Cephalic disorders () are

congenital A birth defect is an abnormal condition that is present at childbirth, birth, regardless of its cause. Birth defects may result in disability, disabilities that may be physical disability, physical, intellectual disability, intellectual, or dev ...

conditions that stem from damage to, or abnormal development of, the budding

nervous system In biology, the nervous system is the complex system, highly complex part of an animal that coordinates its behavior, actions and sense, sensory information by transmitting action potential, signals to and from different parts of its body. 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 biochemistry, biochemical and physiology, physiological process by which an organism uses food and water to support its life. The intake of these substances provides organisms with nutrients (divided into Macronutrient, macro- ...

al deficiencies, or by environmental exposures during

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

, such as

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

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 a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infr ...

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

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

s of the

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

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

fetal A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic stage, the fetal stage of development takes place. Prenatal development is a ...

nervous system. The human nervous system develops from a small, specialized plate of

cells Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a d ...

on the surface of the

embryo An embryo ( ) is the initial stage of development for 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 sp ...

. 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 that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

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). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the Electrochemistry, electrochemical nerv ...

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

apoptosis Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...

, 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 Disability is the experience of any condition that makes it more difficult for a person to do certain activities or have equitable access within a given society. Disabilities may be cognitive, developmental, intellectual, mental, physica ...

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 The National Institute of Neurological Disorders and Stroke (NINDS) is a part of the U.S. National Institutes of Health (NIH). It conducts and funds research on brain and nervous system disorders and has a budget of just over US$2.03 billion. The ...

(NINDS) is currently "conducting and supporting research on normal and abnormal brain and nervous system development."

Types

More common cephalic disorders

The

ICD-10 ICD-10 is the 10th revision of the International Classification of Diseases (ICD), a medical classification list by the World Health Organization (WHO). It contains codes for diseases, signs and symptoms, abnormal findings, complaints, social cir ...

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 (Q04.8) *

Holoprosencephaly Holoprosencephaly (HPE) is a cephalic disorder in which the prosencephalon (the forebrain of the embryo) fails to Prenatal development, develop into two Cerebral hemisphere, hemispheres, typically occurring between the 18th and 28th day of gestati ...

(Q04.2) * Ethmocephaly (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. Hydranencephaly is a type of cephalic disorder. These disorders are cong ...

(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 are smooth. It is caused by defective neuronal migration during the 12th to 24th weeks of gestation, resulting in a ...

(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 Neo-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 m ...

(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 of the Human brain, brain, 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. C ...

(Q04.6)

Less common cephalies

* Acephaly (Q00.0) * Exencephaly (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 Heredity, familial genetic characteristic. People diagnosed with macrocephaly will receive further medical ...

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

Craniosynostosis Craniosynostosis is a condition in which one or more of the fibrous sutures in a young infant's skull prematurely fuses by turning into bone (ossification), thereby changing the growth pattern of the skull. Because the skull cannot expand perpe ...

(Q75.0) **

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

(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 (anatomy), suture, like the Lambdoid suture, lambdoid, or it may be u ...

(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 caus ...

(Q67.3) **

Scaphocephaly Scaphocephaly or sagittal craniosynostosis is a type of cephalic disorder which occurs when there is a premature fusion of the sagittal suture. Premature closure results in limited lateral expansion of the skull, resulting in a characteristic ...

(Q75.0) **

Trigonocephaly Trigonocephaly is a congenital condition due to premature Synostosis, fusion of the metopic suture (), leading to a triangular forehead. The premature 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 ...

(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

's public domain resource.''

References

External links

{{Medical resources , ICD11 = {{ICD11, LA00, {{ICD11, LA05 , ICD10 = {{ICD10, Q00-{{ICD10, Q04, {{ICD10, Q18, {{ICD10, Q67, {{ICD10, Q75, {{ICD10, 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