Disorders of neuronal migration are a heterogeneous group of disorders of nervous system development. One of the most frequent disorders is lissencephaly, characterized by a paucity of normal gyri and sulci resulting in a 'smooth brain'. There are two pathologic subtypes: classical and cobblestone. Six different genes could be responsible for this entity (LIS1, DCX, TUBA1A, VLDLR, ARX, RELN), although co-delection of YWHAE gene with LIS1 could result in Miller-Dieker Syndrome. Heterotopia is defined as a cluster of normal neurons in abnormal locations, and divided into three main groups: periventricular nodular heterotopia, subcortical heterotopia and marginal glioneural heterotopia. Genetically, heterotopia is related to Filamin A (FLNA) or ADP-ribosylation factor guanine exchange factor 2 (ARFGEF2) genes mutations. Polymicrogyria is described as an augmentation of small circonvolutions separated by shallow enlarged sulci; bilateral frontoparietal form is characterized by bilateral, symmetric polymicrogyria in the frontoparietal regions. Bilateral perisylvian polymicrogyria results in a clinical syndrome manifested by mild mental retardation, epilepsy and pseudobulbar palsy. Gene mutations linked to this disorder are SRPX2, PAX6, TBR2, KIAA1279, RAB3GAP1 and COL18A1. Schizencephaly, consisting in a cleft of cerebral hemisphere connecting extra-axial subaracnoid spaces and ventricles, is another important disorder of neuronal migration whose clinical characteristics are extremely variable. EMX2 gene could be implicated in its genesis. Focal cortical dysplasia is characterized by three different types of altered cortical laminations, and represents one of most severe cause of epilepsy in children. TSC1 gene could play a role in its etiology. Conclusion: This review reports the main clinical, genetical and neuroradiological aspects of these disorders. It is hoped that accumulating data of the development mechanisms underlying the expanded network formation in the brain will lead to the development of therapeutic options for neuronal migration disorders.

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Central nervous system vasculitides in children may develop as a primary condition or secondary to an underlying systemic disease. Many vasculitides affect both adults and children, while some others occur almost exclusively in childhood. Patients usually present with systemic symptoms with single or multiorgan dysfunction. The involvement of central nervous system in childhood is not frequent and it occurs more often as a feature of subtypes like childhood polyarteritis nodosa, Kawasaki disease, Henoch Schönlein purpura, and Bechet disease. Primary angiitis of the central nervous system of childhood is a reversible cause of severe neurological impairment, including acute ischemic stroke, intractable seizures, and cognitive decline. The first line therapy of CNS vasculitides is mainly based on corticosteroids and immunosuppressor drugs. Other strategies include plasmapheresis, immunoglobulins, and biologic drugs. This paper discusses on current understanding of most frequent primary and secondary central nervous system vasculitides in children including a tailored-diagnostic approach and new evidence regarding treatment.

The association between migraine and stroke is still a dilemma for neurologists. Migraine is associated with an increased stroke risk and it is considered an independent risk factor for ischaemic stroke in a particular subgroup of patients. The pathogenesis is still unknown even if several studies report some common biochemical mechanisms between these two diseases. A classification of migraine-related stroke that encompasses the full spectrum of the possible relationship between migraine and stroke includes three main entities: coexisting stroke and migraine, stroke with clinical features of migraine, and migraine-induced stroke. The concept of migraine-induced stroke is well represented by migrainous infarction and it is described in the revised classification of the International Headache Society (IHS), representing the strongest demonstration of the relationship between ischaemic stroke and migraine. A very interesting common condition in stroke and migraine is patent foramen ovale (PFO) which could play a pathogenetic role in both disorders. The neuroradiological evidence of subclinical lesions most typical in the white matter and in the posterior artery territories in patients with migraine, opens a new field of research. In conclusion the association between migraine and stroke remains an open question. Solving the above mentioned issues is fundamental to understand the epidemiologic, pathogenetic and clinical aspects of migraine-related stroke.

Our results emphasize that multiple predisposing risk factors commonly predispose to paediatric stroke. In addition, the primary clinical presentation appeared to differ between the older and younger children: hemiparesis was the typical presentation in children <1 year of age while seizure predominated in older children.