TABLE IV-114 Risk Factors for Active Tuberculosis Among Persons Who Have Been Infected With Tubercle Bacilli 37 page

A. Acromegaly

B. Critical illness

C. HIV infection

D. Hypothyroidism

E. Vitamin B₁₂ deficiency

XI-54. A 50-year-old male complains of weakness and numbness in the hands for the last month. He describes paresthesias in the thumb and the index and middle fingers. The symptoms are worse at night. He also describes decreased grip strength bilaterally. He works as a mechanical engineer. The patient denies fevers, chills, or weight loss. The examination is notable for atrophy of the thenar eminences bilaterally and decreased sensation in a median nerve distribution. You consider the diagnosis of carpal tunnel syndrome. All the following are causes of carpal tunnel syndrome EXCEPT:

A. Amyloidosis

B. Chronic lymphocytic leukemia

C. Diabetes mellitus

D. Hypothyroidism

E. Rheumatoid arthritis

XI-55. A 27-year-old woman is diagnosed with Guillain-Barré syndrome after presenting with flaccid paralysis and sensory disturbance several weeks after a diarrheal illness. Which of the following bacteria have been implicated in cases of Guillain-Barré syndrome?

A. Bartonella henselae

B. Campylobacter jejuni

C. Escherichia coli

D. Proteus mirabilis

E. Tropheryma whippelii

XI-56. A 34-year-old female complains of weakness and double vision for the last 3 weeks. She has also noted a change in her speech, and her friends tell her that she is “more nasal.” She has noticed decreased exercise tolerance and difficulty lifting objects and getting out of a chair. The patient denies pain. The symptoms are worse at the end of the day and with repeated muscle use. You suspect myasthenia gravis. All the following are useful in the diagnosis of myasthenia gravis EXCEPT:

A. Acetylcholine receptor (AChR) antibodies

B. Edrophonium

C. Electrodiagnostic testing

D. Muscle-specific kinase (MuSK) antibodies

E. Voltage-gated calcium channel antibodies

XI-57. A 38-year-old female patient with facial and ocular weakness has just been diagnosed with myasthenia gravis. You intend to initiate therapy with anticholinesterase medications and glucocorticoids. All of the following tests are necessary before instituting this therapy EXCEPT:

A. MRI of mediastinum

B. Purified protein derivative skin test

C. Lumbar puncture

D. Pulmonary function tests

E. Thyroid-stimulating hormone

XI-58. All of the following lipid-lowering agents are associated with muscle toxicity EXCEPT:

A. Atorvastatin.

B. Ezetimibe.

C. Gemfibrozil.

D. Niacin.

E. All of the above are associated with muscle toxicity.

XI-59. All of the following endocrine conditions are associated with myopathy EXCEPT:

A. Hypothyroidism.

B. Hyperparathyroidism.

C. Hyperthyroidism.

D. Acromegaly.

E. All of the above are associated with myopathy.

XI-60. A 34-year-old woman seeks evaluation for weakness. She has noted tripping when walking, particularly in her left foot, for the past 2 years. She recently also began to drop things, once allowing a full cup of coffee to spill onto her legs. In this setting, she also feels as if the appearance of her face has changed over the course of many years, stating that she feels as if her face is becoming more hollow and

elongated, although she hasn’t lost any weight recently. She has not seen a physician in many years and has no past medical history. Her only medications are a multivitamin and calcium with vitamin D. Her family history is significant for similar symptoms of weakness in her brother who is 2 years older. Her mother, who is 58 years old, was diagnosed with mild weakness after her brother was evaluated, but is not symptomatic. On physical examination, the patient’s face appears long and narrow with wasting of the temporalis and masseter muscles. Her speech is mildly dysarthric, and the palate is high and arched. Strength is 4/5 in the intrinsic muscles of the hand, wrist extensors, and ankle dorsiflexors. After testing handgrip strength, you notice that there is a delayed relaxation of the muscles of the hand. What is the most likely diagnosis?

A. Acid maltase deficiency (Pompe’s disease)

B. Becker muscular dystrophy

C. Duchenne muscular dystrophy

D. Myotonic dystrophy

E. Nemaline myopathy

XI-61. An elevation in which of the following serum enzymes is the most sensitive indicator of myositis?

A. Aldolase

B. Creatinine kinase

C. Glutamic-oxaloacetic transaminase

D. Glutamate pyruvate transaminase

E. Lactate dehydrogenase

XI-62. A 64-year-old woman is evaluated for weakness. For several weeks she has had difficulty brushing her teeth and combing her hair. She has also noted a rash on her face. Examination is notable for a heliotrope rash and proximal muscle weakness. Serum creatine kinase (CK) is elevated and she is diagnosed with dermatomyositis. After evaluation by a rheumatologist, she is found to have anti-Jo-1 antibodies. She is also likely to have which of the following findings?

A. Ankylosing spondylitis

B. Inflammatory bowel disease

C. Interstitial lung disease

D. Primary biliary cirrhosis

E. Psoriasis

XI-63. A 63-year-old woman is evaluated for a rash on her eyes and fatigue for 1 month. She reports difficulty with arm and leg strength and constant fatigue, but no fevers or sweats. She also notes that she has a red discoloration around her eyes. She has hypothyroidism but is otherwise well. On examination she has a heliotrope rash and proximal muscle weakness. A diagnosis of dermatomyositis is made after demonstration of elevated serum creatinine kinase and confirmatory EMGs. Which of the following studies should be performed as well to look for associated conditions?

A. Mammogram

B. Serum antinuclear antibody measurement

C. Stool examination for ova and parasites

D. Thyroid-stimulating immunoglobulins

E. Titers of antibodies to varicella zoster

XI-64. You are seeing your patient with polymyositis for follow-up. He has been taking prednisone at high doses for 2 months, and you initiated mycophenolate mofetil at the last clinic visit for a steroid-sparing effect. He began a steroid taper 2 weeks ago. His symptoms were predominantly in the lower extremities and face, and he has improved considerably. He no longer needs a cane and his voice has returned to normal. Laboratory data show a creatine kinase (CK) of 1300 U/L, which is unchanged from 2 months ago. What is the most appropriate next step in this patient’s management?

A. Continue current management.

B. Continue high-dose steroids with no taper.

C. Switch mycophenolate to methotrexate.

D. Repeat muscle biopsy.

XI-65. A 45-year-old woman who is 6 months post–liver transplant is admitted to the hospital after two grand mal seizures in the last 45 minutes. For the last day she has complained about headache and confusion. Her medications include diltiazem, cyclosporine, prednisone, and mycophenolate mofetil. She is now awake but somnolent. Her vital signs are normal except a blood pressure of 150/90 mmHg. There is bilateral afferent pupillary defect, and she reports she cannot see out of either eye. Hearing is intact. There is no nuchal rigidity. Her cyclosporine level is therapeutic. The FLAIR image of her MRI is shown in Figure XI-65. Which of the following is the most likely diagnosis?

FIGURE XI-65

A. Acoustic neuroma

B. Calcineurin-inhibitor toxicity

C. Panhypopituitarism

D. Streptococcal meningitis

E. Tuberculous meningitis

XI-66. A 77-year-old man undergoes coronary artery bypass grafting for refractory angina and three-vessel disease. Prior to surgery he still worked as a classics professor at a university teaching a renowned course on Dante’s “Inferno.” One month after surgery, his cardiac status is normal and his exercise tolerance is better than presurgery. However, his wife reports that he seems depressed and is often confused. His short-term memory is poor and he exhibits no enthusiasm for teaching. He has no fever or night sweats. Current medications include lovastatin and lisinopril. His physical examination is normal except for poor performance on serial 7 subtraction and only recalling 1 or 3 objects at 15 minutes. Which of the following is the most likely diagnosis?

A. Multiple sclerosis

B. Post–cardiac bypass brain injury

C. Streptococcal meningitis

D. Variant Creutzfeldt-Jacob disease

E. West Nile virus encephalitis

XI-67. A 24-year-old man is recovering from ARDS due to severe influenza A infection. During his complicated 3-week course of respiratory failure, he was placed on high-frequency ventilation and prone positioning necessitating paralysis and heavy sedation. Passive splints were placed on his upper and lower extremities. He is now extubated and awake, requiring only nasal oxygen. While starting his physical therapy, it is noted that he has right footdrop and numbness on the lateral leg. Additional examination reveals a unilateral right motor defect in foot dorsiflexion with intact inversion. There is sensory loss of the lateral aspect of the leg below the knee extending to the dorsum of the foot. The rest of the neurologic examination of the right leg and foot appears normal. Which of the following is the most likely etiology of his defects?

A. Cauda equina syndrome

B. Femoral nerve injury

C. L4 radiculopathy

D. L5 radiculopathy

E. Peroneal nerve injury

XI-68. In the CDC diagnostic criteria for chronic fatigue syndrome, in addition to clearly delineated findings of fatigue, all of the following symptoms or findings must be concurrently present for at least 6 months EXCEPT:

A. Delusional disorder

B. Impaired memory or concentration

C. Muscle pain

D. Sore throat

E. Tender cervical or axillary lymph nodes

XI-69. Which of the following is a beneficial therapy for chronic fatigue syndrome?

A. Bupropion

B. Cognitive behavioral therapy

C. Doxycycline

D. Fluoxetine

E. Olanzapine

XI-70. A 26-year-old woman presents to the emergency department complaining of shortness of breath and chest pain. These symptoms began abruptly and became progressively worse over 10 minutes, prompting her to call 911. Over this same period, the patient describes feeling her heart pounding and states that she felt like she was dying. She feels lightheaded and dizzy. It is currently about 20 minutes since the onset of symptoms and the severity has abated, although she continues to feel not back to her baseline. She denies any immediate precipitating cause, although she has been under increased stress as her mother has been hospitalized recently with advanced breast cancer. She does not take any medications and has no medical history. She denies tobacco, alcohol, or drug use. On initial examination, she appears somewhat anxious and diaphoretic. Her initial vital signs show a heart rate of 108 beats/min, blood pressure 122/68 mmHg, and respiratory rate 20 breaths/min. She is afebrile. Her examination is normal. Her arterial blood gas shows a pH of 7.52, PaCO₂ of 28 mmHg, and PaO₂ of 116 mmHg. The ECG is normal as is a chest radiograph. What is the next best step in the management of this patient?

A. Initiate therapy with alprazolam 0.5 mg four times daily.

B. Initiate therapy with fluoxetine 20 mg daily.

C. Perform a CT pulmonary angiogram.

D. Reassure the patient and suggest medical and/or psychological therapy if symptoms recur on a
frequent basis.

E. Refer for cognitive behavioral therapy.

XI-71. All of the following antidepressant medications are correctly paired with their class of medication EXCEPT:

A. Duloxetine—Selective serotonin reuptake inhibitor

B. Fluoxetine—Selective serotonin reuptake inhibitor

C. Nortriptyline—Tricyclic antidepressant

D. Phenelzine—Monoamine oxidase inhibitor

E. Venlafaxine—Mixed norepinephrine/serotonin reuptake inhibitor and receptor blocker

XI-72. A 42-year-old woman seeks your advice regarding symptoms concerning for post-traumatic stress disorder. She was the victim of a home invasion 6 months previously where she was robbed and beaten by a man at gunpoint. She thought she was going to die and was hospitalized with multiple blunt force injuries including a broken nose and zygomatic arch. She now states that she is unable to be alone in her home and frequently awakens with dreams of the event. She is irritable with her husband and children and cries frequently. She has worsening insomnia and often stays awake most of the night watching out her window because she is afraid her assailant will return. She has begun drinking a bottle of wine nightly to help her fall asleep, although she notes that this has worsened her nightmares in the early

morning hours. You concur that post-traumatic stress disorder is likely. What treatment do you recommend for this patient?

A. Avoidance of alcohol

B. Cognitive behavioral therapy

C. Paroxetine 20 mg daily

D. Trazodone 50 mg nightly

E. All of the above

XI-73. A 36-year-old man is being treated with venlafaxine 150 mg twice daily for major depression. He has currently been on the medication for 4 months. After 2 months, his symptoms were inadequately controlled, necessitating an increase in the dose of venlafaxine from 75 mg twice daily. He has had one prior episode of major depression when he was 25. At that time, he was treated with fluoxetine 80 mg daily for 12 months, but found the sexual side effects difficult to tolerate. He asks when he can safely discontinue his medication. What is your advice to the patient?

A. He should continue on the medication indefinitely as his depression is likely to recur.

B. The current medication should be continued for a minimum of 6–9 months following control of
his symptoms.

C. The medication can be discontinued safely if he establishes a relationship with a psychotherapist
who will monitor his progress and symptoms.

D. The medication can be discontinued safely now as his symptoms are well controlled.

E. The medication should be switched to fluoxetine to complete 12 months of therapy, as this was
previously effective for him.

XI-74. Which of the following will lead to a faster rate of absorption of alcohol from the gut into the blood?

A. Coadministration with a carbonated beverage

B. Concentration of alcohol of more than 20% by volume

C. Concurrent intake of a high-carbohydrate meal

D. Concurrent intake of a high-fat meal

E. Concurrent intake of a high-protein meal

XI-75. Which of the following best reflects the effect of alcohol on neurotransmitters in the brain?

A. Decreases dopamine activity

B. Decreases serotonin activity

C. Increases γ-aminobutyric acid activity

D. Stimulates muscarinic acetylcholine receptors

E. Stimulates N-methyl-D-aspartate excitatory glutamate receptors

XI-76. In an individual without any prior history of alcohol intake, what serum concentration of ethanol (in grams per deciliter) would likely result in death?

A. 0.02

B. 0.08

C. 0.28

D. 0.40

E. 0.60

XI-77. All of the following statements regarding the epidemiology and genetics of alcoholism are true EXCEPT:

A. Among individuals who have demonstrated alcohol abuse, about 10% will develop true alcohol
dependence.

B. Approximately 60% of the risk for alcohol abuse disorders is attributed to genetics.

C. Children of alcoholics have a 10-fold higher risk of alcohol abuse and dependence.

D. The presence of a mutation of aldehyde dehydrogenase that results in intense flushing with
alcohol consumption confers a decreased risk of alcohol dependence.

E. The lifetime risk of alcohol dependence in most Western countries is about 10–15% for men and
5–8% for women.

XI-78. A 42-year-old man with alcohol dependence is admitted to the hospital for acute pancreatitis. Upon admission, he has an abdominal CT scan that shows edema without necrosis or hemorrhage of the pancreas. He is treated with IV fluids with dextrose, multivitamins, thiamine 50 mg daily, pain control, and bowel rest. He typically drinks 24 12-ounce beers daily. Forty-eight hours after admission, you are called because the patient is febrile and combative with the nursing staff. His vital signs demonstrate a heart rate of 132 beats/min, blood pressure of 184/96 mmHg, respiratory rate of 32 breaths/min, temperature of 38.7°C (101.7°F), and oxygen saturation of 94% on room air. He is agitated, diaphoretic, and pacing his room. He is oriented to person only. His neurologic examination appears non-focal, although he does not cooperate. He is tremulous. What is the next step in the management of this patient?

A. Administer a bolus of 1 L of normal saline and thiamine 100 mg IV.

B. Administer diazepam 10–20 mg IV followed by bolus doses of 5–10 mg as needed until the
patient is calm but able to be aroused.

C. Perform an emergent head CT.

D. Perform two peripheral blood cultures and begin treatment with imipenem 1 g IV every 8 hours.

E. Place the patient in four-point restraints and treat with haloperidol 5 mg IV.

XI-79. A 48-year-old woman is recovering from alcohol dependence and requests medication to help prevent relapse. She has a medical history of stroke occurring during a hypertensive crisis. Which of the following medications could be considered?

A. Acamprosate

B. Disulfiram

C. Naltrexone

D. A and C

E. All of the above

XI-80. What is the most common initial illicit drug of abuse among U.S. adolescents?

A. Benzodiazepines

B. Heroin

C. Marijuana

D. Methamphetamines

E. Prescription narcotics

XI-81. A 32-year-old woman is admitted to the hospital for drainage and treatment of a soft tissue abscess of her left forearm. She uses IV heroin on a daily basis, often spending $100 or more per day on drugs. Upon admission, she has a 4 × 2-cm fluctuant mass in the left forearm associated with fevers to 39.3°C (102.7°F) and tachycardia. The abscess is drained and packed, and the patient is initiated on therapy with IV clindamycin. About 10 hours after admission, you are called to the patient’s bedside for a change in the patient’s condition. Yo u are suspecting narcotic withdrawal. All of the following symptoms are consistent with this diagnosis EXCEPT:

A. Hyperthermia

B. Hypotension

C. Piloerection

D. Sweating

E. Vomiting

XI-82. A 24-year-old man is brought to the emergency department by emergency medical services (EMS) about 2 hours after an intentional overdose of sustained-release oxycodone that was taken in conjunction with alcohol. Upon arrival at the scene, emergency medical technicians found an empty bottle of sustained-release oxycodone tablets with a dose of 20 mg. It is unknown how many pills the patient ingested, but the prescription was written for 60 tablets. The patient was unresponsive with a respiratory rate of 4 breaths/min, blood pressure of 80/56 mmHg, heart rate of 65 beats/min, and oxygen saturation of 86% on room air. The patient was intubated in the field and naloxone 2 mg IM was administered. He is currently intubated and unresponsive without spontaneous respiration above the set ventilator rate. His blood pressure is 82/50 mmHg and heart rate is 70 beats/min. Which of the following is most appropriate at the present time in the evaluation and treatment of this patient?

A. Activated charcoal

B. IV saline bolus 1 L followed by repeated 500–1000 mL boluses to maintain adequate blood
pressure

C. Naloxone continuous infusion at a rate of 0.4 mg/h

D. Urine drug screen, acetaminophen levels, and blood alcohol content

E. All of the above

XI-83. Which of the following statements is TRUE with regard to the chronic effects of marijuana use?

A. Chronic use of marijuana is associated with low testosterone levels.

B. Chronic use of marijuana is the primary cause of amotivational syndrome.

C. Marijuana use is associated with an increased risk of psychotic symptoms in individuals with a
past history of schizophrenia.

D. Physical and psychological tolerance does not develop in chronic users of marijuana.

E. There is no withdrawal syndrome associated with cessation of marijuana use. XI-84. All of the following malignancies are associated with cigarette smoking EXCEPT:

A. Acute myeloid leukemia

B. Bladder

C. Cervix

D. Pancreas

E. Postmenopausal breast cancer

XI-85. A 42-year-old woman seeks advice from you regarding smoking cessation. She began smoking at age 15. On average, she has smoked about 1.5 packs of tobacco daily and is currently smoking 1 pack daily. She was able to successfully quit for a period of 8 months when she was pregnant with her child at the age of 28, but quickly began smoking again shortly after the baby’s birth. Her past medical history is significant for depression, but she is not currently on any medication. She does admit to ongoing symptoms of depression that contribute to her perceived need for ongoing cigarette use. Which of the following would you recommend for this patient?

A. Bupropion titrated to a dose of 150 mg twice daily

B. Bupropion titrated to a dose of 150 mg twice daily in combination with nicotine replacement
therapy

C. In-office counseling alone with a negotiated quit date

D. Varenicline titrated to a dose of 1 mg twice daily

E. Varenicline titrated to a dose of 1 mg twice daily in combination with nicotine replacement
therapy

XI-86. What percentage of cigarette smokers will die prematurely if they are unable to quit?

A. 2%

B. 10%

C. 25%

D. 40%

E. 70%

XI-87. You are counseling your patient on the need to quit smoking cigarettes. She has been smoking for over two decades and wants to quit in order to avoid the harmful physical effects of smoking. Wanting to take “baby steps,” she has switched to low-tar, low-nicotine cigarettes. Which of the following statements is TRUE about the potential benefit of switching to these low-yield cigarettes?

A. Fewer smoking-drug interactions are found among smokers of low-yield cigarettes.

B. Most smokers inhale the same amount of nicotine and tar even if they switch to low-yield
cigarettes.

C. Smokers of low-yield cigarettes tend to inhale less deeply and smoke fewer cigarettes daily.

D. Smoking low-yield cigarettes decreases the harmful cardiovascular effects of cigarette smoking.

E. Smoking low-yield cigarettes is a reasonable alternative to complete smoking cessation for
chronic smokers.

ANSWER

XI-1. The answer is D. (Chap. 366) Channelopathies, disorders of ion channels that lead to disease, are a growing mechanism to explain a number of neurologic diseases. Most are caused by a mutation in the ion channel gene or by autoimmune alteration of ion channel proteins. Some forms of epilepsy, including benign neonatal familial convulsions and generalized epilepsy with febrile convulsions, are associated with genetic abnormalities of sodium or potassium channels. Familial hemiplegic migraines are associated with genetic abnormalities in sodium and calcium channels. Spinocerebellar ataxia and other ataxias are associated with genetic abnormalities in potassium or calcium channels. Lambert-Eaton syndrome is an example of autoimmune-related abnormalities in calcium channel function. Parkinson’s disease is the classic example of neurotransmitter system–mediated disease.

XI-2. The answer is C. (Chap. 366) Synaptic neurotransmission is the predominant mechanism for neuronal communication. Therefore, it is not surprising that dysfunction with any step in the presynaptic synthesis, vesicular storage, and synaptic cleft release, and receptor binding in the postsynaptic cell may be associated with disease. Neurotransmitters bind to specific receptors that are either ionotropic or metabotropic. Functions related to ionotropic receptors are generally fast (<1 millisecond) and metabotropic receptors are more prolonged. Antibodies to the acetylcholine receptors or motor neuron calcium channels cause myasthenia gravis and Lambert-Eaton syndrome, respectively. Parkinson’s syndrome is related to selective cell death in the nigrostriatal dopamine pathway. Stiff-person syndrome is related to antibodies to glutamic acid decarboxylase, the bio-synthetic pathway for GABA. Orthostatic tachycardia syndrome is related to mutations in the norepinephrine transporter. Abnormalities with serotonin neurotransmitter function are implicated in mood disorders, migraine pain pathways, and somatic pain pathways.

XI-3 and XI-4. The answers are D and D, respectively. (Chap. 367) The ability to perform a thorough neurologic examination is an important skill for all internists to master. A careful neurologic examination can localize the site of the lesion and is important in directing further workup. The components of the neurologic examination include mental status, cranial nerves, motor, sensory, gait, and coordination. The motor examination is further characterized by appearance, tone, strength, and reflexes. Pronator drift is a useful tool for determining if upper extremity weakness is present. In this test, an individual is asked to stand with both arms fully extended and parallel to the floor while closing his or her eyes. If the arms flex at the elbows or fingers or there is pronation of the forearm, this is considered a positive test. Other tests of motor strength include tests of maximal effort in a specific muscle or muscle group. Most commonly this type of strength testing is graded from 0 (no movement) to 5 (full power) with varying degrees of weakness noted against resistance. However, many individuals find it more practical to use qualitative grading of strength, such as paralysis, severe weakness, moderate weakness, mild weakness, or full strength.

Babinski sign is a sign of upper motor neuron disease above the level of the S1 vertebra and is characterized by paradoxical extension of the great toe with fanning and extension of the other toes as well. Dysdiadochokinesis refers to the inability to perform rapid alternating movements and is a sign of cerebellar disease. Lhermitte symptom causes electric shock–like sensations in the extremities associated with neck flexion. It has many causes including cervical spondylosis and multiple sclerosis.

Romberg sign is performed with an individual standing with feet together and arms at the side. The individual is then asked to close his or her eyes. If the individual begins to sway or fall, this is considered a positive test and is a sign of abnormal proprioception.

XI-5. The answer is C. (Chap. 367) This patient likely has metastatic disease to the cervical spinal cord. The patient’s symptoms are bilateral with sparing of the cranial nerves and normal mental status, localizing the lesion below the level of the brainstem and cerebrum. The patient demonstrates mixed upper and lower motor neuron signs with decreased sphincter tone and a positive Babinski sign, placing the lesion at the level of the spinal cord. As the weakness is involving both the arms and legs, this would indicate a lesion in the lower cervical or upper thoracic spine. Symptoms of abnormalities at the level of the neuromuscular junction include bilateral weakness that can include the face having normal sensation.

XI-6. The answer is C. (Chap. 368) Appropriate and timely evaluation is needed to determine if a subarachnoid hemorrhage is present as it can be rapidly fatal if undetected. The procedure of choice for initial diagnosis is a CT of the head without IV contrast. On the CT, blood in the subarachnoid space would appear whiter compared to the surrounding brain tissue. The CT of the head is most sensitive when it is performed shortly after the onset of symptoms, but declines over several hours. It can also demonstrate the presence of mass effect and midline shift, factors that increase the severity of the underlying hemorrhage. In the situation where the CT head is negative but clinical suspicion is high, a lumbar puncture can be performed. This may demonstrate increased numbers of red blood cells that do not clear with successive aliquots of cerebrospinal fluid. If the lumbar puncture is performed more than 12 hours after a small subarachnoid hemorrhage, then the red blood cells may begin to decompose, leading to xanthochromia—a yellow to pink coloration of cerebrospinal fluid that can be measured spectrographically. A basic CT of the head with IV contrast is rarely useful in subarachnoid hemorrhage, as the brightness of the contrast material may make it difficult to identify blood in the subarachnoid space. However, a CT angiography that is performed with IV contrast can be useful in identifying the aneurismal vessel leading to the bleeding. Classic angiography is a more direct way to visualize the anatomy of the cranial vasculature and is now often combined with interventional procedures to coiling a bleeding vessel. Transcranial Doppler ultrasound is a test that measures the velocity of blood flow through the cranial vasculature. It is used in some centers following subarachnoid hemorrhage to assess for the development of vasospasm, which can worsen ischemia leading to increased damage to brain tissue following subarachnoid hemorrhage.

Date: 2016-04-22; view: 656