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Physicians now use magnetic resonance imaging (MRI) to diagnose syringomyelia. The MRI radiographer takes images of body anatomy, such as the brain and spinal cord, in vivid detail. This test will show the syrinx in the spine or any other conditions, such as the presence of a tumor. MRI is safe, painless, and informative and has greatly improved the diagnosis of syringomyelia.
The physician may order additional tests to help confirm the diagnosis. One of these is called electromyography (EMG), which show possible lower motor neuron damage. In addition, computed axial tomography (CT) scans of a patient's head may reveal the presence of tumors and other abnormalities such as hydrocephalus.
Like MRI and CT scans, another test, called a myelogram, uses radiographs and requires a contrast medium to be injected into the subarachnoid space. Since the introduction of MRI this test is rarely necessary to diagnose syringomyelia.
The possible causes are trauma, tumors and congenital defects. It is most usually observed in the part of the spinal cord corresponding to the neck area. Symptoms are due to spinal cord damage and are: pain, decreased sensation of touch, weakness and loss of muscle tissue. The diagnosis is confirmed with a spinal CT, myelogram or MRI of the spinal cord. The cavity may be reduced by surgical decompression.
Furthermore, evidence also suggests that impact injuries to the thorax area highly correlate with the occurrence of a cervical-located syrinx.
For children younger than eight weeks of age (and possibly in utero), a tethered cord may be observed using ultrasonography. Ultrasonography may still be useful through age 5 in limited circumstances.
MRI imaging appears to be the gold standard for diagnosing a tethered cord.
A tethered cord is often diagnosed as a "low conus." The conus medullaris (or lower termination of the spinal cord) normally terminates at or above the L1-2 disk space (where L1 is the first, or topmost lumbar vertebra). After about 3 months of age, a conus below the L1-2 disk space may indicate a tethered cord and termination below L3-4 is unmistakably tethered. "Cord tethering is often assumed when the conus is below the normal L2-3 level.
TCS, however, is a clinical diagnosis that should be based on "neurological and musculoskeletal signs and symptoms. Imaging features are in general obtained to support rather than make the diagnosis." Clinical evaluation may include a simple rectal examination and may also include invasive or non-invasive urological examination. "Bladder dysfunction occurs in ~40% of patients affected by tethered cord syndrome. ... [I]t may be the earliest sign of the syndrome."
The precise causes of syringomyelia are still unknown although blockage to the flow of cerebrospinal fluid has been known to be an important factor since the 1970s. Scientists in the UK and America continue to explore the mechanisms that lead to the formation of syrinxes in the spinal cord. It has been demonstrated a block to the free flow of cerebrospinal fluid is a contributory factor in the pathogenesis of the disease. Duke University in America and Warwick University are conducting research to explore genetic features of syringomyelia.
Surgical techniques are also being refined by the neurosurgical research community. Successful procedures expand the area around the cerebellum and spinal cord, thus improving the flow of cerebrospinal fluid thereby reducing the syrinx.
It is also important to understand the role of birth defects in the development of hindbrain malformations that can lead to syringomyelia as syringomyelia is a feature of intrauterine life and is also associated with spina bifida. Learning when these defects occur during the development of the fetus can help us understand this and similar disorders, and may lead to preventive treatment that can stop the formation of some birth abnormalities. Dietary supplements of folic acid prior to pregnancy have been found to reduce the number of cases of spina bifida and are also implicated in prevention of cleft palate and some cardiac defects.
Diagnostic technology is another area for continued research. MRI has enabled scientists to see conditions in the spine, including syringomyelia before symptoms appear. A new technology, known as dynamic MRI, allows investigators to view spinal fluid flow within the syrinx. CT scans allow physicians to see abnormalities in the brain, and other diagnostic tests have also improved greatly with the availability of new, non-toxic, contrast dyes.
A 69-year-old male with tethered cord that was low lying and associated with Spina Bifida in the form of meningocele that was operated on as an infant, was studied in this research. He presented with worsened neurological deficits due to progressive lumbar stenosis at the L3-L4 level which was associated with the spinal discs degenerating. Extreme lateral inter body fusion (XLIF) was performed to allow for indirect spinal cord decompression and stability which allowed for neurological improvement. The role of the XLIF approach to this treatment was emphasized and compared to other surgical approaches. It was concluded that surgical decompression should be performed as soon as possible to prevent any further neurological damage. Also concluded was that the XLIF approach is safe and fast and is indicative of a good surgical option to obtain spinal cord indirect decompression and lumbar inter body fusion.
Diagnosis is made through a combination of patient history, neurological examination, and medical imaging. Magnetic resonance imaging (MRI) is considered the best imaging modality for Chiari malformation since it visualizes neural tissue such as the cerebellar tonsils and spinal cord as well as bone and other soft tissues. CT and CT myelography are other options and were used prior to the advent of MRI, but they characterize syringomyelia and other neural abnormalities less well.
By convention the cerebellar tonsil position is measured relative to the basion-opisthion line, using sagittal T1 MRI images or sagittal CT images. The selected cutoff distance for abnormal tonsil position is somewhat arbitrary since not everyone will be symptomatic at a certain amount of tonsil displacement, and the probability of symptoms and syrinx increases with greater displacement, however greater than 5 mm is the most frequently cited cutoff number, though some consider 3–5 mm to be "borderline," and symptoms and syrinx may occur above that. One study showed little difference in cerebellar tonsil position between standard recumbent MRI and upright MRI for patients without a history of whiplash injury. Neuroradiological investigation is used to first rule out any intracranial condition that could be responsible for tonsillar herniation. Neuroradiological diagnostics evaluate the severity of crowding of the neural structures within the posterior cranial fossa and their impact on the foramen magnum. Chiari 1.5 is a term used when both brainstem and tonsillar herniation through the foramen magnum are present.
The diagnosis of a Chiari II malformation can be made prenatally through ultrasound.
Adult presentation in diastematomyelia is unusual. With modern imaging techniques, various types of spinal dysraphism are being diagnosed in adults with increasing frequency. The commonest location of the lesion is at first to third lumbar vertebrae. Lumbosacral adult diastematomyelia is even rarer. Bony malformations and dysplasias are generally recognized on plain x-rays. MRI scanning is often the first choice of screening and diagnosis. MRI generally give adequate analysis of the spinal cord deformities although it has some limitations in giving detailed bone anatomy. Combined myelographic and post-myelographic CT scan is the most effective diagnostic tool in demonstrating the detailed bone, intradural and extradural pathological anatomy of the affected and adjacent spinal canal levels and of the bony spur.
Prenatal ultrasound diagnosis of this anomaly is usually possible in the early to mid third-trimester. An extra posterior echogenic focus between the fetal spinal laminae is seen with splaying of the posterior elements, thus allowing for early surgical intervention and have a favorable prognosis. Prenate ultrasound could also detect whether the diastematomyelia is isolated, with the skin intact or association with any serious neural tube defects. Progressive neurological lesions may result from the "tethering cord syndrome" (fixation of the spinal cord) by the diastematomyelia phenomenon or any of the associated disorders such as myelodysplasia, dysraphia of the spinal cord.
In the late 19th century, Austrian pathologist Hans Chiari described seemingly related anomalies of the hindbrain, the so-called Chiari malformations I, II and III. Later, other investigators added a fourth (Chiari IV) malformation. The scale of severity is rated I – IV, with IV being the most severe. Types III and IV are very rare.
Other conditions sometimes associated with Chiari malformation include hydrocephalus, syringomyelia, spinal curvature, tethered spinal cord syndrome, and connective tissue disorders such as Ehlers-Danlos syndrome and Marfan syndrome.
Chiari malformation is the most frequently used term for this set of conditions. The use of the term Arnold–Chiari malformation has fallen somewhat out of favor over time, although it is used to refer to the type II malformation. Current sources use "Chiari malformation" to describe four specific types of the condition, reserving the term "Arnold-Chiari" for type II only. Some sources still use "Arnold-Chiari" for all four types.
Chiari malformation or Arnold–Chiari malformation should not be confused with Budd-Chiari syndrome, a hepatic condition also named for Hans Chiari.
In Pseudo-Chiari Malformation, Leaking of CSF may cause displacement of the cerebellar tonsils and similar symptoms sufficient to be mistaken for a Chiari I malformation.
Surgery
Surgical intervention is warranted in patients who present with new onset neurological signs and symptoms or have a history of progressive neurological manifestations which can be related to this abnormality. The surgical procedure required for the effective treatment of diastematomyelia includes decompression (surgery) of neural elements and removal of bony spur. This may be accomplished with or without resection and repair of the duplicated dural sacs. Resection and repair of the duplicated dural sacs is preferred since the dural abnormality may partly contribute to the "tethering" process responsible for the symptoms of this condition.
Post-myelographic CT scanning provides individualized detailed maps that enable surgical treatment of cervical diastematomyelia, first performed in 1983.
Observation
Asymptomatic patients do not require surgical treatment. These patients should have regular neurological examinations since it is known that the condition can deteriorate. If any progression is identified, then a resection should be performed.
Whole spine MR imaging may be used to evaluate the extent of syrinx formation (fluid filled cavity within the spinal cord) in CM dogs, developing a thermal camera-based screening test for the disorder and a method of measuring the actual syrinx volume from MR images.
Before the introduction of MRI, the diagnosis of CM and SM were commonly confused with that of allergic skin disorders, disk disease, ear infections and epilepsy. After CM was reported in human patients, the initial research was provided for the diagnosis of animals. MRI in animals is safe, however, to ensure that the patient remains motionless, light general anesthesia is required.
According to recent studies, thermography may be a useful tool in the diagnosis of CM and SM. Thermography requires no sedation or clipping of hair for a dog to be imaged by the infrared camera. After the image is captured, computer software is used to assess changes in the temperature and color pattern to detect abnormality.
A doctor will base his or her diagnosis on the symptoms the patient has and the results of tests, including:
- An X-ray
- Magnetic resonance imaging (MRI), which usually provides the most information
- Computed tomography (CT) scan
Scoliosis is defined as a three-dimensional deviation in the axis of a person's spine In the diagnostic sense, it is defined as a spinal curvature of more than 10 degrees to the right or left as the examiner faces the person, i.e. in the coronal plane. Deformity may also exist to the front or back as the examiner looks at the person from the side, i.e. in the sagittal plane.
Scoliosis has been described as a biomechanical deformity, the progression of which depends on asymmetric forces otherwise known as the Heuter-Volkmann law.
People who initially present with scoliosis are examined to determine whether the deformity has an underlying cause. During a physical examination, the following are assessed to exclude the possibility of underlying condition more serious than simple scoliosis.
The person's gait is assessed, and there is an exam for signs of other abnormalities (e.g., spina bifida as evidenced by a dimple, hairy patch, lipoma, or hemangioma). A thorough neurological examination is also performed, the skin for "café au lait" spots, indicative of neurofibromatosis, the feet for cavovarus deformity, abdominal reflexes and muscle tone for spasticity.
When a person can cooperate, he or she is asked to bend forward as far as possible. This is known as the Adams Forward Bend Test and is often performed on school students. If a prominence is noted, then scoliosis is a possibility and an X-ray may be done to confirm the diagnosis.
As an alternative, a scoliometer may be used to diagnose the condition.
When scoliosis is suspected, weight-bearing full-spine AP/coronal (front-back view) and lateral/sagittal (side view) X-rays are usually taken to assess the scoliosis curves and the kyphosis and lordosis, as these can also be affected in individuals with scoliosis. Full-length standing spine X-rays are the standard method for evaluating the severity and progression of the scoliosis, and whether it is congenital or idiopathic in nature. In growing individuals, serial radiographs are obtained at three- to 12-month intervals to follow curve progression, and, in some instances, MRI investigation is warranted to look at the spinal cord.
The standard method for assessing the curvature quantitatively is measuring the Cobb angle, which is the angle between two lines, drawn perpendicular to the upper endplate of the uppermost vertebra involved and the lower endplate of the lowest vertebra involved. For people with two curves, Cobb angles are followed for both curves. In some people, lateral-bending X-rays are obtained to assess the flexibility of the curves or the primary and compensatory curves.
Congenital and idiopathic scoliosis that develops before the age of 10 is referred to as early onset scoliosis (EOS). Scoliosis that develops after 10 is referred to as adolescent idiopathic scoliosis.
Genetic testing for AIS, which became available in 2009 and is still under investigation, attempts to gauge the likelihood of curve progression.
A study measured outcome from surgery of 49 cases of scoliosis and kyphoscoliosis. Of this sample, 36 patients were monitored for a period of 8 years.
- 23% - excellent condition
- 29% - good condition
- 34% - satisfactory
- 14% - bad
Bad refers to cases where the surgery failed to address the disease and the patient either had to undergo a revision surgery or continues to suffer from a poor quality of life as before surgery.
It should be noted that typically post-surgery complications range up to 5% involving all major and minor complications when measured within one year of surgery. However, there may be a progressive decline in patient’s condition after a few years.
In another study that evaluated surgical treatment of kyphoscoliosis and scoliosis due to congenital reasons, 91% of surgeries were found to be successful and met their intended objectives for the two-year follow-up period after surgery. The sample consisted of 23 patients of whom 17 were male and 6 were female, with an average age of 27 years, ranging from 13 to 61 years. The most popular type of surgeries for spinal correction includes pedicle subtraction osteotomy (PSO) and posterior vertebral column resection (pVCR).
Another study which focused on elderly patients found that the rate of complications was much higher for a sample population of 72 cases with mean age of 60.7 years. The rate of complications was as high as 22% in the entire sample. The study points that in the case of elderly patients, surgery should only be considered when there is no other option left; the disease is in progression stage, and the quality of life has degraded to an extent where conservative treatments can no longer help with pain.
While there are many surgical approaches for spinal deformity correction including anterior only, posterior only, anterior-posterior, the techniques that are most popular nowadays include the posterior only VCR or pVCR. One of the studies which analyze pVCR technique also noted the benefit of using a technique called NMEP monitoring in assisting the surgeon avoid any neurological complications while performing a spine surgery.
In conclusion, the decision to undergo a corrective spine surgery is a complex one but sometimes becomes necessary when the quality of life has degraded to such an extent that potential benefits outweigh the risks. No surgery is devoid of risks but by carefully assessing factors such as the skills and experience of the surgical team, previous record or history of outcomes, and the techniques that are used for spine surgery, a patient along with his or her doctor can certainly help in achieving a successful outcome.
As studies are repeatedly pointing out, the success rates for spinal surgeries have improved so much so that the risks rates can now be comparable to other types of surgeries. These success rates also tend to be higher at a younger age when compared to the elderly age.
For the ossificans form of the condition, unenhanced CT may better show the presence and extent of arachnoid ossifications, and is complementary to MRI, as MRI can be less specific and findings can be confused with regions of calcification or hemosiderin.
If there aren't neurological symptoms (such as difficulties moving, loss of sensation, confusion, etc.) and there is no evidence of pressure on the spinal cord, a conservative approach may be taken such as:
- Drugs, such as aspirin, without steroids to relieve inflammation
- Cervical traction, in which the neck is pulled along its length, thus relieving pressure on the spinal cord
- Using a neck collar or cervical-thoracic suit
If there is pressure on the spinal cord or life-threatening symptoms are present, surgery is recommended.
Arachnoiditis is difficult to treat and treatment is generally limited to alleviation of pain and other symptoms. While arachnoiditis may not yet be curable and can be significantly life-altering, management of the condition, including with medication, physical therapy, and if appropriate, psychotherapy, can help patients cope with the difficulties it presents. Surgical intervention generally has a poor outcome and may only provide temporary relief, but some cases of surgical success have been reported. Epidural steroid injections to treat sciatic pain have been linked as a "cause" of the disease by the U.S. Food and Drug Administration as well as in other research, and are therefore discouraged as a treatment for Arachnoiditis as they will most likely worsen the condition. Some patients benefit from motorized assistance devices such as the Segway or standing wheelchairs, although these types of devices may be beyond the reach of those with limited means. Standing endurance and vibration tolerance are considered before considering such devices in any case.
The type of treatment needed for dogs diagnosed with CM/SM depends on the severity of the condition and the age of the dog. Young dogs with clinical signs should be considered for surgical removal to minimize the progression of the disease as the dog ages. Older dogs with little or no clinical signs may be treated medically, rather than surgically. However, severe cases of CM/SM may require surgery regardless of age. The goal of surgery is syrynx decompression through restoration of normal cerebrospinal fluid circulation.
The surgical treatment of CM in dogs is described as "foramen magnum decompression FMD". Despite an approximately 80% success rate with this surgical technique, there is a 25% to 50% relapse, primarily due to excessive scar tissue formation at the decompression site. A cranioplasty may be performed instead, in which a plate, constructed using titanium mesh and bone cement, is fixed to the back of the skull following a standard FMD procedure. The procedure had been effective in humans. The postoperative relapse rate associated with the titanium cranioplasty procedure is less than 7%.
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.
Syringobulbia is a medical condition in which syrinxes, or fluid-filled cavities, affect the brainstem. This defect normally results from congenital abnormality, trauma or tumor growth.
It mostly occurs within the lower brainstem as a slit-like gap. This may affect one or more cranial nerves, resulting in various kinds of facial palsies. Sensory and motor nerve pathways may be affected by interruption or compression of nerves. This disorder is associated with syringomyelia, a syrinx limited to the spinal cord.
Different features of the dysostosis are significant. Radiological imaging helps confirm the diagnosis. During gestation (pregnancy), clavicular size can be calculated using available nomograms. Wormian bones can sometimes be observed in the skull.
Diagnosis of CCD spectrum disorder is established in an individual with typical clinical and radiographic findings and/or by the identification of a heterozygous pathogenic variant in RUNX2 (CBFA1).
There is no cure for this condition. Treatment is supportive and varies depending on how symptoms present and their severity. Some degree of developmental delay is expected in almost all cases of M-CM, so evaluation for early intervention or special education programs is appropriate. Rare cases have been reported with no discernible delay in academic or school abilities.
Physical therapy and orthopedic bracing can help young children with gross motor development. Occupational therapy or speech therapy may also assist with developmental delays. Attention from an orthopedic surgeon may be required for leg length discrepancy due to hemihyperplasia.
Children with hemihyperplasia are thought to have an elevated risk for certain types of cancers. Recently published management guidelines recommend regular abdominal ultrasounds up to age eight to detect Wilms' tumor. AFP testing to detect liver cancer is not recommended as there have been no reported cases of hepatoblastoma in M-CM patients.
Congenital abnormalities in the brain and progressive brain overgrowth can result in a variety of neurological problems that may require intervention. These include hydrocephalus, cerebellar tonsillar herniation (Chiari I), seizures and syringomyelia. These complications are not usually congenital, they develop over time often presenting complications in late infancy or early childhood, though they can become problems even later. Baseline brain and spinal cord MRI imaging with repeat scans at regular intervals is often prescribed to monitor the changes that result from progressive brain overgrowth.
Assessment of cardiac health with echocardiogram and EKG may be prescribed and arrhythmias or abnormalities may require surgical treatment.
Dissociated sensory loss is a pattern of neurological damage caused by a lesion to a single tract in the spinal cord which involves "selective" loss of fine touch and proprioception "without" loss of pain and temperature, or vice versa.
Understanding the mechanisms behind these selective lesions requires a brief discussion of the anatomy involved.
Loss of pain and temperature are due to damage to the lateral spinothalamic tracts, which cross the central part of the cord close to the level where they enter it and travel up the spinal column on the opposite side to the one they innervate (i.e. they "ascend contralaterally"). Note that a lesion of the lateral spinothalamic tract at a given level will not result in sensory loss for the dermatome of the same level; this is due to the fibers of the tract of Lissauer which transmit the neuron one or two levels above the affected segment (thus bypassing the segmental lesion on the contralateral side).
Loss of fine touch and proprioception are due to damage to the dorsal columns, which do not cross the cord until the brainstem, and so travel up the column on the same side to the one they innervate (i.e. they "ascend ipsilaterally").
This means that a lesion of the dorsal columns will cause loss of touch and proprioception below the lesion and on the same side as it, while a lesion of the spinothalamic tracts will cause loss of pain and temperature below the lesion and on the opposite side to it.
Dissociated sensory loss always suggests a focal lesion within the spinal cord or brainstem.
The location of cord lesions affects presentation—for instance, a central lesion (such as that of syringomyelia) will knock out second order neurons of the spinothalamic tract as they cross the centre of the cord, and will cause loss of pain and temperature without loss of fine touch or proprioception.
Other causes of dissociated sensory loss include:
- Diabetes mellitus
- Syringomyelia
- Brown-Séquard syndrome
- Lateral medullary syndrome aka Wallenberg's syndrome
- Anterior spinal artery thrombosis
- Tangier disease
- Subacute combined degeneration
- Multiple sclerosis
- Tabes dorsalis
- Friedreich's ataxia (or other spinocerebellar degeneration)
Soft tissue constriction on the medial aspect of the fifth toe is the most frequently presented radiological sign in the early stages. Distal swelling of the toe is considered to be a feature of the disease. In grade III lesions osteolysis is seen in the region of the proximal interphalangeal joint with a characteristic tapering effect. Dispersal of the head of the proximal phalanx is frequently seen. Finally, after autoamputation, the base of the proximal phalanx remains. Radiological examination allows early diagnosis and staging of ainhum. Early diagnosis is crucial to prevent amputation.
Doppler shows decreased blood flow in posterior tibial artery.
Ainhum is an acquired and progressive condition, and thus differs from congenital annular constrictions. Ainhum has been much confused with similar constrictions caused by other diseases such as leprosy, diabetic gangrene, syringomyelia, scleroderma or Vohwinkel syndrome. In this case, it is called pseudo-ainhum, treatable with minor surgery or intralesional corticosteroids, as with ainhum. It has even been seen in psoriasis or it is acquired by the wrapping toes, penis or nipple with hairs, threads or fibers. Oral retinoids, such as tretinoin, and antifibrotic agents like tranilast have been tested for pseudo-ainhum. Impending amputation in Vohwinkel syndrome can sometimes be aborted by therapy with oral etretinate. It is rarely seen in the United States but often discussed in the international medical literature.
The importance of correctly recognizing progressive muscular atrophy as opposed to ALS is important for several reasons.
- 1) the prognosis is a little better. A recent study found the 5-year survival rate in PMA to be 33% (vs 20% in ALS) and the 10-year survival rate to be 12% (vs 6% in ALS).
- 2) Patients with PMA do not suffer from the cognitive change identified in certain groups of patients with MND.
- 3) Because PMA patients do not have UMN signs, they usually do not meet the "World Federation of Neurology El Escorial Research Criteria" for “Definite” or “Probable” ALS and so are ineligible to participate in the majority of clinical research trials such as drugs trials or brain scans.
- 4) Because of its rarity (even compared to ALS) and confusion about the condition, some insurance policies or local healthcare policies may not recognize PMA as being the life-changing illness that it is. In cases where being classified as being PMA rather than ALS is likely to restrict access to services, it may be preferable to be diagnosed as "slowly progressive ALS" or "lower motor neuron predominant" ALS.
An initial diagnosis of PMA could turn out to be slowly progressive ALS many years later, sometimes even decades after the initial diagnosis. The occurrence of upper motor neurone symptoms such as brisk reflexes, spasticity, or a Babinski sign would indicate a progression to ALS; the correct diagnosis is also occasionally made on autopsy.