Neuron specific enolase and status epilepticus-induced neuronal injury

Neuron specific enolase as a marker of seizure related neuronal injury

BACKGROUND

and purpose: Neuron specific enolase (NSE) is an established biomarker of neuronal damage. It is not clear how much seizures contribute to the neuronal damage, morbidity or mortality in critically ill neurology patients. The aim of this study is to determine the impact of seizures on neuronal injury in critically ill neurology patients by using neuron specific enolase as a biomarker.

MATERIAL AND METHODS

Forty patients with clinical evidence of acute central nervous system disease associated with seizures were included as critically ill neurology patients with seizures [CINPS] (age in years 38.8 ± 17.54, mean ± SD; 22 males) and 43 age and sex-matched acute central nervous system disease without seizures were recruited as critically ill neurology patients [CINP] (age in years 37.84 ± 17.38 years mean ± SD; 24 males) The serum NSE assays were performed in CINPS (within 24 h of last seizure) and in CINP using an enzyme immunoassay kit.

RESULTS

The level of serum neuron specific enolase was significantly higher in CINP with seizures compared to those without seizures. The length of ICU stay was more prolonged in those with seizures. There was a close correlation between the NSE levels and frequency of seizures. There was no significant difference in the mortality between both the groups.

CONCLUSIONS

NSE a marker of neuronal injury was elevated in patients with acute central nervous system diseases. It is significantly higher in patients with seizures in comparison to those without seizures. This warrants further studies to document aggressive treatment of seizures in acute neurologically ill patients can reduce neuronal damage.

Nonconvulsive status epilepticus: clinical features and diagnostic challenges

NCSE, once thought to be a rare disorder, should be considered in any patient presenting with an alteration in mental status of indeterminate cause. The psychiatrist needs to be aware of the different clinical characteristics of this disorder as well as similarities and differences from psychiatric disorders. A history of seizure is not necessary for the diagnosis, nor is motor activity necessarily associated with NCSE. An EEG is required to confirm the diagnosis and should be performed when possible, because early recognition and treatment may improve outcome. There is usually a good response to an intravenous benzodiazepine; when response has been delayed, other anticonvulsants have been used as adjuncts. The EEG is necessary to distinguish AS from CPS so that, when indicated, the proper long-term antiepileptic drug therapy can be started. Although NCSE has been described in the literature for many years, there is still a great need for carefully designed prospective studies to help define clear guidelines to assist in clinical and management decision making and, ultimately, to improve outcomes.

Serum neuron-specific enolase is a marker for neuronal damage following status epilepticus in the rat

We determined the serum concentrations of neuron-specific enolase (s-NSE) in rat pups of 1, 2, 3, and 4 weeks of age and in adult rats that were subjected to lithium-pilocarpine status epilepticus (SE). Damage to brain regions was rated on a scale of 0 (no damage) to 5 (> 50% cell loss). Rat pups of 1-2 weeks of age had a higher baseline s-NSE than the adults. Following SE, 1 week old rat pups had no elevation of s-NSE and no histologic evidence of damage. At older ages the increases in NSE ranged from 18.9 +/- 0.8 ng/ml in the 2 week old (vs. 11.5 +/- 0.5 control) to 35.8 +/- 2.1 ng/ml in the 3 week old (vs. 12.1 +/- 0.8 control). In the adult rats s-NSE increased from 5.4 +/- 0.4 in the control animals to 30.4 +/- 1.3 after SE. The different brain regions examined had distinctive ontogenic profiles for SE-induced damage. Elevation of s-NSE after SE correlated with overall histologic evidence for damage.