NMS 4 Flashcards
Briefly explain the role of the posterior ligamentous system (PLS) and how it protects the lumbar facet joints. (100%)
facet joint capsule
ligamentum flavum
interspinous ligament
supraspinous ligament
In particular, it acts to hold the facet joints of the neighbouring vertebrae in fixed relation with each other.
Injury of the posterior ligamentous complex can result in subluxation or dislocation of the face
Multiple Mononeuritis how to treat and prognosis?
Can be caused by cancer or HIV
Mr Smith has handed you a report from a magnetic resonance (MRI) scan. It describes a spondylotic cervical ‘bar’ at C4/5 spinal column level causing inter-vertebral foramen and spinal canal encroachment:
a. Briefly describe the changes in neurological structure that Mr Smith might have.
b. Describe - and if possible explain - any ‘inversion’ of reflexes that this might cause.
c. In addition, describe TWO symptoms and THREE further signs that would help you to assess the extent of neurological damage.
Foraminal encroachment means that degeneration in the spinal column has caused an obstruction of the foramina,
Nerve compression may occur by buckling of ligamentum flavum dorsally can cause direct compression
There is no tendon reflex tested for the C4 nerve. Damage to the C5 cervical nerve can cause diminished tendon reflexes of the biceps and brachioradialis muscles
Isaid to be present when the supinator (brachio)reflex elicits finger flexion and not elbow flexion
is associated with an absent biceps jerk and an exaggerated triceps jerk
Pain, Numbness or Paresthesia
Respiratory Difficulties
C4 and C5, along with C3, supply the diaphragm – the muscle that separates the chest and abdominal cavitie
Reflex Weakness
Specifically, the C4 nerve enervates the levator scapulae, trapezius and rhomboid muscles. Damage to the C4 nerve may result in difficulty in elevating the shoulders. The C5 nerve supplies the deltoid, supraspinatus, infraspinatus and biceps muscles. Damage to the C5 nerve can affect the ability to raise the arm or bend it at the elbow.
What are the key differences between peripheral nervous system (PNS) damage and central nervous system (CNS) damage? Include in your answer:
a. A brief account of key structural changes. (20%)
b. The distinctive symptoms that differentiate the two conditions. (30%)
c. The distinctive signs that differentiate the two conditions. (50%)
If the process of a neuron is not severed but loses its insolation (because oligodendrocytes in the CNS or Schwann cells in the PNS are damaged and die) then the signal will stop and attempts to regenerate the isolation sheet will start.
In the CNS immune and glial cells will react, but their signals are not supportive, debris of the isolation material needs a much longer time to be cleared, inhibiting repair mechanisms.
Oligodendrocytes do not rejuvenate, nor do they secrete growth factors. In fact, they secrete substances actively suppressing the formation of new processes. They receive support from astrocytes which also secrete inhibitory substances. Worse still, the normally universally helpful astrocytes build an obstacle at the site of injury: a dense scar, which is nearly impossible to penetrate for young neuronal processes
CNS - loss of pain/temp/vibration
PNS - patch of skin loss of sense
CNS - Pathological reflexes - Babinski/HOffmans sign
CNS- Hyper reflexia
PNS - hyporeflexia
Briefly detail the innervation of a typical lumbar vertebral segment and explain how irritation to the postero-lateral aspect of the intervertebral disc on one side can give symptoms on the other.
The posterior aspects of the discs and the posterior longitudinal ligament are innervated by the sinuvertebral nerves.
The posterolateral aspects of the discs receive branches from adjacent ventral primary rami and from the grey rami communicantes near their junction with the ventral primary rami.
The lateral aspects of the discs receive other branches from the rami communicantes. Some rami communicantes cross intervertebral discs and are embedded in the connective tissue of the disc deep to the origin of psoas.
Show how you would attempt to differentiate between lesion of L5 spinal nerve and the peroneal nerve. Include information in your answer under the following headings:
Past history Presenting complaints / symptoms Observable signs Motor examination Sensory examination Any further differential diagnostic information of your choice
In so called ‘obvious or classic” cases of L5 radiculopathy there will be lumbago, sciatic scoliotic list, glutalgia, posterior thigh and calf pain, alteredL5 distribution sensation and a restricted SLR and wasting of EDB
So, weakness of ankle dorsiflexors, toe extensors and ankle EVERTORS is suggestive of a PERONEAL NERVE lesion.Patients wit an L5 RADICULOPATHY will have similar deficits as those with a COMMON PERONEAL NERVE lesion- HOWEVER, the tibialis posterior (a primary ANKLE INVERTOR) is supplied by L5 THROUGH the TIBIAL NERVE SO WILL BE SPARED IN A COMMON PERONEAL NERVE lesion BUT IT WILL BE INVOLVEDIN AN L5 RADICULOPATHY(WITH WEAKNESS OF ANKLE INVERSION).THIS IS THE ANSWER!.
If there is altered sensation strictly defined in the 1st & 2nd toe webspace (with predominant weakness of ankle DF and toe extension than eversion, then this suggests a DEEP PERONEAL NERVE lesion over L5 Radiculopathy which usually involves a more extensive area of sensation medial and dorsal foot.
So, weakness of ankle dorsiflexors, toe extensors and ankle EVERTORS is suggestive of a PERONEAL NERVE lesion.Patients wit an L5 RADICULOPATHY will have similar deficits as those with a COMMON PERONEAL NERVE lesion- HOWEVER, the tibialis posterior (a primary ANKLE INVERTOR) is supplied by L5 THROUGH the TIBIAL NERVE SO WILL BE SPARED IN A COMMON PERONEAL NERVE lesion BUT IT WILL BE INVOLVEDIN AN L5 RADICULOPATHY(WITH WEAKNESS OF ANKLE INVERSION).THIS IS THE ANSWER!
What are the differences between the presentations of intrinsic cord damage and extrinsic cord damage? Include in your answer:
a) A brief account of the structural changes in the cord itself. (33.3%) b) Key distinctive symptoms that differentiate the two conditions. (33.3%) c) Key distinctive signs that differentiate the two conditions. (33.3%)
Spinal cord disorders usually result from conditions extrinsic to the cord, such as the following:
Compression due to spinal stenosis Herniated disk Tumor Abscess Hematoma
Intrinsic disorders include spinal cord infarction, hemorrhage, transverse myelitis, HIV infection, poliovirus infection
How would you examine them in order to differentiate between the following two servicemen’s presentations?
a) Captain Arthur has spinal cord compression resulting from spondylosis at C5/6 spinal level. (50%) b) Sergeant John has spinal nerve compression resulting from spondylosis at C5/6 spinal level. (50%)
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A - Paralysis of legs, wrists, and hands
Weakness of shoulder abduction and elbow flexion
Loss of biceps jerk reflex
Loss of brachioradialis deep tendon reflex
B - A C5-C6 disc herniation can cause weakness in the biceps (muscles in the front of the upper arms) and wrist extensor muscles. Numbness and tingling along with pain can radiate to the thumb side of the hand.
