Pyramid & Extrapyramidal disorders & Parkinsons

Pyramidal SystemWhere are the pyramids of the brain?

Anterior potion of the medulla oblongata

Pyramidal System. What is its structure?

The pyramidal tract (aka Corticospinal) travels between the cerebral cortext of the brain & the spinal cord (via the pyramid of the medulla).

What is it function? The Corticospinal tract is concerned specifically with discrete voluntary skilled movements, especially of the distal parts of the limbs. – Wiki

“motor system which is used to make conscious movement.

What is pyramidal pattern weakness?

Mm weakness with anti-gravity muscles (extensors of the lower limb & flexors of the upper limb) are spared. Pt can develop posture of flexed & pronated arms with clenched fingers & extended & abducted legs w plantar flexion of the feet - Turner

Extra Pyramidal SystemGenerally speaking what is the Extra Pyramidal system?

Extrapyramidal tracts are mainly found in the Reticular Formation of the pons and medulla, The system is called "extrapyramidal" to distinguish it from the tracts of the motor cortex

What is the function of the extra pyramidal system ?

reflexes, locomotion, complex movements and postural controlExtra Pyramidal tracts are background helpers

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Name the Extra Pyramidal Tracts

ROVeR

Reticulospinal (sets mm tone via the spindles)Rubrospinal (It is one of the pathways for the mediation of voluntary movement. Responsible for large and fine movement. Originates from red nucleus to midbrain) terminates in the CSp which suggests it is used in control of the UEx but not LEx)OliviospinalVestibulotract

How do Extrapyramidal disorders present?

As more or less UMNL Seen as movement disorders these days

What are the 2 categories of extra ExtraPyramidal Disorders?

Decreased Movement Increased Movement

Clinical features of Decreased Movement

Postural disturbance: failure to make quick postural adjustments. Patient often falls. Flexion of limbs and trunk is associated with this

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Bradykinesia: a loss or slowness of voluntary movementMask like faceReduced blinkingReduced adjustments of posture when sitting

Clinical features of Increased Movement

MR T BCD

Myoclonus (shock like jerks)Rigidity – stiffness of limbs (During passive movement can be felt throughout the ROM & equally in flexors & extensors = Plastic/Lead Pipe Rigidity)Tremor

Ballisimus (explosive, violent movements)Chorea (repetitive, irregular, jerking movements)Dystonia (slow, sustained, abnormal voice)

Whats the most common eg of Ext Pyrmd Disease?

Parkinsons

PARKINSONS DISEASEPathology Progressive degeneration of cells within the pars compacta of Substantia Nigra in the midbrain- causing a loss of

dopamine. Disorder of basal ganglia What is Substantia Nigra? Latin for “Black substance”. Appears dark due to high levels of melanin in dopaminergic neurons. It’s a brain

structure located in the mesencephalon (midbrain) that plays an important role in reward, addiction & movement. Parkinson's disease is characterized by the death of dopaminergic neurons in the substantia nigra pars compacta.

Aetiology Cause unknown. Possibly geneticClinical Features

BRiT

Classic triad of Bradykinesia (especially decreased ability to start & continue movements) Rigidity i

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Tremor& associated changes in posture and gait

Signs

PS DRHR

Pill rolling tremorSpidery, small handwriting

Difficulty starting movements Resting tremor (especially early in the morning)Hypertonia (Cogwheel type – timed jecky)Rigidity – stiffness of limbs (During passive movement can be felt throughout the ROM & equally in flexors & extensors = Plastic/Lead Pipe Rigidity). Passive movements are jerky

Symptoms Symptoms asymetrical to begin with (if symmetrical its unlikely that they have parkinsons)

Face is like a mask – unexpressive. Reduced blinking Voice quiet & monotonous - think of muhammed ali Gait- stiff, shuffling Speech – monotonous, hypophonic dysarthria due to a combination of bradykinesia & rigidity and tremor Depression

What will their reflexes be like?

Increased

Therapy Walking on paper or Counting steps: uses conscious movement – tiring. uses pyramidal system (corticospinal tract)Drugs (attempting to restore dopamine levels) only work for a short period of time

What is chorea? Involuntary, irregular, jerking, movement affecting limb and axial muscles. These movements can be suppressed with difficulty (resulting in semi-purposeful appearance eg. Crossing and uncrossing of legs)

What can cause it Huntington’s, Hyperthyroidism, Hypocalcaemia, SLE, PANWhat is Huntington’s Disease?

Heriditary condition characterised by personality changes and movement disorders

What is Hemiballismus? Movement characterised by unilateral, violent flailing of the limbs. Involuntary movement is occasionally severe enough to throw the patient off balance

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What can cause it Caused by infarction or haemorrhage in the conralateral subthalamic nucleus - turner

Vascular diseaseMultiple Sclerosis

Prognosis Drug TTT is ineffective the condition often settles spontaneously

What are Tics? A brief contraction of a muscle or group of muscles. Simple tics (eg. Twitching of eyelids)Complex tics are: abrupt, transient, coordinated movements or vocalisations.. Can be voluntarily suppressed & often takes the form of winking, grimacing, shoulder shrugging, sniffing & throat clearing. Characterised by Giles de la Tourette Syndrome

Giles de la Tourette Syndrome

Sudden occurrence of multiple motor tics accompanied by sudden explosive grunting In ‘Tourette’s syndrome’ the basal ganglia are either no longer inhibiting or more likely

stimulating some of the vocal centres directly so that you get this string of scantalogical language

Differentiate between Pyramidal vs. Extrapyramidal structures + functions

Predict possible sources of confusion in relation to UMNLOutline of management strategies: what do you tell the patient?

Give an overview of their part in the control of movement and gaitDescribe Parkinsonism, choreo-athetosis, hemibalismus, tics

Describe (explain?) typical features of extrapyramidal dysfunction

http://www.aecc-spinecentre.co.uk/products/books--dvds-49/

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