Spina bifida with Myelocele is the most severe form of myelomeningocele. In this type, the involved area is represented by a flattened, plate-like mass of nervous tissue with no overlying membrane. The exposure of these nerves and tissues make the baby more prone to life-threatening infections such as meningitis.

The protruding portion of the spinal cord and the nerves that originate at that level of the cord are damaged or not properly developed. As a result, there is usually some degree of paralysis and loss of sensation below the level of the spinal cord defect. Thus, the more cranial the level of the defect, the more severe the associated nerve dysfunction and resultant paralysis may be. Symptoms may include ambulatory problems, loss of sensation, deformities of the hips, knees or feet, and loss of muscle tone.

Physical signs of spina bifida may include:

- Leg weakness and paralysis

- Orthopedic abnormalities (i.e., club foot, hip dislocation, scoliosis)

- Bladder and bowel control problems, including incontinence, urinary tract infections, and poor kidney function

- Pressure sores and skin irritations

- Abnormal eye movement

68% of children with spina bifida have an allergy to latex, ranging from mild to life-threatening. The common use of latex in medical facilities makes this a particularly serious concern. The most common approach to avoid developing an allergy is to avoid contact with latex-containing products such as examination gloves and condoms and catheters that do not specify they are latex-free, and many other products, such as some commonly used by dentists.

The spinal cord lesion or the scarring due to surgery may result in a tethered spinal cord. In some individuals, this causes significant traction and stress on the spinal cord and can lead to a worsening of associated paralysis, scoliosis, back pain, and worsening bowel and/or bladder function.

Encephaloceles are characterized by protrusions of the brain through the skull that are sac-like and covered with membrane. They can be a groove down the middle of the upper part of the skull, between the forehead and nose, or the back of the skull. Encephaloceles are often obvious and diagnosed immediately. Sometimes small encephaloceles in the nasal and forehead are undetected.

Anencephaly (without brain) is a neural tube defect that occurs when the head end of the neural tube fails to close, usually during the 23rd and 26th days of pregnancy, resulting in an absence of a major portion of the brain and skull. Infants born with this condition are born without the main part of the forebrain—the largest part of the cerebrum—and are usually blind, deaf and unconscious. The lack of a functioning cerebrum will ensure that the infant will never gain consciousness. Infants are either stillborn or usually die within a few hours or days after birth.

Vertebral anomalies is associated with an increased incidence of some other specific anomalies as well, together being called the VACTERL association:

- V - "Vertebral anomalies"

- A - Anal atresia

- C - Cardiovascular anomalies

- T - Tracheoesophageal fistula

- E - Esophageal atresia

- R - Renal (Kidney) and/or radial anomalies

- L - Limb defects

The signs and symptoms of diastematomyelia may appear at any time of life, although the diagnosis is usually made in childhood. Cutaneous lesions (or stigmata), such as a hairy patch, dimple, Hemangioma, subcutaneous mass, Lipoma or Teratoma override the affected area of the spine is found in more than half of cases. Neurological symptoms are nonspecific, indistinguishable from other causes of cord tethering. The symptoms are caused by tissue attachments that limit the movement of the spinal cord within the spinal column. These attachments cause an abnormal stretching of the spinal cord.

The course of the disorder is progressive. In children, symptoms may include the "stigmata" mentioned above and/or foot and spinal deformities; weakness in the legs; low back pain; scoliosis; and incontinence. In adulthood, the signs and symptoms often include progressive sensory and motor problems and loss of bowel and bladder control. This delayed presentation of symptoms is related to the degree of strain placed on the spinal cord over time.

Tethered spinal cord syndrome appears to be the result of improper growth of the neural tube during fetal development, and is closely linked to spina bifida.

Tethering may also develop after spinal cord injury and scar tissue can block the flow of fluids around the spinal cord. Fluid pressure may cause cysts to form in the spinal cord, a condition called syringomyelia. This can lead to additional loss of movement, feeling or the onset of pain or autonomic symptoms.

Cervical diastematomyelia can become symptomatic as a result of acute trauma, and can cause major neurological deficits, like hemiparesis, to result from otherwise mild trauma.

The following definitions may help to understand some of the related entities:

- Diastematomyelia (di·a·stem·a·to·my·elia) is a congenital anomaly, often associated with spina bifida, in which the spinal cord is split into halves by a bony spicule or fibrous band, each half being surrounded by a dural sac.

- Myeloschisis (my·elos·chi·sis) is a developmental anomaly characterized by a cleft spinal cord, owing to failure of the neural plate to form a complete neural tube or to rupture of the neural tube after closure.

- Diplomyelia (diplo.my.elia) is a true duplication of spinal cord in which these are two dural sacs with two pairs of anterior and posterior nerve roots.

The blockage of cerebrospinal fluid (CSF) flow may also cause a syrinx to form, eventually leading to syringomyelia. Central cord symptoms such as hand weakness, dissociated sensory loss, and, in severe cases, paralysis may occur.

Syringomyelia is a chronic progressive degenerative disorder characterized by a fluid-filled cyst located in the spinal cord. Its symptoms include pain, weakness, numbness, and stiffness in the back, shoulders, arms or legs. Other symptoms include headaches, the inability to feel changes in the temperature, sweating, sexual dysfunction, and loss of bowel and bladder control. It is usually seen in the cervical region but can extend into the medulla oblongata and pons or it can reach downward into the thoracic or lumbar segments. Syringomyelia is often associated with Chiari malformation type I and is commonly seen between the C-4 and C-6 levels. The exact development of syringomyelia is unknown but many theories suggest that the herniated tonsils in Chiari malformation type I form a "plug" which does not allow an outlet of CSF from the brain to the spinal canal. Syringomyelia is present in 25% of patients with Chiari malformation.

In children, symptoms may include:

- Lesions, hairy patches, dimples, or fatty tumours on the lower back

- Foot and spinal deformities

- Weakness in the legs (loss of muscle strength and tone)

- Change in or abnormal gait including awkwardness while running or wearing the tips or side of one shoe

- Low back pain

- Scoliosis (abnormal curvature of the spine to the left or right)

- Urinary irregularities (incontinence or retention)

Tethered spinal cord syndrome may go undiagnosed until adulthood, when sensory, motor, bowel, and bladder control issues emerge. This delayed presentation of symptoms relates to the degree of strain on the spinal cord over time.

Tethering may also develop after spinal cord injury. Scar tissue can block the flow of fluids around the spinal cord. Fluid pressure may cause cysts to form in the spinal cord, a condition called syringomyelia. This can lead to additional loss of movement or feeling, or the onset of pain or autonomic nervous system symptoms.

In adults, onset of symptoms typically include:

- Severe pain (in the lower back and radiating into the legs, groin, and perineum)

- Bilateral muscle weakness and numbness

- Loss of feeling and movement in lower extremities

- Urinary irregularities (incontinence or retention)

- Bowel control issues

Neurological symptoms can include a mixed picture of upper and lower motor neuron findings, such as amyotrophy, hyperreflexia, and pathologic plantar response, occurring in the same limb. Profound sensory changes, such as loss of pain, temperature, and proprioceptive sensations, are common. Last, progressive symptoms of a neuropathic bladder are noted on over 70% of adult patients, versus only 20% to 30% of children. These symptoms include urinary frequency and urgency, feeling of incomplete voiding, poor voluntary control, and urge and stress incontinence. Chronic recurrent infections are common and occasionally lead to nephrolithiasis (kidney stones), renal failure, or renal transplantation. Female patients also give a history of ineffective labor and postpartum rectal prolapse, presumably due to an atonic pelvic floor.

Hemivertebrae are wedge-shaped vertebrae and therefore can cause an angle in the spine (such as kyphosis, scoliosis, and lordosis).

Among the congenital vertebral anomalies, hemivertebrae are the most likely to cause neurologic problems. The most common location is the midthoracic vertebrae, especially the eighth (T8). Neurologic signs result from severe angulation of the spine, narrowing of the spinal canal, instability of the spine, and luxation or fracture of the vertebrae. Signs include rear limb weakness or paralysis, urinary or fecal incontinence, and spinal pain. Most cases of hemivertebrae have no or mild symptoms, so treatment is usually conservative. Severe cases may respond to surgical spinal cord decompression and vertebral stabilization.

Associations

Recognised associations are many and include:

Aicardi syndrome,

cleidocranial dysostosis,

gastroschisis 3,

Gorlin syndrome,

fetal pyelectasis 3,

Jarcho-Levin syndrome,

OEIS complex,

VACTERL association.

The probable cause of hemivertebrae is a lack of blood supply causing part of the vertebrae not to form.

Hemivertebrae in dogs are most common in the tail, resulting in a screw shape.

Diastematomyelia (occasionally diastomyelia) is a congenital disorder in which a part of the spinal cord is split, usually at the level of the upper lumbar vertebra.

Diastematomyelia is a rare congenital anomaly that results in the "splitting" of the spinal cord in a longitudinal (sagittal) direction. Females are affected much more commonly than males. This condition occurs in the presence of an osseous (bone), cartilaginous or fibrous septum in the central portion of the spinal canal which then produces a complete or incomplete sagittal division of the spinal cord into two hemicords. When the split does not reunite distally to the spur, the condition is referred to as a diplomyelia, or true duplication of the spinal cord.

Usually encephaloceles are noticeable deformities and are diagnosed immediately after birth, but a small encephalocele in the nasal or forehead region can go undetected. Various physical and mental developmental delays can indicate the presence of encephaloceles.

Encephaloceles are often accompanied by craniofacial abnormalities or other brain malformations. Symptoms may include neurologic problems, hydrocephalus (cerebrospinal fluid accumulated in the brain), spastic quadriplegia (paralysis of the limbs), microcephaly (an abnormally small head), ataxia (uncoordinated muscle movement), developmental delay, vision problems, mental and growth retardation, and seizures.

Additional symptoms include:

- anencephaly (failure of major sections of the brain to form)

- encephalocele (cranial contents protrudes from the skull)

- cyclopia (the two eye cavities fuse into one)

- agnathia

- cleft palate

- arthrogryposis

- clubfeet

- holoprosencephaly

- spina bifida

- low-set ears

- pulmonary hypoplasia

- omphalocele

- gastroschisis

- cardiovascular disorders

- diaphragmatic hernias

- gastrointestinal atresia

- single umbilical artery

- renal abnormalities

- genu recurvatum

- hydramnios

Tethered spinal cord can be caused by various conditions but the main cause is when tissue attachments limit the movement of the spinal cord in the spinal column which causes abnormal stretching of the cord. The tethered spinal cord syndrome is correlated with having the causes:

- Spina bifida

- Occulta

- Mylomeningocele

- Meningocele

- History of spinal trauma

- History of spinal surgery

- Tumor(s) in the spinal column

- Thickened and/or tight filum terminale

- Lipoma(s) in the spinal column

- Dermal Sinus Tract (congenital deformity)

- Diastematomyelia (split spinal cord)

Tethered spinal cord is a disorder and not a mechanism so it does not spread to other people and there are no measures that can be done to prevent it beforehand. The only preventative measure that is successful is to surgically untether the spinal cord though there might already be irreversible damage.

The following are clear signs of Kyphoscoliosis:

- Abnormal hunch along with a presence of S or C-like shape.

- Uneven lengths of arms and legs

- Presence of associated disorders likes hypertension, neurological disorders

- Abnormal gait

Scoliosis refers to yet another form of abnormal curvature in which the person’s spine takes an “S” or “C” shape. Scoliosis too has similar forms of treatments available as Kyphosis including bracing, physical therapy and various types of surgeries. Typically, a human spine is straight but in Scoliosis patients; there may be a curve of ten degrees in either direction, left or right.

The affected infant tends to be short, with a disproportionately large head. The fetal head of Infants born with iniencephaly are hyperextended while the foramen magnum is enlarged and opens through the widened pedicles. The defective neural arches directly into the upper cervical reach of the spinal canal, causing the formation of a common cavity between most of the spinal cord and the brain. The skin of the anterior chest is connected directly to the face, bypassing the formation of a neck, while the scalp is directly connected to the skin of the back. Because of this, those born with this anomaly either have a highly shortened neck or no neck at all. This causes extreme retroflexion, or backward bending, of the head in a "star-gazing" fashion. The spine is severely distorted as well along with significant shortening due to marked lordosis. The vertebrae, especially cervical, are fused together in abnormal shapes and their numbers are reduced. The spinal cord is almost always defective while the ventricular system is often dilated and the cortex is thinned. Sometimes, in the case of iniencephaly apertus, an encephalocele (sac-like protrusions of the brain through an opening in the cranium) forms.

Numerous associated abnormalities of other organ systems may be present. This heterogeneity requires comprehensive evaluation of all patients and treatment regimes that can vary from modification of activities to extensive spinal surgeries. Furthermore, it is unclear whether Klippel–Feil syndrome is a unique disease, or if it is one part of a spectrum of congenital spinal deformities. Klippel–Feil syndrome is usually diagnosed after birth.

The most common sign of the disorder is restricted mobility of the neck and upper spine. A short neck and low hairline at the back of the head may occur in some patients.

Associated abnormalities may include:

- scoliosis (side-to-side curvature of the spine), which is abnormal curving of the spine. The spine sometimes appears as a "C" or an "S"

- spina bifida, when the spinal canal and the back bone do not close completely during birth

- anomalies of the kidneys and the ribs

- cleft palate (hole in the roof of the mouth)

- dental problems (late dentition, high-risk of caries, oligo- and hypodontia)

- respiratory problems

- heart malformations

- short stature

- Duane syndrome

- Approximately 35% of patients with Klippel–Feil syndrome will also have a congenital elevation of the scapula known as Sprengel's deformity

The disorder also may be associated with abnormalities of the head and face, skeleton, sex organs, muscles, brain and spinal cord, arms, legs, fingers and heart defects. These heart defects often lead to a shortened life expectancy, the average being 35–45 years of age among males and 40–50 among females. This condition is similar to the heart failure seen in gigantism.

In 2011, a study identifying the occurrence of symptoms of 100 patients was published.

Spina bifida is the most common defect impacting the Central Nervous System (CNS). The most common and most severe form of Spina Bifida is Myelomeningocele. Individuals with Myelomeningocele are born with an incompletely fused spine, and therefore exposing the spinal cord through an opening in the back. In general, the higher the spinal lesion, the greater the functional impairment to the individual. Symptoms may include bowel and bladder problems, weakness and/or loss of sensation below the level of the lesion, paralysis, or orthopedic issues. Severity of symptoms can vary per situation.

A limb anomaly is called a dysmelia. These include all forms of limbs anomalies, such as amelia, ectrodactyly, phocomelia, polymelia, polydactyly, syndactyly, polysyndactyly, oligodactyly, brachydactyly, achondroplasia, congenital aplasia or hypoplasia, amniotic band syndrome, and cleidocranial dysostosis.

Congenital anomalies of the heart include patent ductus arteriosus, atrial septal defect, ventricular septal defect, and tetralogy of fallot.

Congenital anomalies of the nervous system include neural tube defects such as spina bifida, meningocele, meningomyelocele, encephalocele and anencephaly. Other congenital anomalies of the nervous system include the Arnold-Chiari malformation, the Dandy-Walker malformation, hydrocephalus, microencephaly, megalencephaly, lissencephaly, polymicrogyria, holoprosencephaly, and agenesis of the corpus callosum.

Congenital anomalies of the gastrointestinal system include numerous forms of stenosis and atresia, and perforation, such as gastroschisis.

Congenital anomalies of the kidney and urinary tract (CAKUT) include renal parenchyma, kidneys, and urinary collecting system.

Defects can be bilateral or unilateral, and different defects often coexist in an individual child

Congenital hydrocephalus is present in the infant prior to birth, meaning the fetus developed hydrocephalus in utero during fetal development. The most common cause of congenital hydrocephalus is aqueductal stenosis. Aqueductal stenosis occurs when the narrow passage between the third and fourth ventricles in the brain is blocked or too narrow to allow sufficient cerebral spinal fluid to drain. Fluid accumulates in the upper ventricles, causing hydrocephalus.

Other causes of congenital hydrocephalus include neural tube defects, arachnoid cysts, Dandy-Walker syndrome, and Arnold-Chiari malformation.

The cranial bones fuse by the end of the third year of life. For head enlargement to occur, hydrocephalus must occur before then. The causes are usually genetic but can also be acquired and usually occur within the first few months of life, which include 1) intraventricular matrix hemorrhages in premature infants, 2) infections, 3) type II Arnold-Chiari malformation, 4) aqueduct atresia and stenosis, and 5) Dandy-Walker malformation.

In newborns and toddlers with hydrocephalus, the head circumference is enlarged rapidly and soon surpasses the 97th percentile. Since the skull bones have not yet firmly joined together, bulging, firm anterior and posterior fontanelles may be present even when the patient is in an upright position.

The infant exhibits fretfulness, poor feeding, and frequent vomiting. As the hydrocephalus progresses, torpor sets in, and the infant shows lack of interest in their surroundings. Later on, the upper eyelids become retracted and the eyes are turned downwards ("sunset eyes") (due to hydrocephalic pressure on the mesencephalic tegmentum and paralysis of upward gaze). Movements become weak and the arms may become tremulous. Papilledema is absent but there may be a reduction of vision. The head becomes so enlarged that the child may eventually be bedridden.

About 80-90% of fetuses or newborn infants with spina bifida—often associated with meningocele or myelomeningocele—develop hydrocephalus.

Klippel–Feil syndrome is a rare disease, initially reported in 1884 by Maurice Klippel and André Feil from France, characterized by the congenital fusion of any two of the seven cervical vertebrae.

The syndrome occurs in a heterogeneous group of patients unified only by the presence of a congenital defect in the formation or segmentation of the cervical spine. Klippel-Feil results in limited movement of the neck. Klippel–Feil syndrome is sometimes identified by shortness of the neck, but not all people with this disorder have a visibly shortened neck. Some people with the syndrome have a very low hairline.

In 1919, in his PhD thesis, André Feil suggested another classification of the syndrome encompassing not only deformation of the cervical spine but also deformation of the lumbar and thoracic spine.

Syringomyelia causes a wide variety of neuropathic symptoms due to damage of the spinal cord and the nerves inside. Patients may experience severe chronic pain, abnormal sensations and loss of sensation particularly in the hands. Some patients experience paralysis or paresis temporarily or permanently. A syrinx may also cause disruptions in the parasympathetic and sympathetic nervous systems, leading to abnormal body temperature or sweating, bowel control issues, or other problems. If the syrinx is higher up in the spinal cord or affecting the brainstem as in syringobulbia, vocal cord paralysis, ipsilateral tongue wasting, trigeminal nerve sensory loss, and other signs may occur. Rarely, bladder stones can occur in the onset of weakness in the lower extremities.

Classically, syringomyelia spares the dorsal column/medial lemniscus of the spinal cord, leaving pressure, vibration, touch and proprioception intact in the upper extremities. Neuropathic arthropathy, also known as a Charcot joint, can occur, particularly in the shoulders, in patients with syringomyelia. The loss of sensory fibers to the joint is theorized to lead to damage of the joint over time.

Several terms are used to describe congenital abnormalities. (Some of these are also used to describe noncongenital conditions, and more than one term may apply in an individual condition.)