Neurology - part 2 Flashcards
What is meningitis?
Infection of the meninges
What is the difference between viral vs bacterial meningitis in terms of severity and frequency?
- Viral = more common, less severe
- Bacterial = less common, more severe
What are some risk factors for meningitis (4)?
- Immunocompromised
- Neonate
- Non-vaccinated
- University student
What are the most common viral causes of meningitis? (4)
- HSV (-2)
- VZV
- Enteroviruses (e.g. coxackie)
- Measles/ mumps
What are the most common bacterial causes of meningitis in 0-3 months (3)?
- GBS = mc
- Listeria monocytongenes
- E. coli
What are the most common causes of meningitis in 3 month - 6 year olds (3)?
- N. meningitidis
- S. pneumoniae
- H. influenziae (less common due to vaccinations)
What are the two most common causes of meningitis in 6 years - 60 years?
- N. meningitidis
- S. pneumoniae
What are the three most common causes in over 60s?
- N. meningitidis
- S. pneumoniae
- Listeria monocytogenes
What types of meningitis are immunocompromised at risk of (2)?
- Listeria monocytogenes
- Cyptococcus (fungal)
What type of bacteria are S. pneumoniae and GBS?
+ve coccus in chains
What type of bacteria is N. meningitidis?
-ve diplococcus
What type of bacteria is HIB?
-ve coccobacillus
What type of bacteria is listeria?
+ve bacillus
What are the signs/ symptoms of meningitis (7)?
- Meningism - headache, photophobia, neck stiffness
- N+V
- Fever
- Drowsiness
- Kernig
- Brudzinski
- Non-blanching purpuric rash
What is Kernig sign?
Flexing hip, then extending knee = PAIN
What is Brudzinski sign?
Flexing neck –> involuntary flexion of hips
How is meningitis investigated (2)?
- Bloods + cultures
- Lumbar puncture
CT not usually indicated unless signs of raised ICP
What would contraindicate/ delay a LP (3)?
- Sepsis/ meningococcal rash
- Severe illness
- Raised ICP
What are some signs of raised ICP (4)?
- Pappiloedema
- Seizures
- Focal neurological signs
- GCS < 12
What are the results of LP for bacteria vs viral vs fungal/TB in terms of appearance?
- Bacterial = cloudy
- Viral = clear
- Fungal/ TB = cloudy
What are the results of LP for bacteria vs viral vs fungal/TB in terms of glucose?
- Bacterial = low
- Viral = normal
- Fungal/ TB = low
What are the results of LP for bacteria vs viral vs fungal/TB in terms of protein?
- Bacterial = high
- Viral = normal
- Fungal/TB = high
What are the results of LP for bacteria vs viral vs fungal/TB in terms of WCC?
- Bacteria = neutrophils
- Viral = lymphocytes
- Fungal/TB = lymphocytes
What are the results of LP for bacteria vs viral vs fungal/TB in terms of opening pressure?
- Bacterial = raised
- Viral = normal
- Fungal/TB = normal or raised
How is meningitis treated?
- Under 3 months = IV cefotaxime + amoxicillin (for listeria)
- Over 3 months = ceftriaxone (or cefotaxime) + dexamethasone (+ amoxicillin if over 50)
When should dexamethasone not be given for meningitis (2)?
- NBP rash/ septic shock
- Under 3 months
What should be given if meningitis is suspected in GP?
IM ben pen
What should be given to close contacts of those with meningitis?
- Ciprofloxacin + vaccine
- Rifampicin
Why is cefotaxime given in place of ceftriaxone in neonates?
Ceftriaxone can displace bilirubin causing kernicterus
What are some complications of meningitis (4)?
- Sensorineural hearing loss = mc
- Seizures
- Focal neurological deficits
- Waterhouse-friderichsen syndrome
What is Waterhouse-friderichsen syndrome?
Adrenal haemorrhage (due to meningococcal septicaemia) –> adrenal insufficiency –> shock
What is encephalitis?
Parenchymal
What is the cause of encephalitis (7)?
- HSV-1 - (95%)
- TB
- Lymes
- Meningitis
- CMV
- VZV
- Toxoplasmosis
What is another non-infective cause of encephalitis?
Autoimmune encephalitis
What antibodies are usually present in the CSF and blood of those with autoimmune encephalitis?
Anti NMDA-R antibodies
What are the signs/ symptoms of encephalitis (5)?
- Seizures
- Focal neurological deficit
- Reduced GCS + confusion
- Fever
- Headache
How is encephalitis investigated (3)?
- LP
- CT/ MRI
- EEG
How should CSF be analysed in those with suspected encephalitis?
PCR - for HSV, VZV, etc
What might an EEG show in those with encephalitis?
Periodic 2 Hz firing
How is encephalitis treated?
IV Aciclovir
What is a brain abscess?
Intracranial collection of pus
What are some risk factors for brain abscesses (4)?
- Immunocompromised (HIV, T2DM)
- Congenital heart disease + endocarditis
- Neurosurgery
- Local infection (e.g. ear, mastoiditis)
When are brain abscesses most common in life?
30-40 years old
What organisms most commonly cause brain abscesses (4)?
- Strep intermedius
- Staph aureus
- Strep pneumoniae
- TB (in immunocompromised)
also fungal, parasitic infections (toxoplasmosis)
What are the signs/ symptoms of a brain abscess (3)?
- Fever
- Headache
- Focal neurological sign
How would a spinal abscess present (3)?
- Lower back pain
- Fever
- Neurological signs (below lesion)
most have T2DM
How is a brain abscess diagnosed?
CT with contrast
What feature would a brain abscess CT show?
Ring enhancing lesion
How is brain abscess managed (2)?
- Surgical debridement
- IV Abx
What antibiotics are used for a brain abscess (3)?
- Ceftriaxone (broad spectrum -ve/ some +ve)
- Metronidazole (anaerobes)
- Vancomycin (if from trauma/ neurosurgery)
What constitutes brain death (3)?
- GCS 3 (comatose)
- Brainstem signs
- Apnoea > 5 min
What are 2 postures that may be held in patients who are comatosed?
- Decorticate
- Decerebrate
What is the decorticate position?
Fore-arms flexed to chest - lesion in the cortex
good prognosis
What is the decerebrate position?
Forearm extended, internally rotated and wrist flexed - lesion at brain stem
poor prognosis
What does it suggest if a decorticate position turns into a decerebrate position?
Tonsillar herniation/ coning
What is Gillian barre syndrome?
Immune mediated demyelination of the nerves in the PNS (Schwann cells)
What usually precedes guillian barre syndrome?
Gastroenteritis
or URTI
What organism commonly causes guillian barre?
Campylobacter jejuni
What is the pathophysiology of guillian barre?
Antibodies produced against campylobacter attack the Schwann cells/ axons in the PNS
What is it known as when antibodies produced against a pathogen attack the body?
Molecular mimicry
What are the signs/ symptoms of guillian barre (5)?
- Ascending symmetrical weakness
- Reduced reflexes
- Sensory loss
- Neuropathic pain (back/leg)
- Reduced FVC
How is guillian barre investigated (3)?
- Nerve conduction studies
- Lumbar puncture
- Serology
What would nerve conduction studies show in guillian barre?
Reduced nerve conduction speed
What would LP show in guillian barre (2)?
- Raised protein
- Normal WCC
What is sometimes positive on serology of those with guillian barre?
Anti GM1
How is guillian barre managed (2)?
- IVIg
- Plasmapheresis
for 5 days
What is important to monitor in those with guillian barre?
FVC
What is miller fisher syndrome?
Variant of guillian barre, but with descending weakness, starting with the eyes instead of ascending weakness
What are the most common types of brain tumours?
Secondary metastases
Where do brain mets often come from?
- Breast
- Kidney
- Melanoma
- Lungs = MC
- Colorectal
What are the common types of brain tumours (6)?
- Astrocytoma = mc
- Meningiomas
- Pituitary adenomas
- Craniopharyngiomas
- Vestibular schwannoma
- Pinealoma
What are the 3 types of gliomas?
- Astrocytomas = mc
- Oligodendrogliomas
- Ependymomas
arise from glial cell (protect and support neurones)
What is the most aggressive astrocytoma?
Glioblastoma multiforme (grade 4)
What is a craniopharyngioma?
Slow growing tumour near the pituitary gland
What can a pinealoma cause?
Non communicating hydrocephalus
What are some signs/ symptoms of a brain tumour (5)?
- Headache
- Seizures
- Focal neuro symptoms
- N+V
- Raised ICP Sx
What are some red flags for brain tumour headaches (4)?
- Morning headache
- Headache worsened by valsalvar
- Vomiting with headache
- Constant headache
What are some symptoms of raised ICP (5)?
- Pappilloedema
- N+V
- Seizures
- CN3,6 palsy
- Visual field defects
How are brain tumours investigated?
MRI
How does a glioblastoma multiforme appear on a MRI?
Ring enhancing lesion (with contrast)
How are brain tumours treated (3)?
- Dexamethasone
- Surgery
- Chemo/ radiotherapy
What is a neuropathy?
Any condition affecting the nerves outside of the CNS
What are the patterns of neuropathy (3)?
- Mononeuropathy (1 nerve affected)
- Mononeuritis multiplex (multiple single nerves affected)
- Polyneuropathy (symmetrical nerves affected, ‘glove + stocking’ distribution)
What are some causes of mononeuritis multiplex (4)?
- Vasculitis (e.g. polyarteritis nodosa)
- Rheumatoid arthritis
- SLE
- Diabetes
What are some causes of polyneuropathy?
- Alcohol
- B12 deficiency
- Chemotherapy
- Diabetes
- Every vasculitis
- Guillian barre
What is a radiculopathy?
The compression of the nerve at the ROOT
What is myelopathy?
Compression of spinal cord
What are some specific mononeuropathies to be aware of (5)?
- Median nerve (carpal tunnel syndrome)
- Ulnar nerve
- Radial nerve
- L5 radiculopathy
- Common perineal nerve
What are the nerve roots of the median nerve?
C6-T1
What are some causes of carpal tunnel syndrome (4)?
- RA
- Acromegaly
- Hypothyroid
- Repetitive overuse
What are the signs/ symptoms of carpal tunnel syndrome (2)?
- Parasthesia
- Thenar muscle waisting
What two specific tests can indicate carpal tunnel syndrome?
- Tinels
- Phalens
What would a nerve conduction study show in someone with carpal tunnel?
Decreased velocity/ amplitude
How is carpal tunnel treated (2)?
- 1st = splint
- Gold = surgery