Publications by authors named "Roberto Jose Lopez"

Phosphatase and tensin homolog (PTEN) is a critical tumor suppressor gene with a vital role in regulating cell proliferation, migration, and survival. The loss of PTEN function, either by genetic alterations or decreased protein expression, is frequent in human gliomas and has been correlated with tumor progression, grade, therapeutic resistance, and decreased overall survival in patients with glioma. While different genetic mutations in PTEN gene have been occasionally reported in canine gliomas, no alterations in protein expression have been reported.

View Article and Find Full Text PDF
Article Synopsis
  • A head turn in dogs can indicate issues in the central nervous system (CNS) and is traditionally linked to forebrain dysfunction, but this study aims to explore other potential origins.
  • The research was conducted on 49 client-owned dogs presenting with head turns, using thorough neurological exams and advanced imaging techniques to analyze their conditions.
  • Results show that while many head turns were associated with forebrain issues, specific combinations of head and body postures indicated that other areas of the CNS, like the brainstem or cervical spinal cord, could also be involved, highlighting the need for careful classification of symptoms.
View Article and Find Full Text PDF
Article Synopsis
  • The study focused on 22 cats diagnosed with central cord syndrome (CCS) to analyze their clinical findings, diagnoses, and outcomes.
  • Most affected cats were around 9 years old, with prevalent lesions in the C1-C5 and C6-T2 spinal cord segments, often linked to ischemic myelopathy or neoplasia.
  • The prognosis was generally poor, with about 59% of the cats showing negative outcomes, especially in cases with chronic signs and specific underlying causes.
View Article and Find Full Text PDF

Gliomas are the second most common primary brain tumor in dogs and although they are associated with a poor prognosis, limited data are available relating to the efficacy of standard therapeutic options such as surgery, radiation and chemotherapy. Additionally, canine glioma is gaining relevance as a naturally occurring animal model that recapitulates human disease with fidelity. There is an intense comparative research drive to test new therapeutic approaches in dogs and assess if results translate efficiently into human clinical trials to improve the poor outcomes associated with the current standard-of-care.

View Article and Find Full Text PDF

Objectives: The aim of the study was to describe the patient demographics, clinicopathological features and presumptive or final diagnoses in cats with myelopathies between the T1 and T6 vertebrae.

Methods: This retrospective multicentre case study enrolled cases between 2015 and 2022 that were diagnosed with myelopathies between the T1 and T6 vertebrae as the primary cause for the presenting clinical signs.

Results: A total of 21 cases matched the inclusion criteria, 13 males (11 castrated and 2 entire) and 8 spayed females (median age 93 months; range 5-192).

View Article and Find Full Text PDF

A 5-month-old German Shepherd dog was presented with cluster seizures. MR imaging showed a large irregular pseudomass in the central region of the cranial cavity, compatible with a malformation of cortical development. Despite the extensive changes, the patient was neurologically normal interictally 1 year following diagnosis.

View Article and Find Full Text PDF

Recent work identified anti-GM2 and anti-GalNAc-GD1a IgG ganglioside antibodies as biomarkers in dogs clinically diagnosed with acute canine polyradiculoneuritis, in turn considered a canine equivalent of Guillain-Barré syndrome. This study aims to investigate the serum prevalence of similar antibodies in cats clinically diagnosed with immune-mediated polyneuropathies. The sera from 41 cats clinically diagnosed with immune-mediated polyneuropathies (IPN), 9 cats with other neurological or neuromuscular disorders (ONM) and 46 neurologically normal cats (CTRL) were examined for the presence of IgG antibodies against glycolipids GM1, GM2, GD1a, GD1b, GalNAc-GD1a, GA1, SGPG, LM1, galactocerebroside and sulphatide.

View Article and Find Full Text PDF
Article Synopsis
  • The study focused on understanding the traits, clinical signs, and diagnoses of dogs with lesions in the cranial thoracic spinal cord identified through advanced imaging at three veterinary specialty centers between 2009 and 2021.
  • A total of 84 dogs were examined, with most showing progressive symptoms lasting over four weeks, and the common findings included being ambulatory and a prevalent location of lesions at the T3-L3 spinal cord segments.
  • The leading diagnosis was neoplasia (cancer), followed by structural anomalies and degenerative disorders, with specific clinical signs such as short-strided gait or spinal hyperesthesia helping to identify the condition and guide treatment.
View Article and Find Full Text PDF

Familial cerebellar ataxia with hydrocephalus in Bullmastiffs was described almost 40 years ago as a monogenic autosomal recessive trait. We investigated two young Bullmastiffs showing similar clinical signs. They developed progressive gait and behavioural abnormalities with an onset at around 6 months of age.

View Article and Find Full Text PDF

Background: As they have been seldomly described in the veterinary literature, the aims of this retrospective study were to describe the clinical presentation, MRI findings and long-term outcome after medical or surgical treatment of dogs presenting with foraminal and far lateral thoracolumbar intervertebral disc herniations.

Methods: Retrospective multicentre study of dogs diagnosed with foraminal and far lateral thoracolumbar intervertebral disc herniations between 2009 and 2020 in seven referral hospitals.

Results: Thirty-seven dogs were included.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to describe the clinical signs, diagnostic processes, treatments, and outcomes for dogs diagnosed with acute central cord syndrome (CCS).
  • A total of 74 dogs from five referral hospitals were evaluated, revealing that most cases (88%) involved the C1-C5 spinal cord region, with common causes being disk herniations.
  • The majority of dogs (93%) showed favorable outcomes after treatment, although those with respiratory issues had significantly worse prognoses.
View Article and Find Full Text PDF

Background: Orthostatic tremor (OT) is a rare movement disorder characterized by high-frequency (>12 Hz) involuntary, rhythmic, sinusoidal movements affecting predominantly the limbs while standing.

Objective: To describe the signalment, presenting complaints, phenotype, diagnostic findings, treatment, and outcome of a large sample of dogs with OT.

Animals: Sixty dogs diagnosed with OT based on conscious electromyography.

View Article and Find Full Text PDF

Standardized veterinary neuroimaging response assessment methods for brain tumours are lacking. Consequently, a response assessment in veterinary neuro-oncology (RAVNO) system which uses the sum product of orthogonal lesion diameters on 1-image section with the largest tumour area, has recently been proposed. In this retrospective study, 22 pre-treatment magnetic resonance imaging (MRI) studies from 18 dogs and four cats with suspected intracranial neoplasia were compared by a single observer to 32 post-treatment MRIs using the RAVNO system and two volumetric methods based on tumour margin or area delineation with HOROS and 3D Slicer software, respectively.

View Article and Find Full Text PDF

Dorsal atlantoaxial stabilisation (DAAS) has mostly been described to treat atlantoaxial instability using low stiffness constructs in dogs. The aim of this study was to assess the feasibility and surgical outcome of a rigid cemented DAAS technique using bone corridors that have not previously been reported. The medical records of 12 consecutive dogs treated with DAAS were retrospectively reviewed.

View Article and Find Full Text PDF
Article Synopsis
  • This study evaluated the effectiveness of neostigmine methylsulfate in diagnosing acquired myasthenia gravis (MG) in dogs and cats from 2017 to 2019.
  • Out of 25 animals (22 dogs and 3 cats) with clinical signs of MG, 16 dogs were diagnosed with the condition, with 13 responding positively to the neostigmine challenge.
  • The results suggest that the neostigmine challenge may be a safe and effective alternative to the previously used edrophonium challenge for diagnosing MG.
View Article and Find Full Text PDF

Background: Gliomas in dogs remain poorly understood.

Objectives: To characterize the clinicopathologic findings, diagnostic imaging features and survival of a large sample of dogs with glioma using the Comparative Brain Tumor Consortium diagnostic classification.

Animals: Ninety-one dogs with histopathological diagnosis of glioma.

View Article and Find Full Text PDF

Objective: To describe the clinical presentation, magnetic resonance imaging (MRI) findings, and outcome of dogs treated surgically for lumbosacral intervertebral disk extrusion (IVDE).

Study Design: Retrospective study.

Animals: Thirteen dogs.

View Article and Find Full Text PDF

Objective: To report the diagnosis and clinical management of a case of suspected intracranial hypovolemia (IH) in a dog after resection of a large fronto-olfactory chordoid meningioma.

Study Design: Clinical case report.

Animal: One 8-year-old border collie with forebrain neurological signs caused by a fronto-olfactory extra-axial mass diagnosed by using MRI.

View Article and Find Full Text PDF

Background: The pathophysiology of changes in magnetic resonance imaging (MRI) detected after a seizure is not fully understood.

Objective: To characterize and describe seizure-induced changes detected by MRI.

Animals: Eighty-one client-owned dogs diagnosed with idiopathic epilepsy.

View Article and Find Full Text PDF

Background: Traumatic skull fractures (TSF) are relatively frequent in dogs and cats, but little information is available regarding their clinical and imaging features.

Hypothesis/objectives: To describe the neurological and computed tomographic (CT) features of a large cohort of dogs and cats with TSF.

Animals: Ninety-one dogs and 95 cats with TSF identified on CT.

View Article and Find Full Text PDF

Background: Although the presence of seizures in dogs with meningoencephalitis of unknown origin (MUO) has been associated with shorter survival times, data regarding the prevalence and risk factors for postencephalitic epilepsy (PEE) is lacking.

Objectives: To describe the clinical features, prevalence, risk factors, and long-term outcome of PEE in dogs with MUO.

Animals: Sixty-one dogs with presumptive diagnosis of MUO based on the clinicopathological and diagnostic imaging findings.

View Article and Find Full Text PDF

Dogs develop gliomas with similar histopathological features to human gliomas and share with them the limited success of current therapeutic regimens such as surgery and radiation. The tumor microenvironment in gliomas is influenced by immune cell infiltrates. The present study aims to immunohistochemically characterize the tumor-infiltrating lymphocyte (TIL) population of naturally occurring canine gliomas, focusing on the expression of Forkhead box P3-positive (FOXP3+) regulatory T-cells (Tregs).

View Article and Find Full Text PDF

Vertebral lesions and associated neurological signs occur in dogs with multiple myeloma, however, veterinary literature describing MRI findings is currently lacking. The objective of this multicenter, retrospective, case series study was to describe neurological signs and MRI findings in a group of dogs that presented for spinal pain or other neurological deficits and had multiple myeloma. Electronic records of four veterinary referral hospitals were reviewed.

View Article and Find Full Text PDF

Reports of medulloblastoma in cattle are scarce; however, this neoplasm should be included as a differential diagnosis in cases of cerebellar or central vestibular signs in young cattle. The MRI appearance of the medulloblastoma reported here, previously unreported in cattle, consisted of a T1-weighted hypointense and T2-weighted heterogeneously hyperintense intra-axial mass.

View Article and Find Full Text PDF