Correlation of glioma proliferation assessed by flow cytometry with Tc-Tetrofosmin SPECT uptake

Objectives

Brain single-photon emission computed tomography (SPECT) has been proposed as a potentially useful modality for the metabolic assessment of various brain tumors.

Material and methods

In a 10-patient prospective pilot study we evaluated whether ^99mTc-Tetrofosmin (^99mTc-TF) uptake correlates with glioma proliferative activity assessed by flow cytometric analysis. ^99mTc-TF brain SPECT was performed shortly before surgical tumor excision.

Results

Eight patients were diagnosed with glioblastoma multiform and 2 with anaplastic astrocytoma. All tumors were aneuploid. We found a significant positive linear correlation between ^99mTc-TF uptake and percentage of tumor cells on the S-phase of the cell cycle (r = 0.92, P = 0.001).

Conclusion

Initial evidence suggests that ^99mTc-TF could provide a non-invasive indicator of glioma proliferative activity.     

A combined a-EEG and MR spectroscopy study in term newborns with hypoxic–ischemic encephalopathy

Objectives

Brain damage following a perinatal hypoxic–ischemic (HI) insult has been documented by different diagnostic techniques. The aim of the present study was to relate a-EEG time course during the first 24 h of life to brain metabolic changes detected by proton MR spectroscopy (¹H-MRS) at 7–10 days of life and to evaluate their correlation with outcome.

Methods

Thirty-two patients with any grade HI encephalopathy were studied. Thirty-one out of 32 patients survived and underwent ¹H-MRS examination at 7–10 days of life; a-EEG was recorded during the first 24 h of life in 27/32 newborns; 26 patients underwent both examinations. Griffiths test, evaluation of motor skills, visual and hearing function were performed at regular intervals until the age of 2 years.

Results

a-EEG at 6, 12 and 24 h of life showed a significant correlation with outcome. N-acetyl-aspartate/creatine (Cr), Lactate/Cr and myo-inositol differed significantly between patients with normal or poor outcome. a-EEG time course during the first 24 h of life showed improvement in newborns with normal ¹H-MRS and good outcome and a deterioration in those with abnormal ¹H-MRS and poor outcome.

Conclusions

a-EEG time course may be able to document the severity and the evolution of the cerebral damage following an HI event. a-EEG is related to the severity of cerebral injury as defined by ¹H-MRS and both examinations showed a good correlation with outcome. These data, obtained in non-cooled infants, may represent reference data for future investigations in cooled infants.     

Diagnostic impact of baseline cerebral blood flow in patients with acute ischemic stroke prior to intravenous recombinant tissue plasminogen activator therapy

Objective

To determine whether severe cerebral perfusion defects measured by SPECT prior to rt-PA therapy attribute to severe intracerebral hemorrhage (SICH).

Methods

We measured baseline cerebral blood flow (CBF) using technetium-99m-labeled hexamethylpropyleneamine oxime (99mTc-HMPAO) SPECT qualitatively prior to rt-PA therapy, in 52 consecutive patients (range 38–93 years). The degree and extent of the asymmetry of local CBF were analyzed semi-quantitatively. We did not administrate rt-PA in patients with severe perfusion defects. Clinical outcome and the incidence of SICH were studied.

Results

Three (5.8%) patients had severe perfusion defects that were undetected by CT and/or DWI. The other 49 (94.2%) patients had mild perfusion defects. The asymmetry of local CBF was 0.08 ± 0.08 (n = 3) and 0.3 ± 0.15 (n = 49) in the two groups, respectively. The percentages of the ipsilateral hemisphere in which perfusion was impaired severely were 17.5 ± 9.5% (n = 3) and 0.43 ± 0.87% (n = 49). Two patients were found petechial hemorrhage, but there was no patient who developed SICH in the former group following conventional antithrombotic therapy. In the latter group, SICH occurred in 1/49 (2.0%) patient following rt-PA therapy.

Conclusion

These results suggest that rt-PA therapy for patients with severe cerebral perfusion defects may cause SICH and baseline CBF may contribute to identify patients at high risk for SICH after intravenous rt-PA therapy.     

Equivalent brain SPECT perfusion changes underlying therapeutic efficiency in pharmacoresistant depression using either high-frequency left or low-frequency right prefrontal rTMS

Background

Functional neuroimaging studies have suggested similar mechanisms underlying antidepressant effects of distinct therapeutics.

Objective

This study aimed to determine and compare functional brain patterns underlying the antidepressant response of 2 distinct protocols of repetitive transcranial magnetic stimulation (rTMS).

Methods

99mTc-ECD SPECT was performed before and after rTMS of dorsolateral prefrontal cortex in 61 drug-resistant right-handed patients with major depression, using high frequency (10 Hz) left-side stimulation in 33 patients, and low frequency (1 Hz) right-side stimulation in 28 patients. Efficiency of rTMS response was defined as at least 50% reduction of the baseline Beck Depression Inventory score. We compared the whole-brain voxel-based brain SPECT changes in perfusion after rTMS, between responders and non-responders in the whole sample (p < 0.005, uncorrected), and separately in the subgroup of patients with left- and right-stimulation.

Results

Before rTMS, the left- and right-prefrontal stimulation groups did not differ from clinical data and brain SPECT perfusion. rTMS efficiency (evaluated on % of responders) was statistically equivalent in the two groups of patients. In the whole-group of responder patients, a perfusion decrease was found after rTMS, in comparison to non-responders, within the left perirhinal cortex (BA35, BA36). This result was secondarily confirmed separately in the two subgroups, i.e. after either left stimulation (p = 0.017) or right stimulation (p < 0.001), without significant perfusion differences between these two subgroups.

Conclusions

These data show that distinct successful rTMS protocols induce equivalent brain functional changes associated to antidepressive efficiency, consisting to a remote brain limbic activity decrease within the left perirhinal cortex. However, these results will have to be confirmed in a double-blind randomized trial using a sham control group.     

3 TESLA MR imaging in adults with focal onset epilepsy

Objective

The finding of cerebral epileptogenic lesions in magnetic resonance (MR) has demonstrated to be a relevant prognostic factor for potential surgical candidates. In a series of consecutive adults with focal onset epilepsy, we investigated the yield of 3 T MR imaging for detecting epileptogenic cerebral lesions.

Materials and methods

We prospectively recruited 161 adult patients with a diagnosis of focal epilepsy, all of whom underwent standardized MR imaging study performed with a 3 T magnet.

Results

Lesion-related epilepsy was observed in 48% of patients, and 12% of cryptogenic patients showed subtle or non-specific lesions related to the epileptogenic source. The most common findings were focal cortical dysplasia and vascular lesions, followed by mesial temporal sclerosis, tumors, and scars from previous cerebral injuries. Patients older than 72 years were more likely to have vascular epilepsy.

Conclusions

Diagnostic assessment using a standardized 3 T MR imaging protocol for focal-onset epilepsy detects lesions in nearly half the patients. Our results indicate that elders with focal epilepsy should be searched for vascular lesions.     

Fatal aneurysmal subarachnoid haemorrhage: Causes of 30-day in-hospital case fatalities in a large single-centre historical patient cohort

Background

Mortality rates of up to 40% in the early phase following an aneurysmal subarachnoid haemorrhage (SAH) indicate that the overall case-fatality rate is predominantly influenced by the initial phase of the disease. This analysis investigates the in-hospital causes of death (CODs) within 30 days of admission in patients suffering from a SAH.

Methods

Of the 591 consecutive patients with SAHs from ruptured cerebral aneurysms, 85 patients who died within 30 days after admission were analysed. The various CODs were classified as cerebral or non-cerebral events. A Kaplan–Meier survival analysis was performed for the cerebral and non-cerebral CODs to identify the specific chronology of occurrence.

Results

The median cumulative fatality was 4 days. A cerebral oedema as a result of initial brain damage after ictus was the predominant COD (n = 24, 28.2%; median cumulative fatality, 1 day; IQR, 1–4 days; SEM, 0.680), followed by cerebral infarction caused by delayed cerebral ischaemia (DCI) (n = 13, 15.3%; median cumulative fatality, 9 days; IQR, 4–13 days; SEM, 1.379). Renal failure was the predominant non-cerebral COD before cardiac and pulmonary complications (n = 6, 7.1%).

Conclusions

Mortalities after SAHs predominantly occur within the first days after ictus. The dominant cerebral cause of death is early initial cerebral oedema, followed by DCI.     

Usefulness of stereotactic biopsy and neuroimaging in management of HIV-1 Clade C associated focal brain lesions with special focus on cerebral toxoplasmosis

Background

Focal brain lesions (FBL) in HIV/AIDS frequently pose a diagnostic dilemma as the etiology varies from infective (tuberculoma, toxoplasmosis and tuberculous abscesses) to neoplastic lesions like lymphoma. For determining etiology, advanced neuroimaging techniques, serological and molecular biological tests have been evolved with varying sensitivities/specificities. Stereotactic biopsy (STB) of the lesions is reserved for lesions unresponsive to appropriate therapy.

Objective and methods

In this study, the diagnostic yield of neuroimaging [cranial CT (n = 25), MRI (n = 24), and Th201/99Tc SPECT scan (n = 18)] is compared with histopathological diagnosis obtained by STB (n = 21) or autopsy (n = 4) in 25 HIV-1 subtype C seropositive individuals with FBL identified by neuroimaging with special reference to cerebral toxoplasmosis in an eighteen month study period (2006–2007).

Results and conclusion

Cerebral toxoplasmosis was the most frequent cause of FBL (21/25, 84%), followed by one case each of tuberculoma, progressive multifocal leukoencephalopathy (PML), primary central nervous system lymphoma (PCNSL) and measles inclusion body encephalitis (MIBE), the last two diagnosed at autopsy. Of the 21 cases of cerebral toxoplasmosis, definitive diagnosis with histopathological confirmation was available in 14/21 (66.6%), with indirect evidence suggesting probable toxoplasmosis in seven, all of whom responded to antitoxoplasma therapy. CT and MRI had comparable specificities (75%), while MRI had marginally higher sensitivity (85% versus 80.9%) in detecting multiple lesions. The positive predictive value of both CT and MRI was identical (94.4%), suggesting that CT maybe a cost effective screening tool in resource restricted settings, for evaluating FBL. Sensitivity of 99Tc SPECT scan for diagnosing inflammatory lesions was 75% but failed to differentiate PCNSL from toxoplasmosis. This study is the first of its kind from India analyzing FBL with specific focus on cerebral toxoplasmosis in the setting of HIV-1 subtype C.     

High-frequency rTMS treatment increases left prefrontal myo-inositol in young patients with treatment-resistant depression

Background

Neuroimaging studies suggest that the prefrontal cortex (PFC) is involved in the pathophysiology of major depression. Repetitive transcranial magnetic stimulation (rTMS) as an antidepressant intervention has increasingly been investigated in the last two decades. In this study metabolic changes within PFC of severely depressed patients before and after rTMS were evaluated by proton magnetic resonance spectroscopy (1H-MRS).

Method

Thirty-four young depressed patients with treatment-resistant unipolar depression were enrolled in a double-blind, randomized study〔active ((n = 19) vs. sham(n = 15)), and the PFC was investigated before and after high-frequency (15 Hz) rTMS using 3-tesla proton magnetic resonance spectroscopy. Response was defined as a 50% reduction of the Hamilton depression rating scale. The results were compared with 28 age- and gender-matched healthy controls.

Results

In depressive patients a significant reduction in myo-inositol (m-Ino) was observed pre-rTMS (p < 0.001). After successful treatment, m-Ino increased significantly in left PFC and the levels no longer differed from those of age-matched controls. In addition to a positive correlation between clinical improvement and an increment in m-Ino ratio, a correlation between clinical improvement and early age onset was observed.

Conclusions

Our results support the notion that major depressive disorder is accompanied by state-dependent metabolic alterations, especially in myo-inositol metabolism, which can be partly reversed by successful rTMS.     

Prevalence of cerebrovascular lesions in patients with Lewy body dementia: A neuropathological study

Background

The co-existence of vascular pathology in patients with Lewy body dementia (LBD) is still a matter of debate. This study analyses the prevalence and the severity of cerebrovascular lesions in post-mortem brains of patients with LBD.

Patients and methods

Twenty brains of demented patients with autopsy-proven Lewy body disease were compared to 14 brains of age-matched controls.

Results

Associated Alzheimer disease (AD) features, stages I–IV, were present in 70% of the LBD brains and in 7% of the controls (P < 0.001). Cerebral amyloid angiopathy (CAA) was only present in 30% and lipohyalinosis in 10%. A semi-quantitative analysis, performed on a coronal section of a whole cerebral hemisphere and on a horizontal section through the pons and the cerebellum, revealed significantly more mini-bleeds in the LBD brains (P = 0.007), predominantly in the cerebral cortex (P = 0.03). Other cerebrovascular lesions were only rarely observed. Comparison of the LDB brains, with and without moderate AD features and CAA, showed no difference in the severity of the cerebrovascular lesions including mini-bleeds.

Conclusions

The prevalence of mini-bleeds in LBD brains appears to be independent from the co-existence of moderate AD pathology and CAA. It is more probably due to disturbances of the blood–brain barrier, related to the neurodegenerative process itself.     

Cognitive dysfunctions and cerebral microbleeds in adult patients with haemophilia A: A clinical and MRI pilot-study

Background

Studies providing information about the cognitive profile of adult haemophiliacs are lacking.

Aims

To assess the neuropsychological profile in a group of Haemophiliac patients; to detect asymptomatic cerebral microbleeds (CMBs) and any correlation between CMBs and cognitive dysfunctions; to verify how several contributing factors may determine cognitive dysfunctions and/or Magnetic Resonance Imaging (MRI) findings.

Methods

Adult haemophiliacs without history of brain bleeding were prospectively enrolled on Padua Haemophilia Centre. Patients underwent: i) “Short Neuropsychological Test” assessing cognitive functions (Short Neuropsychological Examination) to obtain an overall cognitive performance (OCP) profile standardised on a cohort matched for age, sex, cultural profile; ii) MRI of the brain to evaluate areas of brain atrophy or haemorrhagic lesions. We collected information on anti-haemorrhagic treatment, cardiovascular risk profile, viral infections, birth trauma.

Results

49 adults with haemophilia (31 severe-moderate, 18 mild) were enrolled. 73% of patients presented a reduction in OCP. According to OCP, no significant difference between severe and mild haemophilia was observed though scores tended to be worse in severe haemophilia (mean Z score 0.20 ± 0.10 vs s0.15 ± 0.11). Considering risk factors, OCP correlated significantly with coronary artery disease (p = 0.02). MRI findings in 44 patients, indicated CMBs were inversely related to OCP (R = − 0.32 p < 0.05). CMBs were associated with cardiovascular risk factors (p = 0.018).

Conclusions

Adult haemophiliacs seem to present high prevalence of mild cognitive dysfunctions that doesn’t correlate with the severity of haemophilia probably for the few number of patients evaluated. OCP impairment seems to be related to the presence of CMBs and of risk factors for cardiovascular disease.     

Resting brain perfusion in alcohol-induced psychotic disorder: A comparison in patients with alcohol dependence,schizophrenia and healthy controls

Introduction

Alcohol-induced psychotic disorder (AIPD), also known as alcohol hallucinosis, is a rare complication of alcohol abuse. The underlying pathophysiology is poorly understood, and the disorder needs to be differentiated from alcohol withdrawal delirium and schizophrenia. No brain-imaging studies in AIPD have been reported to date. Case reports of brain imaging in AIPD suggest possible dysfunction in the thalamus, basal ganglia, frontal lobes and cerebellum. Our aim was to prospectively compare resting brain perfusion (rCBF) in patients with AIPD, uncomplicated alcohol dependence, schizophrenia and healthy volunteers.

Methods

Single photon emission computed tomography (SPECT) was utilized to compare rCBF in patients with AIPD (n = 19), schizophrenia (n = 16), uncomplicated alcohol dependence (n = 20) and healthy volunteers (n = 19).

Results

Increased rCBF was demonstrated in the right calcarine area in patients with AIPD compared to healthy volunteers, with a trend towards increased rCBF to the frontal and temporal lobes and the right pallidum. Decreased left sided rCBF to the putamen, parietal, mid-frontal and mid-temporal lobes and heterogenous flow to the cerebellum were demonstrated in patients with AIPD when compared to patients with uncomplicated alcohol dependence. The left posterior cingulate and right cerebellum showed higher and lower rCBF respectively in patients with AIPD compared to patients with schizophrenia.

Conclusion

Our findings implicate the right occipital lobe and possibly the cerebellum in the pathogenesis of AIPD and have similarities with those previously reported in alcohol withdrawal. Reduced rCBF to the frontal lobes, thalamus and basal ganglia in AIPD as suggested in previous case reports could not be confirmed.     

Lack of association between cerebral microbleeds and low serum cholesterol in patients with acute intracerebral hemorrhage

Background

The association of cerebral microbleeds (CMBs) with intracerebral hemorrhage (ICH) is well known and its relationship with low serum cholesterol in ICH patients might be of interest.

Methods

A total of 105 patients with ICH were evaluated. In all subjects cholesterol levels were measured after 12 h of fasting and gradient-echo magnetic resonance imaging (GE-MRI) was performed for detecting CMBs.

Results

CMBs were more common among patients with hypertension and leukoaraiosis (p = 0.008 and p = 0.001). Patients with and without CMBs did not differ according to total cholesterol, LDL cholesterol, triglycerides and HDL cholesterol levels.

Conclusion

In this study, 61% of Turkish ICH patients had CMBs, which was not associated with lipid profiles. Leukoaraiosis was independently associated with CMBs.     

Non-paretic quadriceps activity influences paretic quadriceps activity post-stroke

Objective

Inappropriate muscle activity is common following stroke. Paretic muscle activation may be influenced by non-paretic volitional activation. We examined the influence of non-paretic quadriceps activation on paretic quadriceps excitability.

Methods

Individuals with chronic stroke performed bilateral and unilateral (paretic and non-paretic) maximum voluntary isometric contractions. Peak torque and muscle activity were compared between conditions. An instrumented tendon tapper elicited a patellar tendon reflex of the relaxed paretic leg while the non-paretic leg was relaxed and pre-activated. The threshold to elicit a paretic quadriceps response was compared between conditions.

Results

During the bilateral MVIC, the paretic quadriceps generated less absolute torque, but greater relative torque than the non-paretic side when normalized to the respective unilateral condition (p < 0.05). During reflex testing, the tendon tapping threshold to elicit paretic muscle and torque responses decreased with non-paretic activity (p < 0.05).

Conclusions

Concurrent non-paretic activation resulted in a relative disinhibition of the paretic quadriceps. The paretic limb’s inability to remain inactive during isolated non-paretic contractions implies increased excitation or decreased inhibition of paretic motor pools, although the source remains unknown.

Significance

Unwanted muscle activity during reciprocal tasks (gait training) may be due to contralateral effects of non-paretic muscle activity.     

Does glycated hemoglobin have clinical significance in ischemic stroke patients?

Objectives

It has been suggested that patients with an elevated hemoglobin A1c (HbA1c) level have an increased risk of cardiovascular disease regardless of the presence of diabetes. However, an association between HbA1c and stroke has not yet been determined. In this study, our purpose was to examine whether HbA1c was independently associated with various types of cerebral vascular lesions in stroke patients.

Methods

A consecutive series of acute ischemic stroke patients were included for this analysis from October, 2002, to March, 2006. HbA1c was examined on admission, and MR imaging was performed for analysis of large artery diseases (LADs) and small artery diseases (SADs). Symptomatic or asymptomatic LAD was diagnosed by MR angiography, and SAD was classified as leukoaraiosis, microbleeds, or old lacunar infarctions.

Results

A total of 639 stroke patients were analyzed (diabetics, n = 247; non-diabetics, n = 392). There was no relationship between the level of HbA1c and any type of cerebrovascular lesion in the non-diabetic patients. In contrast, HbA1c showed a significant negative association with symptomatic LAD and leukoaraiosis in the diabetic patients using univariate analysis (p = 0.01 and p < 0.05, respectively). These associations did not remain significant, however, after adjustment for age and hypertension. This was, in part, because the HbA1c level in our diabetic population decreased gradually with age (p = 0.03).

Conclusions

Our results indicate that HbA1c is not associated with risk for various types of cerebrovascular lesions in ischemic stroke patients. The negative association between age and HbA1c in diabetic patients should be further investigated.     

Evoked magnetic fields from primary and secondary somatosensory cortices: A reliable tool for assessment of cortical processing in the neonatal period

Objective

To determine interhemispheric differences and effect of postmenstrual age (PMA), height, and gender on somatosensory evoked magnetic fields (SEFs) from the primary (SI) and secondary (SII) somatosensory cortices in healthy newborns.

Methods

We recorded SEFs to stimulation of the contralateral index finger (right in 46 and left in 12) healthy fullterm newborns and analyzed the magnetic responses with equivalent current dipoles.

Results

Activity from both the SI and SII was consistently detectable in the contralateral hemisphere of the newborns during quiet sleep. No significant interhemispheric differences existed in SI or SII response peak latencies, source strengths, or location (n = 8, quiet sleep). SI or SII response peak latency or source strength were not significantly affected by PMA, height, or gender.

Conclusions

During the neonatal period (PMA 37–44 weeks), activity from the contralateral SI and SII can be reliably evaluated with MEG. The somatosensory responses are similar in the left and right hemispheres and no corrections for exact PMA, height, or gender are necessary for interpreting the results. However, the evaluation should be conducted in quiet sleep.

Significance

The reproducibility of the magnetic SI and SII responses suggests clinical applicability of the presented MEG method.     

Interobserver variability in the detection of cerebral venous thrombosis using CT venography with matched mask bone elimination

Objectives

Computed tomography venography (CTV) has proven to be a reliable imaging method in the evaluation of cerebral venous thrombosis with good correlation to magnetic resonance (MR) imaging and digital subtraction angiography (DSA). It is fast and widely accessible, especially in the emergency setting. For better visualization of vascular structures bone is often removed from the images. The purpose of this study was to evaluate the quality of a fully automatic bone removal method, matched mask bone elimination (MMBE), and to assess the interobserver variability of the CTV technique.

Patients and methods

Fifty patients with clinical suspicion of cerebral venous thrombosis underwent multislice CTV with MMBE post-processing. Axial source images and maximum intensity projections were retrospectively evaluated by two neuroradiologists for quality of bone removal and for the presence or absence of thrombosis in nine dural sinuses and five deep cerebral veins. A per sinus/vein and a per patient analysis (thrombosis in at least one sinus or vein) was performed and interobserver agreement was assessed.

Results

Both observers considered bone removal good in all patients (100%). Interobserver agreement per patient was excellent (κ = 0.83), with a full agreement in 47 of 50 patients (94%). The interobserver agreement per sinus or vein was good (κ = 0.76), with a full agreement in 679 of 700 sinuses or veins (97%).

Conclusion

CTV aided with MMBE is a robust technique for visualization of the intracranial venous circulation, removing bone effectively. CTV has high interobserver agreement for presence or absence of cerebral venous thrombosis.     

Parent artery occlusion with bypass surgery for the treatment of internal carotid artery aneurysms: Clinical and hemodynamic results

Objective

Parent artery occlusion with/without bypass surgery is one of the treatment choices for the internal carotid artery (ICA) aneurysm difficult to treat by clipping or coiling. There have been few reports regarding postoperative cerebral blood flow (CBF) changes after surgery. This study evaluated the present bypass selection strategy based on balloon test occlusion (BTO) in terms of clinical and hemodynamic outcomes.

Methods

Twenty-one consecutive patients with ICA aneurysms underwent parent artery occlusion. High flow bypass (n = 9), superficial temporal artery–middle cerebral artery bypass (n = 10), or no bypass (n = 2) was performed depending on the changes in clinical symptoms and CBF during BTO. Quantitative CBF measurement with acetazolamide challenge was performed in the chronic stage.

Results

Overall outcome at discharge was good recovery 18, moderate disability 2, and severe disability 1. Two patients suffered symptomatic embolic or perforator infarction associated with the surgical manipulations. Preoperative cranial nerve pareses improved completely or partially in all patients except one. CBF in the chronic stage (n = 18) demonstrated no significant difference between the surgical and non-surgical cerebral hemispheres. No cerebral ischemic event was observed during the follow-up period (mean 2.9 years).

Conclusion

The present surgical strategy based on preoperative BTO provides a reliable tool to achieve acceptable clinical and hemodynamic outcomes in patients with complex ICA aneurysms to be treated by parent artery occlusion.     

Significance of triphasic waves in patients with acute encephalopathy: A nine-year cohort study

Objective

Triphasic waves (TWs) are a frequent electroencephalography (EEG) finding in encephalopathy, yet their origin and prognostic significance are not well understood. The aim of this study was to determine the clinical and EEG characteristics in encephalopathic patients with TWs. We hypothesized that specific EEG characteristics are predictive of outcome.

Methods

Consecutive adult encephalopathic patients with TWs on EEG and neuroimaging were included. EEG analysis included semiquantitative evaluation of TWs, background activity, and EEG reactivity. The study endpoint was death.

Results

Over a nine-year period, 105 patients with TWs were included. Common abnormalities on neuroimaging were white matter lesions (60%) and cerebral atrophy (59%). Pathologic conditions included infections (56%), renal (50%) and liver insufficiency (12%), and respiratory failure (20%). Mortality was 20%. Absent EEG background reactivity and respiratory failure were independently associated with death (OR 3.73, 95%CI 1.08–12.80, p = 0.037 and OR 6.47, 95%CI 1.98–21.12, p = 0.02).

Conclusions

These results suggest that TWs are a marker of structural brain disease coupled with toxic-metabolic perturbations, and that etiologies or underlying pathologies were not predictive for outcome while non-reactive EEG was independently associated with death.

Significance

In contrast to clinical, EEG and neuroimaging findings, non-reactive EEG patterns predicted death in encephalopathic patients with TWs.     

Changes in movement-related β-band EEG signals in human spinal cord injury

Objective

The purpose of this study was to characterize differences in movement-related β-band signals of the brain between people with chronic spinal cord injury (SCI) and neurologically intact volunteers.

Methods

A 64 channel EEG system was used to record EEG while subjects attempted brisk toe plantar flexion in response to auditory cues. Change in amplitude in β-band frequencies during times of event-related desynchronization and synchronization (ERD and ERS) and topography of ERD and ERS were compared across groups and correlated to ASIA motor and sensory impairment scores for SCI subjects.

Results

ERS amplitude immediately following the movement attempt was significantly smaller (t-test; p < 0.001) in SCI subjects as compared to controls. The ERD change tended to be greater and the topography was more widespread in SCI subjects. Incomplete SCI subjects with more severe neurological injury (lesser ASIA motor score) had lower peak ERS amplitude and a significant correlation was observed between sensorimotor impairments and ERS amplitude (r² = 0.79; p = 0.02).

Conclusions

Our results suggest that motor processing in the brain is altered after SCI, and that it occurs in proportion to the severity of neurological injury.

Significance

These results are important for brain computer interface applications that rely on ERD and ERS pattern recognition.