Although VPS placement is one of the most important and effective treatments to increase the survival rate of patients with HCM, and to decrease elevated ICP, its effects on the long-term outcomes of these patients remain unclear. This was the focus of our study. We found the following results: 1) patients with VPS showed obvious CSF changes, such as decreased CSF glucose levels and increased CSF protein levels; 2) VPS placement effectively decreased HICP and mortality in patients with intracranial hypertension; and 3) the change in the CSF profile after VPS placement led to a higher rate of misdiagnosis of tuberculous meningitis in these patients.
In this study, VPS placement significantly reduced HICP and 24-week mortality; however, there was a higher rate of misdiagnosis of tuberculous meningitis and steroid use in patients in the VPS group. Some studies have indicated that VPS placement could significantly decrease ICP and cryptococcal counts in patients without HIV infection [11–13]. However, there is a paucity of data on the effects of a VPS on the CSF biochemical profiles of patients with HCM. Our study indicated that CSF protein levels and WBC counts increased, while CSF glucose levels decreased, significantly in patients in the VPS group. This is consistent with the findings of previous studies [6, 7, 14]. Moreover, apparent changes in the CSF profiles of patients with HCM and a VPS led to a higher rate of misdiagnosis of tuberculous meningitis, inappropriate corticosteroid use, and increased inappropriate use of antibiotics/anti-tuberculosis drugs [14].
To date, the mechanisms underlying the tuberculous meningitis-like CSF profile in patients with VPS are unclear. First, there may be a predisposition to ‘paradoxical’ IRIS. HCM-related IRIS occurs in two forms: ‘paradoxical’ IRIS and unmasking IRIS. The former is characterized by initial improvement in clinical manifestations after antifungal therapy; however, deterioration occurs because of HAART-mediated immune restoration in patients with HCM. Severe IRIS exacerbates the clinical symptoms and signs of HCM, leading to severe disease [15]. In this study, clinical presentations and CSF profiles improved after VPS placement but were exacerbated after HAART initiation. Therefore, ‘paradoxical’ IRIS may have triggered changes in clinical presentations and CSF profiles. Second, placement of the shunting device may have increased CSF protein levels. Previous studies [16, 17] have suggested that CSF protein levels are increased by the placement of external drainage devices in patients with Alzheimer’s disease and are associated with trauma resulting from ventricular drain insertion. Therefore, we speculated that the placement of an external drainage device may have increased CSF protein levels. Third, the placement of an external drainage device may have stimulated the production of cytokines/chemokines, such as vascular endothelial growth factor, transferrin, and brain-derived protein, in CSF, leading to higher CSF protein levels [17–19].
This study suggested that intracranial hypertension, symptoms, and imaging findings were markedly improved after VPS placement in patients with HCM; however, the rates of misdiagnosis of tuberculous meningitis and corticosteroid use were higher in these patients. These results indicated that VPS placement had a potential impact on CSF profiles with long-term VPS use. To the best of our knowledge, this is the first study to describe the impact of VPS placement on changes in CSF profiles.
This study has some limitations. First, the sample size was small. Second, the precise mechanisms underlying increased CSF protein levels were not fully investigated. Larger studies focusing on the pathogenesis of increased CSF protein levels after VPS placement are required to obtain more reliable data. A comprehensive understanding of the pathogenesis of increased CSF protein levels after VPS placement will help clinicians make rational decisions regarding the proper management of these patients. Third, our study only included Chinese patients, which may affect the generalizability of our results. International prospective multicenter studies are required to obtain more accurate data.