Elective Neurosurgery Flashcards
Typical site of primary intracerebral haemorrhage
Basal ganglia
Cause of primary intracerebral haemorrhage
Rupture of microaneurysms of Charcot-Bouchard of the perforating arteries supplying the basal ganglia
List the risk factors associated with subarachnoid aneurysms
- HTN
- Smoking
- Cocaine
- Polycystic kidney disease
- Marfans
- Ehlers-Danlos
- Neurofibromatosis type 1
What is associated with mycotic subarachnoid aneurysms
Infective endocarditis
List the complications of SAH
- Rebleeding - 3% in first 24 hours
- Hyponatraemia
- Vasospasm
- Hydrocephalus
- Seizures
- Cardiac abnormalities
What is the aim of surgery in SAH
Prevent rebleeding
How is hyponatraemia secondary to SAH managed
Triple ‘H’ therapy:
- Hypervolaemia (3L saline per day)
- Hypertension
- Haemodilution
List the risk factors for chronic subdural haematoma
- Age
- Alcohol
- Dementia
How are chronic subdural haematomas managed
Burr hole drainage (posterior frontal and posterior parietal)
What is the most common brain tumour
Cerebral metastases
What is the most common primary brain tumour
Glioblastoma multiforme (Glioma)
What is the most common childhood brain tumour
Astrocytoma (Glioma)
Where do cerebral metastases typically seed
At the interface between grey and white matter
List the common origins of cerebral metastases
- Lung
- Bowel
- Breast
- Renal
- Melanoma
If no primary tumour is identified by non-invasive means, how should you proceed
- Stereotactic brain biopsy
- Excision biopsy
List the brain tumours of glial cell origin (gliomas)
- Astrocytoma
- Oligodendroglioma
- Ependymoma
Describe the macroscopic appearance of Glioblastoma multiforme
- Grey-ish ill-defined mass
- Areas of necrosis and haemorrhage
List the diagnostic histological features of Glioblastoma multiforme
- Vascular proliferation and thrombosis
- Necrosis
What WHO grade is Glioblastoma multiforme
4
What WHO grade is anaplastic astrocytoma
3
Why are both glioblastoma multiforme and anaplastic astrocytoma non-resectable
Due to tumour cell migration to some distance from the original lesion
Describe the macroscopic appearance of anaplastic astrocytoma
White ill-defined mass, sometimes expanding into the gyrus
From where do meningiomas arise
Arachnoid cap cells
With regards to position relative to the tentorium cerebelli, what is the difference between paediatric and adult CNS tumours
- Paediatric = most infratentorial
- Adult = most supratentorial
What WHO grade are meningiomas
1
Describe the macroscopic appearance of meningiomas
- Rubbery, round, lobulated mass
- Firmly attached to the dura
What are the indications for stereotactic radiotherapy in CNS lesions
- AVM
- Vestibular schwannoma
- Metastasis
When is de-bulking surgery indicated in CNS tumours
For young patients <65 with GBM and AA:
- Decrease mass effect for symptom relief
- Reduce ICP
- Remove lesion causing motor symptoms
How are pituitary tumours divided
- Functional (secrete hormones)
- Non-functional
OR
- Microadenomas <10mm
- Macroadenomas >10mm
List the indications for surgery in pituitary tumours
- Non-functional tumours with mass effect
- Cushing’s disease
- Acromegaly
- Acute visual deterioration
- Pituitary apoplexy (infarction/haemorrhage of the gland)
How are prolactinomas managed
Most shrink with dopamine agonists
What is the typical surgical approach to pituitary tumours
Trans-sphenoidal
How does pituitary apoplexy present (bleeding/infarction)
- Sudden-onset headache
- Sometimes visual disturbance
- Deteriorating conscious level
- Panhypopituitarism with addisonian crisis
How is SIADH managed
- Fluid restriction <1L/day
- Monitor sodium
How is hydrocephalus categorised
- Communicating
2. Non-communicating (obstructive)
Describe communicating hydrocephalus
- CSF resorption at the arachnoid granulations is arrested or slowed e.g. secondary to SAH
- All CSF spaces are increased in volume
Describe non-communicating hydrocephalus
Block to CSF flow proximal to the arachnoid granulations
How do you determine the difference between communicating and non-communicating hydrocephalus
CT/MRI
Why is it important to distinguish the difference between communicating and non-communicating hydrocephalus
- LP is life-saving in communicating hydrocephalus
- LP can cause coning in non-communicating hydrocephalus
Describe normal-pressure hydrocephalus
Clinical triad of:
- Dementia
- Gait dyspraxia
- Incontinence
How is normal-pressure hydrocephalus managed
Ventriculo-peritoneal shunt
Describe ventriculo-peritoneal shunts
- Ventricular catheter inserted into occipital horn of the lateral ventricle via burr hole
- Peritoneal catheter is tunnelled under the skin to insert into the peritoneal cavity at the costal margin
What bacteria complicate ventriculo-peritoneal shunts
Staphylococcus epidermiidis and staphylococcus aureus
How may non-communicating hydrocephalus be managed
Third ventriculostomy
What is the main pathogen in cerebral abscesses
Streptococci mainly
How may cerebral abscesses present
- Symptoms of raised ICP
- Seizure
- Focal neurology
From what sites does haematogenous spread cause cerebral abscesses
- Bronchiectasis
- Bacterial endocarditis
- Dental abscess and caries
From where does local spread cause cerebral abscesses
- Middle-ear (esp. cholesteatoma)
- Frontal and sphenoid sinusitis
- Skull base bone erosion
How are cerebral abscesses managed
- Needle drainage
- Antibiotics
From where does subdural empyema develop from
Spread from paranasal sinuses
How is subdural empyema managed
Surgical drainage via burr hole or craniotomy
