Cerebral abscess as a complication of cystic fibrosis

Neurological effects of respiratory dysfunction

The respiratory and the nervous systems are closely interconnected and are maintained in a fine balance. Central mechanisms maintain strict control of ventilation due to the high metabolic demands of brain which depends on a continuous supply of oxygenated blood along with glucose. Moreover, brain perfusion is highly sensitive to changes in the partial pressures of carbon dioxide and oxygen in blood, which in turn depend on respiratory function. Ventilatory control is strictly monitored and regulated by the central nervous system through central and peripheral chemoreceptors, baroreceptors, the cardiovascular system, and the autonomic nervous system. Disruption in this delicate control of respiratory function can have subtle to devastating neurological effects as a result of ensuing hypoxia or hypercapnia. In addition, pulmonary circulation receives entire cardiac output and this may act as a conduit to transmit infections and also for metastasis of malignancies to brain resulting in neurological dysfunction. Furthermore, many neurological paraneoplastic syndromes can have underlying lung malignancies resulting in respiratory dysfunction. It is essential to understand the underlying mechanisms and the resulting manifestations in order to prevent and effectively manage the many neurological effects of respiratory dysfunction. This chapter explores the various neurological effects of respiratory dysfunction with focus on their pathophysiology, etiologies, clinical features and long-term neurological sequelae.

The Streptococcus milleri group--an unrecognized cause of disease in cystic fibrosis: a case series and literature review

The "Streptococcus milleri" group (SMG) is increasingly recognized for their role in pyogenic infections including empyema and solid organ abscesses. However, SMG disease has rarely been identified in cystic fibrosis (CF). Inherent difficulties in both growing the organisms and distinguishing SMG from less virulent oropharyngeal viridans streptococci may have led to a decreased recognition of this as a CF pathogen. We report on six cases of SMG-related infection over a 4-year time-frame occurring within an adult CF clinic in Canada, and a further four cases identified through a literature review. SMG manifested disease as bronchopulmonary exacerbations in 7 of 10 patients, and 4 of 10 patients had extra-pulmonary dissemination of SMG infection. Noticeably, pulmonary exacerbations were frequently associated with atypically malodorous sputum. Furthermore, patients clinically responded to anti-microbial therapies with no anti-Pseudomonal activity. There was a consistent correlation of SMG disease and co-colonization with P. aeruginosa leading to speculation of polymicrobial interactions resulting in enhanced virulence. SMG deserves considerable attention as a potential pathogen within the airways of patients with CF.

Management of frontal sinus mucoceles with posterior table erosion in the pretransplant cystic fibrosis population

BACKGROUND

Chronic rhinosinusitis has been described as a universal finding in cystic fibrosis (CF). Much of the literature has focused on pediatric population with a relative paucity of data on adult CF patients. In this report, we review our experience with management of frontal sinus mucoceles with posterior table (PT) erosion diagnosed by imaging in asymptomatic adult CF patients presenting for pretransplant evaluation.

STUDY DESIGN

Retrospective chart analysis.

MATERIALS AND METHODS

Adult CF patients presenting with frontal sinus mucoceles from January 2003 to December 2005 comprised the focus of the study. Charts were reviewed for age, sex, clinical presentation, culture results, complications, and outcome.

RESULTS

Fifty-nine CF patients undergoing lung transplant evaluation were seen in the outpatient rhinology clinic. Among these, 3 patients presented with asymptomatic frontal sinus mucoceles with PT erosion. The average age was 28.7 years (range, 23-38 years) and male-female ratio was 1:2. Two patients were managed with computer-aided endoscopic frontal sinusotomy during the pretransplant period. In the third patient, surgery was performed post transplantation when the patient was clinically stable. Intraoperative cultures grew Pseudomonas aeruginosa in all cases. No intraoperative surgical complications were encountered. One patient required overnight ventilatory support and was extubated successfully after 24 hours. Endoscopic patency of the frontal sinusotomy was confirmed at mean follow-up of 12.7 months (range, 4-22 months).

CONCLUSIONS

This preliminary report describes asymptomatic frontal sinus mucoceles with PT erosion in CF patients presenting for transplant evaluation. A high index suspicion must be maintained to avoid an inordinate delay in diagnosis given the potential risk of intracranial complications with this clinical entity.

An intrasylvian "fibroma" in a child with cystic fibrosis: case report

OBJECTIVE AND IMPORTANCE

Intracranial fibrous tumors are uncommon during childhood. An unusual case of benign intrasylvian "fibroma" that has remained clinically and radiographically stable more than 3 years after a subtotal resection is described.

CLINICAL PRESENTATION

A 9-year-old girl with cystic fibrosis presented with new-onset focal seizures referable to a large calcified left sylvian fissure mass.

INTERVENTION

An open biopsy with subtotal resection of the lesion revealed a benign process characterized by exuberant fibrocollagenous tissue intermeshed with chronic inflammatory cells and foreign body giant cells, encompassing islands of gliotic brain tissue. Immunohistochemical analysis showed staining for epithelial membrane antigen and reticulin within some of the spindle cells, although the majority were nonreactive. The majority of tumor cells exhibited staining for laminin; CD34 staining was absent. Ultrastructural studies were also suggestive of a fibroblastic rather than a meningothelial origin of the lesion, with elongated cells separated by abundant extracellular collagen. Although dense adherence of the mass to the pial surface and the middle cerebral artery vessels precluded a complete resection, the patient remains seizure-free without anticonvulsant therapy more than 3 years postoperatively with no evidence of growth of the lesion.

CONCLUSION

The lesion in this patient bears morphological similarity to a rare group of tumors referred to as "intracerebral fibromas," although a variety of other rare mesenchymal neoplasms were also considered within the differential diagnosis. However, the absence of any definite neoplastic features, the finding of chronic inflammatory changes, and the lack of growth of the residual tumor during an extended follow-up interval indicate that the mass may represent either an extremely indolent neoplasm or a nonneoplastic process. The differential diagnosis of intracranial fibrous tumors is contrasted with that of the reported case.