Neurodevelopmental and growth impairment among extremely low-birth-weight infants with neonatal infection

CONTEXT

Neonatal infections are frequent complications of extremely low-birth-weight (ELBW) infants receiving intensive care.

OBJECTIVE

To determine if neonatal infections in ELBW infants are associated with increased risks of adverse neurodevelopmental and growth sequelae in early childhood.

DESIGN, SETTING, AND PARTICIPANTS

Infants weighing 401 to 1000 g at birth (born in 1993-2001) were enrolled in a prospectively collected very low-birth-weight registry at academic medical centers participating in the National Institute of Child Health and Human Development Neonatal Research Network. Neurodevelopmental and growth outcomes were assessed at a comprehensive follow-up visit at 18 to 22 months of corrected gestational age and compared by infection group. Eighty percent of survivors completed the follow-up visit and 6093 infants were studied. Registry data were used to classify infants by type of infection: uninfected (n = 2161), clinical infection alone (n = 1538), sepsis (n = 1922), sepsis and necrotizing enterocolitis (n = 279), or meningitis with or without sepsis (n = 193).

MAIN OUTCOME MEASURES

Cognitive and neuromotor development, neurologic status, vision and hearing, and growth (weight, length, and head circumference) were assessed at follow-up.

RESULTS

The majority of ELBW survivors (65%) had at least 1 infection during their hospitalization after birth. Compared with uninfected infants, those in each of the 4 infection groups were significantly more likely to have adverse neurodevelopmental outcomes at follow-up, including cerebral palsy (range of significant odds ratios [ORs], 1.4-1.7), low Bayley Scales of Infant Development II scores on the mental development index (ORs, 1.3-1.6) and psychomotor development index (ORs, 1.5-2.4), and vision impairment (ORs, 1.3-2.2). Infection in the neonatal period was also associated with impaired head growth, a known predictor of poor neurodevelopmental outcome.

CONCLUSIONS

This large cohort study suggests that neonatal infections among ELBW infants are associated with poor neurodevelopmental and growth outcomes in early childhood. Additional studies are needed to elucidate the pathogenesis of brain injury in infants with infection so that novel interventions to improve these outcomes can be explored.

Dexamethasone therapy for bacterial meningitis. Results of two double-blind, placebo-controlled trials

We enrolled 200 infants and older children with bacterial meningitis in two prospective double-blind, placebo-controlled trials to evaluate the efficacy of dexamethasone therapy in addition to either cefuroxime (Study 1) or ceftriaxone (Study 2). Altogether, 98 patients received placebo and 102 received dexamethasone (0.15 mg per kilogram of body weight every six hours for four days). At the beginning of therapy, the clinical and demographic characteristics of the patients in the treatment groups were comparable. The mean increase in the cerebrospinal fluid concentration of glucose and the decreases in lactate and protein levels after 24 hours of therapy were significantly greater in those who received dexamethasone than in those who received placebo (glucose, 2.0 vs. 0.4 mmol per liter [36.0 vs. 6.9 mg per deciliter], P less than 0.001; lactate, 4.0 vs. 2.1 mmol per liter [38.3 vs. 19.8 mg per deciliter], P less than 0.001; and protein, 0.64 vs. 0.25 g per liter [64.0 vs. 25.3 mg per deciliter], P less than 0.05). One patient in the placebo group in Study 1 died. As compared with those who received placebo, the patients who received dexamethasone became afebrile earlier (1.6 vs. 5.0 days; P less than 0.001) and were less likely to acquire moderate or more severe bilateral sensorineural hearing loss (15.5 vs. 3.3 percent; P less than 0.01). Twelve patients in the two placebo groups (14 percent) had severe or profound bilateral hearing loss requiring the use of a hearing aid, as compared with 1 (1 percent) in the two dexamethasone groups (P less than 0.001). We conclude that dexamethasone is beneficial in the treatment of infants and children with bacterial meningitis, particularly in preventing deafness.

Neonatal candidiasis among extremely low birth weight infants: risk factors, mortality rates, and neurodevelopmental outcomes at 18 to 22 months

BACKGROUND

Neonatal candidiasis is associated with substantial morbidity and mortality rates. Neurodevelopmental follow-up data for a large multicenter cohort have not been reported.

METHODS

Data were collected prospectively for neonates born at <1000 g at National Institute of Child Health and Human Development-sponsored Neonatal Research Network sites between September 1, 1998, and December 31, 2001. Uniform follow-up evaluations, including assessments of mental and motor development with the Bayley Scales of Infant Development II, were completed for all survivors at corrected ages of 18 to 22 months. We evaluated risk factors for the development of neonatal candidiasis, responses to antifungal therapy, and the association between candidiasis and subsequent morbidity and death.

RESULTS

The cohort consisted of 4579 infants; 320 of 4579 (7%) developed candidiasis; 307 of 320 had Candida isolated from blood, 27 of 320 had Candida isolated from cerebrospinal fluid, and 13 (48%) of 27 of those with meningitis had negative blood cultures. In multivariate analysis of risk factors on day of life 3, birth weight, cephalosporins, gender, and lack of enteral feeding were associated with development of candidiasis. After diagnosis, most neonates had multiple positive cultures despite antifungal therapy, and 10% of neonates had candidemia for > or =14 days. Death or neurodevelopmental impairment (NDI) was observed for 73% of extremely low birth weight infants who developed candidiasis. Death and NDI rates were greater for infants who had delayed removal or replacement of central catheters (>1 day after initiation of antifungal therapy), compared with infants whose catheters were removed or replaced promptly.

CONCLUSIONS

Blood cultures were negative for approximately one half of the infants with Candida meningitis. Persistent candidiasis was common. Delayed catheter removal was associated with increased death and NDI rates.

Neurologic manifestations in sarcoidosis: review of the literature, with a report of 23 cases

Nervous system involvement by sarcoidosis has been considered rare, yet more than 400 cases have been reported. We present 23 additional cases here, including 14 with autopsies, and we review the literature. The overall frequency of neurologic involvement is 5%. Patients usually have other stigmata of sarcoidosis; however, neurologic dysfunction is frequently the presenting finding. The protean manifestations of central nervous system (CNS) involvement usually occur in the early phase of the disease, while those of peripheral nervous system and skeletal muscle involvement are characteristically seen in the chronic stages. Basal granulomatous meningitis causes most of the CNS manifestations either by infiltration or compression of adjacent structures. Steroids are the mainstay of therapy, and the overall response is quite variable. The course is also variable, being transient in some and chronic in others. The prognosis is better with peripheral than with central nervous system involvement.

Hydrocephalus in children

Hydrocephalus is a common disorder of cerebral spinal fluid (CSF) physiology resulting in abnormal expansion of the cerebral ventricles. Infants commonly present with progressive macrocephaly whereas children older than 2 years generally present with signs and symptoms of intracranial hypertension. The classic understanding of hydrocephalus as the result of obstruction to bulk flow of CSF is evolving to models that incorporate dysfunctional cerebral pulsations, brain compliance, and newly characterised water-transport mechanisms. Hydrocephalus has many causes. Congenital hydrocephalus, most commonly involving aqueduct stenosis, has been linked to genes that regulate brain growth and development. Hydrocephalus can also be acquired, mostly from pathological processes that affect ventricular outflow, subarachnoid space function, or cerebral venous compliance. Treatment options include shunt and endoscopic approaches, which should be individualised to the child. The long-term outcome for children that have received treatment for hydrocephalus varies. Advances in brain imaging, technology, and understanding of the pathophysiology should ultimately lead to improved treatment of the disorder.

The beneficial effects of early dexamethasone administration in infants and children with bacterial meningitis

BACKGROUND

In experimental models of meningitis and in children with meningitis, dexamethasone has been shown to reduce meningeal inflammation and to improve the outcome of disease.

METHODS

We conducted a placebo-controlled, double-blind trial of dexamethasone therapy in 101 infants and children admitted to the National Children's Hospital, San José, Costa Rica, who had culture-proved bacterial meningitis or clinical signs of meningitis and findings characteristic of bacterial infection on examination of the cerebrospinal fluid. The patients were randomly assigned to receive either dexamethasone and cefotaxime (n = 52) or cefotaxime plus placebo (n = 49). Dexamethasone (0.15 mg per kilogram of body weight) was given 15 to 20 minutes before the first dose of cefotaxime and was continued every 6 hours thereafter for four days.

RESULTS

The demographic, clinical, and laboratory profiles were similar for the patients in the two treatment groups. By 12 hours after the beginning of therapy, the mean opening cerebrospinal pressure and the estimated cerebral perfusion pressure had improved significantly in the dexamethasone-treated children but worsened in the children treated only with cefotaxime (controls). At 12 hours meningeal inflammation and the concentrations of two cytokines (tumor necrosis factor alpha and platelet-activating factor) in the cerebrospinal fluid had decreased in the dexamethasone-treated children, whereas in the controls the inflammatory response in the cerebrospinal fluid had increased. At 24 hours the clinical condition and mean prognostic score were significantly better among those treated with dexamethasone than among the controls. At follow-up examination after a mean of 15 months, 7 of the surviving 51 dexamethasone-treated children (14 percent) and 18 of 48 surviving controls (38 percent) had one or more neurologic or audiologic sequelae (P = 0.007); the relative risk of sequelae for a child receiving placebo as compared with a child receiving dexamethasone was 3.8 (95 percent confidence interval, 1.3 to 11.5).

CONCLUSIONS

The results of this study, in which dexamethasone administration began before the initiation of cefotaxime therapy, provide additional evidence of a beneficial effect of dexamethasone therapy in infants and children with bacterial meningitis.

Meningitis caused by Streptococcus suis in humans

Between 1968 and 1984, 30 strains of Streptococcus suis causing meningitis were isolated in the Netherlands. Twenty-eight strains were type 2, one was type 4, and one was untypable. The average age of the patients infected with these strains was 49 years (range, 21-76 years); the male-to-female ratio was 6.5. Twenty-five patients (83%) were employed in the pork industry. Two patients (7%) died. In seven cases (23%), predisposing factors were identified. The most frequent sequela was hearing loss (54% of surviving patients). The data for these 30 patients were compared with those for 30 patients from outside the Netherlands whose cases of meningitis due to S. suis type 2 were described between 1968 and 1985. No differences were found. The estimated annual risk of developing S. suis meningitis among Dutch abattoir workers and pig breeders was approximately 3.0/100,000--a rate 1,500 times higher than that among persons not working in the pork industry.

Cryptococcal meningitis in patients with AIDS

The Cryptococcus has become a major cause of meningitis in patients infected with the human immunodeficiency virus (HIV), and the expression of cryptococcal infection in this population of patients is quite unique. Often the infection is devoid of inflammatory response and is associated with very high antigen and fungal titers. Response to amphotericin therapy is erratic, and relapse is common. We have asked Dr. William E. Dismukes, principal investigator of the NIAID Mycoses Study Group, to discuss the following clinical questions: When and how does cryptococcal infection in HIV-infected patients present? How does it differ in HIV-infected and non-HIV-infected individuals? How is the diagnosis established? What is the sensitivity of the CSF cryptococcal antigen test? Is the serum antigen test of any value? What is the best way to treat patients--the recommended drugs, dosages, and duration of therapy? Is maintenance therapy necessary, and finally, what drugs are available for it? [Please note that an AIDS training program is now available for members of the Infectious Diseases Society of America and that details of this program appear in the Notices section of this Journal issue (pages 859-60).]

Neonatal infection and long-term neurodevelopmental outcome in the preterm infant

PURPOSE OF REVIEW

The relationship between infection, the inflammatory response and adverse neurodevelopmental outcome in preterm infants is slowly being elucidated. The developing brain, particularly the periventricular white matter, is vulnerable to cytotoxic and hypoxic/ischemic injury, which places these infants at increased risk for abnormal cognitive and motor functioning. This review summarizes current data evaluating associations between infection and neurodevelopmental outcome in the preterm infant.

RECENT FINDINGS

Preterm infants are at risk for intrauterine and postnatal infections. Recent studies have linked infection/inflammation associated with chorioamnionitis, sepsis and necrotizing enterocolitis with adverse neurodevelopmental outcome and impaired growth in preterm infants. Investigators have also shown associations between infection and brain injury, including severe intraventricular hemorrhage and periventricular leukomalacia. Very-low-birth-weight preterm infants are at substantial risk for neonatal infection, with associated morbidity and mortality. It is postulated that exposure of the preterm brain to inflammatory mediators during infectious episodes contributes to brain injury and poor developmental outcome.

SUMMARY

Enhanced understanding of the interaction of infection, inflammation and brain injury will be critical to developing strategies to improve neurodevelopmental outcome in preterm infants.

Fluconazole compared with amphotericin B plus flucytosine for cryptococcal meningitis in AIDS. A randomized trial

OBJECTIVE

To compare the efficacy of fluconazole with amphotericin B plus flucytosine in the treatment of cryptococcal meningitis.

DESIGN

Patients were randomly assigned to oral fluconazole, 400 mg/d, for 10 weeks or to amphotericin B, 0.7 mg/kg body weight daily for 1 week, then three times weekly for 9 weeks combined with flucytosine, 150 mg/kg d, in four divided doses.

SETTING

Los Angeles County-University of Southern California Medical Center.

PATIENTS

Between 15 February and 7 December 1988, 42 patients had evidence of their first episode of cryptococcal meningitis, of whom 21 participated in the trial. All patients enrolled were men with the acquired immunodeficiency syndrome (AIDS) except one woman who was receiving prednisone therapy and was excluded from the final analysis.

RESULTS

Of 14 patients with AIDS assigned to fluconazole, 8 (57%; 95% CI, 29% to 82%) failed; none of the 6 patients with AIDS failed who were assigned to amphotericin B plus flucytosine therapy (0%; CI, 0% to 46%) (Fisher exact test, P = 0.04). The mean duration of positive cerebrospinal fluid cultures was 40.6 +/- 5.4 days in patients receiving fluconazole and 15.6 +/- 6.6 days in patients receiving amphotericin B plus flucytosine (Mann-Whitney test, P = 0.02). Overall, 4 patients assigned to fluconazole therapy died whereas no patient assigned to amphotericin B plus flucytosine therapy died (Fisher exact test, P = 0.27).

CONCLUSION

Amphotericin B used in combination with flucytosine has superior mycologic and clinical efficacy compared with fluconazole for the treatment of cryptococcal meningitis in patients with AIDS.

Prospective evaluation of hearing impairment as a sequela of acute bacterial meningitis

As part of a prospective study of acute bacterial meningitis in children, we studied for five years the hearing of 185 infants and children who had acute bacterial meningitis when they were more than one month of age. Nineteen (10.3 per cent) of the patients had persistent bilateral or unilateral sensorineural hearing loss. The incidence of hearing loss as determined by electric-response audiometry and conventional tests was 31 per cent with Streptococcus pneumoniae, 10.5 per cent with Neisseria meningitidis, and 6 per cent with Hemophilus influenzae infections. Transient conductive hearing impairment was found in 16 per cent of the sample, but in no case was there apparent improvement in a sensorineural deficit over time. The site of disease resulting in impaired hearing cannot be stated with certainty, but involvement of the inner ear or auditory nerve was suspected. The number of days of illness (symptoms) before hospitalization and institution of antibacterial treatment was not correlated with the development of sensorineural deafness.

Sparing of the familiarity component of recognition memory in a patient with hippocampal pathology

Subject KN has a persistent anterograde amnesia as a result of brain injury following meningitis in 1993. MRI scans reveal a bilateral decrease in the volume of his hippocampal region (dentate gyrus, CA1-4, subicular cortices) of approximately 45% in both the right and left hemispheres, although the volume of his perirhinal cortex appears normal. Aside from some changes to his occipital lobe and bilateral shrinkage of the amygdala, the rest of his brain appears normal on recent quantitative MRI scans. A striking feature of his memory loss is his ability to perform at normal levels on some tests of recognition, despite his consistent deficit on tests of recall. Two tests designed specifically to distinguish performance of two putative divisions of recognition memory (the Remember/Know procedure and the use of receiver operating characteristics to distinguish familiarity and recollection), provide evidence for a selective sparing of the familiarity component of recognition. The dissociation within recognition memory supports dual-process models of recognition, and also supports proposals that anatomically linked regions within the medial temporal lobe make qualitatively different contributions to recognition.

Seizures and other neurologic sequelae of bacterial meningitis in children

BACKGROUND

Although the mortality rate among children with bacterial meningitis has decreased dramatically in recent decades, some patients are left with neurologic sequelae. It has not been clearly established which features of the acute illness predict the chronic neurologic sequelae, including late seizures or epilepsy.

METHODS

We followed 185 infants and children prospectively during and after acute bacterial meningitis. The mean duration of follow-up was 8.9 years (range, 0.1 to 15.5). During the first six years standard neurologic examinations were performed; telephone interviews were conducted thereafter.

RESULTS

One month after meningitis, 69 children (37 percent) had neurologic abnormalities. Many of these signs resolved within a year, leaving only 26 children (14 percent) with persistent deficits: 18 (10 percent) had only sensorineural hearing loss, and 8 (4 percent) had multiple neurologic deficits. Thirteen children (7 percent) had one or more late seizures not associated with fever. The presence of persistent neurologic deficits indicative of cerebral injury was the only independent predictor of late afebrile seizures (P less than 0.001).

CONCLUSIONS

After bacterial meningitis only children with permanent neurologic deficits are at high risk for epilepsy. Those with normal examinations after the acute illness have an excellent change of escaping serious neurologic sequelae, including epilepsy.

A comparison of ceftriaxone and cefuroxime for the treatment of bacterial meningitis in children

To compare ceftriaxone with cefuroxime for the treatment of meningitis, we conducted a study in which 106 children with acute bacterial meningitis were randomly assigned to receive either ceftriaxone (100 mg per kilogram of body weight per day, administered intravenously once daily; n = 53) or cefuroxime (240 mg per kilogram per day, administered intravenously in four equal doses; n = 53). The mean age of the children was 3 years (range, 42 days to 16 years), and the characteristics of the two treatment groups were comparable at admission. Excluded from the study were eight other children who died within 48 hours of admission. After 18 to 36 hours of therapy, cultures of cerebrospinal fluid remained positive for 1 of the 52 children (2 percent) receiving ceftriaxone for whom cultures were available and 6 of 52 (12 percent) receiving cefuroxime (P = 0.11). In both groups the mean duration of antibiotic therapy was 10 days. The clinical responses to therapy were similar in the two treatment groups, and all 106 children were cured. Reversible biliary pseudolithiasis was detected by serial abdominal ultrasonography only in the children treated with ceftriaxone (16 of 35 vs. 0 of 35; P less than 0.001). The treatment of three children was switched from ceftriaxone to alternative antibiotics because these children had upper abdominal pain. Other side effects were infrequent in both groups. At follow-up examination two months later, moderate-to-profound hearing loss was present in two children (4 percent) treated with ceftriaxone and in nine (17 percent) treated with cefuroxime (P = 0.05); other neurologic abnormalities were similar in the two treatment groups. We conclude that ceftriaxone is superior to cefuroxime for the treatment of acute bacterial meningitis in children and that the benefits of milder hearing impairment and more rapid sterilization of the cerebrospinal fluid with ceftriaxone outweigh the problem of reversible biliary pseudolithiasis with this drug.

Impact of HIV infection on meningitis in Harare, Zimbabwe: a prospective study of 406 predominantly adult patients

OBJECTIVE

To determine the causative organisms and characteristics of patients presenting with features of meningitis.

DESIGN

A prospective cross-sectional study.

SETTING

Two tertiary university-affiliated hospitals in Harare, Zimbabwe.

PATIENTS

Four-hundred and six patients clinically suspected to have meningitis.

MAIN OUTCOME MEASURES

Causative organisms of meningitis; clinical and cerebrospinal fluid characteristics.

RESULTS

Four-hundred and six predominantly adult (95% were aged > or = 18 years) patients were suspected to have meningitis. Of the 200 patients confirmed to have meningitis, 89 (45%) had cryptococcal meningitis (CM), 54 (27%) had mononuclear meningitis (MM), 31 (16%) had pyogenic meningitis (PM), 24 (12%) had tuberculous meningitis (TBM) and 2 (1%) had undefined meningitis. HIV seropositivity was 100% in CM, 83% in MM, 81% in PM and 88% in TBM patients. In-hospital mortality rate was 38.8% for CM, 34.9% for MM, 68% for PM and 66.7% for TBM. HIV seropositivity was 80% in the 206 patients not found to have meningitis.

CONCLUSIONS

All patients suspected to have meningitis had a high HIV sero positivity irrespective of whether they were later confirmed to have meningitis or not. CM was the most common type of meningitis seen. In-hospital mortality was high irrespective of the cause of meningitis.

Toxicity of amphotericin B plus flucytosine in 194 patients with cryptococcal meningitis

A multicenter prospective randomized trial of four versus six weeks of amphotericin B, 0.3 mg/kg per day, plus flucytosine, 150 mg/kg per day, was performed with 194 patients with cryptococcal meningitis. One or more toxic drug reactions developed in 103 patients: azotemia (51), renal tubular acidosis (two), leukopenia (30), thrombocytopenia (22), diarrhea (26), nausea/vomiting (10), and hepatitis (13). The four- and six-week regimens were complicated by toxicity in 44 percent and 43 percent of cases, respectively. Toxicity appeared during the first two weeks of therapy in 56 percent and during the first four weeks in 87 percent. Azotemia did not occur more frequently in renal transplant recipients or diabetic patients. Cytopenias did not appear more often in patients with hematologic malignancies or those receiving immunosuppressive therapies. Toxic reactions that contributed to death developed in five patients (two with azotemia, one with pancytopenia, one with hepatitis, one with ileus). Amphotericin B-induced azotemia was not a significant risk factor for the subsequent development of bone marrow, gastrointestinal, or hepatic toxicity attributable to flucytosine. Flucytosine toxicity was associated with peak serum flucytosine levels of 100 micrograms/ml or more during two or more weeks of therapy (p = 0.005). Peak 5-fluorouracil levels were not predictive of toxicity. An initial dose of flucytosine is recommended based on the creatinine clearance: 150 mg/kg per day at a creatinine clearance above 50 ml/minute, 75 mg/kg per day at a creatinine clearance of 26 to 50 ml/minute, and 37 mg/kg per day at a creatinine clearance of 13 to 25 ml/minute. The serum creatinine level should be monitored twice weekly and the creatinine clearance weekly during therapy in order to anticipate changes in serum flucytosine concentration. In addition, it is recommended that the serum flucytosine level be determined two hours after an oral dose once a week, and that the dose be adjusted to maintain a level of 50 to 100 micrograms/ml.

Central nervous system disease in systemic lupus erythematosus. Therapy and prognosis

The effect of corticosteroid therapy in 28 patients with 52 episodes of neuropyciatric disease in systemic lupus erythematosus (SLE) was elevated. Categories of organic central nervous system disease were seizures (eight patients), organic brain syndromes (nine patients), aseptic meningitis (four patients) and a variety of focal neurologic findings (seven patinets). Fourteen pateints had 15 episodes of functional psychosis without other evidence of neurologic disease. Although there was a general correlation between clinical and serologic evidnce of active SLE and the development of organic neurolgic disease, there was no evidence that therapy with very large doses of corticosteroids was beneficial. Of the deaths in this series, two were due to probable active SLE involving the central nervous system wheras five were attributable to complications of therapy. The long-term morbidity, likewise, was high in the patients who recieved large doses of corticosteroids. In all, 12 patients had major complications of corticosteroid therapy. Functional psychosis was usually preciptated by corticsoteroid therapy and respond to a reduction in steroid dosage and administration of psychotropic drugs.

IgG4-related disease and hypertrophic pachymeningitis

Hypertrophic pachymeningitis (HP) is an inflammatory condition in which the dura mater of the cranium or spine becomes thickened, leading to symptoms that result from mass effect, nerve compression, or vascular compromise. The differential diagnosis of HP includes immune-mediated conditions such as rheumatoid arthritis and vasculitis, malignancies, and infections. Many times, no diagnosis is reached; in such cases, the disease has been described as idiopathic HP. IgG4-related disease (IgG4-RD) is a recently described inflammatory condition known to cause tumefactive lesions at myriad anatomical locations. Both IgG4-RD and idiopathic HP share similar demographics, histopathology, and natural history. We hypothesized that IgG4-RD is a common cause of idiopathic HP.To investigate this hypothesis, we identified all pathology specimens diagnosed as noninfectious HP during 25 years at our institution. Fourteen cases had stained slides and paraffin blocks to permit review of the original hematoxylin and eosin stained slides as well as immunostaining of cell blocks. Recently published consensus guidelines describing characteristic histopathology and the necessary quantity of IgG4+ plasma cell infiltrate were used to diagnose IgG4-RD.Four cases (66.6%) that had been regarded previously as representing idiopathic HP were diagnosed as IgG4-RD; of all the reviewed cases, IgG4-RD represented 29% of cases. Of the remaining cases, 3 cases were associated with granulomatosis with polyangiitis (GPA), 2 with lymphoma, and 1 each with rheumatoid arthritis, giant cell arteritis, and sarcoidosis. Two of the cases could not be diagnosed more precisely and were classified as undifferentiated HP. Clinical history, serologic tests, cerebrospinal fluid studies, and radiology alone could not identify the cause of HP. Rather, biopsy with histopathology and immunostaining was necessary to reach an accurate diagnosis. Significant IgG4+ plasma cell infiltrates were observed in rheumatoid arthritis, granulomatosis with polyangiitis, and lymphoma, underscoring the importance of histopathology in making the diagnosis of IgG4-RD.This case series demonstrates that IgG4-RD may be the most common etiology of noninfectious HP and highlights the necessity of biopsy for accurate diagnosis.

Transcranial contralateral cochlear stimulation in unilateral deafness

OBJECTIVES

The purpose of this study is to evaluate the effectiveness of Bone Anchored Cochlear Stimulator (BAHA) in transcranial routing of signal by implanting the deaf ear. Study design and settings Eighteen patients with unilateral deafness were included in a multisite study. They had a 1-month pre-implantation trial with a contralateral routing of signal (CROS) hearing aid. Their performance with BAHA was compared with the CROS device using speech reception thresholds, speech recognition performance in noise, and the Abbreviated Profile Hearing Benefit and Single Sided Deafness questionnaires.

RESULTS

Patients reported a significant improvement in speech intelligibility in noise and greater benefit from BAHA compared with CROS hearing aids. Patients were satisfied with the device and its impact on their quality of life. No major complications were reported. Conclusion and significance BAHA is effective in unilateral deafness. Auditory stimuli from the deaf side can be transmitted to the good ear, avoiding the limitations inherent in CROS amplification.

Brain abscess: a review of recent experience

From 1961 through 1973, 60 patients with brain abscess were treated at the Mayo Clinic by surgical excision and antimicrobial therapy. The operative mortality was 17%, which was identical to a similar series reported in 1959. The patients who had the diagnosis of brain abscess confirmed at autopsy and who never underwent operation (24 patients) were more elderly than the group operated on, and a higher percentage had multiple brain abscess. Severe systemic disease or multisystem disease, or both, usually precluded a vigorous surgical approach among the nonsurgical group. Etiologic, diagnostic, and microbiologic factors were examined to develop an approach to antimicrobial therapy.

COVID-19 and the nervous system

A pandemic due to novel coronavirus arose in mid-December 2019 in Wuhan, China, and in 3 months' time swept the world. The disease has been referred to as COVID-19, and the causative agent has been labelled SARS-CoV-2 due to its genetic similarities to the virus (SARS-CoV-1) responsible for the severe acute respiratory syndrome (SARS) epidemic nearly 20 years earlier. The spike proteins of both viruses dictate tissue tropism using the angiotensin-converting enzyme type 2 (ACE-2) receptor to bind to cells. The ACE-2 receptor can be found in nervous system tissue and endothelial cells among the tissues of many other organs.Neurological complications have been observed with COVID-19. Myalgia and headache are relatively common, but serious neurological disease appears to be rare. No part of the neuraxis is spared. The neurological disorders occurring with COVID-19 may have many pathophysiological underpinnings. Some appear to be the consequence of direct viral invasion of the nervous system tissue, others arise as a postviral autoimmune process, and still others are the result of metabolic and systemic complications due to the associated critical illness. This review addresses the preliminary observations regarding the neurological disorders reported with COVID-19 to date and describes some of the disorders that are anticipated from prior experience with similar coronaviruses.

Use of multichannel cochlear implants in obstructed and obliterated cochleas

Obstruction that occurs within the scala tympani (after meningitis or otosclerosis) has been considered a contraindication for placement of a multichannel cochlear implant electrode. Two patients who exhibited radiographic evidence of intracochlear narrowing and obliteration were implanted with multichannel electrodes. Implantation involved creation of a channel for the electrode to wrap around the modiolus. The middle ear cavity and the external auditory canal also had to be removed to gain access. The response of one of the patients was similar to that of patients with normal cochlear anatomy who use multichannel devices. These early experiences, along with one case in which a single-channel electrode was placed, is presented.