Intracerebral hematoma extends via perivascular spaces and perineurium.

Intracerebral hemorrhage (ICH) is a devastating disorder associated with high morbidity and mortality. ICH results in the formation of hematoma that affects not only the primary site of injury but also the remote regions. In fact, hematoma can extend via perivascular spaces (also called Virchow-Robin spaces, VRS) and perineurium in an animal model of ICH. In the present study, we used magnetic resonance imaging (MRI) with susceptibility-weighted imaging (SWI) to investigate the characteristics of the perivascular and perineural extensions of hematomas in patients with ICH. A total of 20 ICH patients without secondary subarachnoid and secondary intraventricular hemorrhages were recruited. Brain MRI scans, including SWI, T1, and T2-weighted images, were performed between 17 h to 7 days after the onset of ICH. MRI with SWI revealed that paramagnetic substances spread along the VRS or the perineurium. Such distribution could cause the formation of cerebral microbleeds (CMBs). However, the distribution of remote hemorrhagic lesions varied, depending on the size and location of the original hematoma. The unenhanced CT scans of the 20 patients did not show any hyperdensity around the blood vessels and nerve tracts outside the hematoma. These results indicate the perivascular and perineural extensions of hematomas in patients with ICH, which is formed by the leakage of the original hematoma via the VRS or perineurium. We also provide a new explanation for the series of pathological processes involved in ICH, including the remote effects of hematoma and the formation of CMBs in patients with ICH.

Comparative pharmacokinetics of continuous and conventional intrathecal amphotericin B in rabbits.

We previously reported a new effective therapy, continuous intrathecal amphotericin B (AMB), for the treatment of cryptococcal meningitis, which had fewer side effects and complications than conventional intrathecal AMB. In this study, the pharmacokinetics of continuous intrathecal administration and conventional intrathecal AMB were compared in rabbits, providing a pharmacokinetic basis for the use of continuous intrathecal AMB therapy. The AMB concentration in the cerebrospinal fluid (CSF), sampled via an inserted cisterna magna catheter, was determined by a liquid chromatography-tandem mass spectrometry assay. The results revealed significant pharmacokinetic differences between the two groups. In the continuous intrathecal group (0.15 mg/kg/24 h), the concentration of AMB peaked 7.01 µg/ml at 4 h and then decreased to a stable level of 1.0 to 1.34 µg/ml, with no neurological impairments, while in the conventional intrathecal group (0.015 mg/kg), the drug concentration reached a peak of 3.41 µg/ml at 1 h and then decreased progressively, with fever and neurological impairments, including convulsion and paralysis. The pharmacokinetic results indicated that the continuous intrathecal AMB is a more effective and safe therapy than the conventional intrathecal AMB, with comparatively rational pharmacokinetics and fewer neurological impairments.

[Expression of glucose transporter 1 in the blood-brain barrier around hematoma in rats with cerebral hemorrhage].

OBJECTIVE: To observe the expression of glucose transporter 1 (GLUT1) in the blood-brain barrier around the hematoma in rats with cerebral hemorrhage. METHOD: Brain tissue around the hematoma in rats with cerebral hemorrhage was prepared for GLUT1 detection by immunohistochemistry. RESULT: The expression of GLUT1 upregulated within 48 h after cerebral hemorrhage and downregulated afterwards. CONCLUSION: Protective reaction of the blood-brain barrier can be initiated to ensure glucose supply to the neurons against the injury by cerebral hemorrhage.

[Continuous intraspinal ceftazidime administration in a case for treatment of purulent meningitis].

OBJECTIVE: To investigate the feasibility of continuous intraspinal ceftazidime administration for treatment of purulent meningitis due to Achromobacter infection. METHODS: A patient with established diagnosis of purulent meningitis due to Achromobacter infection was admitted, who failed to respond favorably to a 3-day ceftazidime treatment administered intravenously. Continuous intraspinal ceftazidime administration at the dose of 0.2 g/d was then attempted through a catheter placed in the cisterna magna in addition to intravenous ceftazidime for 3 days, which resulted in obvious relief of the symptoms. The catheter was subsequently withdrawn, and the patient received further treatment with additional intravenous ceftazidime for a week. RESULTS: The symptoms of purulent meningitis was significantly improved after a 3-day continuous intraspinal ceftazidime administration, and the patient was eventually cured after completion of the treatment course. Intrathecal ceftazidime was also attempted previously but failed due to intolerance of pains in the legs. No relapse was observed in this case 3 months after the discharge. CONCLUSION: Continuous intraspinal ceftazidime administration can be effective and safe for treatment of purulent meningitis.