9. Neurosurgery

Question 1

What is the best at detecting VAE

Answer 1

Precordial Doppler - best non invasively

Question 2

Options for VAR detection

Answer 2

Precordial Doppler is the most sensitive non-
invasive monitor, simple and able to detect as little
as 0.015 mL/ kg/ min of intracardiac air.

Precordial stethoscope requires a large amount of air to
be entrained before detection of the classic millwheel murmur. End- tidal CO
2 is not specific to air
embolism.

Transoesophageal monitors are more sensitive than precordial Doppler but are invasive, expensive, and can be associated with complications such as oesophageal injury.

Question 3

23- year- old man with complete transection of his spinal cord at T1 following an accident five months ago presents for a cystoscopy and urethral dilatation.

He is known to have muscle spasms and has had one
previous episode of autonomic dysreflexia.

His body mass index (BMI) is
38. Which of the following would be the most appropriate anaesthetic
technique?
A. No anaesthesia is required
B. Lumbar epidural
C. Low- dose spinal
D. General anaesthesia with LMA
E. Sedation with midazolam

Answer 3

C. Low- dose spinal

Question 4

Anaesthetic options in cord transections with ADR

Answer 4

If site of surgery is below the level of the lesion and is complete no anaesthesia may be required
unless the patient suffers from muscle spasms or autonomic dysreflexia (ADR). That is therefore
not appropriate in this case.

Spinal anaesthesia is safe and is an effective way to abolish muscle spasms and ADR.

Epidurals may be unreliable for general or urological procedures.

Sedation does not reliably abolish muscle spasms or
ADR.

A general anaesthetic would be an acceptable technique but intubation would be preferable as this
patient has a high thoracic lesion and would have paralysis of his intercostal and abdominal wall
muscles. He would be prone to hypoventilation and have reduced lung compliance. He would also
be more at risk of aspiration as he has a high BMI and slower gastric emptying

Question 5

A 24- year-
old man presents to the emergency department following a fall with a head injury.

There are no obvious extracranial injuries.
His Glasgow Coma Scale (GCS) is 6/
15.
You intubate him with manual
in-line stabilization of his cervical spine. What is the most important
management step to prevent secondary injury?
A. Maintain a mean arterial pressure (MAP) >80–
90 mmHg
B. Maintain a PaCO 2 of 4.0– 4.5 kPA
C. Aim for a blood glucose of 6–10 mmol
D. Actively cool the patient to 35°C
E. Maintain a PaO2 >20 kPa

Answer 5

A. Maintain a mean arterial pressure (MAP) >80–

90 mmHg

Question 6

Secondary brain injury targets

Answer 6

The main targets to avoid secondary brain injury are intubation and ventilation of anyone with a GCS <8. Then aim for PaO 2 >13 kPa,
PaCO2 4.5–5 kPa,
a MAP >80– 90 mmHg,
and normoglycaemia.

Hyperthermia should also be avoided.

The most important of these are blood pressure control and maintaining oxygenation.

Episodes of hypotension or hypoxia are associated with a poorer outcome

Question 7

4. A 26-year-old female presents
   with subarachnoid haemorrhage (SAH).

She has no significant past medical history. On your arrival her eyes are open spontaneously,
speech is confused,
and she is localizing to pain
on the right side only.

Pupils are equal and reactive. What is the most
appropriate clinical severity grade attributed?
A. Grade 1
B. Grade 2
C. Grade 3
D. Grade 4
E. Grade 5

Answer 7

C

Question 8

Grading systems for SAH

Answer 8

There are more than 40 grading systems that can be used to describe the severity of SAH.

A frequently used scale based on clinical signs is the World Federation of Neurosurgeons Scale

(WFNS) and is graded 1–5 based on GCS and motor deficit.
It is related to prognosis.

This patient has a GCS of E4, M5, V4 (total 13/15)
with a hemiparetic motor deficit evident.

Clinically based scales are subject to interprofessional variability on assessment but do provide a
means of summarized communication between team members and the regional neurological centre

Question 9

Severity of SAH grading
Grade
WFNS description

Answer 9

Severity of SAH grading
Grade
WFNS description
1 GCS 15, no motor deficit

2 GCS 13–14, no motor deficit

3 GCS 13–14 with motor deficit

4 GCS 7–12, with or without motor deficit

5 GCS 3– 6, with or without motor deficit

Question 10

5. You are anaesthetizing a patient who is receiving posterior fossa surgery in the prone position.
   Their head is in a three- pin clamp.

There is a sudden cardiovascular collapse proceeding immediately to cardiac arrest. The correct sequence of actions is:
A. Remain prone, clamp remains, commence posterior compressions
B. Remain prone, commence posterior compressions, release head from clamp
C. Remain prone, release head from clamp, commence posterior compressions
D. Release head clamp, leave pins
in situ, turn supine and commence compressions
E. Remove all pins, turn patient supine, commence compressions

Answer 10

B. Remain prone, commence posterior compressions, release head from clamp

Question 11

CPR in head clamp pins proned

Answer 11

Cardiopulmonary resuscitation (CPR) should not be delayed and there is no immediate need
to turn the patient to the supine position; 

CPR should be started with the patient in the prone
position.

The head can be released from the clamp on the operating table rather than trying to release the head from the pins.

This reduces the risk of injuring the scalp, leaving a bleeding pin- hole, or the operator being injured by the pins.

The surgeon can support the patient’s head while
CPR is administered

Question 12

6. You are taking a 64-
   year-old man with learning difficulties for magnetic
   resonance imaging (MRI) of the brain under anaesthesia.
   The presence of which of the following would be a contraindication to this procedure?
   A. Prosthetic hip replacement
   B. Sternotomy wires for previous coronary artery bypass graft (CABG)
   C. Cochlear implant
   D. Plate in wrist from previous open reduction and internal fixation (ORIF)
   E. Metal heart valve

Answer 12

C. Cochlear implant

Question 13

Absolute contraindications to MRI include

Answer 13

1 cochlear implants,
2 intra- ocular foreign bodies,
3 ferromagnetic neurovascular clips.

Cardiac pacemakers and implantable defibrillators would also be contraindicated as these may malfunction within the 5 Gauss line.

Question 14

No C/I devices

Answer 14

Most modern prosthesis are non- ferromagnetic. General surgical clips, artificial heart valves, and sternal wires are usually deemed safe as they are fixed in place by fibrous tissue

Question 15

7.
A 28-year-old man has complete transection of this spinal cord at T4 following a road traffic accident 18 months ago.

He is coming to theatre for insertion of a Baclofen pump.
In theatre reception he complains of
headache and flushing and his blood pressure is
194/ 98 mmHg.
What would be the most appropriate initial step?
A. Re-check blood pressure
B. Perform an ECG
C. Exclude bladder obstruction
D. Give diazepam pre- medication
E. Take blood cultures

Answer 15

C. Exclude bladder obstruction

This is describing autonomic dysreflexia and the most important first step is to exclude urinary
obstruction before administration of drugs

Question 16

8. A 37- year-old woman suffered a SAH four days ago. She is a smoker with no past medical history of note. The aneurysm was secured with coiling.
   Her GCS is currently 15 and there is no neurological deficit.
   The most common cause of a delayed neurological deficit now
   is:
   A. Delayed cerebral ischaemia
   B. Hydrocephalus
   C. Seizure
   D. Re- bleeding
   E. Cerebral
   oedema

Answer 16

A. Delayed cerebral ischaemia

Question 17

Complications of SAH

Risk Rebleeding highs when

Hydrocephalus

Seizures

Answer 17

Those with poor clinical grade SAH and/ or large amounts of subarachnoid and intraventricular
blood are at particularly high risk of complications.

The risk of re-bleeding is greatest immediately after the initial haemorrhage, with rates of 5–10%
within the first three days.

Twenty to 30% of patients develop hydrocephalus, usually within the first three days but it may also be delayed.

Clinical seizures are uncommon, occurring in only 1–7% of patients. In patients with an unsecured aneurysm, they are often a sign of a re- bleed.

Although seizures should be treated aggressively,
the use of prophylactic anticonvulsants is associated with a worse outcome after SAH and is not recommended.

Delayed cerebral ischaemia occurs in >60% with the greatest risk between days 4 and 10 and
may even occur in the absence of vasospasm.

Smokers are particularly at risk for vasospasm. This
patient is a smoker starting at day 4 post bleed

Question 18

A 42- year-old man presents for transsphenoidal excision of pituitary adenoma.

He originally presented with refractory hypertension,
diabetes, and central obesity.
The most likely endocrine abnormality is:

A. Hyperprolactinaemia
B. Antidiuretic hormone (ADH) hyposecretion
C. Thyroid stimulating hormone (TSH) hypersecretion
D. Adrenocorticotropic hormone (ACTH) hypersecretion
E. Growth hormone hypersecretion

Answer 18

D. Adrenocorticotropic hormone (ACTH) hypersecretion

Question 19

Cushings

D/T

Rx for Adenoma

Typical habitus

Answer 19

This patient presents with features of Cushing’s disease.

This is an excess of glucocorticoid due to hypersecretion of ACTH from a pituitary corticotrophin adenoma,
the term Cushing’s syndrome being applied to a non- specific state of chronic glucocorticoid excess regardless of cause.

Surgical excision is the definitive management,
but medical treatment may reverse much of the effects of excess glucocorticoid and considerably reduces perioperative risk.

The typical habitus of Cushing’s syndrome is one of truncal obesity, moon face and thin extremities.

Glucose intolerance is seen in almost two-thirds of patients with Cushing’s disease, half of whom will have frank diabetes

Question 20

You assess a 46-year-old woman for percutaneous endoscopic gastrostomy (PEG) tube insertion. She has a six-month progressive neurological condition with chorea, dystonia, and pyramidal signs.

She is suspected to have variant Creutzfeldt–
Jakob disease.
The most appropriate advice is:
A. No risk from routine contact, no isolation, disposable airway equipment, disposable
surgical endoscope
B. No risk from routine contact, no isolation, disposable airway equipment, reusable surgical
endoscope
C. Barrier nursing, isolation, disposable airway equipment, disposable surgical endoscope
D. Barrier nursing, isolation, disposable airway equipment, reusable surgical endoscope
E. No risk from routine contact, no isolation, reusable airway equipment, reusable surgical
endoscope

Answer 20

A. No risk from routine contact, no isolation, disposable airway equipment, disposable
surgical endoscope

Question 21

Prion proteins and removal

Cleaning and destruction

Answer 21

Abnormal prion protein is not completely removed by conventional sterilization methods, including
autoclaving. This poses problems for transmission of prion disease by contaminated surgical
equipment. This is relevant when a patient with CJD, or at increased risk of CJD, has a procedure
involving tissue which is deemed of medium or high
risk.

With the advent of CJD, there has been a need for airway equipment to become single use. In most
centres, disposable laryngoscope blades and single-
use laryngeal masks are now in routine use.

While fibreoptic intubating endoscopes have until recently been sterilized and reused, disposable
endoscopes are now available.

Anaesthetizing a patient with suspected CJD is essentially similar to routine practice with no particular barrier measures, routine contact infection risk, or isolation required.

In this case, the gastrointestinal lymphoid tissue is of medium infectivity risk so the surgical scope should be incinerated

Question 22

11.
A 72- year- old woman with a one- year history of myasthenia gravis presents for wide local excision of breast cancer. She has no other significant past medical history.

Her medication includes Pyridostigmine 90 mg three times per day.

Preoperative investigation revealed a forced vital capacity (FVC) of 4.2 L, and normal echocardiography and ECG.

She is of average height and normal BMI. She is able to manage one flight of stairs. She has no swallowing problems. There is no ITU bed currently available. What is the best
plan?

A. Postpone surgery until ITU bed availability
B. Proceed with spontaneous breathing technique on laryngeal mask airway (LMA), High
Dependency Unit (HDU) postoperatively
C. Intubate with an opiate based technique avoiding muscle relaxants, HDU postoperatively
D. Give suxamethonium, intubate, HDU postoperatively
E. Give non- depolarizing muscle relaxant, intubate, HDU postoperatively

Answer 22

B. Proceed with spontaneous breathing technique on laryngeal mask airway (LMA), High
Dependency Unit (HDU) postoperatively

Question 23

12.
Which of the following operative positions is best avoided in routine
posterior fossa neurosurgery?
A. Trendelenburg
B. Supine
C. Prone
D. Park
bench
E. Lateral

Answer 23

A. Trendelenburg

Question 24

Posterior fossa surgery positions

best avoided

Answer 24

12. A
    Posterior fossa surgery is commonly performed in supine, prone, sitting, lateral, and park bench
    positions.

The Trendelenburg position would lead to increased venous engorgement although may be used in an emergency,
when air embolism is suspected, to place the surgical field below the level of the heart.

Park bench position is a modification of the lateral position where the patient is positioned semi-prone with the head flexed and facing the
floor. This facilitates greater access to
midline structures and, in selected patients, avoids the need for the prone position

Question 25

Posterior fossa surgery positions

best avoided

Answer 25

12. A
    Posterior fossa surgery is commonly performed in supine, prone, sitting, lateral, and park bench
    positions.

The Trendelenburg position would lead to increased venous engorgement although may be used in an emergency,
when air embolism is suspected, to place the surgical field below the level of the heart.

Park bench position is a modification of the lateral position where the patient is positioned semi-prone with the head flexed and facing the
floor. This facilitates greater access to
midline structures and, in selected patients, avoids the need for the prone position

Question 26

13.
A 22-year old man has suffered a diffuse axonal injury following car crash. He has spinal immobilization in place in ITU.
GCS is 6 despite removal of sedation. Spinal fixation is
in situ
. What is the most appropriate course of action regarding spinal immobilization?

A. Computerized tomography (CT) neck, remove collar if normal
B. CT neck, collar remains if normal
C. Await improvement in GCS
D. MRI neck, remove collar if normal
E. MRI neck, collar remains if
normal

Answer 26

A

Question 27

How to remove c spine collar

Answer 27

13.A

The question describes a patient with a poor prognosis who is likely to remain low GCS for an
unknown period of time.

‘Clearing’ the cervical spine requires an awake cooperative patient.

However prolonged, unnecessary spinal immobilization also represents significant risks to the patient.

Clinicians must decide what investigation, or combination of investigations, provides them
with enough evidence to either diagnose a cervical spine injury or exclude it.

MRI in the trauma ICU patient presents monitoring/
transfer/access difficulties.

High-resolution CT should provide satisfactory images with 3D reconstruction.

If these images are reported as normal, by an experienced radiologist, then the risk of the patient having a significant, missed injury is small enough to warrant safe removal of spinal immobilization

Question 28

14.
You anaesthetize a patient with well controlled epilepsy for elective inguinal hernia repair. They had taken their usual antiepileptic medication while fasting. In recovery they have a self-
terminating tonic– clonic seizure. The correct advice
is:
A. Driving not affected
B. No driving for at least three
months
C. No driving for at least six
months
D. No driving for at least nine
months
E No driving for at least 12 months

Answer 28

E. No driving for 12 months.

Question 29

Driving rules around epilepsy and seizures

Answer 29

No driving for 12 months.
If seizures have occurred while awake and conscious the driving licence is taken away for at least
12 months.

The patient can reapply if they have been seizure free following this time

If the seizure occurred because a doctor changed or reduced the anti-epilepsy medicine, they can
reapply after six months free of seizures.

If the patient has a bus/coach/ lorry license the rules are
much stricter with five years seizure free required

Question 30

15. You are asked to provide an anaesthetic opinion for a patient being considered for awake craniotomy. Which of the following is an absolute
contraindication for awake craniotomy?
A. Obstructive sleep
apnoea
B. Learning difficulties
C. Patient anxiety
D. Language barrier
E. Inability to lie still

Answer 30

E. Inability to lie still

Question 31

Contraindications for Awake craniotomy

Relative contraindications

Answer 31

A patient who is unable to lie still for the duration of the operation is an absolute contraindication
for awake craniotomy. Clearly this may be due to a variety of causes— physical or psychological.

All the other answers are relative contraindications.
Awake craniotomy is an important technique for increased lesion removal and minimizing
damage to eloquent cortex.

An important aspect of an awake craniotomy is the patient selection and preparation by the multidisciplinary team.

The patient must know what to expect and the
anaesthetic risks involved

Question 32

16. EEG- based depth of anaesthesia monitors have been used in an attempt to reduce awareness during general anaesthesia. Depth of anaesthesia
    monitoring should be used:
    A. When thiopental is used as the induction agent for general anaesthesia
    B. During general anaesthesia for cardiac surgery
    C. During total intravenous anaesthesia (TIVA) with neuromuscular block
    D. During caesarean section under general anaesthesia
    E. During all general anaesthesia

Answer 32

C.
During total intravenous anaesthesia (TIVA) with neuromuscular
block

Depth of anaesthesia monitoring is recommended during TIVA. The other answers include risk
factors for awareness.

Question 33

17. A patient is undergoing posterior fossa surgery for an acoustic neuroma.
    The anaesthetic induction was uneventful and the patient is haemodynamically stable.

Half an hour into the operation, you
notice a sudden reduction in end- tidal CO2
waveform with a drop in blood pressure from 115/65 mmHg to 78/42 mmHg.

What is the most immediate action to take next?
A. Aspirate air from the central venous catheter
B. Administer metaraminol bolus
C. Ask the surgeon to flood the operative field with
fluid
D. Increase FiO 2 to 1.0
E. Give adrenaline (epinephrine) 0.1 mg IV
bolus

Answer 33

C. Ask the surgeon to flood the operative field with

fluid

Question 34

Mx of VAE important steps

Answer 34

The most likely cause of this scenario is air embolism due to an open vessel in the surgical field
therefore flooding the site with saline will prevent further in- drawing of air.

Air embolism is a rare but serious consequence of intracranial surgery.

During acoustic neuroma surgery it can happen if the sigmoid sinus or jugular venous sinus are breached.

The patient is usually head up for this procedure and air intake is minimized by having the surgeon immediately
flood the surgical field, cover it, and tilt the patient head
down.

Increasing the FiO2 (D), and using vasopressors (B and E) are supportive measures which may also
be required.

Aspirating air from the CVP line (A) is impractical, unlikely to be effective, and risks exposing the circulation to further air.

Auscultation of the chest typically reveals a mill wheel murmur which helps confirm the diagnosis

Question 35

18. A 42- year-old woman presents to the Emergency Department complaining of new onset pins and needles in both legs.

They are not painful but she feels they are becoming weak.

On examination, power is 4/5 bilaterally and the patellar and Achilles tendon reflexes are absent.
Lower limb pulses are present and normal.

Colour is normal with no muscle wasting or skin changes.

What is the most likely diagnosis?
A. Diabetic neuropathy
B. Vascular insufficiency
C. Multiple sclerosis
D. Guillain– Barré syndrome
E. Myasthenia gravis

Answer 35

D. Guillain– Barré syndrome

Question 36

Neurological disease characteristic features

GBS

MND

MS

MG

Answer 36

Guillain–Barré disease is an ascending symmetrical polyneuropathy affecting somatic and autonomic
nerves.

It is characterized by motor weakness but sensory changes also occur.

A and B would be painful conditions with normal power and associated skin changes such as ulceration or venous congestion.

Motor neurone disease has no sensory component.

Multiple sclerosis affects random areas of the body and is not symmetrical.

Myasthenia gravis has brisk tendon reflexes and weakness characterized by fatigability.

Question 37

19. A 47- year- old woman is referred to the pain clinic by the neurosurgeons.

She has low back pain and radiating down to her ankle on the left. 
MRI scan shows bulging discs at L4,5 and L5,S. She is reluctant to proceed with surgical options at present. What is the best option to facilitate
non-surgical management of this patient?
A. Regular acupuncture
B. Caudal epidural steroid injections
C. Facet joint injections
D. Titrate opioid analgesia as required
E. Refer to pain management programme

Answer 37

E. Refer to pain management programme

Question 38

Pain management in back pain

Answer 38

Self-management is the key to long-
term success in pain management, giving the patient an internal locus of control, tools, information, and support to deal with chronic pain and flare ups.

Long- term management will require pacing, setting objectives, and practising mindfulness or relaxation.

Regular acupuncture works for some patients but is not a long- term solution nor is it recommended
for low back pain (NICE CG59).

Caudal steroid injections will help the pain but only in the short term.

It is not practical to repeat these at frequent intervals. Facet joint injections will not help the
pain which is most likely due to disc impingement or compression of nerves or disc pathology
causing inflammation around nerve roots.

Opioids are not recommended as a long-
term solution in back pain. They can be used with care, for short periods with defined objectives agreed with patient

Question 39

20. A 37- year- old man is admitted to ITU following a high- speed road traffic accident.

He has undergone an emergency laparotomy for liver
laceration.

A postoperative CT scan of his head showed a possible small haematoma.

In ITU his renal function is deteriorating and his platelet count is falling.

You are called to urgently review him when the nurse
notices his right pupil to be newly fixed and dilated when performing neuro observations. What is the most appropriate action to take next?

A. Arrange an urgent repeat CT head
B. Arrange transfer to the nearest neurosurgical
unit
C. Speak to haematology about giving pooled platelets
D. Insert an arterial line
E. Prescribe intravenous mannitol 0.5 g/kg

Answer 39

E IV mannitol 0.5 g/kg

Question 40

Management of a unilateral fixed dilated pupil post head injury…

Answer 40

A unilateral fixed dilated pupil after head injury indicates imminent herniation and must be
decompressed immediately. This can be achieved with a bolus dose of mannitol 0.5 g/ kg.

Mannitol is an osmotic diuretic which draws fluid from neurons reducing intracranial volume and
pressure for a short period to allow preparation for urgent craniotomy.

The acute problem is not due to a bleeding diathesis so treatment with clotting products is not appropriate.

There is no time to repeat the CT of head. The diagnosis of raised intracranial pressure is a
clinical one in this scenario. Likewise, inserting an arterial line may be useful but will not prevent
deterioration of the patient’s clinical condition.