Ketamine in the treatment of refractory and super-refractory status epilepticus: Experience from two centres.

PURPOSE: There is insufficient evidence on the management of refractory status epilepticus (RSE) and super-RSE (SRSE). Ketamine is a N-methyl-d-aspartate receptor antagonist in the treatment of these entities. Our objectives were to study the effectiveness and safety of ketamine in the treatment of adult patients with RSE and SRSE, to determine the factors that can influence the response to ketamine, and to explore its use in patients without mechanical ventilation. METHODS: Adult patients who had received intravenous ketamine for the treatment of RSE or SRSE at Hospital Universitario Clínico San Carlos (Madrid, Spain) or Hospital Universitari Vall d'Hebron (Barcelona, Spain) from 2017 to 2023 were retrospectively analysed. RESULTS: This study included 58 adult patients, mean (standard deviation) age 60.2 (15.7) years, of whom 41 (70.7 %) were male; 33 (56.9 %) patients responded to ketamine without recurrence, with a low rate of adverse effects (8.6 %). The presence of SRSE at the time of ketamine initiation (OR 0.287, p = 0.028) and the time elapsed between status epilepticus onset and ketamine administration (OR 0.991, p = 0.034) were associated with worse response to ketamine. Patients treated without mechanical ventilation had similar rates of response without recurrence (62.5% vs 56.9 %) and lower mortality (37.5% vs 53.5 %) compared to the overall group. CONCLUSION: Ketamine is an effective drug with few adverse effects. Prompt administration should be considered in patients with RSE requiring anaesthesia, in patients with SRSE, and in patients with RSE who do not respond to standard antiseizure drugs and in whom mechanical ventilation is not advised.

Acute amnesia and seizures in a young female.

Limbic encephalitis is a condition characterised by an acute or sub-acute onset of memory disorder, associated with seizures and psychiatric manifestations. Investigations such as brain MRI usually reveal a high intensity signal in the medial temporal lobe and cerebrospinal fluid analysis shows mild pleocytosis and oligoclonal bands. It may occur in association with cancer, infection, or as an isolated clinical condition, often accompanying autoimmune disorders. Immune-mediated limbic encephalitis is now subclassified according to the presence and type of autoantibodies, which has significant consequences regarding the effectiveness of treatment and prognosis. Glutamic acid decarboxylase (GAD) is an enzyme that catalyses glutamic acid into gamma aminobutyric acid. Anti-GAD antibodies are associated with different neurological and non-neurological disorders, but only a few cases of limbic encephalitis associated with anti-GAD antibodies have been reported in the literature, most of them non-paraneoplastic. Here, we report the case of a young female patient with a medical history of psoriasis who developed an acute onset and chronic evolution of anterograde amnesia, associated with drug-resistant epilepsy. Brain MRI showed hyperintensity in the medial temporal lobes and the biochemical studies revealed intrathecal synthesis of anti-GAD antibodies. Screening tests for tumours were negative. Despite antiepileptic drugs, intravenous immunoglobulins and immunosuppressive treatment, the patient did not show clinical improvement and one year later, she continues to present refractory temporal epilepsy and cognitive deficits.

Episodes of loss of consciousness in a patient with a background of cerebral venous thrombosis.

Episodes of loss of consciousness are common, even in young, healthy people, and can sometimes represent a diagnostic challenge. The main diagnoses to consider are syncope and epileptic seizures, both of which may have similar symptomatology such as dizziness, loss of consciousness, falls, or "convulsive" phenomena. We present the case of a young male patient with a background of two venous thrombosis episodes (superior vena cava thrombosis and cerebral venous thrombosis), attributed to protein C and S deficiency and complicated by high intracranial pressure. A lumboperitoneal shunt was performed and anticoagulant therapy was initiated. He did not experience any medical problems until several years later, when he suddenly began to develop frequent, repetitive, transient episodes of dizziness, followed by loss of consciousness. Simultaneous video-EEG and ECG performed during these events showed a typical pattern normally observed during syncope. Due to the absence of changes in heart rate or blood pressure, and taking into account his medical history, intracranial hypertension was considered as a possible cause of cerebral hypoperfusion. Cerebral arteriography demonstrated chronic thrombosis of all the cerebral sinuses, and the lumbar puncture an intracranial pressure of 47 mm Hg. The lumboperitoneal shunt was replaced and the patient has since not presented with any episodes. The use of simultaneous video-EEG and ECG is a reliable and efficient approach to differentiate between syncope and seizure and in this case, was the key to finding the cause of these episodes. [Published with video sequences].