Neurosurgery Flashcards
Definition of extradural haematoma
Bleeding into the space between the dura mater and skull
Causes of extradural haematoma
Acceleration-deceleration injury
Blow to the side of the head
Often temporal region due to bleeding in the middle meningeal artery
Symptoms and signs of extradural haematoma
Brief post-trauma LOC follwed by lucidity, reduced consciousness, hemiparesis and ipsilateral pupil dilation Headache Vomiting Seizure Hemi hyperreflexia Abnormal babinski (hemi) Increased CSF opening pressure
Diagnosis of extradural haematoma
CT scan- typical lemon appearance
May cross midline unlike subdural
Frequently mass effect
Management of EDH
Less than 1cm and minimal symptoms without herniation- admit, observe, several days of steroids
Serial CT scans to follow up
If not- evacuation
Definition of subdural haematoma
Bleeding into the most external meningeal layer
Causes of SDH
Acute:
- Traumatic secondary to parenchymal laceration or acceleration deceleration
- Anticoagulant therapy
Chronic
- Past bleeds that are smaller but continue
Symptoms of SDH
Headache Vertigo Amnesia Lethargy Decreased consciousness Often no signs
Diagnosis of SDH
CT scan- smooth crescent shaped bleed
Oedema present, usually over the haematoma but can be diffuse
Management of SDH
Analgesia, fluids and NBM
Midline shift more than 5mm or focal signs- evacuation
Otherwise watchful waiting and serial CT scans
Definition of SAH
Haemorrhage of blood into the subarachnoid space
Causes of SAH
Trauma (most common)
Ruptured intracranial aneurysm (assoc with PKD, ehlers danlos and aortic coarctation)
Cerebral AVM
Others- CA rupture or dissection, coagulation disorders, idiopathic
Sx of SAH
Sudden onsent severe, thunderclap headache Nausea and vomiting Syncope or apoplexy Neck pain Photophobia
Signs of SAH
Focal nerve issues Increased ICP and coma Meningismus with positie Kernig's/Brudzinski sign- key SDH point of difference Occular haemorrhage 3rd nerve palsy HTN
Diagnosis of SAH
CT scan detects >95% of cases within 48h
LP is most definitive but must remember to take only a small amount of CSF due to rebleed risk
Sees increased opening pressure, non clotting bloody fluid, xanthochromia, increased RBC and protein
Cerebral angiogram gold standard for evaluation
Management of SAH
ICU and hourly neuro checks Prophylactic leviteracetam Sedation, analgesics, dexamethasone, stool softener, oxygen, BP management Bloods coliling, clipping bleeders in surgery
Complications of SAH
Vasospasm- need 21 day nimodipine course to prevent
Re bleeds
Hyponatraemia secondary to SIADH but must give saline, not diuretics and fluid restriction
Seizures
Hydrocephalus
Definition of hydrocephalus
Excessive volume of ECF within the ventricular system due to production absorption-imbalance
Causes of hydrocephalus (categories)
Obstructive/non communicating
Non obstructive/communicating
Normal pressure
Cause of obstructive hydrocephalus
Blackage of CSF flow by a structure such as
tumour
avm
post haemorrhage
Aqueductal stenosis
Chiari malformation (brain tissue extending into spinal cord)
Causes of non obstructive hydrocephalus
Reduced reabsorption due to
meningitis
post-haemorrhage
Increased production due to a choroid plexus tumour
Causes of normal pressure hydrocephalus
Often idiopathic
Symptoms and signs of hydrocephalus
O/NO: Increased ICP so
- Headache, worse in morning lying and valsalva
- Nausea/vomiting
- Papilloedema
- upgaze/abducens palsy
- Gait change
Paeds
- Bulging fontanelle
- Increased head circumference relative to face size
- Reduced upward gaze
Normal pressure
- TRIAD: dementia, incontinence and disturbed gait
Investigations for hydrocephalus
CT suggests enlargement of temporal horns
LP is diagnostic and therapeutic but NOT if obstructive due to risk of brain herniation
Management of hydrocephalus
Surgical: Shunt / 3rd ventriculostomy / choroid plexectomy / external ventricular drain if acute or severe
Medical: Diuretics, but only temporarily and cocasionally in infants
What is the cushings reflex
Occurs late and often pre-terminal following brain trauma
- Bradycardia AND hypertension
What does a unilateral pupil dilation and sluggish/absent light reflex mean
3rd nerve palsy
May be due to tentorial herniation
What does a bilateral pupil dilation and sluggish/absent light reflex mean
Poor perfusion
Bilateral 3rd nerve palsies
What does unilateral normal/dilated pupil with marcus gunn light reaction mean
Optic nerve injury
What does bilateral constructed pupils with a difficult to visualise light reflex mean
Opiates
Pontine lesion
Metabolic encephalopathy
What does unilateral constructed pupils with a normal light reflex mean
Sympathetic disruption (eg. horners)
Definition of trigeminal neuralgia
A pain syndrome characterized by severe unilateral pain
Causes of trigeminal neuralgia
Often compression of trigeminal nerve by the SCA
Idiopathic
Tumour
Vascular anomalies (rare)
Signs and symptoms of trigeminal neuralgia
Unilateral electric shock like pains coming and going abruptly Commonly evoked by light touch Frequently spontaneous Shows periods of remission No other neurology present
Red flags for trigeminal neuralgia
Sensory changes Hearing or ear issues History skin or oral lesions that may spread Bilateral pain Solely ophthalamic pain Optic neuro issues personal or familial MS Under 40yo
Management of trigeminal neuralgia
Carbamazepine 1st line
Peripheral branch blocks or neurectomy
Definition of aneurysm
A weakening of the arterial wall leading to a pressurized outpouch
Causes of aneurysm
Congenital with a defective muscular layer of artery (called medial gap) Hypertension Embolic due to atrial myxoma Infection Trauma
Varieties of aneurysm
Berry/saccular: Normally major vessels and apex of branch points such as ant or post communicating arteries
Fusiform- all sides bulge, more common in basilar circulation
Symptoms of aneurysm
Rupture is the most common presentation- SAH May also cause intracranial, intraventricular or subdural bleeds Mass effect- hemiparesis Cranial neuropathy of 3rd nerve Visual loss facial pain Headache TIA Seizure
Management of aneurysm
Coiling by IR- good for elderly, poor clinical grade, post. circulation, small necked aneurysm, inaccessible by clip
Clipping via surgery- good for young, MCA, giant, mass effect, small, wide necked aneurysm, previous coil failure
Otherwise control HTN, soften stool etc
Define AVM
A vascular abnormality usually congenital and incidentally found if asymptomatic
Blood flows directly into draining veins without capillary beds
Causes of AVM
Congenital
Often progress from low to med/hi pressure
Symptoms of AVM
Haemorrhage most common presentation Headache Seizure Ischaemic sx by steal Face or limb weakness Mass effect
Diagnosis of AVM
Unenhanced CT rules out active bleeds
MRI for examining AVM and oedema
Angiography shows tangle, feeding and draining vessels
Graded by spetzler-martin system
Management of AVM
Depends on grade and symptoms Surgery is treatment of choice Radiation Endovascular embolization Combination therapy
Describe glioblastoma
Most common primary tumour
Disrupts BBB
Assoc with vasculogenic oedema
How does glioblastoma show on imaging
Solid centrally necrotic tumour with an enhancing rim
Pleiomorphic cells on histology
Treatment of glioblastoma
Surgery
+/- adjuvant chemo/rad
Dexamethasone for oedema
Describe meningioma
2nd most common primary brain tumour
Typically benign
Arise from dura mater
Where are meningiomas found
Falx cerebri, sup saggital sinus, skull base
Causes sx due to mass effect
How does meningioma show on imaging
CT- contrast enhancement
MRI useful
Histology shows spindle cells in concentric whorls, calcified psammoma bodies
Treatment of meningioma
Watch and wait
If troublesome sx- surgery +/- radiotherapy
What cancers commonly metastasize to the brain
Lung Breast Kidney Colorectal Skin
Describe 3rd nerve palsy sx
Eye is down and out
Drooped eyelid
Constricted unilateral pupil
Describe 4th nerve palsy sx
Affected eye moves upwards the more medially it looks
Describe 6th nerve palsy sx
Affected eye cannot look laterally
