Neuro 2 Flashcards
what is bulbar palsy?
bulbar palsy denotes diseases of the nuclei of CN IX-XII in the medulla
what are the signs of bulbar palsy?
LMN lesion of the tongue and muscles of talking and swallowing: flaccid, fasciulating tongue (like a sac of worms); jaw jerk Is normal or absent, speech is quiet, hoarse or nasal
what are the causes of bulbar palsy?
MND GBS polio MG brainstem tumours syringobulbia
what is corticobulbar palsy ?
UMN lesion of muscles of swallowing and talking due to bilateral lesions above the min-pons eg corticobulbar tracts (MS, MND, stroke, central pontine myelinolysis)
it is commoner than bulbar palsy
what are the signs of corticobulbar palsy?
slow tongue movements, with slow deliberate speech, increased jaw jerk, increased pharyngeal and palatal reflexes. pseudobulbar affect (weeping unprovoked by sorrow or mood-incongruent giggling - extremely laughing or crying)
what is pseudobulbar affect seen in?
parkinsons brain tumour brain injury stroke dementia
what is ataxia?
ataxia is the name given to a group of neurological disorder that affect balance, coordination and speech
what is the cause of cerebellar syndrome?
Friedreich’s ataxia - AR, typical onset 10-15 years, gait ataxia and kyphoscoliosis are most common
Ataxic telangiectasia - AR, cerebellar ataxia, telangiectasia are common features
neoplasm - cerebellar haemangioma
stroke, alcohol, MS, hypothyroidism
drugs - phenytoin and lead posing
how does cerebellar syndrome present?
DANISH
- D - dysdiadochokinesia, Dysmetria (past pointing, Drunk (may appear drunk)
- ataxia - limb and truncal
- nystagmus - intention tremor
- slurred staccato speech, scanning dysarthria
- hypotonia
what is paraplegia?
paralysis of both legs - always cause by spinal caused by spinal cord lesion
what is hemiplegia?
paralysis of one side of the body caused by a lesion in the brain
what are the different tracts in the spinal cord?
corticospinal (motor, descending UMN, decussates at the medulla)
dorsal column (ascending sensory tract, proprioception, vibration and 2 point discrimination, decussates at the medulla)
spinothalamic (ascending sensory tract), pain and temp, decussates almost immediately in the spinal cord)
what are UMN signs?
Upper motor neurone signs: signs are CONTRALATERAL to lesion
• Indicate that the lesion is above the anterior horn cell i.e. in the spinal
cord, brainstem and motor cortex
• Increased muscle tone - SPASTICITY:
- Velocity dependent and non-uniform i.e. the faster you move the
patients muscle, the greater the resistance, until it finally gives way
in a clasp-knife manner
• Weakness:
- Flexors are generally weaker than extensors in legs and reverse in
arms
• Increased reflexes, they are brisk - HYPERREFLEXIA
what are lower motor neurone signs?
Lower motor neurone signs: signs are IPSILATERAL to lesion
• Indicate that the lesion is either in the anterior horn cell or distal to the
anterior horn cell i.e. in anterior horn cell, plexus or peripheral nerve
• Decreased muscle tone
• WASTING (atrophy) +/- FASCICULATIONS (spontaneous involuntary
twitching)
• Weakness that corresponds to those muscles supplied by the involved
cord segment, nerve root, part of plexus or peripheral nerve
• Reflexes are reduced or absent
what is spondylolisthesis?
Slippage of one vertebra over the one below
Nerve root comes out ABOVE the disc, therefore root affected will be the
one BELOW the disc herniation e.g. L4/L5 herniation leads to L5 nerve
root compression
what is myelopathy?
caused by spinal cord compression - UMN signs
spasticity, weakness, hyperreflexia
spinal cord disease
what is radiculopathy?
caused by spinal root compression = LMN signs decreased muscle tone wasting weakness fasciculations pain down dermatome weakness in myotome no UMN signs
what are some causes/risk factors for spinal cord compression?
vertebral body neoplasms (most common cause of acute compression usually secondary malignancy) spinal pathology (disc herniation, disc prolapse, spinal stenosis - can occur in the central canal producing myelopathy)
rarely may be caused by infection, haematoma (warfarin), primary spinal cord tumour (glioma, neurofibroma)
what is the clinical presentation of spinal cord compression?
back pain - the earliest and most common symptom - may be worse on lying down and coughing
lower limb weakness
sensory changes: sensory loss and numbness
neurological signs depend on the level of the lesion. Lesions above L1 usually result in upper motor neuron signs in the legs and a sensory level. Lesions below L1 usually cause lower motor neuron signs in the legs and perianal numbness. Tendon reflexes tend to be increased below the level of the lesion and absent at the level of the lesion
in acute compression - often tone and reflexes take time to develop
how do you diagnose spinal cord compression?
do not delay imaging at any cost - irreversible paraplegia may follow if the cord is not decompensated
MRI is the cold standard - it identifies the cause and sit of compression
screening bloods
CXR
how do you treat spinal cord compression
immobilisation and decompressive/stabilisation surgery
high-dose oral dexamethasone
urgent oncological assessment for consideration of radiotherapy or surgery
what is cauda equine syndrome?
it is a medical emergency
- the cauda equina is formed by the nerve roots distal to the level of termination of the spinal cord at L1/L2
cauda equina syndrome is damage at or caudal to L1
what are the functions of the frontal lobe?
voluntary movement on opposite side of body
frontal lobe of dominant hemisphere controls speech (broca’s area) and writing.
intellectual functioning, thought processes, reasoning and memory.
what is the function of the parietal lobe?
Receives and interprets sensations, including pain, touch, pressure, size and
shape and body-part awareness (proprioception)
what is the function of the temporal lobe?
Understanding the spoken word (Wernicke’s - understanding), sounds as well
as memory and emotion
what is the function of the occipital lobe?
Understanding visual images and meaning of written words
how many spinal nerves are there?
31 pairs
- Cervical - 8 nerves
- Thoracic - 12 nerves
- Lumbar - 5 nerves
- Sacral - 5 nerves
- Coccyx - 1 nerve
how should you treat a myasthenic crisis?
plasmapheresis and IV IG
what is spinal stenosis?
it is a condition typically resulting from degenerative changes in the lumbar spine
it leads to a narrowed spinal canal, lateral recesses and neural foramina
it is a common causes of spinal compression
what are the symptoms of spinal stenosis?
- back pain
- activity related back pain
- leg pain when walking
- stooped posture when walking
- leg numbness or paraesthesia
- absence of examination findings - (neurological deficits are common, diminished ankle/knee jerk reflex might be present)
what are some causes of spinal stenosis?
facet joint and ligamentous hypertrophy
intervertebral disc protrusion
spondylolisthesis
what investigations should you perform for spinal stenosis?
plain XR - degenerative changes or spondylolisthesis
MRI - compression of the neural elements and soft tissue
how would you treat spinal stenosis?
if there is significant acute neurological deficit - surgical decompression
if there isn’t then give analgesics
what are the complications of spinal cord compression?
cauda equina
permanent neurological deficit
complication from immobility
progression of spondylolisthesis after surgery.
what are some common causes of a foot drop?
- L5 radiculopathy
- sciatic nerve lesion
- common peroneal nerve lesion
- superficial or deep peroneal nerve lesion
- other possible includes central nerve lesions (e.g. stroke) but other features are usually present
what is sciatica?
pain, numbness and a singling sensation that radiates from the lower back and travels down one of the legs to the foot and toes
S1 nerve root compression
how would cauda equine syndrome present?
flaccid, areflexic weakness bilateral sciatica saddle anaesthesia bladder/bowel dysfunction erectile dysfunction variable leg weakness
what are some differential diagnosis for cauda equina syndrome?
conus medullaris syndrome
vertebral fracture
peripheral neuropathy
mechanical back pain
what investigations would you perform for cauda equina syndrome?
MRI to localise lesion
knee flexion - test L5-S1
ankle plantar flexion (downwards) - test S1-S2
straight leg raising L5, S1, too problem - people with acute disc can barely get one leg off bed
femoral stretch test - L4 root problem
how would you treat cauda equina syndrome?
refer to neurosurgeon ASAP to relieve pressure or risk of irreversible paralysis/sensory loss/incontinence
Microdiscectomy - removal of part of the disc - may tear dura!
• Epidural steroid injection - more effective for leg pain
• Surgical spine fixation - if vertebra slipped
• Spinal fusion - reduces pain from motion and nerve root inflammation
what is peripheral neuropathy?
damage to the peripheral nerves - can be divided into conditions which predominantly cause a motor loss or sensory loss
what are some peripheral neuropathies that cause predominantly motor loss?
Guillain-Barre syndrome - demyelinating neuropathy
Diphtheria - infective neuropathy
lead poisoning - toxic neuropathy
Charcot-Marie-Tooth (hereditary sensorimotor neuropathy) - degenerative neuropathy.
what peripheral neuropathies cause predominantly sensory loss?
- diabetes (metabolic/infarctive neuropathy)
alcoholism - toxic neuropathy - secondary to both direct toxic effects and reduced vitamin absorption - sensory symptoms typically present prior to motor symptoms.
vitamin b12 deficiency
leprosy
amyloidosis
how may a sensory neuropathy present?
numbness - pins and needles
affects extremities first e.g. glove and stocking distribution
there may be difficulty handling small objects such a buttons
signs of trauma e.g. finger burns or joint deformation may indicate sensory loss
diabetic and alcoholic neuropathies are typically painful
how may peripheral motor neuropathy present?
- often progressive - - may be rapid
- weak or clumsy hands
- difficulty in walking e.g. falls and stumbling
- difficulty breathing e.g. reduced vital capacity
- LMN lesion: wasting and weakness is most marked in the distal muscle of the hands and feet - foot or wrist drop, reflexes are reduced are absent
what is alcoholic neuropathy?
secondary to both direct toxic effects and reduced absorption of B vitamins
sensory symptoms typically present prior to motor symptoms
