Antonella Costa

SPG11: a consistent clinical phenotype in a family with homozygous spatacsin truncating mutation.

Hereditary spastic paraplegias (HSP) are a heterogeneous group of neurodegenerative disorders leading to progressive spasticity of the lower limbs. Here, we describe clinical and genetic features in an Italian family affected by autosomal recessive HSP (ARHSP) with mental impairment and thin corpus callosum (TCC). In both affected subjects, genetic analysis revealed the presence of a homozygous small deletion (733_734delAT) leading to a frameshift (M245VfsX) within the coding region of SPG11 gene, encoding spatacsin. This finding is the first independent confirmation that spatacsin loss of function mutations cause ARHPS-TCC.

Neuromelanin Imaging and Dopaminergic Loss in Parkinson's Disease

Parkinsons disease (PD) is a progressive neurodegenerative disorder in which the major pathologic substrate is a loss of dopaminergic neurons from the substantia nigra. Our main objective was to determine the correspondence between changes in the substantia nigra, evident in neuromelanin and iron sensitive magnetic resonance imaging (MRI), and dopaminergic striatal innervation loss in patients with PD. Eighteen patients and 18 healthy control subjects were included in the study. Using neuromelanin-MRI, we measured the volume of the substantia nigra and the contrast-to-noise-ratio between substantia nigra and a background region. The apparent transverse relaxation rate and magnetic susceptibility of the substantia nigra were calculated from dual-echo MRI. Striatal dopaminergic innervation was measured as density of dopamine transporter (DAT) by means of single-photon emission computed tomography and [123I] N-ω-fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl) tropane. Patients showed a reduced volume of the substantia nigra and contrast-to-noise-ratio and both positively correlated with the corresponding striatal DAT density. The apparent transverse relaxation rate and magnetic susceptibility values of the substantia nigra did not differ between patients and healthy controls. The best predictor of DAT reduction was the volume of the substantia nigra. Clinical and imaging correlations were also investigated for the locus coeruleus. Our results suggest that neuromelanin-MRI can be used for quantifying substantia nigra pathology in PD where it closely correlates with dopaminergic striatal innervation loss. Longitudinal studies should further explore the role of Neuromelanin-MRI as an imaging biomarker of PD, especially for subjects at risk of developing the disease.

Quantitative assessments of traumatic axonal injury in human brain: concordance of microdialysis and advanced MRI

Axonal injury is a major contributor to adverse outcomes following brain trauma. However, the extent of axonal injury cannot currently be assessed reliably in living humans. Here, we used two experimental methods with distinct noise sources and limitations in the same cohort of 15 patients with severe traumatic brain injury to assess axonal injury. One hundred kilodalton cut-off microdialysis catheters were implanted at a median time of 17 h (13-29 h) after injury in normal appearing (on computed tomography scan) frontal white matter in all patients, and samples were collected for at least 72 h. Multiple analytes, such as the metabolic markers glucose, lactate, pyruvate, glutamate and tau and amyloid-β proteins, were measured every 1-2 h in the microdialysis samples. Diffusion tensor magnetic resonance imaging scans at 3 T were performed 2-9 weeks after injury in 11 patients. Stability of diffusion tensor imaging findings was verified by repeat scans 1-3 years later in seven patients. An additional four patients were scanned only at 1-3 years after injury. Imaging abnormalities were assessed based on comparisons with five healthy control subjects for each patient, matched by age and sex (32 controls in total). No safety concerns arose during either microdialysis or scanning. We found that acute microdialysis measurements of the axonal cytoskeletal protein tau in the brain extracellular space correlated well with diffusion tensor magnetic resonance imaging-based measurements of reduced brain white matter integrity in the 1-cm radius white matter-masked region near the microdialysis catheter insertion sites. Specifically, we found a significant inverse correlation between microdialysis measured levels of tau 13-36 h after injury and anisotropy reductions in comparison with healthy controls (Spearmans r = -0.64, P = 0.006). Anisotropy reductions near microdialysis catheter insertion sites were highly correlated with reductions in multiple additional white matter regions. We interpret this result to mean that both microdialysis and diffusion tensor magnetic resonance imaging accurately reflect the same pathophysiological process: traumatic axonal injury. This cross-validation increases confidence in both methods for the clinical assessment of axonal injury. However, neither microdialysis nor diffusion tensor magnetic resonance imaging have been validated versus post-mortem histology in humans. Furthermore, future work will be required to determine the prognostic significance of these assessments of traumatic axonal injury when combined with other clinical and radiological measures.

Schilder's disease: non-invasive diagnosis? :A case report and review.

Schilder’s disease, or myelinoclastic diffuse sclerosis, is a rare disorder characterised by an inflammatory white matter plaque of demyelination. Clinical signs and symptoms might be atypical for early multiple sclerosis and at imaging the lesion is easily taken for a brain tumour. Regardless of the use of Poser’s criteria for clinical diagnosis of Schilder’s disease proposed in 1986, diagnostic difficulties are still present, as evidenced by the many reported cases in the English literature revised (Pubmed indexed, period 1998–2008). It clearly emerges that neuroradiological features, observable in additional magnetic resonance sequences are crucial, besides the consideration of Poser’s criteria, in differentiating between demyelinating lesions and brain tumours. A 29-year-old female patient is presented, where a careful evaluation of both the clinical and radiological features, which might have been at a first glance misleadingly suggestive for a brain tumour, allowed non-invasive diagnosis of Schilder’s disease.

Contrast mechanisms associated with neuromelanin-MRI.

To investigate the physical mechanisms associated with the contrast observed in neuromelanin MRI.

Racemose neurocysticercosis after chronic meningitis: effect of medical treatment

A patient affected by racemous neurocysticercosis, occurring 5 years after the onset of chronic meningitis and followed by sequential MRI studies, is described. After ventriculo-peritoneal shunt, he was successfully treated with Praziquantel and Albendazole. This case may contribute to understand the natural history of the disease and stress the efficacy of medical versus surgical treatment of this lifethreatening disease.

Meningo-cortical calcifying angiomatosis and celiac disease

A woman with ophthalmic migraine was found to have bilateral cerebellar and cerebral calcifications. She progressively developed severe intracranial hypertension, with swelling of the brain and downward transtentorial and tonsillar herniation. Because steroid treatment was ineffective, the right occipital pole was resected. Histological study demonstrated meningo-cortical calcifying angiomatosis. Within 2 months, brain swelling and papilledema disappeared. Subtle signs of malabsorption led to the hypothesis of celiac disease, confirmed by jejunal biopsy. Similar cerebral histological findings have been reported in the brain of two young patients affected by epilepsy and celiac disease. The association between cerebral calcifications and celiac disease is peculiar; the pathogenetic relationship is unknown.

Stem cell salvage of injured peripheral nerve

We previously developed a collagen tube filled with autologous skin-derived stem cells (SDSCs) for bridging long rat sciatic nerve gaps. Here we present a case report describing a compassionate use of this graft for repairing the polyinjured motor and sensory nerves of the upper arms of a patient. Preclinical assessment was performed with collagen/SDSC implantation in rats after sectioning the sciatic nerve. For the patient, during the 3-year follow-up period, functional recovery of injured median and ulnar nerves was assessed by pinch gauge test and static two-point discrimination and touch test with monofilaments, along with electophysiological and MRI examinations. Preclinical experiments in rats revealed rescue of sciatic nerve and no side effects of patient-derived SDSC transplantation (30 and 180 days of treatment). In the patient treatment, motor and sensory functions of the median nerve demonstrated ongoing recovery postimplantation during the follow-up period. The results indicate that the collagen/SDSC artificial nerve graft could be used for surgical repair of larger defects in major lesions of peripheral nerves, increasing patient quality of life by saving the upper arms from amputation.

A cortically blind patient with preserved visual imagery.

Background/ObjectiveThe loss or preservation of visual imagery in patients with cortical blindness may be helpful in resolving the controversial roles assigned by some researchers to the early visual cortex during the process of visual imagery. Patient and MethodsHere we report a patient with complete permanent cortical blindness coupled with denial of the blindness (Anton syndrome) as a result of bilateral occipital infarction. ResultsInterestingly, the patients ability to visualize objects, color, and spatial imagery was preserved, although cerebral computed tomography, magnetic resonance imaging, and positron emission tomography scans detected what was likely complete bilateral damage to the primary visual cortex. ConclusionsOur findings may support the hypothesis that the primary visual cortex, in which retinal spatial geometry is preserved, is not critical for visual imagery.

High-resolution quantitative imaging of the substantia nigra.

There is a growing interest in identifying neuroimaging-based biomarkers for Parkinsons disease (PD), a progressive neurodegenerative disorder in which the major pathologic substrate is the loss of pigmented dopaminergic neurons in the substantia nigra (SN). Recently, an MRI technique dubbed “neuromelanin-sensitive MRI” (NM-MRI), has been found to provide notable contrast between the SN and surrounding brain tissues with potential applications as biomarker of PD. The contrast in NM-MRI has been associated with magnetization transfer (MT) effects, and thus the goal of this study was to characterize the impact of MT on NM-MRI, and to demonstrate the feasibility of performing quantitative MT (qMT) imaging in human SN. The results of this study demonstrate that high-resolution rapid qMT imaging of the SN can be reliably obtained within reasonable scan times, thereby can be translatable into clinical practice.