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Background The hippocampus has for long been known for its ability to form new, declarative memory. However, emerging findings across conditions in the psychosis spectrum also implicate its role in emotional regulation. Systematic reviews have demonstrated consistent volume atrophic changes in the hippocampus. The aim of the systematic review and metanalysis which will follow from this protocol will be to investigate the volume-based neuroimaging findings across each of the subfields of the hippocampus in psychosis independent of diagnosis. Methods Volume changes across subfields of the hippocampus in psychotic illnesses will be assessed by systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). MRI neuroimaging studies of patients with a definitive diagnosis of psychosis (including brief pre-diagnostic states) will be included. Studies lacking adequate controls, illicit drug use, medical psychosis, history of other significant psychiatric comorbidities, or emphasis on age groups above 65 or below 16 will be excluded. Subfields investigated will include the CA1, CA2/3, CA4, subiculum, presubiculum, parasubiculum, dentate gyrus, stratum, molecular layer, granular cell layer, entorhinal cortex, and fimbria. Two people will independently screen abstracts from the output of the search to select suitable studies. This will be followed by the two reviewers performing a full-text review of the studies which were selected based on suitable abstracts. One reviewer will independently perform all the data extraction, and another reviewer will then systemically check all the extracted information using the original articles to ensure accuracy. Statistical analysis will be performed using the metafor and meta-packages in R Studio with the application of the random-effects model. Discussion This study will provide insight into the volumetric changes in psychosis of the subfields of the hippocampus, independent of diagnosis. This may shed light on the intricate neural pathology which encompasses psychosis and will open avenues for further exploration of the structures identified as potential drivers of volume change. Systematic review registration PROSPERO CRD42020199558

The often-overlooked dorsal diencephalic conduction system (DDCS) is a highly conserved pathway linking the basal forebrain and the monoaminergic brainstem. It consists of three key structures; the stria medullaris, the habenula and the fasciculus retroflexus. The first component of the DDCS, the stria medullaris, is a discrete bilateral tract composed of fibers from the basal forebrain that terminate in the triangular eminence of the stalk of the pineal gland, known as the habenula. The habenula acts as a relay hub where incoming signals from the stria medullaris are processed and subsequently relayed to the midbrain and hindbrain monoaminergic nuclei through the fasciculus retroflexus. As a result of its wide-ranging connections, the DDCS has recently been implicated in a wide range of behaviors related to reward processing, aversion and motivation. As such, an understanding of the structure and connections of the DDCS may help illuminate the pathophysiology of neuropsychiatric disorders such as depression, addiction and pain. This is the first review of all three components of the DDCS, the stria medullaris, the habenula and the fasciculus retroflexus, with particular focus on their anatomy, function and development.

Emerging evidence suggests that methadone has a specific role in the management of treatment resistant cancer-related pain.ObjectivesTo investigate the utilisation pattern, safety and efficacy of methadone prescribed as an analgesic for the management of complex cancer-related pain in an acute hospital inpatient setting.MethodsA retrospective longitudinal observational study of patients prescribed methadone as an analgesic between April 2020 and July 2021 was performed.Changes in coprescribed baseline opioid, use of breakthrough opioid analgesic, patient rated pain scores and adverse side effects were analysed.Results16 patients with complex cancer-related treatment resistant pain who were prescribed methadone were included in the study. Of the 16 patients, 14 patients had metastatic disease. Pain was classified in 14 patients as mixed nociceptive-neuropathic and in 2 patients as neuropathic. 13 patients were coprescribed methadone with a pre-established opioid. Methadone was associated with a statistically significant decrease in both opioid breakthrough analgesic by 61%±28% (pConclusionMethadone appears to have a specific role in the management of complex cancer pain, neuropathic pain, opioid-tolerance and opioid-induced hyperalgesia, which may be attributable to N-methyl-D-aspartate receptor antagonism.

Although intrathecal pumps may lead to spinal symptoms that are likely related to the pump itself, the case presented herein underscores the importance of casting a broad differential diagnosis at the time of initial presentation., Although intrathecal pumps may lead to spinal symptoms that are likely related to the pump itself, the case presented herein underscores the importance of casting a broad differential diagnosis at the time of initial presentation. ​

Medial temporal lobe structures have long been implicated in the pathogenesis of major depressive disorder. Although findings of smaller hippocampal and amygdalar volumes are common, inconsistencies remain in the literature. In this targeted review, we examine recent and significant neuroimaging papers examining the volumes of these structures in major depressive disorder. A targeted PubMed/Google Scholar search was undertaken focusing on volumetric neuroimaging studies of the hippocampus and amygdala in major depressive disorder. Where possible, mean volumes and accompanying standard deviations were extracted allowing computation of Cohen’s ds effect sizes. Although not a meta-analysis, this allows a broad comparison of volume changes across studies. Thirty-nine studies in total were assessed. Hippocampal substructures and amygdale substructures were investigated in 11 and 2 studies, respectively. The hippocampus was more consistently smaller than the amygdala across studies, which is reflected in the larger cumulative difference in volume found with the Cohen’s ds calculations. The left and right hippocampi were, respectively, 92% and 91.3% of the volume found in controls, and the left and right amygdalae were, respectively, 94.8% and 92.6% of the volume of controls across all included studies. The role of stress in temporal lobe structure volume reduction in major depressive disorder is discussed.

Reclining on the lyra of the fornix, the dorsal hippocampal commissure (DHC) facilitates communication between the left and right hippocampi. Despite being a key commissural fiber bundle of the hippocampus, the DHC remains relatively underexplored in humans. Using high-resolution T1 and T2 magnetic resonance imaging in conjunction with High Angular Resolution Diffusion Imaging and Constrained Spherical Deconvolution tractography, we investigated if there are differences between the DHC of a sample of 54 healthy controls and 38 patients diagnosed with Major Depressive Disorder (MDD). After isolating the DHC using an anatomically derived protocol, segmented volumes of the left and right temporal pole, amygdala, hippocampus and parahippocampal gyrus extracted. In both controls and MDD patients, DHC fibers were spread across each of these four regions, with the parahippocampal gyri contributing the most to the volume of this white matter tract. Furthermore, diffusion metrics showed no effect of aging or sex on the integrity of the DHC in either group. This study is the first to investigate the DHC in MDD and the first to demonstrate that the DHC connects with the amygdala and temporal pole on both sides of the brain. Our data shows that the human DHC, rather than simply connecting the left and right hippocampi, allows connections between each hippocampus and the contralateral temporal pole, amygdala and parahippocampal gyrus. This suggests that the human temporal lobe, and the parahippocampal gyrus, may exert more influence on the contralateral limbic system via the DHC than previously thought.

The thalamocingulate tract is a key component of the Papez circuit that connects the anterior thalamic nucleus (ATN) to the cingulum bundle. While the other white matter connections, consisting of the fornix, cingulum bundle and mammillothalamic tract, were well defined in Papez's original 1937 paper, the anatomy of the thalamocingulate pathway was mentioned only in passing. Subsequent research has been unable to clarify the precise anatomical trajectory of this tract. In particular, the site of thalamocingulate tract interactions with the cingulum bundle have been inconsistently reported. This review aims to synthesize research on this least studied component of the Papez circuit. A systemic approach to reviewing historical anatomical dissection and neuronal tracing studies as well as contemporary diffusion magnetic resonance imaging studies of the thalamocingulate tract was undertaken across species. We found that although inconsistent, prior research broadly encompasses two differing descriptions of how the ATN interfaces with the cingulum after passing laterally through the anterior limb of the internal capsule. The first group of studies show that the pathway turns medially and rostrally and passes to the anterior cingulate region (Brodmann areas 24, 33, and 32) only. A second group suggests that the thalamocingulate tract interfaces with both the anterior and posterior cingulate (Brodmann areas 23 and 31) and retrosplenial region (Brodmann area 29). We discuss potential reasons for these discrepancies such as altering methodologies and species differences. We also discuss how these inconsistencies may be resolved in further research with refinements of terminology for the cingulate cortex and the thalamocingulate tract. Understanding the precise anatomical course of the last remaining unresolved final white matter tract in the Papez circuit may facilitate accurate investigation of the role of the complete Papez circuit in emotion and memory.

The Stria medullaris (SM) Thalami is a discrete white matter tract that directly connects frontolimbic areas to the habenula, allowing the forebrain to influence midbrain monoaminergic output. Habenular dysfunction has been shown in various neuropsychiatric conditions. However, there exists a paucity of research into the habenula’s principal afferent tract, the SM. Diffusion-weighted tractography may provide insights into the properties of the SM in vivo, opening up investigation of this tract in conditions of monoamine dysregulation such as depression, schizophrenia, addiction and pain. We present a reliable method for reconstructing the SM using diffusion-weighted imaging, and examine the effects of age and gender on tract diffusion metrics. We also investigate reproducibility of the method through inter-rater comparisons. In consultation with neuroanatomists, a Boolean logic gate protocol was developed for use in ExploreDTI to extract the SM from constrained spherical deconvolution based whole brain tractography. Particular emphasis was placed on the reproducibility of the tract, attention to crossing white matter tract proximity and anatomical consistency of anterior and posterior boundaries. The anterior commissure, pineal gland and mid point of the thalamus were defined as anatomical fixed points used for reconstruction. Fifty subjects were scanned using High Angular Resolution Diffusion Imaging (HARDI; 61 directions, b-value 1500 mm3). Following constrained spherical deconvolution whole brain tractography, two independent raters isolated the SM. Each output was checked, examined and cleaned for extraneous streamlines inconsistent with known anatomy of the tract by the rater and a neuroanatomist. A second neuroanatomist assessed tracts for face validity. The SM was reconstructed with excellent inter-rater reliability for dimensions and diffusion metrics. Gender had no effect on the dimensions or diffusion metrics, however radial diffusivity (RD) showed a positive correlation with age. Reliable identification and quantification of diffusion metrics of the SM invites further exploration of this key habenula linked structure in neuropsychiatric disorders such as depression, anxiety, chronic pain and addiction. The accurate anatomical localization of the SM may also aid preoperative stereotactic localization of the tract for deep brain stimulation (DBS) treatment.

Cancer is the second most significant cause of morbidity and mortality worldwide. While surgery is the primary treatment form most cancers, the perioperative period and surgical stress may cause an increased propensity for loco-regional or distant metastasis. There is perhaps a signal, from in vitro, animal model laboratory studies, and retrospective clinical studies, which collectively suggest a possible effect of various anesthetic agents and techniques on tumor metastasis and survival of minimal residual cancer. Prospective randomized control trials are needed in order to truly evaluate any effect anesthesia may have on the metastatic tendency of various tumors.

A 31-year-old male patient with chronic constipation of unknown aetiology presented emergently with worsening nausea, vomiting and abdominal distension of one week duration. On examination, his abdomen was distended with minimal tenderness. A plain film of the abdomen demonstrated severe faecal loading. The patient was haemodynamically unstable on admission and appeared sick. An urgent CT abdomen and pelvis was conducted showing extensive rectal dilatation and associated proximal colonic stercoral perforation. The patient proceeded straight to theatre for laparotomy as his general condition was deteriorating rapidly. On transfer to the operating table, the patient suffered cardiopulmonary arrest. Resuscitation was immediately commenced. Abdominal compartment syndrome was suspected. Cardiac output was re-established following a midline laparotomy which acted relieve the abdominal pressure. The rectosigmoid faecal content was decompressed via an enterotomy. The perforated segment of transverse colon was resected and an end colostomy fashioned. A year later, the continuity of the bowel was re-established.

Mortality among cancer patients is more commonly due to the effects of metastasis and recurrence as opposed to the primary tumour. Various perioperative factors have been implicated in tumour growth, including anesthetic agents and analgesia techniques. In this narrative review, we integrate this information to present a summary of the best available evidence to guide the conduct of anesthesia for primary cancer surgery.We conducted a search of the PubMed database up to May 31, 2015 to identify relevant literature using the search terms "anesthesia and metastases", "anesthetic drugs and cancer", "volatile anesthetic agents and cancer", and "anesthetic technique and cancer".There is conflicting evidence regarding volatile agents; however, the majority of studies are in vitro, suggesting that these agents are associated with enhanced expression of tumourigenic markers as well as both proliferation and migration of cancer cells. Nitrous oxide has not been shown to have any effect on cancer recurrence. Local anesthetic agents may reduce the incidence of cancer recurrence through systemic anti-inflammatory action in addition to direct effects on the proliferation and migration of cancer cells. Nonsteroidal anti-inflammatory drugs affect cancer cells via inhibition of cyclooxygenase 2 (COX-2), which leads to reduced resistance of the cancer cell to apoptosis and reduced production of prostaglandins by cancer cells. Nonsteroidal anti-inflammatory drugs also suppress the cancer cell growth cycle through effects independent of COX-2 inhibition. Opioids have been shown to inhibit the function of natural killer cells and to stimulate cancer cell proliferation through effects on angiogenesis and tumour cell signalling pathways. Supplemental oxygen at the time of surgery has a proangiogenic effect on micrometastases, while the use of perioperative dexamethasone does not affect overall rates of cancer survival.Current laboratory research suggests that perioperative interventions may impact recurrence or metastasis through effects on cancer cell signalling, the immune response, or modulation of the neuroendocrine stress response. Further evidence is awaited from prospective randomized-controlled trials. Meanwhile, with limited data upon which to make strong recommendations, anesthesiologists should seek optimal anesthesia and analgesia for their patients based on individual risk-benefit analysis and best available evidence on outcomes other than cancer recurrence.

Pre-eclampsia is a multisystem disorder with incidence rates ranging from 2% to 5%. Hyponatraemia is a rare complication of pre-eclampsia. A 41-year-old, para 0+1 in vitro fertilisation monochorionic diamniotic triplet pregnancy woman presented at 25 weeks with dyspnoea and general malaise. Her antenatal course was complicated by the diagnosis of intrauterine growth restriction in triplet one at 27 weeks of gestation. At 27+3 weeks gestation, she was diagnosed as having pre-eclampsia. Subsequent biochemical analysis demonstrated hyponatraemia with serum sodium falling steadily to 117 mmol/L over the next 19 days. She was admitted to intensive care unit for stabilisation of fulminant pre-eclampsia and severe hyponatraemia at 30+5 weeks of gestation. Hypertonic saline and intravenous labetolol were administered prior to delivery by caesarean section. She recovered well postdelivery with stabilisation of her blood pressure and normalisation of her sodium level to 135 mmol/L. Awareness and frequent monitoring of hyponatraemia should become an integral part of monitoring women with pre-eclampsia.