OBJECTIVE: To explore plastic changes in the red nucleus (RN) of stroke patients with severe corticospinal tract (CST) injury as a compensatory mechanism for recovery of hand function. METHODS: The moderate group (MG) comprised 5 patients with synergistic hand grasp movement combined with limited extension, and the severe group (SG) included 5 patients with synergistic hand grasp movement alone. The control group (CG) included 5 healthy subjects. Motor assessment was measured by Motricity Index (MI). Diffusion tensor imaging was analyzed using fractional anisotropy (FA) and radial diffusivity (RD) in the individual regions of interest (ROIs)—bilateral internal capsule and anterior pons for CST injury and bilateral RN for rubrospinal tract (RST) injury. RESULTS: The SG showed a significantly lower MI score than the MG mainly due to differences in hand subscores. Significantly reduced FA was observed in both MG and SG compared with CG, while SG showed increased MD and RD in the affected ROIs of CST, and increased FA on the unaffected side compared with CG. However, in the RN ROI, a significantly increased FA and decreased RD on the unaffected side similar to the affected side were found only in the SG. The relative index of FA was lower and RD in SG was higher than in CG in RST. CONCLUSION: The diffusion metrics of RST showed changes in patients with severe CST injury, suggesting that RST may play a role in the recovery of hand function in patients with severe CST injury.
Anisotropy ; Diffusion Tensor Imaging ; Diffusion* ; Extrapyramidal Tracts ; Hand ; Hand Strength ; Healthy Volunteers ; Humans ; Internal Capsule ; Neuronal Plasticity ; Paraplegia ; Plastics ; Pons ; Pyramidal Tracts* ; Recovery of Function ; Red Nucleus* ; Stroke* ; Upper Extremity

BACKGROUND: Quantitative susceptibility mapping (QSM) has been used to measure iron accumulation in the deep nuclei of patients with Parkinson's disease (PD). This study examined the relationship between non-motor symptoms (NMSs) and iron accumulation in the deep nuclei of patients with PD. METHODS: The QSM data were acquired from 3-Tesla magnetic resonance imaging (MRI) in 29 patients with early PD and 19 normal controls. The Korean version of the NMS scale (K-NMSS) was used for evaluation of NMSs in patients. The patients were divided into high NMS and low NMS groups. The region-of-interest analyses were performed in the following deep nuclei: red nucleus, substantia nigra pars compacta, substantia nigra pars reticulata, dentate nucleus, globus pallidus, putamen, and head of the caudate nucleus. RESULTS: Thirteen patients had high NMS scores (total K-NMSS score, mean = 32.1), and 16 had low NMS scores (10.6). The QSM values in the deep were not different among the patients with high NMS scores, low NMS scores, and controls. The QSM values were not correlated linearly with K-NMSS total score after adjusting the age at acquisition of brain MRI. CONCLUSION: The study demonstrated that the NMS burdens are not associated with iron accumulation in the deep nuclei of patients with PD. These results suggest that future neuroimaging studies on the pathology of NMSs in PD should use more specific and detailed clinical tools and recruit PD patients with severe NMSs.
Basal Ganglia ; Brain ; Caudate Nucleus ; Cerebellar Nuclei ; Globus Pallidus ; Head ; Humans ; Iron* ; Magnetic Resonance Imaging ; Neuroimaging ; Parkinson Disease* ; Pars Compacta ; Pars Reticulata ; Pathology ; Putamen ; Red Nucleus

Acute Japanese encephalitis (JE) is an endemic viral infectious disease in various parts of Far East and Southeast Asian countries including Korea. Bilateral thalami are the most common involving sites in JE. Other areas including the basal ganglia, substantia nigra, red nucleus, pons, cerebral cortex and cerebellum may be also involved. We report an extremely unusual brain diffusion-weighted MR imaging (DWI) findings in a 53-year-old man with serologically proven JE involving unilateral deep gray matter and temporal lobe, which shows multifocal high signal intensities in left thalamus, left substantia nigra, left caudate nucleus and left medial temporal cortex on T2-weighted image and DWI with iso-intensity on apparent diffusion coefficient (ADC) map.
Asian Continental Ancestry Group* ; Basal Ganglia ; Brain ; Caudate Nucleus ; Cerebellum ; Cerebral Cortex ; Communicable Diseases ; Diffusion ; Encephalitis, Japanese* ; Far East ; Gray Matter* ; Humans ; Korea ; Magnetic Resonance Imaging* ; Middle Aged ; Pons ; Red Nucleus ; Substantia Nigra ; Temporal Lobe* ; Thalamus

BACKGROUND AND PURPOSE: Previous T2 relaxometry studies have provided evidence for regional brain iron deficiency in patients with restless legs syndrome (RLS). Measurement of the iron content in several brain regions, and in particular the substantia nigra (SN), in early- and late-onset RLS patients using T2 relaxometry have yielded inconsistent results. In this study the regional iron content was assessed in patients with early- and late-onset RLS using magnetic resonance imaging (MRI), and compared the results with those in controls. METHODS: Thirty-seven patients with idiopathic RLS (20 with early onset and 17 with late onset) and 40 control subjects were studied using a 3.0-tesla MRI with a gradient-echo sampling of free induction decay and echo pulse sequence. The regions of interest in the brain were measured independently by two trained analysts using software known as medical image processing, analysis, and visualization. The results were compared and a correlation analysis was conducted to investigate which brain areas were related to RLS clinical variables. RESULTS: The iron index in the SN was significantly lower in patients with late-onset RLS than in controls (p=0.034), while in patients with early-onset RLS there was no significant difference. There was no significant correlation between the SN iron index of the late-onset RLS group and clinical variables such as disease severity. CONCLUSIONS: Late-onset RLS is associated with decreased iron content in the SN. This finding supports the hypothesis that regional brain iron deficiency plays a role in the pathophysiology of late-onset RLS.
Brain* ; Humans ; Iron ; Magnetic Resonance Imaging* ; Red Nucleus ; Restless Legs Syndrome* ; Substantia Nigra

Holmes' tremor is a condition characterized by a mixture of postural, rest, and action tremors due to midbrain lesions in the vicinity of the red nucleus. Hypertrophic olivary degeneration (HOD) is a rare type of neuronal degeneration involving the dento-rubro-olivary pathway and may present clinically as Holmes tremor. We report on a 59-year-old female patient who developed Holmes tremor in association with bilateral HOD, following brain stem hemorrhage.
Brain Stem* ; Female ; Hemorrhage* ; Humans ; Mesencephalon ; Middle Aged ; Neurons ; Olivary Nucleus ; Red Nucleus ; Tremor*

OBJECTIVE: The aim of this study was to evaluate the differences in normal brain MRI findings between under 3.0 Tesla (T) and 1.5T MRI conditions with the use of the fluid attenuated inversion recovery (FLAIR) sequences. MATERIALS AND METHODS: Eleven normal adults underwent imaging with the use of the FLAIR sequences on both 1.5T and 3.0T scanners. Two neuroradiologists compared the signal intensity (SI) of the centrum semiovale (CS), pulvinar thalami (PT) and normal iron deposit structures (IDSs) on the 3.0T and 1.5T FLAIR images, and they evaluated three MRI findings qualitatively: high SI of CS; low SI of PT; low SI of IDS. We also evaluated signal-to-noise ratios (SNRs) for the CS, PT, red nucleus and cerebellar dentate nucleus on the FLAIR images. RESULTS: Based on qualitative analyses, the 3.0T FLAIR images showed all three MRI findings for all cases. Low SI for the PT in seven cases (64%), high SI of the CS in one case (9%) and low SI of the cerebellar dentate nucleus in one case (9%) were visualized only on 3.0T FLAIR images. The mean SNRs of the PT, red nucleus and dentate nucleus in patients where 3.0T FLAIR imaging was performed were significantly lower as compared with the SNRs on 1.5T FLAIR images. The SNR of the CS was not significantly different between under the two magnetic field strengths (p > 0.05). CONCLUSION: We have demonstrated that normal, high and low SIs of the CS, PT and IDS on 3.0T FLAIR images were depicted more frequently and more prominently as compared with those on 1.5T FLAIR images in normal adult brains.
Adult ; Aged ; Brain/*anatomy & histology ; Cerebellar Nuclei/anatomy & histology ; Female ; Humans ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Pulvinar/anatomy & histology ; Red Nucleus/anatomy & histology

AIMTo explore an accurate neurophysiological technique that demonstrates small functional differences after spinal cord injury and assesses therapeutic interventions.

METHODSA modified weight drop (WD) technique was used at T8 in rats to build graded spinal cord injury model. Rubrospinal MEPs were recorded at T13 epidurally to monitor spinal cord function in end week 4 after graded spinal cord injury. The efficacy of this techniques to monitor spinal cord function was compared to BBB locomotor rating scale and histologic evaluation.

RESULTSA characteristic peak complex of rubrospinal MEPs in sham-operated group consisted of 5-7 positive waves and 4-5 negative waves emerging after red nucleus stimulation. The summed peak to peak amplitude (for practical reasons, called peak amplitude) was (195.25 +/- 34.35) microV and decreased following spinal cord injury. The latency of the first peak (positive wave) was (1.57 +/- 0.15) ms and prolonged following spinal cord injury. Significant Linear relationship existed between the peak amplitude and the BBB scores (r = 0.79) and between the peak amplitude and the residual matter obtained from the section with maximum tissue damage( r = 0.87). The close relationship between the latency of the first peak and the BBB scores (r = -0.88) and between the latency of the first peak and residual matter (r = -0.86) were observed.

CONCLUSIONAmplitudes and latencies of rubrospinal MEPs are very valuable parameters to demonstrate small function differences. Rubrospinal MEPs can be used as a reliable measure for motor function prognosis after spinal cord injury.

Animals ; Evoked Potentials, Motor ; Male ; Rats ; Rats, Wistar ; Red Nucleus ; physiopathology ; Spinal Cord Injuries ; pathology ; physiopathology

PURPOSE: Metabolic encephalopathy is not an infrequent condition. However it is very difficult to diagnose and treat because of its various causes and clinical manifestations. Our purpose was to clarify the cause of metabolic encephalopathy by evaluation of MR findings and clinical features. METHODS: We reviewed MR images and clinical features for 25 patients with metabolic encephalopathy who showed abnormal signal changes on the MR images with neurologic deterioration. RESULTS: The 25 patients had underlying diseases such as chronic liver disease (n=16) or renal failure (n=9). The MR findings showed significant differences in the involved sites according to the underlying disease. In 10 of the 16 patients with liver disease, corpus callosal involvement was observed. Red nucleus involvement was seen in 6 patients, dentate nucleus involvement in 5 patients. These lesions were seen to have a high signal intensity on the diffusion weighted image. Contrary to liver disease, encephalopathy with renal disease showed typical central pontine myelinolysis in 6 of the 9 patients and a relatively benign clinical course. CONCLUSION: Our results showed that the typically involved site and clinical manifestations depended on the underlying disease. We think that involvement of the corpus callosum, the red nucleus, and the dentate nucleus is a typical pattern of injury in metabolic encephalopathy with chronic liver disease and that these findings will be helpful for diagnosing and treating metabolic encephalopathy.
Brain Diseases, Metabolic* ; Cerebellar Nuclei ; Corpus Callosum ; Diffusion ; Humans ; Liver Diseases ; Myelinolysis, Central Pontine ; Red Nucleus ; Renal Insufficiency

Methyl bromide is presently used as a fumigant for insects in soil, grains or fruit in storage or transport. It is a neurotoxic agent and has been responsible a number of deaths or acute poisonings among occupationally exposed persons. We report 2 patients, who had worked fumigation warehouse, presented with seizures and altered mental state. The serum concentrations of bromide were elevated 32.9 and 42.5 mg/l, respectively. Brain MRI showed bilateral symmetric high signal intensities in the splenium of corpus callosum, the globus pallidus, the quadrigeminal plate, the periaqueductal gray matter, the red nucleus, the substantia nigra, the medial lemniscus, the pontine tegmentum, the dentate nucleus, and the medulla. There was no brain lesion in the other patient. Appropriate and supervised handling of the chemical and regular education to workers are important to avoid the risk of methyl bromide poisoning.
Brain ; Edible Grain ; Cerebellar Nuclei ; Corpus Callosum ; Education ; Fruit ; Fumigation ; Globus Pallidus ; Humans ; Insects ; Magnetic Resonance Imaging ; Occupations ; Periaqueductal Gray ; Poisoning ; Red Nucleus ; Seizures* ; Soil ; Substantia Nigra ; Tectum Mesencephali

Animals ; Electric Stimulation ; Neurons ; pathology ; physiology ; Pain Threshold ; Rats ; Rats, Sprague-Dawley ; Red Nucleus ; pathology ; physiology