The Natural History of Radiographically Defined Vertebrobasilar Nonsaccular Intracranial Aneurysms

BACKGROUND

Vertebrobasilar nonsaccular intracranial aneurysms (VBNIA) are characterized by dilatation, elongation, and tortuosity of the vertebrobasilar system.

METHODS

The medical records and imaging of patients with vertebrobasilar fusiform aneurysms or dolichoectasia between 1989 and 2001 were reviewed. Prospective follow-up was obtained.

RESULTS

One hundred and fifty-nine patients were identified (74% male) with 719 patient years of follow-up. Presenting events included: hemorrhage (3%), ischemia (28%), and compression (22%). The remainder were incidental. The 1-, 5-, and 10-year risk of cerebral infarction (CI) due toVBNIA is 2.7, 11.3, and 15.9% respectively. The risk of recurrent CI is 6.7% per patient year. Median survival was 7.8 years and death was most commonly due to ischemia.

CONCLUSIONS

VBNIA are more common in men and typically present in the 6-7th decade. Recurrent CI is more common than hemorrhage risk.

Diffusion-Weighted Magnetic Resonance Imaging in Symptomatic Vertebrobasilar Atherosclerosis and Dissection

BACKGROUND

Acute multiple brain infarction (AMBI) pattern on diffusion-weighted imaging (DWI) is associated with arterial and cardiac sources of embolism. The DWI characteristics of patients with stroke due to vertebrobasilar arterial dissection and atherosclerotic disease have not been reported in detail.

OBJECTIVE

To describe the DWI stroke patterns in patients with posterior circulation occlusive disease to determine mechanisms of ischemia.

DESIGN

Retrospective analysis of infarct patterns in patients with symptomatic vertebrobasilar disease.

SETTING

Large community-based teaching hospital.

PATIENTS

Patients admitted with stroke due to vertebrobasilar disease were identified retrospectively. Patients were included if DWI was obtained within 7 days of symptom onset.

MAIN OUTCOME MEASURE

Infarct patterns were analyzed according to established templates of vascular territories.

RESULTS

Eleven patients with vertebral dissection and 39 patients with atherothrombosis were identified. An AMBI pattern was present in 8 (72%) of 11 patients with arterial dissections and 25 (64%) of 39 patients with atherosclerotic disease (P = .48). Distal embolism to the terminal branches of the basilar artery occurred with equal frequency in both groups and was found in half of all cases. Isolated thalamic infarction did not occur. Pontine infarction was noted in 2 (18%) of 11 patients with dissections and 18 (46%) of 39 patients with atherosclerosis (P = .09). Cerebellar border zone involvement was found in 14 (36%) of 39 patients with atherosclerosis and 4 (37%) of 11 patients with dissections (P = .6).

CONCLUSIONS

Large arterial disease is frequently associated with AMBI in the posterior circulation. The incidence of AMBI was comparable to that reported in the anterior circulation. This DWI study supports the importance of embolism as the main mechanism of infarction in patients with vertebrobasilar occlusive disease. On the basis of our experience, large-vessel vertebrobasilar disease rarely causes isolated small-vessel thalamic infarction.

Postpartum cerebellar infarction and haemolysis, elevated liver enzymes, low platelet (HELLP) syndrome

Pregnancy is considered to be a hypercoagulable state per se with an increased risk for cerebrovascular events, however cerebellar infarction has been rarely described in pregnant women. A nulliparous pre-eclamptic woman at 25 weeks' gestation was submitted to an echocardiographic exam that showed an impaired cardiac structure and function. After 2 h, the patient underwent caesarean section for diagnosis of haemolysis, elevated liver enzymes, low platelet (HELLP) syndrome. Afterwards her platelet count raised, and eight days later she developed nystagmus, ataxia, dysmetria and motor deficit in the right limbs and sensory impairment in the right side of the face and in the left limbs. Cerebral magnetic resonance imaging (MRI) demonstrated a right cerebellar and median posterior bulbar infarction. Colour-coded sonography of cerebral vessels showed an occlusion of the right vertebral artery. Coagulation pattern analysis evidenced double heterozygosis of the methylenetetrahydrofolate reductase (MTHFR) gene and single mutation of the prothrombin gene. This case report gives evidence of the importance of considering the different risk factors involved in stroke occurrence during pregnancy.

The mechanism of ischemic stroke in patients with dolichoectatic basilar artery

Basilar artery dolichoectesia (BD) may cause brainstem ischemia by multiple mechanisms, including thrombosis, embolism, occlusion of deep penetrating arteries. The objective of this study was to determine and characterize clinical, imaging findings and hemodynamic mechanisms in patients with cerebrovascular event associated with BD and compare these data with those for patients with BD who did not have stroke. We studied 29 consecutive stroke, two transient ischemic attack (TIA) patients with BD who have been admitted to our stroke unit. We sought the diameter of ectasia, height of the bifurcation, lateral displacement, shape deformities, and blood flow velocity of the basilar artery (BA) by transcranial Doppler. Imaging and hemodynamic findings were compared with those found in a group of 18 patients without stroke or TIA. The main infarct localization was pons, eight (28%) with restricted single lesion, 10 (32%) with multiple lesions involving thalamus, midbrain, posterior cerebral artery (PCA) territory. Patients with BD were more probably to have had stroke fitting a clinical and imaging patterns of multiple infarcts than those with restricted infarct in territories supplied by branches of the BA (60% vs. 40%). Hypertension and atherosclerotic changes of the posterior circulation were more frequent in patients with stroke than those without (P = 0.004 and P = 0.028, respectively), whilst the incidence of other vascular risk factors were not significantly different in two groups. Patients with stroke/TIA had more often low blood flow velocity but not significant in the BA when compared with those for BD patients without cerebrovascular event (71% vs. 39%; P = 0.1). Reduced blood flow velocity in the BA was correlated significantly with distal lesions involving thalamus, midbrain and PCA territory rather than those located in the territory supplied by branches of the BA (P = 0.02). In conclusion, it seems probably that BD may cause vertebrobasilar system ischemia by multiple mechanisms, especially reduced blood flow in the BA and atheromatous changes in the vertebrobasilar system may precipitate thromboembolic stroke.

Bilateral paramedian midbrain infarct: an uncommon variant of the "top of the basilar" syndrome

Occlusion of the rostral portion of the basilar artery can result in ischaemia of the midbrain and thalami, as well as of the temporal and occipital lobes. The so called "top of the basilar" syndrome manifests clinically as numerous combinations of abnormalities of alertness, sleep-wake cycle, and behaviour and oculomotor or pupillomotor functions. A 67 year old man presented with bilateral internuclear ophthalmoplegia, rubral tremor, and daytime somnolence. He was awake during the night and mostly agitated and aggressive. An ischaemic lesion was visible on the magnetic resonance (MR) image in the central portion of the midbrain just ventral to the aqueduct, clearly affecting the paramedian structures bilaterally. MR angiographic images demonstrated a hypoplastic basilar artery ending in both superior cerebellar arteries. Both posterior cerebral arteries were seen to arise from the corresponding internal carotid arteries via the posterior communicating branches. This unique case of an acute bilateral paramedian infarct represents a highly uncommon variant of the "top of the basilar" syndrome and was due to the affected ischaemic territory--that is, the "distal field" of the variant basilar artery.

Large artery ischaemic stroke in severe acute respiratory syndrome (SARS)

Of the 206 patients who contracted Severe Acute Respiratory Syndrome (SARS) in Singapore five developed large artery cerebral infarctions. Four patients were critically-ill and three died. Intravenous immunoglobulin was given to three patients. An increased incidence of deep venous thrombosis and pulmonary embolism was also observed among the critically-ill patients. We believe our experience warrants an increased vigilance against stroke and other thrombotic complications among critically-ill SARS patients in future outbreaks, especially if treatment such as intravenous immunoglobulin, that increases pro-thrombotic tendency, is contemplated.

High-resolution MRI identifies basilar artery plaques in paramedian pontine infarct

Paramedian pontine infarct (PPI) is usually attributed to basilar artery (BA) atherosclerosis. However, this hypothesis has thus far been supported only by post-mortem studies. The authors show that high-resolution MRI is a promising method that can detect BA plaques in patients with PPI at or near the origin of the penetrating artery, whereas MR angiograms may appear normal.

Sudden deafness in vertebrobasilar ischemia: clinical features, vascular topographical patterns and long-term outcome

BACKGROUND AND PURPOSE

The aim of this study is to document the clinical features and natural history of sudden deafness associated with vertebrobasilar ischemia (VBI) and to describe the vascular topographic patterns of ischemic lesions on brain MRI associated with sudden deafness based on data collected from a prospective acute stroke registry.

METHODS

From 364 consecutive cases of VBI diagnosed by clinical features and brain MRI between January 2000 and September 2003, 29 patients were identified as having sudden deafness as a symptom of VBI.

RESULTS

In our series, the incidence of sudden deafness following VBI is 8.0% (29/364). Hearing loss occurred unilaterally (n=27) or bilaterally (n=2). All but one had vertigo as an associated symptom. Nine patients (31%) presented with an isolated audiovestibular loss initially and subsequently had delayed neurological deficits. Nearly a half of patients (14/29: 48%) showed cochlear features of hearing loss. Seventeen (81%) of 21 patients who were followed for at least 1 year after onset of sudden deafness had a recovery of hearing partially (n=10) or completely (n=7). The improvement rate of hearing loss in patients with profound hearing loss was significantly lower than that in patients with less than profound hearing loss (40% vs. 89%, P<0.01). In addition to infarction in the territory of anterior inferior cerebellar artery (n=23), cerebellar infarction in the territory of the medial branch of posterior inferior cerebellar artery (n=4) or an isolated brainstem infarction (n=2) was also associated with sudden deafness.

CONCLUSION

An isolated sudden deafness with cochlear audiometric features can be the initial presentation of VBI. Sudden deafness due to VBI often has a good outcome. There is topographic heterogeneity of ischemic lesions on brain MRI in patients with sudden deafness due to VBI.

Cerebellar infarcts: key features

Cerebellar infarctions often go unrecognized and misdiagnosed. Easily confused with peripheral vestibular system dysfunction, physicians often miss the cardinal symptoms of dizziness and an abnormal gait. If not treated appropriately and quickly, cerebellar infarcts can lead to coma and death. This review discusses the key features of cerebellar infarction, including the anatomical origination and clinical symptomology of the infarcts. Evaluation recommendations include neuroimaging analysis, which can help clarify the etiology and aid in making therapeutic decisions. Management of patients with cerebellar infarcts is similar to that of patients with posterior circulation ischemia. Antithrombotic drugs, thrombolytics, surgery, and angioplasty/stenting are options.

Enlarging vertebrobasilar nonsaccular intracranial aneurysms: frequency, predictors, and clinical outcome of growth

Object. Vertebrobasilar nonsaccular intracranial aneurysms (NIAs) are characterized by elongation, dilation, and tortuosity of the vertebrobasilar arteries. The goal of this study was to define the frequency, predictors, and clinical outcome of the enlargement of vertebrobasilar NIAs.

Methods. Patients with vertebrobasilar fusiform or dolichoectatic aneurysms demonstrated on imaging studies between 1989 and 2001 were identified. In particular, patients who had undergone serial imaging were included in this study and their medical records were retrospectively reviewed. Prospective information was collected from medical records or death certificates when available. Both initial and serial imaging studies were reviewed. The authors defined NIA enlargement as a change in lesion diameter greater than 2 mm or noted on the neuroradiologist's report. A Cox proportional hazards regression was used to model time from diagnosis of the vertebrobasilar NIA to the first documented enlargement as a function of various predictors. The Kaplan-Meier method was used to study patient death as a function of aneurysm growth.

Of the 159 patients with a diagnosis of vertebrobasilar NIA, 52 had undergone serial imaging studies including 25 patients with aneurysm enlargement. Lesion growth significantly correlated with symptomatic compression at the initial diagnosis (p = 0.0028), lesion type (p < 0.001), and the initial maximal lesion diameter (median 15 mm in patients whose aneurysm enlarged compared with median 8 mm in patients whose aneurysm did not enlarge; p < 0.001). The mortality rate was 5.7 times higher in patients with aneurysm growth than in those with no enlargement after adjustment for patient age (p = 0.002).

Conclusions. Forty-eight percent of vertebrobasilar NIAs demonstrated on serial imaging enlarged, and this growth was associated with significant morbidity and death. Significant risk factors for aneurysm enlargement included symptomatic compression at the initial diagnosis, transitional or fusiform vertebrobasilar NIAs, and initial lesion diameter. Further studies are necessary to determine appropriate treatments of this disease entity once enlargement has been predicted or occurs.

[Alarming symptoms in vertebrobasilar circulatory disorders. Part I]

Dizziness and vertigo--like headache--are the most common complaints which leads patients to visit the doctor. In spite of the headache--which may be primary (e.g. migraine) or symptomatic--dizziness and vertigo do not appear to be a separate nosologic entity but rather the symptoms of several neurological disorders. For differential diagnosis, interdisciplinary thinking and activity is needed because the vestibular, neurological and psychiatric disorders might have a common role in the development of symptoms and further overlapping can also occur. The vascular disorders of the vertebrobasilar system are discussed in detail in this review. The importance, occurrence and causes of vertigo as a warning symptom is in the focus. The author draws attention to life-threatening conditions with acute onset in cases of the posterior scale ischemia and emphasizes the importance of the correct and early diagnosis. The author tries to clear up the nihilistic aspect in treating of stroke and stresses the necessity of thrombolysis and interventional radiological procedures which may be the only chance for the recovery of the patients. The pharmacological prevention of recurrent vascular events is also important and obligatory for the clinicians.

Atherosclerotic occlusive extracranial vertebral artery disease: indications for intervention, endovascular techniques, short-term and long-term results

BACKGROUND

Atherosclerotic occlusive disease of the vertebral artery (VA) affects a significant proportion of patients with cerebrovascular disease and can cause significant morbidity and mortality despite maximal medical therapy. Careful selection of both symptomatic and asymptomatic patients for intervention based on neurological symptoms, as well as anatomical and hemodynamic considerations, is essential.

METHODS

To achieve proper results with angioplasty and stenting, standard endovascular techniques are modified for the unique anatomical considerations of the VA. Several technical nuances are described here to aid in the endoluminal revascularization of the VA.

RESULTS

Technical success (<50% residual diameter stenosis) rates ranging from 94 to 98% and low rates of periprocedural complications have been achieved with VA angioplasty and stenting in select series with angiographic follow-up. The long-term success in those series is limited by the high (10-43%) rate of recurrent stenosis. Proper placement of the stent can reduce the risk of periprocedural complications and restenosis. In-stent stenosis appears most commonly during the first 6-12 months after stent placement, but does not appear to correlate with return of neurological symptoms. We believe the high rate of recurrent stenosis makes follow-up angiography essential, especially in the first 12 months after the procedure.

CONCLUSION

Endovascular VA angioplasty with stent placement provides an innovative approach to treat a difficult clinical entity. Evolving therapies, including drug-eluting stents or bioresorbable stents, may prove to provide better long-term results.

Sudden deafness with vertigo as a sole manifestation of anterior inferior cerebellar artery infarction

Sudden deafness without associated neurological symptoms and signs is typically attributed to a viral inflammation of the labyrinth. Although sudden deafness occurs with anterior inferior cerebellar artery (AICA) infarction, the deafness is usually associated with other brainstem or cerebellum signs such as crossed sensory loss, lateral gaze palsy, facial palsy, Horner syndrome or cerebellar dysmetria. An 84-year-old woman suddenly developed right-sided tinnitus, hearing loss, vertigo and vomiting. Audiometry and electronystagmography documented absent auditory and vestibular function on the right side. T2-weighted and diffusion-weighted MRI showed a tiny infarct in the right lateral inferior pontine tegmentum. AICA occlusion can cause sudden deafness and vertigo without brainstem or cerebellar signs.

[Locked-in syndrome due to a vertebral dissection and therapeutic options with intraarterial fibrinolysis in acute phase]

INTRODUCTION

Dissection of vertebral artery is an unusual pathology but sometimes is the cause of stroke in young patients. Since last years, and with the rise of some chiropractic technics, some authors have related these ones with the dissection of vertebral artery.

CASE REPORT

We show a case of a 37 years old woman that after a chiropractic session began symptoms of posterior circulation dysfunction as decrease level of sense, tetraparesis and alteration of cranial nerves. The arteriography confirmed the existence of a vertebral dissection of V2 portion and thrombosis of basilar and contralateral vertebral arteries. Intraarterial fibrinolysis was performed with complete recanalization of the artery. Although this, the patient had parenchimal lesions in pons, cerebellum and territory of posterior cerebral artery that produced a locked-in syndrome. All the complementary exams were normal.

DISCUSSION

We discuss the relationship between cervical manipulation as an aetiology of vertebral dissection, locked-in syndrome and therapeutic options in these patients

Les méningiomes rachidiens extraduraux : Données IRM à propos de deux observations

Spinal extradural meningiomas are rare and may be easily confused with malignant neoplasms. We report two unusual cases of epidural spinal meningioma one within the left C6-C7 foramen and the other within the left posterolateral epidural space at the T3-T4 level. Low signal intensity of the tumor on T2-wi, thickening and enhancement of the dura with only the possibility of bone erosion are the most characteristic MR findings.

Clinical and radiological predictors of recanalisation and outcome of 40 patients with acute basilar artery occlusion treated with intra-arterial thrombolysis

OBJECTIVE

To define predictors of recanalisation and clinical outcome of patients with acute basilar artery occlusions treated with local intra-arterial thrombolysis (IAT).

METHODS

Vascular risk factors, severity of the neurological deficit graded by the National Institutes of Health stroke scale (NIHSS), and radiological findings were recorded at presentation. Outcome was measured using the modified Rankin scale (mRS) three months later and categorised as favourable (mRS 0-2), poor (mRS 3-5), or death (mRS 6).

RESULTS

40 patients were studied. Median NIHSS on admission was 18. Mean time from symptom onset to treatment was 5.5 hours (range 2.3 to 11). Outcome was favourable in 14 patients (35%) and poor in nine (23%); 17 (42%) died. There were two symptomatic cerebral haemorrhages (5%). Recanalisation of the basilar artery was achieved in 32 patients (80%); it was complete (TIMI grade 3) in 20% and partial (TIMI grade 2) in 60%. In multivariate logistic regression analysis, low NIHSS score on admission (p = 0.002) and vessel recanalisation (p = 0.005) were independent predictors of favourable outcome. Recanalisation occurred more often with treatment within six hours of symptom onset (p = 0.003) and when admission computed tomography showed a hyperdense basilar artery sign (p = 0.007). In a univariate model, quadriplegia (p = 0.002) and coma (p = 0.004) were associated with a poor outcome or death.

CONCLUSIONS

Low baseline NIHSS on admission and recanalisation of basilar artery occlusions predict a favourable outcome after intra-arterial thrombolysis. Early initiation of IAT and the presence of a hyperdense basilar artery sign on CT were associated with a higher likelihood of recanalisation.

Severe bruxism following basal ganglia infarcts: insights into pathophysiology

Bruxism characterized by clenching and grinding of teeth can lead to toothwear, headaches and depression. While bruxism has been associated with a number of neurological diseases, it has not been highlighted following cerebral infarction. An elderly man presented with an acute onset of tooth grinding and jaw clenching associated with dysarthria. His bruxism was worse during the day and resolved during sleep. He had frequent jaw aches, headaches and swallowing difficulty. Examination demonstrated the presence of dysarthria with jaw clenching and tooth grinding, producing persistent high pitch and loud squeaky sounds. A magnetic resonance imaging and angiography examination revealed a recent infarct in the right thalamus. In addition, chronic lacunar infarcts were present in the bilateral caudate nuclei with severe basilar artery stenosis. He was successfully treated with botulinum toxin. We discuss the pathophysiologic mechanisms of bruxism associated with basal ganglia infarcts. Dysfunction of the efferent and/or afferent thalamic or striatopallidal tracts may play a role in bruxism. Early recognition of bruxism following stroke could reduce unnecessary suffering since the condition can be effectively treated.