Although all patients with epilepsy have seizures, the converse is not necessarily true, particularly for patients with seizures from metabolic disturbances.
Metabolic disorders cause seizures in three ways:1–3
- alteration of intracellular osmolality
- depletion of substrates essential for cellular metabolism or membrane function
- intracellular accumulation of toxic substances
With the exception of certain inborn errors of metabolism, most acute metabolic derangements that present with seizures are treatable and reversible with specific interventions. Seizures due to metabolic disorders present diagnostic as well as therapeutic challenges, however. Close collaboration between the neurologist and the medical specialist is essential in the care of the patient with seizures of metabolic origin.
Because AEDs alone are generally of limited benefit, and acute metabolic derangements can be fatal if untreated, neurologists must consider this group of disorders when patients present with new-onset seizures or when patients with epilepsy have an unexplained worsening of seizure frequency or severity.95
Adapted from: Schachter SC and Lopez MR. Metabolic disorders. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;195–208.
With permission from Elsevier (www.elsevier.com).