Convulsions in eclampsia
The convulsion in eclampsia is similar to the seizure in people with epilepsy. Like an epileptic fit, it has four phases:
The quiet stage
The typical feature of the first stage is a period of quiet (it may not take more than 20 seconds) when the person has generalised weak muscles, stiffness and twitch, and staring eyes.
The tonic stage
This may last up to 30 seconds and is characterised by a severe form of generalised muscle spasms, where the muscles of the legs and hands contract very severely and may seem as strong as a dry stick. During the tonic stage, the woman stops breathing and becomes short of oxygen. There is also rolling of the eyes where you can see the upper part of the sclera (the white part of the eye).
The clonic stage
The third stage may take up to 2 minutes and is classically a jerky movement of the whole body as a result of vigorous muscle contraction and relaxation. At this stage, the woman can breathe and she will also salivate and urinate spontaneously.
The coma stage
After the clonic stage is over, in typical cases the woman becomes deeply unconscious for an uncertain period of time. However, a woman can be comatose even from the outset (i.e. without even a single convulsion). The duration of the coma state is dependent on:
- The number of previous convulsions: The higher the number, the longer the duration of coma, which may even end in death. Having a history of more than ten convulsions is one of the poor outcome indicators. Therefore, the earlier the convulsion episodes are controlled, the better the prognosis for the mother and the baby.
- Severity of brain oedema: The space between the skull and the brain is very limited. Thus, even a minimal increase in the mother's brain size due to oedema or haemorrhage will have a serious effect on the brain cells, because the pressure on the brain (the intracranial pressure) rises so high.
- Extent of intracranial haemorrhage (see below in this session): As already described for brain oedema, any bleeding in the intracranial space will increase the intracranial pressure on the brain cells. Additionally, it may aggravate further bleeding and can create a vicious cycle.
- Associated hypoglycaemia (low blood sugar level): Each convulsion requires energy. This is because, during the tonic-clonic stages, almost all the skeletal muscles contract and relax many times. Frequent convulsion means consumption of much energy, which comes from stored sugars in the blood, liver and tissues. The woman with eclampsia cannot replace the sugars used by her muscles quickly enough, so she develops very low blood sugar (severe hypoglycemia), which in turn may manifest in coma. Because her blood sugar is low, the woman with eclampsia invariably will be getting some energy from proteins in her muscles to keep her alive. Breaking down proteins produces ketone bodies that can be used as an energy source and some will appear in her urine. You can test for the presence of ketone bodies with a dipstick.