Week 4 Flashcards
When do patients with MS typically present first?
30s and 40s
What demyelinating disorder is optic neuritis associated with?
MS
Give three features of pyramidal dysfunction in patients with MS?
- Increased tone
- Spasticity
- Weakness
Name some sensory symptoms in MS?
- Pain
- Paraesthesia
- Dorsal column loss - proprioception and vibration
- Numbness
- Trigeminal neuralgia
What dysfunction is present with ataxia, intention tremor, nystagmus, past pointing, pendular reflexes, dysdiadokinesis and dysarthria?
Cerebellar dysfunction
Give two features of brainstem dysfunction in MS?
- Diplopia
2. Facial weakness
Medial longitudinal fasciculus Distortion of binocular vision Failure of adduction- diplopia Nystagmus in abducting eye Lag
Internuclear ophthalmoplegia - MS
What is used to treat fatigue in MS?
Amantadine
Modafinil if sleepy
Hyperbaric oxygen
Give three investigations for possible MS?
- MRI
- CSF
- Neurophysiology
How is a mild acute exacerbation of MS treated?
Symtpomatic treatment
How is a moderate acute exacerbation of MS treated?
Oral steroids
How is a severe acute exacerbation of MS treated?
Admit and IV steroids
Give four ways to treat spasticity in MS?
- pHYSIOTHERAPY
- Oral baclofen and tizanidine
- Botulinum toxin
- Intrathecal baclofen/phenol
Give two drugs for treating sensory symptoms in MS?
- Gabapentin
2. Amitriptyline
Give four ways to treat lower urinary tract dysfunction in MS?
- Bladder drill
- Anti cholinergics oxybutynin
- Desmopressin
- Catheterisation
List three first line disease modifying therapies for MS?
- Interferon Beta - avonex, rebif
- Glitiramer Acetate (copaxone)
- Tecfedira
List two second line therapies for MS?`
- Monoclonal antibody
2. Fingolimod
Name a third line therapy for MS?
Mitoxantrone
What drug is first line, oral agent in relapsing remitting MS?
Tecfidera
List the three cells involved in direct pathway for signal transmission in the retina?
Photoreceptors
Bipolar cells
Ganglion cells
What cells in teh retina receive input from photoreceptors and project to other photoreceptors and biopolar cells?
Horizontal cells
What cells in the retina receive input from bipolar cells and project to ganglion cells, biopolar cells and other amacrine cells?
Amacrine cells
What is the role of photoreceptors?
Transduction
In relation to the dark current - when is the cGMP sodium channel open/
In the dark and closes in the light
What is rhodopsin (for rods) made from?
Retinal vitamin A derivative + opsin (GPCR)
What does light convert 11-cis-retinal to?
All-trans-retinal (activated form)
What activates transfucin leading to molecular cascade that decreases cGMP, leading to closure of sodium channels and hyperpolarisatio?
All-trans-retinal
Is there more glutamate in the dark or light?
In the dark
What photoreceptors are for dim light?
Rods - more convergence
Where in the retina are rods found?
Peripheral retina
Where in the retina are ocnes fround?
Central retina - fovea
Do rods have higher visual acuity than cones?
No they have low visual acuity
Are bipolar cells (OFF pathway) more positive in light or dark?
Dark - more glutamate
Are bipolar cells (ON pathway) more positive in light or dark?
Light
What cells in signal transmission (vision) produce APs?
Ganglion cells
In relation to vision what does lateral inhibition imporve?
Stimulus localisation
What modifies the receptive fields of ganglion cells to have a center-surround organisation?
Lateral inhibition
What does center-surround organisation/lateral inhibtion serve to do?
Emphasise areas of difference (contrast) i.e,. sharpens boundary between objecys of different luminance
Nerve fibres from what half of each retina cross over at optic chiasm?
Nasal half
What are motor end plates?
The synapses formed between motor neurons and muscle are called the motor end plate
Who is lkely to be affected by the presynaptic disorder botulism?
IV drug users - black tar heroin
What symptoms does botulism give?
Rapid onset weakness without sensory loss
What involves antibodies to presynaptic calcium channels leading to less vesicle release. Strong association with underlying small cell carcinoma?
Lambert Eaten Myasthenic Syndrome
Name a post synaptic disorder?
Myasthenia Gravis
What is the most common disorder of neuromuscular junction?
Myasthenia grais
What condition is related to antibodies to acetyl choline receptors (AChR)?
Myasthenia gravis
In Myasthenia Gravis what happens to the number of ACh receptors and endplate folds?
Reduced number and flattening of endplate folds
What do 75% of myasthenia gravis patients also have?
Hyperplasia of thymus or thymoma
What are some clnical features of myasthenia gravis?
Weakness fluctuating - worse through day
Extraocular weakness, facial and bulbar weakness
limb weakness typically proximal
How do you treat myasthenia gravis?
Acetylcholinesterase inhibitor - pyridostigmine
Thymectomy
What is the actin myosin ratio in smooth muscle?
10 : 1
What is a fasciculation?
Visible, fast, fine spontaneous twitch
What precipitates fasciculations?
Stress, caffeine and fatigue
What is usually a sign of disease in the motor neurone, not the muscle?
Fasciculations
What is myotonia?
Failure of muscle relaxation after use - chloride channel
What infalmmatory condition is symmetrical, progressive proximal weakness, raised CK and responds to steroids?
Polymyositis
Heliotrope rash on face and up to 50% have underlying malignancy>?
Dermatomyositis
Give a degenerative muscle disease?
Inclusion body myositis
Slowly progressive weakness in 6th decade of life with characteristic thumb sparing?
Inclusion body myositis
What is the commonest muscular dystrophy?
Myotonic dystrophy
What heritance is myotonic dystrophy?
Autosomal dominant
Myotonia, weakness, cataracts, ptosis, frontal balding, cardiac defects
Trinucleotide repeat disorder with anticipation
Myotonic dystrihyt
Myalgia, muscle weakness and myoglobinuria?
Rhabdomyolysis
Gie two complications of rhabdomyolysis?
Acute renal failure
DIC
What are the two peaks of incidence for myasthenia gravis?
Females in 3rd decade
Males in 6th/7th decade
Name an untreatable and rapidly progressing neurodegenerative condition?
Motor neuron disease
Name some symptoms of MND?
Muscle weakness
speech, swallo and breathing
What condition shows upper and/or lower motor neurone signs without sensory problems
MND
What does MND lead to?
Focal onset, continuous spread and finally generalised paresis
How long is average MND survival time?
3 years
90% sporadic, 10% familial?
MND
wHAT IS THE 70% site of onset for MND?
Extremities
What motor neuron is more affected in MND?
Lower motor neurone 90%
Is the bulbar variant of MND more common in women or men?
Women (60-80 years)
How is MND diagnosed?
Diagnosis of exclusion
What kind of ementia is asociated with MND?
Fronto temporal
Are these signs upper or lower motor neuron - spasticity, babinski sign?
UMN
Name some bulbar UMN signs?
- Exaggerated snout reflex
- Clonic jaw jerk
- Emotional lability
- Forced yawning
Name some cervical and lumbar region UMN sings?
- Clonic deep tendon reflexes
- Wasted limb
- Hoffman reflex
- Hyperreflexia
Upper or lower MN dysfunction - severe weakness, fasciculations, muscle cramps, muscle hypotonicity, muscle atrophy, hyporeflexia?
Lower
upper or lower MN dysfunction - pseudobulbar affect, moderate weakness, spasticity, hyperreflexia, extensor plantar reflexes?
Upper