Receptor for Advanced Glycation End Product, Organ Crosstalk, and Pathomechanism Targets for Comprehensive Molecular Therapeutics in Diabetic Ischemic Stroke

Diabetes mellitus, a well-established risk factor for stroke, is related to higher mortality and poorer outcomes following the stroke event. Advanced glycation end products(AGEs), their receptors RAGEs, other ligands, and several other processes contribute to the cerebrovascular pathomechanism interaction in the diabetes-ischemic stroke combination. Critical reappraisal of molecular targets and therapeutic agents to mitigate them is required to identify key elements for therapeutic interventions that may improve patient outcomes. This scoping review maps evidence on the key roles of AGEs, RAGEs, other ligands such as Leukotriene B4 (LTB4), High-mobility group box 1 (HMGB1) nuclear protein, brain-kidney-muscle crosstalk, alternate pathomechanisms in neurodegeneration, and cognitive decline related to diabetic ischemic stroke. RAGE, HMGB1, nitric oxide, and polyamine mechanisms are important therapeutic targets, inflicting common consequences of neuroinflammation and oxidative stress. Experimental findings on a number of existing-emerging therapeutic agents and natural compounds against key targets are promising. The lack of large clinical trials with adequate follow-up periods is a gap that requires addressing to validate the emerging therapeutic agents. Five therapeutic components, which include agents to mitigate the AGE-RAGE axis, improved biomarkers for risk stratification, better renal dysfunction management, adjunctive anti-inflammatory-antioxidant therapies, and innovative neuromuscular stimulation for rehabilitation, are identified. A comprehensive therapeutic strategy that features all the identified components is needed for outcome improvement in diabetic stroke patients.

Mononeuritis Multiplex as Initial Manifestation of Pure Neuritic Leprosy-A Forgotten Cause: Clinical, Electrodiagnostic and Pathologic Correlations

Despite being common, polyneuropathy remains a diagnostic challenge for most clinicians. Mononeuritis multiplex (MM) refers to involvement of several or many peripheral nerves at the same or different points in time by a disease process. This report describes a case of an atypical presentation of Hansen's disease (HD) as mononeuritis multiplex in the left lower limb with corresponding radiographic, electrodiagnostic, and histopathological data that confirmed pure neuritic leprosy (PNL). We reiterate that although the incidence of PNL is exceedingly low characterized by nerve involvement without the characteristic cutaneous stigmata, leprosy is still the commonest cause of MM in the Indian sub-continent.This report underscores the crucial need for a heightened multi-disciplinary awareness of this "forgotten and uncommon" presentation of PNL. It is imperative that the treating physician should also understand the various neurological presentations, both mimics and chameleons, of this treatable disease to prevent permanent neuropathic injury and disability.

Selective Hand Motor Cortex Lesions Masquerading as "Pseudoperipheral Nerve Palsy"

Strategic cortical lesions involving the hand motor cortex (HMC) presenting acutely as distal upper limb pure motor weakness certainly do need to be differentiated on clinical grounds from “pseudoperipheral palsy.” This rare phenotype can imitate peripheral motor nerve deficits and should not be easily overlooked. The isolated “central hand and finger weakness” presenting as an acute onset of varying combinations such as pseudomedian, pseudoradial, and/or pseudoulnar nerve palsy is intriguing to the novice. In literature, this phenotype has been reported solely to result from cortical cerebral infarction and documented to occur in <1% of all ischemic strokes. The apropos of six “unforgettable patients” here highlights the heterogeneous pathophysiologic etiologies and mechanisms that included not only the conventional stroke risk factors but also hyperhomocysteinemia, common carotid artery thrombosis due to hyperhomocysteinemia and severe iron-deficiency anemia, biopsy-proven giant cell arteritis (GCA), cerebral metastasis, and dilated cardiomyopathy-related left ventricular thrombosis. Physicians and neurologists alike, as clinicians, need to be familiar with the peculiarities and clinical presentations of central hand control network cortical lesions.

Hyperacute Paraplegia and Neurovascular (Immuno Vasculotoxic) Catastrophe of Nicolau Syndrome: Primum Non nocere

A case of Nicolau syndrome (NS) in a 36-year-old adult taking an unusual and devastating hyperacute irreversible paraplegia after an intramuscular injection of benzathine penicillin as a part of routine chemoprophylaxis of her rheumatic heart disease is reported. Although this syndrome is a considerably rare, iatrogenic and underappreciated dermatologic entity, we reiterate in this report, its extracutaneous systemic potential for a catastrophic neurovascular phenomenon and morbidity as well as its possible preventive measures. The apoplectiform onset of T10 flaccid areflexic paraplegia, with the cutaneous hallmark of "embolia cutis medicamentosa" was corroborated by magnetic resonance imaging evidence of centromedullary complete cord involvement from T10 to conus medullaris. Combination therapy with pulse methylprednisolone, low-molecular-weight heparin, and pentoxifylline infusion proved unsuccessful. The skin biopsy and direct immunofluorescence revealed features were consistent with NS with overlap features of leukocytoclastic vasculitis, hitherto not reported. The literature of this preventable and iatrogenic disorder is reviewed, and plausible etiology is discussed.

Preventing "Neurophobia": Remodeling Neurology Education for 21st-Century Medical Students through Effective Pedagogical Strategies for "Neurophilia"

Neurology has a reputation, particularly as a complex "head-to-toe" discipline for undergraduate medical students. Neurophobia syndrome, a global phenomenon, fundamentally stems from pedagogical deficiencies during the undergraduate curriculum, the lack of vertical integration between basic neurosciences and clinical bedside neurology, the lack of clinical reasoning exercises, cognitive heuristics, and clinical problem-solving, errors in diagnostic competence, and hyposkilia. This ultimately results in poor clinical competence and proficiency in clinical neurology and causes attrition in nurturing a passion for learning the neurology discipline. This article explores plausible factors that contribute to the genesis of neurophobia and multifaceted strategies to nurture interest in neurosciences and provide possible solutions to demystify neurology education, especially the need for evidence-based educational interventions. Remodeling neurology education through effective pedagogical strategies and remedial measures, and using the Miller's pyramid, would provide a framework for assessing clinical competence in clinical bedside neurology. Technology-enhanced education and digital classrooms would undoubtedly stamp out neurophobia in medical students of the 21^st century. It will not frighten off another generation of nonneurologist physicians to empower them to hone expertise in order to tackle the increasing burden of neurological disorders in India. Furthermore, promoting neurophilia would facilitate the next generation of medical students in pursuing career options in neurology which would be quintessential not only in closing India's looming neurologist workforce gap but also in fostering interest in research imperatives in the next generation of medical students.

Is the pathology of corticobasal syndrome predictable in life?

Corticobasal syndrome (CBS) has been associated with a heterogeneous spectrum of pathologies with an increasing number of reports of Alzheimer's type pathology. There is, however, no means of predicting pathology of CBS in vivo at present. We compared the clinical features of patients presenting with CBS who have either pathologic changes of classic corticobasal degeneration (CBD) or Alzheimer's disease (AD) at post-mortem to identify predictors of the specific pathological processes in life. Twelve patients with CBS were followed prospectively; six had AD and six had classic CBD neuropathology. After review of the presenting clinical features, we identified nine potential predictor variables, compared their frequency in the two groups, and performed a discriminant function analysis. Initial episodic memory complaints and poor performance on the combined orientation-memory subtest of the Addenbrooke's Cognitive Examination (ACE) reliably predicted AD pathology while varying combinations of early frontal-lobe type behavioral symptoms, nonfluent language disturbance, orobuccal apraxia, and utilization behavior predicted CBD pathology ante-mortem. CBS is frequently associated with Alzheimer's disease pathology. Early episodic memory impairment versus early behavioral symptomatology appears to best predict AD or CBD pathology in life.

"All that spikes is not fits", mistaking the woods for the trees: the interictal spikes--an "EEG chameleon" in the interface disorders of brain and mind: a critical review

Recent research into mammalian cortical neurophysiology, after 6 decades of Berger's seminal work on electroencephalography, has shifted the older concept of interictal epileptiform activity (IEA) away from that of a mere electrographic graphoelement of relevance to diagnostic implications in epilepsy. Instead, accumulating information has stressed the neuropsychological implications, cognitive and/or behavioral consequence of these electrophysiological events, which are the phenotypic expression of aberrations of actual biophysical cellular function. We feel that this review is germane to neuropsychiatry, however, a rather neglected area of research. There is a great scope for brain-behavior-EEG research in the future that can be complimented by other techniques of "neurobehavioral electrophysiology". This review does not address the "pearls, perils and pitfalls" in the use of EEG in epilepsy, but critically and systematically reappraises the published electroencephalographic correlates of human behavior. We reiterate that epileptiform and other paroxysmal EEG dysrhythmias unrelated to clinical seizures do have neuropsychological, cognitive and/or behavioral implications as seen in the various neuropsychiatric and neurobehavioral disorders discussed in this article. IEA and EEG dysrhythmias should neither be ignored as irrelevant nor automatically attributed to epilepsy. The relevance of these EEG aberrations in the disorders of the brain-mind interface extend beyond epilepsy, and may be an electrophysiological endophenotype of aberrant neuronal behavior indicative of underlying morpho-functional brain abnormalities. Magnetoencephalography (MEG), data fusion models (EEG-fMRI-BOLD), transcranial magnetic stimulation (TMS), evoked potentials (EP); intracranial electrophysiology, and EEG neurofeedback complemented by current functional neuroimaging techniques (fMRI and PET) would certainly help in further understanding the broader relationship between brain and behavior.

Can progressive and non-progressive behavioural variant frontotemporal dementia be distinguished at presentation?

BACKGROUND

Recent findings suggest that patients with behavioural variant frontotemporal dementia (bv-FTD) differ in their disease progression (progressive vs non-progressive patients). The current study investigates whether the two groups can be discriminated by their clinical features at first presentation.

METHODS

Archival clinical data of the Early Onset Dementia Clinic, Cambridge, UK, were analysed for 71 patients with bv-FTD: 45 progressive and 26 non-progressive cases with more than 3 years of follow-up.

RESULTS

The subgroups were largely indistinguishable on the basis of the presenting clinical features but could be distinguished on general cognitive (Addenbrooke's Cognitive Examination-revised) and selected supportive diagnostic features (distractibility, stereotypic speech, impaired activities of daily living (ADLs) and current depression).

CONCLUSIONS

Progressive and non-progressive patients are difficult to differentiate on the basis of current clinical diagnostic criteria for FTD but a combination of general cognitive, executive dysfunction and impaired ADL measures appear to be the most promising discriminators.

Sensitivity of current criteria for the diagnosis of behavioral variant frontotemporal dementia

BACKGROUND

Diagnosis of behavioral variant frontotemporal dementia (bvFTD) relies on criteria that are constraining and potentially ambiguous. Some features are open to clinical interpretation and their prevalence unknown. This study investigated the sensitivity of current diagnostic criteria in a large group of patients with bvFTD.

METHODS

Forty-five patients with clear evidence of bvFTD as judged by progressive clinical decline (>3 years) with marked frontal features and significant frontal brain atrophy on brain MRI were included. Thirty-two have died; pathologic confirmation of frontotemporal lobar degeneration was found in all 18 coming to autopsy. We established the prevalence of core and supportive diagnostic features at presentation and with disease progression.

RESULTS

Only 25/45 patients (56%) showed all five core features necessary for a diagnosis of bvFTD at initial presentation and 33/45 (73%) as their disease progressed. Two core features, emotional blunting and loss of insight, were never observed in 25% and 13% of cases. Executive dysfunction, hyperorality, mental inflexibility, and distractibility were the only supportive features present in >50% of cases at initial presentation. Although not a diagnostic feature, impaired activities of daily living was present in 33/45 patients (73%).

CONCLUSIONS

Strict application of the criteria misses a significant proportion of patients. Many supportive features have low prevalence and are clinically not useful. Revision of the criteria to include level of certainty (definite, probable, possible) dependent on the number of features present and the presence of ancillary information (e.g., brain atrophy, neuropsychological abnormalities, impaired activities of daily living) is encouraged.

Electroencephalographic cerebral dysrhythmic abnormalities in the trinity of nonepileptic general population, neuropsychiatric, and neurobehavioral disorders

Subclinical electroencephalographic epileptiform discharges in neurobehavioral disorders are not uncommon. The clinical significance and behavioral, diagnostic, and therapeutic implications of this EEG cerebral dysrhythmia have not been fully examined. Currently the only connotation for distinctive epileptiform electroencephalographic patterns is epileptic seizures. Given the prevailing dogma of not treating EEGs, these potential aberrations are either disregarded as irrelevant or are misattributed to indicate epilepsy. This article reappraises the literature on paroxysmal EEG dysrhythmia in normative studies of the "healthy" nonepileptic general populations, neuropsychiatry, and in neurobehavioral disorders. These EEG aberrations may be reflective of underlying morpho-functional brain abnormalities that underpin various neurobehavioral disturbances.

The spectrum of dementia: frequency, causes and clinical profile. A national referral hospital-based study in Oman

BACKGROUND AND OBJECTIVE

There is a paucity of epidemiological data on dementia in the Arabian Peninsular region, particularly Oman. To determine the spectrum, clinical profile, and the behavioral manifestations of dementia in Omani patients evaluated at a tertiary referral hospital.

METHODS

We retrospectively reviewed the demographic and clinical spectrum of 116 patients with probable dementia diagnosed in this center. The diagnosis of dementia was made according to DSM-IV criteria, and staged according to the Clinical Dementia Rating scale. Exclusion criteria included psychiatric disorders, cranial trauma, cerebral tumors, and mild cognitive impairment. The vascular risk patterns and behavioral data were analyzed.

RESULTS

Alzheimer's disease was observed to be the commonest dementia subtype seen in 61 patients (52.6%), while 24.1% had vascular dementia and 9.5% constituted frontotemporal lobar degeneration. Early onset dementia was seen in 45% and potentially reversible dementia constituted 8.6%. Behavioral and psychopathological disturbances in dementia appear to be universal with certain differentiating features between the three major subtypes of dementia.

CONCLUSIONS

This is the first published report of dementia from Oman. Dementia is an important health problem not only of the elderly but also of the young population in Oman.

Frontotemporal dementia in Oman: Cognitive behavioural profile and neuroimaging characteristics; A prospective hospital-based study

Frontotemporal dementia is increasingly recognised as an important cause of early-onset dementia and is considered to be the second commonest neurodegenerative dementia after Alzheimer's disease. We describe the cognitive, behavioural profile and neuroimaging characteristics of 6 patients with frontal variant of Frontotemporal dementia that were evaluated at the cognitive behavioural clinic at this tertiary referral teaching hospital. All patients underwent clinical, neuropsychological, structural/functional neuroimaging, and laboratory evaluations. The male to female ratio was 1:1; mean age of onset was 54 years, and the mean duration of symptoms were 30 months. The mean scores for Addenbrooke's cognitive examination, Frontal Assessment Battery, and Mini-Mental State Examination were 70.5, 6.33 and 23.6 respectively. The mean VLOM ratio was 2.04. MRI revealed significant asymmetrical regional frontal/temporal atrophy supplemented by the evidence of circumscribed hypoperfusion in SPECT imaging. We conclude that a combination of behavioural and cognitive assessment using short bedside tests, along with structural and functional neuroimaging does facilitate early identification, and increase the diagnostic specificity of Frontotemporal dementia.

An individual with Gilles de la Tourette syndrome and Smith-Magenis microdeletion syndrome: is chromosome 17p11.2 a candidate region for Tourette syndrome putative susceptibility genes?

This is the first published case description in the current literature of the association of definite Gilles de la Tourette syndrome (GTS) and the Smith-Magenis syndrome (SMS), both confirmed by DSM-IV-TR criteria and molecular cytogenetic analysis, respectively. The co-occurrence of GTS, SMS and their common behavioural/neuropsychiatric abnormalities should warrant further genetic investigation of chromosome 17p11.2 deletion site as it may be a promising region for containing a gene(s) of aetiological importance in the development of the GTS phenotype. Alternatively, the co-occurrence may be due to the common endophenotypic mechanisms shared by these disorders, rather than being specific for GTS that could be explored using strategies of quantitative trait loci - endophenotype-based approach. Research into this genomic region may also benefit psychiatric genetic research in enhancing understanding of the biological and molecular underpinnings of common behavioural problems that are seen in both GTS and SMS. This would lead to advancement in neurobehavioural/neuropsychiatric genetics which will help in further explaining the broader perspective of gene-brain-behaviour interrelationships.

An unusual late complication of intracerebral haematoma in herpes encephalitis after successful acyclovir treatment

This is a case report of PCR proven herpes simplex (HSV-1) encephalitis in a 26 years old immunocompetent adult taking an unusual course of acute intracerebral haematoma after successful and complete recovery with acyclovir therapy. This transient late complication was associated with a negative repeat CSF PCR for HSV suggesting that the initial 14 days course of acyclovir was successful in the eradication of the herpes virus infection as recommended by the International Herpes Management Forum (IHMF). The location of the haematoma corresponded to the initial encephalitic area involving the medial temporal lobe structures. Despite this late neuroradiologic complication, after day 18 of symptom onset, the patient had a favourable neurological outcome. To the best of our knowledge, this is the second report of the unusual, rare, and late neuroimaging complication of acute intracerebral haematoma formation after complete recovery from treated HSVE with favourable clinical outcome. The literature is reviewed and plausible aetiology is discussed.

The neuropsychiatry and multisystem features of the Smith-Magenis syndrome: a review

Smith-Magenis Syndrome (SMS) is a complex, pediatric, neurobehavioral, contiguous gene syndrome ascribed to interstitial microdeletion of chromosome 17, band 11.2. The syndrome is characterized by distinctive behavioral, neurocognitive, and neuropsychiatric abnormalities. This genetically mediated disorder of mental retardation prompts behavioral researchers to examine the links between genes, brain, and behavior in order to solve the gene-behavior puzzle and the genotype/phenotype correlation. In this article, the authors review literature on behavioral profile and its associated psychopathologies, cognitive profiles, multisystem abnormalities, and genetic correlates that highlight the complexities of the disorder.

The insular lobe of Reil--its anatamico-functional, behavioural and neuropsychiatric attributes in humans--a review

There is considerable clinical and experimental research to explore the anatamico-functional correlations of the limbic lobe to establish its relevance in modern neuroscience. The insula being a pivotal structure in the concept of the greater limbic lobe, we have attempted to highlight in this review the topographical anatomy and development, the remarkable heterogeneity of the insular cortical architecture, the widespread multifaceted spectrum of functional connectivity patterns and how this is translated to its behavioural specialisation in humans. The insula serves as an intergration cortex for multimodal convergence of distributed neural networks such as the somesthetic-limbic, insulo-limbic, insulo-orbito-temporal and the prefrontal-striato-pallidal-basal forebrain. This provides the conceptual framework to facilitate functional and clinical considerations relevant to the various behavioural and neuropsychiatric disorders outlined in this review. The functional role of the insula in these disorders with particular reference to the current functional neuroimaging data has been also reviewed in this article.