Session 1.1c - Group Work Flashcards
Case 1
A patient fell out of bed in the night, and you have been called by a nurse to check that they are OK. They seem orientated and alert and state that they did not suffer any injuries. They are not complaining of any pain or headache. You carry out a neurological examination and discover that they have bilaterally absent knee jerk reflexes.
Which structures detect muscle stretch when the tendon hammer is applied to the patellar ligament?
Stretch receptors within the muscle spindle
Golgi tendon organs - stretch receptors in the tendon
Case 1
A patient fell out of bed in the night, and you have been called by a nurse to check that they are OK. They seem orientated and alert and state that they did not suffer any injuries. They are not complaining of any pain or headache. You carry out a neurological examination and discover that they have bilaterally absent knee jerk reflexes.
What is the generic term for the neurone that receives information from the structures named above?
Sensory afferent
Case 1
A patient fell out of bed in the night, and you have been called by a nurse to check that they are OK. They seem orientated and alert and state that they did not suffer any injuries. They are not complaining of any pain or headache. You carry out a neurological examination and discover that they have bilaterally absent knee jerk reflexes.
What is the generic term for the neurone that sends impulses to the skeletal muscle in a reflex arc?
Motor efferent
Case 1
A patient fell out of bed in the night, and you have been called by a nurse to check that they are OK. They seem orientated and alert and state that they did not suffer any injuries. They are not complaining of any pain or headache. You carry out a neurological examination and discover that they have bilaterally absent knee jerk reflexes.
In monosynaptic reflexes like the knee jerk, where is the synapse found?
Synapses in the dorsal horn which relays to the ventral horn to produce the ventral motor action.
Case 1
A patient fell out of bed in the night, and you have been called by a nurse to check that they are OK. They seem orientated and alert and state that they did not suffer any injuries. They are not complaining of any pain or headache. You carry out a neurological examination and discover that they have bilaterally absent knee jerk reflexes.
Draw a labelled diagram showing the complete reflex arc.
See print screen of video
Case 1
A patient fell out of bed in the night, and you have been called by a nurse to check that they are OK. They seem orientated and alert and state that they did not suffer any injuries. They are not complaining of any pain or headache. You carry out a neurological examination and discover that they have bilaterally absent knee jerk reflexes.
What spinal level(s) mediate(s) the knee jerk reflex?
L3
Case 1
A patient fell out of bed in the night, and you have been called by a nurse to check that they are OK. They seem orientated and alert and state that they did not suffer any injuries. They are not complaining of any pain or headache. You carry out a neurological examination and discover that they have bilaterally absent knee jerk reflexes.
List as many reasons that you can think of for why you were unable to elicit knee jerk reflexes in this patient.
- Damage to dorsal and/or ventral horn lesion
- Spinal cord lesions
- Cauda equina
- Nerve conduction problems e.g. MS
- Spinal disc prolapse
- Spondylolithesis
- Asleep
- Essential tremors
- Haven’t got legs
Case 1
A patient fell out of bed in the night, and you have been called by a nurse to check that they are OK. They seem orientated and alert and state that they did not suffer any injuries. They are not complaining of any pain or headache. You carry out a neurological examination and discover that they have bilaterally absent knee jerk reflexes.
Watch this video giving an explanation of the Jendrassik manoeuvre. Speculate on how you think it might work. (Note that when you see the word ‘speculate’ in a question you are not expected to have specific knowledge of a system at this stage, but to use the knowledge that you already have to come up with some sensible ideas)
https://www.youtube.com/watch?v=Y6vZzG-DylE
- Central descending inhibition; to trick it, get them to concentrate on something else e.g. Jendrassik Maneuver, they’re not thinking about it so there’s less descending inhibition
Case 2
Whilst out shopping you witness a man collapse and start having a seizure. As a medical student you attend to the man during the interval before an ambulance arrives.
You notice that the man’s seizure started in his left hand, but then progressively moved proximally through his upper limb. Why is this the case?
A seizure is caused by a spontaneous, uncontrolled, involuntary firing of neurones. In this case, it began in the hand area of the homonculus, but then as the neurones propagate into adjacent neurones in the next homunculus region, which is moving proximally through his upper limb.
Case 2
Whilst out shopping you witness a man collapse and start having a seizure. As a medical student you attend to the man during the interval before an ambulance arrives.
In which side of the brain is there likely to be an abnormality? Speculate on which CNS pathways are likely to cross over
The contralateral side (i.e. right side of the brain for left hand) due to the decussation of the medullary pyramids.
Case 2
Whilst out shopping you witness a man collapse and start having a seizure. As a medical student you attend to the man during the interval before an ambulance arrives.
The man’s seizure subsides and the ambulance takes him to hospital. You are in the Medical Assessment Unit a couple of days later, when you encounter the man again. He seems well, and asks you if you know the result of his MRI scan, part of which is shown below.
What is a T1 MRI scan, and how does it differ from a T2 scan?
T1 makes water black, fat white
T2 makes water white, fat dark
(Terminator 1 - bad guy
Terminator 2 - good guy)
[Gd = MRI contrast]
Case 2
Whilst out shopping you witness a man collapse and start having a seizure. As a medical student you attend to the man during the interval before an ambulance arrives.
The man’s seizure subsides and the ambulance takes him to hospital. You are in the Medical Assessment Unit a couple of days later, when you encounter the man again. He seems well, and asks you if you know the result of his MRI scan, part of which is shown below.
Describe what can be seen. What might it be, and which tissue might it derive from?
There is a tumour around the right central gyrus (between temporal and parietal lobe), and one of the properties of tumours/neoplasia is angiogenesis hence the vascular appearance (i.e. fluid-filled).
Meninges may be deriving this tumour.
Case 2
Whilst out shopping you witness a man collapse and start having a seizure. As a medical student you attend to the man during the interval before an ambulance arrives.
The man’s seizure subsides and the ambulance takes him to hospital. You are in the Medical
Assessment Unit a couple of days later, when you encounter the man again. He seems well, and asks you if you know the result of his MRI scan, part of which is shown below.
Why does gadolinium (Gd) enhance the lesion?
Gd enhances the contrast because it is highly vascular.
Case 2
Whilst out shopping you witness a man collapse and start having a seizure. As a medical student you attend to the man during the interval before an ambulance arrives.
The man’s seizure subsides and the ambulance takes him to hospital. You are in the Medical
Assessment Unit a couple of days later, when you encounter the man again. He seems well, and asks you if you know the result of his MRI scan, part of which is shown below.
Which structures in the cerebral hemisphere is the lesion compressing?
It is compressing the ventricles, which is the only thing that can be compressed because it is fluid-filled.
Case 2
Whilst out shopping you witness a man collapse and start having a seizure. As a medical student you attend to the man during the interval before an ambulance arrives.
The man’s seizure subsides and the ambulance takes him to hospital. You are in the Medical
Assessment Unit a couple of days later, when you encounter the man again. He seems well, and asks you if you know the result of his MRI scan, part of which is shown below.
Speculate on what might happen if the lesion continues increasing in size.
This can lead to eventual herniation of the tumour into the foramen magnum, leading to coning.
