By Alan Z. Segal, MD
Associate Professor of Clinical Neurology, Weill Cornell Medical College
Dr. Segal reports no financial relationships relevant to this field of study.
SYNOPSIS: In a large retrospective review of 2137 patients with intracerebral hemorrhage, 34 had transient symptoms that could have been misclassified as “transient ischemic attack” if brain imaging had not been performed.
SOURCE: Kumar S, et al. Transient neurological symptoms in patients with intracerebral hemorrhage. JAMA Neurol 2016; Jan. 4 [Epub ahead of print].
Transient ischemic attack (TIA) has classically been defined as having a 24-hour time limit. More recently, diffusion-weighted magnetic resonance imaging (MRI) has shown that many TIAs, much shorter in duration, show radiological evidence of permanent tissue damage. The ABCD2 score, which predicts stroke in association with TIA, identifies factors predictive of stroke such as motor or speech disturbance (as opposed to pure sensory) or longer symptom duration (> 1 hour).
In contrast to TIA, the diagnosis of intracerebral hemorrhage (ICH) is easily made on a non-contrast CT scan. This study sought to identify a subset of ICH patients for whom transient symptoms might imply a diagnosis of TIA, when imaging in fact reveals a hemorrhage. This is a retrospective analysis of hospital admissions carrying the diagnosis of ICH between 2000 and 2014 at the Beth Israel Hospital in Boston, under the direction of Dr. Louis Caplan, who has been studying ICH for decades. Out of 2137 patients with ICH, 34 had symptoms lasting less than 24 hours. There were 17 patients with sufficient data to include in the analysis. Of these, symptom duration was < 30 minutes in the majority (n = 9) and > 12 hours in only one patient. NIH Stroke Scores were all ≤ 5. The majority of patients had small hemorrhages < 30 cc (many < 10 cc), with only two having hemorrhages > 30 cc (33 cc and 40 cc) and a mean hemorrhage volume of 17 cc.
Five patients took antiplatelet therapy at home, which was not thought to affect outcome. Hypertension was determined to be the etiology in eight patients, cerebral amyloid angiopathy in two patients, coagulopathy in two, and other causes in the remainder (cavernoma, Moya-Moya, or undetermined [n = 3]).
This study emphasizes the clinical spectrum of ICH, since these patients with small-volume ICH did not present with the classical clinical picture of headache, vomiting, and progressive neurological signs. As the authors noted, this study may greatly underestimate the actual occurrence of “TIA-like” ICH, since patients with minor, time-limited symptoms may not seek medical attention, may not be sent for immediate neuroimaging by healthcare providers, or may not even be imaged in the emergency department. A particularly vulnerable population might be patients with a history of multiple prior TIAs. These patients may not undergo repeated imaging and may already be treated with “definitive” antiplatelet therapy (such as a combination of aspirin and clopidrogrel).
Cerebral amyloid angiopathy (CAA) is associated with a “TIA-like” presentation, which is believed to result from micro-hemorrhages setting off a migraine-like cortical spreading depression. In this study, CAA was found minimally, but only 11 of these patients underwent MRI with gradient ECHO sequences. Most of the hemorrhages in this study, located in the basal ganglia and attributed to hypertension, were small and favorably located, causing neurological compromise that was fleeting and mild. In these hemorrhages, motor or sensory tracts may not be directly involved or may be “pushed aside” by a small amount of blood. Isolated seizures also may explain TIA-like symptoms in patients who are otherwise suffering from asymptomatic hemorrhages.
Similar to the ABCD2 score, ICH prognostication may be made using the “ICH score.” However, among the patients studied here, the ICH score would be nearly zero. Few would have met the criteria of age > 80 or ICH volume > 30, and none would have met criteria of Glasgow Coma Scale < 13, intraventricular extension, or infratentorial location. As the authors noted, while TIA might be a harbinger of severe stroke to follow, these patients uniformly had an excellent prognosis.