Long term monitoring in refractory epilepsy: the Gowers Unit experience.

INTRODUCTION: Guidelines from the National Institute for Health and Clinical Excellence (NICE) and the International League Against Epilepsy recommend long term EEG monitoring (LTM) in patients for whom seizure or syndrome type is unclear, and in patients for whom it is proving difficult to differentiate between epilepsy and non-epileptic attack disorder (NEAD). The purpose of this study was to evaluate this recommended use of LTM in the setting of an epilepsy tertiary referral unit. METHODS: This study reviewed the case notes of all admissions to the Sir William Gowers Unit at the National Society for Epilepsy in the years 2004 and 2005. A record was made of the type, duration and result of all LTM performed both prior to and during the admission. Pre- and post-admission diagnoses were compared, and patients were divided according to whether LTM had resulted in a change in diagnosis, refinement in diagnosis or no change in diagnosis. The distinction between change and a refinement in the diagnosis was made on the basis of whether or not this alteration resulted in a change in management. RESULTS: 612 patients were admitted during 2004 and 2005, 230 of whom were referred for diagnostic clarification. Of these, LTM was primarily responsible for a change in diagnosis in 133 (58%) and a refinement of diagnosis in 29 (13%). In 65 (29%) patients the diagnosis remained the same after LTM. In those patients in whom there was a change in diagnosis, the most common change was in distinguishing epilepsy from NEAD in 73 (55%) and in distinguishing between focal and generalised epilepsy in 47 (35%). LTM was particularly helpful in differentiating frontal lobe seizures from generalised seizures and non-epileptic attacks. Inpatient ambulatory EEG proved as effective as video telemetry in helping to distinguish between NEAD, focal and generalised epilepsy. DISCUSSION: The study revealed that LTM led to an alteration in the diagnosis of 71% of patients referred to a tertiary centre for diagnostic clarification of possible epilepsy. Although LTM is relatively expensive, time consuming and of limited availability, this needs to be balanced against the considerable financial and social cost of misdiagnosed and uncontrolled seizures. This service evaluation supports the use of performing LTM (either video or ambulatory) in a specialist setting in patients who present diagnostic difficulty.

Cortical excitability predicts seizures in acutely drug-reduced temporal lobe epilepsy patients.

OBJECTIVE: To test the hypothesis that cortical excitability changes prior to seizures, using transcranial magnetic brain stimulation (TMS). METHODS: We studied 18 patients with unilateral temporal lobe epilepsy (TLE) twice using TMS: prior to (day 1) and following (day 3) reduction of antiepileptic drugs in a monitored inpatient setting. Short-latency intracortical inhibition (SICI) and intracortical facilitation (ICF) were measured. Time since most recent seizure prior to day 1, and time until next seizure after day 3, were recorded. RESULTS: On day 1, prior to antiepileptic drug withdrawal, there were no correlations with recent or next seizures. On day 3, patients who had seizures in the subsequent 48 hours had weaker SICI and ICF in the hemisphere ipsilateral to seizure onset, vs patients who did not have seizures in the next 48 hours (p = 0.033). Additionally on day 3, there was a strong correlation between the difference between ICF and SICI in the ipsilateral hemisphere and time to next seizure (p < 0.001). CONCLUSIONS: Change in cortical excitability, measured with transcranial magnetic brain stimulation, may reflect a long-lasting and widespread pre-ictal state.

Misdiagnosis of seizures: insulinoma presenting as adult-onset seizure disorder.

Once diagnosed with a refractory seizure disorder, patients often receive aggressive and escalating pharmacotherapy. However, a significant proportion of patients referred to neurologists do not have epilepsy. Toxic and metabolic causes of seizures should always be considered as they are potentially curable, and may be fatal if untreated. The following case report highlights the need for careful reassessment of all seizures that are atypical and refractory to medication.

Neurophysiological prediction of outcome in obstetric lesions of the brachial plexus.

Seventy-three children with slow recovery after obstetric lesion of the brachial plexus (biceps function returning after 3 months of age) and with relatively favourable neurophysiological investigation were followed until a mean age of 4.3 years. Predictions for C6 and C7 were confirmed in 92% and 96% of the cases, respectively. Predictions for C5 were confirmed in a smaller proportion of cases (78%). The inability to record nerve action potentials for C5, and the high frequency of secondary shoulder pathology are reasons for this. In all, 33 of the 73 children came to operation for medial rotation contracture (11) or posterior subluxation/dislocation (21); there was one case operated for inferior contracture.