JNS.jpgThe July issue of the Journal of the Neurological Sciences Vol 414 is now available online.

 

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Issue highlights

Cerebral vascular reactivity and the migraine-stroke relationship: A narrative review

Migraine, and especially migraine with aura, is associated with an increased risk of stroke and vascular events; however, the reasons for this association are unclear.

Several studies evaluated cerebral autoregulation and vasomotor reactivity in patients with migraine compared with non-migraineurs, with conflicting results. Our narrative review aimed at summarizing their results to find the most reliable evidence in the field.

Studies which used visual stimuli to evoke vascular responses consistently showed an increased vascular reactivity in migraineurs compared with non-migraineurs, while studies which used systemic stimuli such as hyper- or hypocapnia showed inconsistent results. Therefore, central neural mechanisms might be more important than peripheral vascular mechanisms in determining the cerebral vascular responses of patients with migraine. However, a large body of evidence supports the existence of peripheral vascular dysfunction in patients with migraine.

Further studies are needed to explain the complex interactions between central neural and peripheral vascular mechanisms in determining migraine and its vascular risk. Migraine preventive treatments, and especially the most recent ones with a peripheral action, might provide important insights in this field.


The neurology of COVID-19 revisited: A proposal from the Environmental Neurology Specialty Group of the World Federation of Neurology to implement international neurological registries

Open Access

A comprehensive review of the neurological disorders reported during the current COVID-19 pandemic demonstrates that infection with SARS-CoV-2 affects the central nervous system (CNS), the peripheral nervous system (PNS) and the muscle.

iStock 1218372794 covid 19 and neuronCNS manifestations include: headache and decreased responsiveness considered initial indicators of potential neurological involvement; anosmia, hyposmia, hypogeusia, and dysgeusia are frequent early symptoms of coronavirus infection. Respiratory failure, the lethal manifestation of COVID-19, responsible for 264,679 deaths worldwide, is probably neurogenic in origin and may result from the viral invasion of cranial nerve I, progressing into rhinencephalon and brainstem respiratory centers.

Cerebrovascular disease, in particular large-vessel ischemic strokes, and less frequently cerebral venous thrombosis, intracerebral hemorrhage and subarachnoid hemorrhage, usually occur as part of a thrombotic state induced by viral attachment to ACE2 receptors in endothelium causing widespread endotheliitis, coagulopathy, arterial and venous thromboses.

Acute hemorrhagic necrotizing encephalopathy is associated to the cytokine storm. A frontal hypoperfusion syndrome has been identified. There are isolated reports of seizures, encephalopathy, meningitis, encephalitis, and myelitis.

The neurological diseases affecting the PNS and muscle in COVID-19 are less frequent and include Guillain-Barré syndrome; Miller Fisher syndrome; polyneuritis cranialis; and rare instances of viral myopathy with rhabdomyolysis.

The main conclusion of this review is the pressing need to define the neurology of COVID-19, its frequency, manifestations, neuropathology and pathogenesis.

On behalf of the World Federation of Neurology we invite national and regional neurological associations to create local databases to report cases with neurological manifestations observed during the on-going pandemic. International neuroepidemiological collaboration may help define the natural history of this worldwide problem.


Case-control association study of rare nonsynonymous variants of SCN1A and KCNQ2 in acute encephalopathy with biphasic seizures and late reduced diffusion

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized by prolonged febrile seizures at onset and subsequent damage to the cerebral cortex of infants and children. The pathogenesis is suspected to be excitotoxicity leading to neuronal death. SCN1A and KCNQ2 are causative genes of genetic epilepsy including Dravet syndrome and Ohtahara syndrome.

Here a case-control rare-variant association study of the two genes in AESD is conducted. The study provides statistical evidence of an association between SCN1A and AESD for the first time, and established SCN1A as one of the susceptibility genes for AESD.


Cytokine profile during pregnancy predicts relapses during pregnancy and postpartum in multiple sclerosis

This study explores the serum cytokine profile associated with disease activity during pregnancy and postpartum in MS, and to assess any potential biomarkers predicting the occurrence of relapses during this period.

MS patients with no relapses during pregnancy and puerperium showed an early triggering of a tolerogenic innate immune response evidenced by high serum Activin-A concentrations during the first trimester of pregnancy. Thus, serum Activin-A can be a useful biomarker to predict clinical activity during this period.