Atypical Parkinsonism Flashcards
What are the motor control features related to atypical Parkinsonism CBS / PSP
Core diagnostic features of
PSP ( progressive supranuclear palsy)
CBS (corticobasal syndrome)
- vertical eye movements
- dyspraxia
- bradykinesia
- gait
What are the core PSP clinical features
Ocular motor dysfunction
1. Vertical supranuclear gaze palsy
2. Slow velocity and vertical saccades
3. frequent macro square wave jerks or “eyelid opening apraxia”
Postural instability
1. Repeated unprovoked falls within 3 yrs
2. Tendency to fall on the pull tests within
3 yrs
3. More than two steps backwards on the pull test within 3 years
Akinesia
1. Progressive gait freezing within 3 years
2. Parkinsonism, akinetic-rigid, predominantly axial and levodopa resistant
3. Parkinsonism, with tremor and or asymmetric and or levodopa resistant
Cognitive dysfunction
1. Speech/ language disorder
2. Frontal cognitive/ behavioural presentation
3. Corticobasal syndrome
What are the diagnostic degrees of a PSP diagnosis
Definitive PSP
Predominance type - any presentation
Neuropathological diagnosis
Probable PSP
(Specific but not sensitive)
(O1 or O2) + (p1 or p2) = PSP (Richardson)
(O1 or O2) + A1 = PSP (progressive gait freezing)
(O1 or O2) + (A2 or A3) = PSP (predominantly Parkinsonism)
What is CBS and its diagnostic standards
CBS is corticobasal syndrome
Probable CBS
Asymmetric presentation of 2:
-limb rigidity or akinesia
- limb dystonia
- limb myoclonus
Plus 2:
- orobuccal or limb apraxia
- cortical sensory deficit
- alien limb phenomenon
Possible CBS
May be symmetric
1 of:
-limb rigidity or akinesia
- limb dystonia
- limb myoclonus
Plus 1:
- orobuccal or limb apraxia
- cortical sensory deficit
- alien limb phenomenon
What is CBD and its criteria
CBD is corticobasal degeneration.
Probable sporadic
- insidious onset and gradual progression
- 1 year duration
>_ 50 age onset
Possible
- insidious onset and gradual progression
- 1 year duration
- no minimum age at onset
Exclusion criteria:
- LBD
- MSA
- ALS
- Aphasia
- Structural
- Genetic
- AD
How are eye movements affected by cortical control in CBD
Cortical : frontal eye lids
Apraxia
Dorsolateral prefrontal cortex (DLPFC)
- remembered saccades
Posterior eye fields (PEF)
- reflexive saccades to target
Frontal eye fields (FEF)
- output to superior colliculus
Can be effected in any cortical processes
Stroke, AD, DLB, CBD, FTD
Classically: AT and EOA
delay in initiation - to command ocular apraxia
Head thrusts may be used to generate eye movements
Supranuclear gaze palsy
Tau deposition in the brain
What is the saccadic system in PSP
Mid brain “supra-nuclei”
2 nuclei that control vertical eye movement
1. Interstitial nucleus of Cajal (gaze holding)
2. riMFL (saccadic velocity)
Slow velocity, impaired gaze holding, limitation of range
Vertical > horizontal
What are the other eye signs in PSP
Decreased blink rate
Levator inhibition
Blepharosprasm (involuntary scrunching of eyes)
What are the core features of apraxia
- Limb kinetic
(Loss of independent movement)
(Test, mime playing piano)
(Primary motor cortex)
(Disease ALS) - Ideomotor
(Loss of skilled/ learned movement)
(Features, mimes command/* initiation)
(Parietal association and white matter)
(Disease CBD) - Ideational
(Loss of sequence)
(Show me how to post a letter)
(Left hemisphere - parieto - occipital/ temporal)
(Disease stroke)
What are the different types of apraxia?
Eye movement apraxia
Eye opening apraxia
Orobuccal apraxia
Dressing apraxia
Gait apraxia
Truncal/ bottom apraxia
Apraxia of speech
What is ideomotor apraxia and its features
Ideomotor apraxia is the loss of skilled/ learned movement
- typically left hemisphere dominant
- imaging shows asymmetric tauopathies and atrophy.
Features of this may include:
- limb/ hand position
- amplitude
- pattern/ sequencing of movement
- using contralateral hand to help
- body part substitution
- hard vs easy
- command > miming
- low frequency > high frequency
- abstract > gestures
(Easiest limb moving is thumbs up)
Bradykinesia / micrographia
Slowness of movement and small cramped handwriting
- Parkinson’s type
(Decreased amplitude and velocity with decrement) - PSP type
(Fast and small/ reduced amplitude no decrement) - PSP-PGF
(Pallidal) profound bradykinesia and micrographia
What are the differences in gait between PD and PSP
PD
- stooped posture
- decreased arm swing
- small steps
PSP
RS
- erect posture
- neck extension
- poor balance
- large eccentric steps
- collapse back into chair
- falls
PGF
- freezing
- turning
- doorway difficulty
- improved by cueing
What is the pathogenesis of gait disorders in PSP
Imaging suggests severity of disorder correlates with hypometabolism in PFC and STN
falls are associated with thalamic atrophy
Freezing associated with PPN (peduncle pontine nucleus)
