Neuro (spinal cord) Flashcards
Why are lumbar punctures aimed below L2?
- Spinal cord end at L1-L2 with conus medullaris
- Aim below L2 to miss spinal cord
What are the important sensory (ascending) tracts?
- DCML
- Spinothalamic
- Dorsal horn
What is the DCML tract responsible for?
Vibration, soft touch, proprioception
What its the DCML cutaneous pathway responsible for?
- Vibration, soft touch and proprioception of the upper limbs
What is the DCML gracilis pathway responsible for and where is it in relation to the cutaneous pathway?
- Vibration, soft touch, proprioception of lower limbs
- Medial to DCML cutaneous
Where does the DCML decussate?
In the medulla
What is the ventral spinothalamic tract responsible for?
Crude touch
What is the dorsal spinothalamic tract responsible for?
Pain and temperature sensation
Where does the spinothalamic tract decussate?
White anterior commissure of spinal cord
What are the important motor (descending) tracts?
Corticospinal tract
What is the ventral corticospinal tract responsible for?
Trunk, neck and shoulders movement
What is the lateral corticospinal tract responsible for?
Limb movement
An acute onset spinal cord lesion suggest what aetiology?
- Trauma (e.g. knife wound, Brown sequard)
- Vascular (spinal cord stroke)
A subacute onset spinal cord lesion suggests what aetiology?
- Inflammation (e.g. MS, devics)
- Infection (e.g. asbcesss, Lyme)
A chronic onset spinal lesion suggests what aetiology?
- Cervical spondylosis
- Tumour
- Syringomyelia
- B12 deficiency
What are some intrinsic causes of spinal cord lesions?
- Transverse myelitis
- B12 deficiency (SADC)
- Spinal ischaemia
- Intraspinal neoplasm
- Hereditary spastic paraplegia
What is transverse myelitis and what are some examples?
- Inflammation of spinal cord
- MS
- Neuromyelitis optica (devics)
- Infection (viral, bacterial, Lyme)
What must be assumed in any force that results in loss of consciousness?
Cervical spine injury until proven otherwise
What are the 2 most common sites of spinal cord injury?
Cervical spine followed by thoracolumbar junction
What are some A-E considerations in spinal cord injury relating to airway?
- Can’t do head tilt, chin lift
- Laryngeal stimulation can cause massive vagal response (e.g. when intubating)
- This can cause cardiac arrest
- Give atropine before securing airway to prevent
What are some A-E considerations in spinal cord injury relating to breathing?
- Intercostal muscle paralysis or phrenic nerve paralysis can occur
- More proximal = worse
- C3, 4, 5 are phrenic nerve roots (C3, 4, 5 keep the diaphragm alive)
- Intercostals = t1 ro 11
What are some A-E considerations in spinal cord injury relating to circulation?
- Neurogenic shock can occur at level above T6
- Careful with resus as can cause acute pulmonary oedema
- Can diet and get hypothermia
What is the gold standard investigation for cervical spinal cord injury?
CT cervical spine
What are the features of complete spinal cord section?
- Complete sensorimotor loss below the level
- UMN signs and radicular pain at the level
What are the features of spinal cord hemisection (Brown-Sequard)?
Ipsilateral:
- UMN signs at level
- LMN signs, dorsal column loss (vibration, soft touch, proprioception) and spinothalamic (pain, temperature, crude touch) loss below the level
Contralateral:
- Spinothalamic (pain, temperature, crude touch) loss 2 levels below
What is a syringomyelia?
- CSF buildup in anterior commissure of spinal canal (syrinx)
- Most commonly between C3-C7
What are the features of syringomyelia?
- Cape-like distribution of loss of pain and temperature sensation (dorsal spinothalamic compression)
- Patients classically burn themselves and don’t notice
- Chronic onset
- UL weakness > LL weakness
What anatomical malformation is associated with syringomyelia?
Chiari malformation
What is an Chiari malformation?
Where the lower part of the brain pushes down into the spinal canal
What is a syrinx in the medulla called?
Syringobulbar
What investigation is used to investigate Chiari malformation?
MRI brain
What are the features of spinal cord infarct?
Acute onset back of neurological signs and back pain
At what level is a spinal cord infarct most likely to occur and why?
- T8
- Presence of artery of adamkiewicz
What are some causes of spinal cord infarct?
- Thromboembolic event
- Trauma
- Spinal surgery
- Cross clamping in non-spinal surgery
- Vasculitis
- Aortic dissection
What are the features of anterior spinal cord infarct?
Acute onset back pain and:
- Motor loss
- Spinothalamic (pain, temperature, crude touch) loss
What are the features of a posterior spinal infarct?
Acute onset back pain and DCML (soft touch, vibration, proprioception) loss
What investigations might help in diagnosing a spinal cord infarct?
- MRI spine
- Nerve conduction studies (rule out GBS)
- Look for cause (echo, coagulation, vasculitis and angiography)
How are spinal cord infarct treated?
As stroke
What is hereditary spastic paraplegia?
- An autosomal dominant cause of spastic paraparesis
- Results in bilateral lower limb UMN signs
What are the 2 types of HSP and what is the difference?
- Simple: just lower limb UMN signs
- Complex: LL UMN signs + ataxia + dementia
What are the typical ages of one for hereditary spastic paraplegia?
2 and 40 (i.e. young and middle age)
What is the management of hereditary spastic paraplegia?
Physio and baclofen
What are some causes of myelitis?
- MS or devics
- Systemic disease (e.g. Sjorgens, SLE, sarcoid, Behcets)
- Infection (viral, mycoplasma, syphilis and Lyme)
- Post vaccine immune response
What are features of myelitis?
- Subacute onset myopathy and radicular pain
- Takes months to settle
- Often only settles partially
- MRI shows SC swelling and oedema
What is the treatment for transverse myelitis?
- Dexamethasone for swelling
- Treat cause
What are the features of subacute degeneration of the cord?
- Distal sensory loss (mainly DCML)
- Proprioception and vibration loss can lead to ataxia
- Cord involvement cause MND features
- Dementia and widespread weakness in late disease
What are some causes of SADC?
- Anything that causes B12 loss
- Pernicious anaemia
- Ileal resection
- Tropical sprie
- IBD/coeliac
What is the management of SADC?
- B12 supplementation
- PN damage is curable
- SC damage is irreversible
What are some intramedullary spinal cord tumours?
- Glioma
- Astrocytoma
- Ependyoma
What are some extra medullary spinal cord tumour?
- Meningioma
- Neurofibroma
- Schwannoma
- Nerve sheath tumor
