PD & Drug Therapy Of Basal Ganglia Disorders Flashcards
Ballismus
- Description
- Pathophysiology
- Causes
A high amplitude flailing of the limbs
Hemiballismus- one side of the body
Pathophysiology
Disruption of the STN
Indirect pathway is not excited so direct pathway is promoted
Cause
Stroke
Chorea -Description -Pathophysiology -Causes .
Jerky, brief, irregular contractions
non-repetitive, non-rhythmic, flow from one muscle to the next
Fidgety, restless
Pathophysiology
-Disruption in STN, indirect pathway is inhibited, direct pathway is promoted
Causes
- Huntingdon’s Disease (degenerative)
- Neuroleptics (antipsychotics)
Tics
- Description
- Exacerbating and relieving factors
Short, repetitive movements with a premonitory urge. Simple movements - blinking, coughing Complex movements - jumping or twirling Plus: motor disorder
Coprolalia (rare): swearing -
Worsened with
- fatigue
- anxiety
Reduced by
- Distractions
- Concentration
Causes of Tic Disorder
Co-morbid conditions
ADHD 50%
OCD 33.3%
Anxiety 50%
Complex genetic inheritance
Post infectious immune
Tourette syndrome
more severe expression of a spectrum of tic disorders
multiple motor tics and at least one phonic tic
Huntington’s chorea
-genetics
Autosomal dominant with complete penetrance
Trinucleotide repeat on chromosome 4
-longer the repeat sequence the earlier the disease presents
Repeat sequence tends to enlarge with each generation
Huntington’s chorea
-clinical presentation
Cognitive
-Inability to make decisions, multitask, slow in thought.
Behavioural
Irritability, depression, apathy, anxiety, delusions.
Physical
Chorea, motor persistence, dystonia, eye movements.
Myoclonus
- Description
- Causes
Quick, brief, involuntary muscle jerk.
Rapid onset and offset
Positive=muscular contractions
Negative=muscular inhibitions
Causes
- Juvenile Myoclonic Epilepsy
- Brain hypoxia
- Prion disease
Describe the pathophysiology of myoclonus
Unknown
1) Possibly an imbalance between excitatory and inhibitory neurotransmitters
(can be treated with antiepileptic drugs)
2) Perturbations of the motor control system leading to a brief disequilibrium
Explain why present at multiple levels e.g cortical, subcortical , spinal etc.
Dystonia
- Description
- Causes
Abnormal twisting posture
(often axial, facial, truncal, associated with jerky tremor)
Causes
Stroke Brain injury Encephalitis Parkinsons disease Huntington’s disease
Dystonia
-pathophysiology
- abnormal activity in the motor cortex, supplementary motor areas, cerebellum, basal ganglia
- Abnormal dopaminergic activity in basal ganglia (dystonia causes by blocking DA receptors, some dystonias are Levodopa responsive)
What is a tremor?
Involuntary, rhythmic, sinusoidal alternating movements of part of the body.
in limbs, head, chin, soft palate
When can a tremor occur?
At rest
Postural (in a particular body position)
Kinetic (when performing an action)
Most common: Essential tremor (simple kinetic tremor)
Describe the pathophysiology of a tremor
Increased activity in the cerebellothalamocortical circuit.
In PD: Dopamine dysfunction in the pallidum results in this.
In Essential Tremors:
GABAergic dysfunction in the cerebllum causes this.
MRI focussed ultrasound therapy
Treatment method for treatment resistant Essential Tremor
-used for PD
