Sudden unexpected death in epilepsy: a local audit.

Sudden unexpected death in epilepsy (SUDE) remains an under-investigated area. Little progress has been made in prospective evaluation of its incidence and causes. We report an audit of Cardiff Epilepsy Unit data that identified 14 cases of SUDE within a time period of 7000 patient-treatment years. These data suggest that SUDE occurs in 1 in 500 of our patients per year. Males were affected twice as often as females. The mean age of affected patients was 35 years, and most were in the 20-40 year age bracket. Eleven had epilepsy for more than 6 years, 12 were taking one or two antiepileptic drugs, and nine had been experiencing four or fewer seizures per month. Ten patients had idiopathic generalized seizures, and only one patient did not experience tonic-clonic seizures. Antiepileptic drug usage favoured carbamazepine. Most patients were not living alone but 11 of 14 (79%) were either unmarried, separated or widowed. In comparison with other patients attending the Epilepsy Unit (more than 1820 patients), SUDE patients were significantly (chi 2 < 0.05) more likely to be male, to have idiopathic generalized tonic-clonic seizures, or to be taking carbamazepine (monotherapy or in combination with another drug). There were no statistically significant differences in age, duration of epilepsy, number of drugs, or seizure frequency between the SUDE patients and our other patients. Correct case identification, and controlled, prospective, ante-mortem studies are needed so that the true incidence, associated risk factors and causes of sudden unexpected death in epilepsy can be accurately ascertained.

Sudden unexpected death in epilepsy: is carbamazepine implicated?

Sudden unexpected death in epilepsy (SUDEP) has been recognised for centuries. The precise frequency of occurrence is not well defined. Education of medical professionals is needed, so that death certificates and coronial inquests may appropriately, correctly and consistently record SUDEP as the case of death. Correct identification will then allow further investigation of this misunderstood, and often ignored, epilepsy complication. SUDEP incidence may be increasing, either as a result of increased recognition, or possibly due to a real increase in incidence. All currently available antiepileptic drugs (AEDs) have been associated with SUDEP, and current opinion assumes that the relative proportion of patients suffering SUDEP is representative of average AED usage type for a particular time and locality, however, recently analysed data suggest a strong bias towards carbamazepine. A review of Cardiff Epilepsy Unit data shows that carbamazepine was disproportionately represented in patients suffering SUDEP. In this series, 11 of the 14 SUDEP patients were taking carbamazepine at the time of death. This was calculated as 79% of all patients, compared to average carbamazepine usage by all other Cardiff Epilepsy Unit patients of 38%. The data also indicate that one patient was not taking any drug therapy, and died during his first seizure, reducing the number of evaluable 'drug usage' patients to 13, and increasing the proportion taking carbamazepine at the time of death to 85%, (P < 0.01). Possible mechanisms include carbamazepine induced lengthening of the ECG Q-T interval combined with a mild pro-arrhythmic effect of epileptic seizure discharges, and consequent transient cardiac instability leading to arrhythmic death. Or alternatively, excessive post-seizure brainstem inhibition might result in blunting or transient abolition of central hypoxic and hypercarbic respiratory drive, with consequent post-ictal respiratory arrest, subsequent exacerbation of hypoxia, further cardiac destabilisation and death due to hypoxia/failed re-establishment of respiration and terminal cardiac arrhythmia. Current knowledge about SUDEP remains poor. Education is needed so that case ascertainment can be correctly documented. Delineation of the precise mechanisms involved should lead to definitive prevention strategies. Evaluation of carbamazepine as a significant causative factor in SUDEP is also needed.

Caesarean section in Christchurch.

Base hospital caesarean section rates in Christchurch have risen from 4.1% in 1967 to 14.1% in 1982. However, the Christchurch district caesarean section rate for 1982 was only 9.6%. Analysis of the indications for caesarean section according to the year showed that most indications have increased in frequency and that between 1977 and 1982 this increase was highly significant for failure to progress and fetal distress. Analysis of the indications for caesarean section according to the type of antenatal booking revealed that in 1982 private patients underwent caesarean section more frequently than clinic patients and that they were more likely to have the caesarean section for failure to progress or fetal distress. Emergency transfer patients had an even higher primary caesarean section rate for most indications.

Lamotrigine as an add-on drug in the management of Lennox-Gastaut syndrome.

We report our experience with lamotrigine add-on therapy in the treatment of 11 patients with Lennox-Gastaut syndrome. Lamotrigine is a novel antiepileptic drug, chemically unrelated to the major anticonvulsants in current use. Ten patients experienced a > 50% reduction in seizure frequency, 1 patient experienced no change in seizure frequency. All patients tolerated lamotrigine satisfactorily and no side-effects were reported.

Impairment of high-contrast visual acuity in Parkinson's disease.

Several studies have shown that the visual system is affected in Parkinson's disease (PD) with reduced contrast sensitivity, low-contrast acuity, and flicker sensitivity, as well as altered electroretinograms (ERGs) and pattern visual evoked potentials (VEPs). Apparently, however, no study has yet specifically determined whether visual acuity to high-contrast stimuli is impaired in PD. Visual acuity was measured in a group of 16 patients with PD, both on and off drugs (for 24 h), and 16 age- and sex-matched normal control subjects. Acuity was impaired in the PD group both on standard Snellen chart and on a screen in a computerized test of visual resolution. The degree of impairment was 24 and 25%, respectively, in the two tests. The PD patients had marginally better acuity on both tests while receiving drugs, but the differences were not significant. The difference between the two groups was consistent with impaired resolution and could not be accounted for by any perceptual dysfunction that may also have been present in the PD group. Conversely, however, impaired acuity may be implicated in studies that have reported mild deficits of visuospatial/visuoperceptual function in PD. Reduced acuity appears to be a subtle sequela of dopaminergic deficiency in the visual system.