Atypical Anterior Spinal Artery Infarction due to Left Vertebral Artery Occlusion Presenting with Bilateral Hand Weakness

Background

Infarct of the anterior spinal artery is the most common subtype of spinal cord infarct, and is characterized by bilateral motor deficits with spinothalamic sensory deficits. We experienced a case with atypical anterior-spinal-artery infarct that presented with bilateral hand weakness but without sensory deficits.

Case Report

A 29-year-old man presented with sudden neck pain and bilateral weakness of the hands. Magnetic resonance imaging (MRI) of the brain did not reveal any lesion. His motor symptoms improved rapidly except for mild weakness in his left wrist and fingers. Magnetic resonance angiography showed proximal occlusion of the left vertebral artery; a spine MRI revealed left cervical cord infarction.

Conclusions

Bilateral or unilateral hand weakness can be the sole symptom of a cervical cord infarct.     

Concurrence of Multifocal Motor Neuropathy and Hashimoto's Thyroiditis

Background

Multifocal motor neuropathy (MMN) is an immune-mediated disorder that is characterized by slowly progressive and asymmetrical weakness, but its pathophysiological mechanism is uncertain. The hypothesis that MMN is an immunological disease has been supported by the proven therapeutic effects of intravenous immunoglobulin and the detection of antiganglioside antibodies in MMN patients. The coexistence of MMN with other immune diseases has been rarely reported.

Case Report

A 37-year-old woman visited our hospital complaining of weakness in both hands. The clinical manifestations coincided well with MMN: predominantly distal upper-limb weakness, asymmetric involvement, a progressive course, absence of sensory symptoms, absence of pyramidal signs, and sparing of the cranial muscles. The electrophysiological findings also supported a diagnosis of MMN, with motor nerve conduction block in the median, ulnar, and radial nerves, without sensory nerve involvement. The patient was simultaneously diagnosed as having Hashimoto''s thyroiditis, which is a well-known immune-mediated disease.

Conclusions

The concurrence of MMN and Hashimoto''s thyroiditis in our patient is significant for understanding the immunological characteristics of the two diseases.     

Right Sensory Alien Hand Phenomenon from a Left Pontine Hemorrhage

Background

Acute onset of a sensory alien hand phenomenon has been observed only from a supratentorial lesion involving the non-dominant hand, mostly from a right posterior cerebral artery infarction. A single acute vascular lesion resulting in a dominant hand sensory alien hand syndrome has not been previously documented.

Case Report

A 78-year old right-handed woman exhibited right sensory alien hand phenomenon from a left pontine hemorrhage. Disturbance of proprioceptive input and visuospatial perception are likely to play a role in manifesting the sign.

Conclusions

Dominant-hand sensory alien hand phenomenon may occur in an acute setting from a left pontine hemorrhage.     

Association of Carotid Intraplaque Hemorrhage and Territorial Acute Infarction in Patients with Acute Neurological Symptoms Using Carotid Magnetization-Prepared Rapid Acquisition with Gradient-Echo

Objective

The purpose of our study was to assess prevalence of carotid intraplaque hemorrhage (IPH) and associations between territorial acute infarction and IPH on magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) in patients with acute neurologic symptoms.

Methods

83 patients with suspected acute neurologic symptoms were evaluated with both brain diffusion weighted imaging (DWI) and carotid MPRAGE sequences. Carotid plaque with high signal intensity on MPRAGE of >200% that of adjacent muscle was categorized as IPH. We analyzed the prevalence of IPH and its correlation with territorial acute infarction.

Results

Of 166 arteries, 39 had a carotid artery plaque. Of these arteries, 26 had carotid artery stenosis less than 50%. In all carotid arteries, MR-depicted IPH was found in 7.2% (12/166). High-signal intensity on DWI was found in 17.5% (29/166). Combined lesion with ipsilateral high-signal intensity on DWI and IPH on carotid MPRAGE sequence was found in 6 lesions (6/166, 3.6%). Of patients with carotid artery plaque, MR-predicted IPH was found in 30.8% (12/39) and match lesions with high-signal intensity on DWI and MPRAGE was found in 15.4% (6/39). MR-predicted IPH was significantly higher prevalence in high-grade stenosis group (p=0.010). Relative risk between carotid MPRAGE-positive signal and ipsilateral high-signal intensity on DWI in arteries with carotid artery plaques was 6.8 (p=0.010).

Conclusion

Carotid MPRAGE-positive signal in patients was associated with an increased risk of territorial acute infarction as detected objectively by brain DWI. The relative risk of stroke was increased in high-grade stenosis categories.     

Axon loss is an important determinant of weakness in multifocal motor neuropathy

Background

Multifocal motor neuropathy (MMN) is characterised by asymmetrical weakness and muscle atrophy, in the arms more than the legs, without sensory loss. Despite a beneficial response to treatment with intravenous immunoglobulins (IVIg), weakness is slowly progressive. Histopathological studies in MMN revealed features of demyelination and axon loss. It is unknown to what extent demyelination and axon loss contribute to weakness. Unlike demyelination, axon loss has not been studied systematically in MMN.

Aims/Methods

To assess the independent determinants of weakness in MMN, 20 patients with MMN on IVIg treatment were investigated. Using a standardised examination in each patient, muscle strength was determined in 10 muscles. In the innervating nerve of each muscle, axon loss was assessed by concentric needle electromyography, and conduction block or demyelinative slowing by motor nerve conduction studies. Multivariate analysis was used to assess independent determinants of weakness.

Results

Needle electromyography abnormalities compatible with axon loss were found in 61% of all muscles. Axon loss, and not conduction block or demyelinative slowing, was the most significant independent determinant of weakness in corresponding muscles. Furthermore, axon loss and conduction block were independently associated with each other.

Conclusion

Axon loss occurs frequently in MMN and pathogenic mechanisms leading to axonal degeneration may play an important role in the outcome of the neurological deficit in patients with MMN. Therapeutic strategies aimed at prevention and reduction of axon loss, such as early initiation of treatment or additional (neuroprotective) agents, should be considered in the treatment of patients with MMN.     

Medullary Hemorrhage after Ischemic Wallenberg's Syndrome in a Patient with Cavernous Angioma

Background

The main complication of cerebral cavernous angioma is hemorrhage. Ischemic stroke as a complication of cerebral cavernous angioma has rarely been described, and hemorrhage after ischemic Wallenberg''s syndrome has not been reported before.

Case Report

A 45-year-old woman presented with perioral numbness, hoarseness, dysphagia, and worsening of her previous sensory symptoms. The patient had been taking aspirin for 3 years after suffering from ischemic Wallenberg''s syndrome with left paresthesia as a residual symptom. Brain computed tomography revealed an acute medullary hematoma in the previously infarcted area. Follow-up magnetic resonance imaging revealed a cavernous angioma in the right medulla.

Conclusions

We presume that cerebral cavernous angioma was responsible for both the ischemia and the hemorrhage, and we also cautiously speculate that the aspirin contributed to the development of hemorrhage in the previously infarcted area.     

Ischemic Stroke in Takayasu's Arteritis: Lesion Patterns and Possible Mechanisms

Background and Purpose

The purpose of the present study was to use brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) to identify the mechanism of stroke in patients with Takayasu''s arteritis (TA).

Methods

Among a retrospective cohort of 190 TA patients, 21 (3 males and 18 females) with a mean age of 39.9 years (range 15-68 years) who had acute cerebral infarctions were included in lesion pattern analyses. The patients'' characteristics were reviewed, and infarction patterns and the degree of cerebral artery stenosis were evaluated. Ischemic lesions were categorized into five subgroups: cortical border-zone, internal border-zone, large lobar, large deep, and small subcortical infarctions.

Results

In total, 21 ischemic stroke events with relevant ischemic lesions on MRI were observed. The frequencies of the lesion types were as follows: large lobar (n=7, 33.3%), cortical border zone (n=6, 28.6%), internal border zone (n=1, 4.8%), small cortical (n=0, 0%), and large deep (n=7, 33.3%). MRA revealed that 11 patients had intracranial artery stenosis.

Conclusions

Hemodynamic compromise in large-artery stenosis and thromboembolic mechanisms play significant roles in ischemic stroke associated with TA.     

T1 Slope and Cervical Sagittal Alignment on Cervical CT Radiographs of Asymptomatic Persons

Objective

We performed a retrospective analysis of medical records and radiographic images of patients who never underwent spinal treatment including diagnosis. The objective of this study is to explain the biomechanical and physiologic characteristics of cervical alignment related to thoracic inlet angle including T1 slope changes in each individual.

Methods

We reviewed the cervical CT radiographs of 80 patients who visited ENT outpatient clinic without any symptom, diagnosis and treatment of cervical spine from January 2011 to September 2012. All targeted people were randomized without any prejudice. We assessed the data-T1 slope, Cobb''s angle C2-7, neck tilt, sagittal vertical axis (SVA) C2-7 and thoracic inlet angle by the CT radiographs.

Results

The relationships between each value were analyzed and we concluded that Cobb''s angle C2-7 gets higher as the T1 slope gets higher, while the SVA C2-7 value decreases.

Conclusion

We propose that the T1 slope is background information in deciding how much angle can be made in the cervical spinal angle of surgical lordotic curvature, especially severe cervical deformity.     

Takotsubo Cardiomyopathy Following Cerebral Infarction Involving the Insular Cortex

Background

Takotsubo cardiomyopathy is characterized by clinical features similar to those of acute myocardial ischemia, but without angiographic evidence of obstructive coronary artery disease. We present a patient with takotsubo cardiomyopathy following acute infarction involving the left insular cortex.

Case Report

A 52-year-old man was admitted with acute infarction of the left middle cerebral artery territory and acute chest pain. Acute myocardial infarction was suspected because of elevated serum troponin levels and hypokinesia of the left ventricle on echocardiography. However, a subsequent coronary angiography revealed no stenosis within the coronary arteries or ballooning of the apical left ventricle.

Conclusions

We postulated that catecholamine imbalance due to the insular lesion could be responsible for these interesting features.     

Neuroradiologic and Neurophysiologic Findings of Neuralgic Amyotrophy

Objective

Neuralgic amyotrophy (NA) is a distinct clinical syndrome that is characterized by the acute onset of shoulder and arm pain, weakness, and sensory loss. The purpose of this study was to assess the clinical characteristics of NA and to determine appropriate diagnostic modalities.

Methods

We reviewed the medical and radiologic records of 10 patients diagnosed with NA retrospectively. Neurophysiologic studies were performed in all patients and magnetic resonance neurography was performed in the last three patients.

Results

A total of 10 patients were enrolled in our study. All patients had clinical findings compatible with NA. The most common clinical presentation was severe shoulder pain and weakness in seven patients (70%). Neurophysiologic study results were abnormal in all patients. Brachial plexus magnetic resonance neurography showed that the affected brachial plexus showed a thickened and hyper-intense trunk. All patients were managed conservatively with analgesics and physical therapy. The pain and paralysis of all patients improved clinically within 6 months of the initiation of treatment.

Conclusion

NA is a rare disease but the symptoms of NA can mimic those of other diseases. Neurophysiologic studies and magnetic resonance neurography are extremely useful tools for the diagnosis of NA.     

The Etiological Spectrum of Acute Sensory Myelitis

Background and Purpose

Acute myelitis patients exhibiting only sensory deficits upon initial presentation are not commonly encountered in clinical practice, but they definitely exist. Since acute sensory myelitis has not been investigated previously, this study evaluated the etiological spectrum of the condition with the aim of describing the clinical characteristics thereof.

Methods

Patients with acute myelitis who presented at the Ewha Womans University Medical Center (during 1999-2012) and the National Cancer Center (during 2005-2014) with only sensory symptoms as first clinical features were enrolled in this study. Their medical records, electrophysiological and laboratory data, and MRI findings were analyzed retrospectively.

Results

Of a total of 341 acute myelitis patients, 52 (15%) were identified as having acute sensory myelitis. The male-to-female ratio of these patients was 35:17, and their age at the onset of the condition was 41.7±10.5 years (mean±SD; range, 24-72 years). Acute sensory myelitis developed in patients with multiple sclerosis (MS; 14%), neuromyelitis optica spectrum disorder (NMOSD; 17%), and acute myelitis associated with concurrent systemic diseases including Behçet''s disease and cancer (6%). Despite detailed evaluation, the etiology of 33 patients with acute myelitis could not be determined. Longitudinally extensive transverse myelitis on spinal MRI and progression of the sensory level were observed most commonly in NMOSD patients (89% and 78%, respectively); however, these patients did not exhibit sensory dissociation. Residual negative sensory symptoms were observed more frequently in NMOSD patients (33%) than in those with acute myelitis of unknown cause (24%) or MS (14%). During the long-term follow-up (4.7±2.7 years) of patients who did not undergo maintenance immunotherapy, a monophasic clinical course was common in those with acute myelitis of unknown cause (76%), but not in NMOSD or MS patients.

Conclusions

Accurate identification of the diverse nature of acute sensory myelitis may assist in patient care.     

Brain Activation Evoked by Sensory Stimulation in Patients with Spinal Cord Injury : Functional Magnetic Resonance Imaging Correlations with Clinical Features

Objective

The purpose of this study is to determine whether the changes of contralateral sensorimotor cortical activation on functional magnetic resonance imaging (fMRI) can predict the neurological outcome among spinal cord injury (SCI) patients when the great toes are stimulated without notice.

Methods

This study enrolled a total of 49 patients with SCI and investigated each patient''s preoperative fMRI, postoperative fMRI, American Spinal Injury Association (ASIA) score, and neuropathic pain occurrence. Patients were classified into 3 groups according to the change of blood oxygenation level dependent (BOLD) response on perioperative fMRI during proprioceptive stimulation with repetitive passive toe movements : 1) patients with a response of contralateral sensorimotor cortical activation in fMRI were categorized; 2) patients with a response in other regions; and 3) patients with no response. Correlation between the result of fMRI and each parameter was analyzed.

Results

In fMRI data, ASIA score was likely to show greater improvement in patients in group A compared to those belonging to group B or C (p<0.001). No statistical significance was observed between the result of fMRI and neuropathic pain (p=0.709). However, increase in neuropathic pain in response to the signal change of the ipsilateral frontal lobe on fMRI was statistically significant (p=0.030).

Conclusion

When there was change of BOLD response at the contralateral sensorimotor cortex on perioperative fMRI after surgery, relief of neurological symptoms was highly likely for traumatic SCI patients. In addition, development of neuropathic pain was likely to occur when there was change of BOLD response at ipsilateral frontal lobe.     

Emergency Carotid Artery Stent Insertion for Acute ICA Occlusion

Objective

An effective intervention has not yet been established for patients with acute occlusion of the internal carotid artery (ICA). The aim of our study was to investigate the feasibility, safety, and efficacy of emergent stent placement of carotid artery to improve neurologic symptoms and clinical outcome.

Methods

Of 84 consecutive patients with severe ICA stenosis who were admitted to our institution from March 2006 to May 2009, 10 patients with acute ICA occlusion (11.9%) underwent emergency carotid artery stent placement. We reviewed their records for neurologic outcome using the National Institutes of Health Stroke Scale (NIHSS) score, before and at 7 days after stent placement; clinical outcome using the modified Rankin Scale score (mRS) and Glasgow Outcome Scale (GOS); frequency of procedure-related complications; and recurrence rate of ipsilateral ischemic stroke within 90 days.

Results

Carotid lesions were dilated completely in all patients. Median NIHSS scores before emergency stent placement and at 7 days were 16.6 and 6, respectively, showing significant improvement. Eight patients (80%) had favorable outcomes (mRS score 0-2 and GOS 4-5). Complications occurred in two patients (20%): stent insertion failed in one and an intracerebral hemorrhage occurred in the other. Ipsilateral ischemic stroke did not recur within 3 months.

Conclusion

Emergency carotid artery stent placement can improve the 7-day neurologic outcome and the 90-day clinical outcome in selected patients with acute cerebral infarction.     

Outcome Evaluation with Signal Activation of Functional MRI in Spinal Cord Injury

Objective

The authors investigated the changes of cortical sensorimotor activity in functional MRI (fMRI) and functional recovery in spinal cord injury (SCI) patients who had been treated by bone marrow cell transplantation.

Methods

Nineteen patients with SCI were included in this study; ten patients with clinical improvement and nine without. The cortical sensorimotor activations were studied using the proprioceptive stimulation during the fMRI.

Results

Diagnostic accuracy of fMRI with neurological improvement was 70.0% and 44.4% for sensitivity and specificity, respectively. Signal activation in the ipsilateral motor cortex in fMRI was commonly observed in the clinically neurological improved group (p-value=0.002). Signal activation in the contralateral temporal lobe and basal ganglia was more commonly found in the neurological unimproved group (p-value<0.001). Signal activation in other locations was not statistically different.

Conclusion

In patients with SCI, activation patterns of fMRI between patients with neurologic recovery and those without varied. Such plasticity should be considered in evaluating SCI interventions based on behavioral and neurological measurements.     

Migraine with unilateral motor symptoms: a case-control study

Objective

To characterise the clinical features of non‐familial migraine with unilateral motor symptoms (MUMS) and compare these features with those of migraine without weakness.

Methods

24 patients with MUMS and 48 matched controls were identified from a tertiary care headache centre. Using a structured interview, the migraine symptoms of both groups were characterised. Results of previously administered Beck Depression Inventories (BDI), Minnesota Multiphasic Personality Inventories and psychiatric diagnoses were collected, when available, and compared between groups.

Results

9 patients had episodic migraine and 15 had chronic migraine. Patients with MUMS always had weakness involving the arm subjectively, and both arm and leg objectively. A give‐way character was always present. Only 17% of patients with MUMS reported facial weakness; 58% reported persistent interictal weakness; 92% reported sensory symptoms. A rostrocaudal march of sensory and motor symptoms was frequently reported. Weakness was ipsilateral to unilateral headache in two thirds of the patients. Compared with controls, patients with MUMS had had similar pain intensities, but were more likely to report other migrainous symptoms, including allodynia. 38% of patients with MUMS were told they had had a stroke, and 17% believed they had had a stroke despite normal brain imaging. Patients with MUMS reported fewer affective disorders and more adjustment disorders than controls, and had similar BDI scores.

Conclusions

A syndrome of severe migraine with accompanying give‐way weakness is common in tertiary care headache centres. It is accompanied by other neurological symptoms.Migraine has a variety of subtypes, some of which are associated with hemiplegia. Aura is highly variable and is thought to be generated from many areas of the cortex or brain stem. A recent epidemiological study estimated the prevalence of both familial and sporadic hemiplegic migraine in Denmark to be 0.01%.¹ By contrast, Couch et al² reported the rate of hemiplegic symptoms to be 10% in a large tertiary care headache practice. In all, 11 of 78 patients admitted to the Thomas Jefferson University Hospital (Philadelphia, Pennsylvania, USA) for the treatment of headache reported hemiplegic symptoms, and six had hemiparesis on admission.³Of 205 subjects in Fisher''s studies of patients with late‐life migraine accompaniments, 45 had motor weakness.^4,5 All cases were accompanied by visual symptoms, paraesthesias and speech disturbances. Of 22 cases of migraine and cluster headache with limb pain accompanying the headache, six also had recurrent weakness.⁶ Sensorimotor disturbances often accompany chronic pain syndromes. Complex regional pain syndrome is often associated with allodynia, weakness and dystonia.⁷ These symptoms, along with non‐dermatomal sensory loss, have been labelled “psychogenic pseudoneurological dysfunction” by some authors.⁷ Motor impairments correlate with allodynia in complex regional pain syndrome type I.⁸Our study was designed to confirm and further characterise previous observations on motor weakness accompanying migraine headache. We postulated that unilateral motor symptoms are common in patients with migraine in a tertiary care centre, and that their presence may be due to the activation of sensorimotor programme related to the pain and presence of allodynia.     

Zonisamide Changes Unilateral Cortical Excitability in Focal Epilepsy Patients

Background and Purpose

To evaluate changes in cortical excitability induced by zonisamide (ZNS) in focal epilepsy patients.

Methods

Twenty-four drug-naїve focal epilepsy patients (15 males; overall mean age 29.8 years) were enrolled. The transcranial magnetic stimulation parameters obtained using two Magstim 200 stimulators were the resting motor threshold, amplitude of the motor-evoked potential (MEP), cortical silent period, short intracortical inhibition, and intracortical facilitation. These five transcranial magnetic stimulation parameters were measured before and after ZNS, and the findings were compared.

Results

All 24 patients were treated with ZNS monotherapy (200-300 mg/day) for 8-12 weeks. After ZNS, MEP amplitudes decreased (-36.9%) significantly in epileptic hemispheres (paired t-test with Bonferroni''s correction for multiple comparisons, p<0.05), whereas the mean resting motor threshold, cortical silent period, short intracortical inhibition, and intracortical facilitation were unchanged (p>0.05). ZNS did not affect cortical excitability in nonepileptic hemispheres.

Conclusions

These findings suggest that ZNS decreases cortical excitability only in the epileptic hemispheres of focal epilepsy patients. MEP amplitudes may be useful for evaluating ZNS-induced changes in cortical excitability.     

Factors Associated with the Success of Trial Spinal Cord Stimulation in Patients with Chronic Pain from Failed Back Surgery Syndrome

Objective

Spinal cord stimulation (SCS) is an effective means of treatment of chronic neuropathic pain from failed back surgery syndrome (FBSS). Because the success of trial stimulation is an essential part of SCS, we investigated factors associated with success of trial stimulation.

Methods

Successful trial stimulation was possible in 26 of 44 patients (63.6%) who underwent insertion of electrodes for the treatment of chronic pain from FBSS. To investigate factors associated with successful trial stimulation, patients were classified into two groups (success and failure in trial). We investigated the following factors : age, sex, predominant pain areas (axial, limb, axial combined with limbs), number of operations, duration of preoperative pain, type of electrode (cylindrical/paddle), predominant type of pain (nociceptive, neuropathic, mixed), degree of sensory loss in painful areas, presence of motor weakness, and preoperative Visual Analogue Scale.

Results

There were no significant differences between the two groups in terms of age, degree of pain, number of operations, and duration of pain (p>0.05). Univariate analysis revealed that the type of electrode and presence of severe sensory deficits were significantly associated with the success of trial stimulation (p<0.05). However, the remaining variable, sex, type of pain, main location of pain, degree of pain duration, degree of sensory loss, and presence of motor weakness, were not associated with the trial success of SCS for FBSS.

Conclusion

Trial stimulation with paddle leads was more successful. If severe sensory deficits occur in the painful dermatomes in FBSS, trial stimulation were less effective.     

Hypoplastic vertebral artery: frequency and associations with ischaemic stroke territory

Background

In patients with posterior inferior cerebellar artery infarction (PICAI) or lateral medullary infarction (LMI), the ipsilateral vertebral artery is often hypoplastic and therefore at an increased risk of ischaemic stroke.

Objective

To investigate the frequency and clinical relevance of hypoplastic vertebral artery (HVA) in patients with ischaemic stroke with or without vertebral artery territory and in normal healthy people.

Methods

529 patients with ischaemic stroke, including vertebral artery territory infarction (LMI or PICAI), were classified according to their stroke location (303 anterior circulation strokes (ACS) and 226 posterior circulation strokes (PCS)) by MRI. The frequency of HVA, defined as a diameter of ⩽2 mm by magnetic resonance angiography, was measured in comparison with 306 normal healthy people.

Results

185 patients (35.2%) from the cohort had HVA (3.4%, bilaterally). Patients with PCS showed a higher rate of HVA than those with ACS (45.6% vs 27.1%, p<0.001). The HVA frequency of those with ACS was similar to that of the normal group (26.5%). Of the 112 patients with vertebral artery territory stroke, 58 (51.8%) had HVA (bilateral HVA in 10), and all of 48 showed ipsilateral HVA territory stroke. In 102 patients with vertebral artery territory stroke, classification of the ipsilateral vertebral artery as hypoplastic (vs dominant or symmetric) tended to predict the involvement of multiple and extensive lesions, and a higher incidence of steno‐occlusion (p<0.001).

Conclusion

HVA is not rare in the normal population, and is frequent in patients with PCS. People with HVA may have a high probability of PCS, with atherosclerotic susceptibility and ipsilateral lesions in the vertebral artery territory.Congenital variations in the arrangement and size of the vertebral arteries are frequently recognised, ranging from asymmetry of both vertebral arteries to severe hypoplasia of one vertebral artery on cerebral angiography. In a pathoanatomical study, hypoplastic vertebral artery (HVA) was defined as a lumen diameter of ⩽2 mm,¹ but there is no consensus on this value.The absence of vertebrobasilar insufficiency symptoms among people with HVA indicates that even marked vertebral artery asymmetry is a normal variation,^2,3,4 and has led to an underestimation of the incidence and clinical relevance of HVA. However, ipsilateral HVA is common in patients with posterior inferior cerebellar artery infarction (PICAI) or lateral medullary infarction (LMI), suggesting that HVA confers an increased probability of ischaemic stroke. Although the relationship between hypoplasia of the vertebral artery or the basilar artery and the risk of posterior circulation ischaemia has been examined,⁵ there have been few reports on the relationship between HVA and territorial ischaemic stroke, to our knowledge.The objectives of this study were to determine the frequency of HVA in normal healthy people and in patients with stroke, and the clinical relevance of HVA in patients with ischaemic stroke with vertebral artery territory.     

Acute Spinal-Cord Ischemia: Evolution of MRI Findings

Background and Purpose

Magnetic resonance (MR) findings in acute spinal-cord ischemia can be summarized as focal cord enlargement and hyperintensities on T2-weighted images and gadolinium enhancement, especially of the central gray matter. However, in analogy with acute brain ischemia, it is to be expected that the findings of MR imaging (MRI) may be normal in the first hours after symptom onset. We evaluated the clinical and MRI findings in a series of patients with acute spinal-cord ischemia, and tested the hypothesis that the development and course of MR abnormalities are predictable.

Methods

Five patients with acute spinal-cord ischemia were admitted to our hospital over a 2-year period. Repeated MRI (1.5 T) was performed in all patients. Clinical data were retrieved from the patients'' charts.

Results

Four women and one man with a median age of 52 years (range, 31-75 years) were admitted. Three patients had anterior spinal artery infarction and two patients had transverse infarctions. All patients underwent spinal MRI within 24 hours; the findings were normal in four of the five patients. After 1-2 days, T2-weighted MRI generally exhibited focal cord enlargement and hyperintensity in all patients, while spinal-cord enhancement appeared after 2-11 days.

Conclusions

Acute spinal-cord ischemia may have a typical course on MRI. MRI findings are usually normal in the acute phase, but spinal cord swelling and T2 abnormality are expected after several days, while gadolinium enhancement appears even later after symptom onset. The sensitivity and specificity of MRI can be increased by repeated MRI in patients suspected of acute spinal-cord ischemia.     

Preoperative Weakness and Demyelination of the Corticospinal Tract in Meningioma Patients : Changes in Diffusion Parameters Using Diffusion Tensor Imaging

Objective

Differentiation of demyelination in white matter from axonal damage can be determined using diffusion tensor imaging (DTI). In this study using meningioma patients an attempt was made to evaluate the relationship between preoperative weakness and the changes of diffusion parameters in the corticospinal tract (CST) using DTI.

Methods

Twenty-six patients with meningioma were enrolled in this study. Eleven of them suffered from objective motor weakness and were classified as Group 1. The remaining 15 patients did not present motor weakness and were classified as Group 2. Fiber tractography and CST diffusion parameters were obtained using DTIStudio. The ratios (lesion side mean value/contralateral side mean value) of CST diffusion parameters were compared with 1.0 as a test value using a one-sample t-test.

Results

In Group 1, fractional anisotropy (FA), tensor trace (TT), and radial diffusivity (RD, λ2 and λ3) of the CST were significantly different between two hemispheres, but axial diffusivity (AD, λ1) of the CST was not significantly different between two hemispheres. In Group 2, FA and λ3 of CST did not differ significantly between the hemispheres. In Group 2, TT, λ1, and λ2 of CST in the ipsilateral hemisphere were significantly higher than those of the unaffected hemisphere. However, the differences were small.

Conclusion

Motor weakness was related to a low FA and high TT resulting from increased RD of the CST fibers. CST diffusion changes in patients with weakness are similar to those for demyelination.