Cephalic disorders are commonly congenital conditions that arise due to damage or abnormal growth of the budding of the nervous system. Cephalic word originate from a term means “head”. While congenital refers to the term that disorder refers to the present or condition arises before birth. In this article we gather information related to cephalic congenital disorders.
Cephalic disorders are not the effect of any single disorder but cause by genetic or hereditary conditions or by environmental exposure such as medications taken by mother during pregnancy, exposure to radiation or maternal infection. In some cases the disorder occur during the joining of cranial suture. In most of the cases cephalic disorder occur during the early development of nervous system.
The human nervous system originates from a small plate of cells which is present on the surface of embryo. In early development a neural tube is formed by this plate that closes between the 3rd and 4rth weeks of pregnancy. As a result formation of brain and spinal cord occur. The development of nervous system requires four main process.
- Nerve proliferations in which nerve cells tend to divide and form new cells.
- Next step is the cell migration in which the already formed cells migrate to the position where they have to remain and perform normal functions.
- 3rd step is the cell differentiation in which cells acquire unique characteristics.
- Final step is the cell death in which cells die it is a natural process.
In children the most alarming cause of death is the damage to the developing nervous system. The damage and its effects vary from individual to individual. Some disorders are so severe that they encounter you and makes hurdle throughout the life. Some children eventually die while others remain affected for whole life and even a large no of people remain partially disabled.
Different Kinds of Cephalic Disorders
ANENCEPHALY: It is a common disorder arises when neural tube defect occur when the cephalic region of your neural tube fails to close normally. It usually occur between the 23rd to 26th day of the pregnancy resulting in a severe loss of brain, scalp and mostly of the skull. The infants with anencephaly are deprived of forebrain containing cerebrum, part used mostly for thinking and helps in coordination. The remaining part of the brain is most often don’t covered with bones or skin.
The individuals having anencephaly are mostly deaf, unable to feel pain and unconscious. Individuals mostly born with a rudimentary brainstem, in which cerebrum lack its functioning and person is unable to become conscious throughout life. But some reflexes such as breathing and response to specific sounds may develop. According to one estimate in USA almost 1,000 to 2,000 individuals born with anencephaly every year. It is normally understood that the disorder is most common in females than males.
The exact cause of anencephaly us still unknown it is generally believe that the mothers diet and vitamin intake during pregnancy paly crucial role. But doctors believe that many other factors are also behind this.
Anencephaly cannot be cure by medications because the medications are not proved to be very effective. In most of the cases the individuals die at early age. If the infant don’t born dead then he or she may die just after birth. The only diagnose of anencephaly is the ultrasound before birth.
It is now known that the introduction of folic acid in women during child bearing ae reduces the effects of anencephaly and reduces the neural tube defects. So it is advisable by the doctors that all women bearing child must use 0.4mg of folic acid daily.
COLPOCEPHALY: It is a condition in during which abnormal enlargement of the common occipital horns i.e. the posterior or rear portion of the cavities or chambers commonly known as ventricles of the brain. This enlargement commonly occurs due to the underdevelopment of the white matter commonly located in the posterior cerebrum. It is characterized by small sized head known as microcephaly and leads to mental retardation. The other problems associated with it are muscle spasms, motor abnormalities and seizures.
The cause of the colpocephaly are unknown but doctors believe that it occurs due to an intrauterine disturbance mostly occur during second and sixth months of the pregnancy. It can be diagnose during last stages of the pregnancy but unluckily it is mostly misdiagnosed to be the hydrocephalous a common disorder in which cerebrospinal fluid accumulate in the brain. Nut it can be accurately diagnosed after birth when normal signs and symptoms such as microcephaly, mental retardation and seizures may appear.
No accurate treatment is known for colpocephaly. In most of the cases doctors try to minimize and prevent contractures and advice anticonvulsant medicines.
HOLOPROSENCEPHALY: It is commonly referred as a disorder in which failure of the prosencephalon occurs. During development the forebrain develops but face starts developing in the 5th or 6th weeks of pregnancy. It occurs when brain of the embryo fails to divide in to bilateral cerebral hemisphere which are the right and left halves of the brain. It results in the defects during face development and affects the functioning and structure of brain.
Holoprosencephaly can be classified in to three major classes:
Alobar holoprosencephaly: This is the most serious form in which brain fails to separate and associated with several facial problems.
Semilobar holoprosencephaly: It is the intermediate form in which the hemispheres of the brain may separate.
Lobar holoprosencephaly: It is the least form of holoprosencephaly in which hemisphers are considerably known to divide.
As for others cephalic disorders there is no considerable treatment known for holoprosencephaly. In those individuals who are known to survive have no considerable gain throughout their life.
HYDRANENCEPHALY: It is a condition in which cerebral hemispheres of the brain are absent. This is commonly replaced by the sacs which are filled by the common cerebrospinal fluid. In most of the cases brainstem and cerebellum formed. Mostly the infants ate birth look normal. All the conditions such as swallowing, sucking, head size, crying and movement of the arms and legs seems normal. But after few days the infants feel uneasy and become irritable and increase n muscle tone occur commonly known as hypertonia. After few months hydrocephalous and seizures may develop. The common symptoms are visual impairment, deafness, lack of growth, blindness, and paralysis and intelligence problems arises.
No treatment is known for hydranencephaly and most commonly it is treated with a shunt.
INIENCEPHALY: It is the disorder in which retroflexion of the head combine with severe defects of the spinal cord. The individual is normally short and have abnormal larger head. Diagnosis can done soon after the birth because the head is so much retroflexed that the mouth or face of the infant looks upward. The condition arises because skin of the face don’t separate from the skin of the chest. Neck is usually absent or look like absent. It occurs mostly in females and medication is very poor. The individuals are not able to survive for long time.
LISSENCEPHALY: Literal meaning of the lissencephaly are the smooth brain and commonly characterized by the microcephaly. The common problem is the lack of normal convolutions in the brain. Most often caused by the defective neuronal migration in which the nerve cells migrate from the place of their origin to the place where they will retain for future programming.
Treatment normal depends on the condition that how much severe is the condition and the location of malformations. Special comfort and nursing are the pre-requisite requirements. Require both medications and the shunt.
MEGALENCEPHALY: This is also known as macrencephaly a condition in which abnormally large and malfunctioning of the brain occurs. Normally we can say that the weight of the brain is more that it would be according to the age. It can be easily seen by the enlargement of the head at the time of birth or enlargement may occur soon after birth. It commonly refers to the disturbance in the cell production.
The normal symptoms include delayed development, corticospinal dysfunction, convulsive disorders and common seizures. It affects males more than females. It may lead to a condition known as macrocephaly.
MICROCEPHALY: It is characterized by the smaller skull in which the size of the head is smaller than that it would be according to the age of the individual. Most often it is congenital but sometime may occur during early years of the growth. It may arise due to number of reasons and also associated with chromosomal abnormalities. The individual may born with small or normal head size. With the growing age the smallness of the head become prominent and the entire body is underweight. The motor function develops late and dwarfism occurs.
There is no common treatment which is associated with microcephaly and treatment depends on the symptoms.
PORENCEPHALY: this is the rare problem of the CNS usually involve a cavity or cyst in cerebral hemisphere. These are usually remnants of lesions. But it may occur due to abnormal development. Disorder may develop before or after birth.