CASE 5(Click here to go to the answers)
A 53-year-old man starts to experience bifrontal headaches. The headaches are relieved by aspirin, but they recur periodically over the next two weeks. The man and his wife begin to wonder what is going on because he has no previous history of persistent headaches. As a matter of fact, his health has been very good. He has never smoked, drinks only in moderation, and is not taking any medications. Nevertheless, the man's periodic headaches persist for another week, at which point he suddenly starts to have focal seizures with involuntary movement of the right side of his face and arm. His wife rushes him to the ER where, while awaiting treatment, he suffers a generalized seizure that is controlled with intravenous diazepam, phenytoin, and phenobarbital. The man's vital signs are T = 37ºC, P = 110/min, RR = 18/min, and BP = 140/80 mm Hg. On physical examination, he is sleepy and has a decreased attention span. He can move all of his extremities, although he moves his right arm less than his left. His left optic disk is slightly blurred, but there are no other remarkable physical findings. The ER physicians ask the man's wife about his medical history. She says that, aside from the headaches, his only recent complaint was a painfully sore tooth that resulted in an extraction and bridge work about five weeks ago.
Question 5.1: What is the differential?
Question 5.2: What tests should you do?
Question 5.3: What is your diagnosis?
Question 5.4: How should you treat this case?
Question 5.5: What was the source of the infection?
Question 5.6: What is the likely causative agent?
CASE 6(Click here to go to the answers)
A 48-year-old man owns a large corporate travel company and frequently travels throughout Europe, Asia, Africa, and South America. He is left-handed. On one of his many business trips, he notices the onset of right hand clumsiness, unsteady gait, forgetfulness, and a mild headache. These symptoms persist and occasionally interfere with the man's ability to carry out his professional activities. He is a little worried about this, but his business is at a very critical stage, so he adapts to the symptoms the best he can and continues to travel for another three weeks. By the time the man returns to the U.S. and seeks medical treatment from his regular physician, he has developed decreased vision and a mild pain his right eye, and he is finding it increasingly difficult to express himself verbally. His condition continues to deteriorate as his physician awaits the results of routine tests. Over the next 10 days, he becomes unable to sign his own checks and develops a distinct tremor in his right hand. Because of the alarmingly progressive nature of the man's disease, his physician then refers him to a clinic that specializes in neurological disorders.
The man's vital signs are normal. On neurologic examination, he is alert, attentive, and oriented to name, place, and time. He follows one-step commands well but has difficulty with multi-step commands. His speech is telegraphic, but comprehension seems intact. Object naming and writing of full sentences are severely impaired. Muscle tone is increased in the right arm and leg, and the man has a right-sided hyperreflexia. He has bilateral ankle clonus and a right extensor plantar response. He also has a right homonymous hemianopsia and right-sided weakness in an upper motor neuron distribution. The man exhibits a wide-based, right circumductive gait, with the right upper extremity flexed at the elbow and held across his chest. He also has nonpurposeful and nonrhythmic movements of the right arm superimposed on a lowamplitude rhythmic postural and kinetic tremor.
The man has no history of any prior medical illness and did not experience any prodromal or viral-like illness prior to the onset of his symptoms. He consumes about 2-3 ounces of alcohol daily, and he stopped smoking 12 years ago.
Question 6.1: What is your preliminary diagnosis?
Question 6.2: How can you confirm the diagnosis?
Question 6.3: How did the disease come about?
Question 6.4: What is the man's prognosis?
CASE 7(Click here to go to the answers)
It is 1954, and about 300 children from the same neighborhood in Chicago enjoy swimming and other activities. Over a three-week period, 17 of these children develop "flu-like" symptoms, with fevers up to 39.5ºC, sore throat, myalgias, headaches, and malaise. These symptoms persist for an average of 5 days, after which the victims begin to complain of stiff neck, markedly increased muscle pain, occasional muscle spasms, and elevated fever (to 41ºC). These symptoms are followed by flaccid paralysis that varies widely in its degree of severity. Some patients experience paralysis of only a few muscle groups (in one leg, for example), while others develop complete flaccid paralysis of all four extremities and are totally incapacitated. Four of the 17 victims eventually make full recoveries, but 8 of them recover with varying degrees of residual paralysis. Five of the victims experience a continuation of the illness, in which flaccid paralysis of the pharynx, vocal cord, and respiratory muscles develops. These victims are able to breathe only with the help of a mechanical device that provides external respiratory compression. All of them die within the next six months.
Fourteen of the 17 victims of this disease outbreak are boys, aged 12 to 17, all of whom are members of either the football or the soccer team at their respective schools. All of the victims who eventually died had tonsillectomies when they were younger, whereas only two of those who survived had undergone tonsillectomies. In a follow-up epidemiological study of the neighborhood, it was found that more than 50 children who used the pool experienced nonspecific flu-like symptoms during the same period in which the above cases developed, but their symptoms cleared up spontaneously within 1-3 days.
Question 7.1: What is your diagnosis?
Question 7.2: What is the causative agent?
Question 7.3: Why did the cases vary in severity?
Question 7.4: What is the pathogenic process?
Question 7.5: How is this disease transmitted?
Question 7.6: How is this disease prevented?
Question 7.7: How prevalent is this disease today?
CASE 8(Click here to go to the answers)
A 35-year-old nurse develops subcutaneous nodules across her head and arms, after which she begins to experience frequent headaches. The headaches slowly worsen over the next three weeks and are joined by occasional nausea and vomiting. One morning at work, she becomes slightly dizzy and thinks that her vision might be blurred. Shortly thereafter, she experiences a general seizure and is immediately transported to the ER. In the ER, her vital signs are normal, but she is somewhat confused. Her temporal arteries are not thickened or tender. She does not have a stiff neck, and Brudzinski's sign is negative. The general physical examination is unremarkable. The nurse manages to describe her headaches and other recent symptoms to the attending physician before suffering yet another generalized seizure. Her medical records are readily available and indicate that she has no history of neurological disorders. The attending physician notes that, about 10 years ago, she spent two years in Thailand as a Peace Corps volunteer.
Question 8.1: What tests should you perform?
Question 8.2: What is your preliminary diagnosis?
Question 8.3: How is the diagnosis confirmed?
Question 8.4: How is the disease acquired?
Question 8.5: How does the parasite reach the brain?
Question 8.6: How is this disease treated?
CASE 9(Click here to go to the answers)
A 67-year-old man who has been in generally good health begins to experience fever, headache, and malaise, along with persistent pain in the area of his left thorax. Four days later, a rash consisting of a broad band of erythematous maculopapules develops along the center of his left thorax. The maculopapules evolve into vesicles and pustules over the next 36 hrs. The vesicles have an erythematous base, are cloudy, and vary in size. The man continues to experience severe pain in the area where the rash is occurring, so he comes to your office to seek advice.
Question 9.1: What should you ask this man?
Question 9.2: What is the causative agent?
Question 9.3: How does the disease develop?
Question 9.4: Are there any specialized forms of this disease?
Question 9.5: How is the diagnosis confirmed?
Question 9.6: How should you treat this case?
CASE 10(Click here to go to the answers)
A 37-year-old homosexual man who has been active with multiple partners without taking precautions begins to experience fever and persistent headaches. Over the next two weeks, he develops mild nausea with occasional vomiting. He then starts to hallucinate and exhibit irrational behavior, at which point his friends bring him to the ER. Vital signs are normal, except for a mild fever (38.5ºC). The man is confused and disoriented. His visual fields appear to be reduced, he has a number of movement disorders, particularly on the left, and he is displaying signs of aphasia.
Question 10.1: What tests should you do?
Question 10.2: What is your diagnosis?
Question 10.3: How is the diagnosis confirmed?
Question 10.4: What is the pathogen's life cycle?
Question 10.5: How is this disease transmitted?
Question 10.6: How did the man's disease develop?
Question 10.7: How should you treat this case?