Movement disorders and Parkinson's Flashcards
Ballismus
- Description
- Pathophysiology
- Cause
High amplitude, flailing limbs.
Hemiballismus- on one side of the body
Pathophysiology
- Disruption in the subthalamic nucleus
- Internal globus pallidus is not excited so direct pathway is promoted
Cause
- Stroke
Tics
- Description
- Exacerbating and relieving factors
Short, repetitive movements with premonitory urge.
Simple movements
- Blinks, coughing
Complex
- Jumping, twirling
Plus (with simple/ complex)
- Motor disorder
Coprolalia [rare]
- Swearing
Exacerbated by:
- Anxiety
- Fatigue
Reduced by:
- Distracting
- Concentration
Tourette’s syndrome
Severe expression of a spectrum of tic disorders
Composed of multiple motor tics and at least one phonic tic
Causes of tics
Co-morbidity
- ADHD [50%]
- OCD [1/3]
- Anxiety [up to 50%]
Genetic inheritance
- Involves many genes
Post-infectious immune response
Chorea
- Description
Jerky, brief, IRREGULAR contractions
- Not repetitive
- Not rhythmic
Flows from one muscle to the next
- Fidgety, restless
Chorea
- Pathophysiology
- Causes
Disruption in the subthalamic nucleus
- Promotes the direct pathway and inhibits indirect pathway
Cause
- Huntington’s disease [degenerative]
- Neuroleptics [antipsychotics]
Huntington’s chorea
- Genetics
Autosomal dominance with complete penetrance [ clinical symptoms are present in all individuals affected by the disease]
Trinucleotide repeat
- Chromosome 4
- Longer repeat sequence = the earlier the disease presents
Repeat sequence tends to enlarge with each generation
Huntington’s chorea
- Clinical presentation [cognitive, behavioural, physical]
Cognitive
- Inability to make decisions
- Inability to mutli-task
- Slow in thought
Behavioural
- Irritable
- Depressed
- Apathic
- Anxiety
- Delusions
Physical
- Chorea
- Motor persistence [i.e protruding tongue and withdrawing unwilling]
- Dystonia
- Eye movements
Myoclonus
- Description
- Causes
Twitching of a muscle or a group of muscles
- Rapid onset and offset
Postive = muscular contractions Negative = muscular inhibitions
Causes:
- JME
- Brain hypoxia
- Prion disease [CJD]
Myoclonus
- Pathophysiology
Not fully understood
Suggested
1. Imbalance between excitatory and inhibitory neurotransmitters
- Deviation of the motor control system, causing a brief equilibrium
Dystonia
- Description
- Causes
Abnormal twisting posture - Axial - Facial - Truncal Jerky tremor
Causes:
- Stroke
- Brain injury
- Encephalitis
- PD
- HD
Dystonia
- Pathophysiology
Not well understood
- Abnormal activity in:
- Motor cortex + supplementary areas
- Cerebellum
- Basal ganglia - Abnormal dopaminergic activity in basal ganglia
Tremor
- Action
- Body parts affect
- Classifications
- Involuntary
- Rhythmic
- Alternating movements of part of the body
Parts affected:
- Limbs
- Head
- Chin
- Soft palate
Can occur at rest, at a particular body position [postural] or when performing an action [kinetic]
Most common
- Essential tremor
Tremor
- Pathophysiology
Caused by increased activity in cerebellothalamocortical circuit.
In PD
- Dopamine dysfuntion in the pallidum
In essential tremors
- GABAergic dysfunction in cerebellum
MRI focussed ultrasound therapy
Treatment method for resistant essential tremors
- Used for PD
Drug treatments for tics, chorea and ballismus
D2 receptor blocking agents
Dopamine depleting agents
Atypical antipsychotics
Problems caused by D2 blocking agents
Affects the basal ganglia
Acute:
- Oculogyric crisis
- Neuroleptic malignant syndrome
Subacute
- Drug induced Parkinsonism
Long term
- Tardive dyskinesias
Oculogyric crisis
Prolonged, involuntary upward deviation of the eyes
- Neck + trunk extension
- Jaw spasm with or without tongue protrusion
Acute side effect of neuroleptics and other D2 blockers
Neuroleptic malignant syndrome
Acute reaction to D2 blocking drugs
Features:
- Rigid muscles due to Raised creatine phosphokinase
- Fever
- Autonomic instability
- Confusion
Tardive dyskinesia
Long term side effect of D2 blocking agents.
- Choeric oral/facial movements
- Dystonic trunk
Mechanism
- Dopamine sensitivity of basal ganglia ?
Treatment:
- Gradually withdrawal drug
- Substitution with atypcial anti-psychotic
- Dopamine depleting agent [tetrabenazine]
Parkisonism
Hypokinetic movement disorders
Symptoms:
- Slow
- Stiff
- Shaky
Signs:
- Bradykinesia
- Akinesia
- Rest tremor
- Rigidity
Non motor Parkinsonism symptoms
Mood:
- Depression, anxiety
Dementia
Autonomic:
- Postural hypotension
- Hypersalivation
Sleep disturbance
- Restless legs
- REM parasomnia
Reduced sense of smell
Parkinson’s disease pathophysiology
Destruction of cells in substantial nigra
- Decreased DA input into the striatum
- Reduced activation of direct pathway
- Reduced inhibition of indirect pathway
Histopathological hallmark of PD
Lewy bodies
- Abnormal accumulation of proteins inside nerve cells
