This discovery has led some biologists to argue that there was no selection for or against menopause at the time at which the ancestor of all modern humans lived in Africa, suggesting that menopause is instead a random evolutionary effect of a selection shadow regarding aging in early Homo sapiens. It is also argued that since the population fraction of post-menopausal women in early Homo sapiens was so low, menopause had no evolutionary effect on mate selection or social behaviors related to mate selection. Adaptive hypotheses
"Survival of the fittest" hypothesis
This hypothesis suggests that younger mothers and offspring under their care will fare better in a difficult and predatory environment because a younger mother will be stronger and more agile in providing protection and sustenance for herself and a nursing baby. The various biological factors associated with menopause had the effect of male members of the species investing their effort with the most viable of potential female mates.A problem with this hypothesis is that, if true, we would expect to see menopause exhibited among many species in the animal kingdom, and another problem is that in the case of extended child development, even a female who was relatively young, still agile, and attractive when producing a child would lose future support from her male partner due to him seeking out fertile mates when she reaches menopause, while the child is still not independent.
Spinal extradural haematoma or spinal epidural hematoma (SEH) is bleeding into the epidural space in the spine. These may arise spontaneously (e.g. during childbirth), or as a rare complication of epidural anaesthesia or of surgery (such as laminectomy). Symptoms usually include back pain which radiates to the arms or the legs. They may cause pressure on the spinal cord or cauda equina, which may present as pain, muscle weakness, or dysfunction of the bladder and bowel. Pathophysiology
The anatomy of the epidural space is such that spinal epidural hematoma has a different presentation from intracranial epidural hematoma. In the spine, the epidural space contains loose fatty tissue and a network of large, thin-walled veins, referred to as the epidural venous plexus. The source of bleeding in spinal epidural hematoma is likely to be this venous plexus. Diagnosis
The best way to confirm the diagnosis is MRI. Risk factors include anatomical abnormalities and bleeding disorders. Treatment
Treatment is generally with emergency surgery. The risk following epidural anaesthesia is difficult to quantify; estimates vary from 1 per 10,000 to 1 per 100,000 epidural anaesthetics. == References ==