Lateral Medullary Infarction With Atonic Bladder and Lateropulsion

Lateral medullary infarction (LMI), or Wallenberg syndrome, can develop various symptoms, but it is rare that ipsilateral axial lateropulsion (or body lateropulsion, BL) or atonic bladder (AB) are caused by LMI. This report describes a case of LMI with both BL and AB. A 77-year-old man, with a history of hypertension and diabetes, developed acute left BL and anuresis. A neurological exam showed right gaze nystagmus, slight dysarthria and dysphagia, right dysesthesia in the trunk, and ataxia in the left limbs and trunk. Horner's syndrome and paralysis were unremarkable. Brain magnetic resonance imaging revealed hyperintensity in the lateral medulla oblongata. Cystometry revealed AB, although the patient had the urge to urinate. Owing to acute therapy, although trunk ataxia was presented for several months, BL and anuresis were recovered on day 15 and day 35, respectively. Here, we describe the potential mechanisms of BL and AB caused by LMI.

[Bilateral vocal cord paralysis with acute airway obstruction and urgent tracheotomy in a patient with an acute vertebrobasilar stroke]

INTRODUCTION

Vertebrobasilar stroke can be a diagnostic challenge. Bilateral vocal cord paralysis is very rare as a manifestation of acute stroke, yet it is potentially life-threatening because of the possibility of acute airway obstruction. No cases of bilateral vocal cord paralysis have been reported as a presenting symptom of acute stroke of mixed central and peripheral neurological aetiology.

CASE REPORT

An 88-year-old woman with dysphonia resulting from paralysis of the right vocal cord following a thyroidectomy presented with sudden onset of vertigo, dysmetria and mild dysarthria (National Institutes of Health Stroke Scale: 2) associated with arterial hypertension. An urgent brain computed tomography (CT) scan evidenced distal occlusive thrombosis of the left vertebral artery without established ischaemia. Due to the improvement of symptoms achieved with control of her blood pressure, revascularisation therapy was not performed. Four hours later, the patient suddenly developed inspiratory stridor and severe respiratory failure due to bilateral vocal cord paralysis with complete airway obstruction. An urgent tracheotomy was performed, which resulted in an improvement in her breathing. A control brain CT scan performed at 24 hours showed established infarction in the left hemicerebellum and lateral medullary region, consistent with the territory of the left posterior inferior cerebellar artery.

CONCLUSION

Our case illustrates the possibility of the rare occurrence of acute bilateral vocal cord paralysis in the context of acute stroke in conjunction with chronic peripheral involvement of the recurrent laryngeal nerve. Although exceptional, it exemplifies the potential risk associated with vertebrobasilar strokes. A more aggressive reperfusion therapy may be appropriate in these cases, despite an initially mild deficit, because of the possibility of progression to life-threatening complications.

Pain Mimicking Trigeminal Neuralgia in Patients with Acute Ischemic Stroke of the Brainstem

BACKGROUND AND PURPOSE

Cases of pain mimicking trigeminal neuralgia (TN) induced by ischemic stroke in the brainstem have been sparsely reported. The study was to determine the characteristics of symptomatic TN in patients with acute ischemic stroke in the medulla oblongata and pons, and to determine the location of the ischemic lesion associated with the pain.

PATIENTS AND METHODS

A total of 6/21 (28.5%) patients with medullary ischemic stroke and 3/34 (8.8%) patients with pontine ischemic stroke who experienced pain mimicking TN between 1 week before and 2 weeks after the stroke onset were enrolled in the study. All patients accepted neuroimaging examinations to determine the location of the ischemic lesion and the etiology of ischemic stroke. The characteristics of pain were recorded and analyzed.

RESULTS

Ischemic lesions of patients who experienced pain mimicking TN were located in the lateral medulla oblongata (n=6), nerve root entry zoo (n=2), and areas involved with the spinal trigeminal tract (n=1) in the pons. Half of the instances of pain induced by medullary ischemic stroke occurred prior to the stroke onset. The branch of V1 was exclusively involved in patients with lateral medullary infarction and the branches of V2 and V3 were typically involved in patients with pontine infarction. The pain was relieved spontaneously (n=4, 44.4%) or was controlled with drugs for neuropathic pain treatment (n=5, 55.5%).

CONCLUSION

Half of the instances of pain induced by medullary ischemic stroke occurred prior to the stroke onset. Pain mimicking TN might be a premonitory symptom of the medullary ischemic stroke. Pain mimicking TN induced by brainstem infarction has a good prognosis.

Characteristics and Prognostic Factors of Swallowing Dysfunction in Patients with Lateral Medullary Infarction

OBJECTIVES

Lateral medullary infarction mainly impairs the pharyngeal phase of swallowing. We aimed to investigate the utility of the assessment tools of swallowing function in patients with lateral medullary infarction and to determine the factors that could predict the outcomes of swallowing function.

MATERIALS AND METHODS

15 patients with lateral medullary infarction who were admitted to Suiseikai Kajikawa Hospital between August 1, 2016, and March 31, 2020 (age 62.7 ± 14.8 years, 5 women) were enrolled in this prospective study. The diagnosis was made using brain magnetic resonance imaging. We analyzed the factors associated with severe swallowing dysfunction, which was defined as the necessity for tube feeding on the 90th day from admission, with multiple logistic regression analysis.

RESULTS

Multivariate analyses identified the repetitive saliva swallowing test, modified water swallowing test, and vertical spread of stroke lesions as independent significant factors affecting severe swallowing dysfunction (p = 0.002, 0.016, and 0.011, respectively). The sub-scores of the pharyngeal phase of the Mann Assessment of Swallowing Ability were also significantly associated with severe swallowing dysfunction (p < 0.001). However, tongue pressure, severe passage pattern abnormality on videofluoroscopic examination, and vertebral artery dissection were not significantly associated with swallowing dysfunction.

CONCLUSIONS

Since lateral medullary infarction presents with swallowing dysfunction mainly in the pharyngeal phase, tools that can be used to evaluate the pharyngeal phase of swallowing, such as repetitive saliva swallowing test and modified water swallowing test, are moreuseful than tongue pressure measurement.

DEFENSIVE Stroke Scale: Novel Diagnostic Tool for Predicting Posterior Circulation Infarction in the Emergency Department

BACKGROUND

Dizziness is the most common posterior circulation symptom; however, diagnosing a posterior circulation infarction is difficult due to a lack of typical symptoms. We aimed to investigate the frequency of misdiagnosis of a posterior circulation infarction in patients who presented with dizziness and to develop a new stroke scale that increased the diagnostic accuracy for stroke among these subjects.

METHODS

We retrospectively analyzed consecutive data from subjects hospitalized with ischemic stroke who presented with dizziness (the developmental phase). Based on these results, we created a novel stroke scale, which was used as a diagnostic procedure in the prospective validation phase. We compared the rate of misdiagnosis of ischemic stroke between phases.

RESULTS

During the development phase, 115 subjects were hospitalized for ischemic stroke accompanied by dizziness. Six ischemic stroke subjects were not properly diagnosed (6/115, 5.2%). We created the new DisEquilibrium, Floating sEnsation, Non-Specific dizziness, Imbalance, and VErtigo (DEFENSIVE) stroke scale to prevent underdiagnosis of a posterior circulation infarction. During the validation phase, 949 subjects with dizziness were examined with the DEFENSIVE stroke scale; among these subjects, 100 were hospitalized for ischemic stroke accompanied by dizziness. No subject with ischemic stroke was overlooked. The new DEFENSIVE stroke scale had a sensitivity of 100% and decreased the rate of improper diagnosis of stroke (5.2% versus 0%; P = .022).

CONCLUSIONS

Our new stroke recognition instrument for a posterior circulation infarction presenting with dizziness and related symptoms (the DEFENSIVE stroke scale) is easy to administer and has good diagnostic accuracy.

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.

A case of lateral medullary infarction with severe dysphagia and worsening of respiratory failure in the chronic phase of recovery

Patients with lateral medullary infarction (LMI) sometimes present with respiratory failure in the acute or subacute phase. We experienced a LMI patient with progression of respiratory failure that required bilevel positive airway pressure in the chronic phase. LMI patients must be carefully observed even in the chronic phase of recovery.

Three atypical manifestations of granulomatosis with polyangiitis: lateral medullary syndrome, anterior cheek mass and melting scleritis of eye

Granulomatosis with polyangiitis (GPA, formerly Wegener granulomatosis) is a vasculitis with various organ involvement. There have been a few cases of CNS stroke and rare cases of lateral medullary infarction (LMI) as a manifestation of GPA. Also there have been reports of sinuses, nose and laryngeal masses mistakenly referred as carcinomas and subsequently GPA was diagnosed in their pathological reports. Another severe fulminant manifestation can be necrotizing scleritis leading to perforation of sclera. Therefore, here we present some rare and fulminant manifestations of GPA in 3 separate cases for further emphasis of the unusual manifestations of GPA that should always be kept in mind.

Central Hypoventilation Syndrome Complicated with Lateral Medullary Infarction after Endovascular Treatment of the Vertebral Artery Dissecting Aneurysm: A Case Report

Lateral medullary infarction rarely leads to central hypoventilation syndrome (CHS). CHS is a life-threatening disorder characterized by hypoventilation during sleep. We report the first case of CHS as a complication of lateral medullary infarction after endovascular treatment. A 65-year-old man presented twice with severe headache. Computed tomography revealed subarachnoid hemorrhage and cerebral angiography showed a right vertebral dissecting aneurysm involving the posterior inferior cerebellar artery. After emergent endovascular patent artery occlusion, he developed Wallenberg syndrome and experienced apnea and a conscious disturbance episode due to CHS on postoperative days 6 and 16. Intensive respiratory care including intubation, tracheostomy, mechanical ventilation, and rehabilitation prevented subsequent recurrence of apnea and the CHS resolved completely. CHS after unilateral medullary infarction involving respiratory centers tends to occur in the acute and subacute phase and may be lethal without careful respiratory management.

Transient Vestibulopathy in Wallenberg's Syndrome: Pathologic Analysis

Objective

To report an unusual lateral medullary stroke (LMS) associated with transient unidirectional horizontal, nystagmus, and decreased horizontal vestibulo–ocular reflex (h-VOR) gain that mimicked a peripheral vestibulopathy. MRI suggested involvement of caudal medial vestibular nucleus (MVN); however, the rapid resolution of the nystagmus and improved h-VOR gain favored transient ischemia without infarction. Decreased h-VOR gain is expected with peripheral vestibular lesions within the labyrinth or superior vestibular nerve; less frequently lateral pontine strokes involving the vestibular root entry, the vestibular fascicle, or neurons within the MVN may be responsible. The h-VOR is typically normal in LMS.

Methods

Clinicopathologic examination of a 61-year-old man with an acute vestibular syndrome (AVS) and left LMS who died 3 weeks after the stroke. Postmortem brainstem analysis was performed.

Results

The stroke involved the lateral medulla and pontomedullary junction, near the MVN, sparing the cerebellum and pons. To explain transient vestibular findings there are two possible hypotheses; the first would be that the MVN survived the ischemic process and would be histologically intact, and the second that vestibular afferents in the horizontal semicircular canal were ischemic and recovered after the ischemic process. Neuropathological examination showed a left LMS whose extent matched that seen by imaging. Non-ocular motor signs correlated well with structures affected by the infarction. Neurons and glia within nearby MVN were spared, as predicted by the rapid normalization of the ocular motor signs. Although unlikely, the possibility of transient intralabyrinthine arteriolar ischemia cannot be excluded. Additionally, truncal lateropulsion was due to combined lateral vestibulospinal tract and lateral reticular nucleus infarction.

Conclusion

LMS may rarely be associated with an AVS that either represents or mimics a peripheral vestibulopathy. To our knowledge, this is the first neuropathologic examination of the brainstem of an LMS associated with transient vestibular findings occurring in the context of an anterior/posterior (AICA/PICA) cerebellar arterial variant stroke.

Dermatomal Sensory Manifestations in Opalski Syndrome

A 31-year-old Japanese woman presented with sudden-onset unstable gait followed by nuchal pain. A neurological examination revealed right-sided limb weakness and decreased pain and thermal sensation on the left side below the level of the L1 dermatome. A lower lateral medullary infarction with ipsilateral hemiplegia, known as Opalski syndrome, caused by spontaneous vertebral artery dissection was diagnosed by magnetic resonance imaging. The spinothalamic tract in the medulla oblongata has a topographic arrangement of sensory fibers, and the dermatomal sensory deficit in this case can be explained in relation to that. This is the first reported case of Opalski syndrome with dermatomal sensory manifestations. Opalski syndrome could be a differential diagnosis for dermatomal sensory manifestations.

[Giant partially thrombosed aneurysm of the vertebral artery: a case report and literature review]

INTRODUCTION

Giant partially thrombosed aneurysms of the vertebral artery are recalcitrant to treatment by microsurgical trapping and thrombectomy. Application of endovascular interventions is limited due to substantial brainstem compression and cranial nerve neuropathy. Combined endovascular exclusion and microsurgical excision provides an approach to treatment of these lesions.

CLINICAL CASE

A 48-year-old female patient presented with progressive complaints of ataxia, diplopia in left lateral gaze, and dysphagia. Imaging studies (CT, MRI, angiography) revealed a giant partially thrombosed aneurysm of the right vertebral artery and pronounced brainstem compression.

TREATMENT

The initial phase of treatment involved endovascular occlusion of the vertebral artery and aneurysm trapping that did not lead to changes in the postoperative patient's neurological status. MRI demonstrated complete aneurysm thrombosis and a weak TOF signal in the vertebral artery near the proximal aneurysm neck region. Because of persistent brainstem compression, the patient underwent right suboccipital craniectomy and hemilaminectomy of the CI arch for aneurysm excision one week after endovascular occlusion. After isolating the aneurysmal sac, the vertebral artery was transected, and two small branches extending from the aneurysm neck to the brainstem were also coagulated and transected, followed by aneurysm excision. Numerous vasa vasorum in the wall of the proximal vertebral artery and aneurysm neck were coagulated to stop bleeding. After surgery, the patient developed neurological symptoms (right leg ataxia and dysphagia worsening) due to lateral medullary infarction (confirmed by MRI) that presumably resulted from coagulation of two small perforating branches coming from the aneurysm neck to the brainstem. Recovery of the patient's neurological functions was observed during conservative treatment. The patient was discharged with mild right leg ataxia and preoperative left-sided abducens paresis.

CONCLUSION

Medulla oblongata compression associated with a giant thrombosed aneurysm of the vertebral artery can be eliminated by endovascular trapping followed by surgical excision of the aneurysm. Preserving the vasa vasorum feeding the brainstem is crucial for prevention of ischemic complications.

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

BACKGROUND AND PURPOSE

The functional recovery after the lateral medullary infarction (LMI) is usually good. Little is known about the prognostic factors associated with poor outcome following acute LMI. The aim of this study was to identify the factors associated with poor long-term outcome after acute LMI, based on experiences at a single center over 11 years.

METHODS

A consecutive series of 157 patients with acute LMI who were admitted within 7 days after symptom onset was evaluated retrospectively. Clinical symptoms were assessed within 1 day after admission, and outcomes were evaluated over a 1-year period after the initial event. The lesions were classified into three vertical types (rostral, middle, and caudal), and the patients were divided into two groups according to the outcome at 1 year: favorable [modified Rankin Scale (mRS) score ≤1] and unfavorable (mRS score ≥2).

RESULTS

Of the 157 patients, 93 (59.2%) had a favorable outcome. Older age, hypertension, dysphagia, requirement for intensive care, and pneumonia were significantly more prevalent in the unfavorable outcome group. The frequencies of intensive care (13%) and mortality (16.7%) were significantly higher in the rostral lesion (p=0.002 and p=0.002). Conditional logistic regression analysis revealed that older age and initial dysphagia were independently related to an unfavorable outcome at 1 year [odds ratio (OR)=1.04, 95% confidence interval (95% CI)=1.001-1.087, p=0.049; OR=2.46, 95% CI=1.04-5.84, p=0.041].

CONCLUSIONS

These results suggest that older age and initial dysphagia in the acute phase are independent risk factors for poor long-term prognosis after acute LMI.

A dilated surface appearance on basiparallel anatomic scanning-magnetic resonance imaging is a useful tool for the diagnosis of spontaneous vertebral artery dissection in lateral medullary infarction

Spontaneous dissection of the vertebral artery (VA) is a major vascular lesion causing lateral medullary infarction (LMI). A dilated surface appearance of the VA is a feature of VA dissection and can be observed on basiparallel anatomic scanning (BPAS)-magnetic resonance imaging (MRI). The aim of this study was to validate BPAS-MRI in the diagnosis of VA dissection in patients with LMI. The subjects of the present study were 41 consecutive patients with LMI within 7 days of onset. The diagnosis of VA dissection was made with the clinical criteria-based diagnosis. Percent (%) dilatation of the VA on BPAS-MRI was calculated by comparing the maximum surface diameter of the intracranial VA to the diameter of the distal normal surface of the VA. Fourteen patients (34%) were diagnosed with VA dissection. The optimal cutoff % dilatation of the VA for dissection was more than 169%. The sensitivity and specificity of % dilatation of VA more than 169% and aneurysmal dilatation, stenosis, or occlusion on magnetic resonance angiography (MRA) for VA dissection were 92.9% and 81.5%, respectively. BPAS-MRI combined with time-of-flight-MRA is a useful tool for the diagnosis of VA dissection in patients with acute LMI.

Ipsilateral sensorimotor deficits in lateral medullary infarction: a case report

The patient, a 32-year-old man, presented with sudden onset of occipital headache, vertigo, dysarthria, gait ataxia, right Horner syndrome, numbness of the right hand, and mild right hemiparesis. On magnetic resonance imaging, an acute small infarction was located on the right side of the caudal medulla extending dorsomedially. Magnetic resonance angiography showed severe right vertebral artery stenosis. Lateral medullary infarction associated with ipsilateral sensorimotor deficits in the limb is very rare, and the lesion probably involved the ipsilateral dorsal column or decussating lemniscal fibers and corticospinal fibers caudal to the pyramidal decussation or compression of the decussation.

Dermatomal sensory manifestations in lateral medullary infarction

A 61-year-old man who experienced a sudden onset of unstable gait followed by nuchal pain was admitted to our department. The neurologic examination revealed right-sided limb ataxia, right partial ptosis, and decreased sensation to 50% of the normal side to pinprick and temperature stimuli on the left side below the level of the T-6 dermatome. A lateral medullary infarction caused by spontaneous vertebral artery dissection was diagnosed by magnetic resonance imaging and computed tomography angiography. In conclusion, lateral medullary infarction is an important entity to consider in the differential diagnosis of dermatomal sensory manifestations.

Dysphagia caused by a lateral medullary infarction syndrome (Wallenberg's syndrome)

A 68-year-old man was referred to our hospital for a dysphagia evolving for 10 days. Clinical examination had found neurological signs as contralateral Horner's syndrome, ipsilateral palatal paresis, gait ataxia and hoarseness. Video-fluoroscopy showed a lack of passage of contrast medium to the distal esophagus. Esogastroduodenoscopy was normal. The cranial MRI had shown an acute ischemic stroke in the left lateral medullar region and the diagnosis of Wallenberg syndrome (WS) was established. WS remains an unknown cause of dysphagia in the clinical practice of the gastroenterologist.

Impaired sacculocollic reflex in lateral medullary infarction

OBJECTIVE

The aim of this study was to determine saccular dysfunction by measuring cervical vestibular-evoked myogenic potentials (cVEMP) and to correlate abnormality of cVEMP with results of other vestibular function tests in lateral medullary infarction (LMI).

METHODS

We recorded cVEMP in 21 patients with LMI documented on MRI. cVEMP was induced by a short tone burst and was recorded in contracting sternocleidomastoid muscle while patients turned their heads forcefully to the contralateral side against resistance. Patients also underwent video-oculographic recording of spontaneous, gaze-evoked and head shaking nystagmus (HSN), evaluation of ocular tilt reaction (OTR), measurement of the subjective visual vertical (SVV) tilt, bithermal caloric tests, and audiometry.

RESULTS

Nine patients (43%) showed abnormal cVEMP, unilateral in seven and bilateral in two. The cVEMP abnormalities included decreased p13-n23 amplitude in four, delayed p13/n23 responses in five, and both decreased and delayed responses in two. The abnormal cVEMP was ipsilesional in five, contralesional in two, and bilateral in two. The prevalence of OTR/SVV tilt, spontaneous nystagmus, and HSN did not differ between the patients with normal and abnormal cVEMP.

CONCLUSION

cVEMP was abnormal in approximately half of the patients with LMI. The abnormal cVEMP indicates damage to the descending sacculocollic reflex pathway or disruption of commissural modulation between the vestibular nuclei.