the coil. This permits non-invasive, relatively localized stimulation of the
surface of the brain (cerebral cortex). The effect of magnetic stimulation varies,
depending upon the location, intensity and frequency of the magnetic pulses.
Researchers plan to use rTMS for 10 days on patients participating in the study. The 10 day
period will be broken into 5 days of active repetitive magnetic stimulation and 5 days of
placebo "ineffective" stimulation. At the end of the 10 day period, if the results show
that rTMS was beneficial, patients may undergo an additional 5 days of active rTMS.
Repetitive transcranial magnetic stimulation (rTMS) at frequencies in the single Hz range
causes a decrease in the excitability of the primary motor cortex and there is preliminary
evidence that it can suppress abnormal excess cortical activity. We plan to test 1 Hz rTMS
as treatment for cortical myoclonus.
Age 5 to 90 with severe cortical myoclonus.
No intracranial metal hardware (excluding dental fillings), pacemakers, indwelling
medication pumps, cochlear implants, intracardiac lines, significant intracranial masses
or increased intracranial pressure.
Subject must not be pregnant.