Neurosurgery and Neuroradiology Flashcards
A characteristic feature of postoperative visual loss due to posterior ischaemic optic
neuropathy is:
a) Painful
b) Normal light reflexes
c) Normal fundoscopy
d) Visual inattention
c) Normal fundoscopy
Following scoliosis surgery, a patient exhibits neurological changes in both legs. There is loss of power and reduced pain and temperature sensation. Proprioception and vibration sense are intact. The most likely mechanism of injury is:
a) Anterior spinal artery syndrome
b) Posterior spinal artery syndrome
c) Misplaced pedicle screw
STEPH a
The initial management for a seizure during an awake craniotomy is:
a. Cold saline irrigation
b. Midazolam
c. Propofol
Nikki
A) cold saline irrigation
Intraoperative seizures have a higher incidence of transient motor deterioration and longer hospital stays.[10] First-line treatment should be irrigation of the brain with sterile iced saline. Propofol bolus (10 to 20 mg IV) or midazolam (1 to 2 mg IV) should be administered to terminate the seizure if iced saline is ineffective.
https://www.ncbi.nlm.nih.gov/books/NBK572053/
23.1 The initial treatment of a trigeminocardiac reflex during skull base surgery should be
a. Tell surgeons to stop stimulus
b. Atropine
c. LA to site
a) Tell the surgeons to stop stimulus
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1821135/
https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/1864754
Careful dissection for prevention and early intervention with stimulus removal and anticholinergic use as needed are paramount to ensure good outcomes
N.B
Trigeminocardiac reflex refers to the sudden development of bradycardia or even asystole with arterial hypotension from manipulation of any sensory branches of the trigeminal nerve. Although it has only rarely been associated with morbidity and tends to be self-limited with removal of the stimulus, it is an important phenomenon for head and neck surgeons to recognize and respond to
Following a severe spinal cord injury, return of reflexes is usually seen after
a. <1 day
b. 1-3 days
c. 7 days
d. 1-4 weeks
e. >1 month
Answer: b, 1-3 days
BJA 2013 Initial Management of Acute Spinal Cord Injury
Spinal shock is the loss of reflexes below the level of SCI resulting in the clinical signs of flaccid areflexia and is usually combined with hypotension of neurogenic shock.
There is a gradual return of reflex activity when the reflex arcs below redevelop, often resulting in spasticity, and autonomic hyperreflexia.
This is a complex process and a recent four-phase classification to spinal shock has been postulated:
areflexia (Days 0 – 1),
initial reflex return (Days 1 – 3),
early hyperreflexia (Days 4 – 28), and
late hyperreflexia (1 – 12 months)
23.1 A feature that is atypical of multiple sclerosis is
A. Unilateral visual loss
B. Aphasia
C. Diplopia
D. Lower limb motor
E. Some sensory thing
B. Aphasia
UTD
22.2 A patient with an acute subarachnoid haemorrhage arrives in the emergency department. Her Glasgow Coma Scale score is 10 and she has no motor deficit. A CT brain shows diffuse subarachnoid haemorrhage with no localised areas of blood > 1 mm thick, and no intracerebral nor intraventricular blood. Her World Federation of Neurosurgical Societies (WFNS) grade of subarachnoid haemorrhage is
a) 1
b) 2
c) 3
d) 4
e) 5
4
GCS 7-12
23.1 A 50-year-old man presents with a subarachnoid haemorrhage. He undergoes
cerebral angiography and the frontal view is shown below. His cerebral aneurysm is
in the
(exact image on exam)
a. Anterior choroidal
b. Anterior communicating artery
c. MCA
d. PCA
b) anterior communicating artery
https://case.edu/med/neurology/NR/SubarachnoidHemorrhageAComm3.htm
https://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-0039-1681979.pdf
https://case.edu/med/neurology/NR/NRHome.htm (scroll down to subarachnoid imaging area)
20.2 The most common type of perioperative stroke is
a) Hypoxic
b) Thrombotic
c) Embolic
d) Hypotensive
e) Haemorrhagic
c) Embolic
Blue Book 2017
Perioperative Stroke
Epidemiology
A perioperative stroke is defined as one that occurs either intra-operatively or in the post-operative period within 30 days70. Perioperative strokes are associated with an increased length of stay and a six-fold increased mortality. Any combination of surgery and anaesthesia is associated with an increased risk of stroke irrespective of the type of surgery. This may relate to coagulation changes
The most common type of perioperative stroke is ischaemic stroke of embolic origin (heart or aorta). Hypotension is rarely the cause of perioperative stroke. Haemorrhagic stroke is uncommon which probably reflects the fact that severe hypertension during anaesthesia is a rare event, and anticoagulants have typically been withheld.
The risk of perioperative stroke varies depending on the type of the surgery and patients’ risk factors.
Procedural risk
Urgent surgery is associated with an increased risk of stroke when compared to elective surger.
Cardiac, vascular and brain surgeries are defined as “high-risk” as these have an increased risk of stroke when compared to other types of surgery. Valvular and aortic repair surgeries have a stroke risk as high as 8 to 10 per cent.
Perioperative strokes in non-high-risk surgery are relatively rare and are estimated to have an incidence of about 1/1000 cases80.
Patients’ risk factors
>Age
>history of previous stroke or transient ischaemic attack
>renal failure
>atrial fibrillation
>history of cardiovascular diseases
are identified risk factors for perioperative stroke.
Atrial fibrillation is associated with a two-fold increase in the risk of death and stroke after carotid endarterectomy.
A 50-year-old woman has had a headache for the last month which is relieved by lying flat. She has had no medical procedure to her spine such as epidural, spinal or lumbar puncture. Her brain magnetic resonance imaging (MRI) scan shows diffuse meningeal enhancement and brain sagging. Her neurologist suspects spontaneous intracranial hypotension and asks you to do an epidural blood patch. No spinal imaging has been performed to confirm a cerebrospinal fluid (CSF) leak. You should
A do LP to measure pressure if low do lumbar patch
B do blood patch at lumbar level with no further investigation
C do spine imaging if CSF leak present do blood patch at level
D do spine imaging if CSF leak present do lumbar blood patch
E refuse to do blood patch
B do blood patch at lumbar level with no further investigation
21.2 A patient presents for endovascular clot retrieval after experiencing a right hemisensory loss and right homonymous hemianopia. The vessel most likely occluded is the left
a) ACA
b) MCA
c) PCA
d) AICA
e) PICA
Left PCA
bonus neuro radiology questions
A 23 year-old man developed the abrupt onset of an explosive headache followed by nausea and vomiting. On exam, he had a right third nerve palsy.
He undergoes cerebral angiography.
His cerebral aneurysm is in the
a. Anterior Cerebral Artery
b. Anterior communicating artery
c. MCA
d. PCA
e. Basilar artery
d. PCA
https://case.edu/med/neurology/NR/SubarachnoidHemorrhag3%20Pcom3.htm
23.1 A patient is undergoing a posterior spinal fusion with somatosensory evokedpotential (SSEP) monitoring. Ischaemia is suggested by
a. Increased amplitude, increased latency
b. Increased amplitude, decreased latency
c. Decreased amplitude, increased latency
d. Decreased amplitude, decreased latency
c. Decreased amplitude, increased latency
20.2 During spinal surgery, the anaesthetic agent that is least likely to decrease motor evoked potentials is
A. Non-depolarising muscle relaxants
B. Nitrous oxide
C. Opioids
D. Propofol
E. Volatiles
C. Opioids
A. Non-depolarising muscle relaxants - false - NMBDs abolish MEPs
B. Nitrous oxide - false - N2O can completely abolish MEPs
D. Propofol - false - PPF has less of an effect than volatiles, but still affects MEPs
E. Volatiles - false - volatiles are the most likely
NMBDs > volatiles > N2O > PPF > opioids
https://www.uptodate.com/contents/anesthesia-for-elective-spine-surgery-in-adults
While neurologic injury can cause changes in recorded potentials, other factors can interfere with interpretation. Confounding factors that can occur during surgery include inhalational anesthetics, hypothermia, hypotension, hypoxia, anemia, and preexisting neurologic lesions. Inhaled anesthetics such as isoflurane, sevoflurane, and nitrous oxide can reduce the amplitude and prolong the latency of SSEP and can completely abolish MEP. Neuromuscular blocking agents (NMBAs) also abolish motor evoked potentials and cannot be used when monitoring. Intravenous anesthetics such as propofol, barbiturates, and opioids have less of an effect on monitoring, though very deep anesthesia, even with propofol, can affect waveforms.
https://www.uptodate.com/contents/neuromonitoring-in-surgery-and-anesthesia
Evoked potentials — Evoked potential monitoring is used to assess the integrity of the tested neural pathway. Somatosensory, visual, and brainstem auditory evoked potentials monitor neurologic structures between peripheral sites where specific stimulations are applied, and responses are recorded from central locations. Motor evoked potentials monitor such structures by stimulating the motor cortex and recording from the epidural space (D-wave) or, more commonly, from distal muscles. Changes in evoked responses can result from technical, positional, pharmacologic, physiologic, or surgical causes.
For spine surgery, both MEPs and SSEPs are used to monitor spinal cord function to increase sensitivity. Motor and sensory tracts are anatomically distinct and have different vascular supply in areas of the cortex, brainstem, and spinal cord.
Motor evoked potentials (MEPs) – MEP responses are affected by even very low concentrations of volatile anesthetic agents. In general, total intravenous anesthesia (TIVA) facilitates MEP monitoring. However, inhalation agents at 0.5 MAC or less can be used in many patients, especially during intracranial surgery
Opioids – IV opioids cause small, dose-dependent depression of SSEP and MEP responses, though even at very high doses of opioids, evoked potentials can be recorded [76-78]. Infusions of remifentanil, fentanyl, or sufentanil are commonly used as part of TIVA during neuromonitoring. Opioids tend to produce high-amplitude slow waves in the EEG.
Balanced anesthetic approach — When SSEPs and MEPs are monitored, a balanced anesthetic using both a low-dose inhalation anesthetic (up to 0.5-MAC isoflurane, sevoflurane, or desflurane) and low- to medium-dose propofol (eg, propofol, 40 to 75 mcg/kg/min IV) with a relatively high-dose opioid (eg, remifentanil 0.1 to 0.4 mcg/kg/min) offers several advantages:
●Movement with motor stimulation is reduced, which is particularly important during intracranial aneurysm surgery.
●The addition of a 0.3 to 0.5 MAC inhalation agent may reduce the chance of awareness under anesthesia.
●Compared with TIVA, the addition of a 0.5 MAC inhalation agent allows reduction of the dose of propofol infusion, facilitating more rapid wakeup and earlier neurologic examination.
●Compared with TIVA, the chance of accidental interruption of the anesthetic for mechanical reasons (ie, kinked or infiltrated IV catheter or tubing such that IV agents no longer infuse) is reduced.
21.2 A patient has numbness and weakness in her hand postoperatively. You are trying to distinguish between an ulnar nerve lesion and a C8-T1 radiculopathy. You can diagnose a C8-T1 radiculopathy if she has weakness
A. Parasthesia in little finger
B. Parasthesia in the distribution of the interscalene nerve
C. Weakness in adductor digiti minimi
D. Weakness in abductor pollicis brevis
E. Weakness in lateral interosseus
Muscles weak in C8-T1 radiculopathy but intact in ulnar neuropathy
- flexor pollicis brevis
- abductor pollicis brevis
- opponens pollicis
- lateral lumbricals
AbOF the Law may be useful—the abductor (Ab) and flexor (F) pollicis brevis, opponens pollicis (O), and lateral lumbricals (Law) are “above the law” that intrinsic hand muscles are ulnar-innervated
21.1 A patient has numbness and weakness in her hand postoperatively. You are trying to distinguish between an ulnar nerve lesion and a C8-T1 radiculopathy.
You can diagnose a C8-T1 radiculopathy if she has weakness
a) Thumb adduction
b) Thumb abduction
c) Fingers adduction
d) Fingers Abduction
e) Little finger flexion
b) Thumb abduction
(flexor pollicis brevis)
D. Paraesthesia/sensory loss over medial forearm
(medial antebrachial cutaneous)
Severing Ulnar nerve alone results in numbness of the 4th (ring) and 5th (little) fingers alone
C8 and T1 supply the medial antebrachial cutaneous nerve
Muscles weak in C8-T1 radiculopathy but intact in ulnar neuropathy
- flexor pollicis brevis
- abductor pollicis brevis
- opponens pollicis
- lateral lumbricals
AbOF the Law may be useful—the abductor (Ab) and flexor (F) pollicis brevis, opponens pollicis (O), and lateral lumbricals (Law) are “AbOF the Law” that intrinsic hand muscles are ulnar-innervated
The initial management for a seizure during an awake craniotomy is
a. Cold saline irrigation
b. Midazolam
c. Propofol
a) Cold Saline Irrigation
23.1 The neurosurgical registrar has telephoned about a patient with a spinal cord tumour who is on the list for tomorrow. The registrar tells you the patient has Brown-Séquard syndrome (hemisection of the spinal cord). On clinical examination, below the level of the lesion, you would expect to find all EXCEPT ipsilateral
A. Hyperreflexia
B. Loss of tactile stimulation
C. Paralysis
D. Loss of pain/temperature
E. Loss of vibration/proprioception
d) loss of pain and temperature
20.2 A patient presents with a serum sodium of 110mmol/L. A feature NOT consistent with a diagnosis of syndrome of inappropriate antidiuretic hormone (SIADH) is
a. urinary sodium >40
b. Euvolemia
c. Increased cortisol
d. Urine osmolarity <100
e. Serum Na <145
d. Urine osmolarity <100
DIAGNOSTIC CRITERIA
>hypotonic hyponatraemia
>urine osmolality > plasma osmolality (<275mOsm/kg) (i.e. concentrated urine despite hypotonic blood)
>urinary Na+ > 20mmol/L
>normal renal, hepatic, cardiac, pituitary, adrenal and thyroid function
>euvolaemia (absence of hypotension, hypovolaemia, and oedema)
correction by water restriction
CAUSES (MAD CHOP)
Major Surgery
>abdominal
>thoracic
>transsphenoidal pituitary surgery (6-7 days post op)
ADH production by tumours (Ectopic)
>small cell bronchogenic carcinoma
>adenocarcinoma of pancreas/duodenum
>leukaemia
>lymphoma
>thymoma
Drugs
>antidepressants (e.g. SSRI, TCAs, MAOIs)
>psychotropics (e.g. haloperidol, chlorpromazine), carbamazepine, Na+ valproate)
>anaesthetic drugs (barbiturates, inhalational agents, oxytocin, opioids)
>ADH analogues (vasopressin, DDAVP)
>chemotherapy (e.g.Vinca alkaloids, Melphalan, Methotrexate and cyclophosphamide)
>others (e.g. NSAIDs, amiodarone, ciprofloxacin, morphine, MDMA, proton pump inhibitors)
CNS Disorders
>cerebral trauma
>brain tumour (primary or metastases)
>meningitis/encephalitis
>brain abscess
>SAH
>acute intermittent porphyria
>SLE
Hormone deficiency
>hypothyroidism
>adrenal insufficiency
Others
>Guillain-Barre Syndrome
>HIV infection (early symptomatic or AIDS)
>hereditary SIADH
>giant cell arteritis
>idiopathic (occult small cell or olfactory neuroblastoma)
Pulmonary Disorders
>pneumonia (viral, fungal, bacterial)
>TB
>lung abscess
MANAGEMENT
1. see hyponatraemia
2. fluid restrict
3. incremental increase in Na+ if indicated to avoid central pontine myelinolysis
4. medications to decrease ADH secretion
>Demeclocycline
>Tolvaptan / Conivaptan
22.2 During spinal surgery, the anaesthetic agent that is least likely to decrease motor evoked potentials is
a Ketamine
b Precedex
c Propofol
d Volatiles
e Remifentanil
Ketamine
22.1 A patient has undergone a multilevel cervical spine fusion and upon emergence from anaesthesia reports complete visual loss. Fundoscopic examination shows a pale optic disc with haemorrhages. This supports a diagnosis of
a. CRAO
b. AION
c. PION
Ischaemic optic neuropathy (anterior)
https://www.researchgate.net/figure/Top-Funduscopic-examination-revealed-pale-and-swollen-discs-with-small-hemorrhages-on_fig2_6759964
22.2 The initial management for a seizure during an awake craniotomy is
a. GA and tube
b. Cold saline irrigation of brain
c. IV keppra
d. IV propofol
e. IV midazolam
b. Cold saline irrigation of brain
Seizures, either focal or generalized, are most likely to occur during cortical mapping. They are treated by irrigating the brain tissue with ice-cold saline. They usually cease with this treatment alone, but occasionally benzodiazepines, anti-epileptic drugs, or re-sedation with airway control are required.
An emergency plan for airway control has to be in place at all times and this can be challenging as the patient’s head is fixed in head pins and often away from the ventilator. The options include the insertion of an LMA which may be easier than oro-tracheal intubation.
Awake craniotomy is generally a well-tolerated procedure with a low rate of conversion to general anaesthesia and a low rate of complications. One of the most frequent complications is patient intolerance of the procedure, often because of the urinary catheter or prolonged positioning and intra-operative seizures.
21.1 A patient has numbness and weakness in her hand postoperatively. You are trying to distinguish between an ulnar nerve lesion and a C8-T1 radiculopathy.
You can diagnose a C8-T1 radiculopathy if she has
A. Paraethesia of the 5th digit
B. Paraesthesia over index finger
C. Flexor carpi ulnaris function
D. Paraesthesia/sensory loss over medial forearm
E. Adductor pollicis function
Remembered answers don’t help differentiate.
[A. Paraethesia of the 5th digit - can be ulnar only
B. Paraesthesia over index finger - will be median only
C. Flexor carpi ulnaris function - can be ulnar only
D. Paraesthesia/sensory loss over medial forearm - can be ulnar only
E. Adductor pollicis function - can be ulnar only
C8-T1 radiculopathy
Will cause:
Loss of Thumb and finger abduction
(flexor pollicis brevis - suppled by both ulnar deep branch (C8-T1) and median nerve lateral terminal branch C6-T1)
Severing Ulnar nerve alone results in numbness of the 4th (ring) and 5th (little) fingers alone, and potentially medial forearm sensation (C8 and T1 supply the medial antebrachial cutaneous nerve), although loss of forearm sensation is more common in C6 radiculopathies.
All intrinsic muscles of the hand are innervated by the ulnar nerve, except for 4 muscles supplied by the median nerve. These muscles may be weak in C8-T1 radiculopathy but intact in ulnar neuropathy.
- flexor pollicis brevis
- abductor pollicis brevis, in part.
- opponens pollicis
- lateral lumbricals
AbOF the Law
may be useful—the abductor (Ab) and flexor (F) pollicis brevis, opponens pollicis (O), and lateral lumbricals (Law) are “above the law”
Or
LOAF
20.1 The Brain Trauma Foundation guideline for management of severe head trauma recommend the treatment of intracranial pressures greater than
a. 5mmHg
b. 10
c. 15
d. 22
e. 25
22
22.1 Venous air embolism during frontal craniotomy is most likely to arise from the
a. Transverse sinus
b. Sigmoid sinus
c. Superior sagittal
d. Straight
c. Superior sagittal
Risk factors for venous air embolism include sitting craniotomy, posterior fossa surgery and procedures near the superior sagittal sinus. In these situations, the surgical site is often above the level of the right atrium and hence venous air entrainment is facilitated, or there is a large risk of venous exposure through which air may be entrained. Depending on the volume of air entrained, reduced end-tidal carbon dioxide, arrhythmias or right heart failure and cardiovascular collapse are all possible. However, changes in clinical parameters often occur late and are nonspecific for small volumes of entrainment. Specific monitoring for detection of venous air embolism includes non-invasive means such as end-tidal nitrogen, precordial Doppler or stethoscope and transcranial Doppler. Invasive methods include transoesophageal echocardiography, oesophageal stethoscope, pulmonary artery catheter and central venous pressure monitoring.
https://resources.wfsahq.org/atotw/anaesthesia-for-craniotomy-and-brain-tumour-resection/
A 65-year-old woman has presented with a grade 2 subarachnoid haemorrhage equally suitable for treatment with surgical clipping or endovascular coiling. The factor shown to most effectively reduce mortality in early subarachnoid haemorrhage treatment is
a) Nimodipine
b) Tranexamic acid
c) Early repair
d) Atorvastatin
e) EVD placement
c) Early repair
Coil within 24 hours
Early repair - the outcome in terms of survival free of disability at 1 year is significantly better with endovascular coiling. Preferably within 24 hours
20.2 The most common cause of post operative visual loss after spinal surgery is
a) Corneal abrasion
b) Retinal artery occlusion
c) Central retinal vein occlusion
d) Ischaemic optic neuropathy
e) Occipital infarct
a) Ischaemic optic neuropathy
Postoperative visual loss (POVL) occurs in 1/60 000–1/125 000 operations. Spinal surgery has the highest incidence of POVL.
American Society of Anesthesiologists (ASA) Post Operative Visual Loss Registry, spinal surgery accounted for 93/131 (70%) of all cases of visual loss after non-ophthalmic surgery.
Of these:
> 83 were attributable to ischaemic optic atrophy (ION)
> 10 were caused by central retinal artery occlusion (CRAO).
CRAO
- caused by direct pressure on the globe causing raised intraocular pressure and compromising retinal perfusion.
- visual loss is usually unilateral and associated with other signs of pressure (e.g. ophthalmoplegia, ptosis, or altered sensation in the territory of the supraorbital nerve).
- Initial careful positioning of the head and regular checks throughout the procedure in case of movement minimizes the risk
- documentation of eye checks should occur every 30mins and horseshoe shaped head rests should be avoided in prone patients
ION
> associated with:
- male gender
- obesity
- increasing blood loss
- operative procedures >6 hrs in length.
- The use of the Wilson frame has also been implicated.
> final common pathway is thought to be hypoperfusion of the optic nerve, there is no clear association with either intraoperative systemic hypotension or with the presence of peripheral vascular disease or diabetes.
> recently updated ASA practice advisory for POVL associated with spinal surgery recommends regular intraoperative testing of haemoglobin concentration. However, it was unable to suggest a transfusion threshold that would prevent POVL.
Other possible causes of POVL:
1. Cortical ischaemia
2. Haemorrhage into a cerebral tumour.
In high-risk cases, assessment of vision should be performed as soon as possible in PACU and an early ophthalmic opinion sought if there is a suggestion of visual compromise.
Initial management
1. optimization of arterial pressure
2. oxygenation
3. correction of anaemia.
Treatment with agents such as acetazolamide has not been beneficial and there is rarely any useful improvement in vision with either injury, so attention should be focused on preventative measures:
1. Careful positioning with the head at the same level as the heart
2. Meticulous haemostasis,
3. Possibly staging prolonged procedures should be considered.
Because of the devastating nature of this complication, patients should be informed of an increased incidence of visual loss after spinal operations that are expected to be of prolonged duration and associated with significant blood loss.
22.2 A 72-year-old patient is undergoing resection of an anterior skull based tumour using a combined endoscopic and frontal craniotomy approach. Seven hours into the procedure she has a large diuresis of pale urine and you suspect she may have developed diabetes insipidus. The most appropriate test result to confirm your diagnosis in this setting is a
a. Low serum ADH levels
b. Sequentially increasing Na levels
c. Serum osmolality <260
d. Urine Na >40
e. Urine specific gravity > something
b. Sequentially increasing Na levels
bonus neuro radiology questions
A 24 year-old man developed an explosive headache followed by nausea and vomiting.
He undergoes cerebral angiography.
His cerebral aneurysm is in the
a. Anterior Cerebral Artery
b. Anterior communicating artery
c. MCA
d. PCA
e. Basilar artery
b. Anterior communicating artery
https://case.edu/med/neurology/NR/SubarachnoidHemorrhageAComm.htm
23.1 A patient with an acute subarachnoid haemorrhage arrives in the emergency department. Her Glasgow Coma Scale score is 10 and she has no motor deficit. A CT brain shows diffuse subarachnoid haemorrhage with no localised areas of blood greater than 1mm thick, and no intracerebral or intraventricular blood. Her World Federation of Neurosurgical Societies (WFNS) grade of subarachnoid haemorrhage is
A. 1
B. 2
C. 3
D. 4
E. 5
D. 4
- alternatively her Fisher score is: grade 2 (diffuse thin (<1 mm) SAH, no clots; which estimates an incidence of symptomatic vasospasm of 25%)
Note the new modified Fischer scale.
G0 No SAH or IVH (0%)
G1 Focal or diffuse thin SAH but no IVH (6-24%)
G2 Focal or diffuse thin SAH with IVH (15-33%)
G3 Thick SAH no IVH (33-35%)
G4 Thicc SAH with IVH (34-40%)
The main differences between the Fisher scale and modified Fisher scale are:
1) Fisher scale, no SAH is grade 1, but 0 in modified Fisher scale
2) Fisher scale, thin SAH & no IVH is grade 2, but 1 in modified Fisher scale
3) Fisher scale, thick SAH with no IVH is grade 3 and the same 3 in modified Fisher scale
4) Fisher scale, any IVH is grade 4, irrespective of the presence of SAH but in modified Fisher scale it is either 2 if thin or no SAH, or grade 4 if thick SAH
Modified Fisher Scale:
grade 0
- no subarachnoid hemorrhage (SAH)
- no intraventricular hemorrhage (IVH)
- incidence of symptomatic vasospasm: 0% 3
grade 1
- focal or diffuse, thin SAH
- no IVH
- the incidence of symptomatic vasospasm: 24%
grade 2
- focal or diffuse, thin SAH
- IVH present
- the incidence of symptomatic vasospasm: 33%
grade 3
- thick SAH
- no IVH
- the incidence of symptomatic vasospasm: 33%
grade 4
- thick SAH
- IVH present
- the incidence of symptomatic vasospasm: 40%
Note: the original study did not include a specified measurement or criteria to define thick vs thin hemorrhage.
REPEAT
22.1 Following the initial subarachnoid haemorrhage from a ruptured aneurysm, the patient is at greatest risk of rebleeding during the following
a. 1-3 days
b. 3-5 days
c. 5-7 days
d. 7-10 days
a. 1-3 days
bonus neuro radiology questions
A 34 year-old woman developed the lightning onset of an explosive headache followed by nausea and vomiting.
She undergoes cerebral angiography.
Her cerebral aneurysm is in the
a. Anterior Cerebral Artery
b. Anterior communicating artery
c. MCA
d. PCA
e. Basilar artery
d. PCA
https://case.edu/med/neurology/NR/SubarachnoidHemorrhag3%20Pcom.htm
22.1 A 50-year-old man is admitted with a stroke and undergoes cerebral angiography. The artery
marked by the arrow on the angiogram is the
a. Vertebral
b. Basilar
c. PCA
d. PICA
e. Anterior cerebral artery
21.1 Of the following, the incidence of venous air embolism is considered highest for
a) LUSCS
b) Prostatectomy
c) Coronary artery surgery
d) Spinal surgery
e) Gastric endoscopy
a) LUSCS
Rates of VAE by surgical procedure:
LUSCS: 10%-97%
Neurosurgery:
Posterior Fossa: 76%
Cervical Laminectomy: 7-25%
Lateral/Prone Neurosurgery: 15-25
%
Total Hip Replacement: 30%
Lap Cholecystectomy: 69%
A 50-year-old man is admitted with a stroke and undergoes cerebral angiography. The artery marked on angiography is the
a) Anterior Cerebral Artery
b) Middle Cerebral Artery
c) Posterior Cerebral Artery
d) Basillar Artery
e) Superior Cerebellar Artery
Answer: This time thought to be posterior cerebral (previously middle cerebral)
22.2 Unsupported ventilation in a non-anaesthetised patient with long-standing tetraplegia is improved when
a) Left lateral
b) Right lateral
c) Supine
d) Trendelenberg
e) Reverse Trendelenberg
d) Trendelenberg c) Supine
Moving from upright to supine affects the respiratory function of the tetraplegic and high paraplegic individual differently to the able-bodied person.
The increase in abdominal girth when sitting in tetraplegia is secondary to decreased abdominal muscle strength and the associated increased abdominal wall compliance.
In the seated position, the abdominal contents are less supported by the decreased abdominal wall muscle tone and fall forward, increasing the waist size and lowering the diaphragm.
In able-bodied subjects, the FVC is reduced in the supine position, whereas in tetraplegia it is increased.
Postural changes are associated with symptoms; patients with an acute, high SCI report less breathlessness when supine compared to sitting.
In the supine position, the weight of the abdominal contents forces the diaphragm to a higher resting level so that contraction produces greater absolute excursion of the diaphragm; an effect that can be increased when the person with tetraplegia is tipped 15° head down from supine such that the vital capacity rises by a further 6%
22.2 A patient under general anaesthesia monitored with transcranial cerebral oximetry has a decrease in their cerebral oxygen saturation. This is likely to be improved by an increase in all of the following EXCEPT
A. Increasing blood pressure
B. Deepening anaesthesia
C. Increased minute ventilation
D. Transfusion
C. Increased minute ventilation
Cerebral blood flow
Cardiac output
Acid–base status
Major haemorrhage
Arterial inflow/venous outflow obstruction
Oxygen content
Haemoglobin concentration
Haemoglobin saturation
Pulmonary function
Inspired oxygen concentration
Inspired oxygen concentration
21.2 A patient with an acute subarachnoid haemorrhage arrives in the emergency department. Her Glasgow Coma Scale is 10 and she has no motor deficit. A CT brain shows diffuse subarachnoid haemorrhage with no localised areas of blood > 1mm thick, and no intracerebral nor intraventricular blood. Her World Federation of Neurosurgical Societies
(WFNS) grade of subarachnoid haemorrhage is
a) 1
b) 2
c) 3
d) 4
e) 5
d) 4
- WFNS is 4
* alternatively her Fisher score is: grade 2 (diffuse thin (<1 mm) SAH, no clots; which estimates an incidence of symptomatic vasospasm of 25%)
Note the new modified Fischer scale.
G0 No SAH or IVH (0%)
G1 Focal or diffuse thin SAH but no IVH (6-24%)
G2 Focal or diffuse thin SAH with IVH (15-33%)
G3 Thick SAH no IVH (33-35%)
G4 Thicc SAH with IVH (34-40%)
The main differences between the Fisher scale and modified Fisher scale are:
1) Fisher scale, no SAH is grade 1, but 0 in modified Fisher scale
2) Fisher scale, thin SAH & no IVH is grade 2, but 1 in modified Fisher scale
3) Fisher scale, thick SAH with no IVH is grade 3 and the same 3 in modified Fisher scale
4) Fisher scale, any IVH is grade 4, irrespective of the presence of SAH but in modified Fisher scale it is either 2 if thin or no SAH, or grade 4 if thick SAH
22.2 The rate of drainage of cerebrospinal fluid via a lumbar drain is NOT influenced by the
a. Height of bed
b. Height of drainage chamber
c. Height of highest part of drainage system
d. Position of patient
e. Spinal level of drain
e. Spinal level of drain
According to AANN2 and SNACC4 Guidelines:
* Patient positioning and leveling is crucial to prevent complications from lumbar drainage
* The head of the bed, height of drainage chamber, and changes in patient positioning must be monitored closely to prevent sudden overdrainage
* While making changes to the patient’s positioning, the lumbar drainage device should be clamped so that overdrainage does not occur
https://www.integralife.com/file/general/1604065981.pdf
(manufacturer’s instructions)
23.1 Cerebral salt wasting and syndrome of inappropriate antidiuretic hormone secretion
(SIADH) have the following common features EXCEPT for
a. High urinary concentration
b. High urinary osmolality
c. Increased extracellular fluid
c. inc extracellular fluid
https://derangedphysiology.com/main/required-reading/electrolytes-and-fluids/Chapter%20531/hyponatremia-lazy-mans-classification
23.1 In order to provide anaesthesia of the scalp for awake craniotomy, it is necessary to
block branches of the
a. Greater and lesser occipital and greater auricular nerves
b. Trigeminal, greater and lesser occipital nerves
c. Trigeminal, greater occipital and greater auricular nerves
d. Facial, trigeminal and greater occipital nerves
e. Facial, greater and lesser occipital nerves
b) Trigeminal, greater and lesser occipital nerves
2005 blue book article: six nerves need to be blocked bilaterally
- supratrochlear
- supraorbital
- zygomaticotemporal
- auriculotemporal
- lesser occipital nerve
- greater occipital nerve
Minor contributions from the greater auricular nerve and third occipital nerve rarely encroach into the surgical field
21.2 A 50-year-old man is admitted with a stroke and undergoes cerebral angiography. The artery
marked with an ORANGE arrow on the angiogram below is the
a) Vertebral
b) Basilar
c) PICA
d) Superior cerebellar
e) Anterior cerebral
a) Vertebral
orange = vertebral
blue = basilar
purple = PCA
red arrows = AICA
yellow = pontine arteries
Circle of Willis:
bonus neuro radiology questions
A 45 year-old man developed the lightning onset of an explosive headache followed by coma.
He undergoes cerebral angiography.
His cerebral aneurysm is in the
a. Anterior Cerebral Artery
b. Anterior communicating artery
c. MCA
d. PCA
e. Basilar artery
e. Basilar
https://case.edu/med/neurology/NR/SubarachnoidHemorrhag3%20Bas2.htm
bonus neuro radiology questions
A 33 year-old man developed the explosive onset of a headache followed by nausea and vomiting.
He undergoes cerebral angiography.
His cerebral aneurysm is in the
a. Anterior Cerebral Artery
b. Anterior communicating artery
c. MCA
d. PCA
e. Basilar artery
a. Anterior Cerebral Artery
https://case.edu/med/neurology/NR/ACAaneur.html
The most common cause of airway compromise after anterior cervical spine surgery is
A. Aspiration
B. RLN injury
C. Oedema
D. Phrenic nerve injury
E. Haematoma
C. Oedema
Blue book 2017
The aetiology of UAO differs from that of airway compromise seen after thyroid or carotid surgery.
Haematoma formation and cerebrospinal fluid leak are potential complications of CSS that usually present early in the postoperative period, whereas upper airway obstruction most commonly develops in the late postoperative period (days rather than hours).
UAO occurs because of prevertebral tissue swelling that evolves late in the postoperative course.
The danger is that the onset can be insidious in a ward environment, leading to late recognition and limited availability of practitioners with airway expertise12.
Development of prevertebral oedema has been implicated in several near misses and deaths, which became the sentinel events that stimulated creation of departmental protocols to safely manage these patients postoperatively
bonus neuro radiology questions
A 45 year-old man developed the abrupt onset of an explosive headache followed by nausea and vomiting. On exam, he was drowsy with subtle left sided weakness.
He undergoes cerebral angiography.
His cerebral aneurysm is in the
a. Anterior Cerebral Artery
b. Anterior communicating artery
c. MCA
d. PCA
e. Basilar artery
c. MCA
https://case.edu/med/neurology/NR/mcaanery.htm
A patient under general anaesthesia monitored with transcranial cerebral oximetry has a decrease in their cerebral oxygen saturation. This is likely to be improved by an increase in all of the following EXCEPT
A. Increasing blood pressure
B. Deepening anaesthesia
C. Increased minute ventilation
D. Transfusion
C. Increased minute ventilation
Cerebral blood flow
Cardiac output
Acid–base status
Major haemorrhage
Arterial inflow/venous outflow obstruction
Oxygen content
Haemoglobin concentration
Haemoglobin saturation
Pulmonary function
Inspired oxygen concentration
Inspired oxygen concentration
A 42-year-old female is admitted with subarachnoid haemorrhage. She has a severe
headache, has eyes open spontaneously, and is confused but is obeying commands. She is unable to move her left side. The World Federation of Neurological Surgeons grade is
a) 1
b) 2
c) 3
d) 4
e) 5
C:3 (Pt is GCS 14 E4V4M6, with motor deficit)
The WFNS scale:
Grade 1: GCS 15, no motor deficit.
Grade 2: GCS 13-14 without deficit
Grade 3: GCS 13-14 with focal neurological deficit
Grade 4: GCS 7-12, with or without deficit.
Grade 5: GCS <7 , with or without deficit.
(BJA Education, Deranged Physiology)
This patient has been requested to look straight ahead. He is suffering from a right
a) Horner’s Syndrome
b) 3rd nerve palsy
c) 4th nerve palsy
d) 6th nerve palsy
b) 3rd nerve palsy
https://derangedphysiology.com/main/required-reading/neurology-and-neurosurgery/Chapter%204631/lesions-oculomotor-nerve-cn-iii
This is the “down and out” eye syndrome. It is characterised by ptosis, a down-and-out pupil, mydriasis, absent light reflex with intact consensual constriction of the opposite eye, and failure of accommodation. Classically, this is the lesion which develops during uncal herneation, due to an ipsilateral cerebral injury.
Causes of unilateral CN III lesions:
- Uncal herneation: Pressure from herniating uncus on nerve
- Fracture involving ipsilateral cavernous sinus
- Cavernous sinus thrombosis (ipsilateral)
- Aneurysm (ipsilateral)
- Midbrain lesion (see Question 26.2 from the second paper of 2011)
Causes of bilateral CN III lesions:
- Cavernous sinus thrombosis
- Aneurysm
- Contralateral brainstem lesion (midbrain)
Exclusion of a 4th nerve lesion
- Tilt the head to the same side as the lesion
- The affected eye will intort if the fourth nerve is intact.
