01OverviewDefinition, clinical context and the essential points that orientate the chapter.
FTD is a clinical syndrome caused by degeneration of frontal and temporal networks and heterogeneous protein pathologies, including tau and TDP-43 disease. Behavioural-variant FTD changes social conduct and motivation: tactless or impulsive acts, loss of warmth, inertia, rigid routines, repetitive movements, altered food preference and poor judgement may precede obvious memory failure. The language-led syndromes are progressive rather than stroke-like. Semantic-variant primary progressive aphasia causes fluent but empty speech, anomia and impaired single-word comprehension with loss of conceptual knowledge. Non-fluent or agrammatic PPA causes effortful, halting or grammatically simplified speech, sometimes with apraxia of speech. Logopenic PPA is commonly associated with Alzheimer pathology and should not automatically be classified as frontotemporal degeneration.
Diagnosis depends on change from the person's baseline and functional consequence. Seek collateral examples of work errors, online spending, scams, driving, eating, hygiene, sexual behaviour, empathy and language; distinguish apathy from depression by affect, distress, biological symptoms and loss of initiative. Screen medicines, alcohol, sleep, thyroid and B12 status, infection and structural disease. Formal neuropsychology can reveal executive, social-cognitive or language profiles despite a misleadingly acceptable global score. MRI assesses focal atrophy and alternative lesions; specialist functional imaging or cerebrospinal-fluid and Alzheimer biomarkers may resolve uncertain atypical cases. Psychiatric illness, autism traits, bipolar disorder and obsessive-compulsive disorder can mimic elements, but late progressive change, neurological features and worsening function require neurological evaluation.
Management is anticipatory and multidisciplinary. Speech and language therapy supports communication aids and swallowing; occupational therapy simplifies routines and risk; dietetic review addresses hyperorality, weight and dysphagia. Discuss driving, work, finances, internet access, lasting power of attorney and advance care while capacity remains for each decision. FTD can overlap with motor neurone disease, corticobasal syndrome or progressive supranuclear palsy, so review weakness, fasciculation, falls, eye movement and swallowing. Genetic assessment is especially relevant with young onset, multiple affected relatives, motor neurone disease or psychiatric-neurological clustering; C9orf72, MAPT and GRN are important causes, but testing has implications for unaffected relatives. Medication is symptomatic and secondary to environmental formulation. Cholinesterase inhibitors and memantine should not be offered for FTD under NICE guidance.
Key points
- Frontotemporal dementia often begins before 65 and presents with progressive personality, behaviour, executive or language change while episodic memory and visuospatial skills can be relatively preserved early.
- Behavioural-variant FTD features early disinhibition, apathy, loss of empathy, stereotyped or compulsive behaviour, hyperorality and executive dysfunction.
- Primary progressive aphasia may be semantic, with loss of word and object meaning, or non-fluent or agrammatic, with effortful speech and impaired grammar or speech planning.
- Obtain collateral history because reduced insight is common and a clinic conversation can underestimate home, financial, sexual, dietary or occupational consequences.
- MRI may show frontal or anterior temporal atrophy, often asymmetric, but diagnosis integrates progression, phenotype, cognitive testing and exclusion of mimics rather than a scan alone.
- Ask about motor neurone disease, parkinsonism and a three-generation family history; a substantial minority of FTD is genetic and counselling should precede predictive testing.
- NICE advises not offering acetylcholinesterase inhibitors or memantine for frontotemporal dementia because these Alzheimer medicines do not treat its core pathology.
- Non-drug care should adapt the environment, preserve routine, support communication, manage eating and risk, and protect carers from escalating burden.
- SSRIs or trazodone are sometimes used off label for selected behaviours, but evidence is limited; define a target, discuss uncertainty and stop when no meaningful benefit occurs.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Sporadic frontotemporal degeneration
Many cases arise without a recognised family history through progressive proteinopathy affecting frontal and anterior temporal networks, often before typical late-life dementia age.
Inherited proteinopathy
Pathogenic variants involving C9orf72, GRN, MAPT and other genes cause a substantial familial subgroup, with variable behavioural, language, parkinsonian or motor-neurone phenotypes.
Motor-neurone overlap
Shared TDP-related biology links some FTD syndromes with motor neurone disease, so weakness, fasciculation, bulbar change and respiratory symptoms require deliberate assessment.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Abnormal protein accumulation
Tau, TDP-related or less commonly FUS-related proteins misfold and disrupt neuronal and glial function in vulnerable networks.
- 2Frontal and temporal neuronal loss
Progressive synaptic failure and atrophy damage circuits governing inhibition, motivation, empathy, language meaning and speech planning.
- 3Network-level behavioural failure
Reduced executive control and social cognition produce disinhibition, apathy, compulsive behaviour or impaired language while episodic memory may remain superficially preserved early.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
Progressive disinhibition, apathy, reduced empathy, compulsive routines, dietary change and executive failure with early relative memory sparing forms the characteristic syndrome.
Fluent speech with severe naming and single-word comprehension difficulty, plus declining knowledge of familiar people or objects, suggests semantic-variant primary progressive aphasia.
Effortful speech, distorted sound production, apraxia of speech or grammatical simplification with initially preserved word meaning suggests non-fluent or agrammatic PPA.
Fasciculation, weakness, spasticity, dysphagia, parkinsonism, apraxia or impaired vertical eye movement may reveal overlap with motor neurone or atypical parkinsonian degeneration.
Several relatives with young dementia, motor neurone disease or late psychiatric change, or onset at a particularly young age, strengthens the case for genetics referral.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Collateral history and functional inventoryFirst step - Why
- Establish progressive change in social cognition, language, executive function and everyday risk beyond the clinic snapshot.
- Interpretation and limitations
- Specific longitudinal examples and loss of function carry more diagnostic weight than a family member simply describing the person as difficult.
- 02
Cognitive and neuropsychological assessment - Why
- Characterise executive, social-cognitive, semantic, grammar, speech-motor, memory and visuospatial domains.
- Interpretation and limitations
- A preserved brief global score does not exclude FTD; specialist testing can demonstrate selective network failure and distinguish a language syndrome.
- 03
MRI brain - Why
- Look for frontal or anterior temporal atrophy and exclude tumour, vascular, inflammatory or other structural disease.
- Interpretation and limitations
- Asymmetric focal atrophy supports a matching phenotype but can be subtle early; imaging must be interpreted in clinical and age context.
- 04
Reversible-cause blood assessment - Why
- Identify metabolic or systemic contributors to cognitive and behavioural change before final neurodegenerative attribution.
- Interpretation and limitations
- Use local dementia work-up including blood count, renal, liver, thyroid, B12 or folate and other history-led tests; an abnormality may coexist rather than explain all progression.
- 05
Specialist biomarkers or functional imaging - Why
- Clarify atypical disease or distinguish Alzheimer pathology when phenotype and MRI are inconclusive.
- Interpretation and limitations
- FDG-PET, perfusion imaging or CSF and amyloid biomarkers answer specialist questions; none should substitute for syndrome and function assessment.
- 06
Clinical genetics assessment - Why
- Evaluate inherited disease and support an informed choice about diagnostic or predictive genetic testing.
- Interpretation and limitations
- Test an affected person first where possible; counselling covers uncertain variants, insurance-relevant disclosure rules, family communication and the right not to know.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Primary psychiatric disorder
Depression, bipolar illness and psychosis can alter behaviour, but steadily progressive loss of empathy, executive function or language with neurological signs supports neurodegeneration.
Alzheimer disease
Early storage-memory and visuospatial failure favours Alzheimer disease; language-led or behavioural Alzheimer phenotypes still require biomarker-informed specialist distinction.
Structural frontal disease
Tumour, stroke, hydrocephalus and traumatic injury may mimic frontal degeneration, particularly with abrupt, stepwise or pressure-related symptoms and focal imaging findings.
Dementia with Lewy bodies
Visual hallucinations, marked fluctuation, REM sleep behaviour disorder and spontaneous parkinsonism point towards Lewy-body disease rather than classic FTD.
Additional chapter-specific clues
Hours-to-days change, impaired attention, altered consciousness, infection, medication toxicity or a new lesion indicates delirium or another emergency rather than uncomplicated neurodegeneration.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01RecognitionTurn behaviour into a neurological historyFirst stepPersonality, conduct or language has changed progressively in adult life.+
- 1Obtain private and joint collateral examples of timing, progression, empathy, inhibition, routines, eating, language, finances, driving and occupational performance.
- 2Assess attention, mood, psychosis, substance use, sleep and medicines, separating gradual network decline from delirium, primary psychiatric illness and situational conflict.
- 3Examine cognition, language, eye movements, parkinsonism and upper and lower motor neurone signs, and arrange standard blood and structural imaging assessment.
- 4Refer to a cognitive-neurology or young-onset dementia service for neuropsychology, biomarker decisions and a formulation shared with the family.
02Risk and supportAdapt the environment before sedating behaviourDisinhibition, apathy, compulsion, hyperorality or communication failure creates distress or risk.+
- 1Describe the exact antecedent, behaviour and consequence, then check pain, hunger, overstimulation, boredom, misunderstanding and carer interaction.
- 2Use predictable routines, simplified choices, supervised access to money or food, communication aids and meaningful activity matched to retained ability.
- 3Assess decision-specific capacity and use the least restrictive lawful safeguard for driving, finance, sex, internet, self-care or dependants.
- 4If a medicine is considered, define one measurable target, discuss weak evidence and adverse effects, review promptly and withdraw when ineffective.
03Future planningPrepare for progression and overlapFTD is diagnosed or strongly suspected and ongoing needs must be anticipated.+
- 1Coordinate speech, occupational, dietetic, community, social-care and carer assessments, including swallowing, nutrition and respite planning.
- 2PreferredDiscuss advance statements, lasting powers, benefits, employment and preferred care while the person can participate in each decision.
- 3Refer for genetic counselling when family pattern, age or motor overlap makes inherited disease plausible, respecting consent and relatives' autonomy.
- 4Monitor mobility, bulbar and respiratory symptoms and connect rapidly to motor-neurone or atypical-parkinsonism services if overlap emerges.
Key medicines and prescribing safety2 treatments · regimens, roles and cautions+
Selective serotonin reuptake inhibitor
If used off label, start the chosen SSRI at a low standard adult dose and titrate cautiously to a predefined behavioural target.Review hyponatraemia, bleeding, falls, activation and interactions; avoid using sedation as convenience, document uncertainty and stop when target behaviour does not improve.
Trazodone
Specialists may use a low evening dose and titrate within BNF limits when agitation or behavioural symptoms justify an off-label trial.Sedation, postural hypotension, falls, priapism and serotonergic interactions matter; an individual target and short review interval are essential.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Safeguarding and financial harm
Disinhibition, impaired judgement and loss of insight can lead to exploitation, unsafe driving, risky sexual behaviour, offending or catastrophic financial decisions.
Communication and nutritional failure
Progressive aphasia, hyperorality and later dysphagia impair consent, relationships, eating and aspiration safety as disease advances.
Motor-neurone and mobility complications
Coexisting motor neurone disease or parkinsonism can add weakness, falls, bulbar dysfunction and respiratory failure to cognitive disability.
Carer breakdown
Personality change, reduced empathy and repetitive behaviour create exceptional relationship and supervision burdens, often precipitating crisis placement or admission.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- Track specific behaviours, language function, nutrition, swallowing, falls and instrumental daily activities rather than relying on a global memory score.
- Review carer strain, sleep, safety and respite needs proactively because lack of patient insight can transfer a large hidden burden to relatives.
- Reassess driving, online and financial vulnerability, dependants and decision-specific capacity whenever function or household circumstances change.
- Monitor for fasciculation, weakness, spasticity, dysphagia, aspiration, parkinsonism and eye-movement abnormality suggesting a motor overlap syndrome.
- For any off-label psychotropic, record the target, baseline frequency, adverse effects and stop date, reviewing before repeat supply becomes automatic.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Memory can mislead
Early autobiographical recall may appear good while judgement, empathy and semantic knowledge collapse, so memory-led screens under-detect substantial disease.
Apathy is not simply depression
Loss of initiation without sadness, guilt or subjective distress can reflect frontal network failure; collateral observation helps distinguish overlapping syndromes.
Food behaviour localises
New sweet preference, rigid eating, food seeking or ingestion of non-food items can be a characteristic biological manifestation rather than deliberate misconduct.
Language labels imply pathology imperfectly
Clinical PPA variants identify affected networks, but underlying protein disease varies; logopenic presentations are often Alzheimer-related rather than frontotemporal.
Genetic information is shared information
A result may clarify one diagnosis while altering risk for siblings and children, making pre-test counselling and consent boundaries indispensable.
11Common pitfallsFrequent interpretation and management errors.
- 01
Diagnosing a primary personality or relationship problem from disinhibition or empathy loss without asking whether it is progressive and neurologically patterned.
- 02
Excluding FTD because a brief memory screen is acceptable while language, executive function and real-world judgement have deteriorated markedly.
- 03
Offering donepezil, rivastigmine, galantamine or memantine as if all dementias share Alzheimer neurochemistry, contrary to NICE guidance.
- 04
Using antipsychotic or sedative treatment before analysing triggers, environment, pain, communication and lawful least-restrictive safeguards.
- 05
Ordering predictive genetic tests for an unaffected relative without specialist counselling, informed consent and an affected-person testing strategy.
- 06
Failing to ask about motor neurone signs, swallowing and respiratory symptoms despite the clinically important FTD-MND overlap.