Exploring the frequency and clinical background of the "zebra sign" in amyotrophic lateral sclerosis and multiple system atrophy.

In amyotrophic lateral sclerosis (ALS), the "zebra sign" in the precentral gyrus on phase difference enhanced magnetic resonance imaging (PADRE) recently has been reported as a possible imaging biomarker for upper motor neuron (UMN) involvement. A previous study has shown that the "zebra sign" allowed us to differentiate patients with ALS from healthy subjects with excellent accuracy. We validated the usefulness of the sign for differentiating patients with ALS from healthy subjects and investigated whether the "zebra sign" can be observed other neurodegenerative disorders with UMN involvement. The "zebra sign" on PADRE was assessed in 26 patients with ALS, 26 with multiple system atrophy (MSA) and 26 healthy controls, and the sign was observed in 50%, 23%, and no subjects, respectively. ALS patients with the "zebra sign" demonstrated a higher UMN burden score than those without the sign. The "zebra sign" on PADRE is not specific to ALS, also present in MSA, but might reflect the degeneration of the UMN within the motor cortex in neurodegenerative disorders.

Thalamic involvement determined using VSRAD advance on MRI and easy Z-score analysis of 99mTc-ECD-SPECT in Gerstmann-Sträussler-Scheinker syndrome with P102L mutation.

Gerstmann-Sträussler-Scheinker syndrome caused by the P102L mutation in the prion protein gene (GSS102) is usually characterized by the onset of slowly progressive cerebellar ataxia, with dementia occurring much later. Because of the relatively long disease course and the prominence of progressive cerebellar ataxia in the early stage, GSS102 is often misdiagnosed as other neurodegenerative disorders. We present two cases of genetically proven GSS102L, both of which present with atrophy and decreased blood flow of the thalamus as determined by voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) advance software and easy Z-score analysis for 99mTc-ethyl cysteinate dimer-SPECT, respectively. These thalamic abnormalities have not been fully evaluated to date, and detecting them might be useful for differentiating GSS102 from other neurodegenerative disorders.

Thalamic hypoperfusion and disrupted cerebral blood flow networks in idiopathic generalized epilepsy: Arterial spin labeling and graph theoretical analysis.

PURPOSE: The aim of this study was to investigate interictal cerebral blood flow (CBF) distributions and graph theoretical networks in idiopathic generalized epilepsy (IGE) using arterial spin labeling (ASL) imaging and anatomical covariance methods of graph theoretical analysis. MATERIAL AND METHODS: We recruited 19 patients with IGE and 19 age-/gender-matched healthy controls. Their CBF images were obtained by pseudo-continuous ASL imaging and compared using statistical parametric mapping 8 software (SPM8) and Graph Analysis Toolbox (GAT). RESULTS: The ASL imaging could detect interictal hypoperfusion in the thalamus, upper midbrain, and left cerebellum in IGE. Additionally, the graph theoretical analyses revealed characteristic findings of the CBF network of IGE, including significantly reduced resilience to attacks and changes of regional clustering especially in the bilateral temporo-occipital areas and lateral frontal lobes. There was no significance in the comparisons of network metrics. CONCLUSION: These findings could contribute to a better understanding of the pathophysiology of IGE.

Usefulness of SWI for the Detection of Iron in the Motor Cortex in Amyotrophic Lateral Sclerosis.

PURPOSE: The purpose of the present retrospective study was to evaluate the sensitivity of susceptibility-weighted imaging (SWI) compared to conventional spin-echo T2-weighted and T2*-weighted images in detecting iron deposition in the motor cortex of amyotrophic lateral sclerosis (ALS) patients in comparison with age-matched normal controls. We also investigated the etiology of the low signal referring to the pathology of one autopsy case. METHODS: This retrospective magnetic resonance (MR) study included 23 ALS patients and 28 age-matched normal controls. The signal intensity of the motor cortex was scored by SWI, conventional T2-weighted images and T2*-weighted images. A postmortem study of one patient was also performed. RESULTS: On SWI, there was a significant difference between the precentral cortical signal intensity scores in the ALS patients and the controls (P < .0001). The total scores of signal intensities of the precentral cortex were positively correlated with age in the normal controls (r = .494), but no correlation was observed in the ALS patients. The postmortem study showed intensely stained microglias and macrophages after antiferritin antibody staining in the precentral cortices. CONCLUSIONS: Decreased signal intensity of the motor cortex on SWI may serve a useful role in ALS diagnoses, particularly in young patients. MR images were also helpful for speculating on the etiology of ALS.