Week 5 - C - Spinal cord compression, Tracts, Acute - Transection, Anterior/posterior/central cord syndrome - Chronic Tx Flashcards
What is the main sensory tracts of the spinal column and the main motor tract of the spinal colum?
The main sensory tracts of the spinal column are: * The dorsal column medial lemniscus * The spinothalamic tract (anterolateral system) These are both ascending tracts The main motor tract of the spinal colum is the corticospinal tract - this is a descending tract
How many neurones does the corticospinal tract consist of? Describe the course of the corticospinal tract? Where does the syanapse occur in the corticospinal tract?
The corticospinal tract is a two motor neurone tract The neurones start in the precentral gyrus of the posterior frontal lobe where they travel through the internal capsule and down to the medulla where 85% of the fibres decussate - this is known as the lateral corticospinal tract The other 15% of the fibres continue to travel in the anterior grey horns of the spinal cord before decussating at the level of which they supply. The synapse for both anterior & lateral occurs in the anterior grey horns cells of the spinal cord level they supply - now becoming a LMN
What is the function of the corticospinal tract? What would it mean if i were to say the corticospinal tract was an ipsilateral tract?
The function is provide fine precise movement to the limbs and axial skeleton As the majority (85%) of fibres decussate in the medulla, the tract is said to be ipsilateral - this means that the motor neuron from (anterior grey horns of) spinal cord to the medulla are run ipsilaterally Damage to left side of spinal cord will impair movement on left side of body
Where would an upper motor neurone lesion arise? What would the signs of an upper motor neurone lesion be? (tone, reflexes, fasciculations, clonus, weakness)
An upper motor neurone lesion would arise anywhere between the precentral gyrus of the brain and the anterior horn cells of the spinal cord (grey matter) Signs * Tone - increased * Reflexia - hyperreflexia and extensor plantar reflex (babinski) * Fasciculations - absent * Clonus - present * Weakness - pyramidal weakness
What is clonus? What is the pyramidal weakness seen in upper motor neuron lesions? Does UMN lesions effect single muscles or muscle groups?
Clonuc is the involuntary, successive cycles of contraction and relaxation of a muscle Pyramidal weakness is where there is weakness in the extensors of the upper limb and the flexors of the lower limb Upper motor neurone lesions affect muscle groups (as above) whereas lower motor neurone lesions affect single muscles that they innervate
Is muscle wasting seen in upper or lower motor neurone elsions? What are the signs of a lower motor neurone lesion? What do lower motor neurone lesions affect?
Muscle wasting is seen in predominantly in lower motor neruone lesions The signs of a LMN lesions * Tone - hyporeflexia * Reflexes - diminished * Fasciculations - present * CLonus - absent * Weakness - of individual muscles supplied, wasting LMNs affect the spinal cord or the peripheral nerve
What is the function of the spinothalamic tract? Where is it said to decussate and therefore is it contra or ipsilateral?
The function of the spinothalamic tract is for the sensation of - crude touch and pressure (anterior) - temperature and pain (lateral) The spinothalamic tract is said to decussate in the spinal cord, a couple of levels above the entry usually, and therefore it is a a contralateral tract (spinal cord to medulla is contralateral to the side of entry)
What is the function of the dorsal column medial lemniscus? Where is it said to decussate and therefore is it contra or ipsilateral?
The dorsal column medial lemnsicus carries fine touch, proprioception and vibration It is said to decussate in the medulla and therefore is considered an ipsilateral tract
Spinal cord compression: * Acute or Chronic * Complete or Incomplete What can acute spinal cord compression arise due to? WHat is the commonest cause of spinal cord compression?
Acute spinal cord compression - usually arises due to * Trauma * Tumours * Infection * Spontaneous haemorrhage Commonest cause of spinal cord compression is malignant compression of the spinal cord
What are some causes of chronic spinal cord compression?
Degenerative diseases ie spondylosis Tumours Rheumatoid arthritis
What were the different causes of acute compression again? The presentation of acute compression can differ dependent on whether the whole cord is compressed or only partially (incomplete) If there is a complete transection or compression of the cord, what will this cause?
Acute cord compression * Trauma * Tumours * Infection * Spontaneous haemorrhage Complete compression of the cord symptoms Bilateral paralysis below the level of compression Bilateral loss of sensation below the level of compresion - loss of crude touch, pressure, pain, temperature & fine touch, vibration and proprioception
How does a complete cord compression present initially?
Initially, there is a flaccid areflexic paralysis - this is known as spinal shock The upper motor neurone lesion signs then appear later
What signals the end of the spinal shock period? How long can this take to occur?
When the features of an upper motor neurone lesion kick in ie stops being flaccid areflexic paralysis and hyperreflexia and spasticity begin Duration is not predicatable - can take months
The absence of the bulbocavernosus reflex without sacral spinal cord trauma indicates spinal shock How is the bulbocavernosus reflex initiated normally? What nerves are tested here? Polysynaptic reflexes such as this are usually the first to return in spinal shock
Bulbocavernosus reflex - bulbocaverosus reflex refers to anal sphincter contraction in response to squeezing the glans penis or tugging on the Foley catheter (squeezing causes sensory pudendal fibres to relay to cord and the reflex causes motor pudendal fibres to activate clenching the anal sphincter) Absence indicates spinal shock
What is the condition where there is a cord hemisection known as? What are the features of this condition?
Cord hemisection = Brown-Sequard Syndrome
Below level of hemisection:
- Ipsilateral paralysis (corticospinal tract)
- Ipsilateral loss of fine touch, vibration and proprioception (DCML)
- Contralteral loss of crude touch, pressure, pain and temp (spinothalamic tract)
What defects does a patient present with in central cord syndrome?
Due to the central cord syndrome meaning there is a problem with the central area of the cord, the patients upper limbs and axial skeleton tend to be far greater affected than the less/non affected lower limbs * The DCML (fine touch, vibration, proprioception) and the lower limbs - relatively spared in the condition Patients usually present with loss of pain and temperature as well as weakness in the upper limbs and chest - bilaterally Almost cape like spinothalamic and DCML loss
What does the anterior spinal artery supply in comparison to the posterior spinal artery?
The anterior spinal artery supplies the anterior 2/3rd of the spinal cord - the posterior spinal artery is what supplies the dorsal colums, dorsal horns The anterior spinal artery is a branch of the vertebral arteries joining together Posterior spinal arteries are branches of each vertebral artery
Tumours: Can slowly compress Can cause acute compression by collapse or haemorrhage If i said the picture was showing a tumour, what would most likely have cause the spinal cord compression and at what vertebral level?
The tumour is at the C7 vertebral level and the image shows it looks like the tumour has collapsed causing spinal cord compression - this would probably present acutely
This is an example of a benign tumour – it is intradural but extramedullary and is squashing the spinal cord at the level of C2 Because of its location, what could it cause in the patient?
Because it is at the C2 spinal level, it has the potential to stop the patient from breathing as C3,4,5 could be affected
WHat is facet joint hypertrophy?
Facet joints exist between the superior articular process of one vertebra and the inferior articular processes of another Facet joint hypertophy occurs when the joint is too big and can compress the spinal cord - usually due to degeneration and enlargement of the joint
