Short- and long-term outcome and magnetic resonance imaging findings after surgical treatment of thoracolumbar spinal arachnoid diverticula in 25 Pugs.

BACKGROUND: There is a successful outcome after surgical management of spinal arachnoid diverticula (SAD) in up to 82% of cases. HYPOTHESIS/OBJECTIVES: We hypothesized that Pugs have favorable short-term and poor long-term prognosis after surgical treatment of thoracolumbar SAD. The aim of the present investigation was to describe clinical findings, short- and long-term outcomes, and follow-up magnetic resonance imaging (MRI) findings in Pugs with thoracolumbar SAD. ANIMALS: Twenty-five client owned Pugs with 12-month follow-up information after surgical treatment of thoracolumbar SAD. METHODS: Multicenter retrospective case series. All medical records were searched for Pugs diagnosed with SAD. Data regarding signalment, history, surgical procedure, outcome, histopathology, and follow-up MRI results were extracted. RESULTS: Mean age at presentation was 7.32 (range 2-11) years, 80% were males. Short-term outcome was available in 25 dogs, and improvement was confirmed in 80% of dogs. Long-term outcome was available in 21 dogs, and deterioration was confirmed in 86% of cases, with late-onset recurrence of clinical signs after initial postsurgical improvement affecting 85% of Pugs. A moderate correlation (r = 0.50) was found between duration of clinical signs and outcome. In 8 dogs with deteriorating clinical signs, follow-up MRI revealed regrowth of the SAD in 2 cases, new SAD formation in 2 cases, and intramedullary T2W hyperintensity/syringomyelia in 6 cases. CONCLUSIONS AND CLINICAL IMPORTANCE: This study suggests that Pugs with thoracolumbar SAD do not have a favorable long-term prognosis after surgical treatment for reasons yet to be determined.

Decreased plasminogen activator inhibitor and tissue metalloproteinase inhibitor expression may promote increased metalloproteinase activity with increasing duration of human atrial fibrillation.

INTRODUCTION: Atrial fibrosis has been shown to concur with the persistence of atrial fibrillation (AF) and is only incompletely reversible, thus counteracting attempts to restore and maintain sinus rhythm (SR). Besides the angiotensin system, the matrix metalloproteinases (MMP) play a major role in the pathogenesis of fibrosis. Thus, the present study investigated changes of the MMP system during the development of human AF. METHODS AND RESULTS: Right atrial appendages of 146 patients were excised during heart surgery and grouped according to rhythm (SR vs AF) and AF duration. Hydroxyproline as a surrogate for collagen content and morphometrically determined collagen content increased significantly from SR (14.3 +/- 7.7%) to chronic permanent AF (CAF) of 6-24 months (21.2 +/- 9.2%, P = 0.02), and CAF of > 60 months (25.3 +/- 4.7%, P < 0.01). From SR to paroxysmal and chronic persistent AF (CPAF) and to CAF MMP-2 and MMP-9 activity rose, while their mRNA and protein levels were not altered significantly. Plasminogen activator inhibitor (PAI), an inhibitor of a potent activator of many MMPs, was significantly decreased with increasing duration of AF. In parallel, the mRNA levels of the tissue inhibitors of MMPs TIMP-1 and -2 decreased significantly. CONCLUSION: Human atrial fibrogenesis is enhanced with increasing duration of AF: a longer AF duration is associated with elevated atrial interstitial MMP activity, but decreased PAI and TIMP expression.

Feline hippocampal and piriform lobe necrosis as a consequence of severe cluster seizures in two cats in Finland.

Feline hippocampal and piriform lobe necrosis (FHN) has been reported from several countries worldwide and is considered an important aetiology for feline epileptic seizures. The aetiology of FHN remains unclear, however it is suspected that FHN might occur secondary to intense epileptic activity as described in humans and dogs although this has not yet been documented in cats. The purpose of our report is to describe the first cases of FHN in Finland diagnosed by magnetic resonance imaging (MRI) and histopathology. The two cases we describe had a well documented history of pre-existing seizures with normal brain MRI at the onset of cluster seizures but MRI done when the cats exhibited clinical deterioration secondary to severe seizure activity, revealed lesions in the hippocampus and piriform lobes typical of FHN. Our report confirms that feline hippocampus and piriform lobe necrosis does occur in the Finnish cat population and should therefore be considered as a differential diagnosis in cats with seizures. In addition, the presentation, clinical findings, results of MRI and/or histopathology shows that cats may develop FHN secondary to severe seizure activity.

Spinal dural ossification causing neurological signs in a cat.

A six-year-old Ragdoll cat underwent examination due to a six-month history of slowly progressive gait abnormalities. The cat presented with an ambulatory tetraparesis with a neurological examination indicating a C1-T2 myelopathy. Radiographs of the spine showed a radiopaque irregular line ventrally in the vertebral canal dorsal to vertebral bodies C3-C5. In this area, magnetic resonance imaging revealed an intradural extramedullary/extradural lesion compressing the spinal cord. The spinal cord was surgically decompressed. The cause of the spinal cord compression was dural ossification, a diagnosis confirmed by histopathological examination of the surgically dissected sample of dura mater. The cat gradually improved after the procedure and was ambulating better than prior to the surgery. The cat's locomotion later worsened again due to ossified plaques in the dura causing spinal cord compression on the same cervical area as before. Oral prednisolone treatment provided temporary remission. Ten months after surgery, the cat was euthanized due to severe worsening of gait abnormalities, non-ambulatory tetraparesis. Necropsy confirmed spinal cord compression and secondary degenerative changes in the spinal cord on cervical and lumbar areas caused by dural ossification. To our knowledge, this is the first report of spinal dural ossification in a cat. The reported cat showed neurological signs associated with these dural changes. Dural ossification should be considered in the differential diagnosis of compressive spinal cord disorders in cats.

Increased postoperative peritoneal adhesion formation after the treatment of experimental peritonitis with chlorhexidine.

BACKGROUND AND AIMS: Chlorhexidine is known as a substance that produces adhesions. However, in an experimental model of peritoneal injury, lavage with chlorhexidine and saline solutions produced a similar number of adhesions. This study was designed to test the hypothesis that chlorhexidine gluconate 0.05% solution used for the treatment of peritonitis increases formation of postoperative peritoneal adhesions as compared to standard lavage with saline solution. MATERIAL AND METHODS: Forty Wistar rats were randomly allocated to gastric or faecal peritonitis groups. In each group rats were further randomly subdivided into saline or chlorhexidine peritoneal lavage groups. After 30 days the rats were killed and intraperitoneal adhesions were evaluated by adhesion score and grading. RESULTS: Adhesion scores were statistically significantly different between saline and chlorhexidine groups in both gastric and faecal peritonitis models. In the faecal peritonitis chlorhexidine group a 20% small bowel intussusception rate was observed, while there were no such complications in the other study groups. The conglomerate of organs formed by dense adhesions was present in 60% of cases when gastric peritonitis was lavaged by chlorhexidine and in only 10% when saline solution was used ( P<0.05). Neither chlorhexidine nor saline solutions have caused such dense adhesions in faecal peritonitis. CONCLUSION: Peritoneal lavage with chlorhexidine gluconate 0.05% solution in the treatment of experimental peritonitis results in increased adhesion formation.