Neurosurgery Flashcards
- You are the ED intern on duty. You are asked to see a 20 year-old who was struck on the left side of his head by a cricket ball. Initially he was drowsy and a bit confused, then he appeared to recover completely. He is now mildly confused, he has a severe headache and has vomited four times. His pulse is 60 bpm and regular, and his BP is 170/110 mmHg. During the examination his GCS drops rapidly to 8/15.
What is your differential diagnosis and what investigations would you like?
The pt presents with a severe headache, vomiting, an altered level of consciousness and hypertension which are all signs of increased intracranial pressure.
As the pt also presents with a lucid interval after being struck on the side of the head, I’d be concerned of an extradural haemorrhage from the middle meningeal artery. However, other differentials on my list would include:
- subdural haemorrhage
- traumatic subarachnoud haemorrhage
- cerebral contusion or intracranial haemorrhage
On examination I’d examine the scalp for lacerations, fractures and contusions and I’d assess for any neurologic deficits. A GCS drop to 8 indicates that this is a severe head injury and I would go through the primary survey and resuscitate if necessary with the importance on airway management (intubate)
For investigations, I would like:
- an urgent non-contrast CT of the head
- pathology would include: FBC, blood glucoses, UEC, LFT, Coagulations studies, group and hold and ABG (Ventilation targets should be based on blood gas analysis and adjusted accordingly, aiming for a PaCO2 of 35–40 mmHg and a Sa02 94-98%.)
- You are the ED intern on duty. You are asked to see a 20 year-old who was struck on the left side of his head by a cricket ball. Initially he was drowsy and a bit confused, then he appeared to recover completely. He is now mildly confused, he has a severe headache and has vomited four times. His pulse is 60 bpm and regular, and his BP is 170/110 mmHg. During the examination his GCS drops rapidly to 8/15.
What is your differential diagnosis and what has happened to cause this problem?
My main differential diagnosis is extradural haemorrhage but I would also want to rule out:
- subdural
- traumatic subararachnoid
- intracerebral or cerebral contusions
In this case, the pt has suffered a traumatic, high impact injury via a cricket ball.
As it has hit the side of the head I would be concerned about the involvement of the pterion as it is an area that is particularly susceptible to major injury due to the anterior branch of the middle meningeal artery running deep to the bone in the extra-dural space.
A fracture of the bones in this region can lacerate the artery and cause high pressure bleeding into the space.
There is an initial loss of consciousness due to the impact and injury to the brain parenchyma, however patients often recover and have a “lucid interval” of feeling well, until the intra-cranial pressure increases due to the mass effect of the extra-dural haematoma.
The raised ICP leads to the symptoms experienced.
There may also be intra-axial haemorrhage and cerebral oedema but the rapid change in symptoms is better explained by extra-dural haematoma.
EXTRA= Clinical symptoms and signs of raised ICP
- Headache
- N/V
- Confusion
- Decreased consciousness
- Focal neurological symptoms due to the mass, or herniation (subfalcine, uncal, tonsillar)
- Cushing’s triad (hypertension, bradycardia and respiratory depression/ irregularity) due to Brain Stem compression
- Ipsilateral dilated pupil – Oculomotor nerve compression
- Papilloedema- ccurs when there is a buildup of pressure in or around the brain, which causes the optic nerve to swell.
- A 56 year-old woman is brought to the ED by her partner. She had complained of a sudden onset, severe headache immediately before collapsing, unconscious on the floor. She has regained consciousness after a few minutes, and now complains of neck stiffness. PMH is completely unremarkable, other than being a long term smoker.
What is the likely diagnosis and what are the causes?
The most likely diagnosis is subarachnoid haemorrhage.
Some of the major causes of this condition include:
- rupture of saccular aneurysm (80-85%)
- rupture of an arterovenous malformation (10%)
- trauma
Risk factors include:
- smoking
- htn
- family hx- in particularly connective tissue disease
- alcohol consumptin
- drugs such as cocaine and amphetamine
EXTRA aneurysm locations= - ACA or A.Comm= 40% - internal carotid= 30% - middle cerebral= 20% - basilar or vertebral= 10%
- A 56 year-old woman is brought to the ED by her partner. She had complained of a sudden onset, severe headache immediately before collapsing, unconscious on the floor. She has regained consciousness after a few minutes, and now complains of neck stiffness. PMH is completely unremarkable, other than being a long term smoker.
What is the likely diagnosis, and how would the patient’s neurological condition best be monitored clinically during initial assessment?
The most likely diagnosis is subarachnoid hemorrhage.
Clinical monitoring of the pt will involve initial assessment and stabilization of the pt with primary survey including a GCS score to assess for altered level of consciousness.
o Eyes = 4 Spontaneously To verbal stimuli To painful stimuli None
o Motor = 6 To command Localises pain Withdraws to pain abnormal/spastic Flexion to pain rigid Extension to pain No motor response
o Verbal = 5 Oriented Confused Conversation Inappropriate words Incomprehensible sounds No verbal response
Ongoing vital monitoring with awareness of the cushing reflex which can present with increasing ICP.
A full initial neurological examination to assess for deficits in the cranial nerves such as CN3 compression which will present as pupil fixation that is unreactive to light. Whilst also assessing the upper and lower limbs for neurological deficits.
Fundoscopy can be done to look for papilledema- swelling of optic disc- caused by ICP.
- A 56 year-old woman is brought to the ED by her partner. She had complained of a sudden onset, severe headache immediately before collapsing, unconscious on the floor. She has regained consciousness after a few minutes, and now complains of neck stiffness. PMH is completely unremarkable, other than being a long term smoker.
What is the likely diagnosis and how would the diagnosis be confirmed?
The most likely diagnosis is subarachnoid haemorrhage and the diagnosis would be confirmed by:
- urgent non-contrast CT (done within first 6 hours of onset) which would show hyperdense collection within subarachnoid space in particularly the basal cisterns where the circle of willis is located. Blood can also be seen in the fissure and sulci.
- lumbar puncture which would be performed if there is a strong suspicion of SAH but the CT is normal. However, this can only be done 12 hours after onset of symptoms. Classic findings include: increased opening pressure, elevated RBC count and xanthochromia which can be confirmed by CSF spectrophotometry (yellow discoloration indicating the presence of bilirubin in the CSF)
OR MRI to look for blood products in the cerebrospinal fluid space
- A 56 year-old woman is brought to the ED by her partner. She had complained of a sudden onset, severe headache immediately before collapsing, unconscious on the floor. She has regained consciousness after a few minutes, and now complains of neck stiffness. PMH is completely unremarkable, other than being a long term smoker.
What is the likely diagnosis, and what is the usual treatment if this diagnosis is confirmed?
The most likely diagnosis is subarachnoid haemorrhage.
Initial care of patients with SAH is directed at reversing or stabilizing life-threatening conditions, particularly for comatose patients. Important steps include ensuring a secure airway, normalizing cardiovascular function, and treating seizures.
General management involves:
- Admission to ICU or specialist neurosurgical unit
- Patient may require intubation and mechanical ventilation if GCS<8 or respiratory failure.
- Bed rest, analgesia, anti-tussives (cough suppressor), stool softeners- diminish hemodynamic fluctuations and lower the risk of rebleeding prior to securing the aneurysm
- Close monitoring of vitals, blood gases, electrolytes, BGL and ECG
- Discontinuation of anticoagulants and reversal of anticoagulants
- Nimodipine for vasospasm prophylaxis
- anticonvulsants if pt has seizures
- IV fluids to maintain euvolaemia (watch for hyponatraemia)
- Antihypertensives to maintain SBP <140mmHg
Definitive management involves identifying the aetiology via CT angiography, magnetic resonance angiography or Digital Subtraction Angiography (DSA). Once the aneurysm is identified it is repaired with surgical clipping or endovascular coiling.
Surgical clipping involves a clip being placed across the neck of the aneurysm.
Endovascular coiling involves insertion of Platinum coils into the lumen of the aneurysm where local thrombus then forms around the coils, obliterating the aneurysmal sac.
- You are the ED intern on duty. You are asked to see a 75 year-old man who has been brought into the hospital from home where he has been becoming increasingly confused and clumsy. He was previously well and independent. He had a fall about three weeks ago, when he cut his forehead. He has little medical history of note, he used to smoke and still drinks about 30 standard units of alcohol per week. On direct questioning he is confused in time and place. Physical and neurological examination are normal.
- What is your differential diagnosis?
- What investigations would you like?
- Differential diagnoses for this pt include:
Neurological cause such as
- subdural hemorrhage
- ischemic stroke
- intracerebral hemorrhage
- Wernickes encephalopathy (alcohol related, due to thiamine deficiency)
Delirium- due to infection (UTI, pneumonia, meningitis, sepsis), electrolyte imbalance, hypovolemia, hypoglycemia, constipation, encephalopathy (hepatic or uremic –>kidney related), medications and drugs.
Alcohol intoxication or withdrawal
- Investigations I would include are:
- urgent non-contrast CT
- FBC, EUCs, BSL, lipid profile, LFTs (hepatic encephalopathy)
- Coagulation studies, group and save (if thrombotic/haemorrhagic cause suspected)
- Blood cultures (if infection)
- blood alcohol concentration
- ECG- electrolyte imbalance
- Chest X ray if suspicious of pneumonia
- urinalysis (?infection esp if there is known IDC use)
- You are the ED intern on duty. You are asked to see a 75 year-old man who has been brought into the hospital from home where he has been becoming increasingly confused and clumsy. He was previously well and independent. He had a fall about three weeks ago, when he cut his forehead. He has little medical history of note, he used to smoke and still drinks about 30 standard units of alcohol per week. On direct questioning he is confused in time and place. Physical and neurological examination are normal. A CT head shows a subdural haematoma.
- What has happened inside this man’s head?
- What treatment is required?
- Shearing forces result in the rupture of cortical bridging veins that pierce the dura and drain into the dural sinuses.
This results in accumulation of venous blood between the dura and arachnoid mater.
This is a large potential space, therefore the blood often spreads over a large area before exerting mass effect on the brain.
People with brain atrophy (i.e. older patients and chronic alcoholics) are at increased risk due to a relatively larger subarachnoid space and more fragile veins.
- The patient can be managed conservatively if there a no clinical signs of herniation, the pateint’s neurological status is stable, midline shift is less than 5mm, and the haematoma is less than 10mm in thickness. If any of the above criteria is not met then surgical decompression is necessary.
Conservative management involves:
- Regular neurological observation
- Serial CT scans to detect clot expansion
- Anti-coagulation reversal (consider then risk/ benefit ratio)
- ICP management: raise head of bed, mannitol, hyperventilation
Surgical decompression can be done via:
- Burr hole hole evacuation
OR
- Craniotomy and evacuation-(bone flap is removed from the skull and the haematoma is evacuated and flap is put back by end of surgery)
Craniotomy is the recommended surgical technique for patients with acute SubDural Hemorrhage and coma (defined as GCS score <9)
EXTRA
Mannitol is an osmotic diuretic that exerts its ICP-lowering effects via two mechanisms—an immediate effect because of plasma expansion and a slightly delayed effect related to its osmotic action. The early plasma expansion reduces blood viscosity and this in turn improves regional cerebral microvascular flow and oxygenation. It also increases intravascular volume and therefore cardiac output. Together, these effects result in an increase in regional cerebral blood flow and compensatory cerebral vasoconstriction in brain regions where autoregulation is intact, resulting in a reduction in ICP
- What is the importance of the primary and secondary brain injuries when managing an acute head injury?
Primary brain injury – injury that occurs at the time of the trauma. This can include brain contusion, skull fracture, haemorrhage or diffuse axonal injury.
Secondary brain injury is a potentially preventable and reversible injury occurring as a consequence of the pathophysiological evolution of the primary injury.
The importance is that a primary brain injury needs to be recognised, and once recognised the main objective of treatment is to prevent secondary brain injuries.
Minimising secondary brain injury is best achieved by avoiding periods of hypoxia or
hypotension. Thus maintaining adequate ventilation and cerebral perfusion is essential.
- What are the methods most commonly used for clinical assessment of a head injury?
Methods most commonly used for clinical assessment of a head injury are serial clinical observations, a thorough history and examination, CT head scan and the Westmead Post-traumatic Amnesia scale used to assess severity.
•Serial clinical observations include:
- Vital signs – 15 mins
- Pupillary reactions – 15 mins
- -> First sign of CN III palsy is ipsilateral dilated pupil
- GCS – 15 mins
GCS 14-15 = minor: mortality 0.1%
GCS 9-13 = moderate: mortality 10%
GCS <9 = severe: mortality 40% - Mental status
Orientation to person/place/ time
A full history is essential and should also include specific questions regarding:
- mechanism of injury
- any changes consciousness, and if there were any seizures, amnesia and confusion.
- associated symptoms- headache, vision change, vertigo, N/V
Examination should include:
- assessing for hard trauma; lacerations, bruising, open wounds and fractures
AND a full neurological examination.
All patients with moderate or severe head injury should have a CT head.
