Medicine (Austin & Northern Health) - Research Publications
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ItemNo Preview AvailableA neurodevelopnnental basis for BECTS: Evidence from structural MRI(ELSEVIER SCIENCE BV, 2013-07)PURPOSE: BECTS (benign epilepsy with centro-temporal spikes) is one of the most common childhood-onset epilepsy syndromes. We investigated quantitative evidence for brain morphological variation associated with BECTS to provide insights into the neuroanatomical basis of this disorder. METHODS: Three independent BECTS groups were imaged at different stages: (a) near onset (n=16, mean age 9.3±1.6 years), (b) ~9 years after onset (n=9, mean age 15.8±2.3 years), and (c) ~15 years after onset (n=10, mean age 22.7±2.7 years). Age-matched controls were imaged with each group. Whole brain T1-weighted MRI was acquired. Voxel-based morphometry (groups a-c) and cortical thickness analyses (groups b and c) were undertaken within each group and for the groups combined. The relationship between cortical morphology and age was investigated. KEY FINDINGS: The voxel-based morphometry analysis indicated increased bilateral grey matter volume in the superior frontal gyrus, insula and right inferior frontal gyrus regions in BECTS. The magnitude of the increase lessened with age of the cases. Cortical thickness analysis revealed thicker cortex in BECTS along middle and inferior frontal gyri bilaterally, left insula and bilateral supramarginal gyrus in the 9-year-after-onset group, that normalised with age. The rate of cortical thickness changes with age were greater in BECTS cases than in controls. SIGNIFICANCE: Increased cortical gray matter associated with BECTS was found. The decreasing magnitude of the effect with increasing age parallels the natural history of the disorder. The areas affected are consistent with neurocognitive dysfunction in BECTS.
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ItemNo Preview AvailableTonic seizures of Lennox-Gastaut syndrome: Periictal single-photon emission computed tomography suggests a corticopontine network(WILEY, 2013-12)PURPOSE: Lennox-Gastaut syndrome (LGS) is a severe epileptic disorder with characteristic electroclinical features but diverse etiologies. The shared electroclinical characteristics suggest that common cerebral networks are involved in generating seizures. We sought to reveal these networks by comparing ictal and interictal single-photon emission computed tomography (SPECT). METHODS: We identified 10 ictal-interictal SPECT pairs from seven patients with LGS (median age 11 years; range 1-38) who were studied during video electroencephalography (EEG)-confirmed tonic seizures. We performed a voxel-wise comparison of ictal and interictal SPECT studies across the group. The evolution of blood flow changes was explored by examining early and late injection groups. KEY FINDINGS: Median duration of tonic seizures was 10 s (range 6-29 s), and injection latency from seizure offset was -8 to 48 s. In the early injection group (<10 s; three studies), there was hyperperfusion over pons and cerebellar hemispheres (p < 0.05 cluster corrected family wise error), and hypoperfusion bilaterally over the pericentral region, with a trend toward hyperperfusion over bilateral superior and middle frontal gyri, and lateral parietal cortex. In the late injection group, there was hyperperfusion over midline and lateral cerebellar regions, with hypoperfusion widely over bilateral frontal regions. SIGNIFICANCE: This study suggests that the tonic seizures of LGS result from activity in a network, containing bilateral frontal and parietal association areas and the pons. We postulate that tonic seizures recruit the corticoreticular system, which connects frontal attentional areas to the pontine reticular formation, and is normally responsible for postural tone and orienting behavior.
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ItemMurray Valley encephalitis: a review of clinical features, diagnosis and treatment(AUSTRALASIAN MED PUBL CO LTD, 2012-03-19)Murray Valley encephalitis virus (MVEV) is a mosquito-borne virus that is found across Australia, Papua New Guinea and Irian Jaya. MVEV is endemic to northern Australia and causes occasional outbreaks across south-eastern Australia. 2011 saw a dramatic increase in MVEV activity in endemic regions and the re-emergence of MVEV in south-eastern Australia. This followed significant regional flooding and increased numbers of the main mosquito vector, Culex annulirostris, and was evident from the widespread seroconversion of sentinel chickens, fatalities among horses and several cases in humans, resulting in at least three deaths. The last major outbreak in Australia was in 1974, during which 58 cases were identified and the mortality rate was about 20%. With the potential for a further outbreak of MVEV in the 2011-2012 summer and following autumn, we highlight the importance of this disease, its clinical characteristics and radiological and laboratory features. We present a suspected but unproven case of MVEV infection to illustrate some of the challenges in clinical management. It remains difficult to establish an early diagnosis of MVEV infection, and there is a lack of proven therapeutic options.
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ItemSuboptimal anti-epilepsy drug use is common among Indigenous patients with seizures presenting to the emergency department(ELSEVIER SCI LTD, 2012-01)We aimed to explore the causes of higher than expected rates of Indigenous emergency department (ED) seizure presentations. A questionnaire was administered to adult patients presenting with seizure to an ED in Far North Queensland. Over 15 months, among 260 presentations with seizure (22% Indigenous), 50% non-Indigenous patients, and 45% Indigenous patients completed the questionnaire. Risk factors for alcohol misuse were common in both groups (50% Indigenous, 43% non-Indigenous; p = 0.50), as were rates of reported head injury (50% Indigenous, 44% non-Indigenous; p = 0.50). However, 47% Indigenous patients, compared to 19% non-Indigenous patients (p < 0.05) reported missing anti-epileptic tablets at least twice weekly, representing clinically relevant medication non-adherence. This was the first reported seizure presentation for 12% Indigenous patients and 26% non-Indigenous patients. We conclude that among ED seizure presentations, alcohol excess and prior head injury are commonly observed, in both Indigenous and non-Indigenous patients. However, Indigenous patients have higher rates of anti-convulsant non-adherence, likely contributing to ED presentations.