Internal carotid artery bulb width: a novel potential parameter for the prediction of cerebral vascular diseases

OBJECTIVE

To investigate the relationship between the width of the internal carotid artery (ICA) bulb and cerebral vascular diseases including stroke and intracranial aneurysms.

MATERIAL AND METHODS

In total 300 patients who had supra-aortic computed tomography angiography (CTA) were enrolled in this study from 2015 to 2021. The study groups consisted of 100 ischemic stroke patients, 100 patients with intracranial aneurysms, and 100 control subjects. The intracranial aneurysm patient group was divided into two subgroups according to the presence of subarachnoid hemorrhage (SAH). The largest diameters of the ICA C1 (cervical) and C2 (petrous) segments in all individuals were measured bilaterally on CTA images. The ICA diameter ratios of the cases were measured using the formula C1-C2C1. The relationship between the age and ICA vessel analysis was evaluated as well.

RESULTS

The mean ICA bulb width values in the ischemic stroke patient group and the intracranial aneurysm patient group were significantly higher than the control group (p < 0.001). The ICA C1 and C2 segment diameter values and ICA diameter ratio were smaller in the intracranial aneurysm patients with SAH than those who had not (p = 0.7). There was a statistically significant but weak relationship between the age and ICA diameter ratios in all study groups (R-squared value of 0.26, p = 0.03).

CONCLUSION

ICA bulb width is a parameter that can be easily evaluated with neuroimaging modalities and is a successful method that may be used for predicting the risk of ischemic stroke or the presence of an intracranial aneurysm.

Unilateral agenesis of internal carotid artery with interparaclinoid and contralateral carotid-anterior cerebral artery anastomoses diagnosed by magnetic resonance angiography: a case report

PURPOSE

Unilateral agenesis of the internal carotid artery (ICA) is a rare anatomical variant. We identified a case of unilateral ICA agenesis with interparaclinoid and contralateral carotid-ACA anastomoses.

METHODS

A 65-year-old female with a long history of depressive episodes underwent MR imaging including MR angiography at National Hospital Organization Kyushu Medical Center. MR imaging was performed using a 3.0-T MR scanner to rule out vascular Parkinsonism, although drug-induced Parkinsonism was suspected from her medical history.

RESULTS

The proximal left ICA was not visible on MR angiography, and an anterior communicating artery (ACoA) aneurysm was identified. The left middle cerebral artery was supplied from the right ICA via an interparaclinoid anastomosis. This interparaclinoid anastomosis showed no communication with the basilar, posterior communicating, or posterior cerebral arteries. A communicating artery connecting the interparaclinoid anastomosis and anterior cerebral artery (ACA) branched off from the presumed transition point between the interparaclinoid anastomosis and left ICA. Both right and left ophthalmic arteries (OAs) originated from the clinoid segment of the ICA. The communicating artery connecting the interparaclinoid anastomosis and ACA arose proximal to the left OA, and the communicating artery was identified as the carotid-ACA anastomosis.

CONCLUSION

Neuroradiologists, physicians, and neurosurgeons need to be aware of this extremely unusual anatomical variant to determine appropriate treatment strategies in cases of aneurysmal growth or anterior cranial base surgery.

Carotid petrous segment aneurysm presenting as hypoglossal nerve palsy

Aneurysm in the petrous segment of the internal carotid artery is extremely rare, and symptoms are usually derived from compression of neighbor structures such as nerve palsies. Clinical symptoms can be nonspecific and imaging findings are complex, making the diagnosis of this kind of aneurysms extremely challenging. CT angiography is the best diagnostic tool, and treatment options include surgical and endovascular approaches, the latest being preferred. We report an extremely rare case of an aneurysm in the petrous apex presenting with hypoglossal nerve palsy. We document the aneurysm through CT and confirm it using angiography. We also describe the satisfactory management of this rare case. To the best of our knowledge this an extremely rare aneurism presenting with hypoglossal nerve palsy, in which successful interventional management was achieved through a specific and prompt diagnosis.

Skull base ligamentous mineralisation: evaluation using computed tomography and a review of the clinical relevance

Objectives

To determine the frequency, morphologic and demographic characteristics, and clinical relevance of the mineralisation of six skull base ligaments (interclinoid, caroticoclinoid, petrosphenoid, posterior petroclinoid, pterygospinous, and pterygoalar).

Methods

This is a retrospective review of 240 CT scans of the paranasal sinuses (ages 6–80 years). A limited systematic review was performed primarily using Embase and Medline databases.

Results

Ligamentous mineralisation was well delineated on CT and occurred at ≥ 1 location in 58.3% of patients. There was a nonsignificant trend towards a greater incidence with advancing age. The interclinoid and posterior petroclinoid ligaments were most commonly mineralised (22.1% and 18.3%, respectively); the petrosphenoid and pterygoalar ligaments were least frequently mineralised (10.8% and 6.3%, respectively). The mean age of patients with posterior petroclinoid mineralisation was significantly greater than those with interclinoid and petrosphenoid mineralisation and was not seen in patients aged 6–20 years. The literature review highlighted the clinically relevant potential for mineralised ligaments to cause barriers to surgical access (e.g. to the foramen ovale), increase the risk of neurovascular injury during surgery at the skull base (e.g. during anterior clinoidectomy), and predispose to neural impingement.

Conclusions

Skull base ligamentous mineralisation is commonly encountered on CT imaging. Given the potentially significant clinical implications, an understanding of the morphological appearances is of importance to those planning interventions at the skull base. To the authors’ knowledge, this study is the first to comprehensively evaluate such a wide range of skull base ligaments using CT. For some ligaments, the incidence on CT has not been previously described.

[Microsurgical treatment of paraclinoid aneurysms]

Objective: To explore the microsurgical treatment of paraclinoid aneurysms and evaluate its safety and efficacy. Methods: The data of 21 patients with 22 paraclinoid aneurysms receiving craniotomy between Jan. 2010 and Dec. 2017 in Peking University First Hospital were retrospectively analyzed. According to the Barami K classification, 2 aneurysms were type Ⅰa, 6 type Ⅰb,7 typeⅡ,6 type Ⅲa,1 type Ⅳ. Out of the 17 cases of saccular aneurysms, 16 aneurysms were clipped and one aneurysm was trapped following high-flow EC-IC bypass. Out of the 5 cases of blood blister like aneurysms, 2 aneurysms were wrap-clipped, 2 aneurysms were trapped following high-flow EC-IC bypass and 1 aneurysm was trapped following STA-MCA bypass. The patients were reexamined with CT angiography (CTA) or digital subtraction angiography (DSA) and followed up in outpatient or by phone call. Results: Seventeen patients with 18 paraclinoid aneurysms had received aneurysm clipping. Aneurysmal neck remnant was found in 2 cases, parent artery stenosis was found in 2 cases. In all of the four bypass cases, graft artery patency was confirmed and no recurrence of aneurysm was observed. The obliteration rate of the paraclinoid aneurysm was 91%(20/22). Eight cases with preoperative vision defect had recovered to some extent. New vision defect occurred in two cases. At discharge, 12 patients scored with Glasgow outcome scale 5, 6 patients scored 4, 2 patients scored 3, and one patient scored 1. Conclusion: Microsurgical treatment for paraclinoid aneurysm is a safe and effective method with high aneurysm obliteration rate and low aneurysm recurrence rate, and is thus a reasonable and effective complementary method for endovascular treatment.

Pulsatile tinnitus associated with dehiscent internal carotid artery: An irremediable condition?

Dehiscent internal carotid artery (ICA) in the middle ear is a rare condition, with conservative treatment primarily recommended. We report the case of a 63-year-old patient referred to the Ear, Nose, and Throat (ENT) ward for unbearable pulsatile tinnitus. Otoscopy revealed a normal right tympanic membrane, with pulsatile tinnitus but without hearing impairment. Based on imaging studies, including computed tomography (CT) and magnetic resonance imaging (MRI) of the temporal bone, as well as Doppler ultrasound of the internal carotid artery and sigmoid sinus, the diagnosis of ICA canal dehiscence into the tympanic cavity was established, thus excluding the diagnosis of aberrant ICA. Following the patient's own request, we undertook surgical correction, with the technique used described in the report. Immediately postoperatively, the pulsatile tinnitus had disappeared, with no surgical complications noted. At the 9-month follow-up, otoscopy revealed a healthy right tympanic membrane and the patient reported no remaining symptoms.

Perfusion Study for Internal Carotid Artery Trapping of a Traumatic Pseudoaneurysm in an Unconscious Patient

Perfusion study should be preoperatively required for the trapping of an internal carotid artery (ICA) in the traumatic pseudoaneurysm in the petrous ICA. A 23-year-old man was admitted with a semicomatose consciousness after a passenger traffic accident. A fracture on the right petrous apex and a pseudoaneurysm in the right petrous ICA was found in the brain computed tomography (CT) angiogram. The size of aneurysm grew in the catheter angiogram at the 3rd day of trauma. One-day protocol of brain single photon emission CT (SPECT), which the first scan with 20 mCi of technetium-99m-ethyl cysteinate diethylester (^99mTc-ECD) and the second scan with 40 mCi in double dose at 15 minutes during the balloon test occlusion (BTO) at the same day, was done for the perfusion evaluation before trapping the right ICA. Perfusion asymmetry was aggravated of 21% at the post-occlusion scan in the right frontal cortex. So, he got a superficial temporal artery-middle cerebral artery anastomosis and then ICA trapping. After the surgery, he recovered consciousness and went back to his normal life. He has not developed new neurologic symptom for 8 years. Brain SPECT with double-dose injection of ^99mTc-ECD may be a useful tool to be performed with BTO.

Endovascular Management of Long-Segmental Petrocavernous Internal Carotid Artery (Carotid S) Occlusion

Background and Purpose

Long-segmental thrombotic occlusion of the distal internal carotid artery (ICA) sparing the cervical segment proximally and the supraclinoid segment distally, which could be termed ’Carotid S occlusion’, has an unusual clinical presentation. However, endovascular management of this lesion is challenging. The purpose of our study is to report our endovascular treatment clinical experience of the disease.

Methods

From March 2008 to June 2013, we could identify 14 patients (average age: 62.1, median age: 62, range: 50-79) with ‘Carotid S occlusion’, who underwent endovascular recanalization procedures. Patient’s clinical presentations were collected and the imaging findings also analyzed. The technical success rate, 24-hour and follow-up imaging outcome, and the clinical outcome using the 90-day mRS (modified Rankin scale) score were evaluated.

Results

Patients presented with gradually progressing (n = 8), fluctuating (n = 3), transient ischemic attack (n = 2) and stationary (n = 1) symptoms. DWI showed internal and external border-zone lesions in six patients, only internal ICA border-zone lesions in three patients, and only external border-zone lesions in two patients. Underlying distal ICA stenosis was noted in 12 patients. The technical success rate was 92.8% (13/14). Luminal patency was noted in all patients (100%) after 24 hours and in nine of 10 (90%) on long-term follow-up (median: 6.5, average: 15.1, range: 1-39 months). A 90-day, good functional outcome (mRS ≤ 2) was noted in 13 of 14 patients (92.8%).

Conclusions

‘Carotid S occlusion’ usually presented with border-zone infarction and endovascular management of the lesions was feasible. A relatively successful clinical outcome could be achieved after successful revascularization.

Quantitative Magnetic Resonance Angiography in Internal Carotid Artery Occlusion with Primary Collateral Pathway

Background and Purpose

Quantitative magnetic resonance angiography (Q-MRA) enables direct measurement of volume flow rate (VFR) of intracranial arteries. We aimed to evaluate the collateral flows in internal carotid artery (ICA) occlusion with primary collateral pathway via circle of Willis using Q-MRA, and to compare them between patients who recently developed ipsilateral symptomatic ischemia and those who did not.

Methods

Between 2012 and 2014, 505 patients underwent Q-MRA in our institution. Among these, 33 patients who had unilateral ICA occlusion with primary collateral pathway were identified, and grouped into asymptomatic patients, stable patients with chronic infarction, and symptomatic patients with acute/subacute infarction. Mean VFR (mVFR) in intracranial arteries was measured and compared between the patients’ groups. Kruskal-Wallis test was used for statistical analysis.

Results

Six patients were asymptomatic, fifteen with chronic infarction were stable, and twelve with acute/subacute infarction were symptomatic. The mVFR of ipsilateral middle cerebral artery in symptomatic patients was significantly lower than those in stable or asymptomatic patients (73.7±45.6 mL/min vs. 119.9±36.1 mL/min vs. 121.8±42.0 mL/min; P = 0.04). Total sum of the mVFR of ipsilateral anterior, middle, and posterior cerebral arteries was significantly lower in symptomatic patients than those in other groups (229.3 ± 51.3 mL/min vs. 282.0±68.6 mL/min vs. 314.0±44.4 mL/min; P = 0.02).

Conclusions

Q-MRA could be helpful to demonstrate the difference in the degree of primary collateral flow in ICA occlusion between the patients with recent symptomatic ischemia and those without.

Elongated styloid processes and calcified stylohyoid ligaments in a patient with neck pain: implications for manual therapy practice

OBJECTIVE

The purpose of this paper is to present a case of a patient with neck pain, tinnitus, and headache in the setting of bilateral elongated styloid processes (ESP) and calcified stylohyoid ligaments (CSL), how knowledge of this anatomical variation and symptomatic presentation affected the rehabilitation management plan for this patient, and to discuss the potential relevance of ESPs and CSLs to carotid artery dissection.

CLINICAL FEATURES

A 29-year-old male military helicopter mechanic presented for chiropractic care for chronic pain in the right side of his neck and upper back, tinnitus, and dizziness with a past history of right side parietal headaches and tonsillitis. Conventional radiographs showed C6 and C7 spinous process fractures, degenerative disc disease at C6/7, and an elongated right styloid process with associated calcification of the left stylohyoid ligament. Volumetric computerized tomography demonstrated calcification of the stylohyoid ligaments bilaterally.

INTERVENTION AND OUTCOME

Given the proximity of the calcified stylohyoid apparatus to the carotid arteries, spinal manipulation techniques were modified to minimize rotation of the neck. Rehabilitation also included soft tissue mobilization and stretching, corrective postural exercises, and acupuncture. An otolaryngologist felt that the symptoms were not consistent with Eagle syndrome and the tinnitus was associated with symmetric high frequency hearing loss, likely due to occupational noise exposure. Initially, the patient's symptoms improved but plateaued by the fifth visit.

CONCLUSION

Neck pain in the presence of ESPs and CSLs can be associated with Eagle syndrome, which can include ipsilateral head and neck pain, odynophagia, dysphagia, and cerebrovascular symptoms. This case, initially thought to be Eagle syndrome, highlights proper diagnostic workup for this condition and presents potential contraindications to consider with regard to cervical spine manipulation in such patients. Manual therapy precautions pertaining to cervical spine manipulation may be appropriate in cases involving ESPs and calcified stylohyoid ligaments.

Endovascular treatment of ruptured internal carotid artery pseudoaneurysms after irradiation for nasopharyngeal carcinoma patients

OBJECTIVES. To evaluate the efficacy and complications of endovascular treatment for ruptured internal carotid artery pseudoaneurysms following irradiation of nasopharyngeal carcinoma. DESIGN. Retrospective case series. SETTING. Tertiary neurosurgical referral unit of a Hong Kong public hospital. PATIENTS. Patients with ruptured radiation-induced internal carotid artery pseudoaneurysms that were treated endovascularly from October 1999 to October 2011 at Queen Elizabeth Hospital were reviewed. Hospital records, imaging, and angiographic data were studied. RESULTS. During the study period, 15 such nasopharyngeal carcinoma patients were treated by endovascular means at Queen Elizabeth Hospital. Ten presented with epistaxis, three with otorrhagia (bleeding from the ear), and two with both. Therapeutic occlusion of the affected internal carotid artery was performed in four patients, and stenting of the artery (with or without coil obliteration of the pseudoaneurysm) was performed in 11. Immediate haemostasis was achieved in all cases. One (7%) of the 15 patients endured symptomatic recurrence of the pseudoaneurysm, and in another an asymptomatic residual pseudoaneurysm was noted in the follow-up angiogram. Three patients suffered clinically significant procedure-related complications, including cerebral infarction (n=2) and brain abscess (n=1). In the angiograms obtained after a mean post-treatment interval of 13 (range, 0.7-60) months, the stent patency rate was 67%. All three patients with occluded stents were asymptomatic. CONCLUSIONS. Ruptured internal carotid artery pseudoaneurysms following radiotherapy is a rare but life-threatening condition. Endovascular treatment by occlusion or reconstruction of the internal carotid artery with stents provides immediate haemostasis and obliteration of the pseudoaneurysms, with a low recurrence rate. Long-term follow-up is necessary to look out for delayed post-treatment complications.