Medicine (Austin & Northern Health) - Research Publications

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    Tonic seizures of Lennox-Gastaut syndrome: Periictal single-photon emission computed tomography suggests a corticopontine network
    Intusoma, U ; Abbott, DF ; Masterton, RAJ ; Stagnitti, MR ; Newton, MR ; Jackson, GD ; Freeman, JL ; Harvey, AS ; Archer, JS (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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    Psychological trajectories in the year after a newly diagnosed seizure
    Velissaris, SL ; Saling, MM ; Newton, MR ; Berkovic, SF ; Wilson, SJ (WILEY-BLACKWELL, 2012-10)
    PURPOSE: Underdiagnosed depression and anxiety are well-recognized issues in chronic epilepsy, but the evolution of these symptoms after diagnosis is not well understood. We aimed to identify mood trajectories after a first seizure, and to examine factors impacting these trajectories. METHODS: Seventy-four patients were evaluated at 1, 3, and 12 months with (1) the Hospital Anxiety and Depression Scale, and (2) a semistructured interview assessing patients' initial psychological reaction to the seizure at 1 month (limited vs. pervasive loss of control). The SAS Institute's TRAJ data modelling procedure was employed to delineate trajectories. KEY FINDINGS: Two depression and three anxiety trajectories were identified, with significant overlap. The majority of patients (≈ 74%) followed a trajectory with low depression throughout the study, and either low or moderate anxiety. A minority followed trajectories with high depression and anxiety from diagnosis (≈ 16%). Patients with high levels of distress were adversely affected by seizure recurrence and antiepileptic drugs (AEDs), whereas those with low levels were not. Trajectories were predicted by the patient's sense of loss of control early after diagnosis and were weakly related to demographic and medical variables (age, gender, education, relationship status, psychiatric history, and prior epileptic events). SIGNIFICANCE: Methods that account for heterogeneity in patient responses are critical for developing a clinically relevant understanding of adjustment after a newly diagnosed seizure. Most patients appear to be resilient in the face of early seizures, whereas those at risk of longer-term psychological difficulties may be evident from diagnosis. Early screening for depression and anxiety is warranted.