temporal summation
Neurophysiological phenomenon where rapid successive stimuli produce enhanced responses, testing synaptic function.
Full Definition
Temporal summation refers to the enhanced neurophysiological response that occurs when stimuli are delivered in rapid succession, allowing individual responses to build upon each other before complete decay occurs. This phenomenon is particularly important in repetitive nerve stimulation testing, where it can mask underlying neuromuscular junction defects by temporarily improving neurotransmitter release. In patients with myasthenia gravis or Lambert-Eaton syndrome, rapid stimulation may initially improve muscle responses through temporal summation before fatigue becomes apparent. Understanding temporal summation is crucial for proper timing of stimulation protocols and interpretation of repetitive stimulation test results.
Usage
Usage note: Distinguished from post-tetanic potentiation by timing and mechanism; important for test protocol design.
In Context
- "Temporal summation initially masked the neuromuscular junction defect during rapid stimulation." — Repetitive stimulation study report
- "The improved response reflected temporal summation rather than recovery from the underlying disorder." — Neuromuscular junction assessment