Neuro Flashcards
Name the three most common scoring systems in the UK for grading the severity of SAH
World Federation of Neurological Surgeons (WFNS) (clinical)
Hunt & Hess (clinical)
Fisher grade (CT grading)
What are the causes of SAH?
Rupture of berry aneurysm
Rupture of AVM
Traumatic SAH
Name some risk factors for developing aneurysmal SAH
Smoking Polycystic kidneys Cocaine use Amphetamine use Ehler’s Danlos Genetic
Name some early neurological complications of SAH
Rebleeding
Seizure
Hydrocephalus
Name some later neurological complications of aneurysm SAH
Delayed cerebral ischaemia/vasospasm
Cognitive impairment
Neurocognitive symptoms - low mood/sleep disturbance
Hypopituitarism
List some indications for awake craniotomy
Epilepsy surgery
Tumour resection in eloquent areas of brain
DBS
List the absolute contraindications to awake craniotomy
Cannot lie still
List the relative contraindications to awake craniotomy
Learning difficulties Airway concerns - OSA Chronic cough Anxious patients Language barrier Children unable to cooperate
Name 3 anaesthetic approaches to awake craniotomy
- Asleep -> awake
- Asleep -> awake -> asleep
- Sedation - awake throughout
- No sedation/regional only (uncommon)
What intraoperative adverse incidents may occur in an awake craniotomy?
Airway problems & hypoventilation Conversion to GA required Seizure Air embolism Patient intolerance/revoking consent
Describe the flow of CSF in the brain
Choroid plexus in the LATERAL ventricles -> Foramen of Munro -> THIRD ventricle -> Sylvian aqueduct -> FOURTH ventricle -> Foramen of Magendie & Luschka -> spinal canal -> arachnoid villi ->dural venous sinuses
What are the clinical features of acromegaly?
OSA Coarsening facial features - macroglossia, prognathism, big ears Carpal tunnel syndrome Soft tissue changes - increased sweating, big hands Headache Hypertension T2DM Cardiomegaly/cardiomyopathy Vocal cord hypertrophy - deep voice
During trans-sphenoidal resection of pituitary tumour, the surgeon asks you to facilitate the descent of the pituitary into the operative field. How could you do this?
- Controlled hypercapnoea (decrease MV)
- Injection of saline into a lumbar drain
What follow up do patients need post pituitary resection?
IGF-1 levels
Colonoscopy
Visual fields
What are the endocrine complications of pituitary tumour resection?
Diabetes insipidus
Adrenocortical deficiency
Panhypopituitarism
What are the neurosurgical complications post pituitary adenoma resection?
CSF leak/rhinorrhea
Vascular injury - carotid artery
Optic nerve injury
Nasal septum perforation
Infection - meningitis/sinusitis
Anosmia
What is secondary brain injury and when is it likely to occur?
Deleterious changes that happen over hours/days as a consequence of the initial injury
Mediated by inflammatory, neurogenic and vasogenic processes
What is the pathophysiology of secondary brain injury?
- Reduced cerebral O2 delivery
- Increased CMRO2
- Cellular mechanisms
-Primary injury may exhaust compensatory capacity of brain (e.g. ICH) -> raising ICP & Monro Kelly Doctrine
-Inflammation/local tissue damage -> release of excitatory neurotransmitters causing calcium influx to cells and cell death
-Dying cells release free radicals causing increased blood vessel permeability and causing vasogenic fluid accumulation
-Loss of cerebral auto regulation
-Hypoxia/hypotension/hypercarbia/hypocarbia/hypoglycaemia/hyperglycaemia -> exacerbate secondary brain injury and inhibit auto-regulation
-Seizures cause raised ICP, raised CMRO2 and reduce PaO2
How can secondary brain injury be minimised?
ABCDE: Airway control -> I&V if low GCS/seizures/hypoxic/hypercarbia/unable to protect airway C spine control PaO2 >12 PaCO2 <4.5kPa PEEP for oxygenation but otherwise avoid Maintain MAP >80mmHg (or higher if ICP raised) Allow good venous drainage - head neutral, head up etc Catheterise Seizure control Temp control BM control Sedate to control CMRO2 ICP monitoring
What are the grades of severity with the WFNS for SAH?
- GCS 15, no motor deficit
- GCS 13-14, no motor deficit
- GCS 13-14 with motor deficit
- GCS 7-12 with or without motor deficit
- GCS 2-6 with or without motor deficit