Parkinsons Flashcards
some symptoms of Basal Ganglia Disorders
- Abnormal motor control
- Altered posture
- Affects muscle tone
- Dyskinesia
pattern of disorders with basal ganglia
right basal ganglia probelm
contralateral symptoms
define Basal ganglia disease
is a group of physical dysfunctions that occur when the group of nuclei in the brain known as the
basal ganglia fail to properly suppress unwanted movements or to properly prime upper motor neuron circuits to initiate motor function
what happens to the direct and indirects pathways on the cortex in parkinsons?
overall inhibitory effect!
normal effect of dopamine in the direct and indirect pathway?
D1 receptors>> stimulates direct>> increase cortex stimulation
D2 recepters>> inhbits indirect> increase cortex stimulation
what is parkinsons disease?
Chronic, progressive movement disorder characterised by a triad of bradykinesia, tremor and rigidity
Degeneration of substantia nigra causes deficiency of dopamine
which part of SN in parkinsons is defected?
SN>> pars compacta
degeneration
(ily yam 3yoona)
pathophysiology of parkinsons
Causes of parkinsons?
What is seen under the microscope?
clinical features of Parkinson’s
what type of tremor do ppl w/ parkinsons present?
A ‘pill-rolling’ movement of the index and middle fingers against the thumb pad is characteristic.
how is the rigidity described? why do they get it?
lead pipe rigidity>> resistance through the full range of movement.
if tremor is also seen w/ the rigidity >> cogwheel sensation (tremor superimposed on rigidity).
why do patients display ‘resting tremor’, with supposedly inactive muscles?
It just so happens that when the forearms are resting on the lap or on the arms of a chair, the forearm/hand muscles are not fully at rest. If the limb is fully supported at the elbow and wrist, the tremor disappears. The tremor also disappears during sleep.
describe how the handwriting of PD patients
Micrographia
Difficulty in writing is a common early feature of PD, written letters become small and irregular. Loss of writing skill is attributable to concontraction of wrist flexors and extensors, owing to a marked reduction of supraspinal activation of 1a interneurons synapsing on antagonist motor neurons.
why do they get Bradykinesia?
Bradykinesia means slowness of movement. Patients report that routine activities, such as opening a door, require deliberate planning and consciously guided execution. theres a reduction of the ‘initial agonist burst’ of electrical charge accompanying the first contraction of relevant prime movers.
Normally, the basal ganglia contribution to movement is initiated some milliseconds after the premotor cortex and cerebellum have raised the firing rate of motor-cortex neurons to threshold at a spinal lower motor neuron level.
In PD the boost to lower motor neuron activation is weak because of the weakened contribution from the supplementary motor area SMA.
which symptoms does not progress at the same rate as bradykinesia, rigidity, or gait problems?
describe why it occurs?
Tremor
(The aetiology of tremor in PD may reflect the combination of dysfunction of the basal ganglia and the cerebello–thalamo–cortical pathway, which then results in the appearance of a tremor
in tremor, what is the commonest sequence of limb involvement?
1 upper limb to the ipsilateral lower limb within 1 year,>>> followed by contralateral limb involvement within 3 years
what is Parkinsonism plus syndrome
Parkinsonism plus syndrome is a group of heterogeneous degenerative neurological disorders, which differ from the classical idiopathic Parkinson’s disease in certain associated clinical features, poor response to levodopa, distinctive pathological characteristics and poor prognosis
what is Multiple system atrophy
is a Parkinson plus degenerative disorder of the brainstem, basal ganglia, and central autonomic neurons.
Patients present with one or more of the following:
- Akinesia/rigidity with little or no tremor.
- One or more signs of autonomic failure: postural hypotension, bladder/bowel dysfunction, impotence, dry eyes and mouth, pupillary abnormalities, impaired sweating.
- Bilateral pyramidal tract degeneration leading to pseudobulbar palsy and ‘upper motor neuron signs’ in the limbs.
- Poor ocular convergence.
- L-dopa is of little value.
when examining patient, explain his gait and features that come along with it?
- Bradykinesia
- Patient will be slow to initiate movement
- May see a ‘festinating gait’
- Hypertonia (rigidity)
- Will take more steps to turn around
- Reduced arm swing
- Slightly ‘stooped’ (flexed) posture
what posture will they present with?
•Slightly ‘stooped’ (flexed) posture
term for Reduced facial expressions?
•Hypomimia
masked face (reduced facial expression)
when examining tone, how can the situation be accentuated?
•by asking the patient to perform a distracting activity
e.g. counting backwards, moving arm up and down
