5. Cranial Neurosurgery Flashcards
1
Q
What lesion can produce head tilt?
A
Anterior vermis, 4th nerve palsy
In MG - head tilts back
2
Q
Vermicular movement of face with pontine demyelination?
A
Myokymia
3
Q
DBS of ventral intermediate thalamic nucleus for what dx?
A
Parkinson
Essential tremor
4
Q
Dysarthria and clumsy-hand syndrome?
A
Genu of internal capsule
5
Q
Dilute pilocarpine constrict what type of pupil?
A
Addie’s pupil, but not harm dilated
6
Q
Consensual light reflex > direct light reflex
A
Afferent pupillary defect
7
Q
Most common cause of spontaneous diplopia in middle-aged
A
Grave’s
8
Q
Parkinson with vertical gaze palsy?
A
Progressive supranuclear palsy
9
Q
one-and-a-half syndrome - which eye movement is preserved?
A
Abduction of unaffected eye
10
Q
Oculomotor palsy from aneurysm vs diabetic?
A
Diabetes: pain with pupillary sparing
Aneurysm - compress parasympathetic fibers on periphery
11
Q
Ataxia, myoclonus, positive 14-3-3 protein and bilateral sharp waves on ECG?
A
CJD
12
Q
Actual vs absence seizure?
A
EEG, prolactin, muscle enzyme
13
Q
EEG for absence seizure
A
3Hz wave and spike
14
Q
Diplopia of MG vs compressive lesion?
A
Intermittent vs progressive/constant
15
Q
Which EOM if horizontal object appears slanted?
A
SO
16
Q
Test for HTN from pheo vs essential?
A
Clonidine suppression test
17
Q
%L hemisphere dominant in L handed individuals
A
> 75%
18
Q
Clinical symptoms of NPH
A
Gait disturbances (usually first, most pronounced)
Memory loss
Urinary incontinence
Enlarged ventricles on CT but normal pressure of CSF by LP
19
Q
Area involved in cortical inhibition of B&B damaged in NPH
A
Paracentral lobule
20
Q
R/O other dx before NPH
A
Vascular dementia Parkinson Lewy body dementia Cervical spondylotic myelopathy Peripheral neuropathy
21
Q
Pupillary reflex pathway
A
Optic nerve -> superior colliculus -> Edinger-Westphal nuclei -> (third cranial nerve) ciliary ganglion -> short ciliary nerves
22
Q
Causes of circumoral paresthesia
A
Hypocalcemia
Hyperventilation
Syringobulbia
Neurotoxin fish poison
23
Q
Low vs high pitch tinnitus
A
Low: conductive/meniere
High: sensorineural
24
Q
“Transverse smile”
A
Myasthenic snarl with bulbar involvement in MG
25
Facial myokymia
MG, intrinsic brainstem glioma
26
What maneuver to elicit nystagmus of benign positional vertigo?
Dix-Hallpike maneuver
27
Lateral medulla nuclei
```
Inf. vestibular nuclei
Solitary nucleus
Inferior cerebellar peduncle
Descending tract of V
Spinothalamic tract
```
28
Benign positional vertigo characteristics
Position worsens or alleviates symptoms
29
Meniere's disease: clinical findings
Tinnitus, bouts of vertigo, hearing loss
| Can mimic acoustic neuroma
30
Lateral medulla infarct (wallenberg)
```
Vertigo, nausea/vomiting
Ddysphagia
Ipsilateral sensory loss of face pain/temp
Ipsilateral horner
Contralateral pain/temp
```
31
Ptosis from 3rd CN palsy vs horner syndrome?
Horner disappears with looking up
32
Causes of partial ptosis from 1st order Horner syndrome
Posterolateral hypothalamus to intermediolateral cell column (C8-T2)
Arnold-Chiari, basal skull fracture, wallenberg, demyelinating, intrapontine hemorrhage
33
Pharm test for 2nd or 3rd order horner syndrome?
If intact post-ganglionic fibers (1st or 2nd order) - hydroxyamphetamine would dilate pupil
34
Bell phenomenon
Ask to close eye and show teeth
| Eye goes up and out
35
Nutritional causes of dementia
Wernicke-Korsakoff
| Vitamin B12/Folate
36
Heritable disorder - migraine in early life, then TIAs and strokes, then early dementia?
CADASIL
(Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
Notch3 gene - affects blood vessels grow/development
37
How can you tell if patient may improve from shunt for NPH?
Improvement after lumbar CSF drainage
| Beta waves in ICP monitoring
38
Most common cause of cardioembolic stroke
Afib
39
Arteries supply to macular vision
PCA
40
Acoustic schwannomas - early manifestations?
Depression of corneal reflex (CNVII compression)
41
What diameter of carotid vessel feels bruit?
2.5-3mm
42
Cushing syndrome
Moon face, acne, hirsutism, bladness, buffalo-type obesity, purple striae, muscle wasting, osteoporosis, hypertension, infection, DM
43
Dx with upgaze palsy
Perinaud syndrome (tumor in pineal or quadrigeminal plate)
Hydrocephalus
Hypothyroidism/MG/GBS
44
Recurrent meningitis with no predisposing conditions
Children: basal encephalocele
Adult: CSF fistula
45
Cupulolithiasis
Benign positional vertigo
46
What causes horizontal vertigo?
Paresis of 6th CN
| Can occur with pseudotumor cerebri (susceptible to stretch forces with high ICP)
47
Dx with cherry red spot
Tay-sachs
Niemann Picks
Pseudo-Hurler (GM1 ganglioside)
48
Dx with retinitis pigmentosa
Freidrich ataxia
Refsum (polyneuropathy)
Cockayne (premature aging)
Kern-Sayre (oculocraniosomatic neuromuscular)
49
Cerebellar mutism
Mute in children 1-4 days after surgery in vermian lesion resection
50
Classification for CN7
House-Brackman
1: Normal
5: no eye closure
6: paralysis, no tone
51
Recurrent orofacial edema, recurrent 7th nerve palsy, lingua plicata
Melkersson-Rosenthal
52
Herpes zoster oticus
Ramsay-Hunt syndrome
53
Uveoparotid fever
| 7th CNS palsy in sarcoidosis
Heerfrodt
54
Bilateral 7th nerve palsy
Lyme
55
Ips CN6/7 palsy and contralateral hemiparesis
Millard-Gubler
56
Ips CN7 hemispasm and contralateral hemiparesis
Brissaud-Sicard
57
Ips CN7/8 with horizontal gaze paralysis with contralateral hemiparesis
Foville
58
Benign occipital lobe epilepsy in children, induced by sleep
Panayiotopoulos
59
diameter in mm of a 12-French suction tip?
```
3-French = 1mm
12-French = 4mm
```
60
Significance of frontozygomatic point?
On lateral orbital bone (~ 2.5cm from zygoma attachment, which approximates location of sylvian fissure when connected with 75% point (3/4 distance from nasion to inion)
61
Incision reaching zygoma > 1.5cm anterior to ear may interrupt which nerve?
Facial nerve that reaches frontalis muscle
62
Approach to superficial temporal artery
1. trace out with doppler to determine branching pattern
2. sample frontal branch by dissecting artery under microscope
3-5 cm long
63
Inferior frontal gyrus of dominant hemisphere
Broca
64
Trautman triangle
Superior petrosal sinus
Sigmoid sinus
Posterior auricular canal
Access posterior fossa dura anterior to sigmoid sinus
65
Following greater superficial petrosal nerve lead to which ganglion?
Geniculate ganglion
66
What part of the internal capsule lies ver close to the foramen of monro?
Genu
67
What thalamic nucleus may be damaged while opening the body of the choroidal fissure?
dorsomedial nucleus
68
What areas of bone may be needed to be removed to clip a low-lying basilar artery aneurysm?
Posterior clinoid
69
When would you approach an acomm artery aneurysm from left?
Dominant left A1, dome pointing to the right, another left-sided aneurysm
70
Craniotomy - why linear incision?
Increases blood supply to wound
71
Craniotomy - why "lazy S incision"?
prevent incision line in dura from lying directly underneath incision in skin
72
Craniotomy - why flap incision?
scalp blood flow is not compromised
73
Craniotomy - why zigzag incision?
minimize visibility of scalp alopecia
74
Technique for placing ventriculoatrial shunt?
1. Incision at anterior border of sternomastoid muscle to identify jugular vein
2. Tie off vein distally
3. Small opening to pass shunt down juvular vein into right atrium (biphasic P wave)
4. intraop fluoroscopy to confirm catheter is at T6 level
75
Technique for placing ventriculopleural shunt?
1. Incision between second and third rib lateral to midclavicular plane
2. insert tube after puncture of parietal pleura
76
What bones form the hard palate?
Maximall anteriorly
| Palatine posteriorly
77
What veins connected at the torcula?
```
(Confluence of sinus)
Superior sagittal
Transverse sinus
Straight sinus
Occipital sinus
```
78
What bones form the zygomatic arch?
Anterior (Zygoma)
| Posterior (Temporal - squamosal part)
79
What bones form the nasal septum?
Ethmoid (perpendicular plate) and vomer
80
What bones form the clivus?
Sphenoid and occipital bone
81
What nerve carries parasympathetic innervation to parotid gland?
Auriculotemporal nerve (part of mandibular nerve)
82
Which cerebellar peduncle carries only afferent fibers?
Middle cerebellar peduncle
83
Which thalamic vein join the thalamostriate vein?
None!
| Thalamostriate joins the internal cerebral vein of galen
84
Superior orbital fissure provides communication between which 2 areas?
Orbit and middle fossa
85
Lamina terminalis extends upward from optic chiasm and blends into what?
Rostrum of corpus callosum
86
What cistern is contained in posterior incisural space?
Quadrigeminal cistern
87
Lateral and medial posterior choroidal arteries are branches of which circle of willis artery?
PCA
88
How is CSF secreted from choroid plexus enters subarachnoid space?
Ventricular foramina of Magendie and Luschka
89
Rate of CSF formation
0.5L per day (0.33mL per minute)
90
Normal diameter of supraclinoid ICA
4-5mm
91
Where does basal vein originate and through which cistern does it pass?
Anterior perforated substance -> crural and ambient cisterns -> quadrigeminal cistern -> internal cerebral vein
92
Most medial structure in cavernous sinus?
ICA
93
Most common side effect of mannitol
Renal failure
94
When do majority of perioperative MI occur
POD3 and 5
95
Best method to assess cerebral metabolism
PET
96
Why are inhalational anesthetics called "uncoupling" agents?
Decrease cerebral metabolism but increase cerebral flow through vasodilation.
97
When should you reconsider use of nimodipine in vasospasm?
Diminished cardiac contractility (negative inotrope)
98
Elective craniotomy for meningioma who is hyponatremic and hypotension - what should you consider?
Adrenal insufficiency
99
What types of coagulopathies are not detected by PT/PTT/INR and platelet counts?
Dysfibrinogenemia, vWF disease, Factor XIII deficiency, ASA/Plavix use
100
Disorders with platelet sequestration
Hypersplenism with cirrhosis
Gaucher
Sarcoidosis
101
Who has increased risk of GI hemorrhage with steroid use?
Preexisting ulcer disease
102
O2 transport is maximal in what hematocrit range?
30-32%
103
What on CT is predictive for success of 3rd ventriculostomy for hydrocephalus
Triventricular hydrocephalus (obstructive) from aqueductal stenosis or blockage of 3rd ventricular outflow
104
Morphology of cerebral aneurysms
Saccular, dissecting and fusiform. Influences surgical and endovascular treatment
105
Most common cause of SAH
Head trauma
106
Most common cause of CSF leakage
```
Head trauma (skull fracture doubles risk)
Leaks to nose (rhinorrhea), ear (otorrhea), or orbit (mimics tears)
```
107
CSF nasal drainage vs secretion?
Glucose level (in CSF but not nasal drainage)
Double-ring "halo" sign on bed sheets or clothing
Confirm with beta-2 transferrin test
108
Best initial treatment for CSF leak
Bed rest and head elevation.
| If persists for 3 days, lumbar drainage
109
Major cause of spontaneous intracranial hypotension
Spontaneous CSF leaks
| Look for diffuse pachymeningeal enhancement on MIR
110
Areas most prone to DAI after head trauma
Corpus callosum and superior cerebellar peduncle
111
Microscopic hallmark of DAI
Axonal retraction balls (eosinophilic globular swellings at proximal/distal sites of disrupted axons)
112
Bullet wound: entrance or exit wound larger?
Entrance typically smaller
113
What radiologic view to fully appreciate occipital bone fracture
Towne view (mandible)
114
Which allele predisposes one to greater risk of Alzheimer after head injury
Apo E4
115
Area of intracranial facial nerve most commonly damaged by blunt trauma
Facial nerve around geniculate ganglion
116
Schirmer test
```
Distinguish facial nerve injury proximal/distal to geniculate ganglion.
Assess lacrimation (proximal = dry eye; distal = not interfere)
```
117
What type of temporal bone fractures most frequently results in external manifestations (otorrhea, tympanic membrane rupture)?
Longitudinal fractures
| Transverse spares middle ear, tympanic membrane and external auditory canal (fewer signs)
118
Why EEG ordered in lowered levels of consciousness posttrauma?
R/O subclinical status epilepticus
119
Range of cerebral perfusion pressure accommodated by cerebral autoregulation
60-160mmHg
120
Calculation for cerebral perfusion pressure?
Mean arterial pressure - intracranial pressure
121
CPP should be maintained above what after severe head injury?
70 mmHg
122
Calculating MAP?
1/3SBP+2/3DBP
123
At what blood flow rate does electrical activity of cerebral cortex fail?
20 mL/100g /min
124
Brainstem reflexes mandatory to test in brain death evaluation
Pupils, corneal, oculovestibular, oculocephalic, gag.
Response to deep central pain and apnea test
No evidence of drug or metabolic intoxication
125
Auditory evoked potentials in evaluating brain death, what weight is necessary for the test to be valid?
Wave I, at least on one side
126
Neuroprotective medications
Corticosteroids, calcium channel blockers, glutamate antagonist, Manitoba, barbiturates
127
Trauma patient with broken leg deteriorates after manipulation of broken leg on hospital day five. Most likely cause?
Fat emboli syndrome
128
Why bifrontal exposure for persistent rhinorrhea after trauma?
Fracture of anterior fossa often extends across midline
129
Prophylactic antibiotics for CSF leaks after traumatic brain injury?
Not recommended according to Lancet 1994 article. Encourage resistance and late attacks of meningitis
130
Use of hyperventilation and head injury?
No good random my studies to support for use. May decrease cerebral perfusion pressure and delivery of oxygen and glucose.
131
Young adult with family history of migraines present with head trauma and blindness
Trauma triggered migraine with transient cortical blindness
132
How can acute SDH appear ice so intense to brain in multi-trauma patient?
Hematocrit less than 23
| Coagulopathy
133
Why EDH more common in younger adults?
Dura is thinner and more adherent to the skull in elderly
134
EDH in children versus adults
Children: caused by venous bleeding more
Adult: middle meningeal artery
135
Common drug to suppress cerebral metabolism in setting of major cerebral trauma
Barbiturates
136
Typical dosage of pentobarbital for suppression of cerebral metabolism and setting of major cerebral trauma
Loading dose of 10 mg/kg over 30 minutes, then 5 mg/kg per hour over three hours
137
Where on carotid artery is the most common location for a traumatic aneurysm?
Between proximal and distal dural rings. Pseudoaneurysms that may project medially into sphenoid sinus.
138
Shortcomings of GCS
Eye-opening in periorbital trauma, verbal response and intubated patient, brainstem functions or reflexes
139
Association between mean your skull fracture on radiograph and risk of intracranial hematoma
Increase risk by 400 fold
140
Early versus late posttraumatic seizure
Early: first seven days. Prophylactic phenytoin therapy to prevent early posttraumatic seizures
Late: after seven days. No proven advantage to prevent late seizures
141
Preferred method of intubation in patients with basal skull fracture
Orotracheal intubation. Possibility of entering cranium through cribriform plate with nasotracheal intubation.
142
Prerequisites for growing skull fracture
1. Fracture occurs in infancy or early childhood
2. Dural tear at time of fracture
3. Brain injury at time of fracture with displacement up leptomeninges
4. Subsequent enlargement of fracture to form cranial defect
143
Fall in end tital CO2 could be the only clue to what?
Air embolus
144
Treatment of air embolism
Lower patients head, rotate patients left side downward, aspirate from venous line in right atrium, and eventually patient while maintaining blood pressure and heart rate
145
Cases where hyperemia of brain occurs?
Head trauma, after carotid endarterectomy/stenting, excision of AVM
146
How to confirm diagnosis of DIC?
Low platelet count, prolonged PT, elevated fibrin degradation products, reduced fibrinogen levels
147
Treatment of cluster headaches
Oxygen, sumatriptan
148
Best drug for immediate control of seizures and status epilepticus
Lorazepam, better than diazepam are phenytoin
149
Signs and symptoms of myxedema coma
Emergency of hypothyroidism: hypotension, bradycardia, hyponatremia, hypoglycemia, hypothermia, hypoventilation
150
Treatment of myxedema coma
IV fluids, intubation if necessary, IV glucose
400 MG hydrocortisone IV over 24 hours, 0.5 MG levothyroxine IV followed by 0.05 levothyroxine per day
151
Three places a shunt maybe occluded
1. Entry point (proximal occlusion)
2. Valve system (valve obstruction)
3. Distal and (distal catheter occlusion)
CT head, shunt series, palpation about
152
Patient with history of pituitary trauma presents with sudden onset headache and rapid visual failure with extra ocular nerve palsy. Most likely diagnosis
Pituitary apoplexy, can mimic SAH. Treatment is urgent steroids
153
Management of life-threatening cerebellar swelling from infarction
Reception up cerebellar infarction maybe needed
| Ventriculostomy as temporizing measure in anticipation of surgery
154
Drugs used in NMS
Bromocriptine and dantrolene
155
Most common cerebrovascular comp patient during pregnancy
SAH
Risk of rupture parallels hemodynamic changes with blood volume change; most prone to rupture during seventh and eight months of pregnancy
156
Most common site of hypertensive cerebral hemorrhage?
Putamen
157
Addisonian crisis: signs and symptoms
Atrial insufficiency emergency: mental status changes, muscle weakness, postural hypotension, shock, hyponatremia, hyperkalemia, hypoglycemia, hyperthermia
158
Addisonian crisis: treatment
100 MG IV hydrocortisone immediately and then 50 MG IV Q6 hours
159
Central pontine myelinolysis
Rapid correction of hyponatremia causing disorder of punching white matter; insidious flaccid quadriplegia and mental status changes.
Sodium should not be corrected faster than 10 mEq per liter/24h
160
Neurogenic pulmonary edema
Associated with SAH, head trauma, seizure
| Increased capillary permeability and lungs associated with increased sympathetic discharge.
161
Neurogenic pulmonary edema: treatment
Reduce ICP, maintain positive pressure ventilation, supportive care
162
Treatment of acute migraine attack
Compazine/prochlorperazine 10 MG IV
163
What potential emergency can occur intracranial late if nitrous oxide anesthesia is not discontinued prior to closure of director in surgery?
Tension pneumocephalus
164
Most common complication of trans oral operative route?
CSF leakage and infection
165
Cystic tumor of suprasellar region that arises from neuroectodermal remnants of Rathke pouch
Craniopharyngioma
166
Preop medications to lessen risk of patients with growth hormone secreting tumor
Somatostatin analog
167
Lesion with calcification in cellar area and erode through posterior clinoid
Craniopharyngioma. Erosion of posterior clinoid may also occur from chronic increase in ICP
168
Tumor that can erode internal acoustic meatus
Acoustic schwannoma
169
Tumor that can erode petrous apex
Trigeminal schwannoma
170
Tumor that can erode clivus
Chordoma
171
Tumor that can erode sellar floor
Large pituitary tumor
172
Tumor that can erode orbital foramen
Optic nerve glioma
173
Tumor that can erode jugular foramen (the bone)
Glomus jugulare
174
What disease may produce generalizable erosion? and hyperostosis?
Multiple myeloma, paget disease
| Meningioma results in focal hyperostosis
175
Most common extradural neoplasm involving the clivus
Chordoma (typical, and chondroid - better prognosis)
176
IHC of chordoma versus chordosarcoma
Chordoma always things positive for keratin with S 100.
| Chordosarcoma lacks epithelial markers but always positive for S 100
177
Malignant potential of chordoma
Critical location, locally aggressive nature, hybrid of recurrence, occasional tendency to metastasize
Histologically benign
178
Most common site of origin of chordoma
Sacrum
179
Second most common site of chordoma
Clivus
180
Prophylactic cranial irradiation may be considered for what patients
Small cell lung cancer
181
What lesion most commonly removed by endoscopic methods
Colloid cyst
182
Where are colloid cyst found?
Anterior roof of third ventricle
183
How do colloid cyst cause death?
Obstructive hydrocephalus
184
Most common in intraorbital tumor in adults
Cavernous hemangioma: benign, slow-growing vascular lesion
| Painless, progressively proptotic eye
185
Second most common type of intracranial schwannoma
Trigeminal schwannoma
| Vestibular type most common
186
Most common presentation of choroid plexus tumor?
Intracranial hypertension
187
Location of choroid plexus papilloma between adults and children
Children: left lateral ventricle
Adults: fourth ventricles
Rare benign tumors of CMS, male predominance
