Neuronal stability within the complex circuits of the CNS exists in a balance between excitatory and inhibitory influences.6,11 In general, excitatory glutamatergic activity is responsible for the initiation and spread of seizure activity and inhibitory GABAergic activity is responsible for its suppression. Thus, dysfunction in glutamatergic and/or GABAergic neurotransmission presents the chemical basis for seizures.
Seizure symptoms vary according to the anatomical location of seizure activity and may include prominent motor symptoms, loss of consciousness, paroxysmal alterations in sensory functions, and changes in higher order functions (e.g., emotion, memory, language, insight).20,21 Focal seizures result from abnormal activity within a finite area of the brain. Primary generalized seizures reflect abnormal activity from a central area.
Focal seizure without altered awareness, typically results from abnormal activity in the motor, sensory, or visual cortex resulting in involuntary/repetitive movement, paresthesia, and flashing lights, respectively.6,11,20,21 Focal seizure with altered awareness typically results from abnormal activity within the temporal lobe of the cortex characterized by an aura, involuntary/repetitive movements (lip smacking, hand wringing), and impaired memory.6,11,20,21
Primary generalized seizures emanate from central brain regions and spread rapidly to both hemispheres of the cortex and include absence seizure (brief loss of consciousness, blank stare, occasional motor symptoms such as eye blinking or lip smacking, but without an aura); myoclonic seizure (brief individual or generalized muscle contractions); and tonic-clonic seizure (muscle contractions followed by shaking movement of the body).6,11,20,21
Drugs of choice for the long-term treatment of seizures vary (Table 5).2,6,11,20,21 For partial or focal seizures high-voltage-activated calcium channel inhibitors may be prescribed. Sodium channel inhibitors and benzodiazepine GABAA-receptor modulators are effective for the treatment of both focal as well as tonic-clonic seizures. Patients with complex partial or absence seizures are prescribed low-threshold T-type calcium channel inhibitors.
When providing oral healthcare to patients with seizure disorders, the goals are to develop and implement timely preventive and therapeutic strategies. Confirm adherence to medication regimen. Perioperatively monitor to confirm ongoing alertness and other symptoms appropriate for the anticipated seizure disorder (predicated on the medical/drug history of the patient) and be prepared to respond to acute seizure-related events.