CNS (tutorial) Flashcards
What are the 2 questions you ask yourself when presented with a patient with a neurology case?
Where is the lesion?
What is the lesion?
What are the divisions of the spine?
Where on the back is it safest to draw spinal fluid out of?
Where the nerves part - at the lower back
Feel hips, draw line across back
Left side of the brain co-ordinates the right, right side of the brain co-ordinates the left, but where does this switch?
Mainly in the medulla (part of the brain stem)
For some sensory neurones lower down the spine
Where does movement for the legs come from?
Motor neurons from the frontal lobe
How can you tell if it’s the brain, spine or leg that has a lesion?
Brain = affects whole of the one side
Spine = affects e.g. lower half
Leg = localised? idek
Where are the sensory and motor neurons located in the brain?
Motor = front slice
Sensory = back slice
What are the 2 tracts that take sensation up from the feet to the brain?
Dorsal columns (touch)
Spino-thalamic (pain centre)
What is the corticospinal tract?
What is the corticobulbar tract?
Motor pathway from the cerebral cortex, controls movement of limbs and trunk
Motor pathway to control movements of the head and neck
Where does the spinothalamic neuron cross?
Different to motor neurons
Crosses lower down the spinal cord
Which tract does pain and temperature travel up? Where does it cross?
Spinotholamic
Lower down the spine
Which tract does touch travel up?
Dorsal columns - go to the sensory cortex
Cross in the medulla
Where do the dorsal columns and corticospinal tracts cross?
Medulla
Which nerves recover better? (PNS or CNS)
PNS much better than the CNS
Requires reconnecting of the nerves
Where are the motor and sensory strips in the brain?
25M - fell from scaffolding, fractured his spine in the mid-thoracic region. No movement in the right leg and proprioception and sensation for touch was impaired below T10 on the right. He could feel pain and temperature in his right leg. His left leg moved normally, had normal touch sensation but retained no sensation for pain or temperature.
- What is the site and extent of the lesion?
- Explain the pattern of symptoms in neuroanatomical terms:
- Is he likely to recover the lost movement and sensation?
- One sided fracture on the right, under T10 - 3 tracts affected: one motor (corticospinal) and 2 sensory tracts (dorsal column and spinothalamic)
- The motor neuron, corticospinal, crosses at the medulla, hence the right leg cannot move.
The sensory neurons, spinothalamic and dorsal columns, cross lower down the spine, hence the left leg has no pain or temperature sensations - Generally PNS nerves recover much better than CNS nerves - requires rejoining / reconnecting of the nerves.
V. unlikely, the patient is unlikely to ever walk again
75F - had a stroke, the immediate signs were moderate weakness and loss of sensation in the left hand and forearm. During the following weeks the weakness and sensory disturbance resolved, but periodically she had strange sensations in his left hand, such as sudden coldness or feeling of increased pressure. Occasionally the feeling spread up her arm and sometimes these episodes were accompanied by jerking movements of the arm, which she could not control.
- What was the location of the infarct that led to the initial stroke symptoms?
- What are the strange sensations and jerking movements a sign of?
- What treatment could be given to reduce or prevent these involuntary movements?
- What is likely to happen if the condition is left untreated?
- On the right side of the brain - in the primary motor and the sensory strips
- Originating from same area - in the primary motor and the sensory strips. Scarring - it is epilepsy due to the electrical spread (partial seizure)
- Usually give: Diazepam - immediately to stop seizures
Long-term - other medication - It can lead up to a generalised seizure (get bigger)
