Correlation of postmortem MRI and CT appearances with neuropathology in brain trauma: a comparison of two methods

Prolonged, Low-Level Exposure to the Marine Toxin, Domoic Acid, and Measures of Neurotoxicity in Nonhuman Primates

BACKGROUND

The excitotoxic molecule, domoic acid (DA), is a marine algal toxin known to induce overt hippocampal neurotoxicity. Recent experimental and epidemiological studies suggest adverse neurological effects at exposure levels near the current regulatory limit (20 ppm, ∼0.075-0.1mg/kg). At these levels, cognitive effects occur in the absence of acute symptoms or evidence of neuronal death.

OBJECTIVES

This study aimed to identify adverse effects on the nervous system from prolonged, dietary DA exposure in adult, female Macaca fascicularis monkeys.

METHODS

Monkeys were orally exposed to 0, 0.075, and 0.15mg/kg per day for an average of 14 months. Clinical blood counts, chemistry, and cytokine levels were analyzed in the blood. In-life magnetic resonance (MR) imaging assessed volumetric and tractography differences in and between the hippocampus and thalamus. Histology of neurons and glia in the fornix, fimbria, internal capsule, thalamus, and hippocampus was evaluated. Hippocampal RNA sequencing was used to identify differentially expressed genes. Enrichment of gene networks for neuronal health, excitotoxicity, inflammation/glia, and myelin were assessed with Gene Set Enrichment Analysis.

RESULTS

Clinical blood counts, chemistry, and cytokine levels were not altered with DA exposure in nonhuman primates. Transcriptome analysis of the hippocampus yielded 748 differentially expressed genes (fold change≥1.5; p≤0.05), reflecting differences in a broad molecular profile of intermediate early genes (e.g., FOS, EGR) and genes related to myelin networks in DA animals. Between exposed and control animals, MR imaging showed comparable connectivity of the hippocampus and thalamus and histology showed no evidence of hypomyelination. Histological examination of the thalamus showed a larger microglia soma size and an extension of cell processes, but suggestions of a GFAP+astrocyte response showed no indication of astrocyte hypertrophy.

DISCUSSION

In the absence of overt hippocampal excitotoxicity, chronic exposure of Macaca fascicularis monkeys to environmentally relevant levels of DA suggested a subtle shift in the molecular profile of the hippocampus and the microglia phenotype in the thalamus that was possibly reflective of an adaptive response due to prolonged DA exposure. https://doi.org/10.1289/EHP10923.

"Don't lose hope early": Hemorrhagic diffuse axonal injury on head computed tomography is not associated with poor outcome in moderate to severe traumatic brain injury patients

BACKGROUND

Diffuse axonal injury (DAI) on magnetic resonance imaging has been associated with poor functional outcome after moderate-severe traumatic brain injury (msTBI). Yet, DAI assessment with highly sensitive magnetic resonance imaging techniques is unfeasible in the acute trauma setting, and computed tomography (CT) remains the key diagnostic modality despite its lower sensitivity. We sought to determine whether CT-defined hemorrhagic DAI (hDAI) is associated with discharge and favorable 3- and 12-month functional outcome (Glasgow Coma Scale score ≥4) after msTBI.

METHODS

We analyzed 361 msTBI patients from the single-center longitudinal Outcome Prognostication in Traumatic Brain Injury study collected over 6 years (November 2009 to November 2015) with prospective outcome assessments at 3 months and 12 months. Patients with microhemorrhages on CT were designated "CT-hDAI-positive" and those without as "CT-hDAI-negative." For secondary analyses "CT-hDAI-positive" was stratified into two phenotypes according to presence ("associated") versus absence ("predominant") of concomitant large acute traumatic lesions to determine whether presence versus absence of additional focal mass lesions portends a different prognosis.

RESULTS

Seventy (19%) patients were CT-hDAI-positive (n = 36 predominant; n = 34 associated hDAI). In univariate analyses, CT-hDAI-positive status was associated with discharge survival (p = 0.004) and favorable outcome at 3 months (p = 0.003) and 12 months (p = 0.005). After multivariable adjustment, CT-hDAI positivity was no longer associated with discharge survival and functional outcome (all ps > 0.05). Stratified by hDAI phenotype, predominant hDAI patients had worse trauma severity, longer intensive care unit stays, and more systemic medical complications. Predominant hDAI, but not associated hDAI, was an independent predictor of discharge survival (adjusted odds ratio, 24.7; 95% confidence interval [CI], 3.2-192.6; p = 0.002) and favorable 12-month outcome (adjusted odds ratio, 4.7; 95% CI, 1.5-15.2; p = 0.01). Sensitivity analyses using Cox regression confirmed this finding for 1-year survival (adjusted hazard ratio, 5.6; 95% CI, 1.3-23; p = 0.048).

CONCLUSION

The CT-defined hDAI was not an independent predictor of unfavorable short- and long-term outcomes and should not be used for acute prognostication in msTBI patients. Predominant hDAI patients had good clinical outcomes when supported to intensive care unit discharge and beyond.

LEVEL OF EVIDENCE

Prognostic study, level III.

Post-Mortem MRI and Histopathology in Neurologic Disease: A Translational Approach

In this review, combined post-mortem brain magnetic resonance imaging (MRI) and histology studies are highlighted, illustrating the relevance of translational approaches to define novel MRI signatures of neuropathological lesions in neuroinflammatory and neurodegenerative disorders. Initial studies combining post-mortem MRI and histology have validated various MRI sequences, assessing their sensitivity and specificity as diagnostic biomarkers in neurologic disease. More recent studies have focused on defining new radiological (bio)markers and implementing them in the clinical (research) setting. By combining neurological and neuroanatomical expertise with radiological development and pathological validation, a cycle emerges that allows for the discovery of novel MRI biomarkers to be implemented in vivo. Examples of this cycle are presented for multiple sclerosis, Alzheimer's disease, Parkinson's disease, and traumatic brain injury. Some applications have been shown to be successful, while others require further validation. In conclusion, there is much to explore with post-mortem MRI and histology studies, which can eventually be of high relevance for clinical practice.

Sexual Dysfunctions in Female with Neurological Disorders

Female sexuality is a controversial issue due to its embarrassment and to paucity of literature publications. The neuroanatomy and neuromediators involved in female sexuality are important but not so fundamental as in men. There are three sexual female dysfunctions (SFD): primary, secondary, tertiary. In the primary one, the sexual dysfunction (SD) is correlated to the neurological disease, in the secondary the SD derives from the symptoms of the neurological disease, in the tertiary the SD is the psychological reaction to the effects of the disease. We analyse the FSD in neurological diseases, as the outcome of medulla trauma, multiple sclerosis, epilepsy, Alzheimer, Parkinson, diabetes, outcome of pelvic surgery. Female sexuality (FS) is difficult and complex compared to male sexuality. Women with medulla lesion feel some discomfort when having to go and speak to their doctor: they are afraid of pregnancy, sexual intercourses, bladder and rectal functions. In women with newly diagnosed multiple sclerosis, there is a tertiary sexual dysfunction. Medical therapy worsens female sexuality as in case of epilepsy. Emotional and behavioural disorders involve sexual dysfunctions in women with Alzheimer. In Parkinson, reduction of sexual desire involves break of sexual intercourses. SD are more frequent in complicated diabetes. In pelvic surgery, pelvic autonomic dysfunction and depression correlated to the oncology disease, contribute to the FSD. Sexual counselling, especially in young women with medulla lesion or multiple sclerosis, is the best therapy, and learning erotic extragenital areas able to make sensations similar to the orgasms.

Diffusion tensor imaging in acute-to-subacute traumatic brain injury: a longitudinal analysis

BACKGROUND

Diffusion tensor imaging (DTI) may have prognostic utility in patients with traumatic brain injury (TBI), but the optimal timing of DTI data acquisition is unknown because of dynamic changes in white matter water diffusion during the acute and subacute stages of TBI. We aimed to characterize the direction and magnitude of early longitudinal changes in white matter fractional anisotropy (FA) and to determine whether acute or subacute FA values correlate more reliably with functional outcomes after TBI.

METHODS

From a prospective TBI outcomes database, 11 patients who underwent acute (≤7 days) and subacute (8 days to rehabilitation discharge) DTI were retrospectively analyzed. Longitudinal changes in FA were measured in 11 white matter regions susceptible to traumatic axonal injury. Correlations were assessed between acute FA, subacute FA and the disability rating scale (DRS) score, which was ascertained at discharge from inpatient rehabilitation.

RESULTS

FA declined from the acute-to-subacute period in the genu of the corpus callosum (0.70 ± 0.02 vs. 0.55 ± 0.11, p < 0.05) and inferior longitudinal fasciculus (0.54+/-0.07 vs. 0.49+/-0.07, p < 0.01). Acute correlations between FA and DRS score were variable: higher FA in the body (R = -0.78, p = 0.02) and splenium (R = -0.83, p = 0.003) of the corpus callosum was associated with better outcomes (i.e. lower DRS scores), whereas higher FA in the genu of the corpus callosum (R = 0.83, p = 0.02) corresponded with worse outcomes (i.e. higher DRS scores). In contrast, in the subacute period higher FA in the splenium correlated with better outcomes (R = -0.63, p < 0.05) and no inverse correlations were observed.

CONCLUSIONS

White matter FA declined during the acute-to-subacute stages of TBI. Variability in acute FA correlations with outcome suggests that the optimal timing of DTI for TBI prognostication may be in the subacute period.

Forensic application of postmortem diffusion-weighted and diffusion tensor MR imaging of the human brain in situ

BACKGROUND AND PURPOSE

DWI and DTI of the brain have proved to be useful in many neurologic disorders and in traumatic brain injury. This prospective study aimed at the evaluation of the influence of the PMI and the cause of death on the ADC and FA for the application of DWI and DTI in forensic radiology.

MATERIALS AND METHODS

DWI and DTI of the brain were performed in situ in 20 deceased subjects with mapping of the ADC and FA. Evaluation was performed in different ROIs, and the influence of PMI and cause of death was assessed.

RESULTS

Postmortem ADC values of the brain were decreased by 49%-72% compared with healthy living controls. With increasing PMI, ADCs were significantly reduced when considering all ROIs together and, particularly, GM regions (all regions, P < .05; GM, P < .01), whereas there was no significant effect in WM. Concerning the cause of death, ADCs were significantly lower in mechanical and hypoxic brain injury than in brains from subjects having died from heart failure (traumatic brain injury, P < .005; hypoxia, P < .001). Postmortem FA was not significantly different from FA in living persons and showed no significant influence of PMI or cause of death.

CONCLUSIONS

Performing postmortem DWI and DTI of the brain in situ can provide valuable information for application in forensic medicine. ADC could be used as an indicator of PMI and could help in the assessment of the cause of death.

Exploring new routes for neuroprotective drug development in traumatic brain injury

Worldwide, traumatic brain injury (TBI) is a major cause of mortality and morbidity with a substantial predicted increase in incidence. Despite an obvious need, there are no pharmacological treatment options for TBI because translation of neuroprotection from preclinical studies to clinical practice has so far failed. Here, we identify potential causes for this failure. We suggest that the monitoring and investigation tools that are commonly used in patients with TBI may provide an experimental medicine route to facilitate a more rational approach to translational research. This suggestion is underpinned by existing research data on disease biology, drug delivery, and treatment response obtained with these methods.

Whole-brain proton MR spectroscopic imaging of mild-to-moderate traumatic brain injury and correlation with neuropsychological deficits

Changes in the distribution of the magnetic resonance (MR)-observable brain metabolites N-acetyl aspartate (NAA), total choline (Cho), and total creatine (Cre), following mild-to-moderate closed-head traumatic brain injury (mTBI) were evaluated using volumetric proton MR spectroscopic imaging (MRSI). Studies were carried out during the subacute time period following injury, and associations of metabolite indices with neuropsychological test (NPT) results were evaluated. Twenty-nine subjects with mTBI and Glasgow Coma Scale (GCS) scores of 10-15 were included. Differences in individual metabolite and metabolite ratio distributions relative to those of age-matched control subjects were evaluated, as well as analyses by hemispheric lobes and tissue types. Primary findings included a widespread decrease of NAA and NAA/Cre, and increases of Cho and Cho/NAA, within all lobes of the TBI subject group, and with the largest differences seen in white matter. Examination of the association between all of the metabolite measures and the NPT scores found the strongest negative correlations to occur in the frontal lobe and for Cho/NAA. No significant correlations were found between any of the MRSI or NPT measures and the GCS. These results demonstrate that significant and widespread alterations of brain metabolites occur as a result of mild-to-moderate TBI, and that these measures correlate with measures of cognitive performance.

Sex and gender in older adults' experience of Parkinson's disease

OBJECTIVES

This article reports on the gendered experience of Parkinson's disease (PD). Data derived from 15 months of ethnographic study among community-dwelling older adults living with PD in eastern Iowa.

METHODS

The study utilized several methods: participant observation at PD support group meetings, illness narrative interviews with PD sufferers, and a questionnaire.

RESULTS

A total of 171 PD sufferers (106 men, 65 women) enrolled in the study. Illness narratives revealed gender differences in the impact of specific symptoms on daily life: Women's narratives emphasized the impact of the on/off effect and "thinking problems," whereas men's narratives emphasized the consequences of their physical appearance. In comparison, quantitative data found little sex difference in symptomatology.

DISCUSSION

The comparison of qualitatively and quantitatively derived data reveals the importance of attending to both sex and gender. Qualitative data demonstrate how the meaning of PD symptoms is gendered and illustrate an example of how gender and sex research differ. All narratives reflect the importance of role continuity, but men's put at the forefront appearance and social isolation whereas women's underscore their relational aspects of domestic activities. These data imply that providers must look beyond symptomatology to the gendered saliency of particular somatic phenomena.

Botanical therapies in sexual dysfunction

Sexual dysfunction is a serious medical and social symptom that occurs in 10%-52% in men and 25%-63% in women. Numerous central and peripheral neural circuits control sexual activity. Impairment of one or more of these functional circuits may have a significant impact on personal, social and biological relationships. Although several aspects of sexual motivation and performance are known, a complete picture of the various factors that control human sexual activity is still unknown. The available drugs and treatments have limited efficacy, unpleasant side effects and contraindications in certain disease conditions. A variety of botanicals are known to have a potential effect on the sexual functions, supporting older claims and offering newer hopes. This review, while evaluating various factors that control sexual function, identifies a variety of botanicals that may be potentially useful in treating sexual dysfunction.

Pergolide mesylate can improve sexual dysfunction in patients with Parkinson's disease: the results of an open, prospective, 6-month follow-up

One of the most disabling problems in males suffering from advanced Parkinson's disease (PD) is complex sexual dysfunction. The effect of dopamine replacement or dopaminergic stimulation on sexual dysfunction has been recently examined and described in patients treated by L-DOPA or apomorphine. Pergolide mesylate is another dopamine agonist with a known high affinity to hD(2S) subtype and a lower affinity to hD(2L) subtype of D2 dopaminergic receptors. It has been repeatedly shown to be a highly effective treatment of the complicated and advanced stages of PD. The current study has been designed to assess its efficacy in the treatment of sexual dysfunction, which frequently accompanies the complicated stage of PD in males. Fourteen male patients suffering from PD, each of whom had been treated with L-DOPA, and in whom additional treatment with peroral dopaminergic agonist (DA) was needed, were followed for a 6-month period. Pergolide mesylate (Permax) was given to each patient, and titrated to a total daily dose of 3 mg. All of the patients were taking L-DOPA. The assessments performed before the start of pergolide treatment consisted of a neurological examination, including Unified Parkinson's Disease Rating Scale (UPDRS) III and IV subscales scoring, Mini Mental State Examination (MMSE) scoring, the neuropsychological examination including Zung scale scoring to exclude depression, biochemical and haematological examinations including the examination of prolactine serum levels; and a sexological examination during which the patients filled-in the International Index of Erectile Function (IIEF) questionnaire. These examinations were repeated during the control assessments at months 1, 3 and 6. To compare the examination results, anova, Friedmann's anova (non-parametric) and Tukey post hoc tests were used. There were statistically significant differences between the values of UPDRS III motor subscale, UPDRS IV (complications of therapy) subscale and all subscales of IIEF when months 0 and 1 were compared with the results obtained at months 3 and 6. The differences between months 0 and 1 and months 3 and 6 (in these items) were virtually insignificant. In conclusion, pergolide substantially improved sexual function in the younger male patients who were still interested in sexual activities. In such cases, the introduction of pergolide might be a better choice than treatment with sildenafile, which usually meets several contraindications in common PD male population.