Dysphagia May Be an Independent Marker of Poor Outcome in Acute Lateral Medullary Infarction

Clinical and Radiological Characteristics Associated with Respiratory Failure in Unilateral Lateral Medullary Infarction

BACKGROUND

The prognosis for unilateral lateral medullary infarction (ULMI) is generally good but may be aggravated by respiratory failure with fatal outcome. Respiratory failure has been reported in patients with severe bulbar dysfunction and large rostral medullary lesions, but its associated factors have not been systematically studied. We aimed to assess clinical and radiological characteristics associated with respiratory failure in patients with pure acute ULMI.

MATERIALS AND METHODS

Seventy-one patients (median age 55 years, 59 males) with MRI-confirmed acute pure ULMI were studied retrospectively. Clinical characteristics were assessed and bulbar symptoms were scored using a scale developed for this study. MRI lesions were classified into 4 groups based on their vertical extent (localized/extensive) and the involvement of the open and/or closed medulla. Clinical characteristics, bulbar scores and MRI lesion characteristics were compared between patients with and without respiratory failure.

RESULTS

Respiratory failure occurred in 8(11%) patients. All patients with respiratory failure were male (p = 0.336), had extensive lesions involving the open medulla (p = 0.061), progression of bulbar symptoms (p=0.002) and aspiration pneumonia (p < 0.001). Peak bulbar score (OR, 7.9 [95% CI, 2.3-160.0]; p < 0.001) and older age (OR, 1.2 [95%CI, 1.0-1.6]; p=0.006) were independently associated with respiratory failure.

CONCLUSIONS

Extensive damage involving the open/rostral medulla, clinically presenting with severe bulbar dysfunction, in conjunction with factors such as aspiration pneumonia and older age appears to be crucial for the development of respiratory failure in pure ULMI. Further prospective studies are needed to identify other potential risk factors, pathophysiology, and effective preventive measures for respiratory failure in these patients.

Risk Factors for Long-Term Death After Medullary Infarction: A Multicenter Follow-Up Study

Background and Purpose: We investigated the risk factors for death in patients with medullary infarction (MI) during a long-term follow-up.

Methods: We retrospectively examined 179 consecutive patients (130 men and 49 women) who had clinical and MRI findings consistent with MI between February 2012 and January 2017 at three university hospitals. Long-term outcomes were assessed by telephonic interview. The clinical and radiological features and risk factors for poor outcomes (modified Rankin scale score ≥ 3, all-cause death) were analyzed.

Results: Mean age of patients was 58.3 ± 12.8 years (range, 25–87); mean follow-up period after stroke onset was 42.7 ± 13.2 months (range, 24–78). Basilar artery (BA) stenosis >50% was more closely related to medial medullary infarction (MMI) than other types. There was greater frequency of ipsilateral vertebral artery hypoplasia (VAH) or V4AH and V4 occlusion in lateral MI than in other types. On rostro-caudal classification, middle (M)+dorsal (D) was most frequent, followed by the ventral (V)+M+D types. 21.2% patients showed poor long-term prognosis. Age ≥ 65 years, recurrent stroke, dysphagia, >50% BA stenosis, and ventral MI were risk factors for poor long-term prognosis. All-cause mortality rate was 10.6%; age ≥ 65 years, recurrent stroke, and dysphagia were risk factors for death in the long-term. Ventral MI and MMI+cerebellar infarction, as well as stroke mechanism of artery-to-artery embolism, were potential risk factors for death in the long-term. Pneumonia and recurrent stroke were major causes of death.

Conclusions: Long-term poor outcomes of MI and all-cause mortality were not infrequent. Older age, recurrent stroke, and dysphagia were common risk factors for poor prognosis and death.

Efficacy of Early Endoscopic Intervention for Restoring Normal Swallowing Function in Patients with Lateral Medullary Infarction

Dysphagia is considered to be a significant barrier for recovery after lateral medullary infarction (LMI). However, there is still no gold standard treatment for dysphagia. The aim of this study was to explore an effect of an early treatment options for swallowing dysfunction after acute LMI. Medical records of acute LMI patients who had been admitted to the department of rehabilitation medicine from January 2014 to December 2017 were reviewed retrospectively. We compared the clinical efficacy of conventional dysphagia rehabilitation to early endoscopic intervention using either botulinum toxin injection into cricopharyngeal muscle or endoscopic balloon dilatation of the muscle. Outcomes, such as duration of parental feeding, albumin level at diet transition to enteral feeding, and complications, were analyzed. A total of 18 patients with LMI were included. While eight patients (8/9, 88.89%) in the endoscopic group were capable of orally ingesting their diet after intervention, the conversion from tube feeding to an oral diet was possible in only five patients (5/9, 55.56%) of the conventional group during hospitalization. However, the difference between the two groups was not significant (p-value ≤ 0.147, chi-square test). Only the final dietary level at the time of discharge was higher level in endoscopic group. The conversion interval from tube feeding to oral diet was also comparable between groups. There was no re-conversion from the oral diet to tube feeding in patients of either group during the median follow-up period of 20 months. Early endoscopic intervention may be a better option for dysphagia with LMI, compared to conventional dysphagia rehabilitation. However, a larger and prospective trial may be needed to confirm our observations.

Stroke mechanisms and their correlation with functional outcome in medullary infarction

PURPOSE

To study the stroke mechanism of medullary infarction (MI) and their correlation with prognosis.

METHODS

We collected 81 consecutive patients with acute isolated MI including 50 patients with lateral MI (LMI), 30 with medial MI (MMI) and one with combined MI. The stroke mechanisms were defined as follows: 1. Large artery atherosclerotic occlusive disease (LAOD): with severe stenosis (>50%) or occlusion on the relevant arteries. 2. Penetrating artery disease (PAD): occlusion of penetrating arteries that arise from vertebral artery or basilar artery with no significant stenosis of the vertebro-basilar artery. 3. Dissection: angiographic findings met the criteria. 4. Cardiogenic embolism: abrupt onset with atrial fibrillation. The poor outcome was defined as a condition that includes the mRS ≥2 and/or dysphagia at one year after onset.

RESULTS

There were 20 patients with PAD (40%), 18 with dissection (36.0%) and 11 with LAOD (22.0%) in LMI and 17 with PAD (56.6%), 10 with LAOD (33.3%) in MMI. LAOD and dissection compared with PAD were independently correlated with poor outcome in LMI (OR: 12.8, p = 0.029 and OR: 14.9, p = 0.035). LAOD was significantly correlated with poor outcome in MMI (OR: 13.4, p = 0.014).

CONCLUSIONS

PAD was the most predominant stroke mechanism in MI and generally showed favorable outcome. Patients with LAOD and dissection showed worse outcome than those with PAD.

Lateral Medullary Infarction with or without Extra-Lateral Medullary Lesions: What Is the Difference?

BACKGROUND

Lateral medullary infarction (LMI) is not an uncommon disease. Although lesions are usually restricted to the lateral medullary area, some patients have additional infarcts in other parts of the brain. The clinical features and prognosis of isolated LMI (pure LMI, LMIpr) have been investigated. However, it remains unclear whether clinical characteristics, prognosis and factors associated with prognosis differ between patients with LMIpr and those with additional lesions (LMI plus, LMIpl).

METHODS

Patients with LMI identified by MRI were enrolled. The demographic and clinical characteristics, in-hospital outcome (intensive care unit [ICU] admission, pneumonia and modified Rankin scale [mRS] at discharge), and long-term residual symptoms (vertigo/dizziness, sensory disturbances, dysphagia) and outcomes (occurrence of stroke, acute coronary syndrome [ACS], death, and mRS at follow-up) were compared between LMIpr and LMIpl patients. Factors associated with poor functional outcome (mRS 2-6) at the follow-up were analyzed.

RESULTS

Among 248 LMI patients, 161 (64.9%) had LMIpr and 87 (35.1%) had LMIpl. During admission, patients with LMIpl more frequently experienced ICU care, pneumonia and had a higher discharge mRS (3 vs. 2; p < 0.001) than LMIpr patients. The occurrence of stroke, ACS, frequency of death and functional outcome was not different during follow-up. However, residual neurologic symptoms such as dizziness (p = 0.002), dysphagia (p = 0.04) and sensory symptoms (p < 0.001) were more frequent in LMIpr than in LMIpl patients. In LMIpr patients, the rostral location of LMI was associated with poor functional outcome (p = 0.041), whereas in LMIpl patients, the presence of medial posterior-inferior cerebellar artery lesion was associated with good functional outcome (p = 0.030).

CONCLUSION

Although the short-term outcome is poorer in LMIpl than LMIpr patients, long-term residual symptoms are more common in LMIpr patients. The location of the LMI and extra-medullary lesion affects the long-term functional outcome of LMIpr and LMIpl patients respectively.