Aetiological Aspects of Ammon's Horn Sclerosis Associated with Temporal Lobe Epilepsy*

Thus, the venous ulcer, far from being an ischaemic lesion, is a hyperaemnic lesion. It is sitting on a honeycomb of dilated venules which in fact is rather like a haemangioma. The longer the ulcer has been present the more profuse and sponge-like is the venous sump on which the ulcer sits. Moreover, as time goes on, this hyperaemic area acquires an increased arterial supply; and this venous " sump " under the ulcer can be filled equally well from the arterial or venous side of the circulation, and therefore can be shown equally well by an arteriogram or a venogram (see Fig. 9). Finally, the cause of destruction of the strategic valve in the ankle-perforating veins, and therefore the cause of their incompetence, is deep thrombosis in the majority of cases. Post-thrombotic ankle-perforator incompetence is therefore the main immediate cause of the ulceration, induration, and swelling of the ankle, which is such a prominent feature of the post-thrombotic syndrome of the leg.