Flashcards in Week 4 Deck (81):
When do patients with MS typically present first?
30s and 40s
What demyelinating disorder is optic neuritis associated with?
Give three features of pyramidal dysfunction in patients with MS?
1. Increased tone
Name some sensory symptoms in MS?
3. Dorsal column loss - proprioception and vibration
5. Trigeminal neuralgia
What dysfunction is present with ataxia, intention tremor, nystagmus, past pointing, pendular reflexes, dysdiadokinesis and dysarthria?
Give two features of brainstem dysfunction in MS?
2. Facial weakness
Medial longitudinal fasciculus
Distortion of binocular vision
Failure of adduction- diplopia
Nystagmus in abducting eye
Internuclear ophthalmoplegia - MS
What is used to treat fatigue in MS?
Modafinil if sleepy
Give three investigations for possible MS?
How is a mild acute exacerbation of MS treated?
How is a moderate acute exacerbation of MS treated?
How is a severe acute exacerbation of MS treated?
Admit and IV steroids
Give four ways to treat spasticity in MS?
2. Oral baclofen and tizanidine
3. Botulinum toxin
4. Intrathecal baclofen/phenol
Give two drugs for treating sensory symptoms in MS?
Give four ways to treat lower urinary tract dysfunction in MS?
1. Bladder drill
2. Anti cholinergics oxybutynin
List three first line disease modifying therapies for MS?
1. Interferon Beta - avonex, rebif
2. Glitiramer Acetate (copaxone)
List two second line therapies for MS?`
1. Monoclonal antibody
Name a third line therapy for MS?
What drug is first line, oral agent in relapsing remitting MS?
List the three cells involved in direct pathway for signal transmission in the retina?
What cells in teh retina receive input from photoreceptors and project to other photoreceptors and biopolar cells?
What cells in the retina receive input from bipolar cells and project to ganglion cells, biopolar cells and other amacrine cells?
What is the role of photoreceptors?
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?
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?
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?
What cells in signal transmission (vision) produce APs?
In relation to vision what does lateral inhibition imporve?
What modifies the receptive fields of ganglion cells to have a center-surround organisation?
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?
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?
What is the most common disorder of neuromuscular junction?
What condition is related to antibodies to acetyl choline receptors (AChR)?
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
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?
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?
Heliotrope rash on face and up to 50% have underlying malignancy>?
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?
What heritance is myotonic dystrophy?
Myotonia, weakness, cataracts, ptosis, frontal balding, cardiac defects
Trinucleotide repeat disorder with anticipation
Myalgia, muscle weakness and myoglobinuria?
Gie two complications of rhabdomyolysis?
Acute renal failure
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?
speech, swallo and breathing
What condition shows upper and/or lower motor neurone signs without sensory problems
What does MND lead to?
Focal onset, continuous spread and finally generalised paresis
How long is average MND survival time?
90% sporadic, 10% familial?
wHAT IS THE 70% site of onset for MND?
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?
Are these signs upper or lower motor neuron - spasticity, babinski sign?
Name some bulbar UMN signs?
1. Exaggerated snout reflex
2. Clonic jaw jerk
3. Emotional lability
4. Forced yawning
Name some cervical and lumbar region UMN sings?
1. Clonic deep tendon reflexes
2. Wasted limb
3. Hoffman reflex
Upper or lower MN dysfunction - severe weakness, fasciculations, muscle cramps, muscle hypotonicity, muscle atrophy, hyporeflexia?