2-53b - Venous Pulsations

On the disc, look for spontaneous venous pulsations. Spontaneous venous pulsations can be seen in the large trunks of veins at the level of the disc margin. They are normally present and seen in 37-90% of normals -- depending on the experience of the examiner and the shape of the disc. The spontaneous venous pulsation is thought to occur because there is a common wall at the level of the lamina cribrosa, where arterial pulse is easily transmitted to the thinner walled venous vessel. Spontaneous venous pulsations occur usually when the pressure in the cranium is normal. Individuals tend to lose these pulsations if the pressure is elevated. However, caution must be used in interpreting this statement since in normal individuals, spontaneous venous pulsations may not be seen and occasionally, in pathologically increased intracranial pressure, SVP may still be present. Pair with 2-53a.