The patient is a 33-year-old male, an automobile factory worker with a bachelor's degree, who presented to cognitive impairment clinic on 15 September 2021 with the chief compliant of "memory declines for 3 years and progressive deterioration for 5 months". Three years before admission, the patient developed memory decline without obvious inducement, mainly in recent memory impairment. He was found to have reduced responsiveness during communication and sometimes was reluctant to communicate with others, occasionally incoherent, but he was still able to fulfill his job. His family noticed that he was emotionally indifferent, did not concerned about his family and family affairs as much as he had been in the past, and was emotionally depressed. Two years ago, the patient had visited the neurology outpatient department because of the above symptoms and underwent cranial magnetic resonance imaging (MRI) examination on 17 December 2019, which showed encephalomalacia in the right basal ganglia, frontal lobe and cerebral atrophy (Figures 1A-C). Five months ago, the patient felt that his memory loss was worsening, manifested by an inability to recall the events of the previous day, as well as to remember newly learned lyrics and melodies (he used to be good at music), and occasional transient difficulty typing on his mobile phones. Seven days prior to admission, the MRI (31 August 2021) results showed that the encephalomalacia foci had expanded to bilateral frontal lobe, right insula, and right temporo-occipital junction as compared to previous findings (Figures 1D-F). The pressure of cerebrospinal fluid (CSF) by lumbar puncture was normal, the CSF appearance was colorless and transparent, the routine examination was normal, and the biochemical and immune examinations were normal. His symptoms were not significantly improved after treatment with nutritional nerve and intellectual promotion, and he was later transferred to our cognitive impairment clinic and admitted to the neurology department. He had no significant medical history, denying arterial hypertension, diabetes, coronary heart disease (CHD), cerebrovascular disease, and other chronic diseases. Denied any history of infectious diseases such as hepatitis, tuberculosis and malaria; history of trauma and blood transfusion; history of food and drug allergy. He had been depressed after suffering an emotional trauma in 2011. A history of dog bite and rabies vaccination in 2018. Smoking history of 10 years, 20 cigarettes/day; no history of alcohol consumption. His uncle died and began to show signs of memory impairment at the age of 50. Denied any other family history of genetic problems. Physical examination: T 36.5 C, P 52 times/min, R 17 times/min, BP 127/87 mmHg (1 mmHg = 0.133 kPa), no deformity in the chest, lungs breath sounds clear, no wet and dry rales. The heart sounds were strong and rhythmic, and there were no pathological murmurs in the auscultation area of each valve. The abdomen was soft, without tenderness, and the liver and spleen cannot be palpable under the ribs. There was no swelling in the lower limbs, and no deformity of the spinal limbs. Neurological examination: clear in consciousness, fluent in language, time, place, character orientation are normal, calculation is normal, declined in recent memory, bilateral pupils equal in size, left: right for 3 mm:3 mm, pupillary light reflex was present, central eye position, ocular motility was normal, no diplopia or nystagmus, bilateral nasolabial sulcus were symmetrical, central tongue extension, soft palate elevation were normal, pharyngeal reflex (+), limbs muscle strength grade V, normal muscle tone, tendon reflex (++), bilateral Babinski sign (-), bilateral symmetric sensory examination, bilateral limbs ataxia examination were stable and accurate. The frontal lobe release signs of palm-grasping reflex, rooting reflex and sucking reflex were all negative.
The routine blood, coagulation function, serum immune function, liver and kidney function, lipids, blood glucose, high sensitive C-reactive protein, homocysteine, thyroid function, folic acid, vitamin B12, ferritin, immune panel (hepatitis A, hepatitis B, hepatitis C, syphilis and HIV), urine routine and stool routine showed no significant abnormalities. The electrocardiogram showed sinus rhythm and normal. No arrhythmias were detected by ambulatory electrocardiography (AECG). Cardiac color doppler ultrasound showed mild regurgitation of aortic valve, mitral valve and tricuspid valve. No intracardiac right-to-left shunts was detected by right heart contrast echocardiography. Color doppler ultrasound of abdomen and urinary system showed no abnormalities. Brain MRI (22 September 2021) results showed punctate hyperintensity on diffusion-weighted imaging (DWI) of the right cerebellum, suggesting an acute cerebral infarction, cerebral atrophy and encephalomalacia foci in different degree (Figure 1G). Brain magnetic resonance angiography (MRA) (22 September 2021) showed no significant abnormalities in the vascular morphology and structure (data not shown). The neuropsychological assessment showed multidomain cognitive decline, highlighted by delayed recall deficits, as well as emotional apathy and sleep disturbances (Table 1). The Dr. Brain tool was used to automatically perform brain tissue segmentation and extract multiparameter volumetric measurements of different brain regions for analysis (https://cloud.drbrain.net, registration number: 20212210359). The artificial intelligence brain structure imaging analysis showed that the proportion of gray matter and white matter to intracranial volume decreased, and the proportion of bilateral thalamus, caudate nucleus, putamen, bilateral frontal lobe, parietal lobe, occipital lobe, and temporal lobe decreased, especially reduced in the cerebellum regions (Table 2).