862 - movement disorders

possible risk factors for Parkinson’s

Pesticide exposure, severe head injury, family history, & increasing age

Parkinson’s symptoms occur once __% of dopamine is gone

70-80

direct pathway facilitates…

intended movement

decreased activation of the D1 pathway results in…

less movement → bradykinsesia

indirect pathway inhibits…

unwanted movement

decreased activation of the D2 pathway leads to…

unwanted movement → resting tremors

substantia nigra pars compacta & Parkinson’s

• substantia nigra pars compacta produces dopamine used to activate D1 & D2 pathways

• PD is due to death of dopamine producing cells in substantia nigra

preclinical/premotor sign that is associated with highest risk for developing PD

rapid eye movement sleep disorder

preclinical/premotor signs for Parkinson’s

• sleep dysfunction

• olfaction Loss

• constipation & GI involvement

• mood changes

bradykinesia definition

slowness of movement w/ progressive loss of amplitude or speed during attempted rapid alternating movements

hypokinesia definition

reduced amplitude of movement

akinesia definition

slowness in initiating movement

4 clinical signs that lead to clinical dx of PD

1. bradykinesia

2. rigidity

3. tremor

4. postural instability (asymmetrical onset)

tremor is absent in __% of pt w PD

20

true diagnosis of PD via…

neuropathological imaging on autopsy

red flags that would led you to consider atypical Parkinsonism

• symmetrical onset

• early & frequent falls

• poor response to levodopa

• rapid progression

• absence of tremors

• autonomic dysfunction

features unusual early in clinical course of PD

• prominent postural instability in first 3 years after symptoms onset

• freezing in first 3 years

• hallucinations unrelated to meds in first 3 years

• dementia preceding motor symptoms or in first year

essential tremor - PD differential dx

• symmetrical postural tremor that worsens w/ movement in distal extremities, head, & voice

• improves w/ alcohol, beta blockers, & deep brain stimulation

• family hx common

• progressive

vascular Parkinsonism - PD differential dx

• clinical symptoms similar to PD w/ stepwise progression but little to no response to levodopa

• presence of basal ganglia/thalamic infarction

dementia w/ levy bodies - PD differential dx

onset of motor symptoms w/ accompanied dementia & visual hallucinations, fluctuations in attention & cognition, poor response to levodopa

normal pressure hydrocephalus - PD differential dx

• characterized by cognitive changes, urinary incontinence, & gait disorder

• build up of CSF in ventricles → place pressure on surrounding brain structures

initial motor symptoms of PD

• resting tremor

• bradykinesia

• rigidity

• micrographia

• hypophonia

• decreased facial expression

• difficulty w/ bed mobility

• mild incoordination

• gait abnormalities

one of the first signs seen in early PD

reduced arm swing

gait abnormalities associated with early PD

• reduced arm swing

• decreased stride length

• difficulty turning

narrowing of therapeutic window occurs ___ after PD diagnosis

5-8 years

motor symptoms associated with 5-8 years after PD diagnosis

• retropulsion & postural instability

• stooped posture

• akinesia

• freezing/festination

• cognitive changes affecting motor function

festination

move forward w/ rapid & smaller steps, associated w/ COG moving forward over feet

freezing of gait definition

brief episodic absence or reduction of forward progression of the feet despite the intention to walk

festination & freezing of gait worsen when…

• turning

• transitioning visual surfaces

• crowed areas

• stress

• tight spaces

pts with PD & learning

• little to no deficits in motor skill acquisition but slower rates of learning

• sensory info & cues may help learn motor skills but skills are less flexible & more context specific than typical learning

important source of misdiagnosis or delayed diagnosis for PD

non-motor symptoms as presenting complaint

non-motor symptoms PD

• pain

• fatigue

• lack of smell

• sleep disturbances

• mood disorders

• flat affect

• autonomic disorders (orthostatic hypotension, bowel/bladder incontinence, drooling, ED)

• cognitive deficits

• dysphasia

• impulse control disorders

PD prognosis

• progressive neurodegenerative disease

• survival rates of pt w/ early PD are about the same as general US population

• pt do not often die of PD

predictors for more rapid decline PD

• postural instability & gait disturbance initial presentation (PIGD subtype)

• older age at onset

• prominent bradykinesia & rigidity at diagnosis

• early cognitive dysfunction

• axial symptoms > appendicular symptoms

predictors for slower decline

tremor dominant initial presentation (tremor dominant subtype)

American Academy of Neurology recommendation for initiation of medical treatment for PD

once patient demonstrates functional disability

strategy training theory

bypassing the basal ganglia loop & utilizing the intact cortical, cerebellar, or brainstem pathways to normalize movement

cognitive strategies for PD

• consciously thinking about desired movement

• think about stopping mid freeze & “resetting”

external cues can be useful in improving movement in the moment but..

no evidence for long term (6 month) carry over effect once cue is removed

external cues for PD examples

• metronome or songs w/ specific bpm

• lines perpendicular to ambulation path to facilitate large amplitude steps

• pt don’t freeze on stairs!

hallmarks of progressive supranuclear palsy

• vertical gaze palsy

• symmetrical onset

• frequent, early falls

progressive supranuclear palsy motor symptoms

• early gait & balance problems, incoordination, slowed or absent balance reactions, frequent falls

• slowed movement, rigidity (often axial), dystonia (commonly at neck & hands)

progressive supranuclear palsy & corticobasal degeneration shared pathology

• abnormal accumulation of tau protein inside brain cells

• leads to neuronal damage & death, particularly in BG, brainstem, & cerebral cortex

multiple system atrophy pathology

• abnormal accumulation of alpha-synuclein protein

• protein builds up in glial support cells (in PD, protein builds up as Lewy bodies

hallmarks of multiple systems atrophy

• early autonomic dysfunction

• early falls

• cerebellar signs (MSA-C)

hallmarks of corticobasilar degeneration

• asymmetrical presentation

• early cognitive decline

• apraxia

• alien limb syndrome

Huntington’s disease pathology

• caused by repeat of Huntington disease gene

• degeneration of neurons that act in indirect pathway → chorea

  • followed by loss of neurons in white matter, cerebral cortex, & thalamus

how many gene repeats needed to be diagnostic of huntington’s disease

36

clinical diagnosis of HD suspected if…

• family history of HD

• progressive motor abnormalities w/ chorea & impairment of fine motor skills

• mental changes (cognitive decline, personality changes, depression)

HD prognosis

• mean duration of disease is 17-20 years

• most common COD is pneumonia followed by suicide

chorea definition

involuntary unwanted movements that are non-rhythmic & non-repetitive

chorea & HD

• often starts in distal extremities & facial muscles - progress proximally & to axial skeleton

• present at all times when awake

• increase w/ voluntary movements & stress

• progress to muscles of swallowing & speech later in disease

most frequent non—motor symptoms of HD

depression & anxiety

medical management of HD

• no mediations available to delay progression of HD

• drugs available to treat chorea (only symptom that has been successfully treated)

• parkinsonian drugs have not been successful in treating hypokinesia

Berg cut off for fall risk

<40

go-to intervention for PD

walking!! (HIGT)