By Q. Varek. Cardinal Stritch University.
The white blood cell count is 6 buy minocycline 50 mg overnight delivery,500 purchase minocycline 50 mg on line, with 80% polymorphonuclear cells and increased band forms order 50mg minocycline fast delivery. Because you practice in a region in which up to 30% of invasive Streptococcus pneu- moniae isolates show intermediate or high-grade resistance to penicillin minocycline 50 mg line, you are worried that this patient may be infected with a drug-resistant strain. Which of the following would be the most appropriate initial choice for antimicrobial therapy in this patient? When prescribing initial treatment for community- acquired pneumococcal pneumonia, a physician should be aware of both the regional prevalence of drug resistance and the typical patterns of antimicrobial cross-resistance. Of the choices given, only levofloxacin has a very low rate of cross-resistance. Because an alteration of penicillin-binding proteins is the usual mechanism of penicillin resist- ance in S. Vancomycin resistance remains exceedingly rare among S. A homeless 56-year-old man is admitted with progressive fever and right-sided chest pain. He describes how for 3 weeks he has had anorexia, fatigue, and cough productive of profuse purulent sputum with 7 INFECTIOUS DISEASE 71 occasional hemoptysis. Additional medical problems include a 60-pack-year history of cigarette smok- ing, chronic alcoholism, occasional injection drug use, and chronic hepatitis C infection. On physical examination, the patient appears cachectic and acutely ill and has a temper- ature of 101. He has numerous injection track marks on his extremities but no cyanosis, clubbing, or peripheral edema. The upper half of the right posteri- or chest is dull to percussion, and rhonchi are heard in the same region. A chest CT scan demonstrates opacification of the posterior segment of the right upper lobe, with a central fluid-filled and air-filled cavity. Gram stain demonstrates abundant polymor- phonuclear leukocytes; gram-positive cocci of various sizes appear as single organisms and in pairs and chains, and occasional gram-positive rods, gram-negative cocci, and gram-negative rods are present. Which of the following is the most likely diagnosis for this patient? Squamous cell lung cancer with cavitation and postobstructive pneumonia D. Wegener granulomatosis Key Concept/Objective: To know the clinical features of primary anaerobic lung abscess Each of the conditions listed can produce cavitary lung lesions. Tuberculosis would also be a key consideration, but the sputum Gram stain result precludes a diagnosis of tuber- culosis. Nevertheless, it would be reasonable to place this patient in respiratory isolation, perform PPD skin testing (without controls), and send sputum for acid-fast bacilli stain- ing and mycobacterial culture. Of the various histo- logic types of lung cancer, squamous cell tumors are the most likely to cavitate. Produc- tion of profuse sputum does not suggest obstruction, however. In injection drug users, sep- tic pulmonary embolism is a common complication of tricuspid valve endocarditis. A 68-year-old man with severe chronic obstructive pulmonary disease (COPD) (baseline FEV1, 800 ml) is admitted to the intensive care unit with acute respiratory failure and fever. His wife reports that he was in his usual state of debilitated health until 4 days ago, when he developed myalgias, fever, chills, and a headache. Two days before admission, he experienced increasing shortness of breath and cough, and he passed several watery bowel movements. Symptoms did not improve with increased use of albuterol, which was administered at home with a nebulizer. On the day of admission, he appeared con- fused and severely short of breath.
The MLF is found just system is too small to be identified 50 mg minocycline amex. The nuclei of the anterior to these nuclei 50 mg minocycline with visa, near the midline purchase minocycline 50 mg on line. Some of the reticular formation include the caudal portion of the pon- exiting fibers of CN VI may be seen as the nerve emerges tine reticular formation minocycline 50 mg sale, which also contributes to the pon- anteriorly, at the junction of the pons and medulla. CN VII: The motor neurons of the facial nerve The fourth ventricle is very large but often seems nucleus, supplying the muscles of facial expression, are smaller because the lobule of the cerebellar vermis, called located in the ventrolateral portion of the tegmentum. As the nodulus (part of the flocculonodular lobe, refer to explained, the fibers of CN VII form an internal loop over Figure 54), impinges upon its space. The MLF is found the abducens nucleus (see Figure 48). Also present is the actual section through this level of the pons. The intracerebellar (deep cerebel- Figure 6 and Figure 7). The auditory fibers synapse in the lar) nuclei are also found at this cross-sectional level and dorsal and ventral cochlear nuclei, which will be seen in are located within the white matter of the cerebellum the medulla in a section just below this level (see also (discussed with Figure 56A and Figure 56B). Superior 4th ventricle Lateral Cerebellar peduncles: Inferior Spinal t. Medial lemniscus Facial nerve (CN VII) Vestibulocochlear Trapezoid body nerve (CN VIII) Abducens nerve (CN VI) Superior olivary complex Cortico-spinal fibers Pontine nuclei FIGURE 66C: Brainstem Histology — Lower Pons © 2006 by Taylor & Francis Group, LLC 190 Atlas of Functional Neutoanatomy THE MEDULLA 67C). The fourth ventricle lies behind the tegmentum, separating the medulla from the cerebellum (see Figure FIGURE 67, FIGURE 67A, 20B). The roof of this (lower) part of the ventricle has choroid plexus (see Figure 21). CSF escapes from the FIGURE 67B, AND FIGURE 67C fourth ventricle via the various foramina located here, and then flows into the subarachnoid space, the cisterna magna This part of the brainstem has a different appearance from (see Figure 18 and Figure 21). They contain the cortico-spinal of the medulla, with the cerebellum attached. This speci- fibers that have descended from the motor areas of the men shows the principal identifying features of the cortex and now emerge as a distinct bundle (see Figure medulla, the pyramids ventrally on either side of the mid- 45 and Figure 48). Most of its fibers cross (decussate) at line and the more laterally placed inferior olivary nucleus, the lowermost part of the medulla. It is so large that line, are two dense structures, the medial lemniscus. The it forms a prominent bulge on the lateral surface of the other dense tract that is recognizable in this specimen is medulla (see Figure 6 and Figure 7). Its fibers relay to the the inferior cerebellar peduncle located at the outer pos- cerebellum (see Figure 55). Other tracts and cranial nerve The tegmentum is the area of the medulla that contains nuclei, including the reticular formation, are found in the the cranial nerve nuclei, the nuclei of the reticular forma- central region of the medulla, the tegmentum. The most promi- The cerebellum remains attached to the medulla, with nent nucleus of the reticular formation in this region is the prominent vermis and the large cerebellar hemi- the nucleus gigantocellularis (see Figure 42A and Figure spheres. The cerebellar lobe adjacent to the medulla is the 42B); the descending fibers form the lateral reticulo-spinal tonsil (see Figure 18; discussed with Figure 9B). The spinal trigeminal tract • Figure 67A: The upper medullary level typi- and nucleus, conveying the modalities of pain and tem- cally includes CN VIII (both parts) and its perature from the ipsilateral face and oral structures, is nuclei. The solitary nucleus • Figure 67B: This section through the mid- and tract, which subserve both taste and visceral afferents, medulla includes the nuclei of cranial nerves are likewise found in the medulla. The nerve has two nuclei along its course, the ventral and dorsal cochlear nuclei (see UPPER MEDULLA: Figure 8B). The auditory fibers synapse in these nuclei and then go on to the superior olivary complex in the lower CROSS-SECTION pons region. The crossing fibers are seen in the lowermost pontine region as the trapezoid body (see Figure 37 and This section has the characteristic features of the medul- Figure 40).
The left leg shows mild weakness and increased reflexes buy minocycline 50mg mastercard. On the basis of this patient’s history and symptoms order minocycline 50 mg overnight delivery, which of the following would be the most appropriate therapeutic regimen? Long-term glatiramer or interferon beta and short-term steroids Key Concept/Objective: To understand therapy for MS In MS buy minocycline 50 mg without a prescription, the management of acute relapses varies with the severity of the presenting symp- toms and signs cheap 50 mg minocycline overnight delivery. High-dose corticosteroid therapy is indicated for exacerbations that adversely affect the patient’s function. A short, tapering course of corticosteroids may be given afterward. In the past few years, three different medications that affect the long-term clinical course of MS have been approved: interferon beta-1b, interferon beta-1a, and glati- ramer acetate (previously known as copolymer-1). These drugs reduce the frequency of attacks and limit the accumulation of fixed lesions on MRI. In patients with relapsing- remitting MS, these agents may delay the accumulation of disability. The choice of which agent to use depends on the particular patient. Patients who are maintained on these ther- apies can expect an 18% to 50% reduction in attack frequency. Best responses with any of the available drugs appear to result from initiation of treatment relatively early in the dis- ease course. Mitoxantrone currently has a role for selected patients with very active disease; it is approved for the treatment of aggressive relapsing and secondary progressive MS. A 26-year-old woman is evaluated for decreased vision and eye pain. Her symptoms started 2 days ago with pain in her right eye with ocular movements. Over the past 24 hours, she has experienced a decrease in central vision in her right eye. Physical examination shows decreased central vision and pain on ocular movement of the right eye. There is an afferent pupil- lary defect on the right. MRIs of the brain and spinal cord are consistent with optic neuritis on the right; there are two white matter lesions in the periventricular area. On the basis of this patient’s presentation and MRI findings, which of the following statements is most accurate? The patient has MS and should be started on steroids and glatiramer B. The patient has optic neuritis; she is at significant risk for developing MS in the future 11 NEUROLOGY 25 C. The patient has optic neuritis; she is at no risk of progressing to MS in the future D. The patient has MS; she should be started on mitoxantrone Key Concept/Objective: To know the association between optic neuritis and MS Optic neuritis is an acute inflammatory optic neuropathy. The cardinal symptoms are uni- lateral vision loss and retrobulbar pain with eye movement. Treatment with intravenous methylprednisolone followed by oral prednisone hastens recovery of vision. Even without treatment, almost all patients begin to recover vision within 4 weeks. The relationship of optic neuritis to MS is controversial. Some regard optic neuritis as a distinct entity, but oth- ers consider it part of the clinical continuum of MS. More than half of all patients with MS have optic neuritis at some time during the course of disease.