Neurology COPY COPY Flashcards
What is a cerebrovascular accident?
Ischaemia or infarction of brain tissue secondary to inadequate blood supply
OR
Intracranial haemorrhage
What are the different types of cerebrovascular accidents?
Transient Ischaemic Attack(TIA)
Stroke:
Haemorrhagic
Ischaemic
What is a TIA?
Sudden onset focal neurological deficit with complete clinical recovery secondary to ischaemia without infarction.
Sx Last <24 hrs
Caused by Reduced blood flow, ischaemia, embolism or disease of blood vessels or blood.
What is a crescendo TIA?
where there are two or more TIAs within a week. This carries a high risk of developing in to a stroke.
What is the epidemiology of a TIA?
15% of first strokes are preceded by TIA
M > F
Black ethnicity is at greater risk due to their hypertension and atherosclerosis predisposition
20, 000 people have a TIA
What are the risk factors for a TIA?
Increasing age
Hypertension
Smoking
Diabetes
Hypercholesterolaemia
Atrial fibrillation
HTN
VSD
Carotid stenosis
What are the causes of a TIA?
Thrombus formation or embolus (for example in patients with atrial fibrillation)
Atherosclerosis + embolism from carotid
Shock
Vasculitis
Hyper viscosity - polycythaemia, sickle cell, myeloma
What artery is commonly the route of a TIA?
90% = ICA
10% = Vertebral
What are the Clinical features of a TIA?
Depends on the site of the TIA:
- Sudden Loss of function with complete recovery
- Stroke Sx - Slurred Speech Facial Droop
- 90% of TIAs affect anterior circulation (ICA)
- 10% affect Posterior Circulation (vertebral Arteries)
What would be the signs of a TIA in the Anterior Cerebral artery?
Weak/numb contralateral leg
What would be the signs of a TIA in the Middle Cerebral Artery?
weak/Numb contralateral side of body
Face drooping w/ forehead spared
Dysphasia
What would be the signs of a TIA in the Posterior Cerebral Artery?
Vision loss:
Contralateral homonymous hemianopia w/ macula sparing = occipital cortex affected.
What would be the signs of a TIA in the Vertebral Artery?
Cerebellar Syndrome: DANISH w/ +tve romberg test
Dysdiadokinesia
Ataxia
Nystagmus
Intention tremor
Slurred staccato speech
Hypotonia
What is Amaurosis Fugax?
a painless temporary loss of vision, usually in one eye
Due to occlusion/reduced blood flow to the retina through the ophthalmic, retinal or ciliary artery. (often due to emboli)
This is a bad sign as it often signals stroke is impending
What is the Primary investigation for a TIA?
Diagnosis is Clinically made: Usually TIA/Stroke is obvious
ABCD^2 assessment
FAST test
MRI - First line for confirmation
Carotid Doppler - Look for Stenosis
CT angiography - Look for Stenosis
ECG
What is the FAST acronym?
FACE
ARMS
SPEECH
TIME
What is the ABCD^2 scoring system for TIA/Stroke?
No longer recommended by NICE
Age >60
BP >140/90
Clinical Sx - Unilateral Weakness (+2). Speech Disturbance w/o weakness (+1)
Duration >1hr (+2) / <1hr (+1)
DM - Type 2
What would be a high or low risk score following ACBD^2 assessment for TIA/stroke?
High risk:
ABCD2 score of 4 or more
AF
More than TIA in one week
TIA whilst on anti-coagulation
Low risk:
None of the above
Present more than a week after their last symptoms have resolved
How can you distinguish between a TIA and a Stroke?
You cant until after recovery
TIA Sx resolve usually within/<24 hours
Stroke Sx last more than 24 hours
What is the management of a High and low Risk TIA?
Lower RFs - stop smoking, reduce alcohol, exercise and diet
Immediate Aspirin 300mg
Start secondary prevention of CVD:
Clopidogrel 75mg
Atorvastatin 80mg
Treat BP - Ramipril
High Risk - Refer for specialist assessment within 24 hours of onset of symptoms
Low Risk - Refer for specialist assessment within 7 days of onset of symptoms
What are the main complications of a TIA?
Increased risk of stroke
Increased risk of underlying CVD
What are the two types of stroke?
Ischaemic (85% of cases)
Haemorrhagic (15% of cases)
Define a stroke?
Rapid onset neurological deficits caused by focal, cerebral, spinal or retinal infarction lasting more than 24 hrs
What is the epidemiology of a stroke?
1.2 million people living with stroke in the UK
110, 000 people have a first or recurrent stroke per year
Uncommon in those under 40
More common in males than females
Incidence is falling due to more vigorous approach to risk factors in primary care e.g. statin use and BP control
What is an Ischaemic Stroke?
85% of strokes
An episode of neurological dysfunction caused by focal cerebral, spinal or retinal infarction secondary to the occlusion of a blood vessel
What are the categories of Ischaemic Stroke?
Large Vessel Disease (50%) - Atherosclerosis
Small Vessel Disease (25%) - Lacunar
Cardioembolic (20%) - AF, IE, MI, Dissection
Cryptogenic (<5%)
Rare causes (<5%) - vasculitis
What are the main causes of Ischaemic stroke?
Large artery stenosis
Cardiac emboli from AF, MI or infective endocarditis 🡪 blood stasis
Atherothromboembolism e.g. from carotid artery
Dissection of aorta/carotid
Shock – reduced blow flow throughout body
Vasculitis
What is a Haemorrhagic Stroke?
15% of strokes:
Rapidly developing clinical signs of neurological dysfunction attributable to a focal collection of blood within the brain parenchyma or ventricular system not caused by trauma.
What are the subtypes of haemorrhagic stroke?
Primary Intracerebral: bleeding within the brain parenchyma
Subarachnoid Haemorrhage: bleeding into the subarachnoid space
Secondary haemorrhage (these are NOT strokes) - due to trauma, anti-coagulation (warfarin), Bleeding due to tumour
What are the main causes of a haemorrhagic stroke?
Hypertension
Aneurysm rupture 🡪 SAH
Arteriovenous Malformation (AVM)
Amyloidosis
What is the 3rd leading cause of mortality in the US and UK?
Stroke
What are the risk factors for stroke?
Hypertension - greatest RF
Increased age - 68-75 MC
Male
Smoking
Diabetes
Hypercholesterolaemia
AF
Heart disease
FHx
Medication
What are the symptoms of stroke?
Focal neurological deficit based on site of the infarct.
What would be an extra finding in haemorrhagic stroke?
Increased intracranial pressure (ICP)
Causes midline shift
What is a Lacunar Stroke?
Very common type of ischaemic stroke of the lenticulostriate arteries.
These supply the deep brain structures (BG, IC, Thalamus, pons)
What are the clinical manifestations of a stroke in the anterior cerebral artery?
Contralateral weakness of lower limb
Contralateral sensory loss of lower limb
Truncal ataxia
Incontinence
Drowsiness
Dysphasia (if dominant hemisphere)
Logical thinking
Personality
What are the clinical manifestations of a stroke in the Middle cerebral artery?
Contralateral motor weakness – arms and legs
Hemiplegia – paralysis of one side of the body
Contralateral sensory loss
Aphasia – inability to understand (Wernicke’s) or produce speech (Broca’s)
Dysphasia (speech problems) – only if stroke is in dominant hemisphere (Broca’s)
Facial droop
What are the clinical manifestations of a stroke in the Posterior cerebral artery?
Contralateral homonymous hemianopia with macular sparing
Visual agnosia
Disorders of Perception
What are the clinical manifestations of a stroke in the Vertebrobasilar artery?
Cerebellar signs
Reduced consciousness
Disorders of balance
Coordination disorders
Quadriplegia or hemiplegia
What are the clinical manifestations of a stroke in Weber’s syndrome (midbrain infarct; branches of posterior cerebral artery)
Oculomotor palsy and contralateral hemiplegia
What are the clinical manifestations of a stroke in Lateral medullary syndrome (posterior inferior cerebellar artery occlusion)
Ipsilateral facial loss of pain and temperature
Ipsilateral Horner’s syndrome
Ipsilateral cerebellar signs
Contralateral loss of pain and temperature
What is horner’s Syndrome?
Caused by a Lesion within the Sympathetic Pathway
Presents as a unilateral triad of:
Miosis: small pupil
Ptosis: drooping eyelid
Anhidrosis: lack of sweat
What are the clinical manifestations of a stroke in the Basilar Artery?
Locked in syndrome;
Paralysed except for muscles that control eye movements.
Px are consciously aware, can think and reason but cannot speak or move
What are the extra symptoms of a haemorragic stroke?
headache
AMS (altered Mental Status)
Seizures
N+V
What are the primary investigations for a stroke?
CT Head:
Ischaemic - mostly normal
Haemorrhagic - Hyperdense blood
Ix over first few days after stroke:
MRI - with diffusion weighted imaging
CT Angiography
Carotid Doppler USS
ECHO - for those with cardioembolic stroke
ECG - For AF
Bloods - rule out hypoglycaemia
What is the very first step in the acute management of a suspected stroke?
Determine if the stroke is haemorrhagic or ischaemic from the initial CT.
What is the management for an Ischaemic stroke?
immediate CT to exclude primary intracerebral haemorrhage
If presents within 4.5hrs:
Clot buster (thrombolysis) - IV Alteplase
Presenting After 4.5 hrs
Aspirin 300mg for 2 weeks
Prophylaxis - Lifelong clopidogrel (75mg)
What is the function of Alteplase?
What are the contraindications?
Tissue plasminogen activator that rapidly breaks down clots and can reverse the effects of a stroke if given in time.
CIs: Haemorrhage, Intracranial bleed, clotting disorders, aneurysms
What is the management of a Haemorrhagic Stroke?
Neurosurgery referral for larger bleeds
Control BP - BB/ARB to <150 systolic
Iv mannitol for increased ICP
Vitamin K if bleeding is warfarin related
rehabilitation - Physio/OT
What type of stroke should be suspected if the patient is on oral anticoagulants?
Suspect Haemorrhagic until proven otherwise
What are some key differential diagnoses for strokes?
Hypoglycaemia
Space occupying Lesions - tumour, AVM
Syncope due to arrythmia
Migraines
Functional Neurological Disorders
Infection - particularly in elderly
What is the prophylactic prevention of secondary strokes?
Clopidogrel 75mg once daily (alternatively dipyridamole 200mg twice daily)
Atorvastatin 80mg should be started but not immediately
Carotid endarterectomy or stenting in patients with carotid artery disease
Treat modifiable risk factors such as hypertension and diabetes
What is a haematoma?
Describes a bleed that has mostly clotted and hardened
What is a Haemorrhage?
Describes an active ongoing bleed
Where can intracranial haemorrhages occur?
Extradural
Subdural
Subarachnoid
Intracerebral
What are the main blood vessels within the meninges?
Extradural – middle meningeal artery
Subdural – bridging veins
Subarachnoid – circle of Willis
Pia – no vessels as it forms part of the blood-brain barrier
What is an Extradural (Epidural) haemorrhage (EHD)?
Bleeding into the potential space between the skull and the dura mater.
The blood then collects in this space and is referred to as an extradural haematoma (EDH).
What are the causes of Extradural haemorrhage?
Usually Trauma (blunt trauma):
Arterial bleed - often middle meningeal artery
Venous bleed - often due to dural venous sinus
What is the most common blood vessel damaged to cause an extradural bleed?
Middle meningeal artery due to damage to the pterygoid bone
What are some rarer causes of an EDH?
Non-traumatic:
Haemorrhagic tumour
Coagulopathy
Infection
Vascular Malformation
What are the risk factors for an EDH?
Younger age (20-30)
Male
Anticoagulant usage
Why is an EDH less likely to occur in the elderly?
The Dura matter is more firmly adhered to the skull so blood is less likely to accumulate in this region.
What is the typical presentation of an Extradural bleed?
Characteristic history:
Head injury
Loss of consciousness following trauma or initial drowsiness
Lucid interval – period of time between traumatic brain injury and decrease in consciousness
Signs of raised ICP – headache, vomiting, nausea, seizure
± hemiparesis with brisk reflexes
Cushing’s Triad - Bradycardia and raised BP and Respiratory Irregularity
Ispilateral pupil dilation
Decreased Glasgow coma scale
Coning of brain through foramen magnum
Death due to respiratory arrest
What are the cushings triad signs of an extradural haemorrhage?
Wide Pulse Pressure
Bradycardia
Respiratory irregularity
Why is there an increased ICP in an EDH?
Haemorrhage - increased volume decreased pressure
old blood clots which can then take up water (osmotically active)
Will increase in volume and raise ICP
What are the primary investigations of an EDH?
CT head:
Lens shaped hyperdense bleed/haematoma
Confined within suture lines
Midline shift
Skull XR - may show fracture
What is the management on an EDH?
Urgent Neurosurgery referral:
- Burr Hole craniotomy
Ligation of bleeding vessel
Stabilise Px - ABCDE management
IV Mannitol to reduce ICP
What are the complications of an EDH?
Cerebral oedema
Raised intracranial pressure and herniation
Ischameia: can occur due to mass effect, herniation, hypoperfusion, vasospasm
Seizures
Infection
What is the Typical History of an EDH?
The typical history is a young patient with a traumatic head injury that has an ongoing headache.
They have a period of improved neurological symptoms and consciousness followed by a rapid decline over hours as the haematoma gets large enough to compress the intracranial contents.
What are some Key differential Diagnoses of an EDH?
Subdural haematoma
Subarachnoid haematoma
Epilepsy
Meningitis
Carotid dissection
Carbon monoxide poisoning – fit with lucid period
What is a Subdural Haemorrhage?
When blood accumulates in between the dura and arachnoid matter often due to rupture of the bridging veins
What are the causes of a Subdural haemorrhage?
Often due to the rupture of a bridging vein caused by trauma:
Shearing deceleration injury
Abused children (shaken baby sydrome)
What is the Epidemiology of a Subdural Haemorrhage?
Often in Px who have small brains:
Alcoholics, Dementia, Children
Occurs in Abused Children (Shaken Baby Syndrome)
What are the risk factors for a subdural haemorrhage?
Increased age
alcoholics
Trauma
Cortical atrophy (due to age/dementia)
Child abuse
What is the pathology of a SDH?
- Trauma either due to deceleration due to violent injury or due to dural metastases results in bleeding from bridging veins between cortex and venous sinuses
- Bridging veins bleed and form a haematoma (solid swelling of clotted blood) between the dura and arachnoid
- This reduces pressure 🡪 bleeding stops
- Days/weeks later the haematoma starts to autolyse due to the massive increase in oncotic and osmotic pressure 🡪 water is sucked into the haematoma 🡪 haematoma enlargement 🡪 gradual rise in intra-cranial pressure (ICP) over many weeks
- This shifts midline structures away from the side of the clot and can lead to tectorial herniation and coning (brain herniates through foramen magnum) if left untreated
What are the symptoms of a subdural haemorrhage?
Often gradual symptom onset with a latent period (can be days, weeks, months)
Progressive confusion and cognitive deficit
Headaches and vomiting
Focal neurological deficit, e.g. weakness or fixed dilated pupil
Fluctuating consciousness
What are the clinical signs of a subdural haemorrhage?
Signs of Raised ICP - headache, N+V, Seizure
Cushing Triad - Wide PP, Bradycardia,
Resp irregularity
Fluctuating GSC
Herniation - Supratentorial and infratentorial
What are the primary investigations of a subdural haemorrhage?
CT Head:
Banana/Crescent shaped dense region.
Not confined to suture lines.
May have midline shift
If acute - Hyperdense (bright)
If Subacute - Isodense
If Chronic - Hypodense (darker than brain
What is the treatment for a subdural haemorrhage?
Referral To Neurosurgeon
IV mannitol - reduce ICP
Burr hole / Craniotomy to relieve pressure
What is a subarachnoid haemorrhage (SAH)?
Subarachnoid haemorrhage involves bleeding in to the subarachnoid space, where the cerebrospinal fluid is located, between the pia mater and the arachnoid membrane.
This is usually the result of a ruptured cerebral aneurysm.
What is the Epidemiology of a Sub Arachnoid Haemorrhage?
Typical age 35-65 – mean age 50
Account for ~5% of strokes
8-12 per 100, 000/year
What are the possible causes of an SAH?
Trauma
Non-Trauma: (spontaneous)
Berry Aneurysm from circle of willis- MC of spontaneous SAH (70%)
AVM
Where do berry aneurysms often occur?
Usually at junctions of arteries within the circle of Willis.
Often communicating junctions
What is the most common artery affected in an SAH?
Circle of Willis:
Anterior communicating artery
ACA junction
What are the risk factors for a SAH?
What are some strong associations with SAH?
Increased age - >50yrs
HTN
Known Aneurysm
PKD
Trauma
FHx
Smoking
Alcohol excess
Strong associations with Cocaine Use and Sickle Cell
What is the Pathology of an SAH from a Berry Aneurysm?
Rupture of the arteries forming the circle of Willis
Rupture of the junction of the anterior communicating artery and the anterior cerebral artery or the posterior communicating artery and the internal carotid artery
Leads to tissue ischaemia (since less blood can reach the tissue) as well as rapid raised ICP as the blood acts like a space-occupying lesion and puts pressure on the brain 🡪 neurological deficits
What is the Pathology of an SAH from an AVM?
Atriovenous malformations (AVM)
Vascular development malformation often with a fistula between arterial and venous systems causing high flow through the AVM and high-pressure arterialisation of draining veins 🡪 rupture
What are the symptoms of a SAH?
Occipital Thunderclap Headache
Seizures
Vomiting
Loss of Consciousness - Coma/Drowsiness
Meningism (mimics meningitis)
Reduced GSC
Nerve palsies - 3rd / 6th
What are the signs of an SAH?
Meningeal irritation:
- Kernig’s sign – unable to extend patient’s leg at the knee when the thigh is flexed
- Neck stiffness
- Brudzinski’s sign – when patient’s neck is flexed, patient will flex their hips and knees
Subhyaloid haemorrhages (bleeding between retina and vitreous membrane) ± papilloedema
What are the characteristics of the headache experienced in an SAH?
Occipital Thunderclap Headache
Sudden onset
Worst headache of their life (0-10 instantly)
May have a sentinel headache preceding this
Why may you get nerve palsies in SAH?
3rd nerve palsy:
An aneurysm arising from the posterior communicating artery will press on the 3rd nerve, causing a palsy with a fixed dilated pupil
6th nerve palsy:
A non-specific sign which indicates raised intracranial pressure
What are the primary investigations in a SAH?
CT Head - diagnostic with 100% sensitivity if performed within 6 hrs.
If Negative but SAH still suspected:
Lumbar Puncture (performed after 12hrs)
will show xanthochromia / yellowish CSF due to RBC haemolysis
Angiography (CT or MRI) can be used once a subarachnoid haemorrhage is confirmed to locate the source of the bleeding.
ABG - Rule out hypoxia
Who do SAHs more commonly affect?
Black patients
Female patients
Age 45-70
What is the Glasgow Coma Scale (GCS)?
Tool for assessing consciousness:
Based on Eyes, verbal and motor response.
Normal - 15/15
Comatose - 8/15
Unresponsive - 3/15
Eyes:
Spontaneous = 4
Speech = 3
Pain = 2
None = 1
Verbal response:
Orientated = 5
Confused conversation = 4
Inappropriate words = 3
Incomprehensible sounds = 2
None = 1
Motor response:
Obeys commands = 6
Localises pain = 5
Normal flexion = 4
Abnormal flexion = 3
Extends = 2
None = 1
What are important differential diagnoses of SAH?
Meningitis - no thunderclap headache in this
Migraine - no meningism/thundercap headache in this
What is the treatment for an SAH?
1st line:
Neurosurgery Referral:
1st - Endovascular coiling
2nd - Surgical clipping
Give immediate Nimodipine (CCB) 60mg (every 4 hrs for 21 days)- prevents vasospasm
Resuscitation
Monitoring for complications
What are some complications of an SAH?
Re-bleeding
Cerebral ischaemia - due to vasospasm
Hydrocephalus – due to blockage of arachnoid granulations
Hyponatraemia - due to urinary salt loss
What are some Differential Diagnoses of an SAH?
Migraine
Meningitis
Corticle vein thrombosis
What is an Intracerebral haemorrhage?
Intracerebral haemorrhage involves bleeding into the brain tissue. It presents similarly to an ischaemic stroke.
Often has a headache/come and signs of raised ICP
Define Meningitis?
Inflammation of the meninges
This is a notifiable condition to PHE
What are the different causes of Meningitis?
Viral:
Enterovirus (coxsackie)
HSV2
VZV
Bacterial:
N. Meningitidis
S. pneumonia
What is the most common cause of meningitis?
Viral cause
What organism is the most common cause of viral and bacterial meningitis?
Viral - Enterovirus (coxsackie)
Bacterial - S. pneumoniae
Which is a more severe form of meningitis?
Bacterial is more severe
What is the pathology of Meningitis?
- Brain and the CSF should be sterile – no bacteria
- Bacteria can get in through different routes:
- Neurosurgical complications: post-op, infected shunts, trauma
- Extracranial infection: ear – otitis media, nasopharynx, sinuses – sinusitis
- Via the blood stream: i.e. bacteraemic seeding
- Once the CSF is infected the pathogen can multiply and replicate because there are no immune cells (as the BBB prevents the movement from the blood)
- Eventually the WBCs enter into the CSF, meninges and brain due to the blood vessels becoming leaky
- This causes meningeal inflammation +/- brain swelling
What are the main risk factors for meningitis?
Extremes of age (Infant/elderly)
Immunocompromised
Pregnancy
Travel
Crowded environment - barracks/uni
Non-vaccinated
What is the most common bacterial cause of meningitis in neonates (0-3 months)?
Group B Strep (S. agalactiae)
Due to the colonisation of mothers vagina which can cause infection in neonate at birth.
Also E.coli and Listeria
What is the most common bacterial cause of Meningitis in Infants?
N. meningitidis
S. pneumoniae
H. Influenzae (now rare due to vaccine)
Why is Haemophilus influenzae now a less common cause of meningitis?
Due to vaccination
What are the common bacterial causes of meningitis in adults?
S. pneumoniae
N. Meningitidis
What are the most common bacterial causes of meningitis in the elderly?
S. pneumoniae
N. meningitidis
Listeria
What are the most common bacterial causes of meningitis in the immunocompromised?
Listeria monocytogenes
M. Tuberculosis
What vaccines are available for meningitis coverage?
N. Meningitidis - Men B + Men C + Men ACWY
S. pneumoniae - PCV Vaccine
What is meningococcal Septicaemia?
N. meningitidis infection in the blood.
This causes a non-blanching purpuric rash
This is due to Disseminated intravascular coagulopathy (DIC) and subcutaneous haemorrhages
What are the symptoms of Meningitis?
Meningism:
Headache, Photophobia, Neck stiffness
Fever
Nausea + Vomiting
Seizures
Purpuric Rash - Bacterial Meningitis
Non-Blanching Purulent Rash - Meningococcal Septicaemia
What are the clinical signs of meningitis?
Kernig’s Sign:
When the hip is flexed and the knee is at 90°, extension of the knee results in pain
Brudzinski Sign:
severe neck stiffness causes the hips and knees to flex when the neck is flexed
What are the primary investigations in meningitis?
Bloods:
FBC - raised WCC
CRP - raised
Blood glucose - compared with CSF
Blood culture - to determine viral/bacterial
CT Head - Look for Brain Lesions/Abscesses/CIs for LP
GS DIAGNOSTIC = Lumbar Puncture (LP) + CSF Analysis
What are some contraindications for a lumbar puncture?
Raised ICP
GCS <9
Focal Neurological signs
Where is a lumbar puncture usually taken from?
Between L3/L4
Since spinal cord ends L1/2
What would the results of an LP CSF sample analysis look like in bacterial meningitis?
CSF:
Appearance - Cloudy
WCC - High neutrophils
Protein High
Glucose - Low
Culture - bacterial organism
bacteria swimming in the CSF (cloudy) will release proteins (high) and use up the glucose (low). Immune response to bacteria is neutrophils
What would the results of an LP CSF sample analysis look like in Viral meningitis?
CSF:
Appearance - Clear
WCC - High Lymphocytes
Protein - Normal/Mildly raised
Glucose - Normal
Culture - Negative
Viruses cant be seen (clear) don’t use glucose (normal) but may release a small amount of protein (normal/mild inc). Immune response to viruses are lymphocytes
What is the treatment for viral Meningitis?
Usually milder and so Supportive Tx
If HSV/VZV infection then Acyclovir
What is the treatment for bacterial meningitis in a hospital?
Broad Spec Abx - Cover All Likely Organisms:
1st Line - Ceftriaxone or Cefotaxime (as they get through the BBB)
WTIH OR AFTER
IV Dexamethasone - Prevent neurological sequelae
2nd Line: Chloramphenicol
Once Blood cultures have been done then can tailor Abx:
Eg. IV Benzylpenicillin for N.Meningitidis
What is the treatment for suspected meningitis w/ non-blanching rash present in the community?
Suspected Meningococcal infection:
Urgent/immediate IM Benzylpenicillin
Prior to immediate transfer to a hospital (unless it will cause a delay)
What are some complications of meningitis?
Hearing loss is a key complication
Seizures and epilepsy
Cognitive impairment and learning disability
Memory loss
Cerebral palsy, with focal neurological deficits such as limb weakness or spasticity
What are some Differential Diagnoses of Meningitis?
‘Worst headache ever’ - subarachnoid haemorrhage (especially if trauma, ‘thunderclap onset’)
migraine
Encephalitis
flu and other viral illnesses
sinusitis
brain abscess
malaria
What are some specific complications related to meningococcal meningitis?
Risk of DIC
Risk of Waterhouse Friedrichsen Syndrome
What is Waterhouse Friedrichsen Syndrome?
Adrenal insufficiency caused by intra-adrenal haemorrhage as a result of meningococcal DIC
What is the most common cause of fungal meningitis?
Cryptococcus Neoformans
Candida
Only really affects immunocompromised Px
What can be given to close contacts of a Px who has Meningitis?
Rifampicin
Ciprofloxacin
What is Encephalitis?
infection of the brain leading to inflammation of the brain parenchyma
What are the causes of Encephalitis?
Viral (most common)
Also bacterial, fungal, parasitic, paraneoplastic
What is the most common cause of encephalitis?
HSV-1
Accounts for 95% of the cases
Also CMV, EBV, HIV, VZV
What are the risk factors of encephalitis?
Immunocompromised
Extremes of age
Transfusion/Transplantation
Why can close contact with cats be a risk factor for encephalitis?
Risk of toxoplasmosis infection
What are the symptoms of encephalitis?
Px often has preceding flu like Sx
Triad Of:
Fever
Headache
Altered GCS: Behavioural changes/Psychotic behaviour/mood changes
Confusion
Focal Neurological deficit
Memory loss
Seizures
What are the clinical signs of encephalitis?
Pyrexia
Reduced GCS
Focal neurological deficit:
Aphasia
Hemiparesis
Cerebellar signs
What is the most common place to be affected by encephalitis?
Temporal and inferior frontal lobe
What are the primary investigations for encephalitis?
Bloods - FBC, CRP, U&Es
MRI head – to show swelling/ inflammation ± midline shifting due to raised ICP
EEG – shows periodic sharp and slow waves
Lumbar puncture (after): raised lymphocytic CSF, viral PCR
HIV TEST – acute phase viraemia can cause encephalitis
What is the treatment of encephalitis?
Mostly Supportive
IV Acyclovir - for HSV/VZV
What is multiple sclerosis?
Chronic progressive autoimmune, T-cell mediated inflammatory disorder of the CNS against the myelin basic protein of oligodendrocytes causing demyelination of CNS neurons.
It occurs sporadically over years
What type of reaction is MS?
Type 4 Hypersensitivity Reaction:
T-Cell mediated
What is the Epidemiology of MS?
Women to Men – 2:1
Usually diagnosed between 20-40 = disease of the young
More common the further from the equator you go (possible a link to Vitamin D) – explains why it is exacerbated by heat
What are the risk factors for MS?
Females
20-40
Autoimmune disease
FHx - Associated with HLA-DR2
EBV exposure in childhood
What is the pathophysiology of MS?
Type IV Hypersensitivity Rxn:
T-cell mediated – T cells activate B cells to produce auto-antibodies against Basic myelin protein of oligodendrocytes
T Lymphocytes manage to cross the BBB, they can cause a cascade of destruction to the neuronal cells in the brain by recruiting other immune cells
This results in plaques of demyelination and inflammation and therefore conduction disruption along axons
Although the myelin sheath does regenerate, the new myelin is less efficient and temperature dependent
Therefore Symptoms are exacerbated by heat
Where do the plaques of Demyelination occur in MS?
Often Perivenular (but can occur anywhere in the CNS)
Commonly at:
Optic nerves - blurred vision
Ventricles of the brain
Corpus Callosum
Brainstem and cerebellum connections
Cervical Spinal Cord
What are the features of pathological lesions in Active MS?
- Demyelination – breakdown products present
- Variable oligodendrocytes
- Hypercellular plaque edge due to infiltration of tissue with inflammatory cells
- Perivenous inflammatory infiltrate (mainly macrophages and T-lymphocytes)
- Extensive BBB disruption
- Older active plaques may have central gliosis
What are the features of pathological lesions in Inactive MS?
- Demyelination – breakdown products absent
- Variable oligodendrocytes loss
- Hypocellular plaque
- Variable inflammatory infiltrate
- Moderate to minor BBB disruption
- Plaques gliosed
What are the different Classifications of MS?
- Pattern 1 – macrophage mediated
- Pattern 2 – antibody mediated
Lots of inflammation, those patients respond to certain therapies such as plasma exchange - Pattern 3 – distal oligodendrogliopathy and apoptosis (ischaemic/toxic, virus induced)
- Pattern 4 – primary oligodendroglia degeneration (metabolic defect)
What are the types of MS Progression?
Relapse - Remitting:
The most common pattern (85% of cases)
Episodic flare-ups (may last days, weeks or months), separated by periods of remission
Secondary Progressive:
Starts with relapse remitting
Gets progressively worse w/o remission
Primary Progressive:
Symptoms get progressively worse from disease onset with no periods of remission
Progressive/relapsing:
Progressive disease from onset, with clear acute relapses, with or without full recovery, with periods between relapses characterised by continuing progression
What is Uhtohoff’s Phenomenon?
worsening of neurological symptoms in MS when body gets overheated from hot weather, exercise, saunas and hot tubs, showers
What percentage of MS patients progress from relapse remitting to secondary progressive MS?
60-75% progress within 15 years
What are the causes of MS?
Unclear cause for demyelination but:
Multiple genes
Epstein–Barr virus (EBV)
Low vitamin D
Smoking
Obesity
combination of these have an influence
What is the presentation of MS?
Variable presentation depending on region affected
Sx progress over 24 hrs and can last days-weeks and then Improve
What are the General symptoms of MS?
Charcot’s Triad:
- Dysarthria - Plaques in the brainstem
- Intention Tremor - Plaques along motor pathways
- Nystagmus - Plaques in nerves of eyes
- Spinal cord
Weakness
Paraplegia
Spasticity
Tingling
Numbness
- Optic nerves
Impaired vision
Eye pain
Medulla and pons
Dysarthria
Double vision
Vertigo
Nystagmus
- Cerebellar white matter
Dysarthria
Nystagmus
Intention tremor
Ataxia
What are the clinical signs of MS?
- Typical – LOSS NB
L - Lhermitte’s sign - electric shock runs down back and radiates to limbs
O - Optic neuritis – impaired vision and eye pain
S - Spasticity and other pyramidal signs
S - Sensory symptoms and signs
N - Nystagmus, double vision and vertigo - 6th nerve palsy
B - Bladder and sexual dysfunction
- Exacerbated by heat – showers, hot weather, saunas (Uhthoff’s phenomenon)
- Improved by cool temperatures
What are the primary investigations for MS?
Clinical Dx (using McDonald criteria) and Sx progression/remission
Contrast MRI of Brain and spinal cord:
Used to support Dx by identification of demyelinating plaques
LP w/ CSF Electrophoresis - may show oligoclonal IgG bands in CSF
Evoked Potentials - Test length of time of impulse travel
What is the McDonald Criteria?
Criteria used to diagnose MS:
- 2 or more CNS lesions disseminated in time and space
- Need to be sure it affects two parts of nervous system e.g. brain and spinal cord, optic nerve and brain
- More than one attack spaced out in time e.g. optic neuritis last year, now present with weakness in both legs
What would the results of the McDonald Criteria be to diagnose MS?
2 or more relapses
AND EITHER
Objective clinical evidence of 2 or more lesions
OR
Objective clinical evidence of one lesion WITH a reasonable history of a previous relapse
(Objective evidence’ is defined as an abnormality on neurological exam, MRI or visual evoked potential)
Who manages MS?
MDT:
including neurologists, specialist nurses, physiotherapy, occupational therapy and others.
How can acute relapses of MS be treated (Relapse-Remitting MS)?
Steroids:
IV Methylprednisolone
+ Sx treatment of Complications:
Depression - SSRIs
Neuropathic pain - Gabapentin
Exercise - maintain strength
How can Chronic MS be treated long term?
1st line (frequent relapse):
– SC beta interferon and glatiramer acetate
2nd line (disease modifying):
- IV alemtuzumab – CD52 monoclonal antibody that targets T cells
- IV natalizumab – acts against VLA-4 receptors that allow immune cells to cross the BBB and therefore reduces number of immune cells that can enter the CNS and cause damage
What are the side effects to Beta Interferon injections used to treat MS?
Injection site reactions
Flu-like symptoms
Mild intermittent lymphopenia
Mild to moderate rises in liver enzymes
Most common S/E (e.g. flu-like symptoms) tend to decrease after the first few months of treatment
What is Guillain Barre Syndrome?
Guillain-Barré syndrome (GBS) is an autoimmune, rapidly progressive demyelinating condition of the peripheral nervous system, often triggered by infection (URTI/GI)
“Equivalent to MS for the PNS”
What is the Epidemiology of Guillain Barre Syndrome?
More common in males
Peak ages 15-35 and 50-75
Most common acute polyneuropathy
What are the causes of Guillain Barre Syndrome?
Usually triggered post infection (6 weeks) and strongly associated with:
Campylobacter jejuni (most common)
CMV
EBV
What is the most common cause of Guillain Barre Syndrome?
Post C. jejuni infection
What is the most common type of Guillain Barre Syndrome?
What are the 3 classical symptoms of this type?
Acute demyelinating inflammatory polyneuropathy (ADIP) in 90% of cases
Presents with:
Progressive symmetrical weakness in limbs
Reduced or absent tendon reflexes
Reduced sensation
What is the pathophysiology of Guillain Barre Syndrome?
Molecular Mimicry:
A pathogenic antigen (e.g. Campylobacter jejuni) resembles myelin gangliosides in the peripheral nervous system
The immune system targets the antigen of pathogen and subsequently and attacks the similar antigen of the myelin sheath of sensory and motor nerves Schwann Cells
Nerve cell damage consists of damage to the Schwann cells and therefore segmental demyelination 🡪 reduction in peripheral nerve conduction 🡪 an acute polyneuropathy
This autoimmune process involves the production of anti-ganglioside antibodies (anti-GMI is positive in 25% of patients)
The demyelination causes polyneuropathy
What are the risk factors for Guillain Barre Syndrome?
History of respiratory or GI infections 1-3 weeks prior to onset
Vaccinations have been implicated e.g. flu vaccine
Post pregnancy – incidence decreases during pregnancy but increases in months after delivery
What are the symptoms of Guillain Barre syndrome?
Recent Hx of Infection (GI/URTI)
Paraesthesia and numbness
Muscle weakness
Back and limb pain
CN involvement – diplopia and dysarthria
Respiratory – affects diaphragm 🡪 death
- Autonomic features
Sweating
Raised pulse
Postural hypotension
Arrhythmias
What are the clinical signs of Guillain Barre Syndrome?
Reduced sensation in limbs
Ascending Symmetrical weakness - lower extremities first (proximal then distal)
Loss of deep tendon reflexes (hyporeflexia)
Autonomic dysfunction - Tachycardia, HTN, postural hypotension etc.
Respiratory distress - RF in 35% of patients
What are the primary investigations for Guillain Barre syndrome?
Lumbar Puncture (L4) - Raised protein + normal WCC = inflammation but no infection
Nerve conduction studies:
Conduction velocity reduced/blocked
Lung Function Tests (spirometry) - Decreased FVC
What investigations can aid to confirm the diagnosis of Guillain Barre?
Ix to exclude other causes:
TFTs - Hypothyroidism for cause of weakness
U&Es - Electrolytes for neuropathic issues
Spirometry - measure lung function
What is the management of Guillain Barre syndrone?
First line:
IV Ig (immunoglobulin) for 5 days - reduces duration and severity of paralysis
+ Plasmapheresis - to remove autoantibodies
LMWH (enoxaparin) reduce risk of venous thrombosis
What is the prognosis of Guillain Barre?
Good prognosis
85% make a full recovery
When may Ig treatment for Guillain Barre be contraindicated?
If patient is IgE deficient
May cause an allergic reaction
What are some Differential Diagnoses of Guillain Barre Syndrome?
Other causes of NM paralysis
Hypokalaemia
Polymyositis
Myasthenia gravis
Botulism
Poliomyelitis
What is Huntington’s Chorea (HD)?
A Neurodegenerative Autosomal dominant genetic condition causing chorea characterised by the lack of the main inhibitory neurotransmitter GABA
What is the penetrance of HD?
Full penetrance:
All genotypes of Huntington’s will express the phenotype
Also shows Anticipation
What are the genetics related to HD?
Huntington’s chorea is a “trinucleotide repeat disorder” that involves a genetic mutation in the Huntingtin (HTT) gene on chromosome 4.
Need >36 Triplet CAG repeats affecting HTT gene to be diagnostic of HD
What is a common feature of tri-nucleotide repeat disorders in terms of prevalence?
They Show anticipation:
where successive generations have more repeats in the gene, resulting in:
Earlier age of onset
Increased severity of disease
What is the Pathology of Huntington’s Chorea?
Repeated CAG sequence leads to translation of an expanded polyglutamine repeat sequence in the huntingtin gene
The more CAG repeats present, the earlier symptoms present
Faulty Huntingtin protein builds up in the striatum causing cell death and loss of cholinergic and GABA-nergic neurons 🡪 decreased ACH and GABA synthesis in striatum
Less GABA causes less regulation of dopamine to striatum causing increased dopamine levels resulting in excessive thalamic stimulation and subsequently increased movement (chorea)
When do symptoms of HD usually present?
Often ASx in patients under 30 yrs
Sx present between 30-50 yrs initially with a prodromal phase of mild Sx
People with HD will have more severe symptoms typically around 60+ yrs
What are the symptoms of HD?
Insidious progressive worsening:
Starts with cognitive, psychiatric and mood problems (around middle age)
Then can progress to:
Chorea (involuntary, abnormal movements)
Eye movement disorders
dysarthria
dysphagia
How is a Diagnosis of HD made?
Clinical diagnosis with FHx HD and subsequent generations showing anticipation.
Genetic testing - >36 CAG repeats on chromosome 4
MRI/CT - Shows atrophy of striatum
What is the treatment of HD?
No Tx to stop or progress HD
Provide Extensive counselling and support
Can provide Sx treatment for chorea:
Chorea:
Antipsychotics (olanzapine) - Dopamine Receptor antagonists
Benzodiazepines (diazepam)
Dopamine-depleting agents (tetrabenazine)
Depression - SSRI (sertraline)
What is the prognosis of HD?
Progressive uncurable condition
Life expectancy of 15-20 years post diagnosis
Death in HD most commonly caused by aspiration pneumonia or Suicide
What are some differential diagnoses for chorea such as in HD?
HD
Sydenham’s chorea (rheumatic fever)
SLE
Basal ganglia stroke
Wilson’s disease
What are the causes of depression?
Psychiatric:
Anxiety
Alcohol abuse
Substance misuse
Grief
Physical:
Parkinson’s
MS
Endocrine
Medication – Beta-blockers, combined OCP
CV accident (stroke)
Learning difficulties
What are the symptoms of Depression?
Low mood – loss of interest in activities they used to enjoy
Appetite and weight change
Sleep pattern changes – sleeping too much/difficult sleeping
Fatigue
Lack of concentration or making decisions
Feelings of worthlessness or excessive/inappropriate guilt
Self-harm and suicide
How can Depression be treated/managed?
Mental health team – crisis team - IAPT
CBT
Counselling
Medication
Selective Serotonin Reuptake Inhibitors e.g. fluoxetine, sertraline
Prevent the presynaptic neuron from reabsorbing serotonin so more remains in synaptic cleft and can stimulate receptors on post synaptic neuron (in pre-frontal cortex)
Tricyclic antidepressants e.g. amitriptyline and amoxapine
Act on muscarinic receptors
Information/education
What is Parkinson’s Disease (PD)?
A progressive neurodegenerative movement disorder characterised by loss of dopaminergic neurones within the substantia nigra pars compacta (SNPC) of the basal ganglia (nigrostriatal pathway).
What is the Epidemiology of PD?
The second most common neurodegenerative disorder after dementia
Prevalence increases with age (peak onset 55-65)
More common in males
What are the risk factors for PD?
Increased age
Male
FHx
What is the peak age of onset for PD?
55-65 yrs
What are the causes of PD?
Idiopathic condition but potentially related to genetics
There are secondary causes of parkinsonism:
Drugs/Toxins - CO
Wilsons disease
Infections - Encephalitis, Creutzfeldt-Jakob Disease
What are the genetic factors related to PD?
Mutation in Parkin Gene
Mutation in alpha-Synuclein gene
What is the pathogenesis of PD?
- Neurodegenerative loss of dopamine secreting cells from the pars compacta of the substantia nigra that project to the striatum
- Reduced striatal dopamine levels
- Less dopamine means the thalamus will be inhibited resulting in a decrease in movement
- symptoms of Parkinson’s
- Under the microscope you will see the presence of intracytoplasmic intrusion bodies in the remaining neurones: Lewy bodies
What are the typical Parkinsonism Symptoms?
Bradykinesia
Resting Tremor
Rigidity
What are the symptoms of PD?
Parkinsonism (bradykinesia, Resting Tremor, Rigidity)
Postural Instability
Anosmia - early sign
Constipation
Sleep disturbances
Cognitive/memory problems
Depression
What are the clinical signs of PD?
Signs are often Asymmetrical (unilateral)
Pin rolling tremor of thumb
Lead pipe arm (reduced arm swing)
Shuffling gait
Cogwheel movement
What makes up a diagnosis of PD?
Clinical Dx based on Sx and Examination and Hx
- Bradykinesia + 1 or more other Cardinal Sx
DaTSCAN - Imaging to dopaminergic terminals in Str
MRI/Head CT - may show SNpc Atrophy
What is the treatment for PD?
No cure so Sx management
- Levodopa (synthetic Dopamine) to increase levels (as dopamine cannot cross BBB)
+ Benserazide or Carbidopa - Dopa Decarboxylase inhibitors
(eg. Carledopa (Levodopa + Carbidopa)) - Dopamine Agonists - Bromocriptine
- COMT/MAO-B Inhibitors - Rasagiline (COMT) / Selegiline (MAO-B)
Surgical - Deep Brain Stimulation
What is the issue with using levodopa to treat PD?
Initially works well but soon the Px becomes resistant to it and the effects wear off.
Therefore want to only use it when Sx are bad enough to prevent early resistance.
What is an important differential diagnosis to PD?
Lewy body dementia (often associated with parkinsonism)
Parkinson Sx then Dementia = Parkinson dementia
Dementia then Parkinson Sx = Lewy body dementia w/ Parkinsonsim.
What is dementia?
A syndrome caused by neurodegeneration of various causes resulting in progressive reduction of cognition and difficulty with ADLs
What is the epidemiology of dementia?
Rare under 55 years
Prevalence rises with age
Alzheimer’s most common – more common in females
Vascular and mixed dementias are more common in males
Autosomal dominant – 10-20% of developing it
What is the commonest cause of dementia?
Alzheimer’s Disease (AD)
Accounts for 60-75% of all dementias
What is the epidemiology of AD?
Rarely affects under 65yrs
(otherwise EOAD which accounts for 3% of cases)
Affects more females than males
Prevalence significantly rises with age
What is the pathophysiology of AD?
Accumulation of Beta amyloid plaques (Ab plaques) and Tau Neurofibrillary tangles (NFT) in the cerebral cortex.
This leads to cortical scarring and brain atrophy
Additionally, damage to ACh neurons leading to poor neurotransmission
What is the APP protein?
Amyloid Precursor protein that is pathologically cleaved into Beta Amyloid plaques that accumulate in the brain (AD) and other tissues (in amyloidosis)
What are the risk factors for AD?
Increasing age
Downs Syndrome
APP gene mutation
APOE4 allele for familial AD (linked to EOAD)
What are the symptoms of AD?
Agnosia - cant recognise things
Apraxia - Cant do basic motor skills
Aphasia - Speech difficulties
Amnesia - Memory impairment
What is the progression of cognitive decline like in AD?
Steady progressive decline
What is the second most common cause of dementia?
Vascular Dementia
Accounts for roughly 20% of cases
What is Vascular Dementia?
Cognitive decline that occurs in a stepwise manner due to a Hx of cerebrovascular events.
What is the pathophysiology of Vascular dementia?
Hx of cerebrovascular events leads to infarction and loss of brain cells/damaged tissue.
Neurons cannot regenerate so the neurodegeneration is permanent.
Increased risk of secondary cerebrovascular events can lead to further brain damage and cognitive decline.
What are the symptoms of vascular dementia?
Signs of vascular pathology:
Raised BP
Hx of cerebrovascular events
Focal CNS signs
General cognitive decline in a stepwise manner
What is Lewy Body Dementia?
3rd most common form of dementia
Alpha-Synuclein and Ubiquiting aggregates accumulate in the cerebral cortex
Results in cognitive decline.
