(affiliated with Movement Disorders)
Clinical Motor Physiology Training Program
Clinical motor physiology is that area of medicine in which neurological disorders of movement are evaluated, monitored and treated using a combination of clinical assessment and electrophysiological testing. The field assesses derangements of normal physiology of the nervous system and uses electrophysiological methods to evaluate the abnormal physiological state.
During their training in the Clinical Motor Physiology Laboratory (CMPL), fellows acquire detailed knowledge of the normal physiology and relevant anatomy of the nervous system; the normal and abnormal electrophysiology of the central and peripheral nervous system; and the electrophysiological procedures specifically related to movement disorders and neuromuscular diseases.
Fellows learn how to approach patients clinically with an appreciation and understanding of the most appropriate neurophysiologic tests or procedures that would help with their care.
The CMPL trains fellows to become proficient in microelectrode recordings to map subcortical nuclei and white matter tracts during deep brain stimulator (DBS) implantation in patients with Parkinson’s disease, dystonia, and related disorders. Fellows also learn neurophysiologic monitoring with EMG and evoked potentials to ascertain further precise DBS placement and detect side effects in the operating room.
EMG-guided botulinum toxin injections, particularly for limb disorders including dystonia, tremor, and spasticity are taught with special emphasis on focal task-specific dystonia affecting musicians. Fellows gain detailed knowldge of all muscle systems of the body, their involvement in clinical disorders, and the benefits and drawbacks of botulinum toxin treatment.
The CMPL performs several other quantitative motor physiology tests for movement disorders and neuromuscular disease among which are tremor analysis, polymyography, reaction and movement times, spiral analysis, backaveraging EEG to EMG, and transcranial magnetic stimulation. Experimental techniques are investigated such as computerized quantitative assessments of musical performance, facial expression analysis in patients with Parkinson’s disease, and fMRI changes associated with spiral kinematics.
Specific objectives include, but are not limited to, knowledge of the following:
- The neuroscience of motor control, including supraspinal, brainstem, spinal and peripheral mechanisms.
- Special instrumentation requirements for assessing normal and abnormal motor control.
- The pathophysiology, including central and peripheral mechanisms, of tremor, bradykinesia, rigidity, ataxia, myoclonus and dystonia.
- Developing electrophysiologic testing strategies to address the unique problems of individual patients.
- Specific methods of recording tremor and other hyperkinetic disorders, applications of spiral analysis to evaluate the kinematics and dynamics of upper limb motor control, the use of EMG and EEG to assess myoclonus, measuring reaction and movement time, and becoming proficient in EMG-guided botulinum toxin injections for dystonia, tremors, and spasticity.
- Extracellular microelectrode recordings for mapping, and intra-operative physiologic methods for monitoring, DBS implant surgery.
Involvement in clinical research is encouraged. Current CMPL research projects include:
- Analysis of motor control before and after DBS implantation.
- Evaluation of the efficacy of botulinum toxin treatment for focal dystonia in musicians using computerized measures of musical performance.
- Utility of spiral analysis in detecting early Parkinson’s disease.
- Physiological and clinical investigations of essential tremor, including the co-existence of ataxia.
- Neurophysiologic biomarkers of upper motor neuron dysfunction.
- Digital analysis of facial affect in patients with Parkinson’s disease.
- Tremor and spiral analysis studies in patients with Parkinson’s disease and action tremors.
- Correlation of fMRI with spiral kinematics in normal motor function and essential tremor.
Summary of the tests and procedures offered in the CMPL:
Motor function tests
- Tremor analysis with accelerometry and rectified, integrated EMG. Time and frequency analyses. Coherence between selected signals, e.g. EMG/movement or limb/limb. All types of tremor are analyzed to assist in the diagnosis of ET, Parkinson’s disease, and dystonic tremors, help in discerning combinations of tremor types, investigate psychogenic tremors and determine the presence of orthostatic tremor.
- Polymyography using multiple topographic distribution of EMG to evaluate forms of spinal myoclonus, dystonia and complex movement disorders.
- Movement speed analysis. Computer-controlled measurement of repeated movements that are clinical useful for patients with Parkinson disease.
- Spiral analysis: the quantification of upper limb kinematics and dynamics during spiral drawing on a pressure sensitive digitizing tablet. This test quantifies several clinically relevant indices including degree of motor disability, tremors in three axes, speed, micrographia and ataxia.
- Backaveraging EEG to EMG to determine whether EEG transients are time-locked to quick involuntary muscle activity, helpful in the diagnosis of cortical myoclonus. Longer duration trials are used to measure Bereitschaftspotentials.
- Transcranial motor evoked responses using magnetic stimulation to measure central conduction times in progressive neurologic disorders and spinal cord dysfunction.
Brainstem and spinal reflex analyses
- Blink reflex recovery in Parkinson’s disease, dystonia and related conditions.
- Reciprocal and recurrent inhibition and the spinal involvement in motor neuron disease and conduction block neuropathy.
- Silent period analysis investigating peripheral vs. central stimulation issues.
- Warned/unwarned reaction time analysis and investigations into various subcortical pre-movement circuitry.
- Complex paradigms studying hemi-neglect and lower body parkinsonism.
Botulinum toxin injections
- These are performed with EMG guidance for approved uses such as in dystonia, spasticity, cerebral palsy, and off-label applications in special conditions such as tremor, myoclonus, and prior to orthopedic procedures.
- Focal task-specific dystonia in musicians specifically is studied with quantification of musical performance before and after botulinum toxin injections.
- Investigations into other uses of botulinum toxin, including sialorrhea, pain relief and altering central motor control mechanisms.
DBS mapping and monitoring
- Single unit microelectrode recordings of neuronal firing patterns and fiber tract signals during mapping of subcortical nuclei targeted for DBS placement. Emphasis is placed on understanding the technical requirements for reliable mapping. Developing the best strategies to achieve the electrophysiological objectives in a particular patient, and real-time problem solving.Fellows become knowledgeable about the indications for intraoperative mapping, the effective use of anesthetic agents, and differentiating between transient, insignificant electrophysiologic changes and those of clinical importance.
- Intra-operative monitoring including EMG to measure tremors, other movements, and side effects of DBS; visual and other evoked responses to ensure proper DBS placement.