Frontotemporal Dementias Flashcards
What are the FTD variants?
Behavioral, language, motor
What was the behavioral variant of FTD (bvFTD) previously called?
Pick disease
How do Pick bodies differ from pathology in AD?
- Pick bodies have straight, fibrous appearance of tangled tau protiens.
- Neurofibrillary tangles in AD have a paired and coiled construction
Neuropathology of bvFTD
- Tau proteins are mutated and bind to microtubles, produce toxic inclusions
- Argyrophilic circular inclusions are known as Pick bodies, co-occur with balloon-shaped Pick cells in neuronal cytoplams
Where are common cerebral locations of Pick bodies?
- Amygdala
- Dentate gyrus
- Hippocampus pyramidal cells- CA1 section and subiculum
- Hypothalamic lateral tuberal nucleus
- Dorsomedial region of the putamen
- Globus pallidus
- Locus ceruleus
- Mossy fibers, monodendritic brush cells in granule cell layer of the cerebellum
- Frontal and temporal neocortex
What is the most common FTD variant?
bvFTD
bvFTD age of onset and gender trends
- More common in men than women
- Onset between 40-65, average age 54
Early symptom presentation in bvFTD
- behavioral disinhibition: begins with changes in personality, interpersonal conduct, emotional regulation
- apathy or inertia
- loss of sympathy or empathy
- perseverative, stereotyped, or compulsive/ritualistic behavior
- Hyperorality, dietary changes
- Executive/generation deficits, sparing of relative memory and visuospatial functions
What are 3 subtypes of primary progressive aphasia (PPA)
- nonfluent/agrammatic (progressive nonfluent aphasia)
- semantic dementia (temporal variant FTD)
- logopenic variant (logopenic progressive aphasia and phonological variant PPA)
What neuropathology underlies most cases of PPA?
tau-positive, ubiquitin/TDP43-positive frontotemporal lobar degeneration or AD pathology
What neuroanatomic damage is most associated with nonfluent PPA?
-Left posterior frontal and insular regions
What neuroanatomic damage is most associated with semantic PPA?
-Anterior temporal region
What neuroanatomic damage is most associated with logopenic PPA?
-left temporoparietal regions
Average length from PPA onset to death
12 years
Core features of logopenic variant PPA?
- Impaired single-word retrieval in spontaneous speech and naming
- Impaired repetition of sentences and phrases
Core features of semantic variant PPA?
- Impaired confrontation naming
- Impaired single-word comprehension
Core features of nonfluent variant PPA?
- Agrammatism in language production
- Effortful, halting speech with inconsistent speech sound errors
What characterizes the motor variant of FTD?
-progressive deterioration of motor functions with cognitive and psychological sx
What are 3 subtypes of motor FTD, and which is most common?
- Progressive supranuclear palsy (most common)
- Corticobasal degeneration
- FTD with motor neuron disease
Neuropathology of PSP?
-Astrocytic lesions, tau-postive neurofibrillary tangles, neuropil threads within the brainstem and basal ganglia
Neuropathology of CBD?
-Asymmetrical atrophy of bilateral premotor cortex, superior parietal lobules, and striatum
Neuropathology of FTD-MND?
-ubiquitin-based pathology rather than tau pathology, involving frontal and temporal lobes
Average time from onset of PSP to death?
5 years, with clinically significant motor problems typically merging about 4 years after disease onset
FTD-MND age of onset and time to death?
- 55 years, equal male to female ratio
- Rapid progression from diagnosis to death, typically occurring in late 50’s
CBD age of onset?
Ranges from 50’s to 70’s
Features of FTD-MND?
Core:
- Dementia, impaired memory and EF
- Speech production deficits
- Significant disinhibition
- Personality change
Additional:
- Muscle atrophy, weakness, cramps, clumsiness
- slowed vertical saccades
- weak respiratory muscles
- hyperflexia
- fasciculations
- dysphagia and dysarthia
Core features of CBD?
- Limb apraxia
- Alien limb syndrome
- Cortical reflex myoclonus
- Cortical sensory impairment
- Exec. dysfunction is also common
Core features PSP?
- Supranuclear vertical gaze palsy (impaired downward gaze)
- Bradykinesia
- Rigidity
- Swallowing problems
- Frequent falls
- Usually involves behavioral and cognitive changes, especially exec. dysfunction
What is agrammatism?
-inability to speak grammatically, typically because of simplified sentence structure and errors in tense, number, and gender, omission of function words (telegraphic speech)
What does argyrophilic mean?
- Affinity for silver; binding to silver salts
- in Picks bodies
What is surface dyslexia?
- Common feature of semantic FTD
- Inability to recognize words as a whole, resulting in failure to read irregularly spelled words that cannot be sounded out phonetically
- Dyseideic dyslexia
What are vertical saccades?
- Very short, rapid vertical movement of both eyes at the same time
- Saccades are the fastest movements produced by the human body; once underway, they cannot be altered by will
- Slowed in FTD-MND
