Myeloid microvesicles in cerebrospinal fluid are associated with myelin damage and neuronal loss in mild cognitive impairment and Alzheimer disease.

OBJECTIVES: We have described cerebrospinal fluid (CSF) myeloid microvesicles (MVs) as a marker of microglia activation during neuroinflammation in Alzheimer disease (AD), and characterized their ability to produce toxic amyloid ß1-42 (Aß1-42 ) oligomers from aggregated or soluble substrate. The aim of this study is to investigate the association of CSF myeloid MVs with neuroimaging, clinical, and paraclinical data in AD and mild cognitive impairment (MCI). METHODS: We collected CSF from 106 AD patients, 51 MCI patients, and 29 neurologically healthy controls. We examined CSF myeloid MV content and AD markers. A subgroup of 34 AD and 21 MCI patients underwent structural and diffusion tensor MRI. RESULTS: Higher levels of myeloid MVs were found in the CSF of AD patients and MCI patients converting within 3 years relative to controls, but also, at a lower level, in MCI patients not converting to AD. CSF myeloid MVs were associated with Tau but not with Aß1-42 CSF levels. CSF MVs levels correlated with white matter (WM) tract damage in MCI, and with hippocampal atrophy in AD. INTERPRETATION: Microglial MVs are neurotoxic and myelinotoxic in the presence of Aß1-42 . CSF myeloid MVs, mirroring microglia activation and MV release, are associated with WM damage in MCI and hippocampal atrophy in AD. This suggests that hippocampal microglia activation, in the presence of Aß1-42 in excess, produces neurotoxic and oligodendrotoxic oligomers that, through WM tract damage, spread disease to neighboring and connected areas, causing local microglia activation and propagation of disease through the same sequence of events. Ann Neurol 2014;76:813-825.

Vitamin D levels and risk of multiple sclerosis in patients with clinically isolated syndromes.

BACKGROUND: Growing evidence suggests that vitamin D deficiency may be one of the most important environmental factors for the development of multiple sclerosis (MS). OBJECTIVES: The objectives of this paper are to evaluate serum 25-hydroxyvitamin D (25(OH)D) levels in patients with clinically isolated syndromes (CIS) and to examine whether they are related to MS risk. METHODS: This is a retrospective study of 100 CIS patients hospitalized from 2000 to 2009 at San Raffaele Hospital, Milan, Italy. We evaluated baseline 25(OH)D level as well as clinical, brain magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) data. RESULTS: A total of 52% of CIS patients had vitamin D deficiency (25(OH)D < 50 nmol/l). During follow-up (median: 7.17 years), 55 patients developed clinically definite MS (CDMS). Patients with very low (< 10th percentile) and low (< 25th percentile) 25(OH)D levels were particularly at risk of CDMS (HRs (95% CIs): 2.12 (0.91-4.96) and 1.61 (0.85-3.03), respectively), while no further reduction in the HRs of disease was observed at high levels of 25(OH)D. This association was even stronger after adjustment for additional risk factors for CDMS development (HRs (95% CIs) for 25(OH)D levels < 10th and 25th percentiles: 3.34 (1.32-8.45) and 2.04 (0.96-4.36), respectively). CONCLUSION: Low serum vitamin D is associated with increased MS risk in patients with CIS.

Myeloid microvesicles are a marker and therapeutic target for neuroinflammation.

OBJECTIVE: Microvesicles (MVs) have been indicated as important mediators of intercellular communication and are emerging as new biomarkers of tissue damage. Our previous data indicate that reactive microglia/macrophages release MVs in vitro. The aim of the study was to evaluate whether MVs are released by microglia/macrophages in vivo and whether their number varies in brain inflammatory conditions, such as multiple sclerosis (MS). METHODS: Electron and fluorescence microscopy and flow cytometry were used to detect myeloid MVs in the cerebrospinal fluid (CSF) of healthy controls, MS patients, and rodents affected by experimental autoimmune encephalomyelitis (EAE), the animal model of MS. RESULTS: Myeloid MVs were detected in CSF of healthy controls. In relapsing and remitting EAE mice, the concentration of myeloid MVs in the CSF was significantly increased and closely associated with disease course. Analysis of MVs in the CSF of 28 relapsing patients and 28 patients with clinical isolated syndrome from 2 independent cohorts revealed higher levels of myeloid MVs than in 13 age-matched controls, indicating a clinical value of MVs as a companion tool to capture disease activity. Myeloid MVs were found to spread inflammatory signals both in vitro and in vivo at the site of administration; mice impaired in MV shedding were protected from EAE, suggesting a pathogenic role for MVs in the disease. Finally, FTY720, the first approved oral MS drug, significantly reduced the amount of MVs in the CSF of EAE-treated mice. INTERPRETATION: These findings identify myeloid MVs as a marker and therapeutic target of brain inflammation.

Refractory migraine: the role of the physician in assessment and treatment of a problematic disease.

Patients affected by chronic forms of headache are often very difficult to treat. Refractory patients are so defined when adequate trials of specific drugs (for acute or prophylactic treatment) failed both to reduce the burden of disease and to improve headache-related quality of life. An escalating approach is suggested to test different kinds of therapies. All comorbid factors should be addressed. More invasive modalities (such as neurostimulation) or promising approaches such as repetitive transcranial magnetic stimulation (rTMS) could be a future major step as third line therapies.

From neuroimaging to clinical setting: what have we learned from migraine pain?

In the last 15 years, the neuroimaging of patients suffering from migraine with or without aura has improved our understanding of the mechanisms underlying the pathophysiology of the disease. A great number of studies based on modern imaging techniques, such as structural imaging and functional imaging emphasize that in migraine patients suffering from repetitive pain attacks, both significant abnormalities of function and diffuse structural changes of brain white and gray matter become striking features of the disease. The hypothesis that migraine pain is due to a global brain disorder with substantial brainstem involvement leading to secondary blood flow changes in the posterior circulation is reinforced by several elegant studies. Clinical application of functional imaging findings in migraine is yet to be considered, since the specificity of some results has to be determined. Nevertheless, functional MRI techniques have a vast potential for exploring the pathophysiology of pain in migraine patients.

Delayed diagnosis in pediatric headache: an outpatient Italian survey.

OBJECTIVE: The aim of this prospective study is to assess the time lapse between the onset of recurring headache and the correct diagnosis in a cohort of pediatric patients attending an Italian children's headache center for the first time. METHODS: One hundred and one patients and parents, referred to the Pediatric Headache Centre of San Raffaele Hospital in Milan, Italy, underwent a semi-structured interview to ascertain features of headache since onset (clinical and family history, presence of childhood periodic syndromes, previously undergone instrumental exams and specialists' examinations before the correct diagnosis, past and current treatment). All patients were evaluated by expert neurologists and their headache was classified according to the International Classification of Headache Disorders II (2004). RESULTS: The median time delay from the onset of the first episode of recurrent headache to definite diagnosis was 20 months (interquartile range 12 to 36 months). A correlation with younger age and a more delayed headache diagnosis was found (r Spearman = 0.25; P = .039). An association between diagnostic delay and positive family history (median 24 months [12 to 48] vs 12 [6 to 24]; P = .014) or female gender (median 18 months [12 to 42] vs. 12 [5 to 30]; P trend = .070) was also evident. Notably, 76 out of 101 patients referred to our Center received an appropriate diagnosis according to International Classification of Headache Disorders II at the time of our visit only. Of note, up to 21% of this group were previously misdiagnosed (for epilepsy 43%, sinusitis 38%, or other diseases 19%), a fact that contributed to a longer time of clinical assessment (median 39 months) before reaching a correct diagnosis. The other group of 80 patients (79%) did not receive a specific diagnosis and treatment, and were not studied until their symptom became chronic and disabling. CONCLUSION: Pediatric headache is still under-diagnosed and not adequately considered as a health problem in the medical community as well as social settings. There is a need for educational programs regarding headache involving not only general practitioners, pediatricians, and neurologists, but also the general population. These are desirable in order to raise awareness of such a condition and, accordingly, treat children accurately.

Ocular pain: a neurological perspective.

Ocular pain and related symptoms are frequent manifestations of primary and secondary headache disorders. Neurologists are often the first physician to evaluate patients affected by these clinical features. The cause of eye pain may be attributed both to pathological disorders with abnormal neurologic and neuro-ophthalmologic findings and to diseases with no apparent eye disturbances. A thorough clinical approach is necessary for an appropriate diagnosis and a correct specific management.