Week 18 - Nervous System Flashcards
What type of motor neuron lesion causes hyperreflexia?
Upper motor neuron lesion
What is Parkinson’s disease?
Progressive reduction in dopamine in the basal ganglia leading to disorders of movement
What is the typical patient of Parkinson’s?
Man around aged 70
Gradual onset of symptoms
What is the classic triad of symptoms for Parkinson’s?
Resting tremor
Rigidity
Bradykinesia
What is myasthenia gravis?
Autoimmune condition affecting NMJ
Causes muscle weakness that gets progressively worse with activity and improves with rest
How do you elicit fatigability of muscles?
Repeated blinking -> ptosis
Prolonged upward gazing -> exacerbate diplopia
Repeated abduction of 1 arm -> unilateral weakness
What is the typical patient of motor neuron disease?
60 year old man with an affected relative
What are 4 common signs of lower motor neuron disease?
Muscle wasting
Reduced tone
Fasciculations
Reduced reflexes
What are 3 common signs of upper motor neuron disease?
Increased tone/spasticity
Brisk reflexes
Upgoing plantar reflexes
What drug can extend survival and slow progression of MND?
Riluzole
What are the common causes of death in MND?
Respiratory failure
Pneumonia
What is multiple sclerosis?
Autoimmune condition involving demyelination in central nervous system
What is a typical patient of MS?
Young adult
More likely women
What are key features of optic neuritis?
Enlarged central blind spot (central scotoma)
Pain with eye movement
Impaired colour vision
Relative afferent pupillary defect
When is optic neuritis seen?
Multiple sclerosis
What is ataxia?
Problem with coordinated movement
What is sensory ataxia and in what test is it positive?
Loss of proprioception
Results in a positive Rombergs test = lose balance when standing with eyes closed
What lesion causes sensory ataxia?
Lesion in the dorsal columns of the spine
Which parts of the visual field do not cross at the optic chiasm and which do?
Lateral aspects of vision don’t cross
Medial aspects of vision do cross
Which tract transports information about vibration, proprioception and fine touch?
Dorsal column
What information is carried in the dorsal column?
Sensory
- Proprioception
- fine touch
- vibration
What are the 2 regions of the dorsal column and where do they carry information from?
Fasciculus gracilis = more medial, info from below T6-T8
Fasciculus cuneatus = more lateral, info from above T6-T8 but below the head
What information is carried by the spinothalamic tract?
Sensory
- crude touch
- pressure
- pain
- temperature
What tract transmits info on pain, temperature, crude touch and pressure?
Spinothalamic
At what level do nerve fibres cross over in the spinothalamic tract?
At the level the spinal nerve enters
What type of tract is the corticospinal tract?
Motor - pyramidal
What is the function of a pyramidal tract?
Conscious control of muscles from the cerebral cortex to the muscles of the body and the face
What is the function of extrapyramidal tracts?
Unconscious, reflexive or responsive control of muscles from various brain stem structures
What 3 major cortical areas does the corticospinal tract communicate with?
Primary motor cortex
Premotor cortex
Supplementary motor cortex