Clinical Study attributes
Background: - People with motor neuron disorders have changes in the parts of the brain that control movement. Some tests that are currently used to study these changes are magnetic resonance imaging (MRI) and transcranial magnetic stimulation (TMS). We don t know if MRI scans and TMS give the same results if done at different times in the same person. Researchers want to see if these tests produce different results if given to healthy adults on two separate occasions. Objectives: - To test the reliability of different tests of the brain used to study motor neuron disorders. Eligibility: * \<TAB\>Healthy individuals at least 35 years of age who have no history of neurological disorders and take no medications. * \<TAB\>Pregnant women may not participate. Design: * Participants will be screened with a medical history and physical exam. * Participants will have two testing visits 1 to 6 months apart. * The first visit will have three parts. The first part is a neurological exam to test strength, sensation, reflexes, and coordination of movement. The second part will be TMS tests. The third part will involve an MRI scan to study the parts of the brain that control movement. * At the second visit, participants will have MRI scanning only.