Effects of the implantation of Ommaya reservoir in children with tuberculous meningitis hydrocephalus: a preliminary study

Delivery of Neuroregenerative Proteins to the Brain for Treatments of Neurodegenerative Brain Diseases

Neurodegenerative brain diseases such as Alzheimer's disease (AD), multiple sclerosis (MS), and Parkinson's disease (PD) are difficult to treat. Unfortunately, many therapeutic agents for neurodegenerative disease only halt the progression of these diseases and do not reverse neuronal damage. There is a demand for finding solutions to reverse neuronal damage in the central nervous system (CNS) of patients with neurodegenerative brain diseases. Therefore, the purpose of this review is to discuss the potential for therapeutic agents like specific neurotrophic and growth factors in promoting CNS neuroregeneration in brain diseases. We discuss how BDNF, NGF, IGF-1, and LIF could potentially be used for the treatment of brain diseases. The molecule's different mechanisms of action in stimulating neuroregeneration and methods to analyze their efficacy are described. Methods that can be utilized to deliver these proteins to the brain are also discussed.

Comprehensive Therapeutic Approaches to Tuberculous Meningitis: Pharmacokinetics, Combined Dosing, and Advanced Intrathecal Therapies

Tuberculous meningitis (TBM) presents a critical neurologic emergency characterized by high mortality and morbidity rates, necessitating immediate therapeutic intervention, often ahead of definitive microbiological and molecular diagnoses. The primary hurdle in effective TBM treatment is the blood-brain barrier (BBB), which significantly restricts the delivery of anti-tuberculous medications to the central nervous system (CNS), leading to subtherapeutic drug levels and poor treatment outcomes. The standard regimen for initial TBM treatment frequently falls short, followed by adverse side effects, vasculitis, and hydrocephalus, driving the condition toward a refractory state. To overcome this obstacle, intrathecal (IT) sustained release of anti-TB medication emerges as a promising approach. This method enables a steady, uninterrupted, and prolonged release of medication directly into the cerebrospinal fluid (CSF), thus preventing systemic side effects by limiting drug exposure to the rest of the body. Our review diligently investigates the existing literature and treatment methodologies, aiming to highlight their shortcomings. As part of our enhanced strategy for sustained IT anti-TB delivery, we particularly seek to explore the utilization of nanoparticle-infused hydrogels containing isoniazid (INH) and rifampicin (RIF), alongside osmotic pump usage, as innovative treatments for TBM. This comprehensive review delineates an optimized framework for the management of TBM, including an integrated approach that combines pharmacokinetic insights, concomitant drug administration strategies, and the latest advancements in IT and intraventricular (IVT) therapy for CNS infections. By proposing a multifaceted treatment strategy, this analysis aims to enhance the clinical outcomes for TBM patients, highlighting the critical role of targeted drug delivery in overcoming the formidable challenges presented by the blood-brain barrier and the complex pathophysiology of TBM.

Cerebrospinal fluid findings of infant tuberculous meningitis: a scoping review

BACKGROUND

Cerebrospinal fluid (CSF) examinations play an important role in the diagnosis of tuberculous meningitis (TBM). However, their yield in the diagnosis of infant TBM remains unclear. This scoping review aims to detail the role of CSF examination for the diagnosis of infant TBM.

METHODS

A comprehensive literature search of PubMed, EBSCO, Embase, Scopus, Web of Science, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials was performed to identify articles published prior to October 14th, 2021. Articles describing the results of CSF exanimations among infant TBM were eligible for inclusion. Data extracted from each study included age, sex, CSF microbiological evidence (such as AFB smear, TB PCR, and TB culture), and routine CSF examinations (such as appearance, red blood cell count, white blood cell count, protein, and glucose).

RESULTS

A total of 98 cases were included in the final analysis. The yield of microbiological methods was listed as follows: CSF AFB smear, 20.5% (9/44); CSF TB culture 47.5% (29/61); CSF TB PCR, 65.0% (26/40); the combination of them, 57.3% (47/82). According to Marais criteria, the positivities of CSF examinations were calculated as follows: WBC count (ref, 50-500/μL), 65.5% (55/84); lymphocyte predominance (ref, >0.5), 75.4% (49/65); total protein (ref, >100 mg/dL), 67.8% (59/87); glucose (ref, <2.2 mmol/L, or CSF/serum ratio < 0.5), 68.2% (58/85).

CONCLUSIONS

Our data demonstrated that routine microbiological tools for infant TBM diagnosis have a sensitivity ranging from 20.5% to 65.0%, and most CSF features are non-specific and insufficient to predict a diagnosis of infant TBM. Therefore, further effort is required to develop new tools for infant TBM diagnosis.Key messages: Routine microbiological tools (such as acid-fast bacilli smear, PCR, and culture) have an unsatisfactory sensitivity for infant TBM diagnosis, and most CSF features are non-specific and insufficient to predict a diagnosis of infant TBM. Therefore, further effort is required to develop new tools for infant TBM diagnosis.

Overcoming the blood-brain barrier for the therapy of malignant brain tumor: current status and prospects of drug delivery approaches

Besides the broad development of nanotechnological approaches for cancer diagnosis and therapy, currently, there is no significant progress in the treatment of different types of brain tumors. Therapeutic molecules crossing the blood-brain barrier (BBB) and reaching an appropriate targeting ability remain the key challenges. Many invasive and non-invasive methods, and various types of nanocarriers and their hybrids have been widely explored for brain tumor treatment. However, unfortunately, no crucial clinical translations were observed to date. In particular, chemotherapy and surgery remain the main methods for the therapy of brain tumors. Exploring the mechanisms of the BBB penetration in detail and investigating advanced drug delivery platforms are the key factors that could bring us closer to understanding the development of effective therapy against brain tumors. In this review, we discuss the most relevant aspects of the BBB penetration mechanisms, observing both invasive and non-invasive methods of drug delivery. We also review the recent progress in the development of functional drug delivery platforms, from viruses to cell-based vehicles, for brain tumor therapy. The destructive potential of chemotherapeutic drugs delivered to the brain tumor is also considered. This review then summarizes the existing challenges and future prospects in the use of drug delivery platforms for the treatment of brain tumors.

Intrathecal therapy for tuberculous meningitis: propensity-matched cohort study

OBJECTIVE

The study aimed to determine the safety and efficacy of intrathecally administered isoniazid (INH) and prednisolone in addition to systemic anti-TB therapy and compare it with systemic anti-TB therapy alone in adult patients with tuberculous meningitis (TBM).

METHODS

In this retrospective study, patients were categorized into two groups: Group A patients received systematic anti-TB therapy alone, Group B patients received IT INH (50 mg) and prednisolone (25 mg) twice a week together with the same standard systemic anti-TB therapy as Group A, in addition to the standard systemic anti-TB therapy. Functional outcomes were compared between the two groups in a prosperity-matched cohort using propensity score matching (PSM) method.

RESULTS

A total of 198 patients with TBM were enrolled. After PSM, 30 patients from each group were analyzed, so that there was no significant difference in the characteristics of the two groups. Mortality at follow-up was significantly lower among patients receiving additional IT therapy (4/30, 13.3%) compared with matched patients receiving systemic anti-TB therapy alone (11/30, 36.7%, P value = 0.037).

CONCLUSIONS

In this propensity score-matched cohort, the addition of IT INH and prednisolone to systemic anti-TB therapy could be effective for the better outcome among adult TBM patients. Further large-scale, prospective, and randomized controlled trials are warranted to the best timing and indication of IT therapy.

Clinical Profile, Yield of Cartridge-based Nucleic Acid Amplification Test (GeneXpert), and Outcome in Children with Tubercular Meningitis

Background:

GeneXpert MTB/RIF is a test for early, rapid diagnosis of tubercular meningitis (TBM).

Aim:

The aim of this article was to study the clinical profile, radiological features, yield of GeneXpert, neurosurgical interventions, and outcome of TBM in children.

Settings and Design:

This was a retrospective and prospective observational study.

Materials and Methods:

Diagnosis was based on the uniform research definition criteria and was staged according to the British Medical Research Council. Mantoux test, analysis of cerebrospinal fluid (CSF), CSF GeneXpert, and radiological investigations were performed.

Results:

Of 36 patients, 50% were aged 1–5 years. Fever (100%), headache (82%), altered sensorium (80%), and vomiting (66%) were common features. Twelve (33%) had contact with active case of tuberculosis; 32 received Bacille Calmette Guarin vaccination. Neurological features included severe deterioration in sensorium (Glasgow Coma Scale < 8) (38%), mild and moderate deficit in sensorium (31%), hemiparesis (41%), and involvement of sixth (25%) and seventh (22%) cranial nerves. Cerebral vision impairment (25%), papilledema (25%), and dystonia (22%) were other findings. CSF GeneXpert was positive in 37% (12/33) patients. Hydrocephalus and basal exudates (75%) were noted on neuro-imaging. Surgical intervention was performed in children with hydrocephalus (13/27). Omayya reservoir was placed in seven children, of which five needed conversion to ventriculoperitoneal (VP) shunt; direct VP shunt was carried out in six (6/13). Good outcome was noted in 78% at discharge. Stage III TBM (P = 0.0001), cerebral infarcts (P = 0.0006), and motor deficits (P = 0.03) were associated with poor outcome. Sequelae included learning difficulties with poor scholastic performance (31.5%).

Conclusion:

GeneXpert has high diagnostic specificity, but negative results do not rule out TBM. CSF GeneXpert provided quick results. Placement of Ommaya reservoir in TBM stage II and III with hydrocephalus was not successful. Hydrocephalus was managed conservatively with success (53%).

Complications of intracerebroventricular chemotherapy via subgaleal reservoir in primary central nervous system lymphoma: A single-institution experience on 1247 installations in 94 consecutive patients

The implantation of a subgaleal reservoir intracerebroventricular (ICV port) in order to apply ICV chemotherapy in patients with leptomeningeal cancer may be complicated by misplacement of the device, pericatheter leucencephalopathy, hemorrhage and iatrogenic ventriculitis/meningitis. Here we analyzed the occurrence of such complications in patients with primary central nervous system lymphoma (PCNSL) treated with systemic and ICV methotrexate- and cytarabine-based chemotherapy. We retrospectively reviewed the medical records of 94 consecutive patients (1247 installations), who had received an ICV port for intraventricular chemotherapy for treatment of histologically confirmed PCNSL at our institution between September 2005 and October 2018. Infectious and noninfectious complications were systematically recorded including clinical, laboratory, and imaging data. In 9/94 patients (9.6%), a misplacement of the ICV port seen on the postoperative computed tomography scan was corrected immediately and chemotherapy was then continued as planned. In 5/94 patients (5.3%), symptomatic noninfectious complications were observed (four patients with symptomatic pericatheter leucencephalopathy and one patient with surgical scar dehiscence with CSF leak). In 8/94 patients (8.5%), asymptomatic white matter lesions around the catheter were visible on cerebral magnetic resonance imaging after completion of therapy. The rate of infectious complications was 6/94 patients (6.4%). No complication was lethal or required intensive care monitoring. This retrospective study shows that complications of ICV treatment have to be expected in a fraction of patients, however, in this series these complications were manageable and did not result in long-term deficits.

Intraventricular administration of antibiotics by ommaya reservoir for patients with multidrug-resistant Acinetobacter baumannii central nervous system infection

AIM

To investigate whether the Ommaya reservoir can be used to treat multiple drug-resistant Acinetobacter baumannii (MDR-AB) infections in the central nervous system (CNS).

METHODS

Retrospectively analyzed the clinical records and data of 15 MDR-AB CNS infection patients who were treated in our neuro-ICU. Four patients with MDR-AB CNS infection were involved in this study.

RESULTS

We report the successful treatment of MDR-AB CNS infection by Ommaya reservoirs and intraventricular antibiotic (IVA) administration. Ommaya reservoirs allow serial CSF sampling and IVA injection. Furthermore, debridement can be performed during the operation to insert the Ommaya.

CONCLUSION

Ommaya reservoirs can be used as an effective treatment approach of MDR-AB or other multidrug-resistant Gram-negative bacteria CNS infections.

Overcoming the Blood–Brain Barrier. Challenges and Tricks for CNS Drug Delivery

Treatment of certain central nervous system disorders, including different types of cerebral malignancies, is limited by traditional oral or systemic administrations of therapeutic drugs due to possible serious side effects and/or lack of the brain penetration and, therefore, the efficacy of the drugs is diminished. During the last decade, several new technologies were developed to overcome barrier properties of cerebral capillaries. This review gives a short overview of the structural elements and anatomical features of the blood–brain barrier. The various in vitro (static and dynamic), in vivo (microdialysis), and in situ (brain perfusion) blood–brain barrier models are also presented. The drug formulations and administration options to deliver molecules effectively to the central nervous system (CNS) are presented. Nanocarriers, nanoparticles (lipid, polymeric, magnetic, gold, and carbon based nanoparticles, dendrimers, etc.), viral and peptid vectors and shuttles, sonoporation and microbubbles are briefly shown. The modulation of receptors and efflux transporters in the cell membrane can also be an effective approach to enhance brain exposure to therapeutic compounds. Intranasal administration is a noninvasive delivery route to bypass the blood–brain barrier, while direct brain administration is an invasive mode to target the brain region with therapeutic drug concentrations locally. Nowadays, both technological and mechanistic tools are available to assist in overcoming the blood–brain barrier. With these techniques more effective and even safer drugs can be developed for the treatment of devastating brain disorders.

Intracerebroventricular Delivery as a Safe, Long-Term Route of Drug Administration

Intrathecal delivery methods have been used for many decades to treat a broad range of central nervous system disorders. A literature review demonstrated that intracerebroventricular route is an established and well-tolerated method for prolonged central nervous system drug delivery in pediatric and adult populations. Intracerebroventricular devices were present in patients from one to 7156 days. The number of punctures per device ranged from 2 to 280. Noninfectious complication rates per patient (range, 1.0% to 33.0%) were similar to infectious complication rates (0.0% to 27.0%). Clinician experience and training and the use of strict aseptic techniques have been shown to reduce the frequency of complications.

Ommaya reservoir infection rate: a 6-year retrospective cohort study of Ommaya reservoir in pediatrics

OBJECTIVES

In this study, we investigated Ommaya reservoir among pediatric patients, its infection rate, and the predisposing factors. We also investigated its role in the reduction of CSF protein. Finally, we explored other factors that would influence the decision to insert an Ommaya in comparison to external ventricular drainage.

METHODS

This is a 6-year retrospective cohort study from a tertiary hospital in Saudi Arabia.

RESULTS

In our study, females were 48.9% (n = 22) while males were 51.1% (n = 23). The mean age at insertion was 2.9 days, SD of 1.67 day. The mean weight at insertion was 0.98 kg, SD of 0.57 kg. The total duration of Ommaya days was 2523 days. The median duration of the reservoir was 21 days. The Ommaya reservoir infection rate was 6.6%. We found an association between organisms cultured from urinary tract and the organisms cultured from the CSF. We also found that CSF protein level is lower in non-infected reservoirs in comparison to those with infection. The number of Ommaya days and the number of days of infection could not explain the mean CSF protein.

CONCLUSIONS

Ommaya reservoir has a low infection rate. Although CSF protein increased by infection, we failed to prove that Ommaya tapping provides a reduction in the CSF protein and, hence, reduction of shunt malfunctions thereafter. We conclude with expert opinions that take into account the psychological factors in addition to the clinical sense in choosing between Ommaya reservoir and external ventricular drainage (EVD).

Cerebroventricular clozapine would be a viable treatment modality for clozapine-dependent schizophrenia patients with neutropenia

The atypical antipsychotic clozapine is very effective for treatment of schizophrenia, but it causes agranulocytosis requiring drug cessation in up to 2% of cases. There has been some success rechallenging with clozapine at a later date or giving granulocyte colony stimulating factor or lithium while continuing clozapine. However, there are still some patients for whom these strategies do not work yet who cannot be controlled on other medications. This paper proposes that for such individuals, cerebroventricular administration of clozapine via Ommaya catheters could allow continued use of clozapine therapy. Direct infusion into cerebrospinal fluid means far smaller amounts of drug would be needed for efficacy, and clozapine concentrates in the central nervous system where it would not be exposed to bone marrow stem cells to cause agranulocytosis. This treatment paradigm would also provide a means for court-ordered clozapine therapy and a possible delivery system for future therapeutics based on trophic factors such as brain-derived neurotrophic factor.