Patterns of brain atrophy in Parkinson's disease, progressive supranuclear palsy and multiple system atrophy.

BACKGROUND AND PURPOSE: Quantitative analysis of brain atrophy may be useful in differentiating Parkinson's Disease (PD) from Progressive Supranuclear Palsy (PSP) and parkinsonian variant of Multiple System Atrophy (MSA-P); the aim of this study was to identify the volumetric differences of subcortical structures in patients with PD, PSP and MSA-P using a novel and validated fully-automated whole brain segmentation method. METHODS: Volumetric MRIs were obtained in 72 patients with PD, 32 patients with PSP, 15 patients with MSA-P, and in 46 control subjects. Subcortical volume was measured automatically by FreeSurfer. Multivariate analysis of covariance, adjusted for intracranial volume (ICV), sex and age, was used to explore group differences. RESULTS: No volumetric differences were found between PD and controls group; otherwise the volumes of the cerebellum, the thalamus, the putamen, the pallidum, the hippocampus, and the brainstem were significantly reduced in PSP and MSA-P compared to patients with PD and control subjects. PSP and MSA-P patients only differed in thalamus volume which was smaller in PSP group (p < 0.001). Moreover, patients with PSP and MSA-P showed a ventricular system (including lateral, third and fourth ventricles) larger than that detected in PD and controls (p < 0.001). CONCLUSIONS: Volumetric data obtained with automated segmentation of cerebral regions show a significant atrophy of different brain structures in parkinsonisms rather than in PD. Our study also demonstrates that the atrophy of the thalamus only occurs in PSP while the enlargement of the whole ventricular system characterizes both PSP and MSA-P.

Clinical, genetic and magnetic resonance findings in an Italian patient affected by L-2-hydroxyglutaric aciduria.

L-2-Hydroxyglutaric aciduria (L-2-HGA) is a neurometabolic disease characterized by the presence of elevated levels of 2-hydroxyglutaric acid in the plasma, cerebrospinal fluid and urine. Clinical features in this inherited condition consist of mental deterioration, ataxia and motor deficits with pyramidal and extrapyramidal symptoms and signs. L-2-HGA is caused by mutations in the L-2-HGDH gene which most probably encodes for a L-2-hydroxyglutarate dehydrogenase, a putative mitochondrial protein converting L-2-hydroxyglutarate to alphaketoglutarate. Here, we report a pathogenic nonsense mutation in the L-2-HGDH gene found for the first time in an Italian patient affected by L-2-HGA, reinforcing the previously described phenotype of this rare metabolic disease and confirming the data indicating that mutations in the L-2-HGDH gene cause L-2-HGA.

Complete oculomotor palsy caused by persistent trigeminal artery.

Primitive trigeminal artery (PTA) is the most frequent embryonic communication between the carotid and vertebro-basilar system. PTA is a pathophysiology phenomenon which has been implicated as a rare cause of cranial nerve dysfunction. We report the case of a 40-year-old woman who developed a complete oculomotor nerve palsy caused by a persistent ecstatic trigeminal artery. Brain MRI and MRA studies documented a neurovascular conflict between the oculomotor nerve and a PTA. To the best of our knowledge there is no report about complete third cranial nerve palsy NC due to a PTA. A role of this rare vascular condition is discussed.

Spinal glioneuronal tumor with neuropil-like islands and meningeal dissemination: histopathological and radiological study of a pediatric case.

Cerebral and spinal location of glioneuronal tumors have been recently described as a novel type of primary CNS neoplasia. A distinctive rare form of glioneuronal tumors with neuropil-like islands (GTNI) have been reported to occur in the adult cerebrum, whereas spinal GTNI localization is extremely rare. In the present report we describe a case of a 15-month-old child with a spinal GTNI of the cervical region and meningeal dissemination. Histologically the tumor was composed of round, small neurocytic-like cells arranged around eosinophilic neuropil cores and embedded in a diffuse fibrillar glial component forming prominent "rosetted" neuropil islands displaying strong immunoreactivity for neuronal markers. Cerebral GTNI shows abundant glial components not rarely exhibiting anaplastic features that justify their inclusion within the group of diffuse astrocytomas. In contrast, including our case, spinal GTNI do not show histological evidence of anaplastic features and exhibits a significant neuronal component that may imply considering these lesions in a separate group. Nevertheless, due to their exceptional rarity, the natural history of these lesions is not yet fully understood, but spinal GTNI seems to have an unfavorable clinical course despite their benign histopathological features, which must be taken into account for appropriate treatment and follow-up of the patient.

Comparison of different MR venography techniques for detecting transverse sinus stenosis in idiopathic intracranial hypertension.

Cerebral venous outflow abnormalities, as transverse sinuses (TSs) stenosis,may underlie a picture of idiopathic intracranial hypertension (IIH). To identify the best non-invasive MR venography (MRV) technique for exploring the disturbance of flow of TSs in IIH patients, we compared three dimensional phase contrast (3-DPC) MRV images, acquired with different velocity encodings (15 and 40 cm/s) with two-dimensional time-of-flight (2D-TOF) MR images in 6 subjects with IIH and 12 age-matched normal controls. In both groups, we also measured flow velocity in TSs by using single slice 2D-CINE PC acquisitions. In all subjects with IIH, 3D-PC showed marked flow disturbance in the mid-lateral portion of both TSs when velocity encoding (VENC) was set to 15 cm/s while only a slightly irregular flow in TSs was detected when VENC was set to 40 cm/s or when 2D-TOF was used. By contrast, 3D-PC (VENC 15 and 40) and 2D-TOF techniques were comparable in detecting TS signal flow in normal controls. Measures of flow velocity, by using 2D-CINE PC, revealed a three-fold increase of velocity at the level of the flow disturbance in IIH patients compared to normal controls (p<0.0001), suggesting a marked stenosis of mid-lateral portion of TSs in these patients. Setting the VENC to 15 cm/s on 3D-PC MRV may represent the best technical approach for visualizing disturbances of flow in TSs in subjects with symptoms suggestive of IIH.