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P R Gavin

Publications and source records attributed to P R Gavin.

42 records · Page 3Linked to original sources

Magnetic resonance imaging features of equine nigropallidal encephalomalacia.

Magnetic resonance imaging (MR) was used to make a diagnosis of equine nigropallidal encephalomalacia in a horse. Equine nigropallidal encephalomalacia is a neurodegenerative disease that has many characteristics with Parkinson-like diseases in humans. Historically, horses were euthanized based on clinical signs and exposure to the toxic weed, yellow star thistle (Centaurea solstitialis). Previously, the disease has only been confirmed on necropsy. MR imaging can provide accurate and sensitive visualization of typical lesions seen in the brain of horses affected with equine nigropallidal encephalomalacia. Lesions were seen on T1-weighted, T2-weighted and proton density images. There was no contrast enhancement following Gd-DTPA administration. Lesions seen on MR were confirmed at necropsy. Using MR to confirm a diagnosis of equine nigropallidal encephalomalacia will prevent unnecessary suffering of horses and expense to owners that would otherwise incur, while further diagnostics are performed.

Animals↗

Retrospective review of 50 canine intracranial tumors evaluated by magnetic resonance imaging.

Magnetic resonance imaging (MRI) was performed on 50 dogs with intracranial neoplasia. The following tumor features were assessed: axial origin, location, shape, growth pattern, MRI signal intensity, evidence for edema, and paramagnetic contrast enhancement. Histologic diagnosis included 5 intracranially invading nasal tumors, 7 pituitary tumors, 22 meningiomas, 6 choroid plexus tumors, 7 astrocytomas, 1 ependymoma, and 2 oligodendrogliomas. Axial origin, site, shape, and growth pattern were important diagnostic characteristics for tumor type. Signal intensity and contrast enhancement pattern allowed further differentiation. Characteristic MRI features that facilitate diagnosis and prognosis were identified. Accurate diagnosis of tumor type based on these features was not always possible because of similarities in MRI appearance for some tumors. Tissue biopsy remains necessary for definitive diagnosis of intracranial tumors.

Adenocarcinoma↗

Clinical features of trigeminal nerve-sheath tumor in 10 dogs.

Nerve-sheath tumor was diagnosed in 10 dogs with clinical signs of unilateral trigeminal nerve dysfunction. Unilateral temporalis and masseter muscle atrophy were present in all cases. An enlarged foramen and distorted rostral petrous temporal bone were seen with computed tomography imaging in one case. Magnetic resonance imaging was used to identify the lesion accurately in seven cases. Surgery was performed for biopsy and lesion removal in three cases. Cases not treated had a progressive course eventually resulting in euthanasia or death. Of the cases treated surgically, one case is alive without disease progression 27 months after surgery. Survival times of the nontreated cases ranged from five to 21 months.

Animals↗

Cerebellar cystic meningioma in a dog.

A 21-kg, seven-year-old, male, mixed-breed Labrador retriever was admitted for incoordination and a head tilt of approximately three months' duration. Ataxia was noted of the trunk and limbs, and there was a head tilt to the right side. Conscious proprioceptive deficits were present in the left thoracic and pelvic limbs (i.e., hemiparesis). These abnormalities were consistent with paradoxical vestibular syndrome and a lesion involving the caudal cerebellar peduncle. A mass lesion consisting primarily of fluid was present on magnetic resonance imaging and at craniectomy. Histopathological diagnosis was a cystic meningioma. Based upon previous reports and experience, the location of this tumor was unusual.

Animals↗