[A neonate with a swelling in the floor of the mouth]. / Een pasgeborene met een zwelling in de mondbodem.

A significant swelling was seen in the floor of the mouth of a newborn girl. The girl could only drink with difficulty. On examination, a soft-elastic swelling was seen beneath the tongue. Ultrasonography and MRI showed a mass located above the hyoid bone. Upon the initial differential diagnosis of a dermoid cyst, an enucleation of the lesion was performed. Histopathological examination suggested a branchiogenic cyst or a digestive duplication cyst. Given the inconclusiveness of additional diagnostic examination, the lesion was diagnosed as a developmental cyst. Six months after enucleation, the infant girl's tongue motility was not restricted and there were no indications of a recurrence. This rare case illustrates the variety in differential diagnosis and the limitations of additional diagnostic examination.

Case report: persistently seronegative neuroborreliosis in an immunocompromised patient.

BACKGROUND: Infection with Borrelia burgdorferi sensu lato complex (B. b. sl) spirochetes can cause Lyme borreliosis, manifesting as localized infection (e.g. erythema migrans) or disseminated disease (e.g. Lyme neuroborreliosis). Generally, patients with disseminated Lyme borreliosis will produce an antibody response several weeks post-infection. So far, no case of neuroborreliosis has been described with persistently negative serology one month after infection. CASE PRESENTATION: We present a patient with a history of Mantle cell lymphoma and treatment with R-CHOP (rituximab, doxorubicine, vincristine, cyclofosfamide, prednisone), with a meningo-encephalitis, who was treated for a suspected lymphoma relapse. However, no malignant cells or other signs of malignancy were found, and microbial tests did not reveal any clues, including Borrelia serology. He did not recall being bitten by ticks, and a Borrelia PCR on CSF was negative. After spontaneous improvement of symptoms, he was discharged without definite diagnosis. Several weeks later, he was readmitted with a relapse of symptoms of meningo-encephalitis. This time however, a Borrelia PCR on CSF was positive, confirmed by two independent laboratories, and the patient received ceftriaxone upon which he partially recovered. Interestingly, during the diagnostic process of this exceptionally difficult case, a variety of different serological assays for Borrelia antibodies remained negative. Only P41 (flagellin) IgG was detected by blot and the Liaison IgG became equivocal 2 months after initial testing. CONCLUSIONS: To the best of our knowledge this is the first case of neuroborreliosis that is seronegative on repeated sera and multiple test modalities. This unique case demonstrates the difficulty to diagnose neuroborreliosis in severely immunocompromised patients. In this case, a delay in diagnosis was caused by broad differential diagnosis, an absent known history of tick bites, negative serology and the low sensitivity of PCR on CSF. Therefore, awareness of the diagnostic limitations to detect Borrelia infection in this specific patient category is warranted.

Brain endothelial cell expression of SPARCL-1 is specific to chronic multiple sclerosis lesions and is regulated by inflammatory mediators in vitro.

AIMS: Cell matrix modulating protein SPARCL-1 is highly expressed by astrocytes during CNS development and following acute CNS damage. Applying NanoLC-MS/MS to CSF of RRMS and SPMS patients, we identified SPARCL-1 as differentially expressed between these two stages of MS, suggesting a potential as CSF biomarker to differentiate RRMS from SPMS and a role in MS pathogenesis. METHODS: This study examines the potential of SPARCL-1 as CSF biomarker discriminating RRMS from SPMS in three independent cohorts (n = 249), analyses its expression pattern in MS lesions (n = 26), and studies its regulation in cultured human brain microvasculature endothelial cells (BEC) after exposure to MS-relevant inflammatory mediators. RESULTS: SPARCL-1 expression in CSF was significantly higher in SPMS compared to RRMS in a Dutch cohort of 76 patients. This finding was not replicated in 2 additional cohorts of MS patients from Sweden (n = 81) and Switzerland (n = 92). In chronic MS lesions, but not active lesions or NAWM, a vessel expression pattern of SPARCL-1 was observed in addition to the expression by astrocytes. EC were found to express SPARCL-1 in chronic MS lesions, and SPARCL-1 expression was regulated by MS-relevant inflammatory mediators in cultured human BEC. CONCLUSIONS: Conflicting results of SPARCL-1's differential expression in CSF of three independent cohorts of RRMS and SPMS patients precludes its use as biomarker for disease progression. The expression of SPARCL-1 by BEC in chronic MS lesions together with its regulation by inflammatory mediators in vitro suggest a role for SPARCL-1 in MS neuropathology, possibly at the brain vascular level.

Heat shock protein expression in cerebral X-linked adrenoleukodystrophy reveals astrocyte stress prior to myelin loss.

AIMS: X-linked adrenoleukodystrophy (X-ALD) is a genetic white matter disorder in which demyelination occurs due to accumulation of very long-chain fatty acids. Inflammation in the brain white matter is a hallmark of the pathology of cerebral X-ALD, but the underlying pathogenic mechanisms are still largely unknown. In other inflammatory demyelinating disorders, such as multiple sclerosis, the expression of heat shock proteins (HSPs) in combination with interferon-γ (IFN-γ) has been suggested to play a prominent role in the initiation of demyelination and inflammation. We therefore investigated these pathways in X-ALD lesions. METHODS: By immunohistochemistry, we examined the expression of small HSPs (HSPB1, HSPB5, HSPB6, HSPB8) and higher molecular weight HSPs (HSPA, HSPD1), and the expression of elements of the IFN-γ pathway on autopsy material of five patients with X-ALD. RESULTS: The expression of the larger HSPs, HSPA and HSPD1, as well as small HSPs is increased in X-ALD lesions compared with normal-appearing white matter. Such upregulation can already be detected before demyelination and inflammation occur, and it is predominant in astrocytes. The IFN-γ pathway does not seem to play a leading role in the observed inflammation. CONCLUSIONS: The finding that astrocytes show signs of cellular stress before demyelination suggests that they play a major role early in the pathogenesis of cerebral X-ALD, and may therefore be involved in the initiation of inflammation and demyelination.

Extracellular vesicles as modulators of cell-to-cell communication in the healthy and diseased brain.

Homeostasis relies heavily on effective cell-to-cell communication. In the central nervous system (CNS), probably more so than in other organs, such communication is crucial to support and protect neurons especially during ageing, as well as to control inflammation, remove debris and infectious agents. Emerging evidence indicates that extracellular vesicles (EVs) including endosome-derived exosomes and fragments of the cellular plasma membrane play a key role in intercellular communication by transporting messenger RNA, microRNA (miRNA) and proteins. In neurodegenerative diseases, secreted vesicles not only remove misfolded proteins, but also transfer aggregated proteins and prions and are thus thought to perpetuate diseases by 'infecting' neighbouring cells with these pathogenic proteins. Conversely, in other CNS disorders signals from stressed cells may help control inflammation and inhibit degeneration. EVs may also reflect the status of the CNS and are present in the cerebrospinal fluid indicating that exosomes may act as biomarkers of disease. That extracellular RNA and in particular miRNA, can be transferred by EV also indicates that these vesicles could be used as carriers to specifically target the CNS to deliver immune modulatory drugs, neuroprotective agents and anti-cancer drugs. Here, we discuss the recent evidence indicating the potential role of exosomes in neurological disorders and how knowledge of their biology may enable a Trojan-horse approach to deliver drugs into the CNS and treat neurodegenerative and other disorders of the CNS.