Article
Transient ischemic attack: Omen and opportunity
A transient ischemic attack (TIA) is often the precursor of stroke. As such, every TIA deserves to be taken seriously.
Partial seizure
Partial seizure produces a diverse range of stereotypical symptoms due to focal abnormal neuronal activation. The aberrant electrical firing generates positive symptoms involving the motor, sensory, or visual pathway. A history of trauma, neurosurgical intervention, central nervous system infection, stroke, or other seizure foci can suggest this diagnosis. Other prodromal clues include abdominal discomfort, sense of detachment, déjà vu , or jamais vu .26
During a seizure, there may be a progression of positive symptoms similar to what happens in migraine aura, because both represent cortical spread and depression.
Involvement of the motor pathway may produce tonic (stiffening) or clonic (twitching) movement. Other common motor abnormalities include automatisms such as lip smacking, chewing, and hand gestures (picking, fidgeting, fumbling). 27
Epileptic discharges in the sensory cortex commonly cause paresthesias or distortion of a sensory input. Visual symptoms may be more complex. In occipital epilepsy, circular phenomena with a colored pattern are common, which contrasts with the photopsia (flashes of light) or fortification (a bright zigzag of lines resembling a fort) seen in migraines. 28
Autonomic or somatosensory symptoms can also occur.
Todd paralysis, also called transient postictal paralysis, occurs in only 13% of seizures but can linger for 0.5 to 36 hours. 29,30 This weakness is most pronounced within the affected region after a partial seizure.
In general, focal seizures are often stereotyped with positive neurologic features, usually last a few minutes, and resolve fully. These episodes may cause an arrest in activity but not usually loss of consciousness unless the epileptic discharge secondarily generalizes into the adjacent hemisphere.
A common differential diagnosis encountered during an epilepsy workup is psychogenic nonepileptic seizures. Nonepileptic seizures consist of transient, abnormal movements, sensation, or cognition but lack ictal electroencephalographic changes. This is a specifically challenging patient population, with high healthcare utilization and high risk for iatrogenic harm. In addition, on average, diagnosis can take years to establish and usually requires referral to a tertiary care facility. 31,32
The big 3: Back to our patient
Our patient’s vascular risk factors, transient symptoms, and language involvement support the diagnosis of TIA. A feature that points away from the diagnosis of TIA is the gradual onset of positive neurologic symptoms. This pattern is not consistent with neuronal ischemia.
Also, our patient had a repetitive, stereotypical pattern of symptoms, which supports including partial seizures in the differential diagnosis. On the other hand, her lack of risk factors for seizure (a history of febrile seizures, developmental delay, trauma, or infection) would make this diagnosis less likely. Also pointing away from the diagnosis of seizures are her lack of typical prodromal symptoms, the length of the events, and the postevent headache.
Table 1 summarizes the clinical findings associated with TIA, migraine, and partial seizure.