Career Contributions

Dr. Calancie’s career has centered on the use of neurophysiology to understand, measure, protect, and improve motor function. Across studies of human motor control, spinal cord injury, intraoperative neuromonitoring, rehabilitation, cauda equina repair, and ALS, a consistent theme has been the translation of physiologic insight into practical clinical tools.

Human Motor Control and Transcranial Stimulation

A central thread in Dr. Calancie’s work began with early studies of transcranial stimulation of the human motor cortex. During a visiting fellowship in clinical neurophysiology in Uppsala, Sweden, he used non-invasive transcranial cortical stimulation to study single motor unit responses in awake human subjects.

This work helped show how stimulation of the motor cortex could be used to probe descending motor pathways and intracortical inhibitory mechanisms. In particular, weak stimulation could produce a brief pause in the firing of active motor units, suggesting recruitment of inhibitory circuits within the motor cortex.

That early work became an important foundation for later practical applications. The same general principle — stimulating the motor cortex and measuring the motor response — would later support Motor Evoked Potential monitoring in the operating room, as well as laboratory-based TMS methods for studying motor cortex function in spinal cord injury, ALS, and other CNS motor disorders.

In this way, early studies of human motor physiology helped lead to tools with direct clinical relevance.

Intraoperative Neuromonitoring and Surgical Safety

One of Dr. Calancie’s major career contributions has been the development of intraoperative neuromonitoring methods designed to reduce the risk of neurological injury during surgery.

Intraoperative neuromonitoring uses electrophysiologic testing to assess the functional integrity of the brain, spinal cord, nerve roots, cranial nerves, and peripheral nerves during procedures where these structures may be at risk. The goal is to provide the surgical team with early warning of potential injury, while there is still time to intervene.

Dr. Calancie entered this area in the late 1980s, when intraoperative neuromonitoring was still emerging as a field. His laboratory contributed to two areas that became widely used in spine and neurosurgical practice: Motor Evoked Potential monitoring and stimulus-evoked EMG testing for pedicle screw placement.

Motor Evoked Potential Monitoring

Motor Evoked Potential, or MEP, monitoring uses stimulation of the motor cortex to assess the functional integrity of descending motor pathways during surgery.

Dr. Calancie was among the early investigators to apply transcranial electrical stimulation of motor cortex in anesthetized surgical patients. His work helped define practical and physiologic issues that affected MEP monitoring, including the suppressive effects of certain anesthetic agents and the need for reliable multi-pulse stimulation.

Clinical data from his operating room studies supported FDA marketing approval of multi-pulse transcranial stimulation for MEP monitoring. This helped establish MEP testing as a standard neuromonitoring method in many spine, cranial, and vascular surgical procedures.

Pedicle Screw Monitoring

Dr. Calancie’s laboratory also pioneered stimulus-evoked EMG methods for evaluating pedicle screw placement during spinal instrumentation.

Pedicle screws are placed close to nerve roots and, in the thoracic spine, close to the spinal cord. If a screw trajectory breaches the medial wall of the pedicle, neural tissue may be placed at risk. Stimulus-evoked EMG testing can help identify unsafe screw trajectories by assessing the electrical threshold required to activate nearby neural structures.

His laboratory developed and tested methods for both lumbar and thoracic pedicle screw monitoring. A later randomized, blinded clinical trial showed that feedback from pulse-train stimulation reduced the likelihood of medially malpositioned thoracic pedicle screws.

Spinal Cord Injury Plasticity and Recovery

A major portion of Dr. Calancie’s research has focused on how the human nervous system changes after spinal cord injury.

This work examined the natural history of neurophysiologic change after injury, including voluntary movement, reflexes, motor pathway conduction, and involuntary motor activity. A central goal was to distinguish spontaneous changes after injury from changes that might be produced by treatment — a distinction that is essential for evaluating future therapies.

Dr. Calancie’s laboratory helped describe spontaneous involuntary stepping movements after chronic spinal cord injury, providing evidence for a human spinal central pattern generator for locomotion. This finding helped support the idea that spinal circuitry below an injury can retain organized motor programs capable of producing stepping-like activity under certain conditions.

His work also characterized interlimb reflexes after spinal cord injury and examined how new or strengthened connections within the spinal cord may contribute to both adaptive and maladaptive plasticity. These findings have implications for understanding phenomena such as spasticity and autonomic dysreflexia.

Other studies developed electrophysiologic methods for assessing recovery after acute spinal cord injury, including EMG-based measures, tendon reflexes, and lower-limb muscle responses.

Rehabilitation and Neuromodulation After Spinal Cord Injury

Dr. Calancie’s work has also examined interventions intended to improve motor function after spinal cord injury.

In a randomized clinical trial comparing three rehabilitation strategies for people with chronic incomplete spinal cord injury, his laboratory found that most participants improved walking ability by a clinically meaningful amount, regardless of the specific training method used. This suggested that intensive rehabilitation may provide important functional and health-related benefits even many years after injury.

His laboratory also studied multi-pulse transcranial magnetic stimulation as a potential neuromodulatory intervention after spinal cord injury. In case studies of people with incomplete SCI, QuadroPulse rTMS was associated with improved motor function, likely by modifying spinal reflex excitability and reducing interference from spasticity.

Together, these studies supported the broader idea that the injured nervous system may remain responsive to targeted rehabilitation and neuromodulation long after the initial injury.

Continuing Thread

Although these areas span different clinical problems, they share a common foundation: careful measurement of nervous system function.

From early studies of motor unit physiology and transcranial stimulation, to operating-room monitoring, spinal cord injury recovery, rehabilitation, cauda equina repair, and ALS biomarkers, Dr. Calancie’s work has pursued one practical aim:

to use neurophysiology to make motor function more understandable, more measurable, more protected, and, where possible, more recoverable.