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Wobblers is definitively diagnosed by x-ray, nuclear scintography or bone scan. X-rays will show channel widening or filling the easiest and are often most cost effective to horse owners. X-rays will also show any structural anomaly, arthritis, facet remodeling, or bone spurs present. Preliminary diagnosis can be made by ultrasound but x-rays are needed to measure the true depth of facet involvement. For extent of damage to associated structures, veterinarians may opt to have the horse undergo a bone scan or nuclear scintography.
Checking the eyes for signs of papilledema should be carried out whenever there is a clinical suspicion of raised intracranial pressure, and is recommended in newly onset headaches. This may be done by ophthalmoscopy or fundus photography, and possibly slit lamp examination.
Because there are various causes for back injuries, prevention must be comprehensive. Back injuries are predominant in manual labor so the majority low back pain prevention methods have been applied primarily toward biomechanics Prevention must come from multiple sources such as education, proper body mechanics, and physical fitness.
Initial treatment in lumbar disc disease is one or two days of bedrest (although growing number of studies shows that it makes little difference) and pain relieving medications. In cases with ongoing pain despite conservative treatments, a surgical operation that will remove the compressing disc material, a microdiscectomy or discectomy may be recommended to treat a lumbar disc herniation.
The development of accurate and reliable non-invasive ICP measurement methods for VIIP has the potential to benefit many patients on earth who need screening and/or diagnostic ICP measurements, including those with hydrocephalus, intracranial hypertension, intracranial hypotension, and patients with cerebrospinal fluid shunts. Current ICP measurement techniques are invasive and require either a lumbar puncture, insertion of a temporary spinal catheter, insertion of a cranial ICP monitor, or insertion of a needle into a shunt reservoir.
Optic pits should be diagnosed by an eye care professional who can perform a thorough exam of the back of the eye using an ophthalmoscope.
More recently, the development of a special technology called optical coherence tomography (OCT) has allowed better visualization of the retinal layers. It has been used to demonstrate a marked reduction in the thickness of the retinal nerve fiber layer in the quadrant corresponding to the optic pit. This is not yet in standard use for diagnosis of an optic pit, but may be helpful in supporting a diagnosis.
Diagnosis of a cerebrospinal fluid leak is performed through a combination of measurement of the CSF pressure and a computed tomography myelogram (CTM) scan of the spinal column for fluid leaks. The opening fluid pressure in the spinal canal is obtained by performing a lumbar puncture, also known as a spinal tap. Once the pressure is measured, a radiocontrast agent is injected into the spinal fluid. The contrast then diffuses out through the dura sac before leaking through dural holes. This allows for a CTM with fluoroscopy to locate and image any sites of dura rupture via contrast seen outside the dura sac in the imagery.
Visual fields associated with chiasmal syndrome usually leads to an MRI. Contrast can delineate arterial aneurysms and will enhance most intrinsic chiasmal lesions. If a mass is confirmed on MRI, an endocrine panel can help determine if a pituitary adenoma is involved.
In patients with functional adenomas diagnosed by other means, visual field tests are a good screen to test for chiasmal involvement. Visual fields tests will delinate chiasmal syndromes because the missing fields will not cross the midline. Junctional scotomas classically show ipsilateral optic disc neuropathy with contralateral superotemporal defects. Bitemporal hemianopia with or without central scotoma is present if the lesions have affected the body of the chiasm. A posterior chiasm lesion should only produce defects on the temporal sides of the central visual field.
The straight leg raise may be positive, as this finding has low specificity; however, it has high sensitivity. Thus the finding of a negative SLR sign is important in helping to "rule out" the possibility of a lower lumbar disc herniation. A variation is to lift the leg while the patient is sitting. However, this reduces the sensitivity of the test.
Diagnosis of degenerative disc disease will usually consist of an analysis of a patient's individual medical history, a physical exam designed to reveal muscle weakness, tenderness or poor range of motion, and an MRI scan to confirm the diagnosis and rule out other causes.
Magnetic resonance imaging is less effective than CT at directly imaging sites of CSF leak. MRI studies may show pachymeningeal enhancement (when the dura mater looks thick and inflamed), sagging of the brain, pituitary enlargement, subdural hygromas, engorgement of cerebral venous sinuses, and other abnormalities. For 20% of patients, MRIs present as completely normal. There is disagreement over whether MRI should be the study of choice. MRIs performed with the patient seated upright (vs. laying supine) are not better for diagnosing CSF leaks, but are more than twice as effective at diagnosing cerebellar tonsillar ectopia, also known as Chiari malformation. Cerebellar tonsillar ectopia shares many of the same symptoms as CSF leak, but originates either congenitally or from trauma, including whiplash strain to the dura.
An alternate method of locating the site of a CSF leak is to use heavily T2-weighted MR myelography. This has been effective in identifying the sites of a CSF leak without the need for a CT scan, lumbar puncture, and contrast and at locating fluid collections such as CSF pooling. Another highly successful method of locating a CSF leak is intrathecal contrast and MR Myelography.
The diagnosis may be suspected on the basis of the history and examination. To confirm the diagnosis, as well as excluding alternative causes, several investigations are required; more investigations may be performed if the history is not typical or the patient is more likely to have an alternative problem: children, men, the elderly, or women who are not overweight.
Historically, papilledema was a potential contraindication to lumbar puncture, as it indicates a risk for tentorial herniation and subsequent death via cerebral herniation, however newer imaging techniques have been more useful at determining when and when not to conduct a lumbar puncture. Imaging by CT or MRI is usually performed to elicit whether there is a structural cause i.e., tumor. An MRA and MRV may also be ordered to rule out the possibility of stenosis or thrombosis of the arterial or venous systems.
The treatment depends largely on the underlying cause. However, the root cause of papilledema is the increased intracranial pressure (ICP). This is a dangerous sign, indicative of a brain tumor, CNS inflammation or idiopathic intracranial hypertension (IIH) that may become manifest in the near future.
Thus, a biopsy is routinely performed prior to the treatment in the initial stages of papilledema to detect whether a brain tumor is present. If detected, laser treatment, radiation and surgeries can be used to treat the tumor.
To decrease ICP, medications can be administered by increasing the absorption of Cerebrospinal fluid (CSF), or decreasing its production. Such medicines include diuretics like acetazolamide and furosemide. These diuretics, along with surgical interventions, can also treat IIH. In IIH, weight loss (even a loss of 10-15%) can lead to normalization of ICP.
Meanwhile, steroids can reduce inflammation (if this is a contributing factor to increased ICP), and may help to prevent vision loss. However, steroids have also been known to cause increased ICP, especially with a change in dosage. However, if a severe inflammatory condition exists, such as multiple sclerosis, steroids with anti-inflammatory effects such as Methylprednisolone and prednisone can help.
Other treatments include repeated lumbar punctures to remove excess spinal fluid in the cranium. The removal of potentially causative medicines including tetracyclines and vitamin A analogues may help decrease ICP; however, this is only necessary if the medication is truly felt to contribute to the ICP increase.
Neuroimaging, usually with computed tomography (CT/CAT) or magnetic resonance imaging (MRI), is used to exclude any mass lesions. In IIH these scans typically appear to be normal, although small or slit-like ventricles, dilatation and buckling of the optic nerve sheaths and "empty sella sign" (flattening of the pituitary gland due to increased pressure) and enlargement of Meckel's caves may be seen.
An MR venogram is also performed in most cases to exclude the possibility of venous sinus stenosis/obstruction or cerebral venous sinus thrombosis. A contrast-enhanced MRV (ATECO) scan has a high detection rate for abnormal transverse sinus stenoses. These stenoses can be more adequately identified and assessed with catheter cerebral venography and manometry. Buckling of the bilateral optic nerves with increased perineural fluid is also often noted on MRI imaging.
Lumbar puncture is performed to measure the opening pressure, as well as to obtain cerebrospinal fluid (CSF) to exclude alternative diagnoses. If the opening pressure is increased, CSF may be removed for transient relief (see below). The CSF is examined for abnormal cells, infections, antibody levels, the glucose level, and protein levels. By definition, all of these are within their normal limits in IIH. Occasionally, the CSF pressure measurement may be normal despite very suggestive symptoms. This may be attributable to the fact that CSF pressure may fluctuate over the course of the normal day. If the suspicion of problems remains high, it may be necessary to perform more long-term monitoring of the ICP by a pressure catheter.
Patients with optic disc drusen should be monitored periodically for ophthalmoscopy, Snellen acuity, contrast sensitivity, color vision, intraocular pressure and threshold visual fields. For those with visual field defects optical coherence tomography has been recommended for follow up of nerve fiber layer thickness. Associated conditions such as angioid streaks and retinitis pigmentosa should be screened for. Both the severity of optic disc drusen and the degree of intraocular pressure elevation have been associated with visual field loss. There is no widely accepted treatment for ODD, although some clinicians will prescribe eye drops designed to decrease the intra-ocular pressure and theoretically relieve mechanical stress on fibers of the optic disc. Rarely choroidal neovascular membranes may develop adjacent to the optic disc threatening bleeding and retinal scarring. Laser treatment or photodynamic therapy or other evolving therapies may prevent this complication.
Risk factors and underlying mechanisms based on anatomy, physiology, genetics and epigenetics need to be researched further.
The following actions have been recommended to assist in the research of vision impairment and increased intracranial pressure associated with long-duration space flight:
Clinical examination will show an abnormal optic disc, either swollen or atrophic. Optociliary shunt vessels may be seen; the combination of these with progressive visual loss and optic disc atrophy is known as the Hoyt-Spencer triad. Visual acuity is usually but not always reduced.
When ONSM is suspected, MRI of the brain or orbits should be performed. This will usually show characteristic findings and confirm the diagnosis.
The United States Preventive Services Task Force as of 2013 states there is insufficient evidence to recommend for or against screening for glaucoma. Therefore, there is no national screening program in the US. Screening, however, is recommended starting at age 40 by the American Academy of Ophthalmology.
There is a glaucoma screening program in the UK. Those at risk are advised to have a dilated eye examination at least once a year.
The first noticeable signs of the syndrome usually do not appear until after the first twelve months of the child’s life. The child usually has severe balance issues as he or she learns to sit or walk, often leaning or tilting the head toward the good eye to correct the brain’s skewed perception of the world. Often the child will fall in the same direction while walking or run into objects that are placed on his or her blind side. Additionally, family members may notice a white reflex in the pupil of an affected child instead of the normal red reflex when taking photographs. The presence of this phenomenon is dependent on the degree of the coloboma, with larger colobomas more likely to manifest this particular phenomenon.
This anomaly must be confirmed through pupillary dilation and examination of the optic disc, as the symptoms alone do not constitute a diagnosis.
People with optic nerve colobomas live relatively normal lives. Although non-prescription glasses should be worn for eye protection, this syndrome does not usually prevent the individual from living a normal life, driving cars, playing sports, reading, etc. Certain activities, however, may be more difficult for patients with optic nerve colobomas due to a compromised view of the world. Like most other eye conditions, a diagnosis of optic nerve coloboma precludes a person from certain occupations.
ONSM does not improve without treatment. In many cases, there is gradual progression until vision is lost in the affected eye. However, this takes at least several months to occur, and a minority of patients remain stable for a number of years.
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.
In most patients, optic disc drusen are an incidental finding. It is important to differentiate them from other conditions that present with optic disc elevation, especially papilledema, which could imply raised intracranial pressure or tumors. True papilledema may present with exudates or cotton-wool spots, unlike ODD. The optic disc margins are characteristically irregular in ODD but not blurred as there is no swelling of the retinal nerve fibers. Spontaneous venous pulsations are present in about 80 percent of patients with ODD, but absent in cases of true disc edema. Other causes of disc elevation clinicians must exclude may be: hyaloid traction, epipapillary glial tissue, myelinated nerve fibres, scleral infiltration, vitreopapillary traction and high hyperopia. Disorders associated with disc elevation include: Alagille syndrome, Down syndrome, Kenny-Caffey syndrome, Leber Hereditary Optic Neuropathy and linear nevus sebaceous syndrome.
A thorough history is essential and should cover family history, diet; drug/toxin exposure social history, including tobacco and alcohol use; and occupational background, with details on whether similar cases exist among coworkers. Treatment of any chronic disease such as pernicious anemia should always be elucidated.
In most cases of nutritional/toxic optic neuropathy, the diagnosis may be obtained via detailed medical history and eye examination. Additionally, supplementary neurological imaging studies, such as MRI or enhanced CT, may be performed if the cause remains unclear.
When the details of the examination and history indicate a familial history of similar ocular or systemic disease, whether or not there is evidence of toxic or nutritional causes for disease, certain genetic tests may be required. Because there are several congenital causes of mitochondrial dysfunction, the patients history, examination, and radiological studies must be examined in order to determine the specific genetic tests required. For example, 90% of cases of Leber’s Hereditary Optic Neuropathy (LHON) are associated with three common mtDNA point mutations (m.3460G>A/MT-ND1, m.11778G>A/MT-ND4, m.14484T>C/MT-ND6) while a wider range of mtDNA mutations (MT-ND1, MT-ND5, MT-ND6; http://www.mitomap.org/) have been associated with overlapping phenotypes of LHON, MELAS, and Leigh syndrome.
Optic pits themselves do not need to be treated. However, patients should follow up with their eye care professional annually or even sooner if the patient notices any visual loss whatsoever. Treatment of PVD or serous retinal detachment will be necessary if either develops in a patient with an optic pit.
Controversies exist around eliminating this disorder from breeding Collies. Some veterinarians advocate only breeding dogs with no evidence of disease, but this would eliminate a large portion of potential breeding stock. Because of this, others recommend only breeding mildly affected dogs, but this would never completely eradicate the condition. Also, mild cases of choroidal hypoplasia may become pigmented and therefore undiagnosable by the age of three to seven months. If puppies are not checked for CEA before this happens, they may be mistaken for normal and bred as such. Checking for CEA by seven weeks of age can eliminate this possibility. Diagnosis is also difficult in dogs with coats of dilute color because lack of pigment in the choroid of these animals can be confused with choroidal hypoplasia. Also, because of the lack of choroidal pigment, mild choroidal hypoplasia is difficult to see, and therefore cases of CEA may be missed.
Until recently, the only way to know if a dog was a carrier was for it to produce an affected puppy. However, a genetic test for CEA became available at the beginning of 2005, developed by the Baker Institute for Animal Health, Cornell University, and administered through OptiGen. The test can determine whether a dog is affected, a carrier, or clear, and is therefore a useful tool in determining a particular dog's suitability for breeding.