Neurosurg 2 Flashcards
Most common pathogen of brain abscess
Streptococcus
Brain abscess pathogen in neonates
Proteus
Citrobacter
Brain abscess pathogen in penetrating injury
Staph
Brain abscess pathogen in ImmComp
Fungi
Protozoa
The most common route for brain abscess
Hematogenous, from lung
Epidural abscess associated with:
Osteomyelitis
RFs for cerebral abscess
Lung abn:
Infection
AV fistula
Osler-Weber-Rendu
Congenital heart disease:
R- to L-shunt
Bacterial endocarditis
Penetrating trauma
ImmSup
Dental abscess, poor dentition
Inv for brain abscess
CT (first in ED)
MRI (test of choice)
CBC, ESR,
B/C
LP CONTRAINDICATED IF LARGE MASS.
CSF: high ICP, high WBC, high protein, normal glucose, negative culture
Tx if brain abscess
Aspiration +/- excision:
Gram stain, AFB, Cand, fungal culture
AB:
Vanco + Cefriaxone+ metro/chloramphenicol/rifampin (6-8 wk)
Adjust AB with C&S
Anti-convulsants 1-2 yr
F/U CT
Lucid interval seen in:
Epidural hematoma
1st: post-traumatic reduced LOC
2nd: lucid interval of several hours
3rd: deterioration continuing hours to days
Etiology of epidural hematoma
Skull fx (often middle meningeal artery bleed)
CT of epidural hematoma
Hyperdense Lenticular Sharp margins Limited by suture lines Not limited by dural attachments
Tx of epidural hematoma
Admission
Close observation + serial CT if: Small volume clot \+ minimal midline shift (<5mm) \+ GCS (>8) \+ no focal deficit
Otherwise, Craniotomy and F/U CT
If EDH in temporoparietal region, or EDH > 10 mm in first 2 h, take F/U CT at 5-6 h post inpact
Mannitol if rised ICP
Good prognosis if prompt Mx
Age of subdural hematoma
> 50
Associations of subdural hematoma
Acute: Age> 50 Trauma (acceleration-develeration injury) Anticoag Alcohol Cerebral atrophy Infant head trauma
Chronic: Age > 50 (older) EtOH CSF shunt Anticoagulated/coagulopathy
CT of subdural hematoma
Acute:
Hyperdense
Crescentic
Crossing suture lines
Chronic:
Hypodense
Crescentic
Crossing suture lines
Tx of subdural hematoma
Acute: craniotomy if > 1cm thick or mid-line shift>5mm (optimal if surgery <4h)
Chronic: burr hole to drain (if symptomatic or thickness> 1cm), craniotomy if recurs more than twice.
Seizure prophylaxis only if post-traumatic seizure.
Reverse coagulopathy
Prognosis of subdural hematoma
Acute: poor
Chronic: good
CT of SAH
Hyperdense blood in cisterns/fissures
Tx of SAH
ICU/NICU O2/ventilation NPO Bed rest, elevated head 30° Minimal external stimulation Neurological vital signs q 1h IV NS+ KCl ECG Foley BP: 120-150 Nimodipine: vasospasm Px, neuroprotection Levetiracetam (seizure prophylaxis) Mild sedation
Endovascular surgery to repair if rebleed
Prognosis of SAH
50% mortality
Etiology of ICH
HTN Vascular abn Tumor Infection Coagulopathy
Age>55 Male Cocaine EtOH Amphetamine
CT of ICH
Hyperdense intraparanchymal collection
Tx if ICH
Decrease BP
Control ICP
Craniotomy
CT, MRI T1, MRI T2 for intracranial bleeds within 72 h
CT: hyperdense
MRI T1: Grey
MRI T2: Black
CT, MRI T1, MRI T2 for intracranial bleeds <3 wk (subacute)
CT: isodense
T1: white
T2: white
CT, MRI T1, MRI T2 for intracranial bleeds > 3 wk (chronic)
CT: hypo
T1: Black
T2: Black
How to remember MRI changes in bleeding
MRI T1: George Washington Bridge
MRI T2: Orio: Black, White, Black
Which intracranial bleeding is the great imitator of dementia)
Chronic SDH
Most common cause of SAH
Trauma
Others: spontaneous (aneurism, AVM), coagulopathy, idiopathic,…
Peak age of SAH
55-60
RFs for SAH
HTN Pregnancy, partirition if pre-existing AVM Eclampsia OCP Cigarette Cocaine Alcohol
Inv for SAH
Non-contrast CT
If negative CT, but high suspicion: LP
Opening pressure > 18
Bloody
Xanthochromic if centrifuged (by 12hr)
Lasts 2wk
RBC > 100,000, without significant drop in last tube
Elevated protein
MRA, CTA to find aneurysm
Gold standard for aneurysms: four vessel cerebral angiography. Repeat in 7-14 d if negative
Complications of SAH
Vasospasm:
Onset: 4-14d
New onset ischemic defect, infarct, death
Dx with transcranial doppler or clinical
Delayed cerebral ischemia:
4-10 d
Hydrocephalus:
Acute or chronic
Tx: extraventricular drain or shunt
Neurogenic pulmonary edema
Hyponatremia
DI
Cardiac arrhythmia, MI, CHF
Prevention of SAH
Early clipping or coiling of eneurism
Most common type of intracranial aneurysms
Berry
Mostly in carotid system
Most common location for saccular aneurysms
AComm
Fusiform aneurisms etiology and location
Atherosclerosis
Vertebrobasilar system
Mist common cause of infectious aneurysms
Strep and staph
RFs for aneurysms
ADPKD
Fibromascular dysplasia
AVM
Ehlers-Danlos
Marfan
FHx
Bacterial endocarditis
Osler-Weber-Randi
Atherosclerosis
HTN
Trauma
Smoking
Sentinel hemorrhage
SAH Sx for < 24 h
May have blood on CT or LP
Requires urgent clipping/coiling of aneurism to prevent Catastrophic bleed
The most common clinical presentation of aneurism
Rupture
Inv for aneurysm
CTA
MRA
Angiography
Tx of aneurism
Ruptured:
Early surgery or coiling (within 48-96h)
Unruptured:
Treat if > 10 mm
Or 7-9 mm in middle aged, young, FHx
If smaller: F/U with serial angio
Drugs causing ICH
Amphetamines
Cocaine
Alcohol
Anticoagulants
RFs for ICH
>55 Male HTN Black/asian > caucasian Previous CVA Heavy alcohol use, cocaine, amphetamines Liver disease Anticoag
Inv for ICH
Severity score
Non-contrast CT
CTA
Tx of ICH
Decrease MAP (target 140-90) Correct coagulopathy Control raised ICP SEIZURE Px: levetiracetam, phenytoin Follow lyes Angiogram to R/O vascular lesions (unless > 45y, known HTN, putamen/thalamic/posterior fossa ICH)
Surgical if: Symptoms of raised ICP or mass effect Rapid deterioration Favourable location Young (> 50) If tumor, AVM, aneurysm
Contraindications to surgical Tx of ICH
Small bleed, minimal symptoms, GCS>10
Poor prognosis, low GCS, lost BS function
Very old
Severe coagulopathy
Difficult location
AVM facts
M, 33yr
Sx:
Small ones: hemorrhage
Large ones: seizures
Focal neurological signs (steal phenomenon)
Localized headache
Bruit
Inv for AVM
MRI
MRA
Angio
Tx of AVM
Choice: surgical excision
If <3cm or very deep:
Stereotactic radiosurgery
+/- Endovascular embolization
Conservative, palliative embolization
Sx of cavernous malformation
Seizure
Progressive neurological deficit
Hemorrhage
H/A
Dx of cavernous hemangioma
MRI T2: non enhancing
Best method for Dx: gradient echo sequencing
Tx of cavernous hemangioma
Surgical excision if:
Symptomatic, surgically accessible
Dural fistula Sx
Asymptomatic
Pulsatile tinnitus
Bruit
Headache
If carotid cavernous involvement:
Proptosis
Chemosis
Bruit
Inv for dural fistula
Non-contrast CT to R/O hemorrhage
MRI
Gold std: Angio
Tx of dural fistula
Conservative
Endovascular interventions
RT
Surgery
Sx of CSF fistula
Otorrhea
Rhinorrhea
Recurrent meningitis
Low pressure headache (worse with sitting)
Inv for CSF fistula
Fluid B-transferrin test,
Quantitative glucose analysis of fluid
Ring sign
Reservoir sign
CT (defect, fx, pneumocephalus)
Water contrast CT cysternography
Tx of CSF fistula
Lower ICP:
Avoid straining
Acetazolamide
Modest fluid restriction
Persistent leak: continuous lumbar drainage
Surgery: Leak > 2 wk after trauma. Spontaneous leak Delayed onset of leak after trauma or surgery Leak complicated by meningitis
Most common cervical disc herniation
C6-C7
Pressure on C7
Cervical disc syndrome Sx
Pain in arm following nerve root
Pain is referral , non dermatomal
Worse with neck extension
Worse with ipsilateral rotation
Worse with lateral flexion
LMN signs and symptoms
Myelopathy if central protrusion
Inv for cervical disc syndrome
If red flags:
C-spine x-ray, CT, MRI (choice)
If peripheral nerve issue and uncertain Dx:
EMG, NCS
Tx of cervical disc syndrome
No bed rest (unless severe)
Activity modification, pt education:
Reduce sitting, lifting
PT, exercise to strengthen core muscles
NSAIDs
Avoid manipulation, traction
95% improve in 4-8 wk
Surgery if:
Intractable pain despite 3 mo conservative Mx
Or
Progressive neurological deficit
Sensory, motor, reflex Sx in C4-C5 disc syndrome
C5
S: shoulder
M: deltoid, biceps, supraspinarus
R:-
Sensory, motor, reflex Sx in C5-C6 disc syndrome
C6
S: thumb
M: biceps
R: biceps, brachioradialis
Sensory, motor, reflex Sx in C6-C7 disc syndrome
C7
S: middle finger
M: triceps
R: triceps
Sensory, motor, reflex Sx in C8-T1 disc syndrome
C8
S: 5th finger
M: digital flexors, intrinsics
R: Hoffmann (finger jerk)
The most common cause of spinal cord impairment
Cervical spondylotic myelopathy:
Degenerative process of cervical spine leading to canal stenosis
Includes: Disc degeneration/herniation Osteophyte Ossification/hypertrophy of ligaments Congenital stenosis Subluxation Alteration of normal lordosis Altered mobility
Cervical spondylosis Sx
Mechanical neck pain, exacerbated by excess vertebral motion (esp rotation and lateral bending)
Gait disturbance, lower extremities weakness or stiffness (early Sx)
Occipital H/A
Radiculopathy (neck, shoulder, arm pain, paresthesias, numbness)
Myelopathy (upper weakness> lower), decreased dexterity, sensory changes, UMN findings (hyperreflexia, clonus, babinski), funicular pain (burning and stinging +/- Lhermitte)
C5-C6 > C6-C7