Cephalic disorders () are congenital conditions that stem from damage to, or abnormal development of, the budding

nervous system In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes th ...

. Cephalic disorders are not necessarily caused by a single factor, but may be influenced by

hereditary Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic inform ...

or genetic conditions,

nutrition Nutrition is the biochemical and physiological process by which an organism uses food to support its life. It provides organisms with nutrients, which can be metabolized to create energy and chemical structures. Failure to obtain sufficient n ...

al deficiencies, or by environmental exposures during

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ca ...

, such as

medication A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and re ...

taken by the mother, maternal infection, or exposure to

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

. Some cephalic disorders occur when the cranial sutures (the fibrous joints that connect the

bone A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...

s of the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

) join prematurely. Most cephalic disorders are caused by a disturbance that occurs very early in the development of the

fetal A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal develo ...

nervous system. The human nervous system develops from a small, specialized plate of cells on the surface of the

embryo An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...

. Early in development, this plate of cells forms the neural tube, a narrow sheath that closes between the third and fourth weeks of

to form the brain and

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spi ...

of the embryo. Four main processes are responsible for the development of the nervous system: cell proliferation, the process in which

nerve A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the e ...

cells divide to form new generations of cells; cell migration, the process in which nerve cells move from their place of origin to the place where they will remain for life; cell differentiation, the process during which cells acquire individual characteristics; and cell death, a natural process in which cells die. Damage to the developing nervous system is a major cause of chronic, disabling disorders and, sometimes, death in infants, children, and even adults. The degree to which damage to the developing nervous system harms the mind and body varies enormously. Many disabilities are mild enough to allow those affected to eventually function independently in society, others are not. Some infants, children, and adults die, others remain totally disabled, and an even larger population is partially disabled, functioning well below normal capacity throughout life. The National Institute of Neurological Disorders and Stroke (NINDS) is currently "conducting and supporting research on normal and abnormal brain and nervous system development."

Types

More common cephalic disorders

The ICD-10 codes are listed below per disorder. *

Anencephaly Anencephaly is the absence of a major portion of the brain, skull, and scalp that occurs during embryonic development. It is a cephalic disorder that results from a neural tube defect that occurs when the rostral (head) end of the neural tube ...

(Q00.0) *

Colpocephaly Colpocephaly is a cephalic disorder involving the disproportionate enlargement of the occipital horns of the lateral ventricles and is usually diagnosed early after birth due to seizures. It is a nonspecific finding and is associated with multiple ...

(Q04.8) *

Holoprosencephaly Holoprosencephaly (HPE) is a cephalic disorder in which the prosencephalon (the forebrain of the embryo) fails to develop into two hemispheres, typically occurring between the 18th and 28th day of gestation. Normally, the forebrain is formed an ...

(Q04.2) *

Ethmocephaly Ethmocephaly is a type of cephalic disorder caused by holoprosencephaly. Ethmocephaly is the rarest phenotypic variant of a group of defects called the holoprosencephaly (HPE) malformation sequence; other variants include cebocephaly, cyclopia, and ...

(Q04.2) *

Hydranencephaly Hydranencephaly is a condition in which the brain's cerebral hemispheres are absent to a great degree and the remaining cranial cavity is filled with cerebrospinal fluid. "Cephalic" is the scientific term for "head" or "head end of body". Hydrane ...

(Q04.3) *

Iniencephaly Iniencephaly is a rare type of cephalic disorder characterised by three common characteristics: a defect to the occipital bone, spina bifida of the cervical vertebrae and retroflexion (backward bending) of the head on the cervical spine. Stillbi ...

(Q00.2) *

Lissencephaly Lissencephaly (, meaning "smooth brain") is a set of rare brain disorders whereby the whole or parts of the surface of the brain appear smooth. It is caused by defective neuronal migration during the 12th to 24th weeks of gestation resulting in ...

(Q04.3) *

Megalencephaly Megalencephaly (or macrencephaly; abbreviated MEG) is a growth development disorder in which the brain is abnormally large. It is characterized by a brain with an average weight that is 2.5 standard deviations above the mean of the general populati ...

(Q04.5) *

Microcephaly Microcephaly (from New Latin ''microcephalia'', from Ancient Greek μικρός ''mikrós'' "small" and κεφαλή ''kephalé'' "head") is a medical condition involving a smaller-than-normal head. Microcephaly may be present at birth or it ...

(Q02) *

Porencephaly Porencephaly is an extremely rare cephalic disorder involving encephalomalacia. It is a neurological disorder of the central nervous system characterized by cysts or Body cavity, cavities within the cerebral hemisphere.Parker, J. (2004). The offi ...

(Q04.6) *

Schizencephaly Schizencephaly () is a rare birth defect characterized by abnormal clefts lined with grey matter that form the ependyma of the cerebral ventricles to the pia mater. These clefts can occur bilaterally or unilaterally. Common clinical features of ...

(Q04.6)

Less common cephalies

* Acephaly (Q00.0) *

Exencephaly Exencephaly is a type of cephalic disorder wherein the brain is located outside of the skull. This condition is usually found in embryos as an early stage of anencephaly. As an exencephalic pregnancy progresses, the neural tissue gradually degenerat ...

(Q00.0) *

Macrocephaly Macrocephaly is a condition in which circumference of the human head is abnormally large. It may be pathological or harmless, and can be a familial genetic characteristic. People diagnosed with macrocephaly will receive further medical tests to ...

(Q75.3) * Micrencephaly (Q02) * Otocephaly (Q18.2) * Craniosynostosis (Q75.0) **

Brachycephaly Brachycephaly (derived from the Ancient Greek '' βραχύς'', 'short' and '' κεφαλή'', 'head') is the shape of a skull shorter than typical for its species. It is perceived as a desirable trait in some domesticated dog and cat breeds, ...

(Q75.0) **

Oxycephaly Turricephaly is a type of cephalic disorder where the head appears tall with a small length and width. It is due to premature closure of the coronal suture plus any other suture, like the lambdoid, or it may be used to describe the premature fusi ...

(Q75.0) **

Plagiocephaly Plagiocephaly, also known as flat head syndrome, is a condition characterized by an asymmetrical distortion (flattening of one side) of the skull. A mild and widespread form is characterized by a flat spot on the back or one side of the head cause ...

(Q67.3 **

Scaphocephaly Scaphocephaly is a type of cephalic disorder which occurs when there is a premature fusion of the sagittal suture. The sagittal suture joins together the two parietal bones of the skull. Scaphocephaly is the most common of the craniosynostosis con ...

(Q75.0) **

Trigonocephaly Trigonocephaly is a congenital condition of premature fusion of the metopic suture (from the Greek , "forehead"), leading to a triangular forehead. The merging of the two frontal bones leads to transverse growth restriction and parallel growth ex ...

(Q75.0) *

Polycephaly Polycephaly is the condition of having more than one head. The term is derived from the Greek stems ''poly'' (Greek: "πολύ") meaning "many" and ''kephalē'' (Greek: "κεφαλή") meaning "head". A polycephalic organism may be thought o ...

(Q89.4)

Notes

* Note 1: https://web.archive.org/web/20051001003618/http://www.ninds.nih.gov/disorders/cephalic_disorders/cephalic_disorders.htm ''Portions of this article were based on the page: https://web.archive.org/web/20080920160408/http://www.ninds.nih.gov/disorders/cephalic_disorders/detail_cephalic_disorders.htm at the National Institute of Neurological Disorders and Stroke's

public domain resource The public domain (PD) consists of all the creative work to which no exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly waived, or may be inapplicable. Because those rights have expired, ...

.''

References

External links

{{Medical resources , ICD10 = Q00-Q04, Q18, Q67, Q75, Q89 , ICD9 = {{ICD9, 740-{{ICD9, 742 Congenital disorders of nervous system he:מיקרוצפליה nl:Anencefalie

Types

More common cephalic disorders

Less common cephalies

See also

Notes

References

External links