A 21-year-old man with a prior history of seizures is brought to the emergency department by ambulance during a tonic-clonic seizure. His mother, who accompanied him, found him on the floor seizing. She says that he has not been compliant with his medications. The patient received intravenous lorazepam, thiamine, and glucose en route but continued seizing. In the emergency department, he is unresponsive and cyanotic. His blood pressure is 96/54 mm Hg and his pulse is 152/min and regular. His pupils are mid-size and reactive to light. Clonic jerks of all extremities are observed. The patient is at highest risk for which of the following?
This patient presents with status epilepticus in the setting of seizure disorder and noncompliance with antiepileptic therapy. Approximately 30% of patients with epilepsy will have status epilepticus, especially those who are noncompliant with medical therapy. Status epilepticus has been defined historically as a single seizure lasting >30 minutes. However, recent studies suggest that a brain that has seized for >5 minutes is at increased risk of developing permanent injury due to excitatory cytotoxicity.
Cortical laminar necrosis is the hallmark of prolonged seizures and can lead to persistent neurologic deficits and recurrent seizures. Magnetic resonance imaging of the brain will generally show evidence of cortical hyperintensity on diffusion-weighted imaging suggesting infarction. The definition of status epilepticus has therefore been amended to be any single seizure lasting >5 minutes or a cluster of seizures with the patient not recovering a normal mental status in between. The exact duration of this patient's seizures is unknown. However, given that they began at home and continue in the emergency department, it can be assumed that he has been seizing for >5 minutes, consistent with status epilepticus.
(Choice A) Cerebellar atrophy is not considered a sequelae of prolonged seizures as the cortex is generally the site for seizure activity in the brain and is therefore more likely to be affected by excitatory cytotoxicity. Cerebellar atrophy can be caused by chronic use of certain antiepileptic drugs (eg, phenytoin) and heavy alcohol use.
(Choice C) Persistent seizure activity may cause increases in intracranial pressure but will not lead to obstructive hydrocephalus.
(Choice D) Persistent seizure activity is more likely to lead to excitatory cytotoxicity affecting the cortex as opposed to the basal ganglia structures. Therefore, this patient is unlikely to develop Parkinson's syndrome.
(Choice E) Persistent seizure activity may cause increased intracranial pressure and could lead to an intracranial hemorrhage. However, cortical laminar necrosis secondary to excitatory cytotoxicity is more likely.
Educational objective:
Recent studies have suggested that a brain that has seized for >5 minutes (status epilepticus) is at increased risk of developing permanent injury due to excitatory cytotoxicity. Cortical laminar necrosis is the hallmark of prolonged seizures and can lead to persistent neurologic deficits and recurrent seizures.