Q1 Neurology St George 2002
45 yo male presents following tonic-clonic seizure. He has been having intermittent episodes of déjà vu followed by “blackouts” over last 6 mo. EEG shows PLEDs over R temporal region. Most likely diagnosis:
a)primary generalized epilepsy
b)frontal lobe epilepsy
c)TLE secondary to cavernoma
d)TLE secondary to cerebral abscess- could be, but no history to suggest infection
e)Non epileptic condition- pt has auras, excluding NESeizure
Less than one-half of epilepsy cases have an identifiable cause. It is presumed that epilepsy in most, if not all, of these other patients is genetically determined. In the remainder of patients in whom an etiology can be determined, the causes of epileptic seizures include congenital brain malformations, inborn errors of metabolism, high fevers, head trauma, brain tumors, stroke, intracranial infection, cerebral degeneration, withdrawal states, and iatrogenic drug reactions. In the elderly, vascular, degenerative, and neoplastic etiologies are more common than in younger adults and children. A higher proportion of epilepsy in children is due to congenital brain malformations than in other age groups. In young to middle-aged adults, common findings on MRI are mesial temporal sclerosis, sequelae of head injury, congenital anomalies, brain tumors, and vascular lesions. In the elderly, MRIs often reveal strokes, cerebral degeneration, or neoplasms.
The term "periodic lateralized epileptiform discharge" (PLED) was first applied in 1964 to describe periodic complexes consisting of a spike, polyspike, or sharp wave followed by a slow wave occurring every one to two seconds on the electroencephalogram (EEG). PLEDs characteristically appear over an acute, unilateral forebrain lesion. They are most frequently a sequel of cerebral infarction or tumor. PLEDs are often self-limited, resolving within a few days or weeks; in rare cases, however, they are a chronic finding on EEG. PLEDs have a high association with focal seizures.
The leading seizure type is focal motor, often as simple partial status epilepticus (epilepsia partialis continua) or as repeated focal motor seizures. In two reports, for example, partial motor status epilepticus was seen in 50 percent of cases, often leading to secondary generalization. Isolated generalized tonic-clonic seizures can also occur, frequently with bilateral PLEDs seen after diffuse hypoxic brain damage. Complex partial seizures are rarely associated with PLEDs. Complex partial seizures (previously called temporal lobe seizures or psychomotor seizures) are the most common type of seizure in epileptic adults. During the seizure patients appear to be awake but are not in contact with others in their environment and do not respond normally to instructions or questions. They often seem to stare into space and either remain motionless or engage in repetitive behaviors, called automatisms, such as facial grimacing, gesturing, chewing, lip smacking, snapping fingers, repeating words or phrases, walking, running, or undressing
Auras (simple partial seizures) — Symptoms that a patient experiences at the beginning of the seizure are referred to as the warning or aura. Auras are seizures that affect enough of the brain to cause symptoms, but not enough to interfere with consciousness. Thus, the occurrence of an aura favors the diagnosis of an epileptic seizure.