Chapter 51. Principle of Neurointensive Care

Question 1

Question 51-1: 
A 65-year-old man with myasthenia presents with severe weakness and is diagnosed as having myasthenic crisis. He requires intubation and is placed on mechanical ventilation. He was being treated with pyridostigmine but no other medications for the myasthenia. Which would be the best approach to immune modulation? 
A.  Corticosteroids 
B.  Plasma exchange 
C.  Azathioprine 
D.  Thymectomy

Answer 1

Answer 51-1: B.
When a patient presents with acute
myasthenic crisis, immune treatment with
plasma exchange or intravenous
immunoglobulin is appropriate. Azathioprine
takes too long to work in this setting.
Corticosteroids are a cornerstone treatment for
management of myasthenia, but patients may
become weaker before they get stronger, and
in this setting corticosteroids are ordered after
initiation of the plasma exchange or
immunoglobulin. Thymectomy, also takes
months for strengthening to occur. (p958)

Question 2

Question 51-2:
Myasthenic crisis, such as described above, can be precipitated. Which of the following can be precipitating factors?
1. Botox administration
2. Propranolol
3. Respiratory infection
4. Corticosteroids
Select: A = 1,2, 3. R = 1,3. C = 2.4. D = 4 only. E = All

Answer 2

Answer 51-2: E.
All oftbese can precipitate myasthenic crisis.
Corticosteroids are a treatment of MG, but
with acute administration can precipitate
crisis. (P958)

Question 3

Question 51-3:
Which of the following is correct management of blood pressure in patients with spontaneous intracranial hemorrage?
A. Mean arterial blood pressure of greater than 100 should be treated with antihypertensives
B. Cerebral perfusion pressure should be kept below 70 mm Hg
C. Aggressive hydration is required as part of routine management
D. Mean arterial blood pressure greater than 130 mm Hg should be treated with intravenous antihypertensives

Answer 3

Answer 51-3: D.
Mean arterial blood pressure increase may
produce rebleed with increased mass effect of
the intracranial hemorrhage. However,
overcorrection of the blood pressure should be
avoided, since this may affect cerebral
perfusion pressure. Aggressive hydration is
commonly performed for patients with stroke
including subarachnoid hemorrhage, but
iotraparenchymal hemorrhage is an exception.
(p958)

Question 4

Question 51-4:
Which of the following statements is true regarding management of a patient with subarachnoid hemorrhage?
A. Aggressive fluid hydration is contraindicated because of the potential effect on blood pressure
B. Systolic blood pressure should be kept below 160 mm Hg
C. Vasospasm usually occurs within the first three days of the subarachnoid hemorrhage, so preventative management is not needed after this time
D. Seizures are rare in patients with SAH, so preventative therapy is not needed

Answer 4

Answer 51-4: B.
Systolic blood pressure should be kept below
160 mm Hg. Vasospasm typically occurs after
three days, so preventative therapy is required.
Aggressive fluid hydration is given in patients
with SAH to try to avoid vasospasm. Seizures
develop in about 26% of patients with SAH,
so preventative therapy is commonly used.
(p958)

Question 5

Question 51-5:
A 75-year-old female presents with cerebral infarction with markedly elevated blood pressure, averaging 200/105 in the emergency department. CT shows no acute changes. The stroke was observed to occur two hours ago. Which of the following would be the best approach to management of the blood
pressure?
A. Administration of labetalol intravenously
B. Administration of labetalol orally
C. Administration of nitroprusside intravenously
D. No treatment

Answer 5

Answer 51-5: D.
No treatment is indicated for blood pressure of
200/ I 05 in a patient with ischemic stroke. Reduction of pressure can impair cerebral
circulation and exacerbate the infarction.
(p956)

Question 6

Question 51-6:
Which of the following is NOT a typical use for transcranial doppler ultrasonography?
A. Monitoring for vasospasm after subarachnoid hemorrhage
B. monitoring of intracranial vessel patency after infarction
C. Identification of aneurysm at the circle of Willis
D. Detection of hyperemia after head injury

Answer 6

Answer 51-6: C.
Aneurysms are typically visualized by CT,
MRl, and angiography rather than TCD. TeD
is used in the leu especially for monitoring of
vessel patency after cerebral infarction and for
monitoring of vasospasm in patients with
SAH. Head injurj-induced hyperemia can also
be monitored. (p946)

Question 7

Question 51-7:
A patient with COPD exacerbation is intubated and mechanically ventilated. The course is stormy and the patient develops sepsis syndrome, requiring treatment with multiple antibiotics. Laboratory studies show increased LFTs and ammonia. Which are the most likely possibilities for altered mental status?
1. Herpetic encephalitis
2. CNS spread on infection
3. Creutzfeldt-Jakob disease
4. Hepatic encephalopathy
Select: A = 1, 2, 3. B = 1, 3. C = 2, 4. D = 4 only. E = All

Answer 7

Answer 51-7: C.
Spread of infection to the meninges and brain
is uncommon, but is a real possibility in
patients with sepsis. Herpetic encephalitis and
cm are remote possibilities. Hepatic
encephaiopathy also has to be considered,
especially with multiple antibiotics. In a
patient with COPD and ventilatory failure,
anoxic. encephalopathy would also have to be
considered, but there is no history here of an
acute anoxic event. (P952)

Question 8

Question 51-8:
In the patient described above, CT and CSF were essentially normal. EEG shows triphasic waves. Which is the most likely diagnosis?
A. Herpes encephalitis
B. CJD
c. Hepatic encephalopathy most likely from medications
D. Anoxic encephalopathy

Answer 8

Answer 51-8: C.
The combination of encephalopathy, increased
LFTs, increased munonia, and triphasic
waves on EEG suggests hepatic
encephalopathy. While this might be
secondary to multi organ failure from the
sepsis syndrome, the effect ofmulripk
anuoiotics would be more likely, depalding
on the specific agentS used. (p952)

Question 9

Question 51-9:
A patient with Guillain-Barre syndrome develops severe hyponatremia. Which is the most likely cause?
A. SIADH
B. Diabetes insipidus
C. Excessive intravenous fluid replacement
D. Inadequate nutritional supplementation

Answer 9

Answer 51-9: A.
Syndrome of inappropriate antidiuretic
hormone production is commonly seen in the
neurological ICU, and can be caused by a
variety of disorders, but some of the most
important are subarachnoid hemorrhage,
massive infarction, intracerebral hemonbage,
Guillain-Barre syndrome, and other injuries.
The serum sodium is decreased and is treated
with water restriction. SIADH must be
differentiated from cerebral salt wasting
which requires fluid therapy rather than
restriction. (p963)

Question 10

Question 51-10: 
Fluids are routinely given to patients with acute ischemic stroke especially when acutely hypotensive. Which is the best fluid for this replacement? 
A.  D5W 
B.  D5NS 
C.  LR 
D. 0.9% NaCI

Answer 10

Answer 51-10: D.
Patients who are hypotensive following stroke
are typically treated with normal saline, and
aggressive fluid replacement is used.
Hypotonic solutions and dextrose-containing
solutions can exacerbate cerebral edema.
(p955)