Neurosurgery Flashcards
Discuss a concussion
Concussion is an alteration in mental status that may or may not involves loss consciousness
- have rapid onset of short lived impairement of neurologic function that resolves spontaneously
Discuss the primary and secondary insults for head injury
Primary: injuries as a consequence of direct impact resulting in permanent damage
Secondary: disturbance due to indirect consequence of traumatic brain injury following the primary insult which are treatable
- hypoxia, ischemia, hematima, raised ICP, seizure, infection and fluid&electrolyte imbalance
Discuss the presentation and management of epidural hemorrhage
Epidural:
- caused by the middle meningeal artery from a temporal-parietal skull fracture
Presentation
- talk and die
- reduced level of consciousness leading to obtundation, hemiparesis and pupil dilation
Investigation
- biconvex, lens shaped hyperdensity that stops at the suture lines
Management
- low risk (small clot with midline shift <5mm and GCS >8) then observe with serial CT
- craniotomy for decompression
Discuss the presentation and management of subdural hemorrhage
Subdural: - caused by cerebral veins - risk with cortical atrophy, anti-coagulant, alcohol Presentation - altered level of consciousness - pupil irregularity Investigation - concanve hypersensitivity Management - poor prognosis due to damage of parenchyma
Discuss intracranial pressure and its relation to cerebral blood flow
Intracranial pressure is brain volume + cerebral blood volume + CSF volume
- means that will increase if any of those increase
- as volume increases the brain spatially compensate by displacing CSF and blood, as this is continues though reaches threshold where have decompensation and large increase in ICP
Cerebral blood flow is cerebral perfusion pressure/cerebral vascular resistance which MAP - ICP/CVR
- vasoconstriction and vasodilation of cerebral blood vessels allow for auto-regulation
- high ICP (such that CPP <60mmHG) leading to decreased blood flow and ischemia and infarction
Discuss the presentation of high ICP
Presentation:
- headache
- nausea and vomiting
- altered level of consciousness
- blown pupil (CNIII palsy)
- loss of corneal reflex (CNV and CNVII palsy)
- loss of gag reflex (CNIX, CNX)
Indications for ICP monitoring
- severe head injury with abnormal head CT
- severe head injury with normal head CT and 2 of the following: age >40, abnormal motor posturing, SBP <90
Management
- goal is ICP <20 and MAP >90mmHg
- vasopressor and resuscitation for MAP >90
- elevate head of bed to 30 degrees
- intubate to keep pCO2 between 35-45mmHg to prevent vasodilation (to 30-35 to vasoconstrict)
- osmolar diuresis with mannitol 20% or hypertonic saline to remove water from brain
- sedation to reduce hypertension
Discuss the presentation and management of a depressed skull fracture
- comminuted fracture in which broken bones displace inward Presentation - palpable defect Investigation - CT Management - surgery if depressed thickness of cranium >5mm of inner table or complication from area - Ancef antibiotics for 5-7 days
Discuss the presentation and management of basilar skull fracture
Presentation:
- peri-orbital ecchymosis (raccoon eyes)
- retro-auricular ecchymoses (battle sign)
- hemotympanum
- CSF rhinorrhea/otorrhea
Management
- surgical for complication from intracranial hemorrhage
- cranial nerve palsy are usually temporary from compression or contusion, can be treated with corticosteroids
- prolonged CSF leak can treat with prophylactic antibiotics
Discuss the presentation and management of spinal cord injury
Pathophysiology
- fracture of vertebrae
- shear or stretch of spinal cord from severe mechanism
Presentation
- signs: paresthesia, anesthesia, weakness, loss of anal sphincter tone
- step deformity on palpation
- midline tenderness
Spinal shock: loss of sensation, motor function and reflexes (bulbocavernosus, anal wink, withdrawal) lasting hours to days
Neurogenic shock: distributive shock from loss of SNS leading to hypotension and bradycardia with warm extremities
Investigation
- X-ray for screening
- CT scan
Management
- methyprednisolone to reduce inflammation
- surgical decompression
Discuss the management of intracranial hemorrhage
Acute Management
- lower blood pressure
- reverse anticoagulation (fresh frozen plasma, Octaplex and vitamin K)
Short term management
- observe for 1-2 weeks
Long term management
- discontinue anti-platelet or anti-coagulation
Discuss the types of CNS tumours
Primary CNS Tumours - benign: meningioma (34%), acoustic neuroma (10%), pituitary tumour (15%) - malignant: astrocytoma (25%), lymphoma (<5%) CNS Metastasis - lung cancer - breast cancer - melanoma - renal cell carcinoma - colorectal cancer
Discuss the presentation and diagnosis of CNS tumours
Presentation:
- mass effect leading to headache, nausea, vomiting that are worse in morning
- neurocognitive dysfunction
- papilledema
- herniation symptoms (uncal herniation CN3; tonsillar herniation CN5/7, loss of gag reflex CN9/10
- Cushing reflex: bradycardia and hypertension which lead to respiratory depression
- neurological deficit: seizure, dysphasia, sensory loss, weakness
Investigation
- CT or MRI of head
- biopsy
Discuss the presentation and management of astrocytoma
- most common primary intra-axial brain tumour
- adults 40-60years old
- tumours arises from astrocytes and usually occurs in hemispheres
- grade IV is glioblastoma multiforme
Presentation: - nausea, vomiting, headache
- seizure
- focal deficit
Investigation: - CT show mass effect, enhancement, necrosis, and peri-tumour edema
Management - low grade can have surgical resection of tumour, radiotherapy, and chemotherapy to prevent progression
-high grade is improve quality of life with surgical resection, fractionated radiation and chemotherapy
Discuss the presentation and management of meningioma
- genetic mutation with loss of NF2 gene
- tumour arises from meningothelial cells in arachnoid membrane with slow-growing and circumscribed
- extra-axial tumour
Presentation
headache, nausea, vomiting - seizure
- focal deficit
Investigation - CT with extra-axial mass, well circumscribed homogeneous density enhancing along dural border
Management: - Conservative for asymptomatic
- surgery for symptomatic, progressive lesion (<3cm then radiosurgery, >3cm then open)
Discuss the presentation and management of brain metastasis
- hematogenous spread to cerebral hemisphere at grey-white matter junction Investigations - CXR - CT chest and abdomen - bone scan Management - underlying cause - treat complications: seizure prophylaxis and corticosteroids to reduce edema
