Usefulness of thermography for differentiating Wallenberg's syndrome from noncentral vertigo in the acute phase.

OBJECTIVES: Wallenberg's syndrome (WS) is caused by a stroke in the lateral medulla and can present with various symptoms. One of the main symptoms is vertigo, which can be misdiagnosed as noncentral vertigo (NCV). Approximately 90% of the patients with acute WS have a lateral difference in body surface temperature (BST) due to autonomic pathway disturbances from infarction. Additionally, thermography can aid in WS diagnosis; however, whether BST differences occur in patients with acute NCV is unclear. METHODS: This study used thermography to measure the BST of patients with NCV and acute WS to determine the effectiveness of BST to differentiate between the conditions. Forty-eight consecutive patients diagnosed with NCV whose BST was measured using thermography during a hospital visit or admission were enrolled. The left and right BST of four sites (face, trunk, and upper and lower limbs) were measured and compared with obtained BST of nine patients with WS. RESULTS: Twenty-two patients had lateral differences in BST ≥ 0.5°C, three with ≥1.5°C, and none with ≥2.5°C. Only one patient with NCV had lateral differences in BST at two or more ipsilateral sites. When WS differentiated from NCV, a left-right difference ≥0.5°C in two or more ipsilateral sites had a sensitivity of 89% and specificity of 98%, and ≥1.0°C had a sensitivity of 78% and specificity of 98%. DISCUSSION: Acute WS can be differentiated from NCV through BST and the number of sites with lateral differences via thermography, even in rooms where conditions are unregulated.

Severe Unilateral Proprioceptive Loss in Medullary- Rostral Spinal Cord Infarction. A Posterior Spinal Artery Syndrome.

We draw attention to a unique presentation, severe unilateral loss of limb proprioception, in patients with medullary and rostral spinal cord infarction. Two patients developed acute severe proprioceptive loss in the limbs ipsilateral to infarcts that involved the caudal medulla and rostral spinal cord. They also had symptoms and signs often found in lateral medullary infarction. The proprioceptive loss is attributable to injury to the gracile and cuneate nuclei and/or their projections to the medial lemniscus. The infarct territory is supplied by the posterior spinal branches of the vertebral artery near its penetration into the posterior fossa. The presence of severe ipsilateral proprioceptive loss in a patient with features of lateral medullary infarction indicates involvement of the rostral spinal cord.

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.

Posterior circulation stroke presenting as a new continuous cough: not always COVID-19.

A 19-year-old man was admitted with a 2-week history of continuous cough along with a day history of acute onset unsteadiness and hiccups. Given the current pandemic, he was initially suspected to have COVID-19, however he tested negative on two occasions. Subsequent brain magnetic resonance imaging (MRI)confirmed a small left acute and subacute lateral medullary infarction with chest X-ray suggesting aspiration pneumonia with right lower lobe collapse. This is a distinctive case of posterior circulation stroke presenting with a new continuous cough in this era of COVID-19 pandemic. We anticipate based on MRI findings that his persistent cough was likely due to silent aspiration from dysphagia because of the subacute medullary infarction. It is therefore imperative that healthcare workers evaluate people who present with new continuous cough thoroughly to exclude any other sinister pathology. We should also be familiar with the possible presentations of posterior circulation stroke in this pandemic era.

Breathing patterns in relation to sleep stages in acute unilateral lateral medullary infarction: An exploratory study.

Our aim was to perform an exploratory study of various irregular breathing patterns (IBPs) across different sleep stages in patients with acute unilateral lateral medullary infarction (ULMI) and compare them to apparently healthy individuals. Polysomnography (PSG) was analyzed for IBPs, such as periodic breathing, ataxic breathing and tachypnea. IBPs were found in 52 % of healthy and 90 % of ULMI subjects (p = 0.001) and occurred in long (≥ 10 min) episodes in 8% of healthy and 68 % of ULMI (p < 0.001). In healthy subjects, short (< 10 min) episodes of mild to moderate ataxic breathing were observed in wakefulness and light sleep and short episodes of periodic breathing upon sleep onset. In ULMI, the most common IBPs were ataxic and periodic breathing (80 % of patients), followed by shallow tachypnea (28 %). Ataxic breathing predominated in wakefulness, ataxic or periodic breathing in light sleep, while breathing tended to normalize in deep and REM sleep. Considering the IBPs occurring in the healthy group as physiological, probably pathological breathing patterns (tachypnea, long episodes of moderate/severe ataxic or long episodes of periodic breathing) occurred in 67 % of ULMI patients. Our findings suggest that ULMI might exacerbate physiological sleep-stage-dependent breathing pattern irregularities, such as ataxic and periodic breathing, in terms of intensity and duration or might even induce non-physiological IBP, such as shallow tachypnea with sustained hypoxia.

Lateral Medullary Syndrome Following Injury of Lateral Vestibulospinal Tract: Diffusion Tensor Imaging Study.

BACKGROUND: Unilateral lesions of vestibular nucleus can cause lateral medullary syndrome. Little is known about injury of medial and lateral vestibulospinal tract (VST) after dorsolateral medullary infarct. We investigated injury of the lateral VST in patients with typical central vestibular disorder using diffusion tensor tractography (DTT). METHODS: Seven patients with lateral medullary syndrome and ten control subjects were recruited. For the medial VST, we determined seed region of interest (ROI) as medial vestibular nuclei of pons and target ROI on posteromedial medulla. For the lateral VST, the seed ROI was placed on lateral vestibular nuclei of pons, and the target ROI on posterolateral medulla. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured. RESULT: Reconstructed lateral VST on both sides had significantly lower FA values in patients than controls (p<0.05). Tract volume of lateral VST in affected side was significantly lower than unaffected side and control group (p<0.05). However, no DTI parameters of the medial VST differed between patients and controls (p>0.05). CONCLUSION: Injury of the lateral VST was demonstrated in patients with lateral vestibular syndrome following dorsolateral medullary infarct. Analysis of the lateral VST using DTT would be helpful in evaluation of patients with lateral medullary syndrome.

Neuroanatomical basis of Wallenberg syndrome.

Wallenberg syndrome, or lateral medullar syndrome, is the clinical presentation of the infarct in the territory of posterior inferior cerebellar artery. Its signs and symptoms include vertigo, nystagmus, diplopia, ipsilateral Horner syndrome, facial ruddiness and dry skin, dysphonia, dysphagia, dysarthria, ipsilateral loss of gag reflex, ipsilateral ataxia, ipsilateral impaired taste, ipsilateral facial pain and paresthesia, decreased ipsilateral blink reflex, contralateral hypoalgesia and thermoanaesthesia in the trunk and limbs; and ipsilateral facial hypoalgesia and thermoanaesthesia. Neuroanatomical knowledge is essential to its comprehension, study and diagnosis, because the classic neurological manifestations are easy to explain and understand if function and localization of affected anatomical structures are known as if the posterior cerebral circulation is.

El síndrome de Wallenberg, o síndrome bulbar lateral, es la manifestación clínica del infarto en el territorio de irrigación de la arteria cerebelosa posteroinferior. Su presentación incluye vértigo, nistagmo, diplopía, síndrome de Horner, rubicundez y anhidrosis facial homolateral, disfonía, disfagia, disartria, pérdida homolateral del reflejo nauseoso, ataxia homolateral, disgeusia homolateral, dolor y parestesia faciales homolaterales, pérdida o disminución homolateral del reflejo corneal, hipoalgesia y termoanestesia de tronco y extremidades contralaterales, hipoalgesia y termoanestesia facial homolateral. El conocimiento neuroanatómico es imprescindible para su comprensión, estudio y diagnóstico, ya que sus manifestaciones neurológicas clásicas son fácilmente explicables y entendibles si se conocen la función y la localización de las estructuras anatómicas afectadas, así como la irrigación cerebral posterior.

Opalski Syndrome Treated with Intravenous Recombinant Tissue Type Plasminogen Activator-Case Report and Review of Literature.

A 65-year-old man with a history of Wallenberg syndrome caused by vertebral artery dissection at 62 years old was admitted to our hospital with nausea, vertigo, right facial dysesthesia, right hemiplegia, crossed sensory disturbance (sensory loss and numbness in the right face and left body below the neck), and right limb ataxia. Magnetic resonance imaging (MRI) performed 80 minutes after onset revealed no acute ischemic stroke lesions, but magnetic resonance angiography (MRA) demonstrated complete occlusion of the right vertebral artery. Based on these neurological and MRA findings, atypical lateral medullary infarction was suggested, and intravenous tissue plasminogen activator (IV-tPA) was started 178 minutes after onset. Right hemiplegia improved immediately after IV-tPA administration. MRI performed on hospital day 2 showed an acute ischemic lesion on the right side of the medulla oblongata, resulting in a diagnosis of Opalski syndrome. Opalski syndrome is a rare subtype of Wallenberg syndrome accompanied by hemiplegia of the side ipsilateral to the lesion, and expansion of the stroke lesion to the corticospinal tract below the pyramidal decussation is considered to cause ipsilateral hemiplegia. Based on this case and previous reports, Opalski syndrome should be considered when limb ataxia and crossed sensory deficit are observed among patients with hyperacute-onset hemiplegia, and IV t-PA therapy should be considered even in the absence of neurological findings such as dysphagia, dysarthria, and Horner's signs and radiological evidence of acute ischemic stroke.

Portable Thermographic Screening for Detection of Acute Wallenberg's Syndrome.

Wallenberg's syndrome (WS) is a type of brainstem infarction. WS patients often show Horner's syndrome, dissociated sensory disturbance, truncal ataxia, and hoarseness. However, they rarely show tactile sensory disturbance and paralysis of the extremities. Additionally, acute brainstem infarction is often not apparent in magnetic resonance images. These symptomatic and imaging characteristics sometimes lead to misdiagnosis of WS as a non-stroke disease, including auditory vertigo. Although careful neurological examination is necessary to prevent misdiagnosis of WS, this type of examination may be difficult for non-neurologists to whom affected patients initially present. Lateral differences in body surface temperature (BST) constitute a recognized and widespread symptom of WS. We previously reported that most acute WS patients exhibit lateral differences in BST at multiple locations and that these lateral differences in BST could easily be detected by thermographic measurement. Here, we present the method for use of portable thermography to detect acute WS, using a simple, rapid, noninvasive, and cost-effective approach. To assess lateral differences in BST among patients with suspected WS, BST was measured as soon as possible in the examination room or in the patient's bedroom. Measurements were performed bilaterally at four locations where images could easily be acquired (face, palm of the hand, abdomen, and dorsum of the foot) using a portable thermal camera. When lateral differences in BST are observed macroscopically, especially in multiple locations on the same side, a diagnosis of WS should be suspected. Macroscopic assessment of BST laterality can be made within 2 min of the acquisition of thermographic images. This method may be useful in preventing misdiagnosis of acute WS as a non-stroke disease, especially when such patients initially present to non-neurologists.

Disruption of the Obligatory Swallowing Sequence in Patients with Wallenberg Syndrome.

Although the sequence of events involved in swallowing varies among healthy adults, healthy adults demonstrate some consistent patterns, including opening of the upper esophageal sphincter (UES) prior to maximum laryngeal elevation (LE). Previous animal studies suggested that swallowing is regulated by a neuronal network in the medulla, and lateral medullary infarction, or Wallenberg syndrome, frequently causes dysphagia. This retrospective, observational, multicenter study aimed to determine if the sequence of swallowing events was disturbed in patients with Wallenberg syndrome compared with previously published reference data for healthy adults. The study subjects included 35 patients with Wallenberg syndrome admitted to three hospitals in Japan from 1/4/2009 to 31/3/2017. Sixteen timing events, including maximum LE and UES opening, and the intervals between events were measured. If the sequence of events was the same as in healthy adults, the interval value was positive, and if the sequence of events was opposite to that in healthy adults, the value was negative. The median interval from UES opening to maximum LE was - 0.02 s (range - 0.80 to 0.89, 95% CI - 0.14 to 0.10). About half of the Wallenberg cases showed negative values indicating that the sequence was reversed. These results suggest that lateral medullary infarction impairs the sequence of swallowing events.

Utility of thermographic measurements of laterality of body surface temperature to prevent misdiagnosis of acute Wallenberg's syndrome.

INTRODUCTION: Acute Wallenberg's syndrome (WS) is sometimes misdiagnosed as a nonstroke disease including auditory vertigo, and careful neurological examination is required for a precise diagnosis. Lateral difference of body surface temperature (BST) had been reported as a symptom of WS, although further details of this symptom are currently lacking. Our aim was to investigate the laterality of BST of patients with acute WS using thermography and the usefulness of thermography to detect acute WS. METHODS: Nine consecutive patients with new-onset acute WS and nine patients with acute pontine infarction, intended for a comparison, were enrolled. Using thermography, the BST of patients was measured and initially evaluated visually. Detailed BSTs were measured using dedicated software. We examined the relationship between BST and other clinical factors, including first diagnosis, clinical symptoms, and MRI findings. RESULTS: Four patients with WS (44.44%) were misdiagnosed with nonstroke disease and did not receive a thermography assessment at their first visit; in contrast, all acute pontine infarction patients were diagnosed with brain infarction. Eight patients with WS (89%) showed a laterality of BST at multiple sites, and three of eight patients showed a whole-body laterality of BST; in contrast, only two pontine infarction patients showed laterality of BST at one or two sites. These lateral BST differences were easily observed visually using thermography within two minutes. The BST laterality gradually decreased over time in almost all patients with WS. The infarction size in the WS patients with whole-body laterality of BST was craniocaudally larger than in the other patients, and the size was smallest in the patient showing no BST laterality. CONCLUSIONS: In contrast to acute pontine infarction patients, almost all patients with acute WS showed lateral BST differences, which was easily detected with thermography. Thermography may thus be a useful tool to prevent misdiagnosis of acute WS.

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.

Cervico-shoulder dystonia following lateral medullary infarction: a case report and review of the literature.

BACKGROUND: Secondary cervical dystonia is induced by organic brain lesions involving the basal ganglia, thalamus, cerebellum, and brain stem. It is extremely rare to see cervical dystonia induced by a medullary lesion. CASE PRESENTATION: We report a case of an 86-year-old Japanese woman who developed cervical dystonia following lateral medullary infarction. She developed sudden-onset left upper and lower extremity weakness, right-side numbness, and dysarthria. Brain magnetic resonance imaging revealed an acute ischemic lesion involving the left lateral and dorsal medullae. A few days after her stroke, she complained of a taut sensation in her left neck and body, and cervico-shoulder dystonia toward the contralateral side subsequently appeared. Within a few weeks, it disappeared spontaneously, but her hemiplegia remained residual. CONCLUSIONS: To date, to the best of our knowledge, there has been only one reported case of cervical dystonia associated with a single medullary lesion. It is interesting to note the similarities in the clinical characteristics of the previously reported case and our patient: the involvement of the dorsal and caudal parts of the medullary and associated ipsilateral hemiplegia. The present case may support the speculation that the lateral and caudal regions of the medulla may be the anatomical sites responsible for inducing cervical dystonia.

New Swallowing Method to Improve Pharyngeal Passage of a Bolus by Creating Negative Pressure in the Esophagus-Vacuum Swallowing.

Herein, we present a case of a patient with Wallenberg syndrome with severe bulbar dysphagia who discovered a unique swallowing method: creating strong negative pressure in the esophagus to improve pharyngeal passage of a bolus. A 47-yr-old man presented with a subarachnoid hemorrhage secondary to a ruptured aneurysm in the right vertebral artery. After coil embolization, he experienced severe dysphagia due to Wallenberg syndrome and required tube feeding. Eighty-one days after the onset of the stroke, a videofluoroscopic swallowing evaluation revealed that the bolus was rapidly sucked into the esophagus. High-resolution manometry showed weak constriction of the pharynx simultaneous with forced, voluntary constriction of the diaphragm before swallowing; this created negative pressure in the esophagus. The authors named this unique swallowing method "vacuum swallowing." Ultimately, the patient was able to eat an ordinary diet via the use of this technique. Vacuum swallowing is a unique method of improving pharyngeal passage of a bolus by creating strong negative pressure in the esophagus. Additional studies are necessary to determine whether vacuum swallowing can be successfully used for other forms of dysphagia.

Crossed cheiro-oral syndrome: A warning sign for medullary involvement and neurological deterioration.

Crossed cheiro-oral syndrome (CCOS) is characterized by crossed sensory disturbance confined to the unilateral perioral area and contralateral hand/finger(s). Although a few classical crossed sensory syndromes accurately predict brainstem or spinal involvement, the clinical significance of CCOS remains unclear. In this study, we analyzed the etiology, localization and outcome of CCOS patients. The results showed that ischemic stroke is the exclusive cause of CCOS. The location of responsible stroke is pertinent to the middle or upper level of the lateral medulla oblongata medial to the lateral sulcus. The vascular supply is from the vertebral artery or the posterior inferior cerebellar artery. Half of the CCOS patients progressed to Wallenberg's syndrome and complicated with disabled daily living. However, no patient died during the follow-up period. A larger size and dorsal extension of the infarction correlated with neurological deterioration. Therefore, CCOS is an independent clinical sign of medullary involvement. It strongly predicts involvement at the lateral medulla oblongata, especially the ischemic stroke, and neurological deterioration. A rapid evaluation of the infarction location and vascular status is suggested in cases of CCOS.

Perfusion weighted imaging in the assessment of the pathology and outcomes of lateral medullary infarction.

This series case report aimed to elucidate the underlying pathology and outcomes of lateral medullary infarction (LMI) using perfusion weighted imaging (PWI). Four patients were diagnosed with LMI based on high-field diffusion-weighted magnetic resonance imaging (MRI-DWI) and PWI. The national institutes of health stroke scale (NIHSS) scores were recorded on days 1, 7, and 30, and the Barthel index was assessed on days 7 and 30. Three patients exhibited relative regional hypoperfusion of medullary lesion in the perfusion maps. Two cases exhibited ipsilateral hypoperfusion in the inferior cerebellum, whereas one patient exhibited a relatively regional hyperperfusion in the medulla oblongata. The LMI patients with a high NIHSS score and low Barthel index on days 7 and 30 exhibited regional hypoperfusion. This report of 4 LMI cases provides preliminary evidence that regional hypoperfusion may contribute to worse outcomes in LMI.

Altered processing of otolithic information in isolated lateral medullary infarction.

Ocular and cervical vestibular-evoked myogenic potentials (VEMPs) evaluate the function of otolithic pathways in central as well as peripheral vestibular disorders. This study aimed to determine the associations and dissociations of otolithic dysfunction in lateral medullary infarction (LMI), the most well-known disorder of central vestibulopathy. At the Dizziness Clinic of a referral-based University Hospital, 45 patients with isolated LMI (28 men, mean age = 55.6 ± 12.5) had evaluation of the ocular tilt reaction (OTR), tilt of the subjective visual vertical (SVV), and ocular and cervical VEMPs from Janurary 2011 to August 2015 during the acute phase, 1-11 days from the symptom onset (median = 2 days). Almost all (42/45, 93 %) patients showed at least one component of the OTR or SVV tilt that was invariably ipsiversive. In contrast, oVEMPs were abnormal only in 12 (27 %) and cVEMPs in 13 (29 %) patients. Only three patients showed abnormal results in all the tests of the OTR, SVV tilt, and ocular and cervical VEMPs. Abnormal oVEMPs were more common in patients with the OTR than those without (38 vs 6 %, Pearson X 2 test, p = 0.021). In contrast, abnormality of cVEMPs showed no correlation with the presence of OTR (28 vs 31 %, Pearson X 2 test, p = 0.795). In patients with LMI, ipsiversive OTR is invariable, but abnormalities of oVEMPs and cVEMPs were much less common and mostly dissociated even in the patients with abnormal results. This discrepancy in otolithic dysfunction suggests different anatomical substrates and/or dissimilar reciprocal modulation for processing of each otolithic signal in central vestibular structures located in the dorsolateral medulla.