Structural alterations of the pyramidal pathway in schizoid and schizotypal cluster A personality disorders.

AIM: Schizoid (ScPD) and Schizotypal (SPD) personality disorders are rare and severe disorders. They are associated with high liability to schizophrenia and present an attenuated form of its negative symptoms, which are considered a putative endophenotype for schizophrenia. The trans-diagnostic study of negative symptoms in non-psychotic populations such as ScPD/SPD might provide useful markers of a negative-symptom domain; however, little is known about their neurobiological substrates. The aim of the study was to investigate differences in gray and white matter volumes in subjects with ScPD/SPD compared to a group of healthy controls. METHODS: Structural magnetic resonance images were obtained from 20 never-psychotic subjects with ScPD/SPD and 28 healthy controls. Resulting values from clusters of differences were correlated in patients with relevant clinical variables (O-LIFE scale). RESULTS: ScPD/SPD presented greater bilateral white matter volume compared to healthy controls in the superior part of the corona radiata, close to motor/premotor regions, which correlated with the O-LIFE subtest of cognitive disorganization. No differences were found in regional gray matter or global gray/white matter volumes. CONCLUSION: Greater volumes in motor pathways might relate to cognitive symptoms and motor alterations commonly present in schizophrenia-related disorders. Given the established link between motor signs and psychosis, structural alterations in motor pathways are suggested as a putative biomarker of a negative-symptom domain in psychosis subject to further testing.

Other noninfectious inflammatory disorders.

Idiopathic inflammatory-demyelinating diseases (IIDDs) represent a broad spectrum of central nervous system (CNS) disorders, including monophasic, multiphasic, and progressive disorders that range from highly localized forms to multifocal or diffuse variants. In addition to the classic multiple sclerosis (MS) phenotypes, several MS variants have been described, which can be differentiated on the basis of severity, clinical course, and lesion distribution. Other forms of IIDD are now recognized as distinct entities and not MS variants, such as acute disseminated encephalomyelitis, and neuromyelitis optica spectrum disorders. The CNS can also be affected by a variety of inflammatory diseases. These include primary angiitis of the CNS (PACNS), a rare disorder specifically targeting the CNS vasculature, and various systemic conditions which, among other organs and systems, can also affect the CNS, such as systemic vasculitis and sarcoidosis. The diagnosis of PACNS is difficult, as this condition may be confused with reversible cerebral vasoconstriction syndrome (RCVS), a term comprising a group of conditions characterized by prolonged but reversible vasoconstriction of the cerebral arteries. Magnetic resonance imaging of the brain and spine is the radiologic technique of choice for diagnosing these disorders, and, together with the clinical and laboratory findings, enables a prompt and accurate diagnosis.

Idiopathic inflammatory demyelinating diseases of the brainstem.

Idiopathic inflammatory demyelinating diseases (IIDDs) represent a broad spectrum of central nervous system disorders that can be differentiated on the basis of severity, clinical course, and lesion distribution, as well as imaging, laboratory and pathologic findings. The spectrum includes monophasic, multiphasic, and progressive disorders, ranging from highly localized forms to multifocal or diffuse variants. All forms of IIDDs may affect the brainstem usually in association with involvement of other areas of the central nervous system but only rarely in isolation. In this article, we will review the main clinical and imaging features of the different IIDDs which may involve the brainstem.