Neuro Diseases Flashcards
What is the epidemiology of MS?
Females
Presentation between 20-40
White populations
What is the aetiology/ risk factors for MS?
Not understood Exposure to EBV in childhood Living far from equator and low vit D White populations Female
Briefly explain the pathophysiology of MS
Autoimmune mediated demyelination of olgiodendrocytes.
T cells activate B cells to produce autoantibodies against myelin. Myelin does regenerate but new myelin is less efficient and is temp dependent. Repeated demyelination leads to axonal loss and incomplete recovery= Relapsing and remitting symptoms
There is also sclerosis which further blocks conduction
What are the types of MS?
Relapsing and remitting (80%)
Secondary progressive
Primary progressive (10-15%)
What is the most common type of MS?
Relapsing and remitting
Where does demyelination normally occur in MS?
Optic nerves, around ventricles, corpus callosum, brainstem and cerebellar connections, cervical cord
How is MS treated?
Advise to live a stress free life Give Vitamin D Acute relapse= IV methyprenisolone Frequent relapse= SC interferon 1B or 1A= Antinflammatory cytokines Monoclonal antibodies= IV alemtuzumab IV natalizumab and dimethyl fumarate Symptomatic treatments= Physiotherapy, bac lofen, botox Stem cell treatments
What are the clinical features of MS?
Usually presents aged 20-40 Symptoms worsen with heat Pain in one eye upon eye movement Reduced central vision Lhermitte's sign= Tingling into limbs on flex of neck Leg weakness Dysphagia Numbness Trigeminal neuralgia Cerebellar symptoms Urinary incontinance
How is MS diagnosed?
MRI scan= 95% have periventricular lesions, white matter abnormalities
Bloods to rule out others= FBC, U&Es, HIV test, glucose, inflammatory markers
Must have 2+ attacks affecting different parts of of CNS
Lumbar puncture= IgG bands
Electrophysiology
What is the aetiology of meningitis?
- Normally= N. Meningitdes (Droplets), strep. pneumoniae, haemophilius influenza
- Pregnancy= Listeria monocytogenes
- Neonates= E. coli, group B haemolytic strep
- Viral= Enterovirus, herpes simplex virus
What are the risk factors of meningitis?
- Intrathecal drugs
- IV drug abuse
- Immunocompromised
- Elderly
- Pregnant
- Crowding
- Diabetes
- Malignancy
What is the clinical presentation of bacterial meningitis?
- Headache, fever and neck stiffness
- Sudden onset
- Papilloedema
- Malaise, rigors, photophobia, vomitting, irritability
- Positive Kernig’s and Brudzinskis signs
What is the clinical presentation of septicaemia?
Non blanching petechial (glass test) and purpuric skin rash, seizures
What is the clinical presentation of viral meningitis?
- Benign self limiting condition (4-10 days)
- Headaches for months following
What is the clinical presentation of chronic meningitis?
- Long history of vague symptoms of headache, anorexia, vomitting
- Triad (Headache, neck stiffness, fever) is often absent of late
What is the lumbar puncture result of bacterial meningitis?
- Cells= Polymorphs
- Protein= Raised
- Glucose= Low
What is the lumbar puncture result of chronic (TB) meningitis?
- Cells= Lymphocytes
- Protein= Raised
- Glucose= Low/ Normal
What is the lumbar puncture result of viral meningitis?
- Cells= Lymphocytes
- Protein= Normal
- Glucose= Normal
How is meningitis diagnosed?
- Blood cultures before lumbar
- Lumbar puncture at L4
- Blood tests= FBC, U&E, CRP
- CT of head for tumour
- Throat swabs
- Don’t perform lumbar if septicaemia is suspected
How is meningitis treated?
- Bacterial= IV Cefotaxime or IV Ceftriaxone
- IV chloramphenicol if CI with penicilins
- If immunocompromised, add IV amoxicillin to cover listeria
- Consider steroids e.g. dexamethasone to reduced cerebral oedema
- Prophylaxis for contacts
- Viral meningitis= aciclovir
What is the cause of extradural haemorrhage?
- Most commonly due to a traumatic head injury resulting in fracture of the temporal or parietal bone causing laceration of the middle meningeal artery, typically after temple trauma
What are the risk factors for extradural haemorrhage?
Usually occurs in young adults
What are the clinical features of extradural haemorrhage?
- Severe headache, nausea and vomitting, confusion and seizures, weakness and brisk reflexes
- Rapid rise in ICP
- Ipsilateral pupil dilates, coma, bilateral limb weakness, deep and irregular breathing
- Coning
- Death due to respiratory arrest
How is extradural haemorrhage treated?
- ABCDE emergency management= asses and stabilise patient
- Give IV mannitol if increased ICP
- Refer to neurosurgery
- Maintain airway
How is extradural haemorrhage diagnosed?
- CT of head (gold standard)= shows hyperdense haematoma that is biconcave/lemon shaped
- Skull x ray= May be normal or show fracture lines crossing the course of the middle meningeal artery
What is the commonest primary headache?
Tension headache
What are the causes of tension headache?
- Stress
- Sleep deprivation
- Bad posture
- Hunger
- Eye strain
- Anxiety
- Noise
What is the clinical presentation of tension headache?
- Usually has 1 of the following= Bilateral, pressing/tight non-pulsatile, mild/moderate intensity, scalp muscle tenderness
- Band-like tight sensation
- Pressure behind eyes
- Can last 30mins-7days
- Episodic (<15days/month) or chronic (>15days/month)
How is tension headache diagnosed?
Clinical diagnosis from history
How is tension headache treated?
- Lifestyle advice
- Stress relief e.g. massage, accupuncture
- Symptomatic treatment= aspirin, paracetamol, NSAIDS (but don’t use too much, to prevent a medication overuse headache)
What is the epidemiology of cluster headache?
- Rarer than migraine
- More common in males
- Affects adults= 20-40yrs
- Commoner in smokers
What are the risk factors for cluster headache?
- Smoker
- Male
- Autosomal dominant gene has a role
What are the clinical features of a cluster headache?
- Rapid onset of excrutiating pain around one eye, temple or forehead
- Ipsilateral cranial autonomic features= Facial flushing, eye may become watery and bloodshot, blocked nose, miosis +/- ptosis
- Rises to crescendo over minutes and lasts 15-160 mins, once or twice a day, usually at same time
- Episodic clusters last 4-12 weeks and are followed by pain free periods of months or even yrs between clusters
How are cluster headaches diagnosed?
Clinical diagnosis= At least 5 headache attacks fulfilling the above criteria
How are cluster headaches treated?
- Acute attack: analgesics are unhelpful. Give oxygen for 15 mins
- Triptan = serotonin receptor antagonists- reduces vascular inflammation
- Calcium channel blocker is first line prevention
- Avoid alcohol during cluster period
- Corticosteroids may help during cluster
What is the epidemiology of trigeminal neuralgia?
- Peak incidence between 50-60yrs
- More common in females
- Prevalence increases with age
- May be due to genetic predisposition
What are the risk factors for trigeminal neuralgia?
- Hypertension
- Triggers= Washing affected area, shaving, eating, talking, dental work
Briefly explain the pathophysiology of trigeminal neuralgia
Compression of the trigeminal nerve by a loop of vein or artery resulting in local demyelination, or due to local pathology (tumours, infarction, MS) resulting in erratic pain signalling
What are the clinical features of trigeminal neuralgia?
- Almost always unilateral
- At least three attacks of unilateral facial pain
- Occurs in 1 or more distributions of the trigeminal nerve, with no radiation beyond the trigeminal distribution
- Pain has at least 3 of the following- reoccurring, severe intensity, shooting stabbing or electric pain, precipitated by innocuous stimuli
How is trigeminal neuralgia treated?
- Typical analgesics and opioids do not work
- Anticonvulsants can suppress attacks
- Other options include phenytoin, gabepentin, lamotrigine
- May spontaneously remit after 6-12 months
- Surgery may be necessary; microvascular decompression, gamma knife surgery
How is trigeminal neuralgia diagnosed?
- At least 3 attacks with unilateral facial pain
- MRI to exclude secondary causes
What is the epidemiology of Herpes Zoster infection?
- 90% of 16 yr olds have been exposed (chickenpox)
- Shingles can affect all ages but is seen as a disease of the elderly
What are the risk factors for shingles?
Increasing age
Immunocompromised
Briefly explain the pathophysiology of shingles
- Latent varicella zoster virus is reactivated in the dorsal root ganglia and travels down the affected nerve via the sensory root in dermatomal distribution
- Results in perineural and intrameural inflammation
- Most commonly occurs in thoracic nerve, and then the ophthalmic division of the trigeminal nerve
What are the clinical features of shingles?
- Pain and paraesthesia in dermatomal distribution
- Malaise, myalgia, headache and fever
- Can be over a week before eruption occurs
- Rash- consists of papules and vesicles, causes neuritic pain, crust formation and drying occurs.
How is shingles diagnosed?
- Clinical diagnosis
- Eruption of rash is virtually diagnostic
How is shingles treated?
- Oral antiviral therapy begun with 72 hrs of rash onset (Oral aciclovir, oral valiciclovir, oral famcliclovir )
- Topical antibiotic treatment
- Analgesia
What are some possible complications of shingles?
- Opthalmic branch of trigeminal nerve (will affect site)
- Post herpetic neuralgia= burning, intractable pain lasting for over four months, responds poorly to analgesics
Briefly explain the pathophysiology of encephalitis?
- Disease which mostly affects frontal and temporal lobes resulting in decreased consciousness, confusion and focal signs
What is the aetiology of encephalitis?
- Mainly viral= Herpes simplex, EBV, cytomegalovirus, varicella zoster, HIV
- Non viral= Bacterial meningitis, malaria, TB
What are the clinical features of encephalitis?
- Whole brain infected= Problems in higher functioning and consciousness
- Triad= fever, headache, altered mental status
- Begins with features of viral infection= triad, myalgia, fatigue, nausea
- Progresses to: personality and behavioral changes, coma, drowsiness, seizures
- Focal neurological deficit=hemiparesis and dysphagia
- Raised ICP and midline shift
How is encephalitis diagnosed?
- MRI: shows area of inflammation and swelling, generally in the temporal lobes in HSV encephalitis. May be midline shifting due to raised ICP
- Electroencephalography (EEG): shows periodic sharp and slow wave complexes
- Blood and CSF serology
- Lumbar puncture shows increased lymphocytes, viral detection by CSF PCR
How is encephalitis treated?
- If viral immediate treatment with anti-viral e.g. IV aciclovir- even before the investigation results are available
- Early treatment can reduce mortality and long neuro damage
- Anti seizure medication e.g. primadone
What is the epidemiology of subdural haemorrhage?
- Most common in patients with small brain (Babies, elderly and alcoholics)
- Majority of SDHs are from trauma, but can be minor/long ago
- Chronic/ apparently spontaneous SDH is common in elderly
What are the causes of subdural haemorrhage?
- Trauma causing bleeding from bridging veins between the cortex and venous sinuses, causing a haematoma between dura and arachnoid mata
What are the clinical features of subdural haemorrhage?
- Interval between injury and symptoms can be days-months
- Fluctuating levels of consciousness with insidious physical or intellectual slowing
- Personality change
- Unsteadyness
- Signs of raised intercranial pressure= headache, vomitting, nausea, seizure, raised BP
- Focal neurology (hemiparesis, sensory loss)
- Stupor, coma and coning
How is a subdural haemorrhage diagnosed?
CT of head to show diffuse spreading, hyperdense, crescent shaped collection of blood over one hemisphere
How is subdural haemorrhage treated?
- Stabilise patient
- Refer to neurosurgeons: Irrigation/ evacuation via burr twist drill and burr hole craniotomy
- Address cause of trauma
- IV mannitol to reduce ICP
What are the commonest neoplasms to metastasise to the CNS?
- Non-small cell ling
- Small cell lung
- Breast
- Melanoma
- Renal cell
- GI
What are the risk factors for primary brain tumours?
- More common in affluent groups
- Ionising radiation
- Vinyl chloride
- Immunosuppression
- Family history= genetics
What are the most common primary brain tumours?
- Gliomas= Astrocytomas or oligodendromas
- Meningiomas
What is the most common primary brain tumour?
Astrocytoma
What are the clinical features of brain tumours?
- Progressive focal neurological deficit
- Raised ICP= Headaches, drowsiness, vomitting
- Epilepsy= Focal or generalised
- General cancer symptoms= Weight loss, malaise, anaemia
- Papilloedema
How are brain tumours diagnosed?
- CT or MRI to determine size and location of lesions
- Blood tests
- Biopsy via skull Burr Hole
- Positron Emission Tomography
How are brain tumours treated ?
- Surgery if less than 75
- Radiotherapy
- Medical treatment of symptoms
- Palliative care
What are the two types of stroke?
Ischaemic and haemorrhagic
What is the epidemiology of ischaemic stroke?
- Accounts for 80% of all strokes
What causes ischaemic stroke?
- Small vessel occlusion/ thrombosis in situ
- Cardiac emboli from AF, MI or infective endocarditis
- Large artery stenosis
- Artherothromboembolism
- Hypoperfusion, vasculitis, hyperviscocity
Briefly explain the pathophysiology of ischaemic stroke
Arterial disease and atherosclerosis causes thrombosis to occur which blocks a vessel leading to ischaemia
What are the clinical features of ischaemic stroke?
- Cerebral hemisphere: signs contralateral to the affected side, hemiplegia, hemisensory loss, upper motor neurone facial weakness and hemianopia
- Brainstem: Complex, depends on location
- Multi infarct: Multiple steps progressing to dementia
What are the causes of CNS bleeds?
- Trauma
- Aneurysm rupture
- Anticoagulation
- Thrombolysis
- Carotid artery dissection
- Subarachnoid haemorrhage
What is the epidemiology of haemorrhagic stroke?
- Accounts for 17% of strokes
What are the clinical features of haemorrhagic stroke?
- Severe headache= like being hit in the head
- Nausea/ vomitting
- Sudden loss of conscious
- Classic stroke symptoms= signs contralateral to affected. Hemiplegia, hemisensory loss, upper motor neurone facial weakness and hemianopia
Briefly explain the pathophysiology of haemorrhagic stroke
- Hypertension resulting in micro aneurysm rupture
- Cerebral amyloid angiopathy: Deposition of amyloid B on the walls of small and medium sized arteries in normotensive patients
- Space occupying lesion e.g. tumour
- Young adults: Carotid/vetebral artery dissection
What are the risk factors for haemorrhagic stroke?
Hypertension, excess alcohol, smoking and age
How is ischaemic stroke treated?
Aspirin, IV alteplase in at least 4.5 hours (thrombolytic; IV tissue plasminogen activator), antiplatelet (aspirin -> lifelong clopidogrel), maintain glucose, NBM
How is ischaemic stroke treated?
Stop anticoagulants.
What is the epidemiology of cauda equina syndrome?
- Rare, occuring mainly in adults but can occur at any age
- Occurs in around 2% of herniated discs
What is the aetiology of cauda equina syndrome?
- Herniation of lumbar disc= most commonly at L4/5 or L5/S1
- Tumours/ metastasis
- Trauma
- Infection
- Spondylolisthesis
- Post op haematoma
What are the clinical features of cauda equina syndrome?
- Sciatica= pain, numbness and a tingling sensation that radiates from lower back and travels down one leg to the foot
- Saddle anaesthesia
- Bladder/ bowel dysfunction
- Erectile dysfunction
- Variable leg weakness that is flaccid and areflexic (LMN signs)