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.

Brain herniation frequently presents with abnormal posturing a characteristic positioning of the limbs indicative of severe brain damage. These patients have a lowered level of consciousness, with Glasgow Coma Scores of three to five. One or both pupils may be dilated and fail to constrict in response to light. Vomiting can also occur due to compression of the vomiting center in the medulla oblongata.

Symptoms of a herniated disc can vary depending on the location of the herniation and the types of soft tissue that become involved. They can range from little or no pain if the disc is the only tissue injured, to severe and unrelenting neck or lower back pain that will radiate into the regions served by affected nerve roots that are irritated or impinged by the herniated material. Often, herniated discs are not diagnosed immediately, as the patients come with undefined pains in the thighs, knees, or feet. Other symptoms may include sensory changes such as numbness, tingling, paresthesia, and motor changes such as muscular weakness, paralysis and affection of reflexes. If the herniated disc is in the lumbar region the patient may also experience sciatica due to irritation of one of the nerve roots of the sciatic nerve. Unlike a pulsating pain or pain that comes and goes, which can be caused by muscle spasm, pain from a herniated disc is usually continuous or at least is continuous in a specific position of the body. It is possible to have a herniated disc without any pain or noticeable symptoms, depending on its location. If the extruded nucleus pulposus material doesn't press on soft tissues or nerves, it may not cause any symptoms. A small-sample study examining the cervical spine in symptom-free volunteers has found focal disc protrusions in 50% of participants, which suggests that a considerable part of the population can have focal herniated discs in their cervical region that do not cause noticeable symptoms.

A prolapsed disc in the lumbar spine can cause radiating nerve pain. This type of pain is usually felt in the lower extremities or groin area. Radiating nerve pain caused by a prolapsed disc can also cause bowel and bladder incontinence.

Typically, symptoms are experienced only on one side of the body. If the prolapse is very large and presses on the nerves within the spinal column or the cauda equina, both sides of the body may be affected, often with serious consequences. Compression of the cauda equina can cause permanent nerve damage or paralysis. The nerve damage can result in loss of bowel and bladder control as well as sexual dysfunction. This disorder is called cauda equina syndrome.

Other complications include chronic pain.

Most people who develop SCSFLS feel the sudden onset of a severe and acute headache. It is a headache usually made worse by standing, typically becoming prominent throughout the day, with the pain becoming less severe when lying down. Orthostatic headaches can become chronic and disabling to the point of incapacitation. Some patients with SCSFLS will develop headaches that begin in the afternoon. This is known as "second-half-of-the-day headache". This may be an initial presentation of a spontaneous CSF leak or appear after treatment such as an epidural patch, and likely indicates a slow CSF leak.

Apart from headache, about 50% of patients experience neck pain or stiffness, nausea, and vomiting. Other symptoms include dizziness and vertigo, facial numbness or weakness, unusually blurry or double vision, neuralgia, fatigue, or a metallic taste in the mouth. Leaking CSF can sometimes be felt or observed as a discharge from the nose or ear.

Lack of CSF pressure and volume can allow the brain to sag and descend through the foramen magnum (large opening) of the occipital bone, at the base of the skull. The lower portion of the brain is believed to stretch or impact one or more cranial nerve complexes, thereby causing a variety of sensory symptoms. Nerves that can be affected and their related symptoms are detailed in the table at right.

SCSFLS is classified into two main types, cranial leaks and spinal leaks. The vast majority of leaks are spinal. Cranial leaks occur in the head. In some of these cases, CSF can be seen dripping out of the nose, or ear. Spinal leaks occur when one or more holes form in the dura along the spinal cord. Both cranial and spinal spontaneous CSF leaks cause neurological symptoms as well as spontaneous intracranial hypotension, diminished volume and pressure of the cranium. While referred to as "intracranial hypotension", the intracranial pressure may be normal, with the underlying issue instead being low-volume CSF. For this reason SCSFLS is referred to as "CSF hypovolemia" as opposed to "CSF hypotension".

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.

In "central herniation", the diencephalon and parts of the temporal lobes of both of the cerebral hemispheres are squeezed through a notch in the tentorium cerebelli. Transtentorial herniation can occur when the brain moves either up or down across the tentorium, called ascending and descending transtentorial herniation respectively; however descending herniation is much more common. Downward herniation can stretch branches of the basilar artery (pontine arteries), causing them to tear and bleed, known as a Duret hemorrhage. The result is usually fatal. Other symptoms of this type of herniation include small, dilated, fixed pupils with paralysis of upward eye movement giving the characteristic appearance of "sunset eyes". Also found in these patients, often as a terminal complication is the development of diabetes insipidus due to the compression of the pituitary stalk. Radiographically, downward herniation is characterized by obliteration of the suprasellar cistern from temporal lobe herniation into the tentorial hiatus with associated compression on the cerebral peduncles. Upwards herniation, on the other hand, can be radiographically characterized by obliteration of the quadrigeminal cistern. Intracranial hypotension syndrome has been known to mimic downwards transtentorial herniation.

Spinal disc herniation, also known as a slipped disc, is a medical condition affecting the spine in which a tear in the outer, fibrous ring of an intervertebral disc allows the soft, central portion to bulge out beyond the damaged outer rings. Disc herniation is usually due to age-related degeneration of the outer ring, known as the anulus fibrosus, although trauma, lifting injuries, or straining have been implicated as well. Tears are almost always postero-lateral (on the back of the sides) owing to the presence of the posterior longitudinal ligament in the spinal canal. This tear in the disc ring may result in the release of chemicals causing inflammation, which may directly cause severe pain even in the absence of nerve root compression.

Disc herniations are normally a further development of a previously existing disc protrusion, a condition in which the outermost layers of the anulus fibrosus are still intact, but can bulge when the disc is under pressure. In contrast to a herniation, none of the central portion escapes beyond the outer layers. Most minor herniations heal within several weeks. Anti-inflammatory treatments for pain associated with disc herniation, protrusion, bulge, or disc tear are generally effective. Severe herniations may not heal of their own accord and may require surgery. The condition is widely referred to as a "slipped disc", but this term is not medically accurate as the spinal discs are firmly attached between the vertebrae and cannot "slip" out of place.

Lumbar spinal stenosis is classified as a narrowing of the spinal canal in the lumbar region of the vertebrae. This may lead to compression of the nerve root of the spinal cord and result in pain of the lower back and lower extremities. Other symptoms include impaired walking and a slightly stooped posture due to loss of disc height and bulging of the disc. Lumbar spinal stenosis is very prevalent with 9.3% of the general population producing symptoms and the number is continuing to rise in patients older than 60. It's generally an indication for spinal surgery in patients older than 65 years of age.

Meningohydroencephalocoele (AmE: meningohydroencephalocele) is a form of meningocele (AmE) - a developmental abnormality of the central nervous system.

Like meningocoele, meningohydroencephalocoele is caused by defects in bone ossification; in particular, the intramembranous ossification related to the closure of infantile fontanelles. It refers to the protrusion of the meninges between the un-fused bones, to lie subcutaneously.

- Meningocoele - refers to herniation of meninges.

- Meningoencephalocoele refers to the condition if brain tissue is included with the meninges in the herniation.

- Meningohydroencephalocoele refers to the condition including meninges, brain tissue and part of the ventricular system in the herniation.

Encephalocoele defects occur in approximately 1 in 2000 live births.

Including the symptoms listed above, clinical presentations of "wobblers" can also include neck pain and stiffness, difficulty tracking up or gait abnormalities, decreased performance, intermittent or swapping lameness particularly in diagonal pairs, forelimb lameness, abnormal head and neck posture, defensiveness or change in behavior, and abnormal sweat patterns.

Pain, loss of muscle strength and loss of touch sensation may occur if this herniation causes the compression of the most proximal part of the nerve closely neighbouring the intervertebral disc material. Pain is in the distribution of the nerve compressed, usually down the back of the leg, side of the calf and inside of the foot (sciatica). Most commonly, the nerve root between the fourth and fifth lumbar vertebrae or between the fifth lumbar vertebra and first sacral segment are impinged.

In symptomatic cases the diagnosis should be confirmed by an MRI scan. However, in cases with slight symptoms, a faster and cheaper CT scan (although it is inferior to MRI scan) may be recommended. While a CT scan can show the bony structures in more detail, an MRI scan can better portray soft tissue.

Wobbler disease is a catchall term referring to several possible malformations of the cervical vertebrae that cause an unsteady (wobbly) gait and weakness in dogs and horses. A number of different conditions of the cervical (neck) spinal column cause similar clinical signs. These conditions may include malformation of the vertebrae, intervertebral disc protrusion, and disease of the interspinal ligaments, ligamenta flava, and articular facets of the vertebrae. Wobbler disease is also known as cervical vertebral instability, cervical spondylomyelopathy (CSM), and cervical vertebral malformation (CVM). In dogs, the disease is most common in large breeds, especially Great Danes and Doberman Pinschers. In horses, it is not linked to a particular breed, though it is most often seen in tall, race-bred horses of Thoroughbred or Standardbred ancestry. It is most likely inherited to at least some extent in dogs and horses.

Severe back pain, saddle anesthesia, incontinence and sexual dysfunction are considered "red flags", i.e. features which require urgent investigation.

Lumbar disc disease is the drying out of the spongy interior matrix of an intervertebral disc in the spine. Many physicians and patients use the term lumbar disc disease to encompass several different causes of back pain or sciatica. In this article, the term is used to describe a lumbar herniated disc. It is thought that lumbar disc disease causes about one-third of all back pain.

Grynfeltt-Lesshaft hernia is a herniation of abdominal contents through the back, specifically through the superior lumbar triangle, which is defined by the quadratus lumborum muscle, twelfth rib, and internal oblique muscle.

Breath sounds on the side of the rupture may be diminished, respiratory distress may be present, and the chest or abdomen may be painful. Orthopnea, dyspnea which occurs when lying flat, may also occur, and coughing is another sign. In people with herniation of abdominal organs, signs of intestinal blockage or sepsis in the abdomen may be present. Bowel sounds may be heard in the chest, and shoulder or epigastric pain may be present. When the injury is not noticed right away, the main symptoms are those that indicate bowel obstruction.

Cauda equina syndrome (CES) is symptoms due to damage to the bundle of nerves below the end of the spinal cord known as the cauda equina. Symptoms include, low back pain, pain that radiates down the leg, numbness around the anus, and loss of bowel or bladder control. Onset may be rapid or gradual.

The cause is usually a disc herniation in the lower region of the back. Other causes include spinal stenosis, cancer, trauma, epidural abscess, and epidural hematoma. Diagnosis is often by medical imaging such as MRI or CT scan.

Treatment is generally by urgent surgery in the form of a laminectomy. Some people are left with ongoing bladder problems, sexual dysfunction, or numbness. A poor outcome occurs in about 20% of people despite treatment. About 1 in 70,000 people is affected a year. It was first described in 1934.

Diaphragmatic rupture (also called diaphragmatic injury or tear) is a tear of the diaphragm, the muscle across the bottom of the ribcage that plays a crucial role in respiration. Most commonly, acquired diaphragmatic tears result from physical trauma. Diaphragmatic rupture can result from blunt or penetrating trauma and occurs in about 5% of cases of severe blunt trauma to the trunk.

Diagnostic techniques include X-ray, computed tomography, and surgical techniques such as laparotomy. Diagnosis is often difficult because signs may not show up on X-ray, or signs that do show up appear similar to other conditions. Signs and symptoms included chest and abdominal pain, difficulty breathing, and decreased lung sounds. When a tear is discovered, surgery is needed to repair it.

Injuries to the diaphragm are usually accompanied by other injuries, and they indicate that more severe injury may have occurred. The outcome often depends more on associated injuries than on the diaphragmatic injury itself. Since the pressure is higher in the abdominal cavity than the chest cavity, rupture of the diaphragm is almost always associated with herniation of abdominal organs into the chest cavity, which is called a traumatic diaphragmatic hernia. This herniation can interfere with breathing, and blood supply can be cut off to organs that herniate through the diaphragm, damaging them.

Cerebellar stroke syndrome is a condition in which the circulation to the cerebellum is impaired due to a lesion of the superior cerebellar artery, anterior inferior cerebellar artery or the posterior inferior cerebellar artery.

Cardinal signs include vertigo, headache, vomiting, and ataxia.

Cerebellar strokes account for only 2-3% of the 600 000 strokes that occur each year in the United States. They are far less common than strokes which occur in the cerebral hemispheres. In recent years mortality rates have decreased due to advancements in health care which include earlier diagnosis through MRI and CT scanning. Advancements have also been made which allow earlier management for common complications of cerebellar stroke such as brainstem compression and hydrocephalus.

Research is still needed in the area of cerebellar stroke management; however, it has been proposed that several factors may lead to poor outcomes in individuals who suffer from cerebellar stroke. These factors include:

1. Declining levels of consciousness

2. New signs of brainstem involvement

3. Progressing Hydrocephalus

4. Stroke to the midline of the cerebellum (a.k.a. the vermis)

Grynfeltt described a hernia through the superior lumbar triangle in 1866 (Grynfeltt, 1866). In 1870, Lesshaft independently reported a similar case (Lesshaft, 1870).

The key features of this syndrome are an enlargement of the fourth ventricle; complete absence of the cerebellar vermis, the posterior midline area of cerebellar cortex responsible for coordination of the axial musculature; and cyst formation near the internal base of the skull. An increase in the size of the fluid spaces surrounding the brain as well as an increase in pressure may also be present. The syndrome can appear dramatically or develop unnoticed.

Symptoms, which often occur in early infancy, include slower motor development and progressive enlargement of the skull. In older children, symptoms of increased intracranial pressure such as irritability, vomiting, and convulsions and signs of cerebellar dysfunction such as unsteadiness and lack of muscle coordination or jerky movements of the eyes may occur. Other symptoms include increased head circumference, bulging at the back of the skull, problems with the nerves that control the eyes, face and neck, and abnormal breathing patterns.

Dandy–Walker syndrome is frequently associated with disorders of other areas of the central nervous system including absence of the corpus callosum, the bundle of axons connecting the two cerebral hemispheres, and malformations of the heart, face, limbs, fingers and toes.

The Dandy–Walker complex is a genetically sporadic disorder that occurs one in every 30,000 live births. Prenatal diagnosis and prognosis of outcomes associated with Dandy–Walker can be difficult. Prenatal diagnosis is possible with ultrasound. Because the syndrome is associated with an increased risk for fetal karyotype abnormalities, amniocentesis can be offered after prenatal diagnosis. There is a relative contraindication of taking Warfarin during pregnancy, as it is associated with an increased risk of Dandy–Walker syndrome if taken during the first trimester.

The DWS malformation is the most severe presentation of the syndrome. The posterior fossa is enlarged and the tentorium is in high position. There is complete agenesis of the cerebellar vermis. There is also cystic dilation of the fourth ventricle, which fills the posterior fossa. This often involves hydrocephalus and complications due to associated genetic conditions, such as Spina Bifida.

The symptoms of a cerebral contusion (bruising on the brain) depend on the severity of the injury, ranging from minor to severe. Individuals may experience a headache; confusion; sleepiness; dizziness; loss of consciousness; nausea and vomiting; seizures; and difficulty with coordination and movement. They may also have difficulty with memory, vision, speech, hearing, managing emotions, and thinking. Signs depend on the contusion's location in the brain.