Jang Yoo,Miju Cheon,Min-Ju Kang
A Case Report of Early-Onset Alzheimer’s Disease Using 18F-FDG PET and 18F-FBB PET
early-onset Alzheimer’s disease,18F-FDG PET,18F-florbetaben PET,case report
We describe a 40-year-old female patient who presented with sleep disturbance, intermittent headache, and gradual subjective cognitive decline. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) showed mild FDG hypometabolism in bilateral parietal and temporal lobes. However, 18F-florbetaben (FBB) amyloid PET revealed diffuse amyloid retention in the lateral temporal cortex, frontal cortex, posterior cingulate cortex/precuneus, parietal cortex, and cerebellum. This finding supports the clinical significance of amyloid imaging in diagnostic work-up of early-onset Alzheimer’s disease (EOAD).
A Case Report of Early-Onset Alzheimer’s Disease Using 18F-FDG PET and 18F-FBB PET

We describe a 40-year-old female patient who presented with sleep disturbance, intermittent headache, and gradual subjective cognitive decline. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) showed mild FDG hypometabolism in bilateral parietal and temporal lobes. However, 18F-florbetaben (FBB) amyloid PET revealed diffuse amyloid retention in the lateral temporal cortex, frontal cortex, posterior cingulate cortex/precuneus, parietal cortex, and cerebellum. This finding supports the clinical significance of amyloid imaging in diagnostic work-up of early-onset Alzheimer’s disease (EOAD).

A 40-year-old female patient visited an outpatient clinic complaining of sleep disturbance, intermittent headache, and gradual subjective cognitive decline, which had started two years earlier and progressed in the past year. Working as a ballet dancer, she often repeated the mistake of forgetting dance motions, which made her quit the job and put her in a stressful situation. Her sleep disturbance and headache were not reported every time, but these symptoms occasionally appeared in stressful situations. Her mother was diagnosed with Alzheimer’s disease (AD) when she was in her 30s. There was no other past medical history. Her laboratory results, including a complete blood count, electrolytes, glucose, lipid profiles, and a thyroid function test, did not reveal any abnormalities. Her Apolipoprotein E genotyping was reported as E3/E3. Physical examination also revealed no abnormalities. A neuropsychological test battery was implemented to evaluate the patient’s cognitive status. She scored 21 on the mini-mental status examination (MMSE) and 0.5 on the clinical dementia rating scale (CDR) on the first time visit to our clinic, which suspected amnestic mild cognitive dementia. This report is one of the few cases of early-onset Alzheimer’s disease (EOAD) by 18F-FDG and 18F-FBB PET images (Figure 1 and Figure 2). Although this patient demonstrated the early onset of cognitive decline, it was uncertain to determine the EOAD only through 18F-FDG PET. However, it seemed reasonable to evaluate EOAD through 18F-FBB PET. Amyloid imaging has been recommended in patients with (1) early (below 65 years of age) onset of progressive dementia; (2) atypical or mixed presentation of AD; and (3) persistent or progressive unexplained mild cognitive impairment [4]. Considering her symptoms presented at an atypically early age, amyloid PET imaging was appropriately performed to investigate the etiology of her cognitive decline. It is considered that the possibility of autosomal dominant AD is more likely from her clinical history [5]. Consistent with the amyloid cascade hypothesis, it can be assumed that amyloid deposition preceded glucose hypometabolism or structural atrophy in autosomal dominant AD [6]. We focus on the additive significance of amyloid PET imaging to determine the clinical diagnosis in uncertain dementia cases even after the assessment of neurodegeneration by 18F-FDG PET [7,8]. Although the genotype test was lacking in this case, this report aims to help the physician determine the differential diagnosis of autosomal dominant EOAD by amyloid PET imaging. Therefore, it is important to perform amyloid PET imaging in patients with early-onset cognitive decline to optimize the management, emphasizing the implementation of clinical practice.