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1.
Chiari malformations and syringohydromyelia are an important disease complex in Cavalier King Charles Spaniels. Although abnormalities in caudal fossa morphology are considered major contributors to the development of this disease, limited information exists on the range of morphologies in Cavalier King Charles Spaniels and on the relationship of these to clinically evident disease. Sixty-four Cavalier King Charles Spaniels were studied. Each underwent a neurologic examination and magnetic resonance imaging of the cervical spine and brain. T2-weighted sagittal images were used to determine both the morphologic characteristics and volume of the caudal fossa in each dog. This volume was also analyzed as a percentage of total cranial cavity volume. Each attribute was correlated with neurological grade and presence of syringohydromyelia. Fifteen dogs had neurologic signs, and 59 had morphologic abnormalities of the craniocervical junction. While 27 dogs had syringohydromyelia, 13 of these were clinically normal. Cerebellar herniation and occipital dysplasia were common findings but were not associated with syringohydromyelia. Dorsal compressive lesions were noted at the first and second cervical vertebral junction. Factors associated with the presence of neurologic signs included syringohydromyelia and the ratio of caudal fossa/total cranial cavity volume; dogs with signs had significantly larger syringohydromyelia than asymptomatic dogs. Caudal fossa size was not associated with syringohydromyelia. A positive association was identified between foramen magnum size and length of cerebellar herniation. The prevalence of craniocervical junction abnormalities is high in Cavalier King Charles Spaniels. While several factors are associated with neurologic signs, occipital hypoplasia appears to be the most important factor.  相似文献   

2.
O bjectives : To ascertain whether cavalier King Charles spaniels (CKCSs) have a proportionately smaller caudal fossa compared with other small dogs and with Labradors. To evaluate if cerebellar herniation in CKCS correlates with caudal fossa volume.
M ethods : In this retrospective study, three-dimensional images were created from magnetic resonance imaging brain series of 117 dogs (split into three groups: CKCS, Labradors and small breeds) from which the volumes of the fossae and brain parenchyma were calculated. These volumes were transformed into percentages of total cranial cavity and parenchyma volumes, respectively. The percentages were statistically compared among the groups. The percentage of herniated cerebellum in the CKCS was compared using linear regression with the caudal fossa and parenchyma percentages.
R esults : Cavalier King Charles spaniels had a proportionately smaller caudal fossa compared with Labradors (P=0·002) but not to small breeds (P=0·103). Their caudal fossa parenchyma was proportionately the same volume as Labradors (P=0·976) but greater than small breeds (P=0·005). No relationship was found for the per cent of cerebellum herniated.
C linical S ignificance : The results support mesoderm insufficiency or craniosynostosis as the pathogenesis of Chiari-like malformation (CM) in CKCS. It presents evidence for overcrowding of the caudal fossa due to a mismatch of brain parenchyma and fossa volumes as to why CKCS and not other small dogs are affected.  相似文献   

3.
A five‐year‐old, female, neutered boxer, with neuroanatomical signs consistent with a C1‐C5 myelopathy, was diagnosed with a prosencephalic mass and associated severe cervicothoracic syringohydromyelia. After treatment with corticosteroids and lomustine, neurological examination was normal. Imaging repeated three months later showed significant reduction in both the size of the mass and the syringohydromyelia. To the authors’ knowledge, this is the first reported case of a dog with syringohydromyelia secondary to a rostral brain mass that had clinical signs on presentation solely due to the syrinx, and the first reported case in a dog of partial resolution of syringohydromyelia after treatment solely with chemotherapy.  相似文献   

4.
A 13-year-old, female neutered, domestic shorthair indoor cat was referred to our hospital for treatment of multiple meningiomas. A slight generalized ataxia was seen, proprioception was severely decreased on all four limbs, and menace reaction was bilaterally reduced. Pre- and postoperatively MRI examination were performed. Three supratentorial extra-axial lesions were imaged. The fourth mass was localized infratentorial extra-axial overlying the left cerebellar hemisphere. The caudoventral cerebellum had herniated caudally, approximately one cm through the foramen magnum. Cervical syringohydromyelia was found as coincidental finding. Multiple craniotomies, centered over the meningiomas were performed. Postoperative outcome two years after the surgery is excellent. The authors also reviewed the veterinary and human literature about intracranial tumors associated syringohydromyelia. Generally, the treatment of syringohydromyelia should be targeted at the pathological process, which causes the obstruction of the cerebrospinal fluid flow, and leads to syringohydromyelia formation.  相似文献   

5.
Syringohydromyelia secondary to foramen magnum overcrowding is described in seven Cavalier King Charles spaniels. Clinical signs were consistent with a central spinal cord lesion. The most common signs were persistent scratching at the shoulder region with apparent neck, thoracic limb, or ear pain and thoracic limb lower motor neuron deficits. The diagnosis was made by magnetic resonance imaging. The syringohydromyelia is postulated to be a consequence of an occipital bone malformation resulting in a small caudal fossa and cerebellar herniation. Clinical signs improved but did not completely resolve when the dogs received treatment with corticosteroids or nonsteroidal anti-inflammatory drugs.  相似文献   

6.
An 11-year-old male Pekingese was evaluated because of a history of head tilt. Neurologic examination revealed a right-sided head tilt, ataxia, scoliosis, and proprioceptive deficits. Diagnostic testing included magnetic resonance imaging (MRI) of the head and neck. After IV administration of gadopentetate dimeglumine, an extra-axial, highly contrast-enhanced mass in the brainstem, cerebellar herniation, and syringohydromyelia were detected via MRI. The dog was treated with corticosteroids and radiation therapy of the mass for 4 weeks (total dose, 42.5 Gy). Magnetic resonance imaging was repeated 9 weeks and 6 months after radiation therapy; compared with the initial findings, a reduction in the size of the brainstem mass was observed in both MRI scans. The third MRI scan also revealed a normal cerebellar shape, no evidence of herniation, and resolution of syringohydromyelia in the dog at that time. It is recommended that whenever syringohydromyelia is observed via MRI, a primary cause (cranial or caudal to the affected region) should be sought.  相似文献   

7.
Ultrasonographic evaluation of the spine, especially of the spinal cord, has been rarely reported in dogs. The atlanto-occipital junction provides a small acoustic window through which examination of the craniocervical transition can be performed. Normal sonographic findings of this region in 10 normal brachycephalic dogs are presented and compared with sonographic findings from 25 Cavalier King Charles Spaniels with the caudal occipital malformation syndrome. Sonographic findings were compared with magnetic resonance imaging findings to determine the extent of cerebellar herniation and syringohydromyelia. Cerebellar displacement into the foramen magnum was clearly identified sonographically; however, syringohydromyelia was not discernable due to bone overlay.  相似文献   

8.
A 2-year-old, intact female rottweiler was presented for signs of lethargy. A mass was ultrasonographically observed, cranial and lateral to the left kidney. Exploratory laparotomy revealed a mass in the left ovary that was diagnosed histopathologically as an ovarian dysgerminoma. Two weeks after surgery, the dog was readmitted with signs of peripheral vestibular disease that progressed to central vestibular disease. Magnetic resonance imaging of the brain revealed the presence of a mass in the caudal fossa. The histopathological diagnosis of the mass was metastases from the ovarian dysgerminoma.  相似文献   

9.
Computed tomography (CT) was used to investigate brain tumors in the caudal fossa of three dogs. Changes detected by CT included compression or distortion of cerebrospinal fluid spaces within the caudal fossa, and changes in parenchymal density before and after intravenous injection of a nondiffusible, iodinated contrast medium. CT provided information regarding tumor size, location, character, and relationships with normal caudal fossa structures. It was concluded that CT offered advantages over technics currently in use for diagnosis and assessment of caudal fossa lesions in the dog.  相似文献   

10.
Chiari-like malformation (CM) is almost omnipresent in the Cavalier King Charles spaniels (CKCS), often leading to syringomyelia (SM). Morphometric studies have produced variable results concerning relationship between the brain parenchyma within the caudal cranial fossa (CCF) and SM. The present study assesses the effect of head position, one potential confounder. Magnetic resonance images of CKCS with CM were reviewed in extended and flexed head positions. Volumes were calculated from transverse T2-weighted brain images. Mid-sagittal images were used for measurement of cerebellar herniation and CSF space between cerebellum and brainstem. Fourteen CKCS were included into the study, seven dogs with CM and seven with CM/SM. There was no difference between the relative brain parenchyma within the CCF in extended position and flexed position, or the brain parenchyma within the rostral and middle cranial fossae proportion. Cerebellar herniation and CSF space between cerebellum and brainstem were significantly increased in the flexed position. Cerebellar herniation and CSF space differed significantly between CM and CM/SM in a flexed head position. Volumetric measurements did not vary with head position. Cerebellar herniation and CSF space between the cerebellum and the brainstem were larger in a flexed head position.  相似文献   

11.
A nine-year-old male, neutered, pug was presented for investigation of progressive ambulatory paraparesis and pelvic limb ataxia of three months' duration. Magnetic resonance imaging was suggestive of caudal thoracic syringohydromyelia with an adjacent intradural arachnoid cyst. The cyst was marsupialised following dorsal laminectomy. Neurological status had improved 10 weeks following surgery when repeat magnetic resonance imaging revealed reduced spinal cord compression both as a result of resolution of the cyst and reduction in size of the syringohydromyelia. At 17 months following surgery, the dog showed further improvements in neurological status, exhibiting mild pelvic limb ataxia and proprioceptive deficits. Improved cerebrospinal fluid flow following surgery may have played a role in the improvement in both conditions. The presence of syringohydromyelia in this context does not preclude a favourable clinical outcome following surgical management.  相似文献   

12.
Intracranial arachnoid diverticula (cysts) are rare accumulations of cerebrospinal fluid (CSF) within the arachnoid membrane. The purpose of this retrospective study was to describe magnetic resonance imaging (MRI) characteristics of fourth ventricle arachnoid diverticula in a group of dogs. The hospital's medical records were searched for dogs with MRI studies of the brain and a diagnosis of fourth ventricle arachnoid diverticulum. Clinical characteristics were recorded from medical records and MRI studies were reinterpreted by a board‐certified veterinary radiologist. Five pediatric dogs fulfilled inclusion criteria. Clinical signs included cervical hyperaesthesia, obtundation, tetraparesis, and/or central vestibular syndrome. In all five dogs, MRI findings were consistent with obstructive hydrocephalus, based on dilation of all ventricles and compression of the cerebellum and brainstem. All five dogs also had cervical syringohydromyelia, with T2‐weighted hyperintensity of the gray matter of the cord adjacent to the syringohydromyelia. A signal void, interpreted as flow disturbance, was observed at the mesencephalic aqueduct in all dogs. Four dogs underwent surgical treatment with occipitalectomy and durotomy. A cystic lesion emerging from the fourth ventricle was detected in all four dogs during surgery and histopathology confirmed the diagnosis of arachnoid diverticula. Three dogs made excellent recovery but deteriorated shortly after surgery and were euthanized. Repeat MRI in two dogs revealed improved hydrocephalus but worsening of the syringohydromyelia. Findings from the current study supported theories that fourth ventricle arachnoid diverticula are secondary to partial obstruction of the central canal or lateral apertures and that arachnoid diverticula are developmental lesions in dogs.  相似文献   

13.
Objectives : The objectives of the study were (1) to report the incidence of Chiari‐like malformation and syringomyelia in a normal French cavalier King Charles spaniel breeding population; (2) to precise the standard computed tomography dimensions of the caudal fossa and (3) to investigate the use of ultrasonography in diagnosis of this syndrome. Methods : Clinically normal adult cavalier King Charles spaniel underwent ultrasonographic examination of the spinal cord and caudal fossa. Computed tomography was used to measure the caudal fossa and magnetic resonance imaging allowed syringomyelia and cerebellar herniation identification. Results : Of the 16 dogs in the study, seven had syringomyelia (43·7 per cent). All dogs had cerebellar herniation, suggesting Chiari‐like malformation and also a tendency to occipital dysplasia. Computed tomography measurements of the caudal fossa are reported. In one dog, a syrinx was identified by ultrasonography. The only difference between dogs with or without syringomyelia was that dogs with Chiari‐like malformation/syringomyelia were statistically older. Clinical Significance : The incidence of Chiari‐like malformation and syringomyelia may be high in an asymptomatic population of cavalier King Charles spaniel . Computed tomography measurements reported in this study should now be compared with those of a symptomatic population to evaluate the hypothesis that dogs with Chiari‐like malformation/syringomyelia syndrome have a smaller caudal fossa. This study did not identify a smaller caudal fossa in an asymptomatic cavalier King Charles spaniel population with syringomyelia. Ultrasonography probably has a low sensitivity for diagnosis of Chiari‐like malformation/syringomyelia.  相似文献   

14.
Magnetic resonance imaging of a 7.5-year-old neutered male Yorkshire terrier with mild generalized ataxia and intermittent neck scratching led to a diagnosis of caudal occipital malformation and syringohydromyelia. Surgical exploration led to a diagnosis of occipital dysplasia with concurrent occipital hypoplasia. Following a dorsal laminectomy of the first cervical vertebra there was no progression or improvement a month later.  相似文献   

15.
This study was performed to characterize pulmonary embolism with computed tomography pulmonary angiography in experimental pulmonary embolism and heartworm infected dogs. In the experimental group, there were pulmonary changes after pulmonary embolism induction as follows: hypoattenuating round filling defects in pulmonary arteries, arterial dilations with straight and abrupt cut‐off appearances in the pulmonary embolism regions, pulmonary infarctions, a cavity formation and spontaneous pneumothorax, and emboli migration. In the heartworm‐infected group, three out of eight dogs developed pulmonary embolism, especially in the right caudal arteries. Arterial dilations with typical tortuosity were also identified, mainly in the right caudal arteries in five dogs. Computed tomography pulmonary angiography can be an important imaging modality in the diagnosis of pulmonary embolism and the evaluation of pulmonary arterial and parenchymal changes in dogs.  相似文献   

16.
OBJECTIVE: To determine whether frontal-sinus size is associated with syringohydromyelia. SAMPLE POPULATION: Medical records and magnetic resonance images of 62 small-breed dogs. PROCEDURES: Medical records and magnetic resonance images were reviewed retrospectively for evaluation of frontal-sinus size and syringohydromyelia. A Yates-corrected 2-tailed chi2 test was used to determine whether an association existed between absent or miniscule frontal sinuses and syringohydromyelia. The strength of the association was evaluated by means of prevalence and odds ratios. RESULTS: Absent or miniscule air-filled frontal sinuses were detected in 28 of 62 (45%) dogs, and syringohydromyelia was detected in 12 of 62 (19%) dogs. Syringohydromyelia was detected in 10 of 28 dogs with absent or miniscule frontal sinuses (prevalence, 36%; 95% confidence interval, 16% to 55%) and in 2 of 34 dogs with larger frontal sinuses (prevalence, 6%; confidence interval, 0% to 15%). The probability of detecting syringohydromyelia in dogs with absent or miniscule air-filled frontal sinuses was significantly greater than the probability of detecting it in dogs with larger frontal sinuses. The prevalence ratio was 6.1, and the odds ratio was 8.9. CONCLUSIONS AND CLINICAL RELEVANCE: An association between frontal-sinus size and syringohydromyelia was identified in small-breed dogs, suggesting that the pathogenesis of syringohydromyelia in some instances may involve abnormal development of the entire or supratentorial part of the cranium, as opposed to being limited to the infratentorial part.  相似文献   

17.
Hypoattenuating ocular lenses on CT have been described with cataract formation in humans, however published studies are currently lacking regarding this finding in veterinary patients. The purpose of this retrospective and prospective study was to describe the varying CT appearances of the ocular lens in vivo, and investigate the causes for CT density variations in a population of cats and dogs. A total of 102 canine and feline patients with CT of the head acquired at the authors’ hospital between May 2011 and March 2019 were included. A bilateral hypoattenuating halo surrounding an isoattenuating to mildly hypoattenuating core was described in the ocular lens center of every cat in which a Philips brand proprietary image construction filter was used. A similar but more varied hypoattenuating region was noted in the lenses of 45.8% of dogs where the same filter was applied, as well as 43.8% of dogs with a second, similar filter. Ophthalmic examination of three live cats and one dog with hypoattenuating lenses demonstrated normal lens translucency, excluding the presence of cataract. The effect of different proprietary filters on lens appearance was also described in three fresh cadavers with normal lenses identified on ophthalmic, macroscopic, and microscopic examination. Etiology of the hypoattenuating areas within the ocular lens was not conclusively determined. Recognition that such a variant may be seen in the absence of cataract is important, in order to prevent misdiagnosis.  相似文献   

18.
Canine pulmonary eosinophilic granulomatosis is a rare inflammatory pulmonary disease characterized by formation of eosinophilic granulomas that tend to obliterate the normal pulmonary architecture. The purpose of this retrospective study was to describe the CT characteristics of confirmed idiopathic pulmonary eosinophilic granulomatosis in a group of dogs. Five dogs met inclusion criteria. All patients were young adult dogs of variable breeds. No dog had concurrent occult heartworm disease. Computed tomographic characteristics most commonly included pulmonary masses and nodules of variable size, and lesions were most commonly located in the caudal lung lobes. Four dogs had large pulmonary masses with or without additional nodules and one dog had nodular lesions disseminated throughout the entire lung parenchyma. All large eosinophilic granulomas were smoothly margined, heterogeneous pulmonary masses displaying heterogeneous contrast enhancement. A honeycomb‐like enhancement pattern was observed in all but one mass and consisted of multiple hyperattenuating rims delineating central hypoattenuating areas, suggestive of bronchiectatic lung with peripheral enhancing airway walls and fluid‐filled, necrotic bronchial lumen. One dog had evidence of tracheobronchial lymphadenopathy. Findings indicated that canine eosinophilic pulmonary granulomatosis should be included as a differential diagnosis for dogs with CT characteristics of multiple pulmonary masses and/or nodules in caudal lung lobes, and a honeycomb‐like enhancement pattern in masses after intravenous administration of iodinated contrast medium.  相似文献   

19.
O bjectives : To investigate the possible association between caudal fossa area and cervical vertebral dimensions and the presence of syringomyelia in cavalier King Charles spaniels.
M ethods : From magnetic resonance imaging scans of 78 cavalier King Charles spaniels, measurements were made of the widest vertical spinal width at C1/C2, C2, C2/C3 and C3; angulation of the C2/C3 spine; and estimated caudal fossa area. A correlation between these measurements and syringomyelia was sought.
R esults : A total of 59 dogs with and 19 without syringomyelia were compared. Older dogs had a significantly higher incidence of syringo-myelia. No difference in incidence was noted between genders. There was no significant difference in vertebral canal width at C1/C2 and C2, or angulation of C2/C3 between syringomyelia and non-syringomyelia groups. The width of the canal at C2/C3 and C3 was significantly increased in syringomyelia dogs. There was no significant difference in the caudal fossa area between groups.
C linical S ignificance : Although syringomyelia was shown to be more prevalent in older dogs, the age beyond which dogs were considered at greater risk was not deducible from the dataset. The association identified between wider spinal canal at C3, and C2/C3 and syringomyelia presence is of questionable clinical significance, as the difference between syringomyelia and non-syringomyelia groups is too small to be measured in a clinical setting.  相似文献   

20.
Anencephaly occurred in four calves and was characterized by cranioschisis, absence of the diencephalon with the cerebral hemispheres and rostral midbrain, various forms of eye defects, and relatively normal development of caudal brain stem, cerebellum and spinal cord. Amorphous dysplastic vestiges of the cerebral tissue protruded into the cranial defects. Morphologic features varied but were essentially similar. The cerebellum was absent in one case. Anencephaly in calves at least those we observed and defined in this study is localized defect confined to the brain, eye and skull. No spinal defect was observed in the calves.  相似文献   

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