Week Seven - Movement Disorders Flashcards
What are the characteristic features of all movement disorders?
An abnormality of the form and velocity of movements of the body and are often associated with neuropsychological deficits
The term “movement disorder” has become synonymous with what?
The term “movement disorder” has become synonymous with basal ganglia disease and extrapyramidal features.
Why is it unsurprising that movement disorders are also frequently associated with cognitive and neuropsychiatric problems?
because of the extensive cerebral cortical connectivity of basal ganglia structures
Normal motor control requires maturation of what 2 systems?
musculoskeletal and NS
All the voluntary muscles of the body are directly innervated by what?
The motor neurons in the spinal cord and hindbrain.
What is not innervated by the motor neurons in the SC and hindbrain?
The muscles that activate the eye, which are innervated from midbrain nuclei
The control of voluntary movements has three stages, what are they?
Planning, initiation and execution, which are performed by different brain regions
What are alpha-motor neurons responsible for?
The execution of movements.
What brain areas are involved in planning movement?
cortical association areas and BG and cerebellum
What brain areas are involved in actual initiation of movement?
Motor cortex
What area of the brain is responsible for fine tuning movements?
Cerebellum
Movement is involved in a circuit -
The highest level of the hierarchy comprises many regions of the brain, including those associated with?
Memory, emotions and motivation.
The intent to ‘move’ is formed where?
In the highest level of the hierarchy, in the command neurons (typically, pyramidal neurons in the motor cortex).
Movement is involved in a circuit -
What occurs in the middle level?
Information is relayed to the middle level, which is located in the sensorimotor cortex of cerebral cortex, the basal ganglia of the subcortical nuclei, the cerebellum, and the brainstem.
Postures and movements required to perform the task are determined.
Receive input from receptors in the muscles, the joints, the skin, eyes
Creates a motor program, that defines the information required to perform the desired task.
What modulates activity in the middle level?
Feedback loops involving these independent subcortical systems (the cerebellum and the basal ganglia) modulate activity at the brainstem and cortical levels.
What can movement disorders be categorised into?
Akinetic-Rigid: move too little and Hyperkinetic: move too much
What do bradykinesia and hypokinesia refer to? (used interchangeably with akinetic)
Bradykinesia means ‘slow movement’
Hypokinesia refers to poverty of movement, or movements that are smaller in amplitude than that intended.
What term best captures the essence of PD?
Hypokinesia
Which type of movement disorders are harder to diagnose?
Hyperkinetic
What further subtypes have hyperkinetic movements disorders been broken down into?
jerky and non-jerky syndromes.
What do jerky syndromes comprise?
myoclonus, chorea, and tics
What do non-jerky syndromes comprise?
tremor and dystonia.
What is Myoclonus? (j)
Sudden, brief, shock-like involuntary movements which we may all experience on occasion when falling off to sleep.
What is Chorea? (j)
Quick, irregular, semi-purposive, and predominantly distal involuntary movements which can impart a “fidgety” look to the patient.
What are Tics? (j)
Abrupt, jerky, non-rhythmic movements (motor tics) or sounds (vocal tics) that are temporarily suppressible by will power. These movements are preceded by a feeling of discomfort or an urge that is temporarily relieved by the tic.
What are Tremors? (nj)
An involuntary, somewhat rhythmic, muscle contraction and relaxation involving oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements.
What is Dystonia? (nj)
An abnormal movement in which a person’s muscles contract uncontrollably. The contraction causes the affected body part to twist involuntarily, resulting in repetitive movements or abnormal postures.
What is PD defined as?
A progressive degenerative disorder of the CNS
What are the major symptoms of PD?
bradykinesia, temor and rigidity
What is the anchor feature of PD?
Bradykinesia
Walking characteristics of those with PD?
Slowed gait and the feet tend to shuffle along the floor as if weighted down
What happens to handwriting in those with PD?
Becomes small and imprecise