Neurosurgery Flashcards
What is the effect of anterior facing herniation?
Suppression of the anterior cerebral artery
Leg weakness
What is the effect of herniation into the infraorbital fissure?
CN III damage
4 of 6 extraocular muscles
Parasymp nerve
Treatment of raised ICP from CSF:
Drainage
Chronic decrease in production using carbonic anhydrase
Treatment of raised ICP from blood:
Bed at 30 degrees to increase venous return
Decrease PCO2
Decrease inflow, increase outflow
Evacuate clot
Treatment of raised ICP from brain:
Decrease CMRO2 (oxygen consumption)
Steroids acutely reduce vasogenic swelling from tumour
Remove tumour
Hypertonic solution (e.g. saline 3%)
How do you test for brainstem death?
Pupil response
Corneal reflexes
Oculovestibular reflexes
Apnea test
Indications for brainstem death:
Hypothermia
Circulatory disturbances
Electrolyte and endocrine disturbances
Lack of reflexes
Decorticate posture:
Arm adduction
Elbow flexion
Hand flexion
Plantar flexion
Decerebrate posture:
Arm adduction Elbow extension Forearm supination Hand flexion Plantar flexion
How do space-occupying lesions present?
Focal deficits
Seizures
Raised ICP
Signs of raised ICP in a neonate?
Head circumference Fontanelle Dilated scalp veins Loss of upgaze Irritability, vomiting, reduced conscious level
MRI modalities:
T1 for contrast (tumours)
T2 for anatomy
Communicating causes of hydrocephalus:
Post-haemorrhage
Post-infection
Non-communicating (obstructive) causes of hydrocephalus:
Aqueduct stenosis Obstructed outlets of the 4th ventricle Foramina of Monro Tumour Blood, infection Membranes and cystic lesions
Difference between communicating and non-communicating hydrocephalus:
Communicating = outflow obstruction outside of the ventricles (flow between the ventricles) Non-communicating = outflow obstruction in the ventricles
Triad of features in normal pressure hydrocephalus:
Dementia or bradyphrenia (slowness of thought)
Urinary incontinence
Gait difficulties (similar to Parkinson’s)
Imaging of normal pressure hydrocephalus:
Hydrocephalus with enlarged 4th ventricle
Absence in sulcal atrophy
Treatment for normal pressure hydrocephalus:
Ventriculoperitoneal shunting
10% experience serious complications such as seizure, infection and intracerebral haemorrhage
Most common solid tumour in children/2nd most common cancer in children to leukaemia?
Posterior fossa brain tumour
Effect of pineal tumour?
Can cause hydrocephalus by compressing the aqueduct
History of aneurysm?
Crescendo over seconds to a really bad headache
Risk factor for aneurysms:
Connective tissue disorders
Poor prognostic factor in aneurysm:
Vasospasm
Give nimodipine
Extradural tumour:
Metastases from prostate cancer
Intradural tumours:
Meningioma
Neurofibroma
Intramedullary tumours:
Astrocytoma
Ependymoma
Haemangioblastoma
Cavernoma
Presentation of hydrocephalus in older children/adults:
Headaches
N+V
Visual blurring +/- loss of upgaze
Drowsiness, reduced conscious level
Imaging in hydrocephalus:
US in neonates
Need higher resolution before intervention like CT or MRI to observe flow
Temporary treatment of hydrocephalus:
Extra-ventricular drain
Ventriculosubgaleal shunts (drains to under scalp)
Resevoir
Definitive treatment of hydrocephalus:
Shunt
ETV
Fenestrations
Stents
Head injury severity by GCS:
Mild = 13-15 Moderate = 9-12 Severe = 3-8
What causes subdural haematomas?
Rupture of bridging veins or burst lobes in severe head injury
What causes extradural haematomas?
Fracture lacerating dural artery
MMA
Venous sinus injury
May have lucid interval
What are multiple small contusions (petechial haemorrhages) a sign of?
Diffuse axonal injury
Management of DAI pre-surgery?
Insertion of ICP probe to monitor
Management of brain tumours:
Initially steroids to reduce swelling
AEDs if needed
MRI of whole neuraxis and CT CAP
Surgery
Management of glioblastoma?
High grade glioma
Resection and chemoradiation
Prognosis is 1.5 years
Management of single metastasis?
Resection
Low grade gliomas will…
Transform to high grade within 15 years
Maximal resections carried out to prevent this
Management of malignant tumours e.g. medullary blastoma in neonate?
Resection with curative intent and adjuvant therapy
Avoid RT/proton beam in first 3 years of life
Astrocytoma treatment?
Maximal safe resection
What is a cavernoma?
Cluster of abnormal blood vessels typically in CNS
Thin walls, prone to leaking
Can cause seizures, strokes, haemorrhages and headaches
Where do hypertensive bleeds tend to occur?
Basal ganglia
Cerebellum and brainstem but to a lesser extent
Management of aneurysm?
HDU/ITU
Analgesia, laxatives, fluids
Nimodipine
CT angiogram to discuss coiling/clipping
Spinal tumours:
Extradural > intramural > intramedullary
Grade A spinal trauma:
Complete. No motor or sensory in sacral segments S4-5
Grade B spinal trauma:
Incomplete. Motor below neurological level but no sensory. Includes sacral segments S4-5
Grade C spinal trauma:
Incomplete. Motor below neurological level and more than half muscles below neurological level have grade 3 or less
Grade D spinal trauma:
Incomplete. Motor below neurological level and more than half muscles below neurological level have grade 3 or more
Grade E spinal trauma:
Normal. Motor and sensory intact
