nervous system

Question 1

Herniation syndromes - types

Answer 1

1. Cingulate (subfalcine) herniation under falx cerebri
2. Downward transtentorial (central) herniation
3. Uncal herniation
4. cererbellar tosilar herniation into the foramen

Question 2

Cingulate (subfalcine) herniation can cause

Answer 2

compression of anterior cerebral artery

Question 3

Downward transtentorial (central) herniation –> … (mechanism and complication)

Answer 3

caudal displacement of brain stem –> rupture of paramedian basilar artery branches –> duret hemorrhages –> usually fatal

Question 4

Duret haemorrhages are

Answer 4

small lineal areas of bleeding in the midbrain and upper pons of the brainstem.

Question 5

Uncal herniation - manifestations and mechanism

Answer 5

1. compress ipsilateral CN III (blown pupil, down-and-out gaze)
2. compress ispilateral PCA (contralateral homonymous hemianopia with macula sparing)
3. compress contralateral crus cerebri at tha Kernohan notch (ipsilateral paresis, a false localization sign)

Question 6

cererbellar tosilar herniation into the foramen magnum - manifestation and mechanism

Answer 6

coma and death result when these herniations compress the brain stem

Question 7

femoral nerve - functions

Answer 7

• leg flexion at the hip
• leg extension at the knee
• sensation to the anterior thighh and medial leg via saphenous branch

Question 8

common peroneal nerve - function

Answer 8

gives rise to superficial and deep peroneal nerves

• muscles of the anterior and lateral leg
• sensation to the anterolateral leg and dorsum of the foot

Question 9

obturator nerve - function

Answer 9

innervates the medial compartment of the thigh and controls adduction
senseation over the medial thight

Question 10

tibial nerve function

Answer 10

muscles of the posterior compartment of the thight, posterior compartment of the leg, plantar muscles of the foot

• flexion of the knee and digits, platnar flextion of the foot
• sensation to the leg (except medial side) + plantar foot

Question 11

4% of patients with spinal cord injuries will develop

Answer 11

post-traumatic syringomyelia –> impaired strength and pain pain/Q sensation in the upper extremities
(MRI is diagnostic) (MONTHS TO YEARS LATER)

Question 12

a potential complication of thoracic aortic aneurysm (and presentation)

Answer 12

anterior spinal cord infraction –> abrupt onset of bilateral FLACCID paralysis and loss of pain/Q sensation below the level of spinal injury)

• UMN signs develops over sevral days
• VIBRATION AND PROPIOCEPTION ARE PRESERVED

Question 13

acute shoulder pain after forecful abduction and external rotation at the glenohymeral joint suggests

Answer 13

anterior shoulder dislocation (which can cause injury to axillary nerve)

Question 14

hypoglossal nerve injury can cause ….

etiology

Answer 14

tongue palsy

sergery below te mandible such as for a tumor of the submandibular salivary gland

Question 15

epidural hematoma - pathogenesis

Answer 15

trauma to sphenoid bone with tearing of middle meningeal artery

Question 16

epidural hematoma - clinical features

Answer 16

1. brief loss of consciousness followed by lucid intercal
2. hematoma expansion leads to:
   - intracranial pressure
   - uncal herniation (ipsilateral CN 3 palsy and hemiparesis)

Question 17

epidural hematoma - diagnosis

Answer 17

Head CT: binconvex (lens shaped) hyperdensity that does not cross suture lines (no midline shift)

Question 18

epidural hematoma - treatment

Answer 18

urgent surgical evacuation for symptomatic patients

Question 19

diffuse axonal injury

Answer 19

results of traumatic acceleartion/deceleration shearing forces that diffusely damage axons in the brain
- coma, head ct: diffuse small bleeds at the grey-white matter junction

Question 20

Rotator cuff impingement or tendinopathy

Answer 20

pain with abduction, external rotation
subacrosomial tenderness
nroaml range of motion with positive impigement tests

Question 21

Rotator cuff tear

Answer 21

similar to rotator cuff tendinopathy

• weakness with abduction + external rotation
• older than 40

Question 22

Interventions for lowering ICP

Answer 22

1. head elevation
2. sedation (decreased metabolic demand + control hypertension)
3. IV mannitol
4. Hyperventilation (CO2 washout –> crebral vasoconstriction)
5. Removal of CSF (reduction of CSF volume pressure)

Question 23

common peronia nerve is aka …. / gives rise to

Answer 23

fibular nerve

- superficial + deep peroneal nerves

Question 24

superficial vs deep peroneal nerves regarding function

Answer 24

superficial: foot eversion, sense on medial and anterio leg

deep peroneal nerve: foot dorsiflexion, toe extension, sense between big and 2nd toes

Question 25

symptoms onset in subdural hematoma

Answer 25

gradually (1-2 days)

Question 26

Tic douloureux

Answer 26

aka trigmenial neuralgia: manifests with short burst of excruciating, lancinating pain lasting from seconds to minuts in the distribution of the 2nd and 3rd branches of the V neve (etiology: compression of V)