The respiratory control of carbon dioxide in children and adolescents referred for treatment of psychogenic non-epileptic seizures.

Psychogenic non-epileptic seizures (PNES) are a common problem in paediatric neurology and psychiatry that can best be understood as atypical responses to threat. Threats activate the body for action by mediating increases in arousal, respiration, and motor readiness. In previous studies, a range of cardiac, endocrine, brain-based, attention-bias, and behavioral measures have been used to demonstrate increases in arousal, vigilance, and motor readiness in patients with PNES. The current study uses respiratory measures to assess both the motor readiness of the respiratory system and the respiratory regulation of CO2. Baseline respiratory rates during clinical assessment and arterial CO2 levels during the hyperventilation component of routine video electroencephalogram were documented in 60 children and adolescents referred for treatment of PNES and in 50 controls. Patients showed elevated baseline respiratory rates [t(78) = 3.34, p = .001], with 36/52 (69%) of patients [vs. 11/28 (39%) controls] falling above the 75th percentile (χ 2 = 6.7343; df = 1; p = .009). Twenty-eight (47%) of patients [vs. 4/50 (8%) controls] showed a skewed hyperventilation-challenge profile-baseline PCO2 <36 mmHg, a trough PCO2 ≤ 20 mmHg, or a final PCO2 <36 mmHg after 15 min of recovery-signaling difficulties with CO2 regulation (χ 2 = 19.77; df = 1; p < .001). Children and adolescents with PNES present in a state of readiness-for-action characterized by high arousal coupled with activation of the respiratory motor system, increases in ventilation, and a hyperventilation-challenge profile shifted downward from homeostatic range. Breathing interventions that target arousal, decrease respiratory rate, and normalize ventilation and arterial CO2 may help patients shift brain-body state and avert PNES episodes.

Etiological associations and outcome predictors of acute electroencephalography in childhood encephalitis.

OBJECTIVES: To examine EEG features in a retrospective 13-year cohort of children with encephalitis. METHODS: 354 EEGs from 119 patients during their admission were rated blind using a proforma with demonstrated inter-rater reliability (mean k=0.78). Patients belonged to 12 etiological groups that could be grouped into infectious and infection-associated (n=47), immune-mediated (n=36) and unknown (n=33). EEG features were analyzed between groups and for risk of abnormal Liverpool Outcome Score and drug resistant epilepsy (DRE) at last follow up. RESULTS: 86% children had an abnormal first EEG and 89% had at least one abnormal EEG. 55% had an abnormal outcome, and 13% had DRE after median follow-up of 7.3years (2.0-15.8years). Reactive background on first EEGs (9/11, p=0.04) and extreme spindles (4/11, p<0.001) distinguished patients with anti-N-Methyl-d-Aspartate Receptor encephalitis. Non-reactive EEG background (48% first EEGs) predicted abnormal outcome (OR 3.8, p<0.001). A shifting focal seizure pattern, seen in FIRES (4/5), anti-voltage gated potassium channel (2/3), Mycoplasma (1/10), other viral (1/10) and other unknown (1/28) encephalitis, was most predictive of DRE after multivariable analysis (OR 11.9, p<0.001). CONCLUSIONS: Non-reactive EEG background and the presence of shifting focal seizures resembling migrating partial seizures of infancy are predictors of abnormal outcome and DRE respectively in childhood encephalitis. SIGNIFICANCE: EEG is a sensitive but non-discriminatory marker of childhood encephalitis. We highlight the EEG features that predict abnormal outcome and DRE.

Reduced complications from intracranial grid insertion by using a small grid size and a precise protocol during monitoring.

BACKGROUND: A study of the risk factors associated with complications during intracranial EEG monitoring led to a change in protocol for monitoring and implantation at our centres. We conducted a study to identify any reduction in complications following the changed protocols involving the use of smaller subdural electrode arrays, continuous ICP monitoring, use of a central line, and intake of prophylactic antibiotics and dexamethasone. METHODS: We prospectively collected data on patient outcomes between 2005 and 2012 (group B) compared with patients between 1988 and 2004 (group A) before the protocol changes. RESULTS: Seventy-one patients in group A and 58 patients in group B underwent intracranial electrode implantation. Complications directly related to grids occurred in 25 % of group A vs. 8.6 % in group B (p < 0.05) and those indirectly related to grids were 11.2 % in group A vs. none in group B. The rate of transient complications requiring no treatment was 12.5 % in group A versus 1.7 % in group B. The rate of transient complications requiring treatment was 10 % in group A and 6.9 % in group B. There were two deaths in group A. The infection rate was higher in group B than group A (5.2 % vs. 2.8 %; p = 0.90). Since 2008 there have been no infective complications. Complications directly related to intracranial EEG monitoring were significantly reduced using the revised protocol (p < 0.05). Regression analysis identifying only the size of the grids (≤4 × 8 grid arrays) implanted was an independent predictor of more complications in group A (P < 0.05). CONCLUSIONS: Complication rates following intracranial implantation decreased following the use of a small grid size and adherence to a stringent protocol.

Longitudinal assessment of neuropsychologic and language function in children with benign rolandic epilepsy.

Previous studies of benign rolandic epilepsy have reported improvement in cognitive functioning over time. Their focus was the impact of paroxysmal electroencephalographic (EEG) activity on neuropsychologic function. Comprehensive longitudinal language assessment has not previously been undertaken. In a cross-sectional study, we demonstrated that some children with benign rolandic epilepsy have difficulties in verbal and visual memory and phonologic awareness. The current study evaluated a subgroup longitudinally to determine if difficulties improved. Twenty-eight patients underwent comprehensive longitudinal neuropsychologic and language assessments. The clinical features evaluated included seizure frequency, absolute age, medications, and a follow-up EEG. Differences in performance were analyzed using t-tests. Improvement in cognitive functioning, particularly in the areas of verbal memory, receptive language ability, and phonemic manipulation, was demonstrated. Visual memory and aspects of phonologic awareness showed no change. The improvements were not related to the clinical variables. It is important to recognize cognitive difficulties in children with benign rolandic epilepsy. Some difficulties can resolve; however, continued monitoring, particularly in areas of visual memory and phonologic awareness, is required.