NeURO: Part 7 Flashcards
Where does the cord end
L1/L2 (conus medullar is)
Where do we take lumbar puncture
L4
What is the Cauda Equina
Lumbar and sacral nerve roots
Define paraplegia
Paralysis of BOTH LEGS ALWAYS caused by spinal cord lesion
Define Hemiplegia
Paralysis of ONE SIDE of body caused by lesion of th brain
What side of the body do upper motor neurones effect
CONTRALATERAL to lesion
Where is a lesion in upper motor neurone located
ABOVE anterior horn cell (spinal cord, brainstem and motor cortex)
Signs of upper motor neurones
- SPASTICITY (increased muscle tone)
- Weakness
- Hyperreflexia
What is Spasticity
INCREASED Muscle tone where the faster you move, the greater the resistance
CLASP-KNIFE manner
Why is there weakness in upper motor neurone
Flexors are generally weaker than extensors in legs
Extensors are weaker than flexors in arms
In relation to the site of lesion, where are lower motor neurone signs seen (which part of th body)
IPSILATERAL to lesion
Where is lesion found in lower motor neurone disease
ANTERIOR horn cell or distal to anterior horn (plexus, peripheral nerve)
Signs of lower motor neurone disease
- DECREASED muscle tone
- WASTING (atrophy) + FASCICULATIONS
- Weakness that corresponds to muscles supplied by involved cord segment, nerve root, part of plexus or peripheral nerve
- HYPOREFLEXIA
What are FASCICULATIONS
Spontaneous involuntary twitching
What symptoms suggest a root problem in lower motor neurone disease
- Back pain + sciatica
What is sciatica
Pain radiating from the back to down th buttocks
What causes sciatica
Manual lifting (anything that causes lower back pain)
What suggests cord disease in lower motor neurone
Weakness of biceps with absence of biceps reflex
What suggests cord disease in upper motor neurone
Weakness of legs suggests lesion is below that level
Define spondylolisthesis
- Slippage of one vertebra over the one below
What nerve root is compressed in spondylolisthesis
Nevre root comes out ABOVE the disc and so root affected is the one BELOW disc herniation (L4/5 herniation leads to L5 root compression)
What is Olisthesis
Spondylolisthesis that shows displacement in any direction
What is anterolisthesis
Displacement anteriorly
What vertebra is affected in anterolisthesis
L5
What causes spondylolisthesis
- Degenerative anterolisthesis due to ligamentum flavour weakness and facet arthritis
What is the ligamentous flavour
Connect the laminae of adjacent vertebrae
Elasticity to preserve upright posture after flexion
Define spondylosis
Degenerative disc disease due to ANY disease
What causes spondylosis
YEARS of abnormal constant pressure (sports, repetitive trauma or poor posture) causing body to form new bone to distribute weight (pressure is being applied to vertebrae and discs between them)
What is a myotome
Group of muscles that is innervated by a single spinal nerve
What myotome is innervated by C5
Shoulder abduction/bicep jerk
What myotome is innervated by C6
Elbow flexion/supinator jerk
What myotome is innervated by C7
Elbow extension/triceps jerk
What myotome is innervated by L3/4
Knee extension/knee jerk
What myotome is innervated by L5
Ankle dorsiflexion
What myotome is innervated by S1
Ankle plantar flexion/ankle jerk
Define myelopathy
Compression of spinal cord resulting in upper neurone signs and symptoms dependant on where the compression is
What s the most common cause of acute compression
Vertebral body neoplasms
What causes vertebral body neoplasms
Secondary malignancy from lung, breast, prostate, myeloma and lymphoma
What happens to the disc in pathology
Herniation and prolapse
What happens in disc herniation
Centre of disc (nucleus pulpous) moves out through annulus (outer part of disc) = pressure on nerve root and pain
What happens in disc prolapse
Nucleus pulposus moves and presses against annulus but doesn’t escape outside annulus
Causes bulge in disc which pressures on nerve root = pain but less than herniation
What is an epidural abscess
Collection of puss in epidural space which presses on nerve root causing paralysis
What else can cause spinal cord compression
HAEMATOMA (warfarin)
TUMOUR
Clinical presentation of myelopathy
- Spinal or root pain precedes leg weakness and sensory loss
- Progressive weakness of legs CONTRALATERAL
- Signs of UMN: CONTRALATERAL spasticity and hyperreflexia
- Bladder sphincter involvement: hesitancy, frequency and painless retention
- SENSORY LOSS below level of lesion
- LMN signs AT level and UMN below level
Extra Clinical presentation seen in cervica cord lesion
ARM WEAKNESS
Clinical presentation in Sciatica
S1 NERVE ROOT COMPRESSOIN:
Sensory loss/pain in back of thigh/leg/lateral aspectt of little toe
Clinical presenttaion in L5 nerve root compression
Sensory loss/pain in lateral thigh/leg and medial side of big toe
Differential diagnosis of Myelopathy
- Transverse myelitis
- MS
- Cord vasculitis
- Trauma
- Dissecting aneurysm
How is myelopathy diagnosed
DO NOT DELAY IMAGING AT ANY COST
- MRI - gold standard
- BIOPSY/ SURGICAL EXPLORATION
- FBC
- CXR
Why should Imaging (MRI) be done straight away
Irreversible paraplegia may occur if cord is not decompressed
Role of MRI in myelopathy
Identifies cause and site of compression
Role of biopsy in myelopathy
Nature of mass
What would I be looking for in FBC
- ESr
- B12
- U+E
- Syphylis
- LFT
- PSA
Role f CXR in myelopathy
Malignancy or TB
Treatment of malignancy causing myelopathy
IV DEXAMETHASONE and radiotehrapy/chemotherapy
Role of IV DEXAMETHASONE
Reduces inflammation/oedema around malignancy and improves outcome
How is epidural abscess treated
Surgically decompressed and antibiotics given
Treatment of myelopathy when cord herniation or prolapse is present
- EPIDURAL steroid injection for leg pain
- LAMINECTOMY (removal of lamina tissue between discs to relief pressure and symptoms
- MICRODISECTOMY (removal of herniated tissue from disc
What is the Cauda Equine syndrome
- Where nerve bundles in caudal equine are damaged
Most common cause of Cauda Equina syndrome
Lumbar disc herniation at L4/5 or L5/S1
ALSO: Tumours Trauma Infection Spondylolisthesis Post-op haematoma
Pathophysiology of cauda equina syndrome
- Nerve root compression distal to termination of spinal cord at L1/2
Usually large central disc herniations at L4/5 and L5/S1 levels
What roots are compressed in cauda equina syndrome
S1-S5
Clinical Presentation of Cauda Equina syndrome
- Leg Weakness is FLACCID and AREFLEXIC (LMN) not spastic and hyperreflexic
- Sciatic pain, numbness and tingling from lower back to legs and lateral small toe
- Bilateral sciatica
- Saddle anaesthesia
- Bladder/BOwel dysfunction
- Erectile dysfunction
- Variable leg weakness that is FLACCID + AREFLEXIC
Differential Diagnosis of Cauda Equina Syndrome
- Conus medullar is syndrome
- Vertebral fracture
- Peripheral neuropathy
- Mechanical back pain
Diagnostics of Cauda Equina syndrome
- MRI (to find lesion)
- Knee flexion (L5-S1)
- Ankle planter flexion test (S1-S2)
- Straight leg raising (L5,S1)
- Femoral stretch test (L4 root problem)
Treatment of Cauda Equina Syndrome
- REFER to neurosurgeon ASAP to relieve pressure or risk irreversible paralysis
- Microdiscectomy (removal of part of the disc)
- Epidural steroid injection
- Surgical spine fixation
- Spinal fusion
Complications of microdiscectomy
Tears dura
Why is surgical spine fixation done
If vertebra slips
Role of spinal fusion
Reduce pain from motion and nerve root inflammation
Define MS
Chronic autoimmune, T-cell mediated inflammatory disorder of CNS in which there are multiple plaques of demyelination within the brian and spinal cord, occurring sporadically over years
What cells are attacked in MS
Oligodendrocytes NOT Schwann Cells of PNS
What gender is effected by MS
FEMALES
Age presentation of MS
20-40
Risk factors for MS
- Exposure to EBV in childhood
- Low levels of sunlight or Vit D (less lesions are seen on MRi in established MS)
- Female
- WHite
Pathophysiology of MS
- Autoimmune mediated demyelination at multiple CNS sites to oligodendrocyte cells
- T cell activate B cells to produce auto-antibodies against myelin
- T cells cross BBB causing a cascade of destruction to neuronal cells in the brain
- Myelin tries to regenerate but new myelin is less efficient and is temperature dependant when exposed to high heat conduction decreases
- Repeated demyelination causes axonal loss and incomplete recovery between attacks
Where are plaques of demyelination found
perivenular Optic nerves Ventricles of brian Corpus callous Brainstem and cerebellar connections Cervical cord (corticospinal tract and dorsal columns)
Why are Schwann cells unaffected in MS
Different antigens to oligodendrocytes
What causes relapse + remitting MS
Poor demyelination healing after an attack
Why is movement and sensation impaired in MS
Many areas of the neurone develop scar tissue which slows conduction signals
What is relapse and remitting MS
Periods of good health and remission followed by sudden symptoms
Accumulate disability over time if they do not fully recover after relapses
What follows on from relapsing and remitting MS
Secondary progressive MS
What is secondary progressive mS
Worsening of symptoms with very few remissions
What is primary progressive MS
Gradually worsening disability without relapses or remissions
Presents later and fewer inflammatory changes on MRi
Clinical presentation of MS
- 20-40
- Initially mono symptomatic
- Worsens with heat/excercise
- Unilateral optic neuritis (pain in one eye on movement and reduced central vision)
- Numbness and tingling of limbs
- Leg weakness
- Brainstem demyelination symptoms
- Cerebellar symptoms (ataxia)
- Trigeminal neuralgia
- Constipation
- Spasticity and weakness
- Intention tremors
- Bladder dysfunction
- Sexual dysfunction
- Cognitive decline
- Amnesia
Signs of brainstem demyelination
- Diplopia
- Vertigo
- Facial numbness
- Dysarthria/ dysphagia
- Loss of proprioception
Differential diagnosis of MS
- Hereditary spastic paraplegia
- Cerebral variant of SLE
- Sarcoidosis
- HIV
How is MS diagnosed
- Requires TWO or more attacks in different parts of the CMS (2 lesions at different points in time)
- Exclude differentials with FBC
- MRI scan of brian and spinal cord - GOLD
- Lumbar puncture
- Electrophysiology
Role of MRI scan in MS
- Shows periventricular lesions
- Discrete white matter abnormalities
- Scattered plaques
Role of lumbar puncture in MS
- CSF examination shows oligoclonal IgG bands
2. CSF cell count raised
Role of Electrophysiology
Delayed nerve conduction suggests demyelination
Primary treatment of MS
1, Encourage stress-free life (reduces lesions)
2. Poor diet and sun exposure = vit D
Treatment of ACUTE relapses of mS
- IV METHYLPREDNISOLONE (shorten relapse)
- —–FREQUENT relapses)
2. SC INTERFERON 1B or 1A to reduce relapses by 30% in Relapse + remitting MS
3. Monoclonal antibodies
What monoclonal antibodies are given in frequent relapsing and remitting MS
- IV ALETUZUMAB
- IV NATALIZUMAB
- DIMETHYL FUMARATE
Role of iV ALETUZUMAB
CD52 monoclonal antibody that targets T cells
Role of IV NATALIZUMAB
Acts against VLA-4 receptors that allow immune cells to cross the BBB (reduces number of immune cells that can enter the CNS)
Symptomatic treatment of MS spasticity
- Physiotherapy
- BACLOFEN
- TIZANIDINE
- BOTOX INJECTIONS
- DOXAZOSIN (for incontinence)
- Stem cell transplant
What is Baclofen
GABA analogue that reduces Ca@+ influx
What is Tizanidine
Alpha 2 agonist
What is Botox injection
Reduces ACh in neuromuscular junction = less spasticity
Cons of botox
Only lasts 2-12 weeks
How is urinary incontinence treated in MS
- Intermittent self-catheterisation
2. DOXASOSIN (anti-cholinergic alpha blocker
What causes death in MS
Aspiration pneumonia
Define myasthenia Gravis
Autoimmune disease against AChR in neuromuscular junction
What gender is affected in Myasthenia Gravis
FEMALES than males
Peak incidence of MG in females
30
Peak incidence of MG in males
60
What diseases are associated with MG for females
pernicious anaemia
SLE
Rheumatoid arthritis
THYMIC HYPERPLASIA
What disease is associated with MG in men
THYMIC ATROPHY
THYMIC CTUMOUR
rheumatoid arthritis
SLE
What causes transient MG
D-PENICILLAMINE treatment
Wilson’s disease