Abordaje interhemisférico contralateral. Nota técnica / Contralateral interhemispheric approach. Technical note

El abordaje interhemisférico contralateral es una variante del abordaje interhemisférico transcalloso que permite optimizar el acceso a lesiones ubicadas en los ventrículos laterales o en sus paredes. La planificación del ángulo de entrada mediante neuronavegador nos permitió el manejo de un Cavernoma ubicado sobre el núcleo caudado e inmediato a la cápsula interna sin realizar callosotomía convencional ni comprometer las estructuras sensibles adyacentes.

Contralateral interhemispheric approach is a variant of the well-know interhemispheric transcallosal approach that allows to optimize the lateral wall ventricle lesions management. Neuronavigation planning allowed us to deal with a caudate nucleus cavernoma contiguous to internal capsule without conventional callosotomy and additional damage neither.

An Autopsy Proven Case of CSF1R-mutant Adult-onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia (ALSP) with Premature Ovarian Failure

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is a progressive degenerative white matter disorder caused by mutations in the tyrosine kinase domain of the CSF1R gene. ALSP is often misdiagnosed as other diseases due to its rarity and various clinical presentations such as Parkinsonism, pyramidal signs, cognitive impairment and/or psychiatric symptoms. We describe an autopsy case of ALSP with a CSF1R mutation. A 61-year-old woman presented insidious-onset gait difficulty for 12 years since her age of 49, and premature ovarian failure since her age of 35. At initial hospital visit, brain magnetic resonance imaging revealed hydrocephalus. Initially, Parkinson's syndrome was diagnosed, and she was prescribed L-dopa/carbidopa because of spasticity and rigidity of extremities, which had worsened. Subsequently, severe neuropsychiatric symptoms and cognitive impairment developed and radiologically, features of leukoencephalopathy or leukodystrophy were detected. She showed a down-hill course and died, 12 years after initial diagnosis. At autopsy, the brain showed severe symmetric atrophy of bilateral white matter, paper-thin corpus callosum, thin internal capsule, and marked hydrocephalus. Microscopically, diffuse loss of white matter, relatively preserved subcortical U-fibers, and many eosinophilic bulbous neuroaxonal spheroids were noted, but there was no calcification. Pigmented glia with brown cytoplasmic pigmentation were readily found in the white matter, which were positive for Periodic acid-Schiff, p62, and CD163 stains, but almost negative for CD68. Whole-exome and Sanger sequencing revealed a CSF1R mutation (c.2539G>A, p.Glu847Lys) which was reported in prior one ALSP case. This example demonstrates that ALSP could be associated with premature ovarian failure.

Three-axis Modification of Coordinates Enables Accurate Stereotactic Targeting in Non-human Primate Brains of Different Sizes

The brain grows with age in non-human primates (NHPs). Therefore, atlas-based stereotactic coordinates cannot be used directly to target subcortical structures if the size of the animal's brain differs from that used in the stereotactic atlas. Furthermore, growth is non-uniform across different cortical regions, making it difficult to simply apply a single brain-expansion ratio. We determined the skull reference lines that best reflect changes in brain size along the X, Y, and Z axes and plotted the changes in reference-line length against the changes in body weight. The skull reference lines had a linear relationship with body weight. However, comparison of skull reference lines with body weight confirmed the non-uniform skull growth during postnatal development, with skull growth more prominent in the X and Y axes than the Z axis. Comparing the differences between the atlas-based lengths and those calculated empirically from plot-based linear fits, we created craniometric indices that can be used to modify stereotactic coordinates along all axes. We verified the accuracy of the corrected stereotactic targeting by infusing dye into internal capsule in euthanized and preserved NHP brains. Our axis-specific, craniometric-index-adjusted stereotactic targeting enabled us to correct for targeting errors arising from differences in brain size. Histological verification showed that the method was accurate to within 1 mm. Craniometric index-adjusted targeting is a simple and relatively accurate method that can be used for NHP stereotactic surgery in the general laboratory, without the need for high-resolution imaging.

Utility of white matter to gray matter signal intensity ratio in comatose patients treated by targeted temperature management after cardiac arrest: a preliminary study

OBJECTIVE: This study examined the efficacy of the white matter (WM) to gray matter (GM) signal intensity ratio (SIR) in predicting the clinical prognosis of cardiac arrest patients. METHODS: Thirty-one patients who were resuscitated from cardiac arrest and underwent brain magnetic resonance imaging (MRI) were investigated retrospectively. Thirty one subjects with normal brain MRI findings served as the controls. The signal intensities (SI) were measured on T2-weighted image (T2WI). The circular regions of measurement (2–10 mm²) were placed over the regions of interest, and the average signals in GM and WM were recorded in the caudate nucleus (CN), putamen, anterior limb of the internal capsule, corpus callosum (CC), and in the cortex and WM of the frontal lobe. Cerebral performance category (CPC) 1–2 were classified as a good prognosis, and CPC 3–5 were classified as a poor prognosis. RESULTS: Most combinations of the SIR of WM to GM and most SIs of GM, except the frontal cortex, were significantly different between the two groups. On the other hand, the SI of WM was insignificant between both groups. In receiver operating characteristic (ROC) curve analysis, the SIR of the CC to CN had an area under the ROC curve (AUROC) of 1.00 for a cut-off value of 1.59 (sensitivity, 100%; specificity, 100%), the SIR of the CC to putamen had also an AUROC of 1.00 for a cut-off value of 1.43 (sensitivity, 100%; specificity, 100%). CONCLUSION: The SIR of WM to GM measured on a T2WI is related to the neurological outcome after a cardiac arrest.

Association Between Duration of Dysphagia Recovery and Lesion Location on Magnetic Resonance Imaging in Patients With Middle Cerebral Artery Infarction

OBJECTIVE: To investigate association between lesion location on magnetic resonance imaging (MRI) performed after an infarction and the duration of dysphagia in middle cerebral artery (MCA) infarction. METHODS: A videofluoroscopic swallowing study was performed for 59 patients with dysphagia who were diagnosed as cerebral infarction of the MCA territory confirmed by brain MRI. Lesions were divided into 11 regions of interest: primary somatosensory cortex, primary motor cortex, supplementary motor cortex, anterior cingulate cortex, orbitofrontal cortex, parieto-occipital cortex, insular cortex, posterior limb of the internal capsule (PLIC), thalamus, basal ganglia (caudate nucleus), and basal ganglia (putamen). Recovery time was defined as the period from the first day of L-tube feeding to the day that rice porridge with thickening agent was prescribed. Recovery time and brain lesion patterns were compared and analyzed. RESULTS: The mean recovery time of all patients was 26.71±16.39 days. The mean recovery time was 36.65±15.83 days in patients with PLIC lesions and 32.6±17.27 days in patients with caudate nucleus lesions. Only these two groups showed longer recovery time than the average recovery time for all patients. One-way analysis of variance for recovery time showed significant differences between patients with and without lesions in PLIC and caudate (p<0.001). CONCLUSION: Injury to both PLIC and caudate nucleus is associated with longer recovery time from dysphagia.

Effects of virtual reality therapy on upper limb function after stroke and the role of neuroimaging as a predictor of a better response / Efeitos da terapia de realidade virtual na função do membro superior após AVC e o papel da neuroimagem como preditor de melhor resposta

ABSTRACT Background: Virtual reality therapy (VRT) is an interactive intervention that induces neuroplasticity. The aim was to evaluate the effects of VRT associated with conventional rehabilitation for an upper limb after stroke, and the neuroimaging predictors of a better response to VRT. Methods: Patients with stroke were selected, and clinical neurological, upper limb function, and quality of life were evaluated. Statistical analysis was performed using a linear model comparing pre- and post-VRT. Lesions were segmented in the post-stroke computed tomography. A voxel-based lesion-symptom mapping approach was used to investigate the relationship between the lesion and upper limb function. Results: Eighteen patients were studied (55.5 ± 13.9 years of age). Quality of life, functional independence, and dexterity of the upper limb showed improvement after VRT (p < 0.001). Neuroimaging analysis showed negative correlations between the internal capsule lesion and functional recovery. Conclusion: VRT showed benefits for patients with stroke, but when there was an internal capsule lesion, a worse response was observed.

RESUMO Introdução: A realidade virtual (RV) é uma intervenção interativa que induz a neuroplasticidade. O objetivo deste estudo foi avaliar os efeitos da RV associado à reabilitação convencional na função do membro superior após o AVC e as características preditores de neuroimagem de melhor resposta a esta terapia. Métodos: os pacientes com AVC foram selecionados, e as características neurológicas, a função do membro superior e a qualidade de vida foram avaliadas. A análise estatística foi realizada por meio de modelo linear geral comparando resultados pré e pós-intervenção. As lesões foram segmentadas na tomografia computadorizada após o AVC. A abordagem de mapeamento da lesão-sintoma baseada em voxel foi utilizada para avaliar a relação entre a lesão e a função do membro superior. Resultados: Foram estudados 18 pacientes (8 mulheres, 55,5 ± 13,9 anos). A qualidade de vida, independência funcional, características funcionais e destreza do membro superior apresentaram melhora após RV (p < 0,001). A análise de imagem mostrou correlações negativas principalmente entre a cápsula interna e a recuperação funcional do membro superior. Conclusão: A RV mostrou benefícios para pacientes com AVC, mas quando houve lesão da cápsula interna apresentaram pior resposta à terapia.

Bilateral Lesions in the Posterior Limb of Internal Capsule Attributed to Combination Therapy of Isoniazid and Rifampin

Transient isoniazid-induced brain lesions have rarely been reported. The lesions were in the dentate nucleus of cerebellum and thalamus. Meanwhile, the neurotoxicity of rifampin has not been reported evidently. We observed bilateral lesions in the internal capsule in a young woman after taking a combination of isoniazid and rifampin. She transiently suffered numbness in both hands, dysarthria, and left side motor weakness while taking the medication. Isoniazid may induce structural lesions in various brain areas including the internal capsule.

Toxic Optic Neuropathy Caused by Chlorfenapyr Poisoning

PURPOSE: To report a case of toxic optic neuropathy caused by chlorfenapyr ingestion accompanied by central nervous system involvement. CASE SUMMARY: A 44-year-old female visited our clinic complaining of reduced visual acuity in both eyes for 7 days. She had ingested a mouthful of chlorfenapyr for a suicide attempt 2 weeks prior to the visit. Gastric lavage was performed immediately after ingestion at the other hospital. Her best-corrected visual acuity was finger count 30 cm in the right eye and hand motion in the left eye. Both pupils were dilated by 5.0 mm and the response to light was sluggish in both eyes. A relative afferent pupillary defect was detected in her left eye. Funduscopy revealed optic disc swelling in both eyes. Magnetic resonance imaging of the brain showed a symmetric hyper-intense signal in the white matter tract including the internal capsule, corpus callosum, middle cerebellar peduncle, and brainstem. The patient was diagnosed with toxic optic neuropathy induced by chlorfenapyr ingestion, and underwent high-dose intravenous corticosteroid pulse therapy. Three days later, the best-corrected visual acuity was no light perception in both eyes. Three months later, optic atrophy was observed in both eyes. Optical coherence tomography revealed a reduction in the thicknesses of the retinal nerve fiber layer and ganglion cell and inner plexiform layer in the macular area. CONCLUSIONS: Ingestion of even a small amount of chlorfenapyr can cause severe optic nerve damage through the latent period, despite prompt lavage and high-dose steroid treatment.

Evaluation of Ataxia in Mild Ischemic Stroke Patients Using the Scale for the Assessment and Rating of Ataxia (SARA)

OBJECTIVE: To demonstrate the utility of Scale for the Assessment and Rating of Ataxia (SARA) for evaluation of posterior circulation-related features in patients with mild stroke. METHODS: Forty-five subjects, diagnosed with acute infarction in the cerebellum, basis pontis, thalamus, corona radiata, posterior limb of internal capsule, and their National Institutes of Health Stroke Scale (NIHSS) scores ≤5 were enrolled. SARA scores were graded by the cut-off value of severity in dependency of activities of daily living (ADL). SARA, Berg Balance Scale (BBS), Timed Up-and-Go (TUG), and Trunk Control Test (TCT) were correlated in regression analysis with the modified Rankin Scale (mRS) at discharge. Correlation between SARA and other tools was analyzed. Patients were divided based on mRS at admission (group A, mRS 0–2; group B, mRS 3–5). Scores between the two groups were compared. RESULTS: Among the subjects, 48.9% (22/45) scored above 5.5 on SARA, and even 11.1% (5/45) scored higher than 14.25, which is the cut-off value of ‘severe dependency’ in ADL. SARA showed significant value for prediction of mRS at discharge. SARA was correlated with BBS (r=-0.946, p < 0.001), TUG (r=-0.584, p < 0.001), and TCT (r=-0.799, p < 0.001). The SARA, BBS, TUG, and TCT scores between were lower in group B than in group A patients. SARA as well as BBS, TUG, and TCT reflect the functional severity of all patients. CONCLUSION: SARA is a complementary tool for evaluation of the severity of ataxia in mild stroke patients with features of posterior circulation.

Changes in Diffusion Metrics of the Red Nucleus in Chronic Stroke Patients With Severe Corticospinal Tract Injury: A Preliminary Study

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.

The Upper Ascending Reticular Activating System between Intralaminar Thalamic Nuclei and Cerebral Cortex in the Human Brain

PURPOSE: The ascending reticular activating system (ARAS) is responsible for regulation of consciousness. In this study, using diffusion tensor imaging (DTI), we attempted to reconstruct the thalamocortical projections between the intralaminar thalamic nuclei and the frontoparietal cortex in normal subjects. METHODS: DTI data were acquired in 24 healthy subjects and eight kinds of thalamocortical projections were reconstructed: the seed region of interest (ROI) - the intralaminar thalamic nuclei and the eight target ROIs - the medial prefrontal cortex, dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, orbitofrontal cortex, premotor cortex, primary motor cortex, primary somatosensory cortex, and posterior parietal cortex. RESULTS: The eight thalamocortical projections were reconstructed in each hemisphere and the pathways were visualized: projections to the prefrontal cortex ascended through the anterior limb and genu of the internal capsule and anterior corona radiata. Projections to the premotor cortex passed through the genu and posterior limb of the internal capsule and middle corona radiata; in contrast, projections to the primary motor cortex, primary somatosensory cortex, and posterior parietal cortex ascended through the posterior limb of the internal capsule. No significant difference in fractional anisotropy, mean diffusivity, and fiber volume of all reconstructed thalamocortical projections was observed between the right and left hemispheres (p>0.05). CONCLUSION: We reconstructed the thalamocortical projections between the intralaminar thalamic nuclei and the frontoparietal cortex in normal subjects. We believe that our findings would be useful to clinicians involved in the care of patients with impaired consciousness and for researchers in studies of the ARAS.

Neurodevelopmental Outcomes According to Brain Injury Patterns in Neonates with Postasphyxial Hypoxic Ischemic Encephalopathy

PURPOSE: To investigate the relationship between brain injury patterns on magnetic resonance imaging (MRI) and neurodevelopmental outcomes in neonates with postasphyxial hypoxic ischemic encephalopathy (HIE). METHODS: Clinical characteristics and brain MRI findings of 49 term neonates with postasphyxial HIE were retrospectively reviewed. Brain injury patterns in MRI were classified into five categories, along with evaluation of the posterior limb of internal capsule (PLIC). Neurodevelopmental outcomes were assessed by neurological examination combined with the Bayley Scales of Infant Development II between 1 and 2 years of age. RESULTS: Twenty-three neonates (46.9%) showed abnormal brain MRI finding associated with poor neurodevelopmental outcomes (odds ratio 9.7, 95% confidence interval 1.4, 67.4, P=0.022). The following injury patterns were seen in MRI: abnormality in the basal ganglia-thalamus (BGT) in 4 neonates (17.4%), watershed predominant (WP) pattern in 5 (21.7%), extensive global injury (EGI) in 3 (13.0%), lesions restricted to periventricular white matter (LPWM) in 4 (17.4%), and perinatal arterial ischemic stroke (PAIS) in 2 (8.7%). Additionally, 6 neonate (26.1%) showed lesion in the PLIC. Neonate with BGT and EGI injury patterns showed worse neurodevelopmental outcomes than those with WP and LPWM patterns (P<0.05). Neonate with PLIC lesion also showed poor outcomes (100%). CONCLUSION: Abnormal brain MRI findings in neonates with postasphyxial HIE were associated with the poor neurodevelopmental outcomes. BGT, EGI and PLIC patterns of injury are expected to have worse outcomes than white matter predominant injury patterns such as those in the WP and LPWM.

An Experimental Infarct Targeting the Internal Capsule: Histopathological and Ultrastructural Changes

BACKGROUND: Stroke involving the cerebral white matter (WM) has increased in prevalence, but most experimental studies have focused on ischemic injury of the gray matter. This study was performed to investigate the WM in a unique rat model of photothrombotic infarct targeting the posterior limb of internal capsule (PLIC), focusing on the identification of the most vulnerable structure in WM by ischemic injury, subsequent glial reaction to the injury, and the fundamental histopathologic feature causing different neurologic outcomes. METHODS: Light microscopy with immunohistochemical stains and electron microscopic examinations of the lesion were performed between 3 hours and 21 days post-ischemic injury. RESULTS: Initial pathological change develops in myelinated axon, concomitantly with reactive change of astrocytes. The first pathology to present is nodular loosening to separate the myelin sheath with axonal wrinkling. Subsequent pathologies include rupture of the myelin sheath with extrusion of axonal organelles, progressive necrosis, oligodendrocyte degeneration and death, and reactive gliosis. Increase of glial fibrillary acidic protein (GFAP) immunoreactivity is an early event in the ischemic lesion. WM pathologies result in motor dysfunction. Motor function recovery after the infarct was correlated to the extent of PLIC injury proper rather than the infarct volume. CONCLUSIONS: Pathologic changes indicate that the cerebral WM, independent of cortical neurons, is highly vulnerable to the effects of focal ischemia, among which myelin sheath is first damaged. Early increase of GFAP immunoreactivity indicates that astrocyte response initially begins with myelinated axonal injury, and supports the biologic role related to WM injury or plasticity. The reaction of astrocytes in the experimental model might be important for the study of pathogenesis and treatment of the WM stroke.

White Matter Change Revealed by Diffusion Tensor Imaging in Gliomas

BACKGROUND: Tumor-related white matter change is detected at late stages with magnetic resonance imaging (MRI), when mass effect or prominent edema is present. We analyzed if diffusion tensor imaging (DTI) white matter change earlier than conventional MRI. METHODS: Twenty-six patients with gliomas (World Health Organization grade II, 5; grade III, 12; and grade IV, 9) within 2 cm from the posterior limb of the internal capsule (IC) were studied. Fifteen normal adults were enrolled as controls. Fluid attenuation inversion recovery MRI showed a high signal change at the posterior limb of the IC (HSIC) in 9 patients with grade III or IV gliomas. We classified the gliomas as WHO grade II (gliomas II), grade III or IV without HSIC [gliomas III/IV(-)] and grade III or IV with HSIC [gliomas III/IV(+)], as an indicator of the increase in the severity of the white matter changes. Fractional anisotropy (FA) and apparent diffusion coefficients (ADC) were calculated for the pyramidal tract. Tumor progression along pyramidal tract was evaluated by follow-up MRI in 16 patients at 40±18 months. RESULTS: FA showed no significant difference between gliomas II and control (p=0.694), but was lower in gliomas III/IV(-) and gliomas III/IV(+) (p<0.001). ADCs were higher in gliomas II, gliomas III/IV(-) and gliomas III/IV(+) than control (p<0.001). Tumor progression was detected in 2/16 patients. CONCLUSION: DTI detected white matter changes that appeared to be normal in MRI. ADC changed even in low grade glioma, indicating ADC may be a better parameter for the early detection of white matter change.

Prominent Cognitive Dysfunction without Motor Impairment Following Anterior Choroidal Artery Infarction: a Case Report

Neurological deficits commonly associated with anterior choroidal artery infarction (AChAI) include hemiplegia, hemisensory loss, and homonymous hemianopsia, while neuropsychological and perceptual deficits are uncommon. Prominent cognitive function impairment has rarely been reported. Here, we report a case of AChAI with prominent cognitive function impairment without motor deterioration. In contrast to the typical clinical features of AChAI, near complete and rapid motor recovery was observed, while cognitive impairment persisted despite rehabilitation therapy.

Association of Dysphagia With Supratentorial Lesions in Patients With Middle Cerebral Artery Stroke

OBJECTIVE: To determine the supratentorial area associated with poststroke dysphagia, we assessed the diffusion tensor images (DTI) in subacute stroke patients with supratentorial lesions. METHODS: We included 31 patients with a first episode of infarction in the middle cerebral artery territory. Each subject underwent brain DTI as well as a videofluoroscopic swallowing study (VFSS) and patients divided were into the dysphagia and non-dysphagia groups. Clinical dysphagia scale (CDS) scores were compared between the two groups. The corticospinal tract volume (TV), fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated for 11 regions of interest in the supratentorial area—primary motor cortex, primary somatosensory cortex, supplementary motor cortex, anterior cingulate cortex, orbitofrontal cortex, parieto-occipital cortex, insular cortex, posterior limb of the internal capsule, thalamus, and basal ganglia (putamen and caudate nucleus). DTI parameters were compared between the two groups. RESULTS: Among the 31 subjects, 17 were diagnosed with dysphagia by VFSS. Mean TVs were similar across the two groups. Significant inter-group differences were observed in two DTI values: the FA value in the contra-lesional primary motor cortex and the ADC value in the bilateral posterior limbs of the internal capsule (all p<0.05). CONCLUSION: The FA value in the primary motor cortex on the contra-lesional side and the ADC value in the bilateral PLIC can be associated with dysphagia in middle cerebral artery stroke.

Internal Capsular Infarction Presented as Monoataxia

No abstract available.

Endovascular Treatment in Ruptured Middle Cerebral Artery Dissection Preservation of Arterial Continuity

Rupture of spontaneous dissecting aneurysms of the middle cerebral artery (MCA) is rare and its etiology remains obscure, although the risk of rebleeding is greater than with saccular aneurysms. Most reports concerning the treatment of a ruptured dissecting aneurysm of the anterior circulation involve surgical trapping or wrapping. Here, we report on a case of an MCA dissecting rupture treated with endovascular procedures. A 22-year-old female presented with sudden stuporous mental change following severe headache and left side hemiparesis. A computed tomography scan showed a diffuse subarachnoid hemorrhage and diffusion MR showed diffusion restriction at the right putamen and internal capsule. A 3-hour follow-up digital subtraction angiography (DSA) showed a dissecting aneurysm, which was not seen on an initial DSA. A stent assisted coil embolization was performed and double stents were applied to achieve flow diversion effects. A small remnant area of the dissecting aneurysm had disappeared at 60-day and was not observed on 12-month follow-up DSA.

Can Predict Late Encephalopathy by Diffusion Tensor Imaging in Acute Phase of Carbon Monoxide Poisoning?

PURPOSE: Approximately 30% of patients with acute carbon monoxide (CO) poisoning display chronic neurological symptoms due to late encephalopathy, 1/3 in delayed neuropsychiatric sequelae (DNS) and 2/3 in persistent neurological symptoms (PNS). This study was conducted in order to determine whether diffusion tensor imaging (DTI) can sensitively represent damage to the brain in the acute phase after CO poisoning. METHODS: This prospective study included 132 patients with CO poisoning from February 2013 to February 2014. The patients were classified according to three groups: patients with asymptomatics; patients with PNS; and patients with DNS. Mean fractional anisotrophy (FA) and apparent diffusion coefficient (ADC) of regions of interest (ROI) in the acute phase were compared between the DNS or PNS groups and the asymptomatic group. DNS was considered present when the patient had clinical symptoms and signs of DNS within six weeks after exposure to CO poisoning. RESULTS: Late encephalopathy occurred at a rate of 18.9% (12.1% in the DNS, 6.7% in the PNS). DTI cannot sensitively represent brain damage of the DNS groups in the acute phase after CO poisoning. But low FA values of high frontal subcortex and low ADC values of globus pallidus in the DNS group clearly differed from those in the asymptomatic group. The PNS group showed significantly low FA and ADC values in centrum semiovale, several subcortics, globus pallidus, corpus callosum, and internal capsule. No significant difference in ADC was observed between patient groups. CONCLUSION: In the acute phase of CO poisoning, FA or ADC values sensitively represented damage to white matter in the some subcortex. However it had limited value in predicting the DNS because of no significant reduction of FA value in the centrum semiovale in the acute phase. However low values of FA and ADC in diffuse lesions in deep white matter and subcortex is a powerful predictor of the PNS.

Prolonged Motor Weakness With Syringomyelia in Japanese Encephalitis: A Case Study

Japanese encephalitis (JE) shows characteristic brain lesions, including bilateral thalamus, midbrain, internal capsule, basal ganglia, and occasionally involves an anterior horn cell. We encountered a case of a 44-year-old man who initially presented with encephalitis, which was finally diagnosed as Japanese encephalomyelitis with syringomyelia. The patient showed severe motor weakness followed by delayed recovery of functional motor activities. Cervical magnetic resonance imaging showed syrinx formation at the C5 level suggesting myelitis, and abnormal electromyographic findings were noted. Clinicians should consider the possibility that the spinal cord may be involved; an example would be syringomyelia due to myelitis in a case of JE presenting with severe and prolonged motor weakness.