2ND LECTURE

Movement disorder[involuntary ] and ataxia; extra pyramidal and cerebellar system.

The plan

- Movement disorder introduction- Hypokinesis movement disorder[ ex. Parkinsonism]- Hyperkinetic movement disorder- Cerebellar disorder and ataxia

Introduction; extra pyramidal system function

- Regulate reflexes ad maintaining posture tone- control is involuntary and subconscious- It s indirect activation pathways

Where is the extrapyramidal system located?

- It is make up of the subcortical nuclei called the BASAL GANGLIA

Basal ganglia

Striatum/subthalmic nucleusglobus palidusthalamus and cortexdesired movement is normal situations; tics or involuntary movement when striatum has to much control

Extra pyramidal system;- picture

Lesions of the basal ganglia cause:

1. Hypokinetic movement disorder[ akinesia]- lack of physical movement when a motor command is given

2. Hyperkinetic movement disorder[ dyskinesia]- excessive involuntary body movement.

Hypokinetic movement disorder[ akinesia]

- Parkinson syndromeo Bradykinesia (slowness of initiation of voluntary movement with progressive reduction

in speed and amplitude of repetitive actions) obligatory signo Muscular rigidity obligatoryo 4-6 Hz rest tremoro Postural instability not caused by primary visual,vestibular,cerebella or proprioceptive

dysfunction.o Freezing- inability to move muscle in desired direction

syndrome- combination of signs and symptoms with common pathogenesis e.g i) subarachnoid hemorrhage- headache, meningeal ii) inflammation- fever, etc

UK’s Prkinson’ disease society brain abn clinical diagnostic criteria

- Cut section of the midbrain where a portion of the substanstia nigra is visible- Diminished sunstantia nigra as seen in Parkinson’s disease[>80% symptom are showed]- Lack of dopamine produce by substantia nigra decrease basal ganglia activation.

Hyperkinetic movement disorder-involuntary movement that are sometimes suppressible for a period of time

- Tremor- Dystonias- Chorea (dancing),Athetosis,Ballism- Myoclonus- Tics 1. TremorExcessive involuntary rhythmic oscillation of a body part caused by contraction of

antagonist muscle groups.o Rest tremor- [Parkinson]o Postural tremor- happen in certain conditiono Intention tremor- happen when doing somethingo Ruberal tremor- 1 extremity

2. Chorearapid, jerky, purposeless movement involving limbs, trunk or face of irregular timing3. Athetosiswrithing of limbs, most prominent distally4. Ballismlarge amplitudes ‘flinging’ of a limb, proximal activation of muscles.5. Dystonissustained agonist’antagonist muscle contractions

o Torsion dystoniao Cervical dystonia, torticolliso facial dystoniao Hand/arm dystonia

6. Myoclonusrapid discrete simple jerks of the body part through involuntary activation7. Ticsinvoluntory simple or complex movement or vocalization

Cerebellar system

- Does not initiate motor movements, but help with their coordination- Function balance and coordination- Brainstem- mendulla oblongat, pons and midbrain.

Ataxia[ witout control] and cerebellar system

loss of coordination of voluntary movement

Cerebellar ataxia

- Postural and/or gait[when stand up] instability- Dysmetria undershoot or overshoot of intended movement to a target- Dysdiadokinesia inability to perform rhythmic movement.

Type of ataxia

- Cerebellar ataxia- postural, dysmetria, dysdiadokinesia (coordination)- Vestibular ataxia- nausea ,vomiting, vertigo, disequilibrium (dizines)- Sensory ataxia- sensation disorder

Different between

Extrapyiramidal Cerebellar problemMoving or at rest Only when you try to do something

Categorization of movement disorder

movement disorder

pyramidal syndromes

spasticity

basal ganglia disorder

hyperkinesia

hypokinesia

miscellaneous motor-sensory

behavior

cerebellar disorder

ataxia