Effects of essential hypertension on short latency human somatosensory-evoked potentials

Reduced perception of somatosensory stimulation in patients with essential hypertension may be due to deficits in the ascending somatosensory pathway. Function in the ascending somatosensory pathway was assessed bymeasuring N9, N13, and N20 somatosensory-evoked potentials in 14 unmedicated essential hypertensives and 22 normotensives. N9 amplitudes were smaller and N13 amplitudes marginally smaller in hypertensives than normotensives. N9 amplitudes were inversely associated with blood pressure. N20 amplitudes and N9, N13, and N20 latencies did not differ between groups. In addition, plexus-to-cord, cord-to-cortex, and plexus-to-cortex conduction times were not different between groups. These data suggest that hypertension affects the peripheral nervous system by reducing the number of active sensory nerve fibers without affecting myelination. However, hypertension does not seem to affect the afferent somatosensory pathway within the brain.