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MBBS III Summative WCS Neurosurgery
Fichas del conjunto (41)
- 1Normal ICP in human- adult <10-15mmHg
- >20 definitely abnormal
- intracranial contents: blood+brain+CSF - 2Cx of untreated raised ICP- cerebral ischemia
- brain herniation
- brainstem insult
- respiratory arrest
- coma
- death - 3Causes of intracranial hypertension- mass e.g. tumor, hematoma
- hydrocephalus: communicating/obstructive
- focal/diffuse brain swelling --> ischemia
- hyperemia
- venous congestion - 4Clinical features of raised ICP- headache, vomiting: worst in the morning, better at night, relieved by lying supine
- blurring of vision
- deterioration in consciousness
- ipsilateral/bilateral dilated pupil
- papilloedema (late)
- Cushing's triad of hypertension, bradycardia, irregular breathing (late) - 5Components of GCS1. Eye opening:
- spontaneous (4)
- to voice (3)
- to pain (2)
- none (1)
2. verbal response:
- oriented (5)
- confused convo (4)
- inappropriate words (3)
- incomprehensible sounds (2)
- none (1)
3. motor response:
- obeys command (6)
- localizes pain (5)
- normal withdrawal flexion (4)
- abnormal flexion (3)
- extension (2)
- none (1) - 6ICP monitoring- indicated when no other reliable methods to monitor ICP available and GCS≤8
- relatively CI in awake patients with coagulopathy
- gold standard
- allows therapeutic CSF drainage
- but can cause infection and it's invasive, difficult to use in cerebral edema - 7Rx of raised ICP- assess ABC and resuscitate
- if GCS low, assume lost airway, open airway
- ensure C spine fixed, but remove head collar if not indicated
- enhanced venous drainage: avoid neck rotation, prop up to 30-45 degrees
- controlled hyperventilation: DO NOT over, otherwise reduced CBF
- mannitol, diuretics: can cause hypotension, hyperosmolality, need to monitor UO
- steroids in tumor NOT trauma
- barbiturate coma: SE of hypotension and myocardial depression, monitor EEG
- induced hypothermia: SE of coagulopathy
- drainage of CSF
- evacuation of mass lesion
- decompressive craniectomy - 8CSF drainage- ventriculo-peritoneal/atrial/pleural
- lumbo-peritoneal
- Cx: infection, blockage, overshunting --> subdural hematoma, dislodgement, abd pseudocyst - 9Mx of suspected shunt infection- exclude blocked shunt
- obtain CSF specimen
- exclude distal end infective foci e.g. abd sepsis
- antibiotics
- sondier removal/externalization of shunt - 10Presentation of brain tumors- raised ICP
- focal neurological deficits: neuronal damage, pressure effect, edema
- epilepsy (for supratentorial lesions only, i.e. NOT cerebellar): partial, grand-mal, complex partial (TLE)
- others: facial pain, bitemporal hemianopia - 11Clinical features of uncial herniation- herniation of uncus of temporal lobe through tentorium
- third nerve palsy, dilated pupil
- cerebral peduncle, contralateral hemiplegia
- brainstem compression, impaired consciousness
- Kernohan's notch: ipsilateral hemiplegia, false localization sign (compression of contralateral cerebral peduncle) - 12Clinical features of tonsillar herniation- posterior cranial fossa
- cardiorespiratory arrest
- impaired consciousness
- decorticate/decerebrate posture - 13Clinical features of central herniation- herniation of diencephalon
- bilateral small pupil
- Cheyne-stokes respiration
- unconscious - 14Clinical features of cingulate herniation- displaced cingulate gyrus --> subfalcine shift
- ACA may be compromised
- non-specific clinically - 15General modalities of Rx for intracranial tumors- anticonvulsants if established epilepsy
- steroids to reduce/reverse cerebral edema
- surgery: cytoreduction within maximal safety limit and resection margin, CSF shunting for hydrocephalus for posterior cranial lesions, leptomeningeal/CSF metastasis
- radiotherapy: delivery either through external beam or interstitial implant, dosage either single dose or fractionated
- radiosurgery: x-knife, gamma-knife - 16Causes of intracranial tumor- commonest: met from extra cranial primary e.g. lung, breast, renal cell, colon
- primary brian tumor
- needs to differentiate from brain abscess by CT/MRI/angiogram - 17Rx for brain tumors- brain metastasis: surgery + WBRT if good function, young age, reasonable life expectancy, good control of original tumor, if not, maybe RT only
- gliomas: adjuvant chemotherapy post-op e.g. temozolomide (alkylating agent, used with ERT then adjuvant for 6 cycles, SE BM suppression), bevacizumab (anti-angiogenesis agent)
- meningioma: first choice surgery, can do adjuvant wide-field ERT or radio surgery - 18Ix for pituitary tumor- MRI with contrast +/- dynamic studies
- visual: clinical, perimetry
- endocrine hormonal tests - 19Indications and Cx of surgery for pituitary tumorsIndications:
- symptomatic non-secreting macroadenoma (>10mm)
- GH-secreting adenoma
- ACTH-secreting adenoma
- NOT prolactinoma: can be controlled by drugs alone
Cx:
- DI, hypopituitarism
- visual loss
- CSF leakage and meningitis
- intracranial haemorrhage
- vascular injury e.g. stroke
- ENT symptoms - 20Clinical features of pituitary apoplexy- neurosurgical emergency
- meningism
- vertigo
- +/- visual defects, altered consciousness - 21definition and causes of coma- severe impaired consciousness
- GCS E1M5V2
- impaired brainstem reflexes
- decorticate posture (flexor, intact red nucleus)
- decerebrate posture (extensor, damaged red nucleus)
- causes: intracranial VS extracranial, intracranial traumatic, vascular (most common, leads to raised ICP and seizure), neoplastic, infective - 22Pain receptors in "brain"Intracranial:
- venous sinus
- basal arteries
- cortical veins
- dura mata
extracranial (referred):
- scalp muscles and vessels
- orbital contents
- mucous membranes
- external & middle ear
- teeth & gum - 23Presentation of life-threatening causes of headaches- due to sudden increase in ICP
- distinct onset
- severe pain
- +/- deterioration of consciousness
- vomiting, with transient relief of headache after
- focal neurological deficit
- meningism: neck stiffness, Kernig's sign, photophobia - 24Mx of ischemic stroke- therapeutic window 3 hours: tPA thrombolysis
- 1st line: anti-platelet
- 2nd line: surgery including carotid endarterectomy (open), endovascular thrombolysis & shunting, endovascular balloon angioplasty & stenting
- after infarct established: ICP control and decompressive craniectomy for cortical lesions
- for cerebellar lesions: ventriculostomy, suboccipital craniectomy, infarctectomy to prevent hydrocephlus --> brainstem herniation - 25Types and causes of haemorrhagic strokeTypes:
- cerebellar: surgical emergency, treatable!
- brainstem, thalamic: poor prognosis
- lobar: good prognosis
- SAH: emergency!!
Causes:
- HT
- vascular malformation: AVM, aneurysm, cavernoma
- haemorrhagic transformation after infarction
- tumor - 26Clinical features of SAH- commonest cause is trauma, after is ruptured aneurysm
- rupture Sx: worse occipital headache, LOC, meningism, fundoscope shows subhyaloid haemorrhage
- mass effect: visual loss (opthalmic artery), CNIII palsy (PComA artery)
- thrombo-embolism --> ischemic stroke
- diagnosis by CT, CT-negative LP xanthochromia in 3-bottle test (differentiate form traumatic tap), MRI (not sensitive at early stage)
- later stage: DSA, CTA, MRA - 27Mx of SAH- rebleeding: starts on day 1 peaks on day 14, open microsurgical clipping/endovascular coiling
- vasospasm: starts on day 4 peaks on day 7-10, delayed cerebral ischemia due to blood in CSF, drugs: nimodipine, triple H hypertension, hypervolemia, hemodilution, angioplasty
- hydrocephalus: slow and controlled CSF drainage - 28Presentation and Rx of AVM- haemorrhage (commonest)
- seizure
- headache
- ischemia (vascular steal)
- others: bruit, hydrocephalus, heart failure
- risk of bleeding = 3% each year
- Rx: surgerical excision, embolization, radiosurgery - 29Dermatome along anterior axillary line- shoulder: C5
- nipple: T4
- umbilicus: T10
- groin: L1
- big toe: L4 - 30Sphincter disturbance = A POINT OF NO RETURN- acute painLESS urinary retention
- constipation
- irreversible after 4-6 hours of onset - 31Types of spinal cord injuryComplete cord transaction:
- complete motor and sensory loss at and below level, sphincter disturbance
- e.g. transverse myelitis
Incomplete:
- Brown-sequard syndrome
- Central cord syndrome
- Anterior cord syndrome (spinal artery)
- Posterior cord syndrome - 32Autonomic dysreflex in neurogenic/spinal shock- lesion above T6
- late problem, emergency!
- due to uncontrolled sympathetic discharge
- stimuli: most commonly full bladder (distention) leading to vasoconstriction, hypertension despite bradycardia (sympathetic response)
- vagal bradycardia - 33Causes of SoL in spinal cord1. neoplastic: primary/secondary
2. traumatic: bone fragment, hematoma
3. degenerative: prolapsed IV disc, osteophyte
4. infective: TB, abscess
5. cystic: arachnoid cyst, syringomyelia
6. vascular: AVM - 34Mechanism of spinal injury- intact ligament (stable): vertical loading compression, hinge injury
- disrupted ligament (unstable): hinge injury, fall from height - 35Signs of spinal trauma- spinal tenderness over spinous process
- flaccid paralysis + no Babinski's
- muscle weakness + areflexia
- sensory loss
- painless urine retention
- lax anal tone
- priapism - 36Ix and Rx for spinal trauma- neck x-ray: lateral, AP, open-mouth view
- CT brain
- MRI spine
- Rx: methylprednisolone (controversial), surgical depression - 37Types of spinal tumor and radiological presentation- extradural: metastasis, primary bone
- intradural extramedullary: meningioma, nerve sheath tumor
- intradural intramedullary: astrocytoma, ependymoma
- on plain x-ray: loss of pedicle shadow, widening interpedicular distance, thinning of pedicles
- contrast block - 38Mx for spinal tumor- steroids
- surgical resection within safety limit
- adjuvant radiotherapy
- radiotherapy for primary tumor - 39Spondylosis changes in cervical spine- disc degeneration
- instability
- apophyseal joint damage
- narrow spinal canal
- joint hypertrophy - 40Rx for degenerative spineConservative:
- physiotherapy
- pain relief
Surgery:
- intractable pain
- myelopathy, radiculopathy
- progressive neurological deficit
- anterior: laminectomy for wide cord decompression
- posterior: foraminotomy for nerve root decompression - 41Types of spinal dysraphism- myelomeningocele
- meningocele
- spina bifida occulta --> tethered cord syndrome (early detection by urodynamic studies and surgical untethering to prevent spinal dysfunction)
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- Descripción
- Fichas sobre MBBS III Summative WCS Neurosurgery, creado por pris_0727 el 23/04/2014.
- Creado por
- pris_0727 · abr 2014
- Actualizado
- 28 sep 2016
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