5- Neurology (Emergencies: Meningitis, Encephalitis, Spinal cord compression)) Flashcards
Meningitis background
- Inflammation of the meninges
- Usually due to bacterial (more common) or viral (less serious) infection
cause of meningitis
- Neisseria meningitidis- ‘meningococcus’- gram negative diplococcus bacteria
->11-17 yo - Streptococcus pneumoniae – ‘pneumococcus’
-> All other ages - Group B strep
-> Neonates
typical presentation of meningitis
o Fever
o Neck stiffness
o Vomiting
o Headache
o Photophobia
o Altered consciousness/ seizure
presentation of meningococcal septicaemia
non-blanching rash
presentation of meningitis in babies
Non specific: hypotonia, poor feeding, lethargy, hypothermia and bulging fontanelle
special tests for meningitis
o Kernig’s test
o Brudzinski’s
investigations for meningitis
- Bloods
o Meningococcal ~PCR - Lumbar puncture in all children
o <1month presenting with fever
o 1 to 3 months with fever and are unwell
o under 1yo with unexplained fever and other serious illness
lumbar puncture procedure
L3-L4
(spinal cord ends at L1-2)
samples are send for bacterial culture, viral PCR< cell count, protein and glucose
(blood glucose should be sent at the same time to compare to CSF)
bacterial vs viral CSF findings
meningococcal infections
- Meningococcal septicaemia
- Meingococcal meningitis
Meningococcal septicaemia
refers to the meningococcus bacterial infection in the bloodstream. Meningococcal refers to the bacteria and septicaemia refers to infection in the blood stream. Meningococcal septicaemia is the cause of the classic “non-blanching rash” that everybody worries about. This rash indicates the infection has caused disseminated intravascular coagulopathy (DIC) and subcutaneous haemorrhages.
Meningococcal meningitis
is when the bacteria is infecting the meninges and the cerebrospinal fluid around the brain and spinal cord.
viral meningitis causes
- Herpes simplex virus (HSV)
- Enterovirus
- Varicella zoster virus (VZV).
Management
Viral meningitis
tends to be milder than bacterial and often only requires supportive treatment.
- Aciclovir can be used to treat suspected or confirmed HSV or VZV infection.
management of bacterial meningits in the community
o Urgent stat injection (IM or IV) benzylpenicillin prior to transfer to hospital
management of bacterial meningits in the hospital
- Lumbar puncture prior to antibiotics (unless acutely deteriorating)
- Antibiotics
- Steroids if bacterial -> reduce severity of hearing loss and neurological damage
o Dexamethasone 4x daily for 4 days
antibiotics used in bacterial meningitis
Under 3 months – cefotaxime plus amoxicillin (the amoxicillin is to cover listeria contracted during pregnancy)
Above 3 months – ceftriaxone
o +- vancomycin if risk of penicillin resistant pneumococcal infection e.g. foreign travel or prolonged antibiotic exposure
Post exposure prophylaxis (meningococcal infection)
- Highest risk for people that have had close prolonged contact within 7 days to the onset of the illness
- Risk decreases 7 days after exposure (if no symptoms have developed 7 days after exposure they are unlikely to develop illness)
- Management: single dose of ciprofloxacin – give stat
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
Encephalitis
Background
- Inflammation of the brain
Can be
- Infective
–> Viral – most common
- Bacterial and fungal rarer
–>Non- infective
–> Autoimmune – antibodies against brain
viral causes of encephalitis
- Herpes simplex virus (HSV)
o HSV-1 most common in children (cold sore)
o HSV-2 – neonates (genital herpes contracted during birth) - Varicella zoster – chickenpox
- Cytomegalovirus – immunodeficiency
- Epstein barr virus (infectious mononucleosis)
- Enterovirus
- Adenovirus
- Influenza virus
- Polio
- MMR
TAKE EXTENSIVE VACCINE HISTORY
Bacterial causes of encephalitis
o Mycoplasma
o Meningococcal
o Pneumococcal
o listeria
fungal causes of encephalitis
o Cryptococcus
o Candia
parasitic cause of encephalitis
o Malaria
o Toxoplasma
Presentation encephalitis
- Altered consciousness
- Altered cognition
- Unusual behaviour
- Acute onset of focal neurological symptoms
- Acute onset of focal seizures
- Fever
investigations for encephalitis
- Lumbar puncture – viral PCR testing
- CT scan if lumbar puncture contraindicated
- MRI scan after LP to visualise brain
- Throat and vesicle swabs
- HIV testing
- Swabs
contraindication for LP
o GCS below 9
o Haemodynamically unstable
o Active seizures
o Post-ictal
Management of viral encephalitis
- IV acyclovir ( not oral) - HSV and VZV
- IV ganciclovir- CMV
- Repeat LP prior to stopping antivirals
- Supportive and rehab
if LP suggestes bacterial could give ceftriazone
complications of encephalitis
- Lasting fatigue and prolonged recovery
- Change in personality or mood
- Changes to memory and cognition
- Learning disability
- Headaches
- Chronic pain
- Movement disorders
- Sensory disturbance
- Seizures
- Hormonal imbalance
Spinal cord compression
Background
- Surgical emergency
- Delays in management can result in irreversible loss of function
- Most common prolapse L4/5 or L5/S1 intervertebral disc most common
Cauda equina
Compression of nerve roots caudal to the termination of the cord resulting in characteristic symptoms
Causes of spinal cord compression
- Trauma
- Prolapsed intervertebral dics
- Atlantoaxial subluxation (RA)
- Infection e.g. TB infiltrating spinal cord
- Bony metastases
o Breast
o Lung
o Kidney
o Thyroid
o prostate
Presentation
Dependent on cord level and extent of lesion
- Above T1- tetraplegia (quadriplegia)
- Below T1- paraplegia (paralysis of the lower limbs)
- Cauda equina syndrome
Characteristics
- Sudden onset and evolve over hours and days
Red flags for spinal cord compression
- Weakness
- Paraesthesia
- Ataxia
- Urinary retention
- UMN sign (e.g. clonus, hyperreflexia)
Cauda equina syndrome
Background
- Surgical emergency
- Where the nerve roots of the cauda equina are compressed
pathophysiology of cauda equina syndrome
Pathophysiology
- The cauda equina is a collection of nerve roots that travel through the spinal canal after the spinal cord terminates around L2/L3
- Spinal cord tapers down at the end in a section called the conus medullaris
- The nerve roots exit either side of the spinal column at their vertebral level (l3, L4, L5,S1, S2,S3,S4,S5,Co)
- The nerves of the cauda equina supply
The nerves of the cauda equina supply:
- Sensation to the lower limbs, perineum, bladder and rectum
- Motor innervation to the lower limbs and the anal and urethral sphincters
- Parasympathetic innervation of the bladder and rectum
causes of cauda equina
- Herniated disc (most common cause)- L4/5
- Tumours, particularly metastasis (think MSCC)
o Thyroid breast lung renal prostate - Spondylolisthesis (anterior displacement of a vertebra out of line with the one below)
- Abscess (infection)
- Trauma
- Iatrogenic- haematoma secondary to spinal anaesthesia
presentation of cauda equina
Lower motor neurone signs i.e. reduced tone and reflexes
Red flags
- Saddle anaesthesia (loss of sensation in the perineum – around the genitals and anus)
- Loss of sensation in the bladder and rectum (not knowing when they are full)
- Urinary retention or incontinence
- Faecal incontinence
- Bilateral sciatica
- Bilateral or severe motor weakness in the legs
- Reduced anal tone on PR examination
classification of cauda equina syndrome
investigations for cauda equina
- PR examination for anal tone
- Emergency Lumbar-sacral spine MRI – gold standard
cauda equina mangement
Once confirmed by MRI emergency referral to spinal team. Emergency decompression surgery to prevent permanent neurological dysfunction. Within 48 hours
- Immediate hospital admission
- Emergency MRI scan to confirm or exclude cauda equina syndrome
- Neurosurgical input to consider lumbar decompression surgery
If CE due to malignancy:
radiotherapy and/or chemotherapy
prognosis and complications of CE
Prognosis
- Even with prompt surgery, some patients may still not regain full function
Complications
- Left with bladder, bowel or sexual dysfunction
- Leg weakness and sensory impairment
Metastatic spinal cord compression
Background
MSCC vs Cauda Equina
- When metastatic lesion compresses the spinal cord (before end of the spinal cord and the start of the cauda equina) – i.e. not the cauda equina
- Diff to cauda equina which refers specifically to compression of the CE
- UMN signs rather than the LMN seen in CE
Presentation of MSCC
Similar to CES
- Back pain
- Motor and sensory signs and symptoms
- Key feature: back pain worse on coughing or straining
Upper motor neurone signs
- Increased tone
- Brisk reflexes
- Upping plantar responses
management of MSCC
Oncological emergency
Treatments will depend on individual factors. They may include:
- High dose dexamethasone (to reduce swelling in the tumour and relieve compression)
- Analgesia
- Surgery
- Radiotherapy
- Chemotherapy
