Pure motor hemiparesis in a case of vertebrobasilar arterial ectasia

Usefulness of vertebrobasilar artery radiological finding as a predictive and prognostic factor for sudden sensorineural hearing loss

OBJECTIVE

The association between sudden sensorineural hearing loss (SSNHL) and radiological findings of the vertebrobasilar artery is not well-known and little research has been done. We hypothesized that the radiological features of the vertebrobasilar artery contribute to the incidence and prognosis of SSNHL.

METHODS

We retrospectively enrolled patients diagnosed with unilateral SSNHL (SSNHL group) and those with acute vestibular neuritis (AVN; control group) in our hospital. All patients underwent magnetic resonance imaging and computed tomography. We measured the following parameters on the radiological images: basilar artery diameter, direction and distance of basilar artery deviation, direction and distance of vertebral artery deviation, and incidence of vertebral artery obstruction. Pure tone audiometry (PTA) was performed in all patients. Follow up PTA between 1 week and 1 month after treatment was performed in the SSNHL group.

RESULTS

A total of 244 SSNHL patients and 62 AVN patients were included in the analysis. Age, body mass index, and basilar artery diameter were found to be significantly associated with SSNHL. In the SSNHL group, patients were divided into three subgroups based on the consistency between the basilar artery deviation site and disease site. No significant difference was noted in initial PTA, final PTA, PTA recovery, and symptom improvement among the three groups. In case of the basilar artery, when the deviation and disease sites were in the opposite direction and the basilar artery diameter was >3.5 mm, diameter of basilar artery was positively correlated with PTA recovery.

CONCLUSIONS

The strength of this study is that radiological evaluation of the vertebrobasilar artery was performed. Further research on the association between SSNHL and radiological features of the vertebrobasilar artery should be conducted to emphasize the importance of vascular assessment in SSNHL.

The effect of microvascular decompression for hemifacial spasm caused by vertebrobasilar dolichoectasia

Objective

Hemifacial spasm (HFS) caused by vertebrobasilar dolichoectasia (VBD) is very rare, and in theses cases, it is difficult to decompress the nerve from its vascular compression. The objective of this study was to investigate the outcome of microvascular decompression (MVD) for HFS caused by VBD.

Methods

There were 10 patients of HFS caused by VBD at our hospital between September 1978 and September 2008. We evaluated magnetic resonance angiography (MRA) and time of flight magnetic resonance imaginge (TOF MRI) findings using the criteria for VBD. We compared the clinical outcomes of MVD for the 10 patients with VBD with the overall outcomes of the total 2058 MVDs performed for HFS.

Results

The results of MVD for HFS caused by VBD were successful in 90.9% of cases. The postoperative complication rate in VBD was 45.5%. Offending vessels in patients with VBD were identified visually during surgery. Adverse effects after MVD were found in 4 patients. We found that the diameter of VBD was significantly greater in patients with complications than in those with no complications (p=0.028).

Conclusion

Our data shows that MVD may be a good treatment modality for HFS caused by VBD but care must be taken to avoid adverse effects from the procedure. It is important to detach the dolichoectatic artery from its surrounding structures sufficiently to allow it to be easily movable. In addition, attempts should be made to lessen the retraction of the cerebellum during release of the dolichoectatic artery.

Microvascular Decompression in the Treatment of Trigeminal Neuralgia Caused by Vertebrobasilar Ectasia

BACKGROUND

Vertebrobasilar ectasia (VBE) is a rare cause of trigeminal neuralgia (TN). It occurs in about 2% of all patients.

OBJECTIVE

This study reviewed the clinical features, radiological concomitants, and surgical findings of VBE and evaluate the microsurgical decompression procedure as a surgical line of treatment of the associated TN.

METHODS

Ten patients with TN caused by VBE and treated by microvascular decompression are the subject of this study. The study consisted of 6 men and 4 women with a mean age of 54 years. The mean duration of symptoms was 4.5 years. TN was the only symptom in 6 patients; it was associated with hemifacial spasm in 4. Arterial hypertension was present in 6 patients. Multiplanar high-resolution magnetic resonance imaging showed the accurate location and course of the ectatic vessel. Magnetic resonance angiography and digital subtraction angiography confirmed the diagnosis. Surgery demonstrated fifth nerve compression by an ectatic and tortuous vertebrobasilar artery in all cases and seventh nerve compression in 4 cases. Teflon felt was placed between the ectatic artery and compressed nerves.

RESULTS

There was complete resolution of TN in 8 patients (80%) and hemifacial spasm in 3 (75%) without medication. Four of 6 hypertensive patients (66.7%) achieved normotension without medication. There was no recurrence of symptoms in the mean follow-up period of 7.8 years.

CONCLUSION

Microvascular decompression is recommended for the treatment of TN caused by VBE if medical treatment has failed, if the patient is suitable for general anesthesia, and if there is evidence of vascular compression of the trigeminal nerve on magnetic resonance imaging.

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.

Cervicomedullary junction compression caused by vertebral artery dolichoectasia and requiring surgical treatment. Case report

A case of progressive brainstem syndrome secondary to vertebral artery (VA) dolichoectasia is reported. The patient presented with partial bilateral abduction paralysis, which progressed to quadriparesis, ataxia, and areflexia. The initial diagnosis was stroke, but because of the patient's deterioration, a diagnosis of Miller-Fisher syndrome was made. Neuroimages obtained at that time revealed an ectatic left VA with minimal cervicomedullary compression. The patient continued to deteriorate despite medical management. Follow-up imaging demonstrated worsened cervicomedullary compression. An emergency posterior fossa neurovascular decompression was performed using a Gore-Tex sling and resulted in mild neurological improvement. This case emphasizes that early recognition and surgical intervention to prevent progressive neurological sequelae are crucial in symptomatic VA dolichoectasia.

Brain-stem compression in vertebrobasilar dolichoectasia. A multimodal electrophysiological study

OBJECTIVE

To evaluate the effects of mechanical compression of the brain-stem in patients with vertebrobasilar dolichoectasia (VBD).

METHODS

In the framework of a prospective, observational study that collected clinical and laboratory data in patients with VBD, we studied 20 patients with compression of the brain-stem due to ectatic, tortuous basilar or vertebral arteries. Patients with cerebral lesions other than small lacunae in the white matter of the cerebral hemispheres were excluded from the study. Patients underwent vestibular and auditory function testing, including brain-stem auditory evoked potentials (BAEPs), blink reflex (BR), somatosensory evoked potentials (SEPs), and motor evoked potentials (MEPs).

RESULTS

Almost all of the patients complained of auditory or vestibular symptoms and none had symptoms or signs of impairment of long tracts or the facial and trigeminal nerves. The most consistent findings were BR abnormalities with prolongation of ipsilateral R1 latency in cases of compression of the pons (10/16) and prolongation of the R2 and R2c latencies with compression of the medulla oblongata (5/15). Subclinical impairment of corticospinal pathways was found in 13 out of 25 instances of compression, and this was more frequent with compression of the pons. Abnormal BAEPs or SEPs were less frequently encountered, and only in cases with compression of the pons.

CONCLUSIONS

Neurovascular compression of the brain-stem, even with severe distortion, is seldom associated with overt clinical signs, whereas subclinical dysfunctions are relatively frequent. The central pathways of the BR and the corticospinal pathways are more susceptible to compression than acoustic and sensory pathways. BR, MEP and BAEP data provide a functional evaluation of the brain-stem and some cranial nerves, which is lacking in imaging studies. Functional investigations may be useful in the long-term management of these patients, since VBD may be progressive and surgical correction may be required at some stage.

Posterior circulation infarcts in patients with vertebrobasilar dolichoectasia

BACKGROUND AND PURPOSE

Vertebrobasilar dolichoectasia (VBD) may produce symptoms by direct compression of cranial nerves or the brain stem, by obstructive hydrocephalus, or by ischemia in the vertebrobasilar arterial territory. This study was undertaken to examine and characterize clinical and imaging findings in patients with stroke associated with VBD and compare these data with those for patients with VBD who did not have a stroke.

METHODS

We studied 40 consecutive stroke patients with associated VBD. All were evaluated by CT scan (n=9), MRI (n=6), or both (n=25). The diameter of the basilar artery (BA), height of bifurcation, and transverse position were evaluated. Clinical and imaging findings were compared with those found in a group of 40 VBD patients without stroke.

RESULTS

More than half of the patients (24 of 40) had infratentorial infarcts, located mainly in the midpons. Sixteen patients had supratentorial lesions localized in the thalamus (n=8) or in the superficial arterial territory of the posterior cerebral artery (PCA; n=8). The diameter and height of the bifurcation of the BA were correlated with the location of the lesion (PCA territory versus BA territory), in that severe ectasia and vertical elongation of the BA were significantly more often observed in patients with infarcts in PCA territory than in patients with infarcts in territories supplied by branches of the BA. Comparison of VBD patients with and without stroke showed that the incidence of arterial hypertension and the degree of ectasia and lateral displacement of the BA were not significantly different in the two groups. Patients with stroke more often had atherosclerotic changes of the posterior circulation (P=.0006) and a higher degree of vertical elongation of the BA (P=.025).

CONCLUSIONS

In patients with VBD, superimposed atheromatous changes of the posterior circulation may have an important role in precipitating ischemia. However, other factors related to the severity of the dolichoectasia also favor ischemia and in some cases are the only factors responsible.

[Basilar ectasia and stroke: imaging features in 21 cases]

Ectasia of the basilar artery (EB) may cause different clinical manifestations, and its analysis by imaging methods is fundamental. We tried to analyse radiological aspects in 21 patients with stroke and EB. In all of them, diagnosis could be done by computed tomography. However, magnetic resonance was the most complete diagnostic method for the evaluation of the relationship between EB an surrounding structures.

Magnetic resonance imaging of vertebrobasilar ectasia in trigeminal neuralgia

Vertebrobasilar ectasia is a rare cause of typical trigeminal neualgia. In a recently published large series only thirty-one (2%) of 1404 consecutive patients with vascularly determined neuralgia were found to have vertebrobasilar compression. We present three patients with trigeminal neuralgia caused by vertebrobasilar ectasia, who were evaluated with high resolution magnetic resonance imaging (MRI). MRI studies provided accurate information on the anatomical location and course of the ectatic vessel in the cerebellopontine angle and the caused mass effect on the brainstem. With gadolinium-enhancement vascular compression of the trigeminal nerve was demonstrated clearly. Surgery confirmed compression of the fifth nerve by an ectatic and tortuous vertebrobasilar artery in two cases. Following microvascular decompression neither patient experienced further pain. The third patient was treated with a ventriculoperitoneal shunt, as he developed occlusive hydrocephalus caused by the vertebrobasilar dolicho-ectasia. MRI is useful in the evaluation of trigeminal neuralgia as it excludes other aetiologies such as tumour or arteriovenous malformation, but also demonstrates cranial nerve compression by ectatic vertebral arteries.

Auditory and vestibular system findings in patients with vertebrobasilar dolichoectasia

Impairment of the auditory-vestibular system has been reported in patients with vertebrobasilar dolichoectasia (VBD), but little is known about the underlying cause of the symptoms. Auditory testing (pure tone audiometry, auditory brain stem response and stapedius reflex) and vestibular tests (assessment of nystagmus, eye tracking tests, caloric test and rotational test) were performed in 23 patients with auditory-vestibular symptoms and/or cranial nerve impairment associated with VBD. Specific evidence of auditory and/or vestibular system impairment was observed in 19 cases (83%). Among patients with abnormal test findings, 47% had evidence suggesting peripheral impairment, 16% evidence suggesting central dysfunction, and 37% evidence suggesting both peripheral and central dysfunction. Although compression of the vestibulocochlear nerve plays an important role in the genesis of the auditory-vestibular dysfunction in patients with VBD, mechanism such as brain stem-cerebellar ischemia and impaired blood supply to the vestibular labyrinth may be just as important.