10 most commonly asked questions about cerebrospinal fluid characteristics in demyelinating disorders of the central nervous system

[Differential diagnostics of autoimmune inflammatory spinal cord diseases]

Myelitis is an acute or subacute inflammatory syndrome of the spinal cord. Myelopathy, often used as a synonym and presenting with similar symptoms in clinical practice, can be caused by numerous, not primarily inflammatory etiologies and might also show a progressive disease course. Within the last decade the spectrum of autoimmune myelitis was significantly broadened as was the spectrum of diagnostic methods. Apart from the characteristic example of multiple sclerosis with short-length myelitis and neuromyelitis optica spectrum disorders with longitudinally extensive transverse myelitis, multiple rare but important differential diagnoses should also be considered. Magnetic resonance imaging and laboratory analyses of serum antibodies and cerebrospinal fluid are the most important diagnostic methods and are fundamental for rapid treatment decisions, subsequently with better prognosis. This article reviews representative diseases within the spectrum of autoimmune spinal cord diseases and their differential diagnoses.

[Clinical and biochemical characteristics of atypical variants of multiple sclerosis]

AIM

To study the clinical and biochemical features of atypical variants of multiple sclerosis (MS) (tumefactive demyelination (TD), Balo's concentric sclerosis (BCS)) and acute disseminated encephalomyelitis (ADEM)).

MATERIAL AND METHODS

Forty-two patients were studied, including 32 patients with atypical variants of MS (6 patients with BCS and 26 patients with TD) and 10 patients with ADEM. The control group included 20 healthy volunteers. Clinical characteristics and EDSS scores were evaluated. Antibodies to aquaporin 1 (AQP1-IgG), aquaporin 4 (AQP4-IgG), antibodies to myelin oligodendrocyte glycoprotein (MOG-IgG) and aquaporin 1 (AQP1) in serum and cerebrospinal fluid (CSF) were detected using ELISA.

RESULTS AND CONCLUSION

BCS and TD occurred both in isolation and comorbid with MS (in 50% of cases with BCS, 50% of cases with TD). Atypical symptoms of MS were detected in 50% of cases of CFS, 15.4% of cases of PD. The levels of CSF cytosis and CSF protein were not significantly different between the groups. The levels of AQP1-IgG, AQP4-IgG, AQP1, MOG-IgG in serum with BCS, TD and ADEM were significantly higher than in the control group. No significant differences were found between atypical variants of MS. A correlation between a high level of MOG-IgG and the EDSS score in BCS was shown. MOG-IgG may have a pathogenetic significance in BCS. Further studies of AQP1-IgG, AQP4-IgG and MOG-IgG in patients with atypical variants of MS are needed.

Diagnosis of multiple sclerosis

There is no pathognomonic symptom, sign, or paraclinical result that provides an unfailingly accurate diagnosis of multiple sclerosis (MS), and hence, MS remains largely a clinical diagnosis. However, being a clinical diagnosis does not mean that the diagnosis of MS is one of exclusion. Increasingly sophisticated guidelines and objective paraclinical findings are generally sufficient to allow the clinician to confirm or rule out the diagnosis with confidence. This article presents the most recent guidelines for using clinical, radiological, and other paraclinical information and the red flags that should alert the clinician to investigate other diagnostic possibilities.

A modern approach to CSF analysis: pathophysiology, clinical application, proof of concept and laboratory reporting

The CNS immune response often leads to characteristic interrelated biochemical changes in cerebrospinal fluid. Multiple analytes, i.e. cell count, cell differential, evaluation of barrier function and intrathecal IgG, IgA and IgM synthesis should be included in basic diagnostic workup. We describe the scientific background, laboratory investigations and characteristic patterns found with basic CSF analysis, based on the recommendations of the German cerebrospinal fluid society. The concept is substantiated by retrospectively analyzing data of 4026 paired CSF/serum samples. 53% of our samples presented with at least one or several combined abnormal findings. An intrathecal IgG, IgA or IgM immunoglobulin response (37%, n=1481) and a blood-CSF barrier dysfunction (37%; n=1473) were most frequent; followed by an elevated leukocyte cell count (25%; n=992). The immunoglobulin response showed an intrathecal production of IgG in 49% (n=731/1481), which was only detectable in isoelectric focusing in 27% (n=200/731). Intrathecal IgM (n=389) and IgA (n=361) synthesis presented with nearly equal frequency of 25% in samples with intrathecal immunoglobulin response. The immunoglobulin pattern showed a solitary one class reaction of IgG, IgA or IgM in 67%, a combined two class reaction of IgG/IgA, IgG/IgM or IgA/IgM synthesis in 16% and a combined three-class reaction of IgG, IgA and IgM in 17%. This approach generates valuable but numerous complex and interrelated biochemical data. We therefore developed a knowledge-based system combined with visual oriented laboratory output to transfer the information more effectively. This often uncovers typical patterns specific for distinct neurological diseases, is well accepted by our medical community documented by a 37% increase in external ordering.