Neurologic Assessment and Critical Care of Exotic Animals: Approach to the Neurologic Exam, Species Differences, Prognostic Scales, Commonly Encountered Conditions, Ancillary Diagnostic Tests, and Caring for Neurologically Impaired Patients.

Many disorders of other body systems have been well characterized in exotic species; however, data regarding neurologic conditions is limited. Across some of these species, correlates between feline and canine neurology can be made, but variations in the nervous system anatomy make evaluation more challenging. With accurate neurolocalization a focused list of differential diagnoses can be created. Performing the neurologic examination should be methodical for all patients, and the order and extent of examination may depend upon the patient's clinical condition and cooperation. Applications of objective scale measures (such as coma scales), and ancillary diagnostics (electrodiagnostics, advanced imaging, biopsy techniques, and BAER testing) complement physical assessment and clinicopathologic assessment in these neurologic patients. Once a neurolocalization, likely diagnosis, and prognosis have been established, specific considerations for hospitalization and care of neurologic patients can be implemented while treatment is instituted.

Assessment of Orthopedic Versus Neurologic Causes of Gait Change in Dogs and Cats.

Diagnosis of forelimb lameness may be challenging, as it not only can be due to multiple common orthopedic diseases but also may occasionally be caused by neurologic disease. A thorough orthopedic and neurologic examination is key to determining which disease category is the likely culprit. Deficits identified on the neurologic examination, such as proprioceptive deficits, changes in reflexes, and presence of spinal hyperesthesia, are key in identifying neurologic causes of forelimb lameness.

Assessment of the cutaneous trunci muscle reflex in neurologically abnormal cats.

OBJECTIVES: The aim of this study was to evaluate the presence of the cutaneous trunci reflex (CTR) in a population of neurologically abnormal cats in regard to age, body condition score (BCS), sex, breed, evidence of traumatic injury, pain, known metabolic disease, mentation, neurolocalization and diagnostic classification. METHODS: A retrospective medical record review was performed to identify cats with a history of neurologic disease undergoing a complete neurologic assessment between 24 September 2012 and 20 March 2019. CTR outcome (present, absent), signalment, evidence of traumatic injury, pain, known metabolic disease, mentation, neurolocalization and diagnostic classification were recorded. RESULTS: A total of 182 cats were identified. The CTR was present in 118 cats (64.8%) and absent in 64 cats (35.2%). Statistical analysis revealed no association between CTR outcome and age, BCS, sex, breed, evidence of traumatic injury, non-spinal pain, known metabolic disease, mentation, neurolocalization or diagnostic classification. A significant association was found between spinal pain and CTR outcome (P = 0.037). CONCLUSIONS AND RELEVANCE: These findings suggest that elicitation of the CTR in the cat can be unreliable. Further prospective controlled studies are warranted to determine whether continued inclusion of the CTR in feline neurologic examinations is justified. Consideration of the reliability of the CTR is indicated, particularly in the context of fractious or anxious patients for which only a limited window for examination may be present.

Assessment of menace response in neurologically and ophthalmologically healthy cats.

OBJECTIVES: Assessment and interpretation of menace response (MeR) in cats can be challenging. The prevalence of abnormal MeR in healthy cats is unknown. The aim of this study was to prospectively evaluate MeR in visually healthy cats. METHODS: Fifty cats without history or clinical evidence of neurological or ophthalmological disease were assessed by two examiners: standing behind the cat (mode A), in front of the cat (mode B), and in front of the cat, covering the contralateral eye (mode C). MeR was scored from 1-5 (absent, weak, moderate, strong, complete). Examination modes were compared concerning presence and score (descriptive statistic, 95% confidence interval, χ2 test). This was compared to a three-level scoring system (negative, reduced, positive). Score reproducibility between the two examiners was assessed (Cohen's kappa [κ] test). Video footage allowed self-re-evaluation and evaluation of the second examiner (κ analysis). Learning/tiring effect (McNemar test), influence of age, body weight (Spearman's rho test), skull type (χ2 test) and being an indoor or outdoor cat (Mann-Whitney U-test) were evaluated. RESULTS: MeR was always elicited with at least one technique. Comparable results were obtained with the five- and three-level scoring systems. Mode A achieved strong/complete (positive) MeR in 84.5%, mode B in 82% and mode C in 60%. Exact score reproducibility between the two examiners was slight to fair (κ = 0.208-0.281). Intrarater agreement for video self-assessment (κ = 0.544-0.639), as well as inter-rater agreement (extrinsic video assessment), was moderate to substantial (κ = 0.584-0.645). No learning/tiring effect ( P = 0.530) or association with body weight ( P = 0.897), age ( P = 0.724), skull type ( P >0.05) and being an indoor/outdoor cat ( P = 0.511) were evident. CONCLUSIONS AND RELEVANCE: The majority of visually healthy cats revealed a strong/complete MeR when the contralateral eye remained uncovered, but 40% failed when the contralateral eye was covered. The most reliable examination mode was achieved standing behind the cat.

Head trauma in the cat: 1. assessment and management of craniofacial injury.

PRACTICAL RELEVANCE: Feline trauma is commonly seen in general practice and frequently involves damage to the head. CLINICAL CHALLENGES: While craniofacial injuries following trauma vary widely in severity, affected cats can often be severely compromised in terms of their neurological, respiratory and cardiovascular status, and their management can be challenging in both the short and long term. They need prompt stabilisation and careful monitoring in the initial period to maximise prospects of a successful outcome. Many cats with severe facial trauma will require surgery to stabilise skull fractures or address injuries to the eyes, with its inherent issues surrounding pain management, ensuring adequate nutrition and the necessity for ongoing hospitalisation. DIAGNOSTICS: Cats with head trauma benefit from imaging of the injured areas as well as thoracic radiography. Imaging the skull can be challenging and is best performed under general anaesthesia. In unstable patients this can be delayed to prevent any associated morbidity. EVIDENCE BASE: The clinical evidence base relating to injury to the feline head is limited, despite its relative frequency in general practice. This review focuses on the initial approach to craniofacial (in particular, ocular and jaw) trauma, and outlines simple techniques for management of soft tissue and bone injuries. Much of the information is based on the authors' clinical experience, as there is a paucity of well-described clinical case material.

Head trauma in the cat: 2. assessment and management of traumatic brain injury.

PRACTICAL RELEVANCE: Feline trauma patients are commonly seen in general practice and frequently have sustained some degree of brain injury. CLINICAL CHALLENGES: Cats with traumatic brain injuries may have a variety of clinical signs, ranging from minor neurological deficits to life-threatening neurological impairment. Appropriate management depends on prompt and accurate patient assessment, and an understanding of the pathophysiology of brain injury. The most important consideration in managing these patients is maintenance of cerebral perfusion and oxygenation. For cats with severe head injury requiring decompressive surgery, early intervention is critical. EVIDENCE BASE: There is a limited clinical evidence base to support the treatment of traumatic brain injury in cats, despite its relative frequency in general practice. Appropriate therapy is, therefore, controversial in veterinary medicine and mostly based on experimental studies or human head trauma studies. This review, which sets out to describe the specific approach to diagnosis and management of traumatic brain injury in cats, draws on the current evidence, as far as it exists, as well as the authors' clinical experience.

Investigations of the reliability of observational gait analysis for the assessment of lameness in horses.

The objectives of this study were to assess the reliability of a numerical rating scale (NRS) and a verbal rating scale (VRS) for the assessment of lameness in horses and to determine whether they can be used interchangeably. Sixteen independent observers graded the severity of lameness in 20 videotaped horses, and the agreement between and within observers, correlation and bias were determined for each scale. The observers agreed with each other in 56 per cent of the observations with the NRS and in 60 per cent of the observations with the VRS, and the associated Kendall coefficient of concordance was high. Similar trends were evident in the agreement between two observations by each observer. The correlation between and within observers was high for both scales. There were no significant differences (bias) among the observers' mean scores when using either scale. There was a significant correlation between the lameness scores attributed when using the two scales, but the differences between the scores when plotted against their overall mean were unacceptable for clinical purposes. The results indicate that the NRS and VRS are only moderately reliable when used to assess lameness severity in the horse, and that they should not be used interchangeably.

Assessment and treatment of central nervous system abnormalities in the emergency patient.

Disease of or injury to the central nervous system is a common rea-son for hospital admission on an emergency basis in veterinary medicine. Head injuries, seizures, and diseases that lead to intra-cranial hypertension frequently result in significant alteration of neurologic function. A thorough understanding of the pathophysiologic disturbances that occur during these conditions is para-mount for providing stabilizing emergent care. A detailed approach that focuses on meticulous physical evaluation, provision of timely and optimal stabilizing treatment, and continued monitoring can aid in improving outcomes in animals with signs and symptoms of neurologic disease or injury.

Initial assessment of patients with neurologic dysfunction.

This article describes a practical approach to the initial assessment of patients with neurologic dysfunction. First, the patient's clinical signs are determined by obtaining a medical history and performing an examination. Based on these results, the disease is localized to a particular region of the nervous system. Analysis of the neuroanatomic diagnosis in conjunction with the history is used to establish a list of differential diagnoses. The clinician then recommends appropriate laboratory tests to confirm or exclude the diagnostic possibilities. By following a logical process of clinical reasoning, the practitioner is often able to deduce a clinical diagnosis and prognosis and offer recommendations for treatment.

Assessment of the nervous system.

This article describes the examination of the neurologic and ophthalmic systems in ruminants. Neuroanatomy with respect to lesion localization is reviewed. Pertinent age and species differences are addressed. The practical aspects of assessing the neurologic system are stressed, and the reader is directed to other sources of information for assistance in determining the differential diagnosis and therapy of neurologic disease.

Oral levodopa dose-response study in MPTP-induced hemiparkinsonian monkeys: assessment with a new rating scale for monkey parkinsonism.

Quantitative measures for the severity of MPTP-induced parkinsonism and response to antiparkinsonian interventions in monkeys have been lacking. We carried out an oral levodopa dose-response study in two rhesus monkeys whose left hemiparkinsonism was induced by intracarotid administration of MPTP. A newly developed clinical rating scale of monkey parkinsonism showed a consistent dose-response relationship for levodopa over the dosage range of 50-3,500 mg/day. Antiparkinsonian effects appeared at 200 mg/day and were optimal at 1,000-2,000 mg/day. Levodopa also reversed rotational behavior, improved movement times for both the impaired and opposite upper limb, and produced dyskinesias at high dosages. Thus, MPTP-induced hemiparkinsonism in monkeys closely resembles the human disease condition, is associated with sensitive response measures, and should prove valuable for assessing novel antiparkinsonian therapies.