Hypoglycemia
That transient hypoglycemia may produce a strokelike picture with hemiplegia and aphasia has
been known for years.8
These patients may be drowsy but are often alert and do not show the more
common response to hypoglycemia of confusion, diminished level of consciousness, or coma.
9
Aphasia may make the history of diabetes more difficult to discover. The syndrome has also been
reported in alcoholics with hypoglycemia.10 The pathogenesis of this focal CNS dysfunction is
unclear. Hypoglycemia is generally defined as a blood glucose level of less than 45 mg/dl in these
studies. The wide use of bedside rapid laboratory testing for glucose now makes this easily
detectable and treatable. The hemiplegia may resolve immediately with the administration of
intravenous glucose but resolution over a hours is also reported.11
Mass lesions
Subdural hematoma, cerebral abscess, primary CNS tumors, and metastatic tumors are among the
clinical conditions simulating stroke in the studies cited above. The typical clinical presentation of a
slowly increasing mass is a progressive syndrome; an abrupt onset of symptoms of these masses
seems counter-intuitive. A review of patients with brain tumors presenting to an ED showed that
6% of patients had symptoms that were of less than one day’s duration; it was thought that these
patients with brief symptom duration might reflect a sub-population who suffer acute deterioration
from hemorrhage into the tumor or who develop obstructive hydrocephalus.12 Secondary effects of
mass or edema on cerebral vasculature have been identified as possible causes of abrupt onset of
seizures as well. Chronic subdural hematoma has been frequently reported as a cause of stroke and
TIA-like symptoms.
13
Seizures and Postictal States
Every study identifying stroke mimics identifies seizures and post-seizure events as common causes
of stroke-like conditions. Traditional thought is that these postictal symptoms are manifestations of
seizure-induced alterations in neuronal function that are reversible; structural neuronal alterations
are not present. The postictal weakness or Todd’s paralysis usually follows partial motor seizures
but may follow generalized seizures as well. Duration is usually brief but may last 48 hours.14 Rare
inhibitory seizures with extremity weakness as a manifestation of the seizure event have been
reported as well.14 Seizures may also present as a complication of acute stroke or develop in a
patient with a history of stroke.15 Most studies have identified postictal states indirectly after further
seizures were observed or additional history was obtained that suggested a history of seizure
disorder.
Migraine mimicking stroke
Migraine may actually precipitate a stroke, but there is also a variant of migraine, hemiplegic
migraine, where unilateral hemiparesis outlasts the headache. This is difficult if not impossible to
diagnose correctly at first presentation when it must be regarded as a diagnosis of exclusion; only
with recurrent, stereotypic attacks can this be suspected. Cases with alternating hemiplegia have