Dementia

Cards · 103

Dementia (Major Neurocognitive Disorder)

An acquired syndrome marked by persistent decline in memory and other cognitive domains severe enough to impair daily functioning.

Mild Cognitive Impairment (MCI)

Measurable cognitive decline beyond normal aging that does not significantly interfere with independent daily activities.

Delirium

An acute, fluctuating disturbance in attention and awareness often caused by underlying systemic medical illness, distinct from dementia.

Alzheimer Disease

The most common cause of dementia, characterized by progressive short-term memory loss and insidious cognitive decline.

Amyloid-beta Plaques

Extracellular protein aggregates of misfolded amyloid-beta peptides characteristic of Alzheimer disease neuropathology.

Neurofibrillary Tangles

Intracellular accumulations of hyperphosphorylated tau protein causing microtubule disruption in Alzheimer disease.

Vascular Dementia

Dementia caused by cerebrovascular disease, often presenting with stepwise deterioration and executive function deficits.

Dementia with Lewy Bodies (DLB)

Neurodegenerative dementia marked by visual hallucinations, fluctuating cognition, and spontaneous parkinsonism.

Alpha-synuclein

The structural protein that aggregates abnormally into Lewy bodies in Lewy body dementia and Parkinson disease.

REM Sleep Behavior Disorder

Loss of normal muscle atonia during REM sleep leading to dream enactment; a strong prodromal marker of alpha-synucleinopathies.

Frontotemporal Dementia (FTD)

Early-onset neurodegenerative disorder marked by progressive behavioral/personality changes or language impairments.

Behavioral Variant FTD

Subtype of FTD presenting with early disinhibition, apathy, loss of empathy, hyperorality, and compulsive behaviors.

Primary Progressive Aphasia (PPA)

A focal neurodegenerative syndrome characterized by isolated, progressive language deterioration.

Normal Pressure Hydrocephalus (NPH)

Reversible dementia syndrome characterized by the classic triad of gait apraxia, urinary incontinence, and cognitive decline.

Creutzfeldt-Jakob Disease (CJD)

A rapidly progressive, fatal prion disease characterized by myoclonus, ataxia, and severe subacute cognitive decline.

Parkinson Disease Dementia

Dementia arising in the context of established, advanced Parkinson disease, typically occurring years after motor onset.

Huntington Disease Dementia

Subcortical dementia associated with chorea and psychiatric changes, caused by a CAG trinucleotide repeat expansion in the HTT gene.

Pseudodementia (Depressive Cognitive Impairment)

Cognitive deficits mimicking dementia secondary to severe major depressive disorder, typically reversible with antidepressant treatment.

Amnesia

Impairment in the ability to learn new information (anterograde) or recall previously learned information (retrograde).

Aphasia

Acquired impairment in language comprehension, production, or expression due to localized cortical brain injury.

Apraxia

Inability to carry out learned, purposeful motor acts despite intact motor strength, sensation, and comprehension.

Agnosia

Inability to recognize and identify objects, persons, or sounds despite preserved sensory functioning.

Executive Dysfunction

Impairment in high-level cognitive processes such as planning, working memory, abstract reasoning, and cognitive flexibility.

Sundowning

Clinical phenomenon where confusion, agitation, and restlessness worsen late in the afternoon or evening.

Confabulation

Production of fabricated or distorted memories about oneself or events without the conscious intention to deceive.

Anosognosia

Lack of awareness or deficit in self-perception regarding one's own neurological or cognitive deficits.

MMSE (Mini-Mental State Examination)

A brief 30-point standardized screening tool used to assess cognitive impairment across multiple domains.

MoCA (Montreal Cognitive Assessment)

A 30-point screening tool with higher sensitivity than the MMSE for detecting mild cognitive impairment and executive dysfunction.

Clock Drawing Test

A rapid screening test assessing visuospatial ability, executive functioning, and abstract numerical reasoning.

Basic Activities of Daily Living (BADLs)

Fundamental self-care tasks including bathing, dressing, eating, toileting, and transferring.

Instrumental Activities of Daily Living (IADLs)

Complex daily activities necessary for independent living, including managing medications, finances, cooking, and driving.

Apolipoprotein E epsilon 4 (APOE-e4)

The major known genetic susceptibility allele that increases the risk of sporadic late-onset Alzheimer disease.

Presenilin Mutations (PSEN1, PSEN2)

Autosomal dominant mutations that cause early-onset familial Alzheimer disease by altering amyloid-beta processing.

Donepezil

A reversible acetylcholinesterase inhibitor used to improve cognitive symptoms in mild-to-severe Alzheimer disease.

Rivastigmine

A dual acetylcholinesterase and butyrylcholinesterase inhibitor available in oral and transdermal patch forms.

Galantamine

A cholinesterase inhibitor that also acts as an allosteric modulator of nicotinic acetylcholine receptors.

Memantine

An uncompetitive NMDA receptor antagonist used to treat moderate-to-severe Alzheimer disease by blocking excitotoxicity.

Lecanemab

A monoclonal antibody directed against amyloid-beta protofibrils, approved to slow progression in early Alzheimer disease.

Neuroleptic Sensitivity

Severe adverse motor and autonomic reactions experienced by dementia with Lewy bodies patients exposed to dopamine antagonists.

Wernicke-Korsakoff Syndrome

Thiamine-deficiency disorder presenting acutely with encephalopathy, ataxia, and ophthalmoplegia, leading to severe chronic amnesia.

Vitamin B12 Deficiency Dementia

A reversible metabolic dementia presenting with memory deficits, macrocytic anemia, paresthesias, and posterior column dysfunction.

Thyroid Dysfunction Dementia

Cognitive slowing and depression-like features secondary to severe hypothyroidism, typically reversible with hormone replacement.

Behavioral and Psychological Symptoms of Dementia (BPSD)

Non-cognitive symptoms of dementia including agitation, apathy, depression, delusions, wandering, and aggression.

Visual Hallucinations in Dementia

Recurrent, well-formed, and detailed perceptions of objects or figures, particularly characteristic of dementia with Lewy bodies.

Hippocampal Atrophy

Volume loss in the medial temporal lobes seen on MRI, serving as an early structural hallmark of Alzheimer disease.

Amyloid-PET Imaging

A molecular imaging modality using radiotracers to detect and visualize brain fibrillar amyloid plaques in vivo.

Tau-PET Imaging

Positron emission tomography using tracers that bind paired helical filament tau to stage neurofibrillary tangle burden.

Fluorodeoxyglucose (FDG) PET

Functional neuroimaging technique detecting regional cerebral hypometabolism patterns specific to different dementia etiologies.

Cognitive Reserve

The brain's resilience to neuropathology, influenced by education, occupation, and intellectual stimulation throughout life.

Mixed Dementia

A condition characterized by the coexistence of two or more dementia pathologies, most frequently Alzheimer disease and vascular pathology.

Chronic Traumatic Encephalopathy (CTE)

A progressive neurodegenerative tauopathy triggered by repetitive head impacts, causing mood changes, aggression, and executive dysfunction.

Cerebral Amyloid Angiopathy (CAA)

Deposition of amyloid-beta within cortical and leptomeningeal blood vessel walls, predisposing to lobar microbleeds and vascular cognitive impairment.

Subcortical Ischemic Vascular Dementia (Binswanger Disease)

A subtype of vascular dementia resulting from severe diffuse arteriolosclerosis of deep white matter, characterized by gait apraxia and psychomotor slowing.

Multi-Infarct Dementia

Vascular dementia caused by repeated, discrete cortical strokes, typically resulting in a stepwise, fluctuating loss of cognitive functions.

CADASIL

An autosomal dominant arteriopathy linked to NOTCH3 mutations that presents with recurrent subcortical ischemic strokes, migraine with aura, and early-onset dementia.

Post-Stroke Dementia (PSD)

Any dementia manifesting within three to six months following a clinical stroke, involving acute neuronal loss and pre-existing vascular pathology.

Strategic Infarct Dementia

Cognitive impairment arising from a single, focal ischemic stroke located in critical brain regions such as the thalamus, angular gyrus, or basal ganglia.

Progressive Supranuclear Palsy (PSP)

A four-repeat (4R) tauopathy presenting with vertical supranuclear gaze palsy, early postural instability with backward falls, and frontal cognitive changes.

Corticobasal Degeneration (CBD)

An asymmetric 4R tauopathy clinically featuring asymmetric parkinsonism, limb apraxia, cortical sensory loss, and alien limb phenomenon.

Multiple System Atrophy (MSA)

An oligodendroglial alpha-synucleinopathy presenting with severe autonomic failure, cerebellar ataxia, parkinsonism, and secondary executive dysfunction.

Semantic Variant PPA (svPPA)

A frontotemporal dementia subtype characterized by anterior temporal lobe atrophy, loss of word meaning, and impaired object recognition.

Nonfluent/Agrammatic Variant PPA (nfvPPA)

A primary progressive aphasia syndrome with left inferior frontal atrophy presenting with effortful, agrammatic speech and speech apraxia.

Logopenic Variant PPA (lvPPA)

A primary progressive aphasia characterized by impaired word retrieval and sentence repetition, most frequently associated with underlying Alzheimer pathology.

Posterior Cortical Atrophy (PCA)

An atypical visual variant of Alzheimer disease presenting with progressive visuospatial deficits, Balint syndrome components, and preserved memory early on.

C9orf72 Hexanucleotide Repeat Expansion

The most frequent genetic cause of familial frontotemporal dementia and amyotrophic lateral sclerosis (FTD-ALS spectrum).

GRN (Progranulin) Mutations

Autosomal dominant mutations causing frontotemporal lobar degeneration with TDP-43 inclusions, marked by asymmetric cortical atrophy.

MAPT (Microtubule-Associated Protein Tau) Mutations

Genetic alterations causing hereditary frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17).

Amyloid Precursor Protein (APP) Mutations

Pathogenic mutations on chromosome 21 causing increased production or aggregation of amyloid-beta, leading to early-onset familial Alzheimer disease.

Down Syndrome-Associated Alzheimer Disease

Early-onset neurodegeneration occurring universally by mid-adulthood due to triplication of the APP gene on chromosome 21.

Limbic-predominant Age-related TDP-43 Encephalopathy (LATE)

A late-life amnestic syndrome mimicking Alzheimer disease, characterized pathologically by non-tau, non-amyloid TDP-43 proteinopathy in the hippocampus.

Argyrophilic Grain Disease (AGD)

A late-onset 4R tauopathy characterized by spindle-shaped grains in limbic structures, often presenting with late-life behavioral instability and mild dementia.

Primary Age-Related Tauopathy (PART)

Neurofibrillary tangle pathology restricted to the medial temporal lobes without significant amyloid-beta plaques, common in very elderly individuals.

HIV-Associated Neurocognitive Disorder (HAND)

A spectrum of cognitive, motor, and behavioral deficits directly caused by chronic neuroinflammation and viral persistence of HIV in the central nervous system.

Neurosyphilis (General Paresis)

A chronic spirochetal brain infection resulting in progressive cortical atrophy, pupillary abnormalities (Argyll Robertson pupils), and severe neuropsychiatric decline.

Subacute Sclerosing Panencephalitis (SSPE)

A delayed, fatal neurodegenerative disease occurring years after a primary measles infection, marked by behavioral deterioration, myoclonus, and dementia.

Progressive Multifocal Leukoencephalopathy (PML)

An opportunistic demyelinating disease caused by JC virus reactivation in immunosuppressed hosts, leading to rapidly progressive multifocal neurological and cognitive deficits.

Herpes Simplex Encephalitis Sequelae

Permanent limbic dementia and severe retrograde/anterograde amnesia resulting from acute HSV-1 necrosis of temporal and inferior frontal lobes.

Anti-NMDAR Encephalitis

An autoimmune disorder mediated by antibodies against NMDA receptors, causing prominent psychiatric symptoms, memory loss, seizures, and dysautonomia.

Limbic Encephalitis

An inflammatory autoimmune or paraneoplastic condition targeting the medial temporal lobes, causing acute to subacute short-term memory loss, confusion, and seizures.

Hashimoto Encephalopathy (SREAT)

A steroid-responsive encephalopathy associated with elevated anti-thyroid antibodies, presenting with relapsing-remitting cognitive decline, tremor, and myoclonus.

Neurosarcoidosis

Non-caseating granulomatous inflammation affecting the meninges, hypothalamus, and cranial nerves, occasionally causing subacute, treatable cognitive decline.

Primary Angiitis of the Central Nervous System (PACNS)

A rare idiopathic vasculitis restricted to cerebral vessels, presenting with recurrent headaches, encephalopathy, multifocal strokes, and progressive dementia.

Lupus Cerebritis (Neuropsychiatric SLE)

Central nervous system manifestation of systemic lupus erythematosus presenting with cognitive dysfunction, mood disorders, or acute confusional states.

Niacin Deficiency (Pellagra Encephalopathy)

A nutritional deficiency characterized by the classic triad of diarrhea, dermatitis, and dementia, responsive to vitamin B3 repletion.

Copper Toxicity (Wilson Disease Dementia)

Autosomal recessive ATP7B mutation causing toxic copper accumulation in the basal ganglia and liver, producing parkinsonism, dysarthria, and subcortical dementia.

Hepatic Encephalopathy

Reversible, fluctuating neurocognitive impairment due to hyperammonemia and portosystemic shunting in advanced liver cirrhosis.

Uremic Encephalopathy

Metabolic cognitive decline and fluctuating awareness caused by the accumulation of toxic nitrogenous metabolites in end-stage renal disease.

Chronic Carbon Monoxide Neurotoxicity

Delayed neurological sequelae following CO exposure, characterized by demyelinating leukoencephalopathy, globus pallidus necrosis, and severe cognitive impairment.

Heavy Metal Neurotoxicity (Lead/Mercury)

Toxic encephalopathy resulting from chronic exposure to industrial metals, causing tremor, mood lability, and progressive cognitive decline.

Methotrexate-Induced Leukoencephalopathy

Chemotherapy-induced white matter necrosis leading to progressive apathy, memory loss, and motor deficits following intrathecal or high-dose systemic administration.

Radiation-Induced Leukoencephalopathy

Delayed white matter damage and radionecrosis months to years following cranial radiotherapy, manifesting as progressive subcortical dementia.

Chronic Subdural Hematoma

Gradual venous bleeding beneath the dura mater after minor head trauma in elderly patients, presenting as a treatable mimic of progressive dementia.

Brain Tumor-Related Cognitive Impairment

Cognitive decline caused by direct parenchymal infiltration, mass effect, or vasogenic edema from primary or metastatic intracranial neoplasms.

Dialysis Dementia (Dialysis Disequilibrium Syndrome)

A progressive encephalopathy historically tied to aluminum intoxication in dialysate fluids, featuring dysarthria, myoclonus, and profound dementia.

Obstructive Sleep Apnea-Related Cognitive Decline

Reversible executive and attentional impairment driven by chronic nocturnal intermittent hypoxia and micro-arousal-induced sleep fragmentation.

Adrenoleukodystrophy (Adult Cerebral Form)

An X-linked peroxisomal disorder caused by ABCD1 mutations that leads to very long-chain fatty acid accumulation, rapid inflammatory demyelination, and dementia.

Metachromatic Leukodystrophy (Adult Form)

An autosomal recessive lysosomal storage disorder caused by arylsulfatase A deficiency, manifesting in adulthood with psychiatric changes, spasticity, and dementia.

Niemann-Pick Disease Type C

An autosomal recessive lipidosis causing vertical supranuclear gaze palsy, ataxia, gelastic cataplexy, and progressive intellectual deterioration.

Gerstmann-Sträussler-Scheinker Disease (GSS)

A rare inherited prion disease caused by PRNP gene mutations, characterized by adult-onset progressive cerebellar ataxia, spasticity, and late dementia.

Fatal Familial Insomnia (FFI)

A genetic prion disease associated with a PRNP D178N mutation, causing refractory insomnia, dysautonomia, endocrine dysfunction, and progressive dementia.

Hypoxic-Ischemic Encephalopathy

Diffuse cerebral damage following cardiac arrest or severe systemic anoxia, resulting in persistent global cognitive deficits or amnestic syndromes.

Post-Intensive Care Syndrome (PICS-Cognitive)

Persistent cognitive deficits across memory, attention, and executive domains acquired following critical illness and prolonged sepsis or mechanical ventilation.

Anticholinergic Burden-Induced Cognitive Decline

Iatrogenic, potentially reversible cognitive impairment caused by cumulative blockade of muscarinic acetylcholine receptors by multiple chronic medications.