Early development of structural networks and the impact of prematurity on brain connectivity.

Preterm infants are at high risk of neurodevelopmental impairment, which may be due to altered development of brain connectivity. We aimed to (i) assess structural brain development from 25 to 45 weeks gestational age (GA) using graph theoretical approaches and (ii) test the hypothesis that preterm birth results in altered white matter network topology. Sixty-five infants underwent MRI between 25+3 and 45+6 weeks GA. Structural networks were constructed using constrained spherical deconvolution tractography and were weighted by measures of white matter microstructure (fractional anisotropy, neurite density and orientation dispersion index). We observed regional differences in brain maturation, with connections to and from deep grey matter showing most rapid developmental changes during this period. Intra-frontal, frontal to cingulate, frontal to caudate and inter-hemispheric connections matured more slowly. We demonstrated a core of key connections that was not affected by GA at birth. However, local connectivity involving thalamus, cerebellum, superior frontal lobe, cingulate gyrus and short range cortico-cortical connections was related to the degree of prematurity and contributed to altered global topology of the structural brain network. The relative preservation of core connections at the expense of local connections may support more effective use of impaired white matter reserve following preterm birth.

Acute pylephlebitis secondary to perforated sigmoid diverticulitis: A case report.

Pylephlebitis is defined as the development of portal venous thrombosis secondary to intra-abdominal infection or inflammation. We present the case of a 69-year-old male with pylephlebitis who attended the Emergency Department with nonspecific abdominal pain, rigors and deranged liver function tests. After an initial negative ultrasound study, computed tomography (CT) scanning demonstrated perforated diverticulitis with an associated thrombus within the portal venous system. Prompt imaging coupled with a high index of clinical suspicion helps in identifying this condition early, significantly reducing morbidity and mortality rates. This case emphasizes the importance of careful evaluation of the portal venous system in cases of intra-abdominal sepsis to exclude this rare, and sometimes fatal, condition.

Prostate cancer and sarcoma: Challenges of synchronous malignancies.

Synchronous primary malignancies are a rare finding which can be difficult to diagnose. We present the case of a 57-year-old patient with a high prostate specific antigen who was found to have prostate cancer on subsequent magnetic resonance imaging. A skeletal metastasis was also identified at the time, although no osteoblastic activity or sclerosis was identified on skeletal scintigraphy or computed tomography, respectively. The patient was started on hormonal therapy and follow-up imaging revealed the prostate cancer to have reduced in volume. Despite this, the skeletal metastasis appeared unchanged on magnetic resonance imaging and an F18-choline positron emission tomography study was negative. A computed tomography guided bone biopsy was organized and this demonstrated metastatic leiomyosarcoma. As a result, an F18-fluorodeoxyglucose positron emission tomography study was performed to find the primary lesion which demonstrated a large malignant tumor within the calf. Subsequently, the patient was referred to a tertiary sarcoma unit. This case highlights the challenges involved in diagnosing and managing synchronous malignancies.

Gallstone ileus with an enterovaginal fistula: a rare complication of pelvic radiotherapy.

Gallstone ileus is a rare cause of small bowel obstruction. Chronic gallstone irritation can lead to the formation of a cholecystoduodenal fistula, with gallstone impaction typically in the terminal ileum. Rarely gallstones can become impacted in other structures such as the colon or can even erode through the bowel. We present an unusual case of a gallstone ileus which resulted in the formation of an enterovaginal fistula, secondary to previous pelvic radiotherapy. Our case highlights the importance of considering fistula formation as a late complication of radiotherapy and how this can alter expected features of other pathologies, such as a gallstone ileus.