Frontotemporal lobar degeneration (FTLD), clinically known as frontotemporal dementia (FTD), is a group of dementia syndromes characterized by progressive mental and behavioral abnormalities, executive dysfunction, and language impairment. Selective frontal and/or temporal lobe atrophy.The etiology of FTLD has not been clearly defined, and it is clinically, pathologically, and genetically heterogeneous. There are not many global epidemiologic studies on FTLD, and there are no epidemiologic data on FTLD in China. Data from Western countries show that the age of onset of FTLD is 40-80 years, with the most common onset occurring at 45-64 years. The incidence rate of FTLD in Europe and America is (2.7-4.0)/100,000 people per year. In people aged 45-64 years, the prevalence is (15-22)/100,000 people. FTLD is one of the leading causes of early-onset dementia and is the 3rd leading cause of dementia caused by neurodegeneration, after Alzheimer’s disease (AD) and dementia with Lewy bodies. The prevalence of FTLD is comparable in men and women, and the average survival of patients with FTLD ranges from 6.6 to 11.0 years. Early diagnosis and early intervention can significantly improve the prognosis of FTLD patients, but the diagnosis and treatment rates of dementia patients vary greatly between different cities and regions in China. Improving the identification, diagnosis, and treatment of FTLD by clinicians is a core factor in early diagnosis and treatment and overall management. This expert consensus mainly refers to the guidelines of the EuropeanFederation of the Neurological Societies, the criteria published by the International Behavioral VariantFTD Criteria Consortium, and the criteria for the diagnosis and treatment of FTLD published by the International Federation of Neurological Societies (IFNS). Consortium, and relevant literature published by the American Academy of Neurology to systematically describe the clinical typing, diagnosis, evaluation and management of FTLD, with a view to providing guidance to clinicians. Common clinical subtypes and diagnostic criteria The main pathological feature of FTLD is limited frontotemporal lobar atrophy. Early studies named these cases Pick’s disease, which means that patients may have Pick’s vesicles and Pick’s cells, and in the late 20th century, it was found that many patients with frontotemporal lobar atrophy did not have typical Pick’s vesicles in their brain pathology, and thus they were renamed as non-AD frontal lobe dementia or frontal lobe dementia, and were uniformly referred to as FTD in the clinical diagnostic criteria published in 1994. The criteria were revised again in 1998, which included the following subtypes: FTD, progressive nonfluent aphasia, and progressive nonfluent aphasia. In 1998, the criteria were revised again, and FTD, progressive non-fluent aphasia (PNFA), and semantic dementia (SD) were united as FTLD, which is a group of syndromes characterized by progressive psychobehavioral abnormalities, executive dysfunction, and/or language impairment. According to clinical features, FTLD is currently classified into three main clinical subtypes: behavioral variant frontotemporal dementia (bvFTD), SD, and PNFA, of which SD and PNFA can be classified as primary progressive aphasia (PPA). progressive aphasia (PPA). In addition, clinically, pathologically and genetically, FTLD can exist in combination with progressive supranuclear palsy (PSP) and neurodegenerative movement disorders such as corticobasal ganglia syndrome (CBS) or related motor neuron disease (MND)/amyotrophic lateral sclerosis (ALS), which can be considered as specific subtypes of FTLD. Recent histopathologic and genetic studies have provided a broader understanding of FTLD. The neuropathology of FTLD consists of 3 main subtypes: microtubule-associated protein-tau protein (FTLD-TAU) type, TAR DNA-binding protein 43 (FTLD-TDP) type, and FUS protein (FTLD-FUS) type. In addition, there are 2 rare neuropathologic subtypes, a tau protein, TDP-43, and FUS protein-negative but ubiquitin-positive inclusion body subtype named FTLD-UPS and an indistinguishable inclusion body subtype named FTLD-ni. It was shown that the FTLD-TDP pathologic subtype was significantly correlated with the FTLD-MND and SD clinical phenotypes, and the FTLD -TAU pathologic subtype was significantly associated with PSP and CBS clinical typing, and the pathologic subtypes of bvFTD included TDP-43 (approximately 50%), TAU (approximately 40%), FUS, and others (approximately 10%). In terms of genetics, although the majority of FTLD cases are disseminated, there are a few (10%-20%) familial aggregates that exhibit autosomal dominant inheritance. Several genetic variants associated with FTLD have been demonstrated, such as microtubule-associated protein-tau (MAPT), granulin precursor (PGRN), TARDNA-binding protein 43 (TARDBP), valine casein-containing protein (VCP), dynamin-activating protein 1 (DCTNI), sarcomeric fusion protein (FUS), and charged multivesicular body protein 2B ( CHMP2B) gene variants and the recently identified C90RF72 hexanucleotide repeat amplification. It has been shown that FTLD neuropathologic typing is associated with specific genetic mutations, with the FTLD-TAU subtype associated with mutations in the MAPT gene, the FTLD-TDP subtype associated with mutations in the TARDBP, PGRN, and VCP genes, the FTLD-FUS subtype associated with mutations in the FUS gene, and the FTLD-UPS subtype associated with mutations in the CHMP2B gene. (1) bvFTD bvFTD is a clinical syndrome characterized by progressive deterioration of personality, social behavior, and cognitive function, accounting for about 50% of FTLD, and the most pathologically heterogeneous and heritable subtype of FTLD. Clinical manifestations include progressively worsening behavioral abnormalities, decreased interpersonal and/or executive abilities, with deficits in emotional responses, and autonomic hyperalgesia. The most significant behavioral abnormalities include disinhibition, motivational deficits, obsessive-compulsive behaviors, ritualistic behaviors, stereotyped movements, and hyperarousal. bvFTD is variable, with a wide range of clinical manifestations in different patients. Studies have found that early-onset bvFTD is associated with FTLD-FUS, and the correlation between typical bvFTD and pathologic subtypes is unclear. bvFTD clinical manifestations may be correlated with its pathologic subtypes, and studies have suggested that patients with affective response deficits are associated with the FTLD-TDP Type1 GRN phenotype. bvFTD relies primarily on clinical diagnosis, and there is a lack of clear biomarkers. The diagnostic criteria of the International bvFTD Criteria Consortium are shown in Table 1. (2) PPA PPA has an insidious onset and is characterized by significant language deficits in the early stages (Table 2), highlighted by progressively worsening deficits in speech production, naming, utterance organization, or word comprehension. Aphasia is the most prominent cognitive impairment in the early stages of the disease as well as on physical examination, after which other cognitive functions can be involved [. It usually does not affect other daily living functions except for language-related functions (e.g., making phone calls). The diagnostic criteria for PPA are: 3 of the following must be positive: the most prominent clinical feature is language impairment; there is impairment of relevant daily living functions caused by language impairment; and aphasia is the most significant cognitive impairment at the time of symptom onset and early in the course of the disease. and all 4 of the following were negative: other non-neurological degenerative or medical disorders better explaining the cognitive impairment; psychiatric disorders better explaining the cognitive impairment; significant situational memory, visual memory, or visual perceptual deficits early in the course of the disease; and significant behavioral deficits early in the course of the disease. PPA includes 3 subtypes: SD, PNFA, and logopenic type progressive aphasia. Among them, SD and PNFA belong to FTLD (see Tables 2 and 3 for diagnostic criteria), and logopenic progressive aphasia is not categorized as FTLD because its pathological changes are more inclined to AD-like changes, and its clinical manifestations are mainly characterized by difficulties in word extraction in spontaneous speech and impaired ability to repeat utterances and phrases, with brain atrophy mainly affecting the inferior parietal lobe and temporal lobe. ①SD: SD, also known as semantic variant PPA, is a syndrome with more consistent clinical manifestations. It is typically characterized by progressive fluent aphasia, in which patients present with severe loss of naming, impaired comprehension of spoken and written words, fluent but empty speech, and lack of vocabulary, accompanied by superficial dyslexia (the ability to read words according to their pronunciation, but not to read words with irregular spelling) and dysgraphia. Impaired visual information processing (prosopagnosia and object prosopagnosia) occurs in severe and advanced cases, and more extensive impairment of nonverbal functioning can occur. The pathogenesis of SD is associated with selective, asymmetric anterior-inferior temporal lobe atrophy, with predominant involvement of the temporal lobe of the left dominant hemisphere (left-sided type), whereas patients presenting with nonverbal semantic deficits have predominant involvement of the temporal lobe of the right dominant hemisphere. The right-sided type of SD is less common than the left-sided type of SD, and patients present mainly with impaired situational memory, vagueness, and behavioral abnormalities such as personality changes, loss of empathy, and obsessive-compulsive behaviors, with less common verbal deficits, and semantic memory deficits limited to people, tastes, or food, such as prosopagnosia. In patients with SD with an onset of more than 3 years, the clinical symptoms of the left-sided and right-sided types gradually begin to overlap: patients with the left-sided type begin to show behavioral symptoms, and patients with the right-sided type also develop extensive semantic and language deficits.SD is mainly associated with the FTLD-TDP pathotype, which is positive for TDP-43 protein in 75% of the patients, and a minority of the patients may also have other pathologies, such as tauopoietinopathies.Diagnostic of SD The criteria are shown in Table 2. ② PNFA: PNFA, also known as nonfluent/grammatically incorrect variant of PPA, patients present with progressive nonfluent spontaneous speech disorders, including grammatical disorders characterized by incorrect use or omission of grammatical words, articulation-based phonological disorders, and naming aphasia. Pathological manifestations are mostly cortical atrophy around the anterolateral fissure of the left hemisphere brain (anterior type).70% of PNFA are significantly associated with the FTD-TAU pathotype.Diagnostic criteria for PNFA are shown in Table 3.Table 1 International Diagnostic Criteria for bvFTD Diagnostic Criteria Ⅰ Neurological Degenerative Disease Progressive deterioration in behavioral and/or cognitive functioning must be present to meet the criteria for hvFTD Ⅱ Suspected bvFTD must be present with at least 3 of the following behavioral/cognitive manifestations (A-F) that are persistent or recurrent rather than a single or rare eventA Early disinhibition [presence of at least 1 of the following symptoms (A1-3)]a:A1 Inappropriate social behaviorsA2 Lack of courtesy or sense of social dignityA3 Impulsivity Recklessness or carelessnessB Early onset of indifference and/or retardationaC Early onset of lack of sympathy/empathy [at least 1 of the following symptoms (C1-2) is present]a:C1 Lack of responsiveness to the needs and feelings of othersC2 Lack of interest, interpersonal relationships, or personal feelingsD Early onset of persistent/compulsive/stereotypic behaviors [at least 1 of the following symptoms (D1-3) is present]a:D1 Simple, repetitive actionsD2 Complex compulsive/stereotypic behaviorsD3 Stereotypic Language E Hyperphagia and altered eating habits [presence of at least 1 of the following symptoms (E1-3)]: E1 Altered eating preferences E2 Overeating, increased intake of tobacco and alcohol E3 Omnivorexia F Neuropsychological manifestations: executive dysfunction combined with relatively mild memory and visual dysfunction [presence of at least 1 of the following symptoms (FI-3)]: F1 Executive dysfunction F2 Relatively mild situational memory Impairment F3 Relatively mild visual dysfunction III Possible bvFTD All of the following symptoms (A-C) must be present to meet the criteria A Criteria for suspected bvFTD are met B Impairment of life or social functioning (caregiver evidence, or evidence of Clinical Dementia Rating Scale or Functional Activity Questionnaire scores) C Imaging manifestations are consistent with bvFTD [presence of at least 1 of the following (C1 -2)]: C1 CT or MRI demonstrating frontal and/or anterior temporal lobe atrophy C2 PET or SPECT demonstrating frontal and/or anterior temporal lobe hypoperfusion or hypometabolism IV Pathologic confirmation of a diagnosis of bvFTD must be present in accordance with 1 of the following A criteria versus B or C: A Histopathologic evidence of frontal-temporal lobe degeneration consistent with a suspected bvFTD or probable bvFTDB biopsy or cadaveric histologic examination C Presence of a known disease-causing gene mutation V Exclusion criteria for bvFTD All 3 of the following (A-C) must be negative for a diagnosis of bvFTD; C may be positive for a diagnosis of suspected bvFTD A Symptoms are more likely to be caused by other neurologic non-degenerative or medical disorders B Behavioral abnormalities are more consistent with a psychiatric diagnosis C Biomarkers are strongly suggestive of Alzheimer’s disease or other neurodegenerative lesions Note: a As a general guideline, “early” means within 3 years of symptom onset; bvFTD: behavioral variant frontotemporal lobe dementia (3) FTLD-related disorders combined with neurodegenerative movement disorders Table 2 Diagnostic Criteria for SD Diagnostic Criteria Ⅰ Clinical Diagnosis of SD The following core features must be present: 1. Naming disorder 2. Impaired vocabulary comprehension Must have at least 3 of the following other diagnostic features: 1. Impaired semantic knowledge of objects (particularly noticeable with low frequency or low familiarity items) 2. Superficial dyslexia or dysgraphia 3. Preserved repetition 4. Preserved speech production (grammatical or oral) Ⅱ Diagnosis of SD supported by imaging findings Must have both of the following core features: 1. Clinical diagnosis of SD 2. Imaging Examination showing at least one of the following findings: a. Significant anterior temporal lobe atrophy b. Significant anterior temporal lobe hypoperfusion or hypometabolism as demonstrated by SPECT or PET Ⅲ SD supported by definitive pathologic evidence shall meet 1 as well as 2 or 3 of the following: 1. Clinical diagnosis of SD 2. Pathohistologic evidence of a specific neurodegenerative lesion (e.g., FTLD-TAU, FTLD-TDP, Alzheimer’s disease or other associated pathologic changes) 3. Presence of a known pathogenic gene mutation Note: SD: semantic dementia; FTLD-TAU: frontotemporal lobar degeneration-microtubule-associated protein-tau protein; FTLD-TDP: frontotemporal lobar degeneration-TAR DNA-binding protein.43, Table 3 Same as Table 3 Diagnostic criteria for PNFA Diagnostic Criteria Ⅰ Clinical diagnosis of PNFA Clinical diagnosis of PNFA With at least one of the following core features. Grammatical deficits in speech production 2. labored, intermittent speech with inconsistent phonological errors and distortions (dysarthria) At least 2 or more of the following other features: 1. impaired comprehension of grammatically complex sentences 2. retention of vocabulary comprehension 3. retention of semantic knowledge of objects Ⅱ Diagnosis of PNFA supported by imaging tests. 1. consistent with the clinical diagnosis of PNFA 2. Imaging studies must have at least 1 or more of the following: a. MRI showing significant left posterior frontal and insular atrophy b. SPECT or PET showing significant left posterior frontal and insular hypoperfusion or hypometabolism Ⅲ PNFA with definitive evidence of pathology Shall have 1 of the following as well as 2 or 3 1. Pathohistologic evidence of a specific neurodegenerative lesion (e.g., FTLD-TAU, FTLD-TDP, Alzheimer’s disease, or other relevant pathological changes) 3. Presence of a known causative gene mutation Note: PNFA: Progressive Nonfluent Aphasia ①PSP: PSP is a clinical syndrome caused by tauopoietinopathy, manifested by Parkinson’s-like syndrome, vertical gaze disorders, postural instability, and dementia. PSP: PSP is a clinical syndrome caused by tau protein lesions that manifests as Parkinson-like syndrome, vertical gaze disorders, postural instability, and dementia, with 40% of patients exhibiting symmetrical limb loss. The National Institute of Neurological Disorders and Stroke has published clinical diagnostic criteria for PSP. Most patients lose their ability to care for themselves within 3-4 years of diagnosis. Frontal lobe executive dysfunction occurs earlier and is more common in patients with PSP, with severe impairments in nonverbal reasoning and verbal fluency, and more pronounced impairments in verbal fluency than in semantic fluency; memory function is usually only mildly impaired, with impaired free recall, but recollective memory remains normal; personality changes and behavioral abnormalities are often varied; PSP is significantly correlated with the FTLD-TAU pathology subtype. PSP is significantly associated with FTLD-TAU pathology. CBS: CBS has a progressive course with asymmetric ankylosis, bradykinesia, or dyskinesia. Postural and locomotor tremor, abnormal limb muscle tone, localized reflex myoclonus, postural instability, seizures of falls, alien hand syndrome, pyramidal fasciculations, ocular/eyelid dyskinesia, and dysarthria may occur in more than half of the patients during the course of the disease. Most patients develop dementia in the late stages of the disease.CBS is also significantly associated with the FTLD-TAU pathologic subtype. CBS is also significantly associated with the FTLD-TAU pathotype. iii) FTLD-MND: About 10%-15% of FTLD patients have concomitant ALS, and C90RF72 gene-related FTLD is characterized by ALS, a chronic progressive neurodegenerative disease characterized by selective loss of upper and lower motor neurons, and clinically manifested by atrophy and weakness of medullary innervated muscles, limbs, and trunk muscles, and even respiratory muscle paralysis. The non-coding GGGGCC hexanucleotide repeat amplification in the C90RF72 gene is significantly associated with whether or not FTLD/ALS family members develop the disease. Recent studies have shown that mutations in the C90RF72 gene correlate with the imaging phenotype of frontal lobe atrophy (with anterior temporal lobe, parietal lobe, and cerebellar involvement.) FTLD-MND is primarily associated with the FTLD-TDP pathologic subtype. 3.Clinical assessment Accurate diagnosis is a prerequisite for clinical management and optimal prognosis (Figure 1). It should begin with a careful history, and clinicians should focus on the patient’s mental behavior, cognitive function and language function. (1) General clinical data collection History taking should focus on the patient’s impaired cognitive domains, the stage of the disease, impaired ability to perform daily living tasks, and disease-related noncognitive symptoms. In addition, information on past history, comorbidities and family history, and educational background are also important. A systematic neurological examination is very important in distinguishing FTLD from other types of dementia. (2) Assessment of cognitive domains The assessment of cognitive functioning in patients with FTLD may address the domains of executive functioning, attention, language, social-cognitive functioning (including mental behavior), learning memory, and visual-spatial awareness. As a neurologist, it is important to understand and master some common assessment scales used for initial screening of FTLD, such as the Simple Intelligent Mental State Assessment Scale, the Frontal Lobe Assessment Test, and the Cambridge Cognitive Function Assessment Scale. Physicians engaged in the clinical diagnosis of cognitive disorders must also know the common tests used in different cognitive domains, such as the Stroop Color Word Test and the Connection Test for the assessment of executive function; the Boston Naming Test and the Fluency Test for the assessment of language function; and the Auditory Word Learning Test and the Visual Regeneration Test for the situational memory test. The Neuropsychiatric Symptom Scale, Frontal Behavioral Scale, and Frontal Behavioral Score were used to assess psychobehavioral symptoms. The Neuropsychiatric Symptom Inventory is a commonly used assessment tool in most clinical studies, but evidence suggests that the Neuropsychiatric Symptom Inventory score is not effective in reflecting significant changes in clinical symptoms of FTLD, while the Frontal Lobe Behavioral Scale is more sensitive and effective in the assessment of FTLD. A recent study on the application of neuropsychological tests to discriminate between patients with FTLD and AD showed that the progressive application of the Word Lifting Fluency Test, the Boston Naming Test, and the Delayed Recall Test was effective in discriminating between FTLD and AD, with a sensitivity of 64% in the diagnosis of FTLD, and a specificity and precision of 95.5% and 88.6%, respectively . At the same time, this study showed that neuropsychological tests could not identify FTLD-TAU and FTLD-ubiquitin (belonging to the FTLP-TDP), which are the two pathologic subtypes of FTLD. Physicians engaged in FTLD research should also be aware of and, if possible, have knowledge of the following neuropsychological battery of tests (refer to Alzheimer’s Disease International for information): the Benson Complex Picture Imitation and Delayed Recall, the Phonological Fluency Test, the (Regular/Irregular) Vocabulary Reading Test, the Semantic Vocabulary-Picture Matching Test, the Semantic Correlation Test, the Northwestern Crossword Puzzle Test (Short Form), and the Repeated Sentence Test, Noun and Verb Naming Test, Reading Sentence Test, and the Social Norms Questionnaire, Social Behavior Observation Scale, Behavioral Inhibition Scale, Interpersonal Reactivity Index, and Revised Self-Monitoring Scale. (3) Neuroimaging assessment Frontal and temporal lobe atrophy is a typical imaging manifestation of FTLD and is supporting evidence for the diagnosis of FTLD. However, the lack of these manifestations does not exclude FTLD. bvFTLD patients have an asymmetric distribution of right frontal and temporal lobe atrophy, whereas PPA is characterized by asymmetric atrophy of the left temporo-occipital lobe. bvSD patients have atrophy limited to the left temporal pole in the early stages, and with progression of the disease, it can involve the right temporal pole, left frontal lobe, and parietal cortex. cvFTLD patients have atrophy in the right temporal pole, left frontal lobe, and left frontal lobe. Single photon emission computed tomography (SPECT) brain perfusion imaging of 99mTc HM-PAO distribution and fluorodeoxyglucose-positron emission tomography (FDC-PET) imaging reflect local metabolic activity and cerebral blood flow. Hypoperfusion and hypometabolism are often manifested in cerebrovascular lesions and cerebral degenerative lesions. The use of three-dimensional stereoscopic analysis can improve the sensitivity and specificity of diagnosis. SPECT and PET perfusion and metabolic imaging technology also has considerable application value in the diagnosis of FTLD, the sensitivity of its identification of typical lesion area is more than 90%, and the high specificity of clinical diagnosis can improve the accuracy of diagnosis, and can be used to identify different FTLD language variations. Currently, molecular imaging techniques such as Pittsburgh complex B, which are commonly used in clinical practice, are not pathologically characteristic in brain imaging of FTLD patients, and most FTLD patients do not have Pittsburgh complex B retention. These techniques can also be used to identify language variants in different FTLDs. Recent studies have shown that magnetic resonance diffusion tensor imaging (DTI) is helpful in identifying AD and FTLD (both diagnosed by cerebrospinal fluid biologic markers or autopsy). In addition, a case-control study showed that alterations in white and gray matter DTI diffusion coefficients could identify different types of FTLD: bvFTD patients had increased mean diffusivity of gray matter in the frontal and temporal lobes bilaterally, with loss of gray matter and abnormal diffusion coefficients of the white matter bundles connecting these regions; SD patients had loss of gray matter in the temporal lobes of the left dominant hemisphere, with increased mean diffusivity and abnormal diffusion coefficients of the inferior longitudinal fasciculus and the hook bundle ; gray matter loss and increased mean diffusivity in the left inferior frontal lobe, insula, and supplementary motor areas, and abnormal diffusion coefficients in the superior longitudinal fasciculus were found in patients with PNFA. 4. Patient management (1) Pharmacological treatment No drugs have been approved by the U.S. Food and Drug Administration for the treatment of FTLD. pharmacological treatment of FTLD is mainly symptomatic for behavioral, motor and cognitive deficits, etc. Many drugs that are widely used for the treatment of other types of dementia are also available. Many drugs that are widely used to treat other types of dementia and neurodegenerative diseases are often used in the symptomatic treatment of FTLD, and their efficacy is variable. Commonly used drugs include selective 5-hydroxytryptamine reuptake inhibitors, atypical antipsychotics, N-methyl-D-aspartate receptor antagonists, and cholinesterase inhibitors (ChEIs). The frontal cortex is rich in 5-hydroxytryptamine, and the clinical features of 5-hydroxytryptamine dysfunction include depression, aggression, and impulsivity similar to the behavioral symptoms of clinical FTLD. Several open studies and clinical evidence suggest that 5-hydroxytryptamine reuptake inhibitors (e.g., fluvoxamine, sertraline, and paroxetine) may ameliorate behavioral symptoms in patients with FTLD, e.g., they may reduce disinhibition, impulsivity, repetitive behaviors, and eating disorders. However, another small-sample randomized placebo-controlled trial found that paroxetine (40 mg) did not improve behavioral symptoms in FTLD and exacerbated cognitive deficits, the latter of which may be related to the anticholinergic effects of high doses of paroxetine. Small doses of atypical antipsychotics (e.g., risperidone, aripiprazole, and olanzapine) improve psychobehavioral symptoms of FTLD, such as disruptive or aggressive behaviors, but cause adverse effects, such as drowsiness, weight gain, and extrapyramidal symptoms. Furthermore, the use of these drugs in older patients increases the rate of death secondary to heart disease and infections and should therefore be used with caution. In view of the evidence of abnormalities in the glutamate transporter system in the brain of patients with FTLD, N-methyl-D-aspartate receptor antagonists (e.g., memantine) may be used in the treatment of FTLD, and a series of in vitro and in vivo studies have demonstrated their ability to reduce the pathologic hyperphosphorylation of tau proteins, which suggests that they may be efficacious in FTLD. It has been shown in a series of in vitro and in vivo studies that it can reduce the pathologic hyperphosphorylation of tau protein, suggesting that it may be effective in FTLD. At the same time, several studies have confirmed that memantine can improve the psychiatric symptoms of FTLD patients, and the scores of frontal behavioral scale and neuropsychiatric symptom scale improved after taking the drug, and the improvement of three subitems of indifference, agitation, and anxiety was particularly obvious, and the safety and tolerability of the treatment were good; moreover, the administration of memantine can increase the metabolism of bilateral insulas and the left orbital frontal cortex in patients with FTLD, and this metabolism increased at the end of 6 months, and the metabolism increased at the end of 6 months. metabolic increase was maintained at the end of 6 months. In another multicenter, randomized, double-blind, placebo-controlled study that included 81 patients with FTLD treated with memantine and placebo for 26 weeks, the primary efficacy measure, the NPI score, showed a short-term improvement in the memantine group (6 weeks, P=0.01), but there was no difference between the two groups at the end of the study. The small sample size and the design of this study, which did not utilize an FTLD-specific assessment scale, limit the interpretation of the results and make it difficult to draw reliable conclusions. Overall, therefore, previous clinical reports and open studies of memantine in the treatment of FTLD have confirmed its therapeutic efficacy and good tolerability, thus supporting its possible use in the treatment of patients with FTLD. In addition, because of the absence of abnormalities in the cholinergic transmitter system in the brain of patients with FTLD, current clinical studies have not found evidence that ChEls are effective in FTLD, and that they may lead to worsening of psychiatric symptoms, especially disinhibition and obsessive-compulsive behaviors. Therefore, the British Psychopharmacological Society did not recommend ChEIs for the treatment of FTLD in its 2011 guidelines. (2) Non-pharmacological treatments Pharmacological treatments cannot completely eliminate the negative behavioral symptoms of patients with FTLD, so non-pharmacological therapies, such as behavioral, physical, and environmental improvement strategies, need to be used in conjunction with pharmacological treatments.Aggression, disinhibition, and dyskinesia in patients with FTLD make the patient risk of injury to themselves and their caregivers, and therefore require individualized safety improvement measures tailored to the specific needs of the patient. Regular aerobic exercise strengthens neural connectivity networks, provides neuroprotection, and slows cognitive decline in neurodegenerative diseases. The physical and mental health of the FTLD caregiver is also very important. Due to significant behavioral deficits and self-awareness deficits and the young age of onset, caregivers of patients with FTLD often face a heavy emotional, financial, and physical burden. Both depression and stress are more common and the overall burden is higher among caregivers of people with FTLD than people with AD, and caregivers should be given more education and support in the necessary ways.