Neuro Peer Teaching Flashcards
Define ‘neurodegeneration’.
The progressive loss of function of neurones due to cell death or degeneration.
eg. abnormal depositions / gross anatomical change.
Give a definition of ‘dementia’.
Latin - ‘loss of mind’
- Decline in memory, intellect or personality which is severe enough to interfere with ADL.
How is dementia diagnosed?
- Predominantly a clinical diagnosis
What should be included in a ‘routine dementia screen’?
- Bloods
- Urinalysis
- Psychometric testing
- MRI brain
What is the most common cause of dementia in the developed world?
Alzheimer’s Disease
Describe the prognosis for a patient diagnosed with Alzheimer’s disease.
- Incurable disease
- Long, progressive course
Give 3 pathophysiological hallmarks seen in Alzheimer’s Disease.
- B-amyloid plaques
Accumulation of amyloid in the hippocampus, enterhinal cortex and amygdala. - Neurofibrillary tangles
Intracellular accumulation of Tau (a protein) - Cortical atrophy
Most pronounced in frontal and temporal lobes
A person is diagnosed with Alzheimer’s disease. What would be seen on functional imaging tests?
- Reduced blood flow + Reduced glucose metabolism in temperoparietal regions + hippocampus.
- Cortical atrophy
- Enlarged ventricles
Describe the clinical picture of someone with Alzheimer’s Disease.
- Episodic memory
- Visuospatial problems
- Getting lost in familiar places
4 As:
- Aphasia
- Anomia
- Acalculia
- ADLs -> struggling to cope
Describe the clinical picture of someone with the late stages of Alzheimer’s disease.
- Frank dementia
- Bradykinesia
- Psychosis
- Seizures
- Incontinence
- Mutism
Describe the investigation pathway if you suspect a patient has Alzheimer’s disease.
- Rule out other causes
- Neuropsychological testing: Addenbrookes (differentiates between fronto-temporal dementia and Alzheimer’s disease
MMSE
MOCA - Imaging
What treatment might be used for a person with Alzheimer’s Disease?
No curative treatment :(
- AChE inhibitors eg. Donepezil, Rivastigmine, Galantamine
- these inhibit ACh degradation at the synaptic cleft
- NMDA antagonists - behavioural
- Antidepressants / psychotics
Describe the non-pharmacological management of a person with Alzheimer’s Disease.
- Cognitive training
- Emotional and social stimulation eg. art therapy
- Exercise programmes
- Caregiver training programmes
What are the 5 things to remember with regards to Dementia with Lewy Bodies?
- Visual hallucination
- Fluctuation
- Parkinsonism
- sleep disorders
- Psychosis
What is the Parkinsonism triad?
- Bradykinesia
- Tremor
- Rigidity
On investigation of a patient for dementia with lewy bodies, what would psychometric testing reveal?
- Deficits in attention
- Executive function decline
- Fluctuation of cognitive performance
- Episodic memory preserved
What are the pathological features of Dementia with Lewy Bodies?
- Pallor of substantia nigra
- Lewy bodies (alpha-synuclein)
How should Dementia with Lewy Bodies be treated?
Difficult to treat :(
- Anti-Parkinsons Tx can worsen psychosis
- Avoid neuroleptics
Why should neuroleptics be avoided in the treatment of Dementia with Lewy Bodies?
Causes tardive dyskinesia
-> hypersensitivity to dopamine in the nigrostriatal pathway
Which type of dementia is the 3rd most common?
Vascular dementia
List some risk factors for developing Vascular dementia.
- Smoking
- Overweight / obese
- Sedentary lifestyle
- Poor diet
What are the 2 main types of vascular dementia, and how do these differ?
- Step-wise decline: mini-strokes; multi-infarct
2. Generalised decline: diffuse white matter disease
List 4 distinguishing features of Vascular Dementia.
Some cross-over with Alzheimer’s
- Good and bad days
- ‘Sundowning’
- Mood plays a bigger role
- Emotional incontinence
- Inappropriate laughter or tearfulness
- Focal neurology
Describe the differences between small vs large vessel disease in Vascular Dementia.
Small:
- white matter disease (hypertension)
- lipohyalinosis
Large:
- Strategic infarct
How might Vascular Dementia be managed?
- Non-pharmacological interventions
- AChE and NMDA inhibitors are NOT recommended
- Manage emotional symptoms
- MODIFIABLE AND PREVENTABLE!!! -> lifestyle!
Give a definition for ‘Fronto-temporal dementia’.
- A group of conditions
- Selective degeneration of frontal and temporal lobes
Which other condition is fronto-temporal dementia linked to?
Motor Neurone Disease
Who does Fronto-temporal dementia tend to affect?
Younger people
Which protein has a role in fronto-temporal dementia?
Tau
-> there is a genetic component to FT dementia + it is related to a TDP-43-opathy.
What are the 3 main clinical pictures of fronto-temporal dementia?
- Behavioural variant
- Semantic
- Progressive non-fluent aphasia.
A patient has the ‘behavioural variant’ or fronto-temporal dementia. How might they be acting?
- Apathetic
- Disinhibition
- Lack of insight
- Emotional lability
A patient has the ‘semantic’ version of fronto-temporal dementia. How might they be acting?
- Can speak
- Receptive aphasia
A patient has the ‘progressive non-fluent aphasia’ version of fronto-temporal dementia. Describe their speech.
- Expressive aphasia.
What investigations should you carry out for suspected Fronto-temporal dementia?
MRI -> ?fronto-temporal atrophy
Genetic testing
Assess for Motor Neurone Disease
What treatment can you offer a person recently diagnosed with fronto-temporal dementia?
- SSRIs
- Holistic management
Where are motor neurones most commonly affected in Motor Neurone Disease?
Anterior Horn
Describe the pathophysiology of motor neurone disease.
- Causes preferential progressive loss of motor neurones and ultimate dismantling of the motor neurone system.
What are the mechanisms by which motor neurone disease wreaks havoc?!
- Excitotoxicity due to over activation of glutamate receptors
- Oxidative stress -> free radical formation
- Protein misfolding
- Microglial activation
- Mitochondrial dysfunction
Describe the clinical picture of a patient with MND.
- Dysfunction / weakness in one part of body -> spreads gradually
- Weight loss
- Resp failure -> failure of muscles of ventilation.
What are the sensory signs + symptoms seen in MND?
There are none.
List the Upper Motor Neurone signs seen in MND.
- Hypertonia
- Hyperreflexia
- Up-going plantars
- Weakness
List the Lower Motor Neurone signs seen in MND.
- Weakness
- Wasting
- Reduced tone
- Reduced reflexes
- Fasciculations
What are the lumbar signs seen in MND?
- Foot drop
- Fasciculations (especially in the thigh)
What are the bulbar signs seen in MND?
- Jaw jerk
- Dysarthria
- Swallowing
What is the prognosis for a patient with MND?
- Incurable: death in average 3 years
- Weight loss = poor prognosis (due to hyper metabolic state)
What considerations should you make when treating a person with MND?
- Nutritional management
- Non-invasive ventilation
- Counselling
What is the Parkinson’s triad?
- Bradykinesia
- Rigidity
- Resting tremor
- plus non-motor symptoms
What are the 2 main neurological findings in a person with Parkinson’s disease?
- Loss of dopaminergic neurones in the substantial nigra pars compacta
- Presence of Lewy Bodies
Describe the pathophysiology of Parkinson’s disease.
- Decreased production of dopamine -> decreased striatal dopamine stimulation = decreased inhibition of GPi/SNr
-> Increased GPi/SNr activity => increased inhibitory output to thalamic nuclei (which project to primary motor areas)
=> suppressed movement
List some non-motor signs seen in a Parkinson’s patient.
- Hyposmia
- Excessive saliva production / drooling
- Memory impairment
- Autonomic dysfunction
- Depression / anhedonia
- REM sleep disorders
- non-motor symptoms often precede motor signs.
Parkinson’s Disease is a largely clinical diagnosis. What questions should you ask about in the patient’s history?
- Unilateral onset
- Resting tremor
- Anosmia
- Progressive
- Excellent response to L-Dopa
- L-Dopa response for 5+ years
- 10+ years clinical course
- Visual hallucinations
What medications might be used for a Parkinson’s patient?
- Levodopa (dopamine precursor)
- Carbidopa (peripheral decarboxylase inhibitor)
What clinical features might ‘Parkinson’s Plus’ exhibit?
- Falls at presentation -> ? Multiple System Atrophy
- Poor response to L-Dopa
- Rapid progression of disease
- Absence of tremor
- Symmetry at onset
- Eye involvement (? progressive supra nuclear palsy)
Give 2 features of Multiple System Atrophy (a Parkinson’s plus syndrome).
- Symmetrical in onset
- Parkinsonism with autonomic, corticospinal and cerebellar dysfunction
List 6 features of Dementia with Lewy Bodies / Parkinson’s Disease Dementia.
DLB: Progressive, degenerative dementia. Cognitive impairment precedes motor signs
- Visual hallucinations
- Fluctuating cognitive function
- Excessive daytime somnolence
- Anterograde memory loss
- Delusions
List 4 features of the Parkinson’s Plus condition ‘Progressive Supranuclear Palsy’.
- Tauopathy tau
- Symmetrical
- Parkinsonism
- Early falls
List 5 features of the Parkinson’s Plus condition ‘Supranuclear Gaze Palsy’.
- Pt has difficulty with voluntary down gaze
- Surprised look
- Poor response to Dopamine
- ?PEG feeding due to pseudo bulbar palsy
- 5 years to incapacity :(
List some acute causes of headache.
- Infection: meningitis / encephalitis
- Haemorrhage: SAH, Extradural
- Venous sinus thrombosis
- Sinusitis
- Low pressure headache: CSF leak
- Acute glaucoma
List some chronic causes of headache.
- Tension headache
- Migraine
- Cluster headache
- Trigeminal neuralgia
- Raised ICP
- Medication overuse headache
- Giant cell arteritis
25 yo female presents with a Hx of unilateral, pulsatile headaches that last up to 24 hours, with nausea + photophobia. Diagnosis? Triggers? Treatment? Considerations?
Migraine
Acute: NSAIDs, Triptans
Chronic: beta blockers, amitriptyline, topiramate
If aura, can’t use COCP.
Topiramate = teratogenic.
Describe the presentation and management of a pt with a cluster headache.
- Unilateral pain around the eye
- Watery / bloodshot eye
- Clusters of headaches followed by pain free periods for months or years
Mx: Oxygen, Sumatriptan
Describe the management of a patient with Trigeminal neuralgia.
- All cases need an MRI
- Carbamazepine
- (Lamotrigine, Phenytoin, Gabapentin)
- Microvascular decompression
Describe the investigations + management of a patient with Giant Cell Arteritis.
Ix: ESR, raised CRP, Temporal artery biopsy = negative
Mx:
Steroids -> prednisolone 60mg
PPI -> protect stomach
Bisphosphonates -> protect bone
Give a complication of Giant Cell Arteritis.
Visual Loss.
What are the 2 types of stroke?
- Ischaemic (85%)
- Haemorrhagic (15%)
List some risk factors for stroke.
- HTN
- Smoking
- Diabetes Mellitus
- Heart disease: Valvular, Ischaemic, AF
- Peripheral vascular disease
- Previous TIA
- COCP
- Alcohol use
- Hyperlipidaemia
- Clotting abnormalities
Define ‘TIA’.
Stroke symptoms lasting <24hours
What is the risk stratifying score for TIA?
ABCD2 - Age >60yrs - Blood pressure >140/90 - Clinical features of the event > unilateral weakness > speech disturbance without weakness > other - Duration of symptoms Over 60mins, 10-59 mins, less than 10mins - Diabetes: presence or absence.
How would you manage a TIA conservatively?
- Reduce blood pressure
- Reduce cholesterol
- Control diabetes
- Diet + exercise
- DVLA: can’t drive for 1 month.
How would you medically manage a TIA?
Clopidogrel 75mg
-> aspirin or dipyridamole if not tolerated
How would you surgically manage a TIA?
Carotid endarterectomy if >70% occlusion
Which arteries are affected if a person has a Total Anterior Circulation Infarct or Partial Anterior Circulation Infarct?
Anterior + Middle cerebral artery
What signs + symptoms would a patient with a Total / partial Anterior Circulation infarct present with?
- Unilateral hemiparesis and / or hemisensory loss
- Homonymous hemianopia
- Dysphasia / dysarthria
Which arteries are affected if a person has a posterior circulation infarct?
Vestibulobasilar arteries
How would a posterior circulation infarct present clinically?
- Cerebellar syndromes
- Loss of consciousness
- Homonymous hemianopia
If a patient has a Lacunar infarct, which arteries are affected?
Perforating arteries (supplying internal capsule + basal ganglia)
How would a Lacunar infarct present clinically?
- Pure sensory OR pure motor OR pure sensorimotor
- Ataxic hemiparesis
What is Weber’s syndrome?
Ipsilateral third nerve palsy with contralateral weakness
What is the associated effect if there is a lesion in the Basilar artery?
Locked in syndrome
- paralysed but higher thought functioning is normal
Which artery is affected during Amaurosis fugax?
Retinal artery -> embolism
‘Curtain coming down over vision’
What features should you consider on assessing a patient with a suspected stroke?
- Loss of consciousness / syncope
- Seizure activity
New, acute onset of: - asymmetric facial, arm, leg weakness
- speech disturbance
- visual field defect
Describe the acute management of a stroke (once haemorrhage has been ruled out).
- Stabilise patient
- 300mg Aspirin
- Thrombolysis
What is the criteria for thrombolysis?
Which drug should you use?
- If 4.5 hours from onset of stroke + haemorrhage has been ruled out
- Alteplase
Describe the secondary prevention of a Stroke.
- Modify risk factors: HTN, statin, smoking, weight loss
- Clopidogrel 75mg (aspirin or dipyridamole if not tolerated)
- Carotid endarterectomy
What are the causes of an Extradural haemorrhage?
- Fractured temporal / parietal bone
- > laceration of middle meningeal artery / vein
- Tear in dural venous sinus
How might a patient with an extradural haemorrhage present?
- After head injury
- Lucid interval (hours / days)
- Reduced GCS
- Raised ICP
- Headache
- Vomiting
- Confusion
- Seizures
What investigations should you order if you suspect an extradural haemorrhage?
CT: see an ‘egg shape’ - biconvex
Skull x-ray: ? fracture
What is the management of an extradural haemorrhage?
- Urgent surgery
- Craniotomy / burr hole
What would you see on CT if there was:
i) an acute subdural haemorrhage
ii) a chronic subdural haemorrhage
i) acute = bright blood (looks white)
ii) chronic = dark blood (looks darker!)
What causes a sub-dural haemorrhage?
Bleeding from bridging veins between sinuses - vulnerable to deceleration injuries eg. falls in the elderly
What are the risk factors for sub-dural haemorrhages?
- Elderly
- Falls (epileptics, alcoholics)
- Anticoagulants
How might a patient with a sub-dural haemorrhage present?
- Fluctuating consciousness
- Insidious intellectual slowing
- Personality change
- Sleepiness
- Headache
- Hx of trauma (can be minor)
What are your investigations of choice when investigating a subdural haemorrhage?
What will you see on imaging?
CT / MRI
Crescent shaped collection of blood over 1 hemisphere.
How might you manage a subdural haemorrhage?
- Conservatively
- Craniotomy / burr hole
What is the cause of subarachnoid haemorrhage?
Rupture of saccular / berry aneurysms (80%) or artery-venous malformations
What are the risk factors for SAH?
- Smoking
- Alcohol
- HTN
- Bleeding disorders
Where are the most common sites for berry aneurysms?
- Posterior communicating meets internal carotid
- Anterior communicating meets anterior cerebral
- Bifurcation of middle cerebral artery
What other conditions are Subarachnoid haemorrhages associated with?
- PKD
- Coarctation of the aorta
- Ehlers-Danlos
How might a SAH present?
- Thunderclap occipital headache
- Vomiting
- Collapse
- Neck stiffness
- Kerning’s sign
What pupil changes might you see in conjunction with a SAH?
CN III palsy seen with a posterior communicating aneurysm.
What investigations should you order for a suspected SAH?
- CT head
- LP after 12 hours -> CSF bloody, then xanthochromia (yellow - bilirubin breakdown)
What is the treatment for SAH?
- Resuscitation
- Calcium Channel Blockers (Nimodipine) to reduce vasospasm
- Endovascular intervention (coiling, surgical clipping, angioplasty).
List some causes of seizures.
- Epilepsy
- Febrile convulsions
- Alcohol withdrawal seizures
- Psychogenic non-epileptic seizures
- Brain injury
- Infection
- Trauma
- Metabolic disturbance
Describe a ‘focal’ / ‘partial’ seizure.
Seizure activity is limited to a part of one hemisphere.
‘Focus’ = site in brain where the seizure began.
Describe a ‘complex partial seizure’.
A disturbance of consciousness or awareness.
Describe a ‘generalised seizure’. List the 4 types of generalised seizure.
Generalised seizure: widespread seizure activity in both hemispheres.
- Absence
- Tonic-clonic
- Myoclonic
- Atonic
Describe an ‘Absence’ seizure.
Brief episode where patient appears blank / staring
Describe a tonic-clonic seizure.
Muscle rigidity followed by repeated contraction and relaxation (shaking).
Describe a myoclonic seizure.
Brief, rapid, muscle jerks
Describe an ‘atonic’ seizure.
‘Drop attacks’
Lose muscle tone + drop to the ground.
When is anti-seizure treatment usually started?
- After 2nd seizure OR
- After 1st seizure if neurological deficit, structural abnormality, positive EEG, risk of a further seizure is unacceptable
What is the treatment for Generalised seizures?
Sodium Valproate
2nd line: Lamotrigine, Carbamazepine
What is the treatment for partial / focal seizures?
Carbamazepine
2nd line: Leveritacetam (Keppra)
What is the treatment for absence seizures?
Sodium Valproate or Ethosuximide
* Carbamazepine can worsen absence seizures *
Why should women of childbearing age / pregnant avoid:
i) Sodium Valproate ?
ii) Phenytoin ?
What are their options?
i) Sodium Valproate =.> neural tube defects
ii) Phenytoin => cleft palate
Options:
Lamotrigine
Carbamazepine
What is the pathophysiology of Multiple Sclerosis?
T-cell mediated immune response, causing demyelinated plaques in the CNS.
Describe the visual symptoms which may arise in MS.
- Optic neuritis (unilateral eye pain on movement and loss of central vision)
- Optic atrophy
- Uhthoff’s - worsening of visual symptoms when body temperature is increased eg. hot bath
Describe the sensory symptoms which may arise in MS.
- Numbness
- Tingling
- Trigeminal neuralgia
- Lhermitte’s syndrome: paraesthesia in limbs on neck flexion
Describe the motor symptoms which may arise in MS.
Spastic weakness
Describe the cerebellar signs which may occur in MS.
- Ataxia
- Diplopia
- Intention tremor
List 3 ‘other’ symptoms seen in MS.
- Urinary incontinence
- Sexual dysfunction
- Intellectual deterioration
Who does MS tend to affect?
- Women
- Aged 20 - 40
- In a temperate climate (low vitamin D)
Which criteria is used to diagnose MS?
Which imaging modality is used + what would you see on imaging?
Clinical Diagnosis - McDonald Criteria
MRI: demyelinated plaques
What are the 3 types of MS?
- Relapsing-remitting (85%)
- Primary progressive (10%)
- Secondary progressive
How would you manage a patient with MS?
- Reduce stress
- Vitamin D
- Methyprednisolone for 5 days (shorten acute relapses)
- DMARDs
Give examples of DMARDs used to treat MS. What are the symptoms they primarily aim to treat?
- Beta-interferon: reduces the number of relapses
- Azathioprine
- Glatiramer acetate
Treats: spasticity, bladder dysfunction
What is the pathophysiology of Parkinson’s Disease?
Degeneration of dopaminergic neurons in the substantia nigra
What is the Parkinson’s triad?
- Bradykinesia
- Cogwheel rigidity
- Resting tremor
List some other signs + symptoms exhibited by a patient with Parkinson’s disease.
- Shuffling gait with reduced arm swing
- Difficulty initiating movement
- Mask-like facies
- Micrographia
- Anosmia
- REM sleep behaviour disorder
List some psychological implications of Parkinson’s disease
- Depression
- Dementia
- Psychosis
- Visual hallucinations
What are the histological findings in a patient with Parkinson’s disease?
- Lewy bodies
- Eosinophilic cytoplasmic inclusion consisting of alpha-synuclein
Describe the management of a patient with Parkinson’s disease.
- Delay treatment until onset of disabling symptoms
- Dopamine receptor agonists (Bromocriptine, Ropinirole, Cabergoline)
- Levodopa + dopa-decarboxylase inhibitor
- MAO-B inhibitors: inhibit dopamine breakdown (Selegiline)
- Anti-cholinergics: reduce tremor (Benzhexol, Orphenadrine)
- COMT inhibitors (Tolcapone, Entacapone)
Describe a patient with Progressive Supranuclear Palsy.
- Postural instability
- Vertical gaze palsy
- Trunk rigidity
- Symmetrical onset
- Speech + swallow problems
Describe a patient with multiple system atrophy.
Autonomic:
- impotence / incontinence
- postural hypotension
- cerebellar signs
What kind of rigidity is seen in portico-basal degeneration?
- Akinetic rigidity involving one limb
What is seen in a patient with Vascular Parkinsonism?
Pyramidal signs in diabetic / hypertensive patients.
What pattern of inheritance does Huntington’s Disease display?
Autosomal Dominant
Give 4 features of Huntington’s disease
- Inherited
- Neurodegenerative
- Progressive
- Incurable
Which gene is defective in Huntington’s disease?
Huntingtin Gene on Chromosome 4
What is the pathophysiology of Huntington’s Disease?
Degeneration of cholinergic and GABA neurons in striatum of basal ganglia
-> Loss of GABA-mediated inhibition
Huntington’s disease shows an autosomal dominant pattern of inheritance. What are the chances of a person with Huntington’s having a child with Huntington’s?
50% chance of inheriting the disease
Which features of Huntington’s disease tend to develop first?
- Personality changes (irritability, apathy, depression)
- Lack of coordination, unsteady gait
What are the typical features of Huntington’s?
- Chorea (overshooting, unintentional movements)
- Dystonia / hypotonia
- Intention tremor
- Saccadic eye movements
- Fits
- Intellectual impairment
- Progressive dementia
What investigations should you order if you suspect Huntington’s disease?
Genetic Testing
What is the management of Huntington’s disease?
- No curative treatment
- MDT approach
- Symptom control
What medications can be used to control symptoms in Huntington’s Disease?
Dopamine antagonists eg. Tetrabenazine for chorea
Who would be involved in the MDT for a patient who has Huntington’s Disease?
- Genetic counsellors
- SALT
- Dieticians
- Physio
- OT
- Palliative care specialists
- Psychologists
Patients with Huntington’s disease usually die within 20 years after symptoms develop. What do Huntington’s patient tend to die from?
- Pneumonia
- Heart disease
- Suicide
- Choking
- Malnutrition
Give a description of ‘Motor Neuron Disease’.
Degenerative condition that affects motor neurons:
- Motor cortex (UMN)
- Cranial Nerve Nuclei (UMN / LMN)
- Anterior Horn Cells (LMN)
No sensory involvement or cerebellar signs
Never affects eye movements
Which gene mutation is a rare familial cause for Motor Neuron Disease?
SOD-1 gene mutation
What differentiates MND from MS and polyneuropathy?
- No sensory loss or sphincter disturbance in MND
What differentiates MND from Myasthenia Gravis?
Eye movements are not affected in MND.
What are the 4 Motor Neurone Disease sub types?
- ALS (Amyotrophic Lateral Sclerosis)
- Progressive Bulbar Palsy
- Progressive Muscular Atrophy
- Primary Lateral Sclerosis
Describe the pathophysiology of MND subtype ALS (Amyotrophic Lateral Sclerosis).
Amyotrophic: muscle atrophy due to lost motor neurons in anterior horn cells (LMN)
Lateral: Lateral corticospinal tract (UMN)
Progressive Bulbar Palsy is a MND subtype. Which cranial nerves does it affect?
CN IX - XII
Progressive Muscular Atrophy is a subtype of MND. Does it affect purely LMN or purely UMN?
Pure LMN
Primary Lateral Sclerosis is a subtype of MND. Does it affect purely LMN or purely UMN?
Pure UMN
What is the pathophysiology of ALS (MND subtype)?
Loss of motor neurons in motor cortex and anterior horn cells
What are the LMN signs of ALS (MND subtype)?
- Progressive limb weakness (often upper limb)
- Wasting of thenar / tibialis anterior
- Fasciculations
What are the UMN signs of ALS (MND subtype)?
- Hypertonia
- Brisk reflexes
- Upgoing planters
- Spasticity
Describe a classical presentation of ALS (MND subtype).
- 40+ years
- Stumbling spastic gait
- Foot drop
- Proximal myopathy
- Weak grip
- Weak shoulder abduction
- Aspiration pneumonia
- Relentless progression associated with fronto-temporal pneumonia
Which muscles are affected in bulbar (and pseudo bulbar) palsy subtype of MND?
- Muscles of talking, chewing + swallowing
Describe Bulbar palsy (MND subtype) presentation.
- Flaccid, fasciculating tongue
- Absent jaw jerk (LMN signs)
Describe Pseudobulbar palsy (MND subtype) presentation.
- Tongue paralysed
- No fasciculations
- Increased jaw jerk + pharyngeal reflex (UMN signs)
Apart from MND, what might cause Bulbar palsy?
- Guillain Barre
- Polio
- Myasthenia Gravis
- Syringobulbia
- Brain stem tumours
- Central pontine myelinolysis
Apart from MND, what might cause pseudobulbar palsy?
- MS
- Stroke
- Central pontine myelinolysis
Describe the presentation of a person with Progressive Muscular Atrophy (MND subtype).
- Wasting, often in small muscles of hand
- Distal muscles affected first
- May be unilateral start -> soon bilateral
- Pure LMN
Describe the presentation of a person with Primary Lateral Sclerosis.
- Weakness, spasticity
- Can have pseudo bulbar palsy
- Pure UMN
What investigations should you do if you suspect MND?
- Nerve conduction studies (exclude peripheral neuropathy / myopathy)
- Electromyography - MND has a reduced number of action potentials with increased amplitude
- MRI - exclude cervical cord compression, MS and Myelopathy
Describe the conservative management of MND.
- Feeding and respiratory support -> overnight non-invasive ventilation
- MDT approach -> OT, SALT, Physio, Dieticians, MND specialist nurses
Describe the pharmacological management of MND.
- Riluzole: prolongs survival by a few months
- Hyoscine: for drooling
- Baclofen: for spasticity
- Anti-depressants
Define ‘Guillain-Barre syndrome’.
- Immune mediated demyelination of the peripheral nervous system
Give a ‘typical’ history of a person presenting with Guillain-Barre syndrome.
- Infection a couple of weeks previous (classically Campylobacter)
- Ascending weakness (proximal muscles affected first, affecting lower limbs before upper).
- Little sensory disturbance
- Arreflexia
- Cranial Nerve dysfunction -> diplopia
- Autonomic Dysfunction -> sweating, tachycardia, arrhythmias, urinary retention
What is Miller Fisher Syndrome?
- A variant of Guillain Barre syndrome
- Ophthalmoplegia, Ataxia, Arreflexia (eyes affected first)
- Descending paralysis
What investigations should you do if you suspect Guillain Barre syndrome?
- Nerve conduction studies = slow :(
- CSF: raised protein, normal WCC
- Anti-GM1 antibodies (in 25% of patients)
What is the management of Guillain Barre syndrome?
- IV immunoglobulin for 5 days
- Plasma exchange
- 85% will make a full recovery
Describe the pathophysiology of Myasthenia Gravis
- Autoimmune
- Antibodies to post-synaptic nicotinic acetylcholine receptors
- Interferes with muscular transmission
- Fatiguability due to fewer available AChRs at NMJ
Which antibodies would you find in a person with Myasthenia Gravis?
ACh-R (Acetylcholine receptor)
MuSK (Muscle-specific receptor Tyrosine Kinase)
Describe a typical patient with Myasthenia Gravis.
- Female
- 30-50 years old
- Other autoimmune diseases
How might a person with Myasthenia Gravis present?
- Increasing muscular fatigue
- In order:
> extra-ocular (ptosis, diplopia)
> bulbar (swallowing, chewing, dysphonia)
> face
> neck
> limbs (proximal)
> girdle
> trunk - Normal tendon reflexes > a brisk, one off muscle contraction is possible in normal and MG.
What is the ‘peek sign’ in the context of Myasthenia Gravis?
After 30 seconds of sustained forced eyelid closer, the patient is unable to keep the lids fully closed.
What is a ‘Myasthenic snarl’?
- May be observed when the patient attempts to smile.
- The snarl follows contraction of the middle portion of the upper lip while the upper mouth corners fail to contract.
What investigations should you do if you suspect Myasthenia Gravis?
- Antibodies: Anti-AChR, MuSK
- CT thorax -> thymus
- Ice test -> ice applied to affected lid + ptosis improves
- Tensilon (edrophonium test)
Describe the Tensilon (edrophonium) test.
- Very short acting anti-acetylcholinesterase
- Postive result shows improvement in muscular strength following administration
- Performed less frequently due to risk of life-threatening bradycardia
What are the implications if the Tensilon test is negative?
Lambert-Eaton Myasthenia Syndrome (AI or paraneoplasitc -> small cell lung cancer)
in LEMS, the neuron is unable to release enough acetylcholine for normal muscle function due to autoantibodies attacking the calcium channel that are necessary for acetylcholine release.
There will typically be not as much increase in muscle strength observed after edrophonium injection, if any, with LEMS.
What is the treatment for Myasthenia Gravis?
- Acetylcholinesterase inhibitors -> slow down re-uptake of ACh
eg. Pyridostigmine, Neostigmine - Immunosuppressants for relapses eg. Prednisolone, Azathioprine, Methotrexate
- Thymectomy
What are the cholinergic side effects of acetylcholinesterase inhibitors (with regards to myasthenia gravis)?
- Increased parasympathetic activation > increased salivation > lacrimation > sweats > vomiting > miosis
Describe what you might see in a Myasthenic Crisis?
- Weakness of respiratory muscles
- May need intubation and ventilation
- Treat with plasmapheresis / IV Ig
- Treat trigger -> infections, medications, post-op