Brain Exam Papers 2025 PDF

Large animals Brain – General – Examination................................................................................................................................. 2 Brain – Anatomy.................................................................................................................

Large animals Brain – General – Examination................................................................................................................................. 2 Brain – Anatomy..................................................................................................................................................... 4 Brain – CSF............................................................................................................................................................ 6 Brain – HTIC......................................................................................................................................................... 19 Brain – Congenital malformation........................................................................................................................... 21 Brain – Epilepsy.................................................................................................................................................... 24 Brain – Congenital................................................................................................................................................ 30 Brain – Metabolic encephalopathy........................................................................................................................ 32 Brain – Degenerative – TPO................................................................................................................................... 36 Brain – Inflam – General........................................................................................................................................ 38 Brain – Inflam - Meningoencephalomyelitis – Bacterial........................................................................................... 41 Brain – Inflam - Meningoencephalomyelitis – Viral.................................................................................................. 45 Brain – Inflam – Meningoencephalomyelitis – Parasites.......................................................................................... 52 Brain – TSE........................................................................................................................................................... 54 Brain – Neoplasia................................................................................................................................................. 56 Brain – Cranial nerves........................................................................................................................................... 58 Brain – Miscellanous............................................................................................................................................. 61 Movements disorders........................................................................................................................................... 64 Pharmacology...................................................................................................................................................... 76 Exotic animals...................................................................................................................................................... 80 Wild Animals........................................................................................................................................................ 83 Articles – examen 2025 – RC 1 / 90 Brain – General – Examination Articles – examen 2025 – RC 2 / 90  Interobserver Variation in the Diagnosis of Neurologic Abnormalities in the Horse, JVIM 2017 - Objective: To investigate the level of agreement between board-certified veterinary internists when performing neurologic examinations in horses. - Animals: Ninety-seven horses admitted to the Veterinary Teaching Hospital at The Ohio State University from December 1997 to June 1998. - Methods: A prospective epidemiologic research design was used. Horses enrolled in the study were examined by the internist responsible for care of the horse, and later by an internist who was not aware of the presenting complaint or other patient history. - Results: 97 horses were enrolled in the study. ▪ Observers, agreed: 61.9% were clinically abnormal, 21.6% were clinically normal, and the 16.5% with contested status. ▪ Complete agreement among the examiners with regard to cranial nerve signs and involuntary movements. ▪ Disagreement involving severity of clinical signs occurred in 31 horses, and 25 of those horses (80.6%) were considered either normal or mildly affected by the primary observer. ▪ When examining the results of all paired clinical examinations for 11 different categories, there was wide variability in the results. When examiners rated the presence or absence of any neurologic abnormalities, lameness, or ataxia, the agreement among observers was either good or excellent for 80% of horses. When assessing truncal sway, the agreement among observers was good or excellent for 60% of the horses. When examining the horses for asymmetry of deficits, agreement was either good or excellent for 40% of the horses. Agreement among obser- vers was excellent or good for only 20% of the horses when assessing muscle atrophy, spasticity (hypermetria), and overall assessment of the severity of neurologic abnormalities. - Conclusions and Clinical Importance: This study underscores the subjectivity of the neurologic examination and demon- strates a reasonable level of agreement that may be achieved when different clinicians examine the same horse. Articles – examen 2025 – RC 3 / 90 Brain – Anatomy Articles – examen 2025 – RC 4 / 90  An anatomical study of the subarachnoid space surrounding the trigeminal ganglion in horses—in preparation for a controlled glycerol rhizotomy in equids, Front 2024 Introduction: Equine trigeminal-mediated headshaking is a painful neuropathic disorder comparable to trigeminal neuralgia in humans. The selective destruction of pain fibers within the trigeminal ganglion, called rhizotomy, is he surgical treatment of choice for idiopathic trigeminal neuralgia refractory to medical treatment in humans. The human trigeminal ganglion is enclosed by a dural recess called the Meckel’s or trigeminal cave, in which the ganglion is surrounded by a cerebrospinal fluid (CSF)-filled subarachnoid space. During glycerol rhizotomy, glycerol is percutaneously injected in this CSF-filled space. Until now, information about the anatomy of the dural recess and the subarachnoid space surrounding the trigeminal ganglion is lacking in horses. Cadaveric study: Six equine cadaver heads were investigated for CSF accumulation around the ganglion with a 3 Tesla MRI. After anatomical dissection to expose the trigeminal root, a polymer-based radiopaque contrast agent was injected through the porus trigeminus into the subarachnoid space (cisternography). The exact delineation and the volume of the contrast agent accumulation were determined on subsequent micro-computed tomographic scans and segmentation. Finally, the distribution of the contrast agent within the subarachnoid space was examined histologically in three specimens. Results: In all 12 specimens included in this study, the trigeminal ganglion was surrounded by a subarachnoid space forming a trigeminal cistern. The mean volume of the trigeminal cave in this study was 0.31 mL (±SD: 0.11 mL). Distribution of the contrast agent along the peripheral nerves (i.e., ophthalmic, maxillary and/or mandibular nerve) was observed in 7 out of 12 specimens. Discussion: A subarachnoid space surrounding the trigeminal ganglion exists in the horse and could be targeted for glycerol rhizotomy in horses suffering from trigeminal-mediated headshaking. However, the clinical relevance of contrast agent distribution along the peripheral nerves remains to be assessed. Schéma ++ Articles – examen 2025 – RC 5 / 90 Brain – CSF Articles – examen 2025 – RC 6 / 90  Survival associated with cerebrospinal fluid analysis in downer adult dairy cows: A retrospective study (2006-2014), JVIM 2018 - Background: Threshold values for total nucleated cell count (TNCC) and protein concentration in cerebrospinal fluid (CSF) of downer dairy cows suggestive of a spinal cord lesion were recently published. TNCC) >4.5 cells/μL and/or a protein concentration >0.39 g/L yielded a specificity of 100% for the presence of a spinal cord lesion in downer dairy cows. - Objectives: Determine short- and long-term survival of downer cows that underwent CSF analysis using the reported threshold values. Evaluate the prognostic value of these threshold values to predict short- and long-term survival. - Animals: 214 downer adult dairy cows that underwent CSF analysis. Retrospective study. - Results: ▪ Cows with CSF TNCC and/or protein concentration above the threshold values had a significantly lower short-term survival rate. The odds of nonsurvival of cows with one or both CSF values above the threshold values was 2.16 times higher than the odds for cows with values under the threshold values. ▪ CSF TNCC >4.5 cells/μL had sensitivity and specificity of 17.3% (95% CI: 10.7%-25.7%) and 92.3% (95% CI: 85.4%-96.6%), respectively, for predicting short-term nonsurvival. ▪ CSF protein concentration >0.39 g/L had sensitivity and specificity of 20.9% (95% CI: 13.7%- 29.7%) and 91.4% (95% CI: 84.2%-96.0%), respectively. - Conclusions: CSF analysis above threshold values used in this study is associated with increased odds of short-term nonsurvival. Articles – examen 2025 – RC 7 / 90  Comparison of 2 collection methods for cerebrospinal fluid analysis from standing, sedate adult horses, JVIM 2020 - Animals: 15 normal horses and 9 horses with signs of neurologic disease. Prospective study. Cerebrospinal fluid collection from the LS space and C1-C2 space of each horse was performed in randomized order. - Results: ▪ Cerebrospinal fluid collected from the C1-C2 site had a significantly lower mean protein concentration (49 vs 52.1 mg/dL) and red blood cell count (6/μL vs 33). ▪ Collection time, total nucleated cell count, EPM titers, and serum:CSF EPM titer ratios were not significantly different. - Conclusions: Cerebrospinal fluid from the C1-C2 space provides an acceptable alternative to LS CSF collection with decreased likelihood of clinically important blood contamination of samples. Opioid-free sedation for atlantoaxial cerebrospinal fluid collection in adult horses, JVIM 2022 - Procedure times were lower in horses sedated with DX (detomidine - xylazine), compared to D0 (detomidine alone). - Procedure reaction scores were lower in horses sedated with DX or DM compared to DO - Reactions to dura mater puncture were recorded in 3 of 6 horses in D0 and DD groups, and 0 of 6 horses in DX and DM groups. Positive associations were observed between reaction score vs total distance or farthest excursion distance from baseline. Both opioid-free and morphine-containing sedation protocols are acceptable for AA CSF collection. Motion-tracking software represents a novel method for assessing sedation in standing horses. Articles – examen 2025 – RC 8 / 90  Comparison of Fluid Analysis and Cytologic Findings of Cerebrospinal Fluid Between Three Collection Sites in Adult Equids With Neurological Disease, Front 2022 113 equids aged ≥1 - CSF samples obtained from the three sites were compared. - When comparing all samples, LS centesis was associated with higher RBC compared to other sites - TP was lower in the AA group than in the LS group - Within a subset of cytologically unremarkable samples, RBC concentration was highest in LS sample; TP was higher in LS samples compared to AA samples and TNCC was higher in AA and LS groups compared to the AO. - In cytologically abnormal samples, there were no significant differences between sites in any parameter. - Abnormal cytology was correlated with non-survival. Non-survival was associated with higher TNCC. The receiver operating characteristic (ROC) curve for TNCC had an area under the curve of 0.67 (95% CI, 0.55–0.79) and indicated that a cutoff value of 24 cells/μL maximized specificity (72%) and sensitivity (54%) to predict non-survival in all horses. Positive predictive value was 45%; negative predictive value was 78%. The concentration of RBC was higher in samples from the LS site. This has clinical implications due to the importance of comparative diagnostics and its potential impact on cytologic evaluation. There were minimal differences in multiple other parameters between sites, which are likely clinically insignificant. Articles – examen 2025 – RC 9 / 90  Effects of coadministration of corn oil and ponazuril on serum and cerebrospinal fluid concentrations of ponazuril in horses, JVIM 2020 - Background: Ponazuril is used for the treatment of EPM. Coadministration of ponazuril with oil could result in higher serum and cerebrospinal fluid concentrations. - Animals: 10 either sex and >2 years of age. Cohort study. - Results: ▪ Higher concentrations of ponazuril in serum (at steady state) than that found in horses given ponazuril alone (6.2 ± 0.9 mg/L versus 4.5 ± 1.0 mg/L) ▪ CSF concentrations of ponazuril were also greater in horses that received ponazuril and oil (0.213 mg/L ± 0.04 versus 0.162 ± 0.04 mg/L). Articles – examen 2025 – RC 10 / 90 The effect of prior thecal puncture on cerebrospinal fluid analytes in normal adult horses, JVIM 2020 Prospective study. Horses were randomly assigned to undergo CSF collection twice, 14 days apart, from either the C1-C2 or LS space. After a 4-month washout period, CSF collection was repeated from the alternate site. Results: There was no significant effect of collection day (day 0 or day 14) for any CSF analytes, including protein concentration, or nucleated cell count. There was no significant difference in EPM titer or EPM serum : CSF ratio between days 0 and 14. Articles – examen 2025 – RC 11 / 90 Opioid-free sedation for atlantoaxial cerebrospinal fluid collection in adult horses, JVIM 2022 Background: Atlantoaxial (AA) cerebrospinal fluid (CSF) collection in standing horses utilizes the controlled narcotic morphine, thereby limiting feasibility in field practice settings. Objectives: To compare AA CSF collection time and reaction scores in horses sedated with morphine-containing and opioid-free sedation protocols: detomidine + morphine (DM), detomidine + xylazine (DX), detomidine + detomidine (DD), detomidine alone (D0) Animals: Six healthy adult horses. Randomized crossover. Atlantoaxial CSF collections were performed weekly for 4 weeks. Horses received sedation protocols in random order. Results: Procedure times were lower in horses sedated with DX (median: 36 seconds; range: 28 188), compared to D0 (121; 35 196; P = 0.04). Procedure reaction scores were lower in horses sedated with DX (median 1.0, range 1.0 to 2.0), or DM (1.8; 1.3 3.0) compared to DO (3.0; 2.3 3.0; P =.03). Reactions to dura mater puncture were recorded in 3 of 6 horses in D0 and DD groups, and 0 of 6 horses in DX and DM groups. Positive associations were observed between reaction score vs total distance or farthest excursion distance from baseline. Conclusions and Clinical Importance: Both opioid-free and morphine-containing sedation protocols are acceptable for AA CSF collection. Motion-tracking software represents a novel method for assessing sedation in standing horses. Articles – examen 2025 – RC 12 / 90  Interpretation of cerebrospinal fluid analysis from recumbent cows using different thresholds of red blood cell count, JVIM 2022 Background: Hemodilution of the cerebrospinal fluid (CSF) could confound interpretation of results. Objective: To determine the effects of hemodilution on TPC and TNCC in bovine CSF. Methods: Retrospective review of 235 CSF analysis results of downer dairy cows. Results: - Red Blood cell (RBC) count (RBCC) ranged from 0 to 869 220 RBC/μL (median = 6.6), TPC ranged from 0.04 to 6.51 g/L (median = 0.27), and TNCC ranged from 0 to 7500 cell/μL (median = 1.1). - Among the 157 samples that had T, p.Arg1681*) in CACNA1A. The other affected calves (N=8) were heterozygous for the variant but it was absent in the other unaffected calves (N = 7) and parents of the sire. This variant was also absent in sequence data from over 6500 other cattle obtained via public repositories and collaborator projects. - The variant in CACNA1A is expressed in the cerebellum of the ataxic calves as detected in the transcriptome and was not differentially expressed compared with controls. The CACNA1A protein is part of a highly expressed cerebellar calcium voltage gated channel. The nonsense variant is proposed to cause haploinsufficiency, preventing proper transmission of neuronal signals through the channel and resulting in BFCA. Articles – examen 2025 – RC 26 / 90  Investigation of Known Genetic Mutations of Arabian Horses in Egyptian Arabian Foals with Juvenile Idiopathic Epilepsy, JVIM 2018 - Background: The carrier status of lavender foal syndrome (LFS), cerebellar abiotrophy (CA), severe combined immunodeficiency (SCID), and occipitoatlantoaxial malformation (OAAM1) in foals with juvenile idiopathic epilepsy (JIE) is unknown. - Animals: Ten foals with JIE. - Results: Ten Egyptian Arabian horses (5 females and 5 males) were phenotyped as foals with JIE by EEG. All foals were negative for the genetic mutations that cause LFS, CA, SCID, and OAAM1 except for 1 foal that was a carrier of CA. - Conclusions and Clinical Importance: Juvenile idiopathic epilepsy of Egyptian Arabian foals and LFS appear to be phenotypically and genetically distinct disorders. There was no apparent association between JIE and LFS, CA, SCID, and OAAM1. Articles – examen 2025 – RC 27 / 90  Electroencephalographic evaluation understanding sedation using sublingual detomidine hydrochloride in Egyptian Arabian foals for investigation of epilepsy, JVIM 2023 Background: A standardized protocol for electroencephalography (EEG) understanding sedation for the investigation of epilepsy in foals is needed. Animals: 19 foals (controls, 9; juvenile idiopathic epilepsy [JIE], 10). Descriptive clinical study. Results: - Level of sedation was considered excellent with no need of redosing. - The EEG recording lasted from 27 to 51 minutes and provided interpretable data. - Epileptic discharges (ED) were noted predominantly in the central-parietal region in 9 of 10 epileptic foals. - Photic stimulation triggered ED in 7 of 10 epileptic foals and in none of the controls. - Foals were not oversedated and recovered uneventfully. Conclusions: Sublingual detomidine hydrochloride is a safe, painless, simple, and effective method of sedation for EEG recording in foals. Sublingual sedation allowed the investigation of cerebral electrical activity during states of sleep and arousal, and during photic stimulation for the investigation of epilepsy in foals. Articles – examen 2025 – RC 28 / 90  Juvenile idiopathic epilepsy in Egyptian Arabian foals, a potential animal model of self-limited epilepsy in children, JVIM 2024 Retrospective study 69 foals (JIE, 48; controls, 21) Results: - Abnormalities on EEG were found in 95% of epileptic foals (35 of 37) and in 3 of 21 control asymptomatic foals with affected siblings. - Focal ED were detected predominantly in the central vertex with diffusion into the centroparietal or frontocentral regions (n = 35). Generalization of ED occurred in 14 JIE foals. - Epileptic discharges commonly were seen during wakefulness (n = 27/37 JIE foals) and sedated sleep (n = 35/37 JIE foals; 3/21 controls). - Photic stimulation triggered focal central ED in 15 of 21 JIE foals. Conclusions: Juvenile idiopathic epilepsy has a focal onset of ED at the central vertex with spread resulting in clinical generalized tonic-clonic seizures with facial motor activity and loss of consciousness. Electroencephalography with photic stimulation contributes to accurate phenotyping of epilepsy. Articles – examen 2025 – RC 29 / 90 Brain – Congenital Articles – examen 2025 – RC 30 / 90  A novel missense variant in the RELN gene in sheep with lissencephaly and cerebellar hypoplasia, Vet Path 2024 Lissencephaly and cerebellar hypoplasia (LCH) represents a spectrum of congenital developmental malformations of the cerebral cortex and cerebellum, mostly occurring as inherited conditions caused by variants in an increasingly recognized number of genes. LCH has been identified in three Dorset-cross lambs with congenital neurological signs in Australia. Lambs were unable to walk and had reduced vision, and one lamb developed a hypermetric gait and intention tremors. - Grossly, the lambs had diffuse pachygyria with reduction in white matter, mild bilateral ventriculomegaly of the lateral ventricles, and a markedly hypoplastic cerebellum. - Histologically, there was disorganization of neurons within the cerebral cortex and hippocampus. The cerebellar vermis had disorganized, thin, and hypocellular gray matter with frequent ectopic Purkinje cells, while identifiable folia were largely absent within the hemispheres. Luxol fast blue stain and glial fibrillary acidic protein, neuronal nuclear protein, synaptophysin, and neuron- specific enolase immunohistochemistry confirmed the thickened, disorganized cerebral cortical gray matter and reduced white matter. Within the cerebellum, immunohistochemistry demonstrated marked dysplasia. - Pathological and genetic findings are consistent with previously described phenotypes of RELN variants in Churra sheep, dogs, and humans. Photo ++ Articles – examen 2025 – RC 31 / 90 Brain – Metabolic encephalopathy Articles – examen 2025 – RC 32 / 90 Neonatal Encephalopathy in Calves Presented to a University Hospital, JVIM 2017 - Hypothesis/Objectives: To identify risk factors for development of NE in calves and factors predictive of survival. Animals: Neonatal calves presented to a University hospital over a 10-year period. Retrospective cohort study (2005–2015). Medical records of all neonatal calves presented to the hospital were examined, and cases of NE were identified. - Results: Of 200 calves in the final analysis, 29% were classified as NE ▪ Univariate analysis, factors significantly associated with diagnosis of NE: male sex, presence of dystocia, abnormal position in the birth canal, and prolonged labor. ▪ Multivariate model, only orientation of the calf in the birth canal remained significant (OR 2.14; 95% CI: 1.02–4.49; P = 0.044). ▪ Overall survival of calves with NE was good (77.6%); dam parity and being a twin was significantly associated with nonsurvival. - Conclusions: Calves born after dystocia, especially if malpresented, should be closely monitored for nursing behavior within the first 24h of life. Prognosis for survival is good, but supportive care might be required for several days. Articles – examen 2025 – RC 33 / 90  Presumed Neuroglycopenia Caused by Severe Hypoglycemia in Horses, JVIM 2018 - Animals: 90 horses (hours to 28 years of age) diagnosed with hypoglycemia (blood glucose concentration < 75 mg/dL. Retrospective study. - Results: 38 mild (50-74 mg/dL), and 52 severe hypoglycemia (< 50 mg/dL) ▪ Most common causes = liver and gastrointestinal (40%) disease, sepsis (33%), neoplasia (7%), and insulin- induced (4%). ▪ Most common neurologic deficits included obtundation (100%), seizures (42%), and disorientation (22%). ▪ CSF-glucose was severely low (mean 2.5 mg/dL [0.1 mmol/L], median 0 mg/dL). ▪ Paroxysmal discharges in support of seizures were identified in the occipital (visual) and parietal (closest to temporal-auditory) cortical regions upon EEG examination (8/8 horses). - Conclusions: Neuroglycopenia is presumed to occur in horses as the result of severe hypoglycemia. Subclinical seizures, and intermittent blindness and deafness of cortical origin can occur. Severe altered state of consciousness and seizures can be observed at a blood glucose cut-off value of < 42 mg/dL (< 2.3 mmol/L). Articles – examen 2025 – RC 34 / 90  Retrospective evaluation of the association between hyponatremia and neurological dysfunction in hospitalized foals (2012-2016): 109 cases Objective: Hyponatremia and rapid correction of hyponatremia can lead to neurological abnormalities. Retrospective cohort 109 foals