臨床推理應用於中老年犬隻以區分犬認知障礙症候群與其他前腦疾病

Abstract

犬認知障礙症候群（Canine Cognitive Dysfunction Syndrome, CCDS）是好發於 老年犬隻的神經退化性疾病，由於其特徵性臨床症狀“行為改變”亦可能發生於 其他影響前腦之疾病，臨床診斷常需依賴高階影像診斷工具來排除其他疾病。然 而臨床實務中，可能受到飼主財務負擔、老年犬麻醉風險及飼主之主觀認知等因 素影響，而無法進行完整的診斷流程。本研究旨在評估是否有特定的臨床特徵與 CCDS 或其他影響前腦之疾病相關，進而找出預測因子，以協助計畫診斷流程時之 臨床推理和輔助飼主溝通。

本研究回朔分析 2019 年 11 月至 2024 年 1 月期間，在國立臺灣大學附設動物 醫院接受磁振造影腦部檢查、年紀大於七歲以上，且表現前腦相關神經症狀之 263 隻犬隻之醫療紀錄，研究內容包含病患基本資料、症狀進程表現、神經學檢查相 關發現及其臨床診斷。罹患 CCDS 之犬隻分別與其他非 CCDS 犬隻、具有進展性 病程之犬隻、診斷為腦瘤之犬隻，及診斷為腦炎之犬隻，進行統計比較分析。所 有臨床變因首先進行單變量分析，並保留相關性達統計意義趨勢（p < 0.3）之因子， 進一步納入多變項邏輯斯迴歸分析，以識別出與 CCDS 顯著相關之臨床因子。

統計結果顯示，相較於其他前腦疾病，年齡較大（OR = 2.114, 95% CI = 1.47 – 3.04）、無癲癇發作（OR = 10.98, 95% CI = 2.32 – 52.63）及無神經功能缺損偏向性之犬隻（OR = 7.46, 95% CI = 1.32 – 41.66），更可能被診斷為犬認知障礙症候群；近一步與具進展性病程的非 CCDS 組比較時，發現慢性病程中出現急性惡化（OR = 0.019, 95% CI = 0.001 – 0.27）、神經功能缺損具偏向性（OR = 0.079, 95% CI = 0.009 – 0.724）以及病灶定位為前腦合併腦幹（OR = 0.013, 95% CI = 0.0 – 0.41）等特徵，皆與具進展性病程但非 CCDS 之其他腦病較為相關。與個別疾病進行比較 後發現，癲癇發作（OR = 0.083 95% CI = 0.013 – 0.541）、在慢性病程中出現急性惡化（OR = 0.123, 95% CI = 0.020 – 0.763）較常與腦部腫瘤有關；若出現神經功能缺損偏向性（OR = 0.032, 95% CI = 0.002 – 0.629）則較與發炎性疾病相關。本研究結果顯示，特定的臨床表現與神經學檢查特徵，有助於臨床獸醫師在面對前腦症狀之中老年犬隻時，進行更精確的鑑別診斷與臨床決策。

Canine cognitive dysfunction syndrome (CCDS) is a common neurodegenerative disease in aging dogs, as its characteristic clinical sign “behavioral changes” can also occur in other diseases affecting the forebrain, advanced diagnostic tools are often required to establish the clinical diagnosis. However, factors such as financial constraints, anesthetic risks in geriatric dogs, and owner assumptions about CCDS often hinder a complete diagnostic workup. The purpose of the study was to evaluate whether specific clinical features are associated with CCDS or other forebrain diseases, aiming to identify predictors that can aid clinical reasoning and facilitate communication with pet owners.

This retrospective study reviewed the medical records of 263 dogs over seven years of age that underwent magnetic resonance imaging (MRI) for forebrain-related neurological signs at the National Taiwan University Veterinary Hospital between November 2019 and January 2024. Clinical data including signalment, disease presentation, neurological examination findings, and final diagnosis were collected and analyzed. Dogs diagnosed with canine cognitive dysfunction syndrome (CCDS) were statistically compared with non-CCDS dogs, non-CCDS dogs with progressive disease course, dogs diagnosed with brain neoplasia, and dogs with encephalitis. All clinical variables were initially assessed using univariate analysis, and variables loosely associated (p < 0.3) were included in a multivariable logistic regression model to identify factors significantly associated with CCDS (p < 0.05).

The results showed that dogs with older age (OR = 2.114, 95% CI = 1.47–3.04), absence of seizures (OR = 10.98, 95% CI = 2.32–52.63), and absence of lateralized neurological deficits (OR = 7.46, 95% CI = 1.32–41.66) were more likely to be diagnosed with CCDS than with other forebrain diseases. When compared specifically with non-CCDS dogs with a progressive disease course, features such as a recent deterioration in chronic disease course (OR = 0.019, 95% CI = 0.001–0.27), lateralized neurological deficits (OR = 0.079, 95% CI = 0.009–0.724), and a forebrain together with brainstem lesion localization (OR = 0.013, 95% CI = 0.0–0.41) were significantly associated with non-CCDS conditions. When specific diagnoses were compared with CCDS, the presence of seizure (OR = 0.083, 95% CI = 0.013–0.541) and a recent deterioration in chronic disease course (OR = 0.123, 95% CI = 0.020–0.763) were more commonly associated with brain neoplasia, while lateralized neurological deficits (OR = 0.032, 95% CI = 0.002–0.629) were indicative of encephalitis.

These findings suggest that distinct clinical and neurological features may assist veterinary clinicians in making a more accurate differential diagnosis and clinical decision when managing aging dogs presenting with forebrain signs.