Movement disorders Flashcards
What two systems control movement?
Describe what they do briefly.
Pyramidal: control of conscious movement
Extrapyramidal: unconscious control of tone and posture, maintains centre of gravity
What is the difference between the pyramidal and extra-pyramidal system?
Pyramidal:
- neurons travel through the pyramids of the medulla
- control of conscious movement
Extrapyramidal:
- don’t travel through pyramids of medulla
- unconscious control of tone, posture and centre of gravity
Describe how the extrapyramidal system works?
Modulation and regulation of the anterior horn cells
To maintain posture and centre of gravity
What is dystonia?
A name for a number of types of muscle disorder
Distortion of posture or repetitive movements caused by prolonged spasms of muscle contraction
The muscle holds the body part it supplies in a fixed position
For example the neck is fixed in a looking down position
When does dystonia usually start?
After adolescence
What is geste antagonistique?
Sometimes, when the patient touches the muscle affected with dystonia the symptoms are relieved
What types of dystonia are there?
Idiopathic generalised dystonia
Focal dystonia
Writer’s cramp
Acute dystonia
What is writer’s cramp?
Affects people who write a lot
Postural distortion of the hand, for example a finger extending abnormally when writing
It is limited to certain movements of the body, so writing only
What is idiopathic generalised dystonia?
Dystonia affecting one muscle, such as one in the leg, the dystonia spreads over many years
What is focal dystonia?
Dystonia confined to one part of the body, i.e. the neck
What are muscle spindles?
Sensory receptors within a muscle that detect changes in the length of this muscle
They convey length info to the CNS via sensory neurons.
This information can be processed by the brain to determine the position of body parts
Management of dystonia?
Botox can temporarily weaken muscles and reduce spasm
Medication:
- anti-cholinergics
- muscle relaxants
Surgery if no other methods are sucessful
What is parkinsonism?
When people have Parkinson features but not actual Parkinson’s disease
It is usually asymmetric and does not respond to Parkinson medication
What are the features of parkinsonism?
Bradykinesia
Rigidity
Tremor
PLUS
Gait apraxia
Autonomic features
What is bradykinesia?
Extreme slowness of movements and reflexes
What does apraxia mean?
A disorder of sequencing movements
A loss of the ability to perform complex co-ordinated movements, such as dressing
What would gait apraxia look like?
Difficulty walking, poor balance, shuffling, shaky walking
What causes Parkinsonism?
Toxins
Metabolic diseases
Some neurological conditions
Vascular parkinsonism
But not Parkinson’s
What is the purpose of CSF?
It stops you getting a gait apraxia
When blood enters the brain, some fluid has to leave, otherwise pressure would rise in the brain causing damage
When blood enters, CSF squirts out of the foramen magnum, meaning inter-cranial pressure stays constant
What is vascular parkinsonism?
Gait apraxia caused by normal pressure hydrocephalus
Mainly affects lower half of body
Likely caused by basal ganglia ischaemia
What is normal pressure hydrocephalus?
With age, and with some other conditions there is an impairment of the ejection of CSF out of the cranium as arterial blood enters
Pressure builds up = hydrocephalus
What does chorea mean?
A type of dyskinesia
Brief, irregular movements that are not repetitive or rhythmic,
Appear to flow from one muscle to the next
What causes chorea?
Huntington’s Chorea
Wilson’s disease (excess copper)
Rheumatic fever
Many more
What does dyskinesia mean?
Umbrella term for abnormal involuntary movements
What does athetosis mean?
Slow, purposeless, involuntary movements
Often caused by cerebral palsy
What types of tremors are there?
Postural
Intention
Rest
What causes postural tremors?
Muscle spindle problem
What causes resting tremors?
Basal ganglia disease, like Huntington’s, Parkinson’s
What is myoclonus?
Sudden involuntary focal or general jerks arising from the CNS
This has many causes, but most often it is benign
What is akathasia?
A feeling of restlessness, inability to stay still
What is hemiballismus?
Large amplitude, flinging movements on one side of the body
Arm hits the body
Contralateral to the lesion
What is a tic?
Brief, repeated movements
Like winking, arm movements, pulling faces
Describe what a tic disorder feels like?
A build up of a compulsion to do the movement
You can’t resist it so you have to do the movement
Then the compulsion goes away
But it begins building up again
