Abstract
Objectives
The aim of this study was to evaluate whether clinical variables from the history, clinical presentation, and physical and neurological examinations of cats with vestibular syndrome were statistically predictive of the underlying diagnosis.
Methods
In total, 174 cats presenting with vestibular syndrome between January 2010 and May 2019 were investigated. Univariate statistical analysis of clinical variables was performed and those statistically associated with a diagnosis were retained for multivariable binary logistic regression modelling.
Results
The seven most prevalent diagnoses represented 95% of vestibular presentations, which included: otitis media/interna (n = 48), idiopathic vestibular syndrome (n = 39), intracranial neoplasia (n = 24), middle ear polyp (n = 17), feline infectious peritonitis (n = 13), thiamine deficiency (n = 13) and intracranial empyema (n = 11). Idiopathic vestibular syndrome was commonly associated with non-purebred cats and had 17.8 times the odds of an improving clinical progression (95% confidence interval [CI] 1.3–250.0; P = 0.03). Intracranial neoplasia was associated with older age and chronic onset of clinical signs, and was significantly more likely to have a central vestibular neuroanatomical localisation (95% CI 8.5–344,349,142.0; P = 0.015) with postural deficits on neurological examination. Thiamine deficiency was more common in female cats, with 52.6 times the odds of a waxing and waning clinical progression (95% CI 1.2–1000; P = 0.038) and 6.8 times the odds of presenting with bilateral vestibular signs (95% CI 1.0–45.7; P = 0.047) and wide excursions of the head (95% CI 1.0–45.7; P = 0.047). Middle ear polyps were associated with 8.8 times the odds of presenting with Horner syndrome (95% CI 1.5–50.0; P = 0.015).
Conclusions and relevance
Although it may be difficult to identify the underlying diagnosis in cats with vestibular syndrome from the presenting features alone, there are instances in which discrete clinical features may help to guide clinical reasoning when evaluating cats with vestibular presentations.
Introduction
Neurological disorders are a common reason for referral in veterinary practice, with a reported prevalence of 10% of feline cases in one referral population. 1 Vestibular syndrome is frequently encountered in feline neurology and can result from dysfunction of any part within the vestibular system. Clinical signs of unilateral vestibular dysfunction include the presence of a head tilt, pathological nystagmus, positional strabismus and gait abnormalities manifesting as ataxia, circling, leaning or falling. 2 Vestibular disorders are commonly asymmetrical or unilateral in presentation; however, bilateral disease can occur and is characterised by wide bilateral excursions of the head, typically with generalised vestibular ataxia, crouched posture and falling to both sides. 3 While the clinical signs of vestibular syndrome can be readily identified from clinical and neurological examination, they are not specific to the underlying diagnosis. In such circumstances, adopting a clinical reasoning-based approach can aid the clinician in forming a prioritised list of differential diagnoses and hence establishing diagnostic and treatment plans for the patient.
The vestibular system is functionally divided into peripheral and central components, with the neurological examination forming the primary means of differentiating peripheral and central vestibular syndrome. 4 While the neurological examination is frequently reliable at establishing a neuroanatomical localisation, the absence of clinical signs such as abnormal mentation, postural or cranial nerve deficits, does not always preclude the presence of central vestibular syndrome.5,6 Accurate neuroanatomical localisation can aid the clinician in formulating a prioritised list of differential diagnoses, determining a diagnostic plan and prognostication, with causes of central vestibular syndrome having been attributed, in referral hospital populations, with a poorer prognosis than peripheral disease.5,7 Idiopathic vestibular syndrome and otitis media/interna are widely regarded as the most frequent causes of peripheral vestibular syndrome in cats,3,6,8,9 with neoplastic lesions of the middle ear also reported.10,11 Central vestibular syndrome has been reported secondary to intracranial neoplasia, 5 feline infectious peritonitis (FIP),12,13 ischaemic infarcts,14,15 thiamine deficiency16–18 and intracranial empyema. 19
Clinical reasoning encompasses the decision-making process in which the clinician integrates clinical variables and factors to determine the most appropriate differential diagnoses, diagnostic tests and treatment for the patient.20,21 An important aspect of clinical reasoning in cases of vestibular syndrome involves the neurological assessment of the patient to identify signs consistent with central nervous system involvement, thereby localising the presentation as a central or peripheral vestibular disease. 5 Previous studies have demonstrated the potential application of clinical reasoning in neurological patients, by identifying statistical associations between clinical variables and the underlying diagnosis in presentations of canine and feline epilepsy, cervical hyperaesthesia and spinal disorders.22–25 However, it is unknown whether such a statistical model can be translated for clinical reasoning in cases of vestibular syndrome.
The aim of this study was to evaluate whether discrete clinical parameters from the history, presentation, physical and neurological examination, including the neuroanatomical localisation, of cats presenting with vestibular syndrome could be used to statistically predict the most likely differential diagnoses. It was hypothesised that statistical models could be used to identify associations between discrete clinical variables and common causes of vestibular syndrome in cats. The resultant statistically supported associations could be integrated as part of a clinical reasoning approach by veterinary surgeons when evaluating cats with vestibular syndrome.
Materials and methods
Ethical approval for this retrospective study was granted by the Royal Veterinary College (RVC) Social Sciences Research Ethical Review Board (SR2019-0436).
The digital medical database of the Small Animal Referral Hospital, RVC, was searched to retrieve the records of all cats presenting for further investigation of vestibular syndrome between 1 January 2010 and 1 May 2019. Cats were required to have undergone a general physical examination and complete neurological examination with appropriate further diagnostics to obtain a definitive or presumptive diagnosis. All neurological examinations were performed by a board-certified neurologist or a neurology resident under the direct supervision of a board-certified neurologist. Cases with incomplete medical records and imaging studies, or those in which a clinical or presumptive diagnosis was not reached, were excluded from the study. Cases were grouped according to the diagnosis determined by the attending board-certified neurologist. Diagnoses with five or fewer cases, such as ischaemic infarct, congenital hydrocephalus and non-infectious inflammatory central nervous system (CNS) disease were grouped as ‘other’ for inclusion in statistical analysis.
The diagnostics performed were decided on an individual case basis by the attending board-certified neurologist and included CT, MRI, cerebrospinal fluid (CSF) analysis, blood tests including haematology, biochemistry and infectious disease testing, cytology or histopathology if indicated. CT was performed with a 16-slice helical scanner (PQ 500, Universal Systems, Solon; GE Healthcare) under sedation or general anaesthesia. MRI was performed with a high-field unit (1.5 T, Intera; Phillips Medical Systems) under general anaesthesia and included a minimum of T2- and T1-weighted images in sagittal and transverse planes along with fluid attenuation inversion recovery and gradient echo transverse images. All MRI, CT and radiographic studies were reviewed by a board-certified neurologist.
For the purpose of this study, a diagnosis of FIP was reached based on previously reported MRI changes, in addition to detection of feline coronavirus by real-time reverse transcriptase PCR on CSF or, when performed, post-mortem histopathology of haematoxylin and eosin stained sections of the fourth ventricle and mesencephalic aqueduct.12,13,26 Otitis media/interna was diagnosed when compatible changes, affecting the middle and inner ear, were identified on MRI or CT imaging and further supported by otoscopy and myringotomy when performed.9,19,27 A middle ear polyp diagnosis was considered when advanced imaging demonstrated a pedunculated, well-demarcated, soft tissue mass in the region of the nasopharynx.10,11,28,29 Intracranial empyema was diagnosed based on the combination of compatible MRI findings and CSF abnormalities.30–32 A diagnosis of thiamine deficiency was considered based upon the presence of previously described MRI changes or evidence of a decreased thiamine blood level;16,33,34 the diagnosis was further supported with a clinical response to appropriate treatment. A diagnosis of idiopathic vestibular syndrome was made by exclusion and therefore only considered when no diagnostic testing abnormalities were evident, which was required to include MRI.4,5,8,35 Diagnostic criteria for the MRI characterisation of intracranial neoplasia,36–38 ischaemic infarcts14,15,39 and congenital hydrocephalus 40 were used in making a radiological diagnosis of these conditions.
For all cases within the study population, the following information was collected from medical records: signalment, including age, breed, sex, weight and neuter status; clinical history, including onset, duration of clinical signs, disease progression, and general physical and neurological examination changes; and findings from diagnostic investigations, including blood tests and advanced imaging. Statistical analysis for the majority of breeds was limited by small sample sizes; therefore, breed was categorised as purebred or non-purebred for analysis. Onset of clinical signs was categorised into peracute (<2 days), acute (2–10 days) and chronic (>10 days). Progression of clinical signs was categorised into improving, stable, waxing and waning, or progressive, based upon the clinical history from the referring veterinary surgeon and owner.
Neurological deficits were termed lateralised when the board-certified neurologist deemed there to be an unequivocal difference in the severity of clinical signs between the left and right sides of the cat. This included evidence of asymmetry associated with a head tilt or postural deficits when identified. Evidence of bilateral vestibular signs or paradoxical vestibular syndrome were recorded when present. Bilateral vestibular signs were defined by observing a wide-based, crouched posture, oscillating head movements and the absence of a head tilt.4,5 Paradoxical vestibular syndrome, corresponding to involvement of the flocculonodular lobe of the cerebellum or caudal cerebellar peduncle, was characterised by evidence of postural deficits with a contralateral head tilt. 4 Gait was categorised as normal, ataxic, ataxic with paresis or hypermetric. In instances where a nystagmus was present, this was further categorised as horizontal, vertical or rotatory, according to the predominant direction of the fast phase. Evidence of Horner syndrome, characterised by miosis, enophthalmos, protrusion of the third eyelid and ptosis was recorded when present. 41 In addition, evidence of a facial neuropathy, characterised by paresis of the muscles of facial expression and deficits of the menace response and palpebral reflex, were noted when present. 2 Neuroanatomical localisation was categorised as peripheral vestibular or central vestibular based upon the presence or absence of clinical signs of central involvement on neurological examination. Signs associated with central involvement on neurological examination included mentation changes, postural deficits and deficits associated with multiple cranial nerves (other than cranial nerves VII, VIII and sympathetic innervation to the eye). 3
Statistical analysis was performed using statistical software (SPSS version 25.0.0.1; IBM). Univariate analysis of all clinical variables was performed for each diagnosis. Clinical variables loosely associated (P <0.30) with each diagnosis were retained and a logistic regression, using the forced entry method, was performed for each of the most prevalent diseases. The remainder of the study population not diagnosed with the disease being investigated, formed the control population. Variables retained in the final models were considered significant with a P value <0.05. 42 A false discovery rate for multiple comparisons was performed on the resultant P values. 43 Results are presented with odds ratios (ORs) and 95% confidence intervals (CIs) for each condition, compared with the rest of the study population (controls were those not diagnosed with the condition being modelled). 42 Non-normally distributed continuous data are presented as median (range), while normally distributed data are presented as mean ± SD.
Results
In total, 189 cats were presented for further investigation of vestibular syndrome during the study period. Fifteen were excluded owing to incomplete clinical records or a diagnosis not being reached. Altogether, 174 cats were therefore included in the study. The study population consisted of 92 males (87 neutered) and 82 females (77 neutered). The age of these cats ranged between 3 months and 16 years, while their weight ranged from 1 kg to 8.9 kg. The most commonly diagnosed condition was otitis media/interna (n = 48), followed by idiopathic vestibular syndrome (n = 39), intracranial neoplasia (n = 24), middle ear polyp (n = 17), FIP (n = 13), thiamine deficiency (n = 13) and intracranial empyema (n = 11). Of the remaining cats, four were diagnosed with ischaemic infarcts, three were diagnosed with congenital hydrocephalus, one was diagnosed with non-infectious inflammatory CNS disease and another was diagnosed with cranial cervical spinal neoplasia (Table 1). Histopathological confirmation of middle ear polyps was available in 15 cases (88%) following surgical removal. A diagnosis of intracranial neoplasia was confirmed by histopathology following surgical excision or post-mortem examination in two and four cases, respectively.
Summary of significant presentation, neurological examination and investigation findings for diagnoses with three or more cases
Data are n (%) unless otherwise indicated
OM = otitis media; OI = otitis interna; P = peracute; A = acute; C = chronic; I = improving; S = stable; Pr = progressive; W = waxing/waning; U = unilateral; B = bilateral; P = paradoxical; N = normal; BE = bilateral excursions; PV = peripheral vestibular; CV = central vestibular; FIP = feline infectious peritonitis
Breed
In total, 58% of cats within the study were non-purebred (n = 100), consisting of domestic shorthair (n = 90) and domestic longhair (n = 10). The most prevalent purebred cats were British Shorthair (n = 12), Siamese (n = 9), Burmese (n = 8) and Maine Coon (n = 7). Breed was significantly associated with idiopathic vestibular syndrome, which was more likely in non-purebred cats (Table 2).
Logistical regression analysis of presentation and neurological examination characteristics of leading diagnoses with 10 or more cases
Where statistically significant (P ⩽0.05), data presented include odds ratios with 95% confidence intervals indicated in parentheses and the comparison group for categorical data. Characteristics with no statistically significant bias are indicated with ‘–’
OE = otitis externa; OM = otitis media; OI = otitis interna; FIP = feline infectious peritonitis
Age
Age was significantly associated with a diagnosis of intracranial neoplasia, which was more likely in cats of older age (Table 2).
Weight
The weight of the patient was significantly associated with a diagnosis of intracranial empyema, with the diagnosis more likely in cats of lower weight (Table 2).
Sex
Sex was significantly associated with middle ear polyps and thiamine deficiency. Cats with a middle ear polyp were more likely to be male, whereas those diagnosed with thiamine deficiency were more likely to be female (Table 2).
Onset and progression of clinical signs
Onset of clinical signs was statistically associated with intracranial neoplasia, which was more likely have a chronic presentation. Progression of clinical signs was significantly associated with idiopathic vestibular syndrome and thiamine deficiency. Cats with idiopathic vestibular syndrome were more likely to follow an improving clinical course, whereas those diagnosed with thiamine deficiency were more likely to have a waxing and waning disease progression (Table 2).
Lateralisation of clinical signs
The absence of lateralised clinical signs was associated with thiamine deficiency, which was typically symmetrical in presentation (Table 2).
History of otitis externa
History of otitis externa was significantly associated with otitis media/interna and idiopathic vestibular syndrome. Cats diagnosed with otitis media/interna frequently had a history of previous otitis externa, while cats with idiopathic vestibular syndrome were significantly less likely to have a history of otitis externa (Table 2).
Postural deficits
The presence of postural deficits on neurological examination were significantly associated with intracranial neoplasia (Table 2).
Head tilt
The presence of bilateral excursions of the head rather than a lateralised head tilt was associated with a diagnosis of thiamine deficiency (Table 2).
Horner syndrome
Compared with other diagnoses, cats diagnosed with a middle ear polyp more frequently presented with Horner syndrome. Conversely, cats with idiopathic vestibular syndrome were significantly less likely to present with Horner syndrome (Table 2).
Neuroanatomical localisation
Neuroanatomical localisation was associated with a diagnosis of intracranial neoplasia, which was more likely to present with evidence of central involvement on examination (Table 2).
Discussion
The initial approach to formulating a prioritised list of differential diagnoses, and hence a diagnostic or empiric treatment plan, can be challenging for clinicians faced with presentations of vestibular syndrome in cats. Although clinical signs of vestibular dysfunctions such as a head tilt, vestibular ataxia and nystagmus can be readily identified on clinical examination, they are not specific to an underlying diagnosis. Applying a clinical reasoning-based approach, utilising clinical features from the history, and physical and neurological examination of the patient can help to clearly define and refine the presenting complaint. This approach aligns with the recent emphasis in veterinary medicine to utilise clinical information from the patient’s presentation in an evidence-based, problem-orientated manner to provide a structure for clinical decision-making.44,45 This can be particularly invaluable for inexperienced clinicians, complex or unusual presentations and instances in which financial or time constraints are present. The potential benefits of a clinical reasoning-based approach for neurological presentations has been previously documented in canine and feline spinal disease and epilepsy.22–25
Our results highlight instances in which discrete clinical characteristics obtained from the patient’s signalment, clinical history, and general physical and neurological examinations are statistically associated with some of the most common causes of feline vestibular syndrome. Although it is clear that the approach to neurological patients cannot be reduced to a simple algorithm, it is hoped that use of statistically validated clinical associations as a component of clinical reasoning can aid veterinary surgeons to improve the timeliness and accuracy of diagnosis in cats presenting with vestibular syndrome. Utilising statistical associations between clinical presentations and differential diagnoses should not be considered a substitute for performing confirmatory diagnostic tests, but rather as an adjunctive measure to aid the selection the most appropriate diagnostic approach for the presenting problem. Additionally, the study highlights the requirement of performing a complete neurological examination to identify the discrete clinical features associated with the most likely differential diagnosis.
Although a range of diagnoses were obtained within the study population, the seven most prevalent conditions represented 95% of vestibular presentations. The most common were otitis media/interna (28%) and idiopathic vestibular syndrome (22%), which is in agreement with the disease prevalence of a previous referral feline population. 6 However, it should be considered that the study population represents feline vestibular cases presented to a single referral hospital, and is therefore likely to be biased to more severe or complex clinical presentations, or conditions where specialist input is deemed necessary. This is further supported by a recent study evaluating canine vestibular disease in primary practice, which found that a significant proportion of cases (41.8%) improved within a median of 4 days, while only a small percentage (3.6%) of cases were referred for specialist evaluation and investigation. 46 Therefore, it must be considered that the prevalence of diseases, such as those associated with an improving clinical progression including idiopathic vestibular syndrome, may be underrepresented in referral populations when compared with first-opinion practice.
Otitis media/interna was one of the prevalent diagnoses, but only statistically associated with a history of previous otitis externa. The association of otitis media/interna with previous otitis externa is unsurprising given the anatomical proximity of the structures of the ear, and is consistent with reports of external ear changes in up to 30% of feline otitis media cases. 47 Conflicting research suggested that secondary extension of otitis externa occurs less commonly in cats than in dogs, with a reported association with nasal disease in the latter.48–50 It has been suggested that auditory tube obstruction secondary to mucosal inflammation due to upper respiratory tract disease and ascending bacterial infection via the auditory tube can predispose to otitis media without external ear involvement.50–52 Intracranial empyema is frequently reported in the literature occurring due to secondary extension of otitis media/interna.19,53 Therefore, shared clinical features between intracranial empyema and otitis media/interna could be responsible for the limited discrete clinical characteristics statistically associated with each diagnosis.
Middle ear polyps were associated with male cats and almost nine times the odds of presenting with Horner syndrome. The association of middle ear polyps with Horner syndrome is in agreement with the findings of previous studies and is unsurprising given the anatomical relationship between the structures of the middle ear and sympathetic innervation to the eye.2,54 The third-order neurons from the cranial cervical ganglion course through the tympanic bulla, and therefore disorders of this region, such as middle ear polyps, can result in signs of Horner syndrome. 2 This association is further supported by frequent reports of Horner syndrome occurring postoperatively following polyp removal using traction avulsion or ventral bulla osteotomy.55–57
Despite the same anatomical relationship, the association of Horner syndrome with middle ear polyps in the absence of an association with otitis media/interna is interesting and warrants further investigation. Reports of middle ear polyps causing secondary enlargement of the tympanic cavity, lysis of the adjacent petrous temporal bone, and a predilection to the septum and dorsolateral compartment of the tympanic bulla could explain the association with Horner syndrome.29,58 The association with sex is difficult to elucidate, with no predisposition reported in the current literature.54,56,59 Further investigation about the influence of sex on the development of middle ear polyps is therefore warranted.
Idiopathic vestibular syndrome was associated with 18 times the odds of having an improving clinical progression, non-purebred cats and without a history of previous otitis externa. This is consistent with previous literature, which classically describes idiopathic vestibular syndrome as an acute-onset condition with limited progression and improvement to normal status within 2–4 weeks. 35 This finding differs from an atypical subset of idiopathic vestibular syndrome reported within a retrospective study of 77 cats with vestibular syndrome, which presented with progressive clinical signs. 6 Idiopathic vestibular syndrome was associated with 26 times the odds of presenting without evidence of Horner syndrome, which is in agreement with previous reports that idiopathic vestibular syndrome is not associated with multifocal neurological signs. 5 A peripheral neuroanatomical localisation on examination is regarded as one of the hallmarks of idiopathic vestibular syndrome; however, there was no statistical association with localisation identified. 8 Despite the absence of a statistical significance, clinicians should consider the importance of a peripheral neuroanatomical localisation when presented with cases of potential idiopathic vestibular syndrome. Concurrent idiopathic vestibular syndrome and facial neuropathy is frequently identified in canine patients and previously reported in a cat; however, there was no statistically significant association between facial nerve deficits and any diagnosis identified within the study population.60,61 Although the identification of a head tilt or pathological nystagmus can readily alert the clinician to the presence of vestibular disease, interestingly, neither clinical sign was statistically associated with a specific underlying diagnosis.2,3,46
Thiamine deficiency was associated with bilateral vestibular signs characterised by wide bilateral excursions of the head. This is consistent with the findings of previous research with symmetrical presentations demonstrated in cases of nutritional disease. 17 Interestingly, cats diagnosed with thiamine deficiency were almost 11 times more likely to be female. This finding is consistent with a recently reported outbreak of thiamine deficiency in Taiwan, associated with dry food, in which 12/17 affected cats were female. 17 While there is evidence of a sex influence on the susceptibility to thiamine deficiency, the underlying biological reason for this predisposition is yet to be further explored. Thiamine deficiency was further associated with 53 times the odds of presenting with a waxing and waning clinical progression, which is consistent with the intermittent non-specific clinical signs, including anorexia, vomiting and lethargy, previously described in the early stages of disease. 17 The characteristic combination of clinical features associated with a diagnosis of thiamine deficiency could aid clinical reasoning, including the formulation of an appropriate diagnostic and treatment plan for these patients. This could be of particular importance for guiding treatment for cases in which the presenting features are highly suspicious for a diagnosis of thiamine deficiency; however, confirmatory diagnostics are limited by financial constraints.
Intracranial neoplasia was associated with older age and a chronic onset of clinical signs, which mirrors the typical onset and progression reported with neoplastic lesions.62,63 Furthermore, the diagnosis of intracranial neoplasia was also associated with a central vestibular neuroanatomical localisation, typically characterised by evidence of postural deficits on examination. This finding is consistent with previous literature and expected given the possible direct effect or secondary mass effect of intracranial tumours on the central components of the vestibular system.24,62
In the current study population, there were no statistically significant associations identified between a diagnosis of FIP and the clinical characteristics investigated. This is perhaps unexpected, given the associations between FIP, younger age and concurrent non-neurological clinical signs report in the literature.13,25 The absence of discrete clinical characteristics statistically associated with FIP could be the consequence of shared clinical features with other diagnoses in the study population. Middle-ear polyps are frequently reported in younger cats, while within the study population thiamine deficiency, intracranial empyema and otitis media/interna also presented in cats <1 year of age.54,56 Cats with intracranial empyema have been reported to present frequently with abnormal findings on general physical examination, which could have contributed to the absence of significance of this variable. 30 Alternatively, the lack of discrete clinical features could represent the natural variation in onset and progression of clinical presentations of FIP.12,13 The difficulty in reaching a reliable presumptive diagnosis of FIP from clinical reasoning characteristics is troubling. The condition is associated with a guarded prognosis, with limited readily available treatment options and therefore in an ideal situation this condition would be diagnosed promptly to prevent ongoing suffering.
Being retrospective in design, the diagnostic investigation of each patient within the study was not standardised and instead performed at the discretion of the attending board-certified neurologist. As a result, the investigations performed in reaching a diagnosis of exclusion, such as idiopathic vestibular syndrome, could be variable between cases. The study is limited by the inclusion of cases without histopathological confirmation of the diagnosis. This is of particular significance for cases of intracranial neoplasia and middle ear polyps, which rely upon histopathology to reach a confirmed diagnosis. Therefore, the possibility of incorrect classification of some these cases cannot be fully excluded. Although the diagnosis used within the study was confirmed by a board-certified neurologist and based upon published diagnostic criteria, it cannot be excluded that some patients may have been incorrectly classified.
All cases presented for vestibular syndrome within the study window that met the criteria were included, which meant that some conditions were represented in greater numbers than others. This approach meant that the least prevalent diagnoses could not be included within the statistical model, which inherently leads to bias of results to the most prevalent conditions. While less prevalent conditions such as ischaemic infarcts and congenital hydrocephalus could not be statistically analysed, they should still be considered by the clinician when presented with cases of vestibular syndrome. Alternatively, cases could have been selected to achieve equal numbers of each diagnosis; however, by using the true prevalence of diagnoses within the hospital population it is hoped that the resultant analysis is more likely to be representative of the proportions of disease within the population. Although variance in disease prevalence is statistically accounted for within the logistic regression model, it does mean that the less prevalent conditions may lack the statistical power of the most prevalent disorders and thus associations with the variables studied may have been missed. Furthermore, the analysis of each diagnosis against the remainder of the study population is not characteristic of real-life clinical scenarios, which runs the risk of some statistical associations being overstated. Although a statistically supported clinical reasoning-based approach can undoubtedly aid clinicians in identifying the most likely differential diagnosis for the most prevalent disorders, this approach is restricted when presented with unusual disease presentations or uncommon disorders and therefore these conditions remain difficult to identify in clinical practice.
Conclusions
With the innate variability of clinical presentations in veterinary medicine, the approach to diagnosing vestibular syndrome can never be reduced to a simple algorithm. Although it may be difficult to identify the underlying diagnosis in cats with vestibular syndrome from the presenting features alone, this study demonstrates that there are instances in which discrete clinical characteristics from the presentation of cats with vestibular syndrome can be used in an evidence-based approach to guide clinical reasoning and decision-making. It is hoped that this information can aid veterinary surgeons when evaluating cats with vestibular syndrome to improve the timeliness and accuracy of diagnosis.
Footnotes
Author note
The results of this study were presented in abstract form (poster presentation) at the 32nd symposium of the European Society of Veterinary Neurology – European College of Veterinary Neurology (ESVN-ECVN), 13–14 September 2019, Wroclaw, Poland.
Conflict of interest
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Ethical approval
This work involved the use of non-experimental animals only (owned or unowned), and followed established internationally recognised high standards (‘best practice’) of individual veterinary clinical patient care. Ethical approval from a committee was not necessarily required.
Informed consent
Informed consent (either verbal or written) was obtained from the owner or legal custodian of all animal(s) described in this work for the procedure(s) undertaken. No animals or humans are identifiable within this publication, and therefore additional informed consent for publication was not required.
