With respect to non-convulsive status epilepticus (NCSE) in the critically ill:
Change in behaviour and or mental processes from baseline associated with continuous epileptiform EEG changes but without major motor signs. NCSE comprises a group of syndromes with a wide range of response to anti-convulsants from virtually self-limiting forms to refractory forms. No universally accepted definition yet exists
Difficulties in Diagnosis:
Little agreement on diagnostic criteria, clinical forms, consequences and treatment Difficulty telling when coma is due to ictal symptomatology and differentiating it from non ictal symptoms associated with underlying pathology such as posthypoxic, metabolic or septic encephalopathies and effects of sedative drugs.
On EEG there are cross over features between epilepsy and encephalopathies which are being still standardized and the diagnosis of NCSE should not be on EEG changes alone.
Early recognition and treatment are essential to optimize response to treatment and to prevent neurological and systemic sequelae. However overdiagnosis and aggressive use of anticonvulsants may also contribute to morbidity and mortality.
Non-convulsive status epilepticus comes up often enough to merit its own little summary page.
The diagnosis of non-convulsive status epilepticus requires the following:
The difficulty in making the diagnosis is the protean nature of its manifestations, which range from confusion and delirium to unconsciousness. As there are numerous pathologies which are more common and which can present in this way, the diagnosis (by EEG confirmation) is frequently delayed.
Risk factors for non-convulsive status epilepticus are similar to the risk factors for epilepsy in general, and include:
d) Approach to management:
Chapter 49 (pp. 549) Disorders of consciousness by Balasubramanian Venkatesh
Chapter 50 (pp. 560) Status epilepticus by Helen I Opdam
Fountain, Nathan B. "Status epilepticus: risk factors and complications."Epilepsia 41.s2 (2000): S23-S30.
Meierkord, Hartmut, and Martin Holtkamp. "Non-convulsive status epilepticus in adults: clinical forms and treatment." The Lancet Neurology 6.4 (2007): 329-339.