A Systematic Review of Diffusion Microstructure Imaging (Dmi): Current and Future Applications in Neurology Research (preprint)

Background: Diffusion microstructure imaging (DMI) is a novel diffusion magnetic resonance imaging (MRI) technique that provides rich estimates of microscopic tissue properties, such as axon morphologies and fiber configurations. DMI has potential applications in neurology, where various diseases and disorders affect the brain tissue's microstructure and connectivity.Objectives: To investigate the current and future applications of DMI in neurology, covering various diseases and disorders such as brain tumors and metastases, Parkinson's syndromes, COVID-19-related neurological symptoms, temporal lobe epilepsy, and acute ischemic stroke.Methods: The PRISMA 2020 statement was followed. Four electronic databases were searched from inception to May the 5th 2023. Two reviewers independently screened, selected, and extracted data from the eligible studies.Results: Seven studies were included in the review. The studies showed that DMI can differentiate between various neurological diseases or disorders based on alterations in brain tissue microstructure and connectivity. The studies also showed that DMI can be superior to conventional diffusion imaging techniques, such as diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI), in detecting subtle differences between pathological conditions.Conclusions: DMI is a powerful diffusion imaging technique that can provide rich estimates of microscopic tissue properties and differentiate between various neurological diseases or disorders. However, more research is needed to compare DMI with other imaging modalities or clinical measures and to evaluate longitudinal changes or treatment effects using DMI in neurological diseases or disorders.

Neuropathology of the temporal lobe.

Neuropathological examination of the temporal lobe provides a better understanding and management of a wide spectrum of diseases. We focused on inflammatory diseases, epilepsy, and neurodegenerative diseases, and highlighted how the temporal lobe is particularly involved in those conditions. Although all these diseases are not specific or restricted to the temporal lobe, the temporal lobe is a key structure to understand their pathophysiology. The main histological lesions, immunohistochemical markers, and molecular alterations relevant for the neuropathological diagnostic reasoning are presented in relation to epidemiology, clinical presentation, and radiological findings. The inflammatory diseases section addressed infectious encephalitides and auto-immune encephalitides. The epilepsy section addressed (i) susceptibility of the temporal lobe to epileptogenesis, (ii) epilepsy-associated hippocampal sclerosis, (iii) malformations of cortical development, (iv) changes secondary to epilepsy, (v) long-term epilepsy-associated tumors, (vi) vascular malformations, and (vii) the absence of histological lesion in some epilepsy surgery samples. The neurodegenerative diseases section addressed (i) Alzheimer's disease, (ii) the spectrum of frontotemporal lobar degeneration, (iii) limbic-predominant age-related TDP-43 encephalopathy, and (iv) α-synucleinopathies. Finally, inflammatory diseases, epilepsy, and neurodegenerative diseases are considered as interdependent as some pathophysiological processes cross the boundaries of this classification.

The impact of one-year COVID-19 containment measures in patients with mesial temporal lobe epilepsy: A longitudinal survey-based study.

BACKGROUND: We assessed levels of depression, anxiety, stress, anhedonia, somatization, psychological distress, sleep, and life quality in patients with mesial temporal lobe epilepsy (MTLE) after one year of containment measures started in Italy to stem the COVID-19 pandemic. METHODS: We consecutively enrolled 51 patients with MTLE, administering an online survey that compared the year before and after the COVID-19 propagation. We analyzed clinical data (e.g., seizure frequency, life quality) and neuropsychological assessment through Somatic Symptom Scale-8 (SSS-8), Beck Depression Inventory (BDI-2), State-Trait Anxiety Inventory (STAI-Y), Depression, Anxiety and Stress Scale (DASS-21), Pittsburgh Sleep Quality Index (PSQI), Snaith-Hamilton Pleasure Scale (SHAPS), Impact of Event Scale-Revised (IES-R). The BDI-2 and STAI-Y scores were compared to those acquired in the same patients before the COVID-19 outbreak. RESULTS: Comparing our population with MTLE before and after COVID-19 outbreak, we found a significant worsening in life quality (p = 0.03), SSS-8 (p = 0.001), BDI-2 (p = 0.032), and STAI-Y scores (p < 0.001). After one year of pandemic, 88.2% of patients obtained pathological scores at PSQI, 19.6% at SHAPS, 29.4% at IES-R. Reduction of life quality correlated with anxiety, depression, stress, and somatization. Higher levels of anhedonia correlated with stress, depression, and anxiety. Somatization correlated with depression, anxiety, and sleep quality. Distress levels correlated with anxiety, somatization, and depression. CONCLUSIONS: We demonstrated a significant worsening of depression, anxiety, life quality, and somatization in patients with MTLE after one year of COVID-19 beginning. Concomitantly, results suggest that the pandemic had a negative impact on sleep quality, psychological distress, and anhedonia, but not on epilepsy itself.

Psychological status after insulo-opercular resection in patients with epilepsy: Depression, anxiety, and quality of life.

Insular epilepsy is increasingly recognized in epilepsy surgery centers. Recent studies suggest that resection of an epileptogenic zone that involves the insula as a treatment for drug-resistant seizures is associated with good outcomes in terms of seizure control. However, despite the existing evidence of a role of the insula in emotions and affective information processing, the long-term psychological outcome of patients undergoing these surgeries remain poorly documented. A group of 27 adults (18 women) who underwent an insulo-opercular resection (in combination with a part of the temporal lobe in 10, and of the frontal lobe in 5) as part of epilepsy surgery at our center between 2004 and 2019 completed psychometric questionnaires to assess depression (Beck Depression Inventory - 2nd edition; BDI-II), anxiety (State-Trait Anxiety Inventory, Trait Version; STAI-T), and quality of life (Patient Weighted Quality of Life In Epilepsy; QOLIE-10-P). Scores were compared to those of patients who had standard temporal lobe epilepsy (TLE) surgery with similar socio-demographic and disease characteristics. Seizure control after insular epilepsy surgery was comparable to that observed after TLE surgery, with a majority of patients reporting being seizure free (insular: 63.0%; temporal: 63.2%) or having rare disabling seizures (insular: 7.4%; temporal: 18.4%) at the time of questionnaire completion. Statistical comparisons revealed no significant group difference on scores of depression, anxiety, or quality of life. Hemisphere or extent of insular resection had no significant effect on the studied variables. In the total sample, employment status and seizure control, but not location of surgery, significantly predicted quality of life. Self-reported long-term psychological status after insulo-opercular resection as part of epilepsy surgery thus appears to be similar to that observed after TLE surgery, which is commonly performed in epilepsy surgery centers.

Acutely Altered Mental Status as the Main Clinical Presentation of Multiple Strokes in Critically Ill Patients With COVID-19. (preprint)

Background and aims:Cerebral infarction in COVID-19 patients might be associated with a hypercoagulable state related to a systemic inflammatory response. Its diagnosis might be challenging. We present two critically ill patients with COVID-19 who presented acutely altered mental status as the main manifestation of multiple strokes.Methods:Clinical presentation and diagnostic work-up of the patients.Results:Two patients in their sixties were hospitalized with a bilateral pneumonia COVID-19. They developed respiratory failure and were admitted to ICU for mechanical ventilation and intense medical treatment. They were started on low-molecular-weight heparin since admission. Their laboratory results showed lymphopenia and increased levels of C-reactive protein and D-dimer. Case 1 developed hypofibrinogenemia and presented several cutaneous lesions with biopsy features of thrombotic vasculopathy. Case 2 was performed a CT pulmonary angiogram at ICU showing a bilateral pulmonary embolism. When waking up, both patients were conscious but with a remarkable global altered mental status without focal neurological deficits. A brain MRI revealed multiple acute bilateral ischemic lesions with areas of hemorrhagic transformation in both patients (Case 1: affecting the left frontal and temporal lobes and both occipital lobes; Case 2: affecting both frontal and left occipital lobes). Cardioembolic source and acquired antiphospholipid syndrome were ruled out. COVID-19-associated coagulopathy was suspected as the possible main etiology of the strokes.Conclusion:Acutely altered mental status might be the main manifestation of multiple brain infarctions in critically ill COVID-19 patients. It should be specially considered in those with suspected COVID-19-associated coagulopathy. Full-dose anticoagulation and clinical-radiological monitoring might reduce their neurological consequences.