Detection of Right-to-Left Shunts may be Associated with Body Size

Relevance of small right-to-left shunt in contrast-enhanced transcranial Doppler in young and middle-aged patients with cryptogenic stroke: a report of two cases and literature review

AIM

The clinical relevance of small right-to-left shunt (RLS) in young patients with cryptogenic stroke is unknown. We aimed to analyze and understand the relationship between cryptogenic stroke and small RLS by studying specific cases.

MATERIALS AND METHODS

Clinical data from two cases of small RLS-related cryptogenic stroke in young patients were collected prospectively and analyzed. We followed up the patients for >1 year after discharge.

RESULTS

Case 1. A 50-year-old man was admitted for slurred speech and right hemiplegia and was diagnosed with acute cerebral infarction. Contrast-enhanced transcranial Doppler (c-TCD) and contrast-enhanced transthoracic echocardiography (c-TTE) revealed a microbubble and 20-30 microbubbles per section, respectively, in the resting state. Three months later, he was readmitted for stroke recurrence. Transesophageal echocardiography (TEE) confirmed a patent foramen ovale (PFO), and he underwent transcatheter closure of the PFO. Case 2. A 48-year-old man was admitted for right hemiplegia with slurred speech. Brain magnetic resonance imaging showed acute cerebral infarction. c-TCD and contrast-enhanced TEE (c-TEE) revealed <10 microbubbles and approximately 20 microbubbles per section, respectively. These findings suggested a PFO. Two months later, he was readmitted for stroke recurrence. He underwent transcatheter closure of the PFO. Follow-up of cases 1 and 2 at >1 and >1.5 years after discharge, respectively, showed no stroke recurrence.

CONCLUSION

We suspected that a small RLS may cause cryptogenic stroke. A small RLS in c-TCD in stroke patients may not be actually small, and c-TEE/c-TTE may be valuable in finding larger RLSs.

Multiple Infarcts Are Associated With Long-Term Stroke Recurrence and All-Cause Mortality in Cryptogenic Stroke Patients

Background and Purpose—

Brain infarct patterns that are observed via diffusion-weighted imaging are useful for classifying stroke subtypes. However, it is unclear whether infarct patterns can predict long-term outcomes in cryptogenic stroke patients. Herein, we investigated the association between acute brain infarct patterns and long-term stroke outcomes in cryptogenic stroke patients.

Methods—

Acute cryptogenic stroke patients were consecutively enrolled between April 2008 and March 2012. Diffusion-weighted imaging ischemic lesion patterns were classified as single lesions, scattered lesions in one vascular territory, or multiple lesions in multiple vascular territories. Survivors (at discharge) were followed up for 3 years after stroke onset.

Results—

A total of 272 cryptogenic stroke patients (132 women; aged 72±13 years) were enrolled. Among these patients, 169 (62.1%) had a single lesion, 38 (14.0%) had scattered lesions, and 65 (23.9%) had multiple lesions. Next, 261 patients (96.0%) were evaluated to assess right-to-left shunting, and 61 patients (23.4%) exhibited right-to-left shunting. On patient admission, right-to-left shunting and increased D-dimer levels were independently associated with multiple lesions but not single or scattered lesions. During the follow-up period (median, 1093 days), 30 patients (11.0%) developed recurrent stroke and 35 patients (12.9%) died. Multivariate Cox proportional hazard analyses showed that multiple infarcts were independently associated with recurrent stroke and all-cause mortality (hazard ratio, 3.79; 95% confidence interval, 2.24–6.37; P <0.001).

Conclusions—

Multiple brain infarcts on diffusion-weighted imaging were independently associated with long-term stroke outcomes in cryptogenic stroke patients.

Two different days of transcranial Doppler examinations should be performed for detection of right-to-left shunt in acute stroke patients

BACKGROUND

We investigated how many contrast-transcranial Doppler (c-TCD) examinations should be performed on different days in patients with acute stroke.

METHODS

Consecutive acute stroke patients within 24 hours of onset were enrolled. Presence of RLS was examined using c-TCD examinations on days 1, 7, and 14. Each c-TCD examination used one test without Valsalva maneuver (VM) and three tests with VM. Patients were diagnosed with RLS when TCD detected ≥1 microembolic signal on ≥1 c-TCD examination on any of the days 1, 7, or 14.

RESULTS

One hundred seventy patients (105 men [62%]; median age, 74 [IQR, 66-81] years) were enrolled. RLS was diagnosed in 45 patients (26%). RLS was identified on day 1 in 30 patients (18%), on day 7 in 28 patients (16%), and on day 14 in 23 patients (14%; P = .143). Detection rate of RLS by combining day 1 and 7 examinations was significantly higher than that of day 1 alone (25% vs. 18%, P < .001). However, the rate did not increase when results of day 14 were added (25% vs. 26%, P = .250).

CONCLUSIONS

c-TCD examinations should be performed on at least two different days to assess the prevalence of RLS.