neurosurg

Question 1

Communicating hydrocephalus

Answer 1

All ventricles affected. Due to defect in absorption at the arachnoid granulations

Question 2

Noncommunicating hydrocephalus

Answer 2

Obstructive; due to block in CSF proximal to arachnoid granulations. May not affect all ventricles dep on level of block (e.g. aqueductal stenosis spares the 4th ventricle)

Question 3

Third type of hydrocephalus

Answer 3

ex vacuo

Question 4

Indications for carotid endartectomy

Answer 4

Asymptomatic: > 70% Symptomatic: > 60% NB: pts should stay on aspirin leading up to the surgery. If post-CVA, wait 4-6 wks for procedure

Question 5

Carotid dissection causes

Answer 5

Trauma, CT disease, iatrogenic (angiogram), vasculitis

Question 6

Carotid dissection symptoms

Answer 6

May have neck pain, headache, ipsilateral Horner syndrome, sx of SAH or stroke; can be nonspecific.

Question 7

Carotid dissection management

Answer 7

If extradural, use medical therapy (anticoagulation). If intradural, do endovascular stenting or surgical bypass of ECA to ICA. Follow for 3-6 mo for healing.

Question 8

Carotid dissection epidemiology

Answer 8

Carotid artery dissection is a significant cause of ischemic stroke in all age groups, but it occurs most frequently in the 5th decade of life and accounts for a much larger percentage of strokes in young patients.

Question 9

Carotid dissection pathophys

Answer 9

Begins as a tear in one of the carotid arteries of the neck, which allows blood under arterial pressure to enter the wall of the artery and split its layers. The result is either an intramural hematoma or an aneurysmal dilatation, either of which can be a source of microemboli, with the latter also causing a mass effect on surrounding structures.

Question 10

Uncal herniation

Answer 10

CN 3 palsy (blown pupil, down and out). Hemiparesis: can cause contralateral (from ipsilateral peduncle pressure) or ipsilateral (from contralateral peduncle pressure due to midbrain shift, aka Kernohan’s phenomenon)

Question 11

Herniation syndromes

Answer 11

Cingulate (subfalcine) can affect ACA -> abulia. Cerebellar (upward) can occlude superior cerebellar arteries -> ataxia. Tonsillar can be rapidly fatal. CEntral (transtentorial) causes decreased consciousness, occlusion of PCAs leading to cortical blindness, Cheyne-Stokes etc

Question 12

Parinaud syndrome

Answer 12

Parinaud’s Syndrome, aka dorsal midbrain syndrome and vertical gaze palsy, is an inability to move the eyes up. It is caused by a tumor of the pineal gland which compresses the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF). The eyes lose the ability to move upward.

Question 13

Low-grade astrocytoma

Answer 13

Cerebral hemispheres or cerebellum. Asx lesions should be followed. Surgery usu not curative but used if sx. Radiotherapy used. Chemo if surgery/rads fail

Question 14

Malignant glioma includes..

Answer 14

Anaplastic astrocytoma, glioblastoma multiforme

Question 15

Glioblastoma multiforme

Answer 15

Have necrotic center, enhancing rim. Very poor prognosis (pretty much 0% 5 yr survival) despite surgery and radiation. Chemo does not help

Question 16

Meningioma

Answer 16

F > M. Arise from arachnoid region. Seen on superior convexities, orbital rim, cerebellar tentorium, intraventricular. Slowly progressive growth. Homogeneous enhancement on MRI/CT, may have dural tail. Tx: surgical resection if sx. If can’t resect, do external beam radiotherapy/gamma knife. 5 yr survival 90%, often recur.

Question 17

How to treat acromegaly from pituitary adenoma?

Answer 17

Surgical resection is curative 50% of time. Medical tx: octreotide (somatostatin analogue)

Question 18

How to treat TSH adenoma?

Answer 18

Octreotide

Question 19

How to treat prolactinoma?

Answer 19

Dopamine agonists first; surgical excision if no response to med tx

Question 20

How to treat Cushing syndrome from pituitary adenoma?

Answer 20

Surgery

Question 21

Neuromas most commonly affect what CN?

Answer 21

CN 8 (acoustic neuroma)

Question 22

Bilateral acoustic neuromas are pathognomic for what syndrome?

Answer 22

NF2

Question 23

Ependymoma

Answer 23

Most often in children, usu a posterior fossa mass. Tx: surgical resection; rads if in 4th ventricle or spinal cord.

Question 24

Oligodenroglioma

Answer 24

Predilection for frontal lobes. Histology: “fried egg” or “chicken wire” appearance. Slowly progressive; most often presents with seizure. Tx: surgery, post-op rad often, chemo somewhat helpful.

Question 25

Craniopharyngioma

Answer 25

Most often in childhood. Benign but difficult to cure. Presents with HA, visual disturbance.

Question 26

Pineal tumors

Answer 26

More often in children. Possibly can be germinoma or teratoma, so measure HCG and AFP; recall that germinomas are radiosensitive.

Question 27

CNS lymphoma

Answer 27

Tend to melt away after one round of steroids but will come back. Radiation therapy is mainstay of tx. MTX and CHOP chemo

Question 28

Epidermoid and dermoid tumors

Answer 28

Non-neoplastic masses, congenital or 2/2 trauma. Rare type of brain mass. Surgical excision if sx

Question 29

What is the most common pediatric malignant brain tumor?

Answer 29

Primitive neuroectodermal tumors (PNET). Located on cerebellar vermis. Tx: surgery followed by XRT

Question 30

Glomus tumors aka paraganglioma

Answer 30

Arise from paraganglion cells, rare. May secrete catecholamines. Location: carotid bulb, jugular glomus body. Can present similarly to acoustic neuromas but distinguish by angiogram: glomus tumors are highly vascular.

Question 31

What types of metastasis to the brain are radiosensitive?

Answer 31

SCLC, lymphoma, MM, germ cell tumors

Question 32

Tuberous sclerosis

Answer 32

Ash leaf spots. Supependymal hamartomas, calcific. Causes seizures

Question 33

Spurling’s sign

Answer 33

Cervical spine finding- radicular pain produced with downward pressure on head when neck extended and tilted toward affected side

Question 34

Herniated disc bulging vs protruding

Answer 34

Bulge is symmetric extension. Protrusion is asymmetric

Question 35

Atlantoaxial (C1 = atlas) dislocation

Answer 35

RA underlies 1/4 of cases. Presents with local pain +/- hyperreflexia. If sx or atlantodental interval >6 mm, do C1-C2 fusion.

Question 36

How to assess pathologic hyperreflexia vs benign normal variant?

Answer 36

In benign normal variant, jaw jerk reflex will also be hyperreflexic

Question 37

Thoracic outlet syndrome

Answer 37

Thoracic outlet is the space defined by the clavicle and 1st rib- subclavian artery/vein and brachial plexus pass through. Vascular compromise > neurologic compromise. PE: rotating head away from affected side + elevation of arm reproducing sx, +/- reduction of radial pulse. Etiologies: fibrous band, elongated C7 transverse process. Tx: surgical.

Question 38

Papilledema

Answer 38

see in CHRONIC increased ICP, not acute