Neural System - Abnormalities

Embryology - 18 Apr 2024        Expand to Translate
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Introduction

Australian abnormalities (1981-92)

Neural groove closing to neural tube, early week 4
(Stage 10)

There are many different congenital and environmentally derived abnormalities associated with the nervous system. There are potentially 1000's of neurological abnormalities that could be listed on this page, therefore this current page is only a very brief introduction to some of these neural abnormalities. For additional information see links at the bottom of each sub-heading.

As the nervous system continues to develop fetally and postnatally, environmental issues both before and after birth are relevant to neural development. Embryonic and fetal nutrition folate (required early for neural tube closure) and iodine (required later for neural growth and differentiation). The developmental environment can also impact upon neural growth; maternal drugs such as alcohol and heavy metals such as lead (mining, historically both petrol and paint). Finally, postnatally other sensory abnormalities (hearing) can also impact on achieving developmental milestones.

| Low Folic Acid and NTDs | International Classification of Diseases - Neural

Some Recent Findings

Identification of PCSK9 as a novel serum biomarker for the prenatal diagnosis of neural tube defects using iTRAQ quantitative proteomics "To identify candidate serum molecule biomarkers for the non-invasive early prenatal diagnosis of neural tube defects (NTDs), we employed an iTRAQ-based quantitative proteomic approach to analyze the proteomic changes in serum samples from embryonic day (E) 11 and E13 pregnant rats with spina bifida aperta (SBA) induced by all-trans retinoic acid. ...We observed the space-time expression changes of proprotein convertase subtilisin/kexin type 9 (PCSK9) at different stages of fetal development, including a marked decrease in the sera of NTD pregnancies and gradual increase in the sera of normal pregnancies with embryonic development." Mutations in genes encoding the glycine cleavage system predispose to neural tube defects in mice and humans "Function of folate one-carbon metabolism (FOCM) has been implicated as a key determinant of susceptibility to NTDs. The glycine cleavage system (GCS) is a multi-enzyme component of mitochondrial folate metabolism, and GCS-encoding genes therefore represent candidates for involvement in NTDs. To investigate this possibility, we sequenced the coding regions of the GCS genes: AMT, GCSH and GLDC in NTD patients and controls. ... Overall, our findings suggest that loss-of-function mutations in GCS genes predispose to NTDs in mice and humans. These data highlight the importance of adequate function of mitochondrial folate metabolism in neural tube closure." Prenatal Diagnosis A randomized trial of prenatal versus postnatal repair of myelomeningoce "Prenatal repair of myelomeningocele, the most common form of spina bifida, may result in better neurologic function than repair deferred until after delivery. We compared outcomes of in utero repair with standard postnatal repair. ....Prenatal surgery for myelomeningocele reduced the need for shunting and improved motor outcomes at 30 months but was associated with maternal and fetal risks. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00060606.)." (see also paper comments) Australia 1998–2005 "944 births over this period affected by NTD. Of these births, 523 were live births and 421 were fetal deaths (still births and terminations after 20 weeks gestation). This equates to a prevalence of neural tube defects (NTD) among births of 4.6 per 10,000."

More recent papers

This table allows an automated computer search of the external PubMed database using the listed "Search term" text link. This search now requires a manual link as the original PubMed extension has been disabled. The displayed list of references do not reflect any editorial selection of material based on content or relevance. References also appear on this list based upon the date of the actual page viewing. References listed on the rest of the content page and the associated discussion page (listed under the publication year sub-headings) do include some editorial selection based upon both relevance and availability. More? References | Discussion Page | Journal Searches | 2019 References | 2020 References Search term: Abnormal Neural Development <pubmed limit=5>Abnormal Neural Development</pubmed>

Neural Tube Closure

Mouse mutant showing neural tube closure defect

Dysraphism is the term often used to describe the defective fusion of the neural folds. The position and degree of failure of fusion will result in either embryonic death or a range of different neural defects. The way (mode) in which the human neural tube fuses has been a source of contention. In humans, fusion appears to initiate at multiple sites along the neural groove , this mode of closure may differ from that found in many animal species used in developmental studies.

Human Embryonic Death:

• 5 weeks with total failure of fusion.
• 6.5 weeks with opening over the rhombencephalon.
• survive beyond 7 weeks with a defect at the frontal and parietal regions.

Mouse posterior neuropore Axd mutant

Links: Folic Acid and Neural Tube Defects

Spina Bifida (Meningomyelocele)

Spina Bifida and Anencephaly (dorsal view)

Double meningomyelocele

Meningomyelocele	Spina Bifida Rates (USA Data)

There are potentially many different causes of spina bifida and neural tube defects. The basis of the abnormality is a failure of the neural tube to close caudally. At least one known cause is a low maternal diet of folic acid (folate) containing foods. (see Neural Tube Defects and Low Folic Acid or Folic Acid below)

Neural tube defects from failure to close can be screened by amniocentesis or ultrasound.

Alpha-fetoproetin normally present in the CSF, leaks and can be detected in amniotic fluid.

International Classification of Diseases

Q05 Spina bifida Incl.: hydromeningocele (spinal), meningocele (spinal), meningomyelocele, myelocele, myelomeningocele, rachischisis, spina bifida (aperta)(cystica), syringomyelocele Excl.: Arnold-Chiari syndrome (Q07.0), spina bifida occulta (Q76.0) Q05.0 Cervical spina bifida with hydrocephalus Q05.1 Thoracic spina bifida with hydrocephalus Spina bifida: dorsal thoracolumbar with hydrocephalus Q05.2 Lumbar spina bifida with hydrocephalus, Lumbosacral spina bifida with hydrocephalus Q05.3 Sacral spina bifida with hydrocephalus Q05.4 Unspecified spina bifida with hydrocephalus Q05.5 Cervical spina bifida without hydrocephalus Q05.6 Thoracic spina bifida without hydrocephalus Spina bifida: dorsal NOS, thoracolumbar NOS Q05.7 Lumbar spina bifida without hydrocephalus, Lumbosacral spina bifida NOS Q05.8 Sacral spina bifida without hydrocephalus Q05.9 Spina bifida, unspecified

Links: Folic Acid and Neural Tube Defects

Cephalic Disorders

Cephalic (Greek, kephale = head) are a large group of abnormalities that relate to both skeletal (skull) and neural (brain) associated defects including: anencephaly, hydrocephalus, encephalocele, colpocephaly (occipital horn enlargement), lissencephaly (smooth brain), porencephaly (cyst or cavity in cerebral hemisphere), acephaly (absence of head), exencephaly (brain outside skull), macrocephaly (large head), micrencephaly (small brain), otocephaly (absence of lower jaw), brachycephaly (premature fusion of coronal suture), oxycephaly (premature fusion of coronal suture + other), plagiocephaly (premature unilateral fusion of coronal or lambdoid sutures), scaphocephaly (premature fusion of sagittal suture), trigonocephaly.

Microcephaly

Skull - microcephaly

A recent Spanish study has shown a concordance between a head circumference growth function and intellectual disability in relation with the cause of microcephaly.

"3,269 head circumference (HC) charts of patients from a tertiary neuropediatric unit were reviewed and 136 microcephalic participants selected. Using the Z-scores of registered HC measurements we defined the variables: HC Minimum, HC Drop and HC Catch-up. We classified patients according to the presence or absence of intellectual disability (IQ below 71) and according to the cause of microcephaly (idiopathic, familial, syndromic, symptomatic and mixed). Using Discriminant Analysis a C-function was defined as C=HC Minimum + HC Drop with a cut-off level of C=-4.32 Z-score. In our sample 95% of patients scoring below this level, severe microcephaly, were classified in the disabled group while the overall concordance was 66%. In the symptomatic-mixed group the concordance between HC function and outcome reached 82% in contrast to only 54% in the idiopathic-syndromic group (P-value=0.0002)."

Microlissencephaly (MRI) - Zika virus associated lishencephaly (smooth brain) in combination with severe congenital microcephaly (small head).

Anencephaly

Anencephaly Rates (USA Data)

This is a neural tube defect, the basis of the abnormality is a failure of the neural tube to close cranially. Also called exencephaly or craniorachischisis.

International Classification of Diseases
Q00 Anencephaly and similar malformations Q00.0 Anencephaly, Acephaly, Acrania, Amyelencephaly, Hemianencephaly, Hemicephaly Q00.1 Craniorachischisis Q00.2 Iniencephaly

Fetal Anencephaly
ventral view	lateral view

Anencephaly in a fetus (GA week 18) from a diabetic mother. Ultrasound images (coronal) show a complete absence of the cranial vault and brain and enlarged orbits.

Anencephaly Historic Drawings

These drawings are from a 1921 study of a single embryonic anencephaly.

• 

  Fig. 1. Reconstruction of anencephalic embryo.

• 

  Fig. 2. Hind-brain 28 mm embryo (left view).

These drawings are from a 1925 study of 57 cases of anencephaly.

• 

  anencephalic acranius

• 

  anencephalic craniorhachischisis

• 

  microcephalic acrauius

• 

  microcephalic craniorhachischisis

• 

  exocephalic acranius

Links: Maternal Diabetes

Holoprosencephaly

International Classification of Diseases - Q04 Other congenital malformations of brain - Q04.2 Holoprosencephaly

Below are shown images of fetal holoprosencephaly and associated cyclopia.

Human holoprosencephaly cyclopean dissection	Proboscis histology

Hydrocephalus

Hydrocephalus (historic image from Hess, 1922)

This is a defect of cerebrospinal fliud (CSF) flow, excess fluid production or impaired fluid absorption and can be congenital or acquired. Estimated incidence of 1 in 1000 live births the condition leads to enlarged ventricles and head, separated skull cranial sutures and fontanelles. Obstruction of CSF flow can occur at any time (prenatally or postnatally) and leads to accumulation of within the ventricles. The time of onset will have different effects and should be compared to the equilivant neurological events that are occuring.

Ventricular obstruction usually occurs at the level of the cerebral aqueduct (narrowest site), but can occur elsewhere, and can be caused by viral infection or zoonotic disease.

Links: Congenital Hydrocephalus

Dandy Walker malformation

Dandy Walker malformation (MRI) is another form of ventricular abnormality that affects cerebellar development. The vermis of the cerebellum can be small or absent, the fourth ventricle enlarges due to cyst formation. An ultrasound studyof fetuses with Dandy-Walker malformation 13 to 16 weeks (GA 15-18 weeks) identified the fourth ventricle widely open posteriorly, even in the standard transcerebellar view, and the brainstem-vermis (BV) angle was > 45°, significantly increased compared to that in normal fetuses (P < 0.0001). Note that at this age, an open fourth ventricle can also found in about 10% of normal fetuses. Named after Walter Dandy (1886 – 1946) and Arthur Earl Walker (1907 – 1995), two USA neurosurgeons.  ‎‎Dandy-Walker Page | Play

Links: Congenital Hydrocephalus

Encephalocele

This defect is generally mesodermal in origin, leading to protrusion of brain and meninges outside the crainal cavity. The severity of the disorder can vary dependent upon the degree of mesodermal abnormality.

Encephalitis

Normally a postnatal clinical syndrome of the central nervous system resulting in inflammation of the brain parenchyma and caused by a range of pathogens (viral, bacterial and protozoal infections). This infectious disease is due mainly to viral pathogens: Herpes simplex encephalitis 10%–20% of cases, Murray Valley encephalitis virus, Japanese encephalitis virus, Australian bat lyssavirus, West Nile virus, Hendra virus and Nipah virus. The pathogen is generally included in the specific encephalitis naming; Varicella encephalitis and Toxoplasma meningoencephalitis.

Links: Neural System - Abnormalities | TORCH Infections | PMC2700670)

Fragile X Syndrome

Fragile X Syndrome (FXS) is the most common form of inherited mental retardation and autism. The condition is caused by a loss of the functional fragile X mental retardation protein (FMRP) an RNA-binding protein that can regulate the translation of specific mRNAs. There are several suggested additional roles for this protein including synaptic development and function and in adult neurogenesis.

ICD: Q99.2 Fragile X chromosome Fragile X syndrome

Links: Fragile X Syndrome

Autism

Autism (autism spectrum disorder, ASD) is a behaviourally defined brain disorder in children. Features include: impoverished verbal and non-verbal communication skills, reduced social interactions (bias their attention towards objects rather than the surrounding social situation), behavioural impairments in attention engagement/disengagement, poor emotional discrimination and facial recognition, and fail to response to their own names. There exist many different and unproven claims as to the origins of autism.

Developmentally associated with neural maturation changes in cortical thickness and organization, and particularly affecting pyramidal neurons. A rat model shows structural and behavioural features of autism as a result of altering the trajectory of early postnatal cortical development.

Links: Neural Exam Movies

Rett Syndrome

(RTT) A severe neurodevelopment disorder, with intellectual disability and abnormalities of movement, mainly caused by mutations in the X-linked (Xq28) Methyl-CpG-binding protein 2 (MECP2) gene and therefore almost exclusively in females. The congenital variant of Rett syndrome is caused by heterozygous mutation in the FOXG1 gene on chromosome 14q13.

Links: OMIM - Congenital Rett syndrome | OMIM - Rett syndrome

Cerebral Palsy

ICD-10 G80 Cerebral palsy

G80 Cerebral palsy (Excl.: hereditary spastic paraplegia (G11.4) G80.0 Spastic quadriplegic cerebral palsy; Spastic tetraplegic cerebral palsy G80.1 Spastic diplegic cerebral palsy; Congenital spastic paralysis (cerebral); Spastic cerebral palsy NOS G80.2 Spastic hemiplegic cerebral palsy G80.3 Dyskinetic cerebral palsy; Athetoid cerebral palsy; Dystonic cerebral palsy G80.4 Ataxic cerebral palsy G80.8 Other cerebral palsy; Mixed cerebral palsy syndromes G80.9 Cerebral palsy, unspecified Links: Cerebral palsy | Cerebral palsy and other paralytic syndromes G80-G83 | ICD-10 | International Classification of Diseases

Cerebral palsy is a group of disorders in motor impairment that limits activity, and is attributed to non-progressive disturbances during brain development in fetuses or infants (3-4 / 1,000).

Represented by one or more of these features:

• impaired cognition
• impaired communication
• impaired sensory perception
• behavioural abnormalities
• seizure disorders

Links: Neural Exam Movies | Medline Plus | NINDS - Info | CDC Screening and Diagnosis | Cerebral Palsy Alliance

Newborn Neural Exam

Neural - The collapsed tables below link to a number of short videos that demonstrate simple assessments of the postnatal developing nervous system.

Normal 3 Month Neural Exam Movies Normal 3 Month Neural Exam Movies The neuromuscular system can be initially assessed by 6 quick tests (posture, square window, arm recoil, popliteal angle, scarf sign and heel to ear). The following short videos show clinical examination of these assessments and a number of reflexes. Later developmental assessment includes behaviour, reflexes (primitive and postural), muscular tone, and motor (gross, fine, co-ordination). 3 Months Neural Exam Movies: normal behaviour | cranial nerves | Tone - head and trunk control | upper extremity‎ | hand movements | lower extremity Positions - supine | prone | ventral suspension | vertical suspension | Reflexes - Deep tendon reflexes | Plantar reflex‎ | Root | Moro | Galant | Grasp | Asymmetric tonic neck‎ | Neural Exam Movies | Neonatal Diagnosis 3 Month Behaviour  ‎‎Behaviour Page | Play  ‎‎Cranial Nerves Page | Play normal behaviour cranial nerves 3 Month Tone  ‎‎Control Page | Play  ‎‎Tone Upper Limb Page | Play  ‎‎Hand Movements Page | Play  ‎‎Lower Limb Page | Play 3 Month Positions  ‎‎Supine Position Page | Play  ‎‎Prone Position Page | Play  ‎‎Ventral Suspension Page | Play  ‎‎Vertical Suspension Page | Play 3 Month Reflexes  ‎‎Deep Tendon Page | Play  ‎‎Plantar Reflex Page | Play  ‎‎Suck-Root Page | Play  ‎‎Moro Reflex Page | Play  ‎‎Galant Reflex Page | Play  ‎‎Grasp Reflex Page | Play  ‎‎Neck Tone Page | Play 3 Months Neural Exam Movies: normal behaviour | cranial nerves | Tone - head and trunk control | upper extremity‎ | hand movements | lower extremity Positions - supine | prone | ventral suspension | vertical suspension | Reflexes - Deep tendon reflexes | Plantar reflex‎ | Root | Moro | Galant | Grasp | Asymmetric tonic neck‎ | Neural Exam Movies | Neonatal Diagnosis

Normal 12 Month Neural Exam Movies   Normal 12 Month Neural Exam Movies The following short videos show clinical examination of neural development assessments and a number of reflexes. 12 Months Neural Exam Movies: Shy | Social and Language | Cranial Nerves | Tone - Tone | Reflexes - deep tendon reflexes | plantar reflex‎ | Parachute | Pincer Grasp | Beads in the Cup | Play Ball | Transition in and out of Sitting | Creeping | Stoop and Recover | Motor/Gait - Stand, Walks with Support | Toddler’s Gait | Head Circumference | Neural Exam Movies

Normal 18 Month Neural Exam Movies Normal 18 Month Neural Exam Movies The following short videos show clinical examination of neural development assessments and a number of reflexes. Neural Exam Movies: Wants | Understanding | Points to Pictures | Points to Body Parts | Cranial Nerves Motor/Coordination - Blocks in Cup | Beads in Cup | Stacking Blocks | Pincer Grasp and Handedness | Drawing/Scribbling | Tone | Deep Tendon Reflex | Throwing Ball | Walking

Normal 30 Month Neural Exam Movies   Normal 30 Month Neural Exam Movies The following short videos show clinical examination of neural development assessments and a number of reflexes. Neural Exam Movies: Establishing Relationship | Follows Commands | Points to Pictures | Names Pictures | Response to Questions | Pointing to and Naming Body Parts | Motor/Coordination - Using Puppets | Using Measuring Tape | Block Tower | Drawing | Tone | Deep Tendon Reflex | Kicking and Throwing a Ball | Walking, Running

Links: Neural Exam Movies | Neural Exam Movies -Newborn Abnormal

International Classification of Diseases

The International Classification of Diseases (ICD) World Health Organization's classification used worldwide as the standard diagnostic tool for epidemiology, health management and clinical purposes. This includes the analysis of the general health situation of population groups. It is used to monitor the incidence and prevalence of diseases and other health problems. Within this classification "congenital malformations, deformations and chromosomal abnormalities" are (Q00-Q99) but excludes "inborn errors of metabolism" (E70-E90).

Note that the current ICD10 classification system is being updated to ICD11 that is currently in beta testing status. The data on this page, other than the information in the collapsed table below, is from ICD10 classification.

International Classification of Diseases  ICD-11 20 Developmental anomalies (beta draft)
ICD-11 Beta Draft - NOT FINAL, updated on a daily basis, It is not approved by WHO, NOT TO BE USED for CODING except for agreed FIELD TRIALS. Chapter 20 Developmental anomalies, only a few examples of the draft ICD-11 Beta coding and tree structure for "structural developmental anomalies" within this section are shown in the table below.
Mortality and Morbidity Statistics - 20 Developmental Anomalies
Structural Developmental Anomalies   Structural developmental anomalies of the nervous system   LA00 Anencephaly or similar anomalies LA01 Cephalocele LA02 Spina bifida LA03 Arnold-Chiari malformation type II LA04 Congenital hydrocephalus LA05 Cerebral structural developmental anomalies LA06 Cerebellar structural developmental anomalies LA07 Structural developmental anomalies of the neurenteric canal, spinal cord or vertebral column LA0Y Other specified structural developmental anomalies of the nervous system LA0Z Structural developmental anomalies of the nervous system, unspecified Structural developmental anomalies of the eye, eyelid or lacrimal apparatus LA10 Structural developmental anomalies of ocular globes LA11 Structural developmental anomalies of the anterior segment of eye LA30 Structural developmental anomalies of lens or zonula LA31 Structural developmental anomalies of the posterior segment of eye LA32 Structural developmental anomalies of eyelid, lacrimal apparatus or orbit LA3Y Other specified structural developmental anomalies of the eye, eyelid or lacrimal apparatus LA3Z Structural developmental anomalies of the eye, eyelid or lacrimal apparatus, unspecified Structural developmental anomalies of the ear   LA40 Structural anomaly of eustachian apparatus LA41 Minor anomalies of pinnae LA42 Structural developmental anomalies of ear causing hearing impairment LA43 Otocephaly LA44 Accessory auricle LA4Y Other specified structural developmental anomalies of the ear LA4Z Structural developmental anomalies of the ear, unspecified Structural developmental anomalies of the face, mouth or teeth LA50 Structural developmental anomalies of teeth and periodontal tissues LA51 Structural developmental anomalies of mouth or tongue Clefts of lip, alveolus or palate LA70 Congenital velopharyngeal incompetence LA71 Facial clefts LA72 Facial asymmetry LA73 Macrocheilia LA74 Microcheilia LA75 Compression facies LA76 Pierre Robin syndrome LC20 Dermoid cyst LA7Y Other specified structural developmental anomalies of the face, mouth or teeth LA7Z Structural developmental anomalies of the face, mouth or teeth, unspecified Structural developmental anomalies of the neck   Structural developmental anomalies of the respiratory system   Structural developmental anomalies of the circulatory system   Structural developmental anomaly of heart and great vessels LB00 Congenital heart or great vessel related acquired abnormality LB01 Congenital anomaly of atrioventricular or ventriculo-arterial connections LB02 Congenital anomaly of the mediastinal veins Congenital anomaly of atria or atrial septum LB20 Congenital anomaly of atrioventricular valves or septum LB21 Congenital anomaly of ventricles and ventricular septum LB22 Functionally univentricular heart LB23 Congenital anomaly of ventriculo-arterial valves and adjacent regions LB24 Congenital anomaly of great arteries including arterial duct LB25 Anomalous position-orientation of heart LB26 Total mirror imagery LB27 Left isomerism LB28 Congenital anomaly of coronary arteries LB29 Structural developmental anomalies of the pericardium LB2Y Other specified structural developmental anomaly of heart and great vessels LB2Z Structural developmental anomaly of heart and great vessels, unspecified LB30 Structural developmental anomalies of the peripheral vascular system LB30.1 Capillary malformations LB30.2 Lymphatic malformations LB30.21 Macrocystic lymphatic malformation LB30.22 Microcystic lymphatic malformation LB30.23 Cystic hygroma in fetus BD23.1 Primary lymphoedema EK91 Yellow nail syndrome LC5F.26 Noonan syndrome LB30.2Y Other specified lymphatic malformations LB30.2Z Lymphatic malformations, unspecified LB30.3 Peripheral venous malformations LB30.4 Peripheral arteriovenous malformations LB30.5 Peripheral arterial malformations LB30.6 Pulmonary arteriovenous fistula LB30.Y Other specified structural developmental anomalies of the peripheral vascular system LB30.Z Structural developmental anomalies of the peripheral vascular system, unspecified LB3Y Other specified structural developmental anomalies of the circulatory system LB3Z Structural developmental anomalies of the circulatory system, unspecified Structural developmental anomalies of the diaphragm, abdominal wall or umbilical cord   Structural developmental anomalies of the digestive tract   Structural developmental anomalies of the liver, biliary tract, pancreas or spleen   Structural developmental anomalies of the urinary system   Structural developmental anomalies of the female genital system   Structural developmental anomalies of the male genital system   Structural developmental anomalies of the breast   Structural developmental anomalies of the skeleton   Structural developmental anomalies of the skin   Structural developmental anomalies of the adrenal glands
Multiple developmental anomalies or syndromes
Chromosomal anomalies, excluding gene mutations
Conditions with disorders of intellectual development as a relevant clinical feature
LD6Y Other specified developmental anomalies LD6Z Developmental anomalies, unspecified
CD-11 Beta Draft - NOT FINAL, updated on a daily basis, It is not approved by WHO, NOT TO BE USED for CODING except for agreed FIELD TRIALS. See also International Classification of Diseases ICD-10

Congenital malformations of the nervous system (Q00-Q07)

Links: Neural System - Abnormalities | Neural Crest Abnormalities | WHO Links

Q00 Anencephaly and similar malformations

• Q00.0 Anencephaly, Acephaly, Acrania, Amyelencephaly, Hemianencephaly, Hemicephaly
• Q00.1 Craniorachischisis
• Q00.2 Iniencephaly

Q01 Encephalocele

Incl.: encephalomyelocele, hydroencephalocele, hydromeningocele, cranial meningocele, cerebral meningoencephalocele

Excl.: Meckel-Gruber syndrome (Q61.9)

• Q01.0 Frontal encephalocele
• Q01.1 Nasofrontal encephalocele
• Q01.2 Occipital encephalocele
• Q01.8 Encephalocele of other sites
• Q01.9 Encephalocele, unspecified

Q02 Microcephaly

Incl.: Hydromicrocephaly Micrencephalon Excl.: Meckel-Gruber syndrome (Q61.9)

Q03 Congenital hydrocephalus

Q03 Congenital hydrocephalus Incl.: hydrocephalus in newborn Excl.: Arnold-Chiari syndrome (Q07.0) hydrocephalus: acquired (G91.-) due to congenital toxoplasmosis (P37.1) with spina bifida (Q05.0-Q05.4)

• Q03.0 Malformations of aqueduct of Sylvius Aqueduct of Sylvius: anomaly obstruction, congenital stenosis
• Q03.1 Atresia of foramina of Magendie and Luschka Dandy-Walker syndrome
• Q03.8 Other congenital hydrocephalus
• Q03.9 Congenital hydrocephalus, unspecified

Q04 Other congenital malformations of brain

Excl.: cyclopia (Q87.0) macrocephaly (Q75.3)

• Q04.0 Congenital malformations of corpus callosum, Agenesis of corpus callosum
• Q04.1 Arhinencephaly
• Q04.2 Holoprosencephaly
• Q04.3 Other reduction deformities of brain, Absence, Agenesis, Aplasia, Hypoplasia of part of brain, Agyria, Hydranencephaly, Lissencephaly, Microgyria, Pachygyria Excl.: congenital malformations of corpus callosum (Q04.0)
• Q04.4 Septo-optic dysplasia
• Q04.5 Megalencephaly
• Q04.6 Congenital cerebral cysts, Porencephaly, Schizencephaly, Excl.: acquired porencephalic cyst (G93.0)
• Q04.8 Other specified congenital malformations of brain, Macrogyria
• Q04.9 Congenital malformation of brain, unspecified Congenital: anomaly, deformity, disease or lesion, multiple anomalies NOS of brain

Q05 Spina bifida

Incl.: hydromeningocele (spinal), meningocele (spinal), meningomyelocele, myelocele, myelomeningocele, rachischisis, spina bifida (aperta)(cystica), syringomyelocele Excl.: Arnold-Chiari syndrome (Q07.0), spina bifida occulta (Q76.0)

• Q05.0 Cervical spina bifida with hydrocephalus
• Q05.1 Thoracic spina bifida with hydrocephalus Spina bifida: dorsal thoracolumbar with hydrocephalus
• Q05.2 Lumbar spina bifida with hydrocephalus, Lumbosacral spina bifida with hydrocephalus
• Q05.3 Sacral spina bifida with hydrocephalus
• Q05.4 Unspecified spina bifida with hydrocephalus
• Q05.5 Cervical spina bifida without hydrocephalus
• Q05.6 Thoracic spina bifida without hydrocephalus Spina bifida: dorsal NOS, thoracolumbar NOS
• Q05.7 Lumbar spina bifida without hydrocephalus, Lumbosacral spina bifida NOS
• Q05.8 Sacral spina bifida without hydrocephalus
• Q05.9 Spina bifida, unspecified

Q06 Other congenital malformations of spinal cord

• Q06.0 Amyelia
• Q06.1 Hypoplasia and dysplasia of spinal cord, Atelomyelia, Myelatelia, Myelodysplasia of spinal cord
• Q06.2 Diastematomyelia
• Q06.3 Other congenital cauda equina malformations
• Q06.4 Hydromyelia Hydrorachis
• Q06.8 Other specified congenital malformations of spinal cord
• Q06.9 Congenital malformation of spinal cord, unspecified Congenital: anomaly, deformity, disease or lesion, NOS of spinal cord or meninges

Q07 Other congenital malformations of nervous system

Excl.: familial dysautonomia [Riley-Day] (G90.1), neurofibromatosis (nonmalignant) (Q85.0)

• Q07.0 Arnold-Chiari syndrome
• Q07.8 Other specified congenital malformations of nervous system Agenesis of nerve, Displacement of brachial plexus, Jaw-winking syndrome, Marcus Gunn's syndrome
• Q07.9 Congenital malformation of nervous system, unspecified Congenital: anomaly, deformity, disease or lesion, NOS of nervous system

Links: XVII Congenital Malformations | International Classification of Diseases

References

Journals

Journal of Pediatric Neurosciences - is official publication of the Indian Society for Pediatric Neurosurgery.

Search PubMed

Search term: Neural Development Abnormalities | Anencephaly | Hydrocephalus | Encephalocele | Holoprosencephaly | Autism

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Cite this page: Hill, M.A. (2024, April 18) Embryology Neural System - Abnormalities. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Neural_System_-_Abnormalities

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