# A LeViT-EfficientNet-Based Feature Fusion Alzheimer's Disease Diagnosis
## 1 Introduction  
According to the World Health Organization, the total number of individuals aged 60 and older is expected to double by 2050, reaching approximately 2.1 billion people, 22% of the global population [1]. Alzheimer's disease (AD) is a neurodegenerative condition that primarily affects the elderly population [2]. However, it may manifest in younger individuals. It is the primary cause of dementia. Mild cognitive impairment may occur in the initial stages of AD [2]; this is a transitional stage from normal functioning to AD in which an individual has moderate cognitive abnormalities [3]. The individuals may experience difficulties in performing their routine tasks [4]. They may face challenges in remembering recent events, names, and conversations. In addition, they may exhibit agitation and aggression. With an anticipated increase in AD cases, the disease has become one of the significant global concerns of the modern era. Despite massive efforts to find a cure, AD is still a non-preventable and irreversible form of dementia that impairs an individual's daily life [5]. It is complicated and progressive, necessitating early discovery, diagnosis, therapy, and family support [6]. As the condition progresses, AD patients increasingly rely on their caretakers and require assistance with routine activities. The primary etiology of AD remains unclear. However, genetics, environment, and lifestyle may contribute to AD [6]. Medical treatment and assistance can place a financial burden on individuals with AD and their families. Globally, governments, healthcareorganizations, and research institutes are focusing on the development of practical approaches to address the challenges associated with AD [6]. Researchers investigate AD's backgrounds, risk factors, prevention, and therapy to identify successful strategies to reduce its progression. Most cases of dementia are based on neurodegeneration caused by AD. Increasing evidence from neuropathological and neuroimaging studies shows that mixed etiologies cause many dementia cases, especially in people over 80 years [7]. There has been more variation in the findings regarding the prevalence of dementia and AD in populations older than 90 years compared to younger populations [7]. Healthy aging, dementia care, and caregiver assistance are being applied to improve AD patients' quality of life [8]. Cognitive tests and assessments investigate memory, attention, language, reasoning, and problem-solving [8]. The Mini-Mental State Examination, Montreal Cognitive Assessment, and AD Assessment Scale-Cognitive Subscale are frequently used for AD detection [8]. Cognitive function may be assessed in greater detail with neuropsychological tests [9]. These tests demonstrate cognitive strengths and limitations and may distinguish AD from distinct dementias [10]. Lumbar puncture may collect cerebrospinal fluid from the lower back [11; 12; 13; 14]. Elevated beta-amyloid and tau proteins in cerebrospinal fluid may indicate AD pathology. In a few instances, genetic testing may be utilized to diagnose AD, particularly among individuals with a family history of AD [15]. An in-depth neuropsychological evaluation is a crucial diagnostic component in the diagnosis of dementia [16]. It analyzes magnetic resonance imaging (MRI) scans for signs of regional brain atrophy and determines the AD biomarkers using the cerebrospinal fluid biomarker profile. It evaluates individuals' memory, attention, language, and emotional performance. Healthcare practitioners' subjective interpretation of cognitive and neuropsychological testing can result in diagnostic discrepancies [16; 17; 18]. Several imaging modalities may reveal the brain's structure and function, highlighting abnormalities associated with AD [18]. The diagnosis of AD relies on a wide variety of biomarkers, including genetic and biological data and neuroimaging techniques, MRI, amyloid positron emission tomography (PET), and diffusion tensor imaging [19; 20; 21].