Abnormality of central motor conduction Prolonged central motor conduction time 2022-11-05T13:36:09Z The determination of central motor conduction time is a sensitive method to detect myelopathies, and abnormalities may be observed in the absence of radiological changes. Increased duration of the central motor conduction time (CMCT). The CMCT estimates the conduction time of corticospinal fibers between motor cortex and spinal (or bulbar) motoneurons. It includes the times for excitation of cortical cells, conduction via the corticobulbar-corticospinal tract and excitation of the motoneuron sufficient to reach its firing threshold. CMCT is calculated by subtracting the peripheral conduction time from the MEP latency recorded after cortical stimulation.