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Advanced Drug Delivery Reviews 2020Administration of substances directly into the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord is one approach that can circumvent the blood-brain...
Administration of substances directly into the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord is one approach that can circumvent the blood-brain barrier to enable drug delivery to the central nervous system (CNS). However, molecules that have been administered by intrathecal injection, which includes intraventricular, intracisternal, or lumbar locations, encounter new barriers within the subarachnoid space. These barriers include relatively high rates of turnover as CSF clears and potentially inadequate delivery to tissue or cellular targets. Nanomedicine could offer a solution. In contrast to the fate of freely administered drugs, nanomedicine systems can navigate the subarachnoid space to sustain delivery of therapeutic molecules, genes, and imaging agents within the CNS. Some evidence suggests that certain nanomedicine agents can reach the parenchyma following intrathecal administration. Here, we will address the preclinical and clinical use of intrathecal nanomedicine, including nanoparticles, microparticles, dendrimers, micelles, liposomes, polyplexes, and other colloidalal materials that function to alter the distribution of molecules in tissue. Our review forms a foundational understanding of drug delivery to the CSF that can be built upon to better engineer nanomedicine for intrathecal treatment of disease.
Topics: Animals; Biological Transport; Blood-Brain Barrier; Cerebral Ventricles; Cerebrospinal Fluid; Drug Delivery Systems; Humans; Injections, Spinal; Liposomes; Micelles; Nanoparticles; Subarachnoid Space
PubMed: 32142739
DOI: 10.1016/j.addr.2020.02.006 -
Neurosurgical Review Feb 2021Foramen magnum decompression (FMD) is widely accepted as the standard treatment for syringomyelia associated with Chiari type I malformation (CMI). Despite extensive... (Meta-Analysis)
Meta-Analysis
Foramen magnum decompression (FMD) is widely accepted as the standard treatment for syringomyelia associated with Chiari type I malformation (CMI). Despite extensive clinical investigations, relevant surgical details are still matter of debate. The authors performed a systematic review and meta-analysis of the literature examining the radiological outcome of syringomyelia in adult patients with CMI after different surgical strategies. PRISMA guidelines were followed. A systematic search of three databases was performed for studies published between 1990 and 2018. Our systematic review included 13 studies with a total of 276 patients with CMI associated with syringomyelia. Overall, the rate of post-operative radiological improvement at last follow-up was 81.1% (95% CI 73.3-88.9%; p < 0.001; I = 71.4%). The rate of post-operative syrinx shrinkage did not differ significantly among both groups of decompression with the extra-arachnoidal technique and arachnoid dissection (90%, 95% CI 85.1-94.8%, I = 0% vs 79.8%, 95% CI 61.7-98%, I = 85.5%). A lower rate of post-operative radiological syrinx shrinkage was observed after decompression with splitting of the outer layer of the dura (55.6% 95% CI 40.5-70.8%, I = 0%). CSF-related complications and infections were similar among the different groups. Our meta-analysis found that FMD with the extra-arachnoidal technique and arachnoid dissection provides similar results in terms of post-operative shrinkage of syringomyelia. Patients undergoing decompression with splitting of the dura presented the lower rate of syrinx reduction. These data should be considered when choosing the surgical approach in adult patients with CMI associated with syringomyelia.
Topics: Arnold-Chiari Malformation; Decompression, Surgical; Foramen Magnum; Humans; Neurosurgical Procedures; Syringomyelia; Treatment Outcome
PubMed: 31953784
DOI: 10.1007/s10143-020-01239-w -
Child's Nervous System : ChNS :... Apr 2020Primary cysts are believed to arise from the splitting of the arachnoid membrane during prenatal development and can be diagnosed in utero. Prenatal diagnosis is...
INTRODUCTION
Primary cysts are believed to arise from the splitting of the arachnoid membrane during prenatal development and can be diagnosed in utero. Prenatal diagnosis is uncommon; therefore, the evidence base for counselling expectant mothers is limited. The purpose of this article is to present a case series and review the current literature on prenatally diagnosed arachnoid cysts.
METHOD
A keyword search of hospital electronic records was performed for all patients with a prenatally diagnosed arachnoid cyst at a tertiary neurosurgical centre. Case notes were reviewed for all patients diagnosed between 2005 and 2017. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to structure a systematic review of all English language articles published up to May 2018.
RESULTS
A total of eight eligible patients were identified from our own records and 123 from the literature. Sixty-eight per cent of patients had a normal outcome. Sixty-three per cent of patients underwent surgical intervention which was not associated with abnormal outcome. The diagnosis of syndromic/genetic diagnosis (p < 0.001) and the presence of other intra-cranial anatomical abnormalities (p = 0.05) were significant predictors of abnormal outcome.
CONCLUSION
The pathogenesis and prognosis of a prenatal arachnoid cyst diagnosis remain unclear. These results suggest favourable outcomes from simple cysts without associated abnormalities and expectant mothers should be counselled accordingly. A wider prospective review is required to better established evidence-based practice.
Topics: Arachnoid Cysts; Female; Humans; Pregnancy; Prenatal Diagnosis; Prognosis; Prospective Studies
PubMed: 31897633
DOI: 10.1007/s00381-019-04477-6