Detection of altered extracellular matrix in surface layers of unstable carotid plaque: an optical spectroscopy, birefringence and microarray genetic analysis.

Erosion and rupture of surface layers in atherosclerotic plaque can cause heart attack and stroke; however, changes in luminal surface composition are incompletely defined. Laser-induced fluorescence spectroscopy (LIFS), with limited tissue penetration, was used to investigate the surface of unstable carotid plaque and correlated with microscopy, birefringence and gene expression. Arterial matrix collagens I, III and elastin were assessed in unstable plaques (n = 25) and reference left internal mammary arteries (LIMA, n = 10). LIFS in addition to selective histological staining with picrosirius red, Movat pentachrome and immunostaining revealed decreased elastin and increased collagen I and III (P < 0.05) in carotid plaque when compared with LIMA. Within plaque, collagen I was elevated in the internal carotid region versus the common carotid region. Polarized light microscopy detected layers of aligned collagen and associated mechanical rigidity of the fibrous cap. Microarray analysis of three carotid and three LIMA specimens confirmed up-regulation of collagen I, III and IV, lysyl oxidase and MMP-12. In conclusion, LIFS analysis coupled with microscopy revealed marked regional differences in collagen I, III and elastin in surface layers of carotid plaque; indicative of plaque instability. Birefringence measurements demonstrated mechanical rigidity and weakening of the fibrous cap with complementary changes in ECM gene expression.

Aneurysms of the distal anterior cerebral artery: results in 59 consecutively managed patients.

OBJECTIVE: The aim of this study was to present the clinical and radiological characteristics, surgical management, and outcome in a large series of patients with aneurysms of the distal anterior cerebral artery (DACA) managed in the microsurgical era. METHODS: The records of 1109 patients with anterior circulation aneurysms managed at the authors' institution between 1970 and 1998 were reviewed. RESULTS: Fifty-nine patients (5.3%) were identified with 67 DACA aneurysms. Seventy-three percent of the patients were women. The mean age of all patients was 47 years. Multiple aneurysms were identified in 51% of all patients, most commonly on the middle cerebral artery. Thirty-six patients had ruptured DACA aneurysms and 23 had unruptured aneurysms. In those with ruptured aneurysms, the admission grade was Grade I in 10 patients (27.8%), Grade II in three patients (8.3%), Grade III in 10 patients (27.8%), Grade IV in seven patients (19.4%), and Grade V in six patients (16.7%). Frontal lobe hematomas occurred in 28% of the patients with ruptured aneurysms and carried a poor prognosis. In those with unruptured aneurysms, 11 were incidental and 12 were identified after a subarachnoid hemorrhage from another aneurysm. The mean diameter was 10 mm in ruptured aneurysms and 5.8 mm in unruptured aneurysms. Fifty-eight patients underwent surgery and one patient was treated with endovascular coiling. Six patients, all with ruptured aneurysms, died. Seventy percent of survivors with ruptured aneurysms had a favorable outcome. CONCLUSION: DACA aneurysms possess a number of characteristics that distinguish them from the more common intracranial aneurysms. With modern neurosurgical and endovascular techniques, an acceptable operative morbidity and mortality can be achieved.

Absence of microemboli on transcranial Doppler identifies low-risk patients with asymptomatic carotid stenosis.

BACKGROUND AND PURPOSE: Carotid endarterectomy clearly benefits patients with symptomatic severe stenosis (SCS), but the risk of stroke is so low for asymptomatic patients (ACS) that the number needed to treat is very high. We studied transcranial Doppler (TCD) embolus detection as a method for identifying patients at higher risk who would have a lower number needed to treat. METHODS: Patients with carotid stenosis of > or =60% by Doppler ultrasound who had never been symptomatic (81%) or had been asymptomatic for at least 18 months (19%) were studied with TCD embolus detection for up to 1 hour on 2 occasions a week apart; patients were followed for 2 years. RESULTS: 319 patients were studied, age (standard deviation) 69.68 (9.12) years; 32 (10%) had microemboli at baseline (TCD+). Events were more likely to occur in the first year. Patients with microemboli were much more likely to have microemboli 1 year later (34.4 versus 1.4%; P<0.0001) and were more likely to have a stroke during the first year of follow-up (15.6%, 95% CI, 4.1 to 79; versus 1%, 95% CI, 1.01 to 1.36; P<0.0001). CONCLUSIONS: Our findings indicate that TCD- ACS will not benefit from endarterectomy or stenting unless it can be done with a risk <1%; TCD+ may benefit as much as SCS if their surgical risk is not higher. These findings suggest that ACS should be managed medically with delay of surgery or stenting until the occurrence of symptoms or emboli.

Percutaneous retrogasserian glycerol rhizotomy in the treatment of tic douloureux associated with multiple sclerosis.

OBJECTIVE: Patients with multiple sclerosis (MS) have a relatively high incidence of tic douloureux (TD) and often do not tolerate medical therapy well. The minimally invasive nature of percutaneous retrogasserian glycerol rhizotomy (PRGR) renders it ideal for first-line surgical treatment of TD. We sought to ascertain the benefits of PRGR in patients with MS and to determine whether hypalgesia after PRGR correlates with efficacy. METHODS: We assessed 97 glycerol procedures performed in 53 patients followed prospectively for treatment of TD associated with MS. Factors assessed included degree of pain relief, postoperative hypalgesia, procedural morbidity, medication use, time to pain recurrence, and number and type of subsequent procedures. RESULTS: Complete pain relief was obtained in 78% of patients after the initial glycerol injection, and partial relief was obtained in 13% of patients. Long-term follow-up (mean, 81 mo) demonstrated a recurrence rate of 59%, with a mean time to recurrence of 17 months. Actuarial recurrence rates were 50% at 12 months and 60% at 24 months. Twenty-four patients underwent a second or subsequent PRGR for recurrent pain and achieved similar rates of pain relief and time to recurrence. Facial sensory loss was associated with a higher likelihood of pain relief (P < 0.05), with longer time to pain recurrence (P < 0.05), and with decreased use of medication after surgery (P < 0.01.) CONCLUSION: PRGR is an effective, low-morbidity surgical procedure in the management of TD complicating MS. The presence of facial sensory loss after PRGR is associated with prolonged efficacy.

Dural cavernous angioma: a preoperative diagnostic challenge.

BACKGROUND: Dural cavernous angiomas are uncommon benign vascular malformations which may present intraoperative difficulties in hemostasis when the diagnosis is not suspected preoperatively. Preoperative diagnosis can be difficult when angiomas show atypical features and share imaging characteristics with other entities. METHODS: A patient presented with a radiographically aggressive lesion, subsequently identified as a dural cavernous angioma. The lesion is reviewed and its clinical, radiographic, and pathological features are compared with other vascular malformations. CASE REPORT: A 40-year-old man presented with new onset seizures and an enhancing lesion infiltrating the floor of the right middle cranial fossa. Due to its aggressive radiographic appearance, initial considerations included chondrosarcoma, meningioma or metastasis. Pathological examination, however, revealed the lesion to be a cavernous angioma of dura. CONCLUSION: This uncommon lesion may present a diagnostic challenge with significant intraoperative implications. T2 sequence hyperintensity in a relevant lesion should raise suspicion of an hemangioma. It is important to be aware of this entity and its potential to mimic other entities on radiographic grounds.