These cases can be discovered later on electrocardiograms, using blood enzyme tests, or at autopsy after a person has died. Such silent myocardial infarctions represent between 22 and 64% of all infarctions, and are more common in the elderly, in those with diabetes mellitus and after heart transplantation. In people with diabetes, differences in pain threshold, autonomic neuropathy, and psychological factors have been cited as possible explanations for the lack of symptoms. In heart transplantation, the donor heart is not fully innervated by the nervous system of the recipient. Risk factors
The most prominent risk factors for myocardial infarction are older age, actively smoking, high blood pressure, diabetes mellitus, and total cholesterol and high-density lipoprotein levels. Many risk factors of myocardial infarction are shared with coronary artery disease, the primary cause of myocardial infarction, with other risk factors including male sex, low levels of physical activity, a past family history, obesity, and alcohol use. Risk factors for myocardial disease are often included in risk factor stratification scores, such as the Framingham Risk Score. At any given age, men are more at risk than women for the development of cardiovascular disease. High levels of blood cholesterol is a known risk factor, particularly high low-density lipoprotein, low high-density lipoprotein, and high triglycerides.Many risk factors for myocardial infarction are potentially modifiable, with the most important being tobacco smoking (including secondhand smoke). Smoking appears to be the cause of about 36% and obesity the cause of 20% of coronary artery disease.
It is a common symptom of other neurological disorders in newborns, can be caused as a result of shunt treatment of hydrocephalus, developmental disorders in premature infants, due to intrauterine disturbances during pregnancy, genetic disorders, underdevelopment or lack of white matter in the cerebrum, and exposure of the mother and the developing fetus to medications, infections, radiation, or toxic substances. Also, it is usually more common in premature infants than in full-term infants, especially in babies born with hypoxia or lung immaturity. Some of the central nervous system disorders which are associated with colpocephaly are as follows:
polymicrogyria
Periventricular leukomalacia (PVL)
intraventricular hemorrhage
Hydrocephalus
schizencephaly
microgyria
microcephaly
Pierre-Robin syndrome
NeurofibromatosisOften colpocephaly occurs as a result of hydrocephalus. Hydrocephalus  is the accumulation of cerebrospinal fluid (CSF) in the ventricles or in the subarachnoid space over the brain. The increased pressure due to this condition dilates occipital horns causing colpocephaly. The most generally accepted theory is that of neuronal migration disorders occurring during the second to fifth months of fetal life. Neuronal migration disorders are caused by abnormal migration, proliferation, and organization of neurons during early brain development. During the seventh week of gestation, neurons start proliferating in the germinal matrix which is located in the subependymal layer of the walls of the lateral ventricles. During the eighth week of gestation, the neurons then start migrating from the germinal zone to cortex along specialized radial glial fibers. Next, neurons organize themselves into layers and form synaptic contacts with other neurons present in the cortex.