Ventral targeted anterior capsulotomy for treatment-resistant depression and obsessive-compulsive disorder: A treatment method with cases

BACKGROUND

Ablative surgery using bilateral anterior capsulotomy (BAC) is an option for treatment resistant depression (TRD) and obsessive-compulsive disorder (TROCD). The location and extent of the lesion within anterior limb of the internal capsule (ALIC) remains uncertain. Accumulating evidence has suggested that the lesion should be located ventrally while limiting the dorsal extent. Our center is now targeting specific fiber tracts within the lower half of the ALIC.

METHOD

Presurgical diffusion tensor Magnetic Resonance Imaging (MRI) was used to identify individual fibre tracts within the ventral aspect of the ALIC in the last two patients who underwent BAC at our center. One patient had TRD and the other had both TROCD and TRD. Radiofrequency-induced thermal lesions were created in the identified targets with lesion volumes between 20 and 229 mm3 (average 95 mm3).

FINDINGS

Both patients were responders with neither experiencing significant side effects including compromised executive functions.

LIMITATIONS

The generalizability of our findings is limited because the outcome is based on two subjects.

CONCLUSION

This work suggests that BAC can be individually tailored and more limited to the ventral aspect of the ALIC and is effective and safe for TRD and TROCD. Accumulating data also suggests that to be clinically effective the length of the capsulotomy should be about 10mm. BAC's use may increase with the growing utilization and mastery of magnetic resonance guided focused ultrasound.

Internal capsule microstructure mediates the relationship between childhood maltreatment and PTSD following adulthood trauma exposure

Childhood trauma is a known risk factor for trauma and stress-related disorders in adulthood. However, limited research has investigated the impact of childhood trauma on brain structure linked to later posttraumatic dysfunction. We investigated the effect of childhood trauma on white matter microstructure after recent trauma and its relationship with future posttraumatic dysfunction among trauma-exposed adult participants (n = 202) recruited from emergency departments as part of the AURORA Study. Participants completed self-report scales assessing prior childhood maltreatment within 2-weeks in addition to assessments of PTSD, depression, anxiety, and dissociation symptoms within 6-months of their traumatic event. Fractional anisotropy (FA) obtained from diffusion tensor imaging (DTI) collected at 2-weeks and 6-months was used to index white matter microstructure. Childhood maltreatment load predicted 6-month PTSD symptoms (b = 1.75, SE = 0.78, 95% CI = [0.20, 3.29]) and inversely varied with FA in the bilateral internal capsule (IC) at 2-weeks (p = 0.0294, FDR corrected) and 6-months (p = 0.0238, FDR corrected). We observed a significant indirect effect of childhood maltreatment load on 6-month PTSD symptoms through 2-week IC microstructure (b = 0.37, Boot SE = 0.18, 95% CI = [0.05, 0.76]) that fully mediated the effect of childhood maltreatment load on PCL-5 scores (b = 1.37, SE = 0.79, 95% CI = [-0.18, 2.93]). IC microstructure did not mediate relationships between childhood maltreatment and depressive, anxiety, or dissociative symptomatology. Our findings suggest a unique role for IC microstructure as a stable neural pathway between childhood trauma and future PTSD symptoms following recent trauma. Notably, our work did not support roles of white matter tracts previously found to vary with PTSD symptoms and childhood trauma exposure, including the cingulum bundle, uncinate fasciculus, and corpus callosum. Given the IC contains sensory fibers linked to perception and motor control, childhood maltreatment might impact the neural circuits that relay and process threat-related inputs and responses to trauma.

Dural Arteriovenous Fistulas Presenting as Symmetric Lesions in the Internal Capsule on Imaging Studies: A Case Report and Literature Review

BACKGROUND

Dural arteriovenous fistulas (DAVFs) leading to oedema, primarily in the internal capsule, are extremely rare and, to our knowledge, have never been reported. We reported a case of DAVFs with oedema in bilateral internal capsule oedema and reviewed the literature.

METHODS

The report describes a unique imaging presentation of cases of DAVFs as symmetric lesions, mainly in the bilateral internal capsule. It also reviews the literature for symmetric lesions in the internal capsule and central grey matter caused by DAVFs to further characterize this rare entity and differential diagnosis through imaging features.

RESULTS

In cases of symmetric oedema caused by DAVFs, the most common artery involved in arterial supply was the middle meningeal artery (13/24; 54%). The main vein involved in the drainage was the Galen vein (18/29; 62%). Most cases were treated with transarterial embolization (23/29; 79%), and the probability of effective treatment or complete cure is 100%. On imaging, the vasogenic oedema signal caused by DAVFs is a symmetrical lesion of the bilateral internal capsule, that is, DWI MRI shows a high signal in the unrestricted diffusion area on the apparent diffusion coefficient map.

CONCLUSIONS

MR has good diagnostic value in abnormal basal ganglia symmetric signals caused by DAVFs, and can quickly identify DAVFs early.

Spatial patterns of intrinsic brain activity in rats with capsular stroke

BACKGROUND

To explore the neural changes of brain activity in rats with circumscribed capsular infarcts to find a new therapeutic target for promoting the functional recovery.

METHODS

A total of 18 capsular infarct rats and 18 normal rats were conducted in this study. All animal use procedures were strictly in accordance with the guide for the care and use of laboratory animals. After establishing the photothrombotic capsular infarct model, the functional magnetic resonance imaging (fMRI) data were collected and analyzed.

RESULTS

The fMRI results indicated that the passive movement would induce strong activation in caudate, putamen, frontal association somatosensory cortex, thalamus dorsolateral, and thalamus midline dorsal in control group, and the passive movement would only induce limited activation mostly in somatosensory cortex, thalamus dorsolateral, and thalamus midline dorsal in capsular infarct models. Capsular infarct makes the cortical activity weaken in sensory-related cortex and subcortical nuclei, including capsular area and thalamus.

CONCLUSIONS

Such findings imply that the posterior limb of internal capsule (PLIC) is connected to these structures in function, interacts together with them, and, accordingly, the lesion of PLIC manifests the related symptoms.

Protocatechudehyde improves mitochondrial energy metabolism through the HIF1α/PDK1 signaling pathway to mitigate ischemic stroke-elicited internal capsule injury

ETHNOPHARMACOLOGICAL RELEVANCE

The internal capsule is vulnerable to ischemia, and mild ischemic stroke often results in lesion of the internal capsule, manifested as contralateral hemiplegia. Protocatechudehyde (PCA), a potential neuroprotective agent, has shown therapeutic effects in the study of a variety of nervous system diseases, including ischemic stroke.

AIM OF THE STUDY

The aim of this study was to evaluate the effects of PCA on cerebral ischemia reperfusion (CI/R)-elicited internal capsule injury and to elucidate the role of mitochondrial energy metabolism in the underlying mechanism of neuroprotective effects on ischemic stroke.

MATERIALS AND METHODS

A rat tMCAO model was established to investigate the therapeutic effects of intravenous PCA (20, 40, and 80 mg/kg, once per day, continued for 7 days) on CI/R-induced internal capsule injury and the regulation of PCA on molecules related to mitochondrial energy metabolism. In vitro, an OGD/R model of PC12 cells was established to further verify the therapeutic mechanism of PCA.

RESULTS

Results showed that PCA dose-dependently attenuated neurological deficit, reduced cerebral infarction, alleviated histopathological damage, and improved mitochondrial ultrastructure of the internal capsule after CI/R. Moreover, PCA reversed the upregulation of HIF1α, PDK1 and pPDHA1 expression induced by CI/R and significantly increased the content of acetyl-CoA, ATP, and the activity of ATP synthase. In vitro, PCA treatment promoted cell survival, inhibited apoptosis, attenuated the dissipation of mitochondrial membrane potential in OGD/R-treated PC12 cells, and these therapeutic effects were reversed by the combination of cobalt chloride (CoCl₂), a specific pharmacological inducer of HIF1a expression.

CONCLUSIONS

These results indicate that PCA exerts a protective effect against CI/R-induced internal capsule injury and improves mitochondrial energy metabolism in the internal capsule, and the mechanism is associated with the inhibition of HIF1α/PDK1 signaling pathway.

The prognosis of brain magnetic resonance imaging injury pattern for outcomes of hypothermia-treated infants

Magnetic resonance imaging (MRI) can be a tool that allows the observation of structural injury patterns after cooling. The aim of this study was to determine the early pattern of brain injury in the MRIs of infants with hypoxic ischemic encephalopathy (HIE) after cooling and to search for any clinical factors related to abnormal MRI findings.The study retrospectively recruited 118 infants who were treated with therapeutic hypothermia (TH) between 2013 and 2016.Forty-three patients had normal brain MRI, and 75 had abnormal brain MRI findings. The TH-treated infants with abnormal brain MRI readings showed significantly more clinical seizures and the use of additional antiepileptic drugs (AEDs) than the normal MRI group. As a long-term outcome, more lesions in the basal ganglia and thalamus, posterior limb of internal capsule, or severe white matter lesions were associated with abnormal neurodevelopmental outcomes at 18 to 24 months of age.A higher frequency of clinical seizures and AED use were related to abnormal brain injury on MRI. A significant risk for poor long-term outcomes was found in the abnormal brain MRI group.

A fixel-based analysis of micro- and macro-structural changes to white matter following adult traumatic brain injury

Diffusion tensor imaging is often used to assess white matter (WM) changes following traumatic brain injury (TBI), but is limited in voxels that contain multiple fibre tracts. Fixel-based analysis (FBA) addresses this limitation by using a novel method of analysing high angular resolution diffusion-weighted imaging (HARDI) data. FBA examines three aspects of each fibre tract within a voxel: tissue micro-structure (fibre density [FD]), tissue macro-structure (fibre-bundle cross section [FC]) and a combined measure of both (FD and fibre-bundle cross section [FDC]). This study used FBA to identify the location and extent of micro- and macro-structural changes in WM following TBI. A large TBI sample (Nmild = 133, Nmoderate-severe = 29) and control group (healthy and orthopaedic; N = 107) underwent magnetic resonance imaging with HARDI and completed reaction time tasks approximately 7 months after their injury (range: 98-338 days). The TBI group showed micro-structural differences (lower FD) in the corpus callosum and forceps minor, compared to controls. Subgroup analyses revealed that the mild TBI group did not differ from controls on any fixel metric, but the moderate to severe TBI group had significantly lower FD, FC and FDC in multiple WM tracts, including the corpus callosum, cerebral peduncle, internal and external capsule. The moderate to severe TBI group also had significantly slower reaction times than controls, but the mild TBI group did not. Reaction time was not related to fixel findings. Thus, the WM damage caused by moderate to severe TBI manifested as fewer axons and a reduction in the cross-sectional area of key WM tracts.

Neuroimaging auditory verbal hallucinations in schizophrenia patient and healthy populations

BACKGROUND

Auditory verbal hallucinations (AVH) are a cardinal feature of schizophrenia, but they can also appear in otherwise healthy individuals. Imaging studies implicate language networks in the generation of AVH; however, it remains unclear if alterations reflect biologic substrates of AVH, irrespective of diagnostic status, age, or illness-related factors. We applied multimodal imaging to identify AVH-specific pathology, evidenced by overlapping gray or white matter deficits between schizophrenia patients and healthy voice-hearers.

METHODS

Diffusion-weighted and T1-weighted magnetic resonance images were acquired in 35 schizophrenia patients with AVH (SCZ-AVH), 32 healthy voice-hearers (H-AVH), and 40 age- and sex-matched controls without AVH. White matter fractional anisotropy (FA) and gray matter thickness (GMT) were computed for each region comprising ICBM-DTI and Desikan-Killiany atlases, respectively. Regions were tested for significant alterations affecting both SCZ-AVH and H-AVH groups, relative to controls.

RESULTS

Compared with controls, the SCZ-AVH showed widespread FA and GMT reductions; but no significant differences emerged between H-AVH and control groups. While no overlapping pathology appeared in the overall study groups, younger (<40 years) H-AVH and SCZ-AVH subjects displayed overlapping FA deficits across four regions (p < 0.05): the genu and splenium of the corpus callosum, as well as the anterior limbs of the internal capsule. Analyzing these regions with free-water imaging ascribed overlapping FA abnormalities to tissue-specific anisotropy changes.

CONCLUSIONS

We identified white matter pathology associated with the presence of AVH, independent of diagnostic status. However, commonalities were constrained to younger and more homogenous groups, after reducing pathologic variance associated with advancing age and chronicity effects.

Tractographic description of major subcortical projection pathways passing the anterior limb of the internal capsule. Corticopetal organization of networks relevant for psychiatric disorders

BACKGROUND

Major depression (MD) and obsessive-compulsive disorder (OCD) are psychiatric diseases with a huge impact on individual well-being. Despite optimal treatment regiments a subgroup of patients remains treatment resistant and stereotactic surgery (stereotactic lesion surgery, SLS or Deep Brain Stimulation, DBS) might be an option. Recent research has described four networks related to MD and OCD (affect, reward, cognitive control, default network) but only on a cortical and the adjacent sub-cortical level. Despite the enormous impact of comparative neuroanatomy, animal science and stereotactic approaches a holistic theory of subcortical and cortical network interactions is elusive. Because of the dominant hierarchical rank of the neocortex, corticofugal approaches have been used to identify connections in subcortical anatomy without anatomical priors and in part confusing results. We here propose a different corticopetal approach by identifying subcortical networks and search for neocortical convergences thereby following the principle of phylogenetic and ontogenetic network development.

MATERIAL AND METHODS

This work used a diffusion tensor imaging data from a normative cohort (Human Connectome Project, HCP; n = 200) to describe eight subcortical fiber projection pathways (PPs) from subthalamic nucleus (STN), substantia nigra (SNR), red nucleus (RN), ventral tegmental area (VTA), ventrolateral thalamus (VLT) and mediodorsal thalamus (MDT) in a normative space (MNI). Subcortical and cortical convergences were described including an assignment of the specific pathways to MD/OCD-related networks. Volumes of activated tissue for different stereotactic stimulation sites and procedures were simulated to understand the role of the distinct networks, with respect to symptoms and treatment of OCD and MD.

RESULTS

The detailed course of eight subcortical PPs (stnPP, snrPP, rnPP, vlATR, vlATRc, mdATR, mdATRc, vtaPP/slMFB) were described together with their subcortical and cortical convergences. The anterior limb of the internal capsule can be subdivided with respect to network occurrences in ventral-dorsal and medio-lateral gradients. Simulation of stereotactic procedures for OCD and MD showed dominant involvement of mdATR/mdATRc (affect network) and vtaPP/slMFB (reward network).

DISCUSSION

Corticofugal search strategies for the evaluation of stereotactic approaches without anatomical priors often lead to confusing results which do not allow for a clear assignment of a procedure to an involved network. According to our simulation of stereotactic procedures in the treatment of OCD and MD, most of the target regions directly involve the reward (and affect) networks, while side-effects can in part be explained with a co-modulation of the control network.

CONCLUSION

The here proposed corticopetal approach of a hierarchical description of 8 subcortical PPs with subcortical and cortical convergences represents a new systematics of networks found in all different evolutionary and distinct parts of the human brain.

Posterior limb of the internal capsule predicts poor quality of life in patients with Parkinson's disease: connectometry approach

Psychiatric symptoms and motor impairment are major contributions to the poor quality of life in patients with Parkinson's disease (PD). Here, we applied a novel diffusion-weighted imaging approach, diffusion MRI connectometry, to investigate the correlation of quality of life, evaluated by Parkinson's Disease Questionnaire (PDQ39) with the white matter structural connectivity in 27 non-demented PD patients (disease duration of 5.3 ± 2.9 years, H and Y stage = 1.5 ± 0.6, UPDRS-III = 13.7 ± 6.5, indicating unilateral and mild motor involvement). The connectometry analysis demonstrated bilateral posterior limbs of the internal capsule (PLIC) with increased connectivity related to the higher quality of life (FDR = 0.027) in a multiple regression model. The present study suggests for the first time a neural basis of the quality of life in PD in the light of major determinants of poor quality of life in these patients: anxiety, depression, apathy and motor impairment. Results in our sample of non-demented PD patients with relatively mild motor impairment and no apparent sign of depression/anxiety also identify a unique and inexplicable association of the PLIC to the quality of life in PD patients.

Which brain lesions produce spasticity? An observational study on 45 stroke patients

Spasticity is an important barrier that can hinder the restoration of function in stroke patients. Although several studies have attempted to elucidate the relationship between brain lesions and spasticity, the effects of specific brain lesions on the development of spasticity remain unclear. Thus, the present study investigated the effects of stroke lesions on spasticity in stroke patients. The present retrospective longitudinal observational study assessed 45 stroke patients using the modified Ashworth Scale to measure muscle spasticity. Each patient was assessed four times: initially (within 2 weeks of stroke) and at 1, 3, and 6 months after the onset of stroke. Brain lesions were analyzed using voxel-based lesion symptom mapping (VLSM) with magnetic resonance imaging images. Spasticity developed to a certain degree within 3 months in most stroke patients with spasticity. The VLSM method with non-parametric mapping revealed that lesions in the superior corona radiata, posterior limb of the internal capsule, posterior corona radiata, thalamus, putamen, premotor cortex, and insula were associated with the development of upper-limb spasticity. Additionally, lesions of the superior corona radiata, posterior limb of the internal capsule, caudate nucleus, posterior corona radiata, thalamus, putamen, and external capsule were associated with the development of lower-limb spasticity. The present study identified several brain lesions that contributed to post-stroke spasticity. Specifically, the involvement of white matter tracts and the striatum influenced the development of spasticity in the upper and lower limbs of stroke patients. These results may be useful for planning rehabilitation strategies and for understanding the pathophysiology of spasticity in stroke patients.

Gamma Ventral Capsulotomy in Intractable Obsessive-Compulsive Disorder

BACKGROUND

Despite the development of effective pharmacologic and cognitive behavioral treatments for obsessive-compulsive disorder (OCD), some patients continue to be treatment-refractory and severely impaired. Fiber tracts connecting orbitofrontal and dorsal anterior cingulate cortex with subcortical nuclei have been the target of neurosurgical lesions as well as deep brain stimulation in these patients. We report on the safety and efficacy of ventral gamma capsulotomy for patients with intractable OCD.

METHODS

Fifty-five patients with severely disabling, treatment-refractory OCD received bilateral lesions in the ventral portion of the anterior limb of the internal capsule over a 20-year period using the Leksell Gamma Knife. The patients were prospectively followed over 3 years with psychiatric, neurologic, and neuropsychological assessments of safety and efficacy, as well as structural neuroimaging.

RESULTS

Thirty-one of 55 patients (56%) had an improvement in the primary efficacy measure, the Yale-Brown Obsessive Compulsive Scale, of ≥35% over the 3-year follow-up period. Patients had significant improvements in depression, anxiety, quality of life, and global functioning. Patients tolerated the procedure well without significant acute adverse events. Five patients (9%) developed transient edema that required short courses of dexamethasone. Three patients (5%) developed cysts at long-term follow-up, 1 of whom developed radionecrosis resulting in an ongoing minimally conscious state.

CONCLUSIONS

Gamma Knife ventral capsulotomy is an effective radiosurgical procedure for many treatment-refractory OCD patients. A minority of patients developed cysts at long-term follow-up, 1 of whom had permanent neurological sequelae.

Can we predict development of impulsive-compulsive behaviours in Parkinson's disease?

OBJECTIVE

To determine clinical and structural imaging predictors of impulsive-compulsive behaviour (ICB) in de novo Parkinson's disease (PD).

METHODS

From a cohort of 1116 subjects from the Parkinson's Progression Marker Initiative database, we created a subcohort of 42 de novo PD without ICB at baseline with available 3T MRI and who developed ICB during follow-up. PD-ICB were matched for age, gender and disease duration to 42 patients with PD without ICB over follow-up (PD-no-ICB) and 42 healthy controls (HCs). Baseline demographic and clinical predictors of ICB were analysed. For the longitudinal neuroimaging analysis, we selected 27 patients with PD-ICB with available neuroimaging after ICB onset, who were matched with 32 PD-no-ICB and 35 HCs. Baseline and longitudinal structural differences were compared using voxel-based morphometry and voxel-based quantification.

RESULTS

People who went on to develop ICB had more severe anxiety, worse autonomic and global cognitive functions and were more likely to have rapid eye movement sleep behaviour disorder. Logistic regression confirmed that worse autonomic and cognitive functions were predictors of ICB. We could not find any morphological feature on baseline MRI that predicted later onset of ICB. When comparing PD groups at follow-up, a small region of increased atrophy in the anterior limb of the left internal capsule adjacent to the head of the left caudate nucleus was found in PD-ICB, but not surviving correction for multiple comparisons.

CONCLUSIONS

Worse autonomic and cognitive functions predict development of ICB at the time of PD diagnosis. Structural imaging fails to identify morphological features associated with the development of ICB.

Reduced white matter connectivity associated with auditory verbal hallucinations in first-episode and chronic schizophrenia: A diffusion tensor imaging study

This study aims to explore whether auditory verbal hallucinations (AVH) in schizophrenia are associated with the white matter abnormalities in tracts connecting language, auditory and memory/limbic networks in first-episode and chronic schizophrenia patients. 21 first-episode (FE-AVH) and 12 chronic (chronic-AVH group) patients who suffered from auditory verbal hallucinations and 26 healthy controls (HC group) were enrolled. Diffusion tensor imaging with tract-based spatial statistics was performed to assess the white matter changes between the two patient groups and HC group. Decreased fractional anisotropy and increased radial diffusivity were found in the patient groups compared to the HC group in multiple white matter tracts including the corpus callosum, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, cingulum, external capsule and anterior limb of the internal capsule. The chronic-AVH group showed more widespread white matter impairment than the FE-AVH group. Furthermore, increased axial diffusivity was also observed in some discrete regions of the chronic-AVH group. Auditory verbal hallucinations in schizophrenia are accompanied by white matter abnormalities in tracts connecting the language, auditory and memory/limbic networks. Chronic-AVH schizophrenia patients may present with more severe neurodegeneration relative to first-episode patients.

Ataxic Hemiparesis Associated with Cortical Infarct Localized in the Postcentral Gyrus

Ataxic hemiparesis (AH) is a classic lacunar syndrome associated with localized damage to the pons, internal capsule, thalamus, or corona radiata. A depression of metabolic activity known as crossed cerebellar diaschisis (CCD) is frequently observed in the cerebellar hemisphere contralateral to the site of the lesion in patients with AH. Though small cortical or subcortical lesions may result in AH, such occurrences are rare. The current report details the case of a patient with AH resulting from acute infarction associated with localized lesions of the postcentral gyrus who presented without CCD.

Microstructural changes to the brain of mice after methamphetamine exposure as identified with diffusion tensor imaging

Methamphetamine (METH) is an addictive psychostimulant inducing neurotoxicity. Human magnetic resonance imaging and diffusion tensor imaging (DTI) of METH-dependent participants find various structural abnormities. Animal studies demonstrate immunohistochemical changes in multiple cellular pathways after METH exposure. Here, we characterized the long-term effects of METH on brain microstructure in mice exposed to an escalating METH binge regimen using in vivo DTI, a methodology directly translatable across species. Results revealed four patterns of differential fractional anisotropy (FA) and mean diffusivity (MD) response when comparing METH-exposed (n=14) to saline-treated mice (n=13). Compared to the saline group, METH-exposed mice demonstrated: 1) decreased FA with no change in MD [corpus callosum (posterior forceps), internal capsule (left), thalamus (medial aspects), midbrain], 2) increased MD with no change in FA [posterior isocortical regions, caudate-putamen, hypothalamus, cerebral peduncle, internal capsule (right)], 3) increased FA with decreased MD [frontal isocortex, corpus callosum (genu)], and 4) increased FA with no change or increased MD [hippocampi, amygdala, lateral thalamus]. MD was negatively associated with calbindin-1 in hippocampi and positively with dopamine transporter in caudate-putamen. These findings highlight distributed and differential METH effects within the brain suggesting several distinct mechanisms. Such mechanisms likely change brain tissue differentially dependent upon neural location.

Ipsilesional motor-evoked potential absence in pediatric hemiparesis impacts tracking accuracy of the less affected hand

This study analyzed the relationship between electrophysiological responses to transcranial magnetic stimulation (TMS), finger tracking accuracy, and volume of neural substrate in children with congenital hemiparesis. Nineteen participants demonstrating an ipsilesional motor-evoked potential (MEP) were compared with eleven participants showing an absent ipsilesional MEP response. Comparisons of finger tracking accuracy from the affected and less affected hands and ipsilesional/contralesional (I/C) volume ratio for the primary motor cortex (M1) and posterior limb of internal capsule (PLIC) were done using two-sample t-tests. Participants showing an ipsilesional MEP response demonstrated superior tracking performance from the less affected hand (p=0.016) and significantly higher I/C volume ratios for M1 (p=0.028) and PLIC (p=0.005) compared to participants without an ipsilesional MEP response. Group differences in finger tracking accuracy from the affected hand were not significant. These results highlight differentiating factors amongst children with congenital hemiparesis showing contrasting MEP responses: less affected hand performance and preserved M1 and PLIC volume. Along with MEP status, these factors pose important clinical implications in pediatric stroke rehabilitation. These findings may also reflect competitive developmental processes associated with the preservation of affected hand function at the expense of some function in the less affected hand.

Axial Diffusivity of the Corona Radiata at 24 Hours Post-Stroke: A New Biomarker for Motor and Global Outcome

Fractional anisotropy (FA) is an effective marker of motor outcome at the chronic stage of stroke yet proves to be less efficient at early time points. This study aims to determine which diffusion metric in which location is the best marker of long-term stroke outcome after thrombolysis with diffusion tensor imaging (DTI) at 24 hours post-stroke. Twenty-eight thrombolyzed patients underwent DTI at 24 hours post-stroke onset. Ipsilesional and contralesional FA, mean (MD), axial (AD), and radial (RD) diffusivities values were calculated in different Regions-of-Interest (ROIs): (1) the white matter underlying the precentral gyrus (M1), (2) the corona radiata (CoRad), (3) the posterior limb of the internal capsule (PLIC) and (4) the cerebral peduncles (CP). NIHSS scores were acquired at admission, day 1, and day 7; modified Rankin Scores (mRS) at 3 months. Significant decreases were found in FA, MD, and AD of the ipsilesional CoRad and M1. MD and AD were also significantly lower in the PLIC. The ratio of ipsi and contralesional AD of the CoRad (CoRad-rAD) was the strongest diffusion parameter correlated with motor NIHSS scores on day 7 and with the mRS at 3 months. A Receiver-Operator Curve analysis yielded a model for the CoRad-rAD to predict good outcome based on upper limb NIHSS motor scores and mRS with high specificity and sensitivity. FA values were not correlated with clinical outcome. In conclusion, axial diffusivity of the CoRad from clinical DTI at 24 hours post-stroke is the most appropriate diffusion metric for quantifying stroke damage to predict outcome, suggesting the importance of early axonal damage.

Brain white matter microstructure in deficit and non-deficit subtypes of schizophrenia

Dividing schizophrenia into its deficit (SZD) and nondeficit (SZND) subtypes may help to identify specific and more homogeneous pathophysiological characteristics. Our aim was to define a whole brain voxelwise map specifically characterizing white matter tracts of schizophrenia patients with and without the deficit syndrome. We compared microstructural diffusion-related parameters as measured by diffusion tensor imaging in 21 SZD patients, 21 SZND patients, and 21 healthy controls, age- and gender-matched. Results showed that fractional anisotropy was reduced in the right precentral area in SZND patients, and in the left corona radiata of the schizophrenia group as a whole. Axial diffusivity was reduced in the left postcentral area of SZD patients and in the left cerebellum of the whole schizophrenia group. Radial diffusivity was increased in the left forceps minor of SZD patients, in the left internal capsule of SZND patients, and in the right inferior fronto-occipital fasciculus in the whole schizophrenia group. Mean diffusivity was increased from healthy controls to SZD patients to SZND patients in the right occipital lobe. In conclusion, SZD patients are not simply at the extreme end of a severity continuum of white matter disruption. Rather, the SZD and SZND subtypes are associated with distinct and specific brain microstructural anomalies that are consistent with their peculiar psychopathological dimensions.

Reduced anterior internal capsule white matter integrity in primary insomnia

Chronic insomnia is one of the most prevalent central nervous system diseases, however, its neurobiology is poorly understood. Up to now, nothing is known about the integrity of white matter tracts in insomnia patients. In this study, diffusion tensor imaging (DTI) was used in a well-characterized sample of primary insomnia (PI) patients and good sleeper controls to fill this void. Voxelwise between-group comparisons of fractional anisotropy (FA) were performed in 24 PI patients (10 males; 14 females; 42.7 ± 14.5 years) and 35 healthy good sleepers (15 males; 20 females; 40.1 ± 9.1 years) with age and sex as covariates. PI patients showed reduced FA values within the right anterior internal capsule and a trend for reduced FA values in the left anterior internal capsule. The results suggest that insomnia is associated with a reduced integrity of white matter tracts in the anterior internal capsule indicating that disturbed fronto-subcortical connectivity may be a cause or consequence of the disorder.

Long-term hydrocephalus alters the cytoarchitecture of the adult subventricular zone

Hydrocephalus can develop secondarily to a disturbance in production, flow and/or absorption of cerebrospinal fluid. Experimental models of hydrocephalus, especially subacute and chronic hydrocephalus, are few and limited, and the effects of hydrocephalus on the subventricular zone are unclear. The aim of this study was to analyze the effects of long-term obstructive hydrocephalus on the subventricular zone, which is the neurogenic niche lining the lateral ventricles. We developed a new method to induce hydrocephalus by obstructing the aqueduct of Sylvius in the mouse brain, thus simulating aqueductal stenosis in humans. In 120-day-old rodents (n=18 per group), the degree of ventricular dilatation and cellular composition of the subventricular zone were studied by immunofluorescence and transmission electron microscopy. In adult patients (age>18years), the sizes of the subventricular zone, corpus callosum, and internal capsule were analyzed by magnetic resonance images obtained from patients with and without aqueductal stenosis (n=25 per group). Mice with 60-day hydrocephalus had a reduced number of Ki67+ and doublecortin+cells on immunofluorescence, as well as decreased number of neural progenitors and neuroblasts in the subventricular zone on electron microscopy analysis as compared to non-hydrocephalic mice. Remarkably, a number of extracellular matrix structures (fractones) contacting the ventricular lumen and blood vessels were also observed around the subventricular zone in mice with hydrocephalus. In humans, the widths of the subventricular zone, corpus callosum, and internal capsule in patients with aqueductal stenosis were significantly smaller than age and gender-matched patients without aqueductal stenosis. In summary, supratentorial hydrocephalus reduces the proliferation rate of neural progenitors and modifies the cytoarchitecture and extracellular matrix compounds of the subventricular zone. In humans, this similar process reduces the subventricular niche as well as the width of corpus callosum and internal capsule.

Chronic cocaine administration causes extensive white matter damage in brain: diffusion tensor imaging and immunohistochemistry studies

The effect of chronic cocaine exposure on multiple white matter structures in rodent brain was examined using diffusion tensor imaging (DTI), locomotor behavior, and end point histology. The animals received either cocaine at a dose of 100mg/kg (N=19), or saline (N=17) for 28 days through an implanted osmotic minipump. The animals underwent serial DTI scans, locomotor assessment, and end point histology for determining the expressions of myelin basic protein (MBP), neurofilament-heavy protein (NF-H), proteolipid protein (PLP), Nogo-A, aquaporin-4 (AQP-4), and growth associated protein-43 (GAP-43). Differences in the DTI measures were observed in the splenium (scc) and genu (gcc) of the corpus callosum (cc), fimbria (fi), and the internal capsule (ic). A significant increase in the activity in the fine motor movements and a significant decrease in the number of rearing events were observed in the cocaine-treated animals. Reduced MBP and Nogo-A and increased GAP-43 expressions were most consistently observed in these structures. A decrease in the NF-H expression was observed in fi and ic. The reduced expression of Nogo-A and the increased expression of GAP-43 may suggest destabilization of axonal connectivity and increased neurite growth with aberrant connections. Increased GAP-43 suggests drug-induced plasticity or a possible repair mechanism response. The findings indicated that multiple white matter tracts are affected following chronic cocaine exposure.

Reduced integrity of sensorimotor projections traversing the posterior limb of the internal capsule in children with congenital hemiparesis

There is reduced integrity of corticospinal projections that traverse the posterior limb of the internal capsule (PLIC) in children with unilateral cerebral palsy (CP). It remains unclear whether there are changes in integrity of other projections traversing the PLIC. Forty children with congenital hemiparesis and 15 typically developing children underwent structural and diffusion-weighted MRI. All children with congenital hemiparesis showed lesions to the periventricular white matter. Structural images were parcellated into 34 cortical regions per hemisphere and posterior limb of the internal capsule was identified. PLIC connections to each cortical region were extracted using probabilistic tractography. Differences between hemispheres for each cortical projection (asymmetry index (AI)) and tract microstructure (fractional anisotropy (FA), mean diffusivity (MD)) were assessed. The results showed that 17 children (42.5%) with congenital hemiparesis showed bilateral lesions on structural MRI. Projections to the primary motor cortex (precentral gyrus and paracentral lobule) showed greater asymmetry in unilateral CP group compared to typically developing children and indicate reduced projections on the hemisphere contralateral to the impaired limb (i.e., contralateral hemisphere). Reduced FA and increased MD were also observed for connections with the primary motor cortex, primary sensory cortex (postcentral gyrus) and precuneus on the contralateral hemisphere in children with congenital hemiparesis. Similar changes were observed between children with unilateral and bilateral lesions on structural MRI. Notably, microstructural changes were associated with deficits in both sensory and motor function. The findings further unravel the underlying neuroanatomical correlates of sensorimotor deficits in children with congenital hemiparesis.

Extramotor damage is associated with cognition in primary lateral sclerosis patients

Objectives

This is a cross-sectional study aimed at investigating cognitive performances in patients with primary lateral sclerosis (PLS) and using diffusion tensor (DT) magnetic resonance imaging (MRI) to determine the topographical distribution of microstructural white matter (WM) damage in patients with or without cognitive deficits.

Methods

DT MRI scans were obtained from 21 PLS patients and 35 age- and sex-matched healthy controls. All PLS patients underwent a comprehensive neuropsychological battery. Tract-based-spatial-statistics (TBSS) was used to perform a whole-brain voxel-wise analysis of fractional anisotropy (FA), axial, radial (radD) and mean diffusivity (MD).

Results

Ten PLS patients had abnormal scores in at least one neuropsychological test (PLS with cognitive deficits, PLS-cd). Compared with healthy controls and cognitively unimpaired PLS patients (PLS-cu), PLS-cd cases showed decreased FA and increased MD and radD in the corticospinal tract (CST), corpus callosum, brainstem, anterior limb of internal capsule, superior and inferior longitudinal fasciculi, fornix, thalamic radiations, and parietal lobes, bilaterally. Compared with healthy controls, PLS-cd patients showed further decreased FA and increased radD in the cerebellar WM, bilaterally. Compared with controls, PLS-cu patients showed decreased FA in the mid-body of corpus callosum. In PLS, executive and language test scores correlated with WM damage.

Conclusions

This is the first study evaluating the relationship between cognitive performance and WM tract damage in PLS patients. PLS can be associated with a multi-domain cognitive impairment. WM damage to interhemispheric, limbic and major associative WM tracts seem to be the structural correlate of cognitive abnormalities in these patients.

MRI-based analysis of intracerebral hemorrhage in mice reveals relationship between hematoma expansion and the severity of symptoms

Intracerebral hemorrhage (ICH) is featured by poor prognosis such as high mortality rate and severe neurological dysfunction. In humans, several valuables including hematoma volume and ventricular expansion of hemorrhage are known to correlate with the extent of mortality and neurological dysfunction. However, relationship between hematoma conditions and the severity of symptoms in animal ICH models has not been clarified. Here we addressed this issue by using 7-tesla magnetic resonance imaging (MRI) on collagenase-induced ICH model in mice. We found that the mortality rate and the performance in behavioral tests did not correlate well with the volume of hematoma. In contrast, when hemorrhage invaded the internal capsule, mice exhibited high mortality and showed poor sensorimotor performance. High mortality rate and poor performance in behavioral tests were also observed when hemorrhage invaded the lateral ventricle, although worsened symptoms associated with ventricular hemorrhage were apparent only during early phase of the disease. These results clearly indicate that invasion of the internal capsule or the lateral ventricle by hematoma is a critical determinant of poor prognosis in experimental ICH model in mice as well as in human ICH patients. MRI assessment may be a powerful tool to refine investigations of pathogenic mechanisms and evaluations of drug effects in animal models of ICH.

Diffusion tensor imaging properties and neurobehavioral outcomes in children with hydrocephalus

BACKGROUND AND PURPOSE

White matter structural alterations and the correlation with neuropsychological deficits in children with hydrocephalus have not been well investigated. In this prospective study, the objectives were the following: 1) to apply DTI to detect in vivo white matter alterations based on diffusion properties in children with acute hydrocephalus, 2) to quantify early neuropsychological deficits, and 3) to explore the correlation between potential neuropsychological deficits and abnormalities in functionally related white matter.

MATERIALS AND METHODS

A total of 44 children, 24 with hydrocephalus and 20 controls, were enrolled in the study. DTI indices, FA, MD, AD, and RD, were evaluated in the gCC, sCC, PLIC, and ALIC. The ABAS-II was used as a broad screener of development, including conceptual, social, practical, and motor skills. The correlation between the Motor Scale and DTI indices in the PLIC was analyzed.

RESULTS

DTI analyses showed that the gCC and sCC in children with hydrocephalus had lower FA and higher MD, driven by the increased RD with statistical significance (P < .05) or trend-level significance (P = .06). The PLIC and ALIC had significantly higher AD in children with hydrocephalus (P < .05). On the ABAS-II, parent ratings of general adaptive skills, conceptual skills, and motor skills were significantly lower in children with hydrocephalus (all at P < .05). The MD and RD values in the PLIC were found to have trend-level or significant correlation with the Motor Scale (P = .057, .041, respectively).

CONCLUSIONS

DTI reveals alterations in the white matter structure in children with hydrocephalus with preliminary findings suggesting correlation with clinical motor deficits.

Pseudoperipheral palsy due to infarction in the internal capsule

Pseudoperipheral palsy can be caused by cerebral cortical infarctions; however, it is rarely caused by lacunar infarctions, including those in the posterior limb of the internal capsule. Meanwhile, the somatotopic localization of the corticospinal tract in the posterior limb of the internal capsule remains unknown. We herein report the case of an 81-year-old Japanese woman who presented with a left hand drop. Brain magnetic resonance imaging revealed an acute infarction as the causative lesion at the inferior level of the anteromedial portion of the posterior limb of the right internal capsule. This case report indicates the topography of hand fibers in the internal capsule.

Anterior limb of the internal capsule in schizotypal personality disorder: fiber-tract counting, volume, and anisotropy

Mounting evidence suggests that white matter abnormalities and altered subcortical-cortical connectivity may be central to the pathology of schizophrenia (SZ). The anterior limb of the internal capsule (ALIC) is an important thalamo-frontal white-matter tract shown to have volume reductions in SZ and to a lesser degree in schizotypal personality disorder (SPD). While fractional anisotropy (FA) and connectivity abnormalities in the ALIC have been reported in SZ, they have not been examined in SPD. In the current study, magnetic resonance (MRI) and diffusion tensor imaging (DTI) were obtained in age- and sex-matched individuals with SPD (n=33) and healthy controls (HCs; n=38). The ALIC was traced bilaterally on five equally spaced dorsal-to-ventral axial slices from each participant's MRI scan and co-registered to DTI for the calculation of FA. Tractography was used to examine tracts between the ALIC and two key Brodmann areas (BAs; BA10, BA45) within the dorsolateral prefrontal cortex (DLPFC). Compared with HCs, the SPD participants exhibited (a) smaller relative volume at the mid-ventral ALIC slice level but not the other levels; (b) normal FA within the ALIC; (c) fewer relative number of tracts between the most-dorsal ALIC levels and BA10 but not BA45 and (d) fewer dorsal ALIC-DLPFC tracts were associated with greater symptom severity in SPD. In contrast to prior SZ studies that report lower FA, individuals with SPD show sparing. Our findings are consistent with a pattern of milder thalamo-frontal dysconnectivity in SPD than schizophrenia.

Population-based study of capsular warning syndrome and prognosis after early recurrent TIA

OBJECTIVE

Many guidelines recommend emergency assessment for patients with ≥2 TIAs within 7 days, perhaps in recognition of the capsular warning syndrome. However, it is unclear whether all patients with multiple TIAs are at high early risk of stroke and whether treatable underlying pathologies are more prevalent in this group.

METHODS

We studied clinical characteristics, Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, and risk of stroke in 1,000 consecutive patients with incident and recurrent TIAs in a prospective, population-based study (Oxford Vascular Study).

RESULTS

Of 1,000 patients with TIAs, 170 had a further TIA within 7 days (105 within 24 hours). Multiple TIAs were not associated with carotid stenosis or atrial fibrillation, and much of the 10.6 (95% confidence interval [CI] 6.5-15.9) risk of stroke during the 7 days after the first TIA was due to patients with small-vessel disease (SVD) etiology (10 of 24 vs 8 of 146, odds ratio [OR] = 12.3, 95% CI 3.7-41.9, p < 0.0001), particularly those with motor weakness (i.e., capsular warning syndrome) compared with hemisensory events (9 of 15 [60%], 95% CI 35.3-84.7 vs 1 of 9 [11.1%], 95% CI 0-31.7, p = 0.03). The 7-day risk of stroke after a recurrent TIA was similar to the risk after a single TIA in patients with non-SVD TIA (8 of 146 [5.5%] vs 76 of 830 [9.2%], OR = 0.58, 95% CI 0.25-1.3, p = 0.20). Of the 9 patients with stroke after a capsular warning syndrome, all had the recurrent TIA within 24 hours after the first TIA, and the subsequent stroke occurred within 72 hours of the second TIA in 8. The ABCD2 scores of all preceding TIAs were ≥4 in all 9 patients with capsular warning syndrome before stroke.

CONCLUSIONS

Capsular warning syndrome is rare (1.5% of TIA presentations) but has a poor prognosis (7-day stroke risk of 60%). Otherwise, recurrent TIA within 7 days is not associated with a greater stroke risk than that after a single TIA.

Both projection and commissural pathways are disrupted in individuals with chronic stroke: investigating microstructural white matter correlates of motor recovery

BACKGROUND

Complete recovery of motor function after stroke is rare with deficits persisting into the chronic phase of recovery. Diffusion tensor imaging (DTI) can evaluate relationships between white matter microstructure and motor function after stroke. The objective of this investigation was to characterize microstructural fiber integrity of motor and sensory regions of the corpus callosum (CC) and descending motor outputs of the posterior limb of the internal capsule (PLIC) in individuals with chronic stroke and evaluate the relationships between white matter integrity and motor function.

RESULTS

Standardized measures of upper extremity motor function were measured in thirteen individuals with chronic stroke. Manual dexterity was assessed in thirteen healthy age-matched control participants. DTI scans were completed for each participant. Fractional anisotropy (FA) of a cross-section of sensory and motor regions of the CC and the PLIC bilaterally were quantified. Multivariate analysis of variance evaluated differences between stroke and healthy groups. Correlational analyses were conducted for measures of motor function and FA. The stroke group exhibited reduced FA in the sensory (p = 0.001) region of the CC, contra- (p = 0.032) and ipsilesional (p = 0.001) PLIC, but not the motor region of the CC (p = 0.236). In the stroke group, significant correlations between contralesional PLIC FA and level of physical impairment (p = 0.005), grip strength (p = 0.006) and hand dexterity (p = 0.036) were observed.

CONCLUSIONS

Microstructural status of the sensory region of the CC is reduced in chronic stroke. Future work is needed to explore relationships between callosal sensorimotor fiber integrity and interhemispheric interactions post-stroke. In addition, contralesional primary motor output tract integrity is uniquely and closely associated with multiple dimensions of motor recovery in the chronic phase of stroke suggesting it may be an important biomarker of overall motor recovery.

The relationship between delirium duration, white matter integrity, and cognitive impairment in intensive care unit survivors as determined by diffusion tensor imaging: the VISIONS prospective cohort magnetic resonance imaging study*

OBJECTIVE

Evidence is emerging that delirium duration is a predictor of long-term cognitive impairment in intensive care unit survivors. Relationships between 1) delirium duration and brain white matter integrity, and 2) white matter integrity and long-term cognitive impairment are poorly understood and could be explored using magnetic resonance imaging.

DESIGN, SETTING, PATIENTS

A two-center, prospective cohort study incorporating delirium monitoring, neuroimaging, and cognitive testing in intensive care unit survivors.

MEASUREMENTS

Delirium was evaluated with the Confusion Assessment Method for the Intensive Care Unit and cognitive outcomes were tested at 3 and 12-month follow-up. Following the intensive care unit stay, fractional anisotropy, a measure of white matter integrity, was calculated quantitatively using diffusion tensor imaging with a 3-T magnetic resonance imaging scanner at hospital discharge and 3-month follow-up. We examined associations between 1) delirium duration and fractional anisotropy and 2) fractional anisotropy and cognitive outcomes using linear regression adjusted for age and sepsis.

RESULTS

A total of 47 patients with a median age of 50 yrs completed the diffusion tensor imaging-magnetic resonance imaging protocol. Greater duration of delirium (3 vs. 0 days) was associated with lower fractional anisotropy (i.e., reduced fractional anisotropy = white matter disruption) in the genu (-0.02; p = .04) and splenium (-0.01; p = .02) of the corpus callosum and anterior limb of the internal capsule (-0.02; p =.01) at hospital discharge. These associations persisted at 3 months for the genu (-0.02; p =.02) and splenium (-0.01; p = .004). Lower fractional anisotropy in the anterior limb of internal capsule at discharge and in genu of corpus callosum at three months was associated with worse cognitive scores at 3 and 12 months.

CONCLUSIONS

In this pilot investigation, delirium duration in the intensive care unit was associated with white matter disruption at both discharge and 3 months. Similarly, white matter disruption was associated with worse cognitive scores up to 12 months later. This hypothesis-generating investigation may help design future studies to explore these complex relationships in greater depth.

[Fractional anisotropy and somatosensory evoked potentials in the postcentral gyrus subcortex after acute infarction of the posterior limb of the internal capsule]

OBJECTIVE

To investigate the relationship between fractional anisotropy (FA) and somatosensory evoked potentials (SEP) in the postcentral gyrus subcortex in patients with acute infarction of the posterior limb of the internal capsule.

METHODS

Thirty-one patients with acute infarction of the posterior limb of the internal capsule underwent diffusion tensor imaging to obtain the FA values of the subcortical region of the postcentral gyrus with manual placement of the regions of interest (ROI). SEP and the sensory functions of the patients were examined and graded.

RESULTS

In each SEP grade group, the FA values of the subcortical region of the postcentral gyrus were significantly decreased on the diseased side compared to those of the normal side (P<0.05). The FA values of the diseased side differed significantly between patients with different SEP grades (P<0.05), and increased SEP abnormalities were associated with lowered FA values. The sensory function of the patients was positively correlated to the grade of SEP (r=0.520, P<0.05).

CONCLUSION

For patients with acute infarction of the posterior limb of the internal capsule, the changes of FA in the postcentral gyrus subcortex on the diseased side are correlated and complementary to SEP in evaluating the prognosis.

Fractional anisotropy and radial diffusivity: diffusion measures of white matter abnormalities in the anterior limb of the internal capsule in schizophrenia

INTRODUCTION

Higher cognitive functioning is mediated by frontal-subcortical cognitive and limbic feedback sub-loops. The thalamo-cortical projection through the anterior limb of the internal capsule (ALIC) serves as the final step in these feedback sub-loops. We evaluated abnormalities in the ALIC fiber tract in schizophrenia using both structural MRI and diffusion tensor imaging (DTI).

METHODS

20 chronic schizophrenia patients and 22 male, normal controls group matched for handedness, age, and parental SES, underwent structural and DTI brain imaging on a 1.5 Tesla GE system. We manually measured ALIC volume normalized for intracranial contents (ICC) using structural brain images and then registered these high resolution structural brain scan derived ALIC label maps to DTI space allowing for the measurement in the ALIC of diffusion indices including, fractional anisotropy (FA) mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD).

RESULTS

We found in the ALIC of chronic schizophrenia subjects, compared with normal controls, bilaterally lower FA and bilaterally higher RD, but no differences in AD, MD, or relative volume. Cognitive correlations in schizophrenia patients showed, in particular, that higher left ALIC FA correlated positively with better verbal and nonverbal declarative/episodic memory performance.

DISCUSSION

Using a novel approach to assess both diffusion and volume measures in the ALIC in schizophrenia, we found abnormalities in measures of diffusion, but not volume, supporting their importance as sensitive indices of abnormalities in white matter fiber bundles in schizophrenia. Our findings also support the role of ALIC white matter tract FA abnormalities in declarative/episodic memory in schizophrenia.

Glomuvenous Malformations (Familial generalized multiple glomangiomas)

A 15-year-old boy with a diagnosis of generalized multiple glomangiomas was referred for evaluation and treatment of enlarging and increasingly painful lesions on his right ankle. The patient underwent a series of two treatments with long-pulsed KTP 1064 nm laser that resulted in substantial improvement in appearance and decreased pain. Generalized glomuvenous malformations, or multiple glomangiomas, are the less common presentation of proliferation of glomus cells and may have extracutaneous involvement. Whereas surgical management is often employed and definitive for solitary lesions, interventions such as laser therapy, may be beneficial for improvement of functional impairment and cosmesis as was observed in our patient.

White matter integrity in individuals at high genetic risk of bipolar disorder

BACKGROUND

Bipolar disorder is a familial psychiatric disorder associated with reduced white matter integrity, but it is not clear whether such abnormalities are present in young unaffected relatives and, if so, whether they have behavioral correlates. We investigated with whole brain diffusion tensor imaging whether increased genetic risk for bipolar disorder is associated with reductions in white matter integrity and whether these reductions are associated with cyclothymic temperament.

METHODS

Diffusion tensor imaging data of 117 healthy unaffected relatives of patients with bipolar disorder and 79 control subjects were acquired. Cyclothymic temperament was measured with the cyclothymia scale of the Temperament Evaluation of Memphis, Pisa and San Diego auto-questionnaire. Voxel-wise between-group comparisons of fractional anisotropy (FA) and regression of cyclothymic temperament were performed with tract-based spatial statistics.

RESULTS

Compared to the control group, unaffected relatives had reduced FA in one large widespread cluster. Cyclothymic temperament was inversely related to FA in the internal capsules bilaterally and in left temporal white matter, regions also found to be reduced in high-risk subjects.

CONCLUSIONS

These results show that widespread white matter integrity reductions are present in unaffected relatives of bipolar patients and that more localized reductions might underpin cyclothymic temperament. These findings suggest that white matter integrity is an endophenotype for bipolar disorder with important behavioral associations previously linked to the etiology of the condition.

Contraversive shift of conjugate eye deviation in hemispheric stroke indicates emerging mass effect

Conjugate eye deviation (CED) towards the ipsilateral or the contralateral side of the brain lesion can occur as a result of acute hemispheric stroke. To our knowledge, there have been no reports of CED shifting from the lesional side to the contralateral side in acute hemispheric stroke in the literature. We present four patients with right hemispheric stroke with a forced CED shift from the right to the left side during the acute stage with corresponding mass effect on the right internal capsule and right thalamus, as shown on brain imaging. Mass effect on thalamic mediated circuits and the corticopontine projection within the internal capsule probably underlies this CED shift via the dynamic balance of oculomotor control between the two hemispheres. Contraversive CED shift is a potentially useful early predictor of emerging mass effect in acute hemispheric stroke.

Correlations between ventricular enlargement and gray and white matter volumes of cortex, thalamus, striatum, and internal capsule in schizophrenia

Ventricular enlargement is one of the most consistent abnormal structural brain findings in schizophrenia and has been used to infer brain shrinkage. However, whether ventricular enlargement is related to local overlying cortex and/or adjacent subcortical structures or whether it is related to brain volume change globally has not been assessed. We systematically assessed interrelations of ventricular volumes with gray and white matter volumes of 40 Brodmann areas (BAs), the thalamus and its medial dorsal nucleus and pulvinar, the internal capsule, caudate and putamen. We acquired structural MRI ( patients with schizophrenia (n = 64) and healthy controls (n = 56)) and diffusion tensor fractional anisotropy (FA) (untreated schizophrenia n = 19, controls n = 32). Volumes were assessed by manual tracing of central structures and a semi-automated parcellation of BAs. Patients with schizophrenia had increased ventricular size associated with decreased cortical gray matter volumes widely across the brain; a similar but less pronounced pattern was seen in normal controls; local correlations (e.g. temporal horn with temporal lobe volume) were not appreciably higher than non-local correlations (e.g. temporal horn with prefrontal volume). White matter regions adjacent to the ventricles similarly did not reveal strong regional relationships. FA and center of mass of the anterior limb of the internal capsule also appeared differentially influenced by ventricular volume but findings were similarly not regional. Taken together, these findings indicate that ventricular enlargement is globally interrelated with gray matter volume diminution but not directly correlated with volume loss in the immediately adjacent caudate, putamen, or internal capsule.

White matter compromise of callosal and subcortical fiber tracts in children with autism spectrum disorder: a diffusion tensor imaging study

OBJECTIVE

Autism spectrum disorder (ASD) is increasingly viewed as a disorder of functional networks, highlighting the importance of investigating white matter and interregional connectivity. We used diffusion tensor imaging (DTI) to examine white matter integrity for the whole brain and for corpus callosum, internal capsule, and middle cerebellar peduncle in children with ASD and typically developing (TD) children.

METHOD

DTI data were obtained from 26 children with ASD and 24 matched TD children. Fractional anisotropy (FA), mean diffusivity (MD), and axial and radial diffusion were calculated for the whole brain, the genu, body, and splenium of the corpus callosum, the genu and anterior and posterior limbs of the internal capsule, and the middle cerebellar peduncle.

RESULTS

Children with ASD had reduced FA and increased radial diffusion for whole-brain white matter and all three segments of the corpus callosum and internal capsule, compared with those in TD children. Increased MD was found for the whole brain and for anterior and posterior limbs of the internal capsule. Reduced axial diffusion was found for the body of corpus callosum. Reduced FA was also found for the middle cerebellar peduncle.

CONCLUSIONS

Our findings suggest widespread white matter compromise in children with ASD. Abnormalities in the corpus callosum indicate impaired interhemispheric transfer. Results for the internal capsule and middle cerebellar peduncle add to the currently limited DTI evidence on subcortico-cortical tracts in ASD. The robust impairment found in all three segments of the internal capsule is consistent with studies documenting impairment of elementary sensorimotor function in ASD.

Clinicopathologic features and outcomes of neuro-Behçet disease in Spain: a study of 20 patients

BACKGROUND

To describe the clinical characteristics and evolution of a series of adult patients hospitalized for neuro-Behçet disease (NBD).

METHODS

Consecutive patients admitted for NBD in a teaching hospital were retrospectively selected. Disability at discharge and during follow-up was graded with the modified Rankin Scale, and outcome classified as good or poor (grades 3-6).

RESULTS

Twenty patients were included (M/F, 13/7). Mean age at NBD diagnosis was 36.3 years. Nineteen patients had other manifestations of Behçet disease (BD) before NBD developed, but only 7 met the complete diagnostic criteria for BD. Fever, headache, motor weakness, and cranial nerve palsy were each present in approximately 60% of patients. There was a low prevalence of behavioral changes (5%), seizures (5%), and sphincter incontinence (0%), and a relatively high prevalence of meningism (25%). Non-neurologic manifestations of BD were concurrently detected in 15 patients (75%). 80% had parenchymal involvement. Brain biopsies during 5 attacks showed perivascular lymphocytic infiltration with reactive astrocytosis, but no frank vasculitis. During a mean follow-up of 6.3 years per patient, 12 had at least one relapse. In total, there were 22 relapses; all but two were in the same location and were symptomatically similar in each patient. At the end of follow-up, 7 patients (35%) had a poor outcome, including 4 who died.

CONCLUSION

Recording of previous manifestations of BD and a physical examination to detect concomitant systemic manifestations of BD may help establish an early diagnosis of NBD. Relapses frequently occurred in the same location. No frank vasculitis was present in brain biopsies.

Pseudoperipheral palsy due to cortical infarction

We present two cases of isolated hand weakness that were initially thought to be due to lower motor neurone lesions until subsequent MRI confirmed strokes in both. Small strokes are important to identify in order to optimise secondary prevention.

Predicting the motor outcome of acute disseminated encephalomyelitis by apparent diffusion coefficient imaging: Two case reports

We present two cases of young adults with acute disseminated encephalomyelitis (ADEM) who developed severe conscious and motor disturbances. Despite their similar initial clinical course and MRI findings, their motor function outcomes were quite different. In both cases, fluid attenuated inversion recovery (FLAIR) sequenced MRI showed multiple symmetric hyperintense lesions in the internal capsule and the brainstem at the subacute stage. However, in case 1 the apparent diffusion coefficient (ADC) was pathologically decreased in the internal capsule, whereas the ADC for case 2 was normal. At the end of the examination period, severe motor disability (bedridden state) with brain atrophy apparent on MRI remained in case 1, whereas case 2 made an almost full recovery without brain atrophy. These two cases suggest that altered ADC in the internal capsules at the subacute stage may reflect a different pathogenesis between cytotoxic and vasogenic edema, and may be a valuable indicator for the prognosis of motor disturbance.

A tractography analysis of two deep brain stimulation white matter targets for depression

BACKGROUND

Deep brain stimulation (DBS) of the subcallosal cingulate white matter (SCCwm) or anterior limb of the internal capsule (ALIC) may be effective in treating depression. Connectivity patterns of these regions may inform on mechanisms of action for DBS of these targets.

METHODS

Diffusion tensor imaging (DTI) and probabilistic tractography were performed in 13 nondepressed subjects to determine connectivity patterns of SCCwm and ALIC. Tract maps were generated for each target in each subject, and tract voxels were coded as being unique to either target or shared. Group level tract maps were generated by including only those voxels common to at least 10 of 13 (>75%) subjects.

RESULTS

The two targets have distinct patterns of connectivity with regions of overlap. The SCCwm showed consistent ipsilateral connections to the medial frontal cortex, the full extent of the anterior and posterior cingulate, medial temporal lobe, dorsal medial thalamus, hypothalamus, nucleus accumbens, and the dorsal brainstem. The ALIC seed, in contrast, demonstrated widespread projections to frontal pole, medial temporal lobe, cerebellum, nucleus accumbens, thalamus, hypothalamus, and brainstem. Common to both targets, albeit through distinct white matter bundles, were connections to frontal pole, medial temporal lobe, nucleus accumbens, dorsal thalamus, and hypothalamus.

CONCLUSIONS

Connectivity patterns of these two DBS white matter targets suggest distinct neural networks with areas of overlap in regions implicated in depression and antidepressant response.

Capsular warning syndrome: report of a case

The "capsular warning syndrome" (CWS) is characterized by recurrent stereotypical episodes of motor and/or sensory dysfunction without cortical signs. CWS is a clinically well recognized entity, and carries a significant risk of capsular infarct. The ischemia is most likely ascribable to hemodynamic changes in diseased small penetrating vessels. Treatment remains controversial and none has been proven effective. We described a 66-year-old man having 15 episodes of stereotypical transient ischemic attack within four days. The findings of the diffusion-weighted image showed abnormalities confined concurrently to the left lateral thalamus, posterior globus pallidus, and posterior corona radiata while the internal capsule was spared. Theses findings suggest involvement of the territory of anterior choroidal artery. We also documented changes in the pattern of attacks after initiation of intravenous urokinase.