Neurology Flashcards
Define transient Ischaemic attack (TIA)
Transient / temporary neurological dysfunction secondary to ischaemia without infarction; within 24hrs
Blood supply entering the brain with which arteries……
Internal carotid artery (ICA) - 90%
Vertebral (posterior) - 10%
Main cause of TIA
Carotid thrombo-emboli
Increased emboli risk when Px has Afib - Remember CHA2DS2 VASc score is used as stroke risk in Afib Px.
Risk factors for transient Ischaemic attack
HTN
Hypercholestraemia
T2DM
Afib
Obesity
IHD
Smoking
Ventricular septal defect
Sx of TIA
Slurred speech
Facial weakness
Limb weakness
Amaurosis fugax - temporary painless vision loss; usually one eye.
What signs are seen in TIA
Focal neurology: depending on which vessel is affected, have different signs
Anterior cerebral.A - Contralateral leg weakness
Middle cerebral.A - Contralateral body weakness + facial drooping forehead sparing + dysphasia
Posterior cerebral.A - Vision loss; contralateral hamonymous hemianopia
Vertebral.A - Cerebellar syndrome - D.A.N.I.S.H; +ve Ramberg test (sensory and motor ataxia)
Opthalmic/Retinal/Ciliary.A
Irregular pulse - if AFib is cause
Carotid bruit - suggests carotid artery stenosis
How do you initially differentiate between TIA and Stroke
Can’t tell until after recovery:
TIA —> Sx resolve <24hrs with no infarct
Stroke —> Sx last ≥24hrs with infarction
What investigation and Dx are needed for TIA
Clinical Dx; usually obvious if TIA/stroke is suspected
2 scoring systems that can be used:
FAST —> Face Arms Speech Time (public health campaign)
ABCD2 —> Age >60; BP >140/90; Clinical Sx unilateral weakness (2pt) / slurred speech (1pt); Duration Sx >1hr (2pt) / <1hr (1pt); DMT2 (1pt)
- refer to neurology ASAP (sig. increased risk of stroke)
Treatment for TIA
Acutely —> Aspirin
Prophylaxis long term/2º prevention —> Clopidogrel (75mg) and Atorvastatin (80mg)
Define stroke
AKA a Cerebrovascular accident.
Focal neurological defect lasting >24hrs with infarct
What types of stroke are there
Ischaemic (85%)
Essentially prolonged TIA
Lacunar Ischaemic stroke
Haemorrhagic (15%)
Ruptured blood vessel
Intracerebral
Subarachnoid
Extradural/epidural not considered haemorrhagic strokes
Causes of each type of stroke
Ischaemic stroke
Cardiac
Atherosclerosis; Carotid thrombo-emboli: thrombosis ± AFib embolisation, AFib, smoking, HTN, hyperlipidaemia
Vascular
Aortic dissection
haematological
Hypercoagubility; Antiphospholipid syndrome
Polycythaemia, sickle cell disease
Haemorrhagic stroke
Intracerebral
HTN, trauma
Subarachnoid
Berry aneurysm rupture, trauma
Intraventricular
* - bleeding within the ventricles; prematurity is a very strong risk factor in infants*
Risk factors for stroke
TIA
HTN
Smoking
Obesity
T2DM
AFib
Hypercoagulability; polycythaemia, sickle cell
Sx of a stroke
Focal neurology like TIA
+ For haemorrhagic stroke
Increased ICP —> Midline shifts; risk of tentorial herniation (the movement of brain tissue from one intracranial compartment to another.)
+ For lacunar strokes
V. Common type of Ischaemic stroke of lenticulostriate arteries (branches of MCA;supplying deep structures) —> ischaemia to basal ganglia, internal capsule, thalamus & pons
If a Px is on oral anticoagulants - suspect haemorrhagic stroke.
What are the focal neurology signs *esp witnessed in a stroke/TIA *
Focal neurology = neurological defect; depending on which vessel is affected, presents with different signs
Anterior cerebral.A - Contralateral leg weakness
Middle cerebral.A - Contralateral body weakness + facial drooping forehead sparing + dysphasia
Posterior cerebral.A - Vision loss; contralateral hamonymous hemianopia
Vertebral.A - Cerebellar syndrome - D.A.N.I.S.H; +ve Ramberg test (sensory and motor ataxia)
Opthalmic/Retinal/Ciliary.A - Amaurosis fugax
Name a specific sign in stroke
Pronator drift
Ask a Px to lift arms to ceiling; pronators takeover so the arm of the affected side will pronate and the palm of hand faces down.
Investigation and Dx of stroke
G.Standard: Non-contrast CT head
Ischaemic stroke - usually normal
Haemorrhagic stroke - hyperdense blood
Could do MRI as alternative.
1st line: FBC, serum glucose, electrolytes, cardiac enzymes, PTT
± CT angiogram
Tx for stroke
Ischaemic
When presented within 4.5hrs —> use CLOT BUSTER / fibrinolytic agent (Alteplase)
+ Aspirin
Haemorrhagic
Neurosurgery referral
IV Mannitol (for increased ICP)
2º prevention / prophylaxis for both: atorvastatin + Clopidogrel; could give Ramipril for haemorrhagic stroke.
What does the DVLA say about strokes / TIAs
For cars/motorcycle:
Must not drive for 1month after TIA/strokes
For heavy vehicles:
Must not drive for 1 year
What classification is used to categorise a stroke according to area affected
Bamford classification
What does D.A.N.I.S.H acronym stand for and when is it used
Dysdiadochokinesis
Ataxia
Nystagmus
Intention tremor
Scanning dysarthria
Heel-shin test positivity
Used for cerebellar syndrome
A 38-year-old female presents by ambulance with a severe occipital headache, which started suddenly 1 hour ago. She collapsed due to the pain. She has a history of hypertension.
What is the most likely Dx
Subarachnoid haemorrhage
Describe the Pathophysiology of subarachnoid haemorrhages
Type of intracranial haemorrhage characterised by blood within the subarachnoid space where the cerebrospinal fluid is located (inbetween pia mater and arachnoid mater)
What are the causes of a subarachnoid haemorrhage
Trauma
Atraumatic (i.e. spontaneous)
Ruptured berry (/ saccular) aneurysm
Describe what a berry aneurysm is and what it can cause
Known as berry aneurysm as it looks like a berry off a vine.
Arise at points of arterial bifurcation within the Circle of Willis; most commonly junction between the anterior communicating and anterior cerebral arteries
Risk factor for subarachnoid haemorrhages
Traumas
Htn
Polycystic kidney disease
FHx
Increased age
Marfan’s/EDS
Signs and Sx of subarachnoid haemorrhages
Occipital thunderclap headache
Sudden onset
“The worst headache of my life”: 0–>10 severity instantly
Meningism (photophobia + neck stiffness)
Kernig sign - when hip and knee are flexed, hard to extend knee again
Brudzinski sign - automatic knee flexion when neck is flexed - Severe neck stiffness causes a patient’s hips and knees to flex when the neck is flexed
Reduced GCS
Nerve palsies (CN3-6)
Cn3 - fixated eye pupils
Cn6 - non-specific sign of increased ICP
What type of headache might be experienced preceding a berry aneurysm rupture
Sentinel headache
precedes the rupture by weeks ≈50% of cases - throbbing occipital pain
What is the differential Dx of subarachnoid haemorrhage
Meningitis (no thunderclap headache but w/ signs of infection)
Migraine (no meningism / thunderclap)
What is GCS referring to…
Out of /15
Eyes /4
Verbal /5
Motor /6
15: normal
≤ 8: comatose
≤ 3: unresponsive
Investigations and Dx of subarachnoid haemorrhages
Diagnostic - non-contrast CT Head
- ‘STAR shape’ on superior view
If positive: CT Angiogram - to see extent of rupture
If negative: Lumbar puncture - wait ~12hrs; results are most sensitive >12hrs
- Will see Xanthocheomia (yellowish CSF due to RBC haemolysis)
Treatment for subarachnoid haemorrhages
1st line:
Neurosurgery referral; endovascular coiling
+ Nimodipine (* CCB; decreased vasospasms + decreased BP*)
Define subdural haemorrhage
When blood accumulates between the dura mater and arachnoid mater (subdural space)
There’s bridging veins in that area; blood from the brain —> dural venous sinuses
Rupturing these veins (“in surgery is known as a very bad thing ;) loveland jk !”) and usually due to shearing injury (met with pressure and separation of the 2 layers)
Risk factors for subdural haemorrhages
Trauma
Child abuse - shaken baby syndrome
Increased age (Cortical atrophy e.g. dementia)
Signs and Sx of subdural haemorrhages
Acute sx incited within 3 days of an incident
Reduced conciousness
Headaches & vomiting
Signs of increased ICP - CUSHING TRIAD + papilloedema
* - Widened pulse pressure, bradycardia, reduced respiration*
chronic
Start seeing focal neurological deficit (CN3 palsy)
Investigation and Dx of subdural haemorrhage
Non contrast CT head:
Banana / crescent shaped haematoma; not confined to suture lines, midline shift
- If acute = hyperdense (bright)
- if subacute = Isodense
- if chronic (late) = hypodense (darker than the brain image)
Tx for subdural haemorrhage
Surgery; Burr hole + craniotomy
To reduce ICP: IV mannitol
Complication of subdural haemorrhage
Brain stem herniation
+
Respiratory arrest
Define extradural haemorrhage
Haematoma found within the potential space and dura mater.
What is the most common cause of an extradural haemorrhage
Trauma
Mainly leads to arterial bleeding - middle meningeal artery
Due to damage of the pterion (thinnest part of the skull) / temporal region
Risk factors for extradural haemorrhages
Seen in 20-30y/o
As age increases, risk decreases… as the dura is more firmly adhered to the skull
Head trauma
Signs and Sx of extradural haemorrhages
Acutely
Initial loss of consciousness —> lucid intervals of feeling okay —> rapid deterioration because of ICP
Reduced GCS
Increased ICP signs; Cushing triad (bradycardia, widened pulse pressure, irregular breathing) + papilloedema
What causes the rapid deterioration in extradural haemorrhages…
Increased ICP
Blood clots become haemolysed and take up water (i.e. they’re osmotically active) so they increase in volume, increasing the pressure.
Complication of extradural haemorrhages
Death for respiratory arrest
- herniation + coning of the brain = compressed respiratory centres
- due to untreated ICP
Investigation and Dx of extradural haemorrhage
Non-Contrast CT head
Lens shaped hyperdense bleed.
Confined to suture lines
Midline shift
Tx for extradural haemorrhages
Urgent surgery
IV mannitol to decrease ICP
What types of headaches are there….
1º headaches
Migraines
Cluster
Tension
Trigeminal neuralgia
Drug overdose
2º headaches cause is more specific; coz of an underlying condition
Giant cell artiritis
Infection
Head injury — subarachnoid haemorrhage
Carbon monoxide poisoning
Give an example of primary headaches
Tension
Cluster
Migraines
Trigeminal neuralgia
Drug-induced
Give an example of secondary headaches
Giant cell arteritis
Meningitis
Subarachnoid haemorrhages
Carbon monoxide poisoning
Give 6 questions you’d ask that are important when taking a history for a headache
Time; Onset / Duration / Frequency / Pattern
Triggers; any factors aggravating / alleviating the headaches
Type of pain; Severity / Site / Does pain spread? / Is it impacting QoL?
Associated Sx; Photophobia, Phonophobia, V&N
Response; to medication
Sx in between attacks
Give red flags for more serious conditions (raised ICP/intracranial haemorrhage) when presenting with a headache
Rapid/new onset headache
Fever + neck stiffness
Seizures
Papilloedema
Significantly altered consciousness / confusion
Describe the pain of a migraine
Unilateral
Throbbing
Moderate—>Severe
Worsened on exercise
±
Photophobia / phonophobia
N &/ V
Types of migraine
Episodic with Aura (20%) / without Aura (80%)
Chronic
May also have:
Silent migraines
migraines with aura but without headache
Hemiplegic migraines
Migraine mimicking a stroke; typical Sx of migraine + hemiplagia (unilateral weakness of limbs)
What do Px with migraine + aura complain of …
Visual disturbance / phenomena; ZIGZAG lines
Sparks in vision
Blurring vision
Lines across vision
Loss of different visual fields
What triggers are there for migraine
CHOCOLATE
C . Hocolate
Oral contraceptives
Cheese
AlcohO . L
Anxiety
Travel
Exercise
How long does migraine last
Prodrome (stage before the headache); mood ∆
± Aura (part of the attack, minutes before the headache)
Throbbing headache
4 - 72hrs
With a women complaining of migraines and is on oral contraceptive… what would you do as her dr
Stop O.C.
Offer alternatives; as it acts as a trigger, increases stroke risk, decreases Triptan efficacy
Investigation and Dx of migraine
Dx: clinical; unless a different pathway is suggested
The clinical Sx (Should meet this requirement):
≥2 of…
Unilateral pain
Throbbing
Moderate —> severe
Motion-sickness
+
≥1 of…
N &/ V
Photophobia / Phonophobia
with normal neuro exam
Tx for migraines
Acute
Oral Triptan (Sumotriptan)
Or
Aspirin 900mg
Prophylaxis
Beta-blocker (propanolol); if asthmatic give Topiromate (anti-convulsant)
Amitryptiline (TriCyclic Antidepressant)
Avoid Opiates
Consider Anti-emetics; Metoclopramide (if N &/V)
What drug class is Triptan
5-HT receptor agonist (serotonin receptor agonists)
MoA of Triptans and what condition can they be used in
Smooth muscle in arteries to cause vasoconstriction
Peripheral pain receptors to inhibit activation of pain receptors
Reduce neuronal activity in the central nervous system
- Headaches; migraines / cluster headaches
What are the pharmacological and non-pharmacological prophylaxis for migraines
Pharmacological
Propanolol (B. Blocker) / topiromate (anti-convulsant)
Amitryptiline
Non-Pharmacological
Acupuncture
Vit B supplement (riboflavin)
Wheat is the most common type of 1º headache
Tension headaches
Describe the pain of a tension headache
Bilateral
Generalised pain; pressing/tight
Mild —> moderate
Not exercise induced
Pain in Frontalis, temporalis and occipitalis muscles
Rubber band, tight around head
What is the duration of a tension headache
30 mins —> 7days
Excluding the generalised pain in tension headaches, are there any other sx
No
No motion sickness
No aura
No photophobia / phonophobia
Tx for tension headache
Analgesia:
Aspirin or paracetamol
Avoid opiates - dependence
Describe the pain of a cluster headache
Unilateral
Pain around an eye / temporal area
Severe —> very severe
Headache is accompanied by cranial autonomic features
Classified as Trigeminal Autonomic Cephalgia (TAC) - thought to happen because of hypersensitivity of trigeminal autonomic reflex arc (vascular dilation + nerve stimulation) & increased histamine release from mast cells — adding to the Sx
How long do cluster headaches last
15 min —> 3hrs
What is the most disabling 1º headache
Cluster headaches
Risk factors of cluster headaches
Male
Smoking
Genetics
Signs and Sx of cluster headaches
Crescendo unilateral peri-orbital excruciating pain - AKA suicide headaches
With ipsilateral autonomic features
Ptosis (droopy eye);
miosis (constricted unilateral pupil);
lacrimation (watery blood shot eyes);
rhinorrhoea (runny nose)
Investigation and Dx of cluster headaches
Clinical Dx; ≥ 5 similar attacks confirms Dx
But remember these headaches come in clusters and so they may experience Sx for like a week — month but then not experience them for years before the next cluster.
Tx of cluster headache
Acute
Triptans; Sumatriptan
High flow O2 (can be given at home)
Prophylaxis
Verapamil (CCB)
Describe the pain of Trigeminal neuralgia
Unilateral electric shock pain
Across the face (V1, 2, 3) - mainly V3 is affected
Very severe
What are the branches of trigeminal nerve
Cranial nerve 5
V1 —> Opthalmic
V2 —> Maxillary
V3 —> Mandibular
What is the duration of pain for trigeminal neuralgia
A few seconds
(Secs —> 2mins)
Name some triggers of trigeminal neuralgia
Eating (spicy foods / citrus fruit)
Cold weather
Brushing teeth
Talking
Name 3 risk factors for trigeminal neuralgia
Multiple sclerosis
Increased age
Female
Investigations and Dx of trigeminal neuralgia
Clinical; ≥ 3 attacks of the Sx
Tx for trigeminal neuralgia
Carbamazepine (anti-convulsant)
Surgery if all else fails
Define giant cell arteritis
Systemic vasculitis affecting large arteries; esp. temporal arteries
Key complication of giant cell arteritis
Vision loss (amaurosis fugax )
HIgh dose steroid used to prevent development/progression of the vision loss
Which condition does giant cell arteritis have a strong link with
Polymyalgia rheumatica
What are the sx of giant cell arteritis
Severe Unilateral scalp tenderness and headache around temple and forehead
Jaw claudication
Blurred / double vision (curtains over field of view)
Investigation and Dx of giant cell arteritis
Temporal artery biopsy (do a big sample to capture as many skip lesions):
Granulomatous non-caseating inflammation of intima+media; with skip lesions — multinucleated giant cells
Raised ESR / CRP
Normacytic normochromic anaemia
Tx of giant cell arteritis
Corticosteroids (prednisolone)
Any signs of amaurosis fugax —> high dose methylprednisolone STAT
Define epilepsy
Neurological disorder characterised by recurrent seizures.
Seizure = paroxysmal alteration of neurological function leading to hypersynchronous discharge of neurons within the brain
(I.E. sudden uncontrollable burst of electrical activity)
What types of seizures are there?
Generalised seizures:
Motor seizures;
Tonic-clonic seizures; Typical epileptic seizure
Tonic - stiffening of arms, leg / trunk
Clonic - Jerking of arms/legs on 1 or both sides of body
Non-Motor seizures;
Absence seizures
Focal seizures
Simple
Complex
Myoclonic - Some or all of body twitches lasting < 1sec.
Atonic - Sudden loss of muscle strength (floppy). Can cause person to drop to the ground. - THESE CAN BE GENERALISED / FOCAL
Define tonic-clonic seizures
AKA ‘Grand male’
Typically, tonic comes before clonic!
Generalised seizures involve both hemispheres of the brain at onset
- No aura
- Tonic phase; muscle tensing/Rigidity, so fall to the floor
- Clonic phase; muscle jerking
You see… Upgazing open eyes, incontinence, tongue-biting
Define an absence seizure
Generalised seizures involve both hemispheres of the brain at onset
Manifests in childhood; moments of blankly staring into space (secs—>mins) then carrying on from where they left / repeated movements like lip-smacking
What’s seen on an EEG of an absent seizure
3Hz spike
What can cause seizures
Remember V.I.T.A.M.I.N…D.E
Vascular
Infection
Trauma
Autoimmune conditions (SLE)
Metabolic (hypocalcaemia)
Idiopathic —> EPILEPSY
Neoplasm
Dementia / Drugs
Eclampsia
Define epilepsy relative to its seizures
Epilepsy = idiopathic cause of seizures
≥2 episodes more than 24hrs apart
Risk factor for epilepsy
Inherited
Family Hx
Metabolic disorders
Acquired
Dementia
Ischaemic stroke
What’s the difference between epileptic and non-epileptic seizures
Eyes open
Synchronous movement
Can occur in sleep
For epileptic seizures
Pathophysiology of an epileptic seizure
Imbalance between excitation (glutamate) and inhibition (GABA) within the neurons of the brain…
Balance shifts towards the excitatory neurotransmitter (glutamate) by stimulation + inhibition of GABA
Describe what a seizure period is
Pre-ictal
Aura / deja vu / triggers
Ictal
Seizure
Post-ictal
headache / confusion / reduced GCS / amnesia
TODD’s paralysis; if motor cortex affected (frontal lobe), may have temporary paralysis / muscle weakness
Define a focal seizure
Features are confined to a specific region; depending on which lobe of the brain is affected will depend on the Sx experienced
- Could progress to 2º generalised seizures
Simple focal; Px is Awake and Aware, just got uncontrolled muscle jerking
Complex focal; Px is Unaware / has impaired consciousness during the seizure.
What is jacksonian march
If jerking activity starts in specific muscle group and spreads to surrounding muscle groups as more neurones are affected its referred to as a JACKSONIAN MARCH.
Usually from more distal areas towards the face
What sx are seen if temporal region of brain is affected in epilepsy
Temporal lobe i.e., Memory, understanding speech, emotion
• Aura (80%); Deja-vu, auditory hallucinations, funny smells, fear
• Automatisms e.g., lip smacking
What sx are seen if frontal region of brain is affected in epilepsy
Frontal lobe i.e., Motor, thought processing
• Motor features e.g., posturing, peddling movements of leg
• JACKSONIAN MARCH – seizures march up/down the motor homunculus
• Post-Ictal Todd’s palsy
• Starts distally in a limb & works its way upwards to the face
What sx are seen if parietal region of brain is affected in epilepsy
Parietal lobe i.e., Sensation
• Sensory disturbances e.g. tingling/numbness
What sx are seen if occipital region of brain is affected in epilepsy
Occipital lobe i.e., Vision
• Visual phenomena e.g. spots, lines, flashes
Most common lobe saffected in epilepsy
Temporal
What investigation and Dx are the for epilepsy
Blood glucose, FBC Electrolyte panel, Tox screen, CSF lumbar puncture analysis- rule out other potential causes
MRI/CT head
Electroencephalogram (EEG)- not diagnostic but can help support diagnosis and may help determine type of epileptic syndrome
Tx of epilepsy
Generalised:
Tonic-clonic
1st line:Sodium valproate
2nd line: Lamotrigine
Absence
1st line:Sodium valproate
2nd line:Ethosuximide
Focal:
1st line: Lamotrigine
2nd line: Carbamazapine
Complication of generalised seizures
Status epilepticus
-It is a medical emergency. It is defined as seizures lasting more than 5 minutes or more than 3 seizures in one hour.
Tx:
A-E approach
Give Benzodiazepine IV lorazepam; repeated after 10 minutes if seizure continues
Define syncope
Insufficient blood / oxygen supply to the brain causing paroxysmal changes (periodic marked changes) in behaviour, sensation and cognitive processes
Give 5 signs that transient loss of conciousness is due to syncope
Situational
5 - 30 secs
Pallor
Nausea
Sweating
Dehydration
Which seizure is likely to last longer: epileptic / non-epileptic seizure
Non-epileptic *lasts around 1-20 mins
Whereas epileptic lasts around 30-120 secs*
A Px complains of having black-outs. They tell you before the black out they felt nauseous and were sweating. They tell you that their friends all said they looked pale. Is this a blood circulation problem or a disturbance of brain function
Likely to be a blood circulation issue e.g. syncope
How does carbamezapine work as an anti-epileptic drug
Inhibits pre-synaptic Na+ channels and so prevents axonal firing
What’s the major side effect of sodium valproate
Teratogenic
What is dopamine produced from
Tyrosine —> L-DOPA —> Dopamine
Define Parkinson’s disease
Loss/degeneration of dopaminergic neurones in the substantia niagra, pars compacta
Pars compacta is a sub-portion of substantia niagra
- 2nd most common neurodegenerative disorder
- Idiopathic
Where is substantia niagra found and where does the substantia niagra project to
Found on either side of the midbrain and part of the basal ganglia
Project to the Striatum (which consists of Caudate + Putamen)
The Pars compacta sends messages to the striatum via neuron rich neurotransmitter dopamine.
- Forming nigrostriatal pathway; helps stimulate cerebral cortex to initiate movement by signalling striatum to stop firing to pars reticulata to then stop movement inhibition
The other region of substantia niagra (pars reticulata) receives signals from the striatum which are then relayed to the thalamus using neurons rich in neurotransmitter GABA; which send signals to cortex to inhibit movement
Pathophysiology of Parkinson’s
The Pars compacta sends messages to the striatum via neuron rich neurotransmitter dopamine.
- Forming nigrostriatal pathway; helps stimulate cerebral cortex to initiate movement by signalling striatum to stop firing to pars reticulata to then stop movement inhibition
The other region of substantia niagra (pars reticulata) receives signals from the striatum which are then relayed to the thalamus using neurons rich in neurotransmitter GABA; which send signals to cortex to inhibit movement
Degeneration of substantia niagra pars compacta means reduced signalling so harder to initiate movement.
Risk factor for Parkinson’s
FHx
Increased age (since its progressive)
Males
Aetiology of Parkinson’s
Idiopathic
May be genetic; Mutation in PINK1 / Parkin / ∂-synuclein
Rare: Parkinsonians Sx may be caused by recreational drugs (MPPP)
Signs and symptoms of Parkinson’s
Cardinal Sx:
TRIAD; Tremor, Rigidity, Bradykinesia
+ Postural instability
Tremor; Pill-rolling resting tremor
Rigidity; Cogwheel rigidity = tension in arms/legs when passively moved gives movement in small increments (jerk movement)
Bradykinesia; Shuffling gait as a result of Bradykinesia and Hypomimia - reduced facial expressions
+ Amnosia
Would you describe the Parkinson’s Sx as symmetrical or asymmetrical
One side is always worse than the other
- Sx are asymptomatic / unilateral
Investigation and Dx of Parkinson’s
Clinical
(Bradykinesia + ≥1 cardinal sign)
Give a differential Dx for Parkinson’s
Lewy body dementia (associated with Parkinson’s)
Parkinson’s Sx then dementia = Parkinson dementia
Parkinson’s Sx after dementia = Lewy body dementia with Parkinsonism
Tx of Parkinson’s
Doesn’t stop neurodegeneration; helps with Sx
Main aim is to increase dopamine signalling in the brain
Dopamine doesn’t cross the Blood-Brain Barrier… its precursor Levadopa does; converted in the brain to dopamine by decarboxylase inhibitor; carbidopa - given as combination with L-Dopa; Co-careldopa - but theres also peripheral dopa decarboxylase which converts dopamine —> epinephrine… we dont want this so use decarboxylase inhibitors as that’ll stop dopamine breakdown and wont pass the BBB either.
L-Dopa + decarboxylase inhibitor (carbidopa) = Co-careldopa
Could also give:
Dopamine agonist - Bromocriptine / Cabergoline
Can also give enzyme inhibitors to stop dopamine breakdown in different pathways
COMT inhibitors - Entacapone
MAO inhibitors - Selegiline
You ask a Px who you suspect might have PD to walk up and down the corridor so that you can assess their gait. What features would be suggestive of PD
Stooped posture
Assymetrical arm swing
Small steps
Shuffling
Histological findings in Parkinson’s disease
Lewy bodies
Loss of dopaminergic neurones in substantia niagra
Give an example of a dopamine agonist
Bromocriptine
Cabergoline
Give an example of a COMT inhibitor
Entacapone
Give an example of a MAO inhibitor
Selegiline
Give side effects of levodopa
Dyskinesia (involuntary movement)
Has an “on/off” effect i.e. there’ll be well controlled periods w/ sudden declines
Define huntington’s chorea
Autosomal dominant genetic disorder trinucleotide repeat that causes progressive deterioration of the nervous system
What mutation is found in Huntington’s chorea
Trinucleotide repeat disorder; genetic mutation in HTT gene on chromosome 4
What triplet code is repeated in Huntington’s disease
CAG triplet repeats
≥36 times
Define anticipation
Genetic anticipation is a feature seen in trinucleotide repeats.
As generation earlier age onset
The more repeats, the increased severity of disease
Pathophysiology of Huntington’s
The trinucleotide repeat (of CAG) leads to mutated HTT proteins formation but they also affect the DNA replication itself.
These can aggregate in neuronal cells of the basal ganglia (caudate nucleus; striatum) causing neuronal cell death.
Neurotransmitter affected = GABA (lack of) + excessive nigrostriatal pathway
What features and signs are seen in Huntington’s
Early onset
Irritability
Depression
Personality change
Later onset
Chorea (fidgety)
Athetosis (slow involuntary movement)
Psychiatric problems
Dementia
Investigation and Dx of huntingtons
Clinical; FHx of earlier + severe huntingtons
Genetic test to count CAG repeats
Tx for Huntingtons
Extensive counselling
Medication
Dopamine antagonist for chorea; Tetrabenazine
Could also give:
Antipsychotics; Olanzapine
Benzodiazepines; Diazepam
Define multiple sclerosis
Chronic autoimmune, cell-mediated demyelinating disease of the CNS.
Epidaemiology of multiple sclerosis
Females
20-40y/o
Rare in the tropics
Risk factors for multiple sclerosis
Other autoimmune conditions
Female
20-40y/o
EBV
Describe the aetiology of multiple sclerosis
Environmental
Genetic predisposition
Idiopathic
Pathophysiology of multiple sclerosis
Genetic susceptibility + environmental trigger —> T-Cell activation —> B-cells and macrophage activation —> Inflammation, demyelination and axon destruction
Where would the plaques be seen histologically
Around blood vessels; perivenular
Does myelin regenerate in someone with multiple sclerosis
Yes but its much thinner which causes inefficient nerve conduction
Give 3 main features of MS plaque
Inflammation
Demyelination
Axon loss
What types of multiple sclerosis is thee
Relapsing - remitting
Sx; the Px has random attacks over a number of years and inbetween the attacks theres no progression
1º progressive
Gradual deterioration without recovery
2º progressive
Relapsing-remitting —> 1º progressive
Signs and Sx of multiple sclerosis
Symptoms:
Paraesthesia
Blurred vision
Uhtoff’s phenomenon - worsening Sx following a rise in temperature (hot shower)
Signs:
Optic neuritis (inflamed optic nerve + can’t see red properly) —> 1st presenting Sx
