Seizures following carotid endarterectomy in patients with severely compromised cerebral circulation

An uncommon case of nonconvulsive status epilepticus successfully treated with enteral Brivaracetam

BACKGROUND AND AIM OF THE WORK

We present a case of a woman affected by nonconvulsive status epilepticus (NCSE) caused by cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy (CEA) who was successfully treated with Brivaracetam (BRV) administered via nasogastric tube (NGT).

CASE PRESENTATION

An 82-years old woman was referred for increasing blood pressure, severe headache and two focal motor seizures on postoperative day four after right CEA. CT scan showed edema of the right hemisphere with a midline shift of 5 mm. The patient underwent daily Electroencephalography (EEG) monitoring which showed continuous epileptiform discharges over the right hemisphere, compatible with a diagnosis of status epilepticus. She was treated with standard antiepileptic drugs (Phenytoin, Lacosamide and Levetiracetam iv) without clinical response. A therapeutic trial with BRV 200mg administered via nasogastric tube (NGT) was tried which resulted in substantial clinical benefit.

CONCLUSIONS

The administration of new antiepileptic drugs (AEDs) such as BRV may result in significant clinical improvement in refractory cases of status epilepticus. The enteral administration of AEDs via NGT should always be considered for refractory cases of status epilepticus when standard iv treatment has failed or is not possible.

Timing of carotid endarterectomy after recent minor to moderate stroke

OBJECTIVE

Early carotid endartectomy is generally favored by vascular surgeons in patients after a minor to moderate stroke. Herein, we compared the results of early versus delayed carotid endartectomy in patients presenting with similar National Institutes of Health Stroke Scale findings after a recent minor to moderate stroke.

METHODS

A retrospective analysis of 101 patients undergoing carotid endartectomy after a recent stroke in the distribution of the branches of the middle cerebral artery with >70% internal carotid artery stenosis from 2000 to February 2018 was performed.

RESULTS

Sixty patients had carotid endartectomy within 2 weeks (group A) and 41 had carotid endartectomy within 2-8 weeks of stroke (group B). Associated factors, such as coronary artery disease, hypertension, diabetes mellitus, hyperlipidemia, nicotine abuse, chronic obstructive pulmonary disease, and renal failure, were similar in both groups. However, there was preponderance of male patients in group B (0.01). In group A, 35 patients presented with minor stroke (National Institutes of Health Stroke Scale 1-4) and 25 had a moderate stroke (National Institutes of Health Stroke Scale 5-15). In group B, 21 had a minor stroke and 20 had a moderate stroke (P = .54). Perioperative stroke occurred in 4 patients in group A and none in group B (P = .14), with perioperative stroke and death rate of 4.0%. Postoperative seizures occurred in 1 patient in group A and three in group B (P = .30).

CONCLUSION

Early as well as delayed carotid endartectomy in patients with minor to moderate stroke results in a satisfactory outcome. To prevent recurrent stroke in the waiting period, early carotid endartectomy should be preferred.

Uncommon Etiology for Seizure: Cerebral Hyperperfusion Syndrome

Cerebral hyperperfusion syndrome (CHS) is a rare life-threatening complication of carotid endarterectomy (CEA) and carotid artery stenting (CAS) for carotid artery stenosis. The incidence varies between 0 and 3%, depending on the severity of the stenosis, perioperative hypertension, and contralateral carotid stenosis. This case report reports a 53-year-old female patient presenting with decreased alertness and multiple tonic-clonic seizures, in the background of bilateral CEA. She was found to have bilateral carotid stenosis. Her left CEA was performed three months prior and right CEA was four days prior to her current presentation with seizures. After bilateral CEA, the imaging showed extensive pathologic process involving primarily the subcortical white matter and overlying cortex, more on the right cerebral hemisphere. On follow-up six weeks later, she reported no recurrent seizures and imaging showed decrease in abnormal signal intensity of the grey and white matter. This was indicative of near complete resolution of hyperperfusion damage. CHS is a rare complication due to the loss of autoregulation of the cerebrovascular system and increased blood flow status after bilateral CEA. This case is reported because of a rare and unique presentation of seizures in the background of bilateral CEA.

[Delayed post-operative epileptic seizure after carotid endarterectomy: a case of cerebral hyperperfusion syndrome?]

The so-called cerebral hyperperfusion syndrome is basically due to a lack of cerebral autoregulation, inability to control the restoring of flow after revascularisation surgery. It present clinically as intense migraine, epileptic seizures, or neurological focality. It may even progress to an intracerebral haemorrhage. It usually appears a few days after surgery. We present the case of a patient subjected to a carotid endarterectomy, who had an epileptic episode in the late post-operative period. We attributed a cerebral hyperperfusion syndrome as the most likely cause. Knowledge of this syndrome may help to correctly orientate and treat the neurological complications that appear after this type of surgery.

Case report: Aggressive blood pressure management for carotid endarterectomy hyperperfusion syndrome

PURPOSE

Cerebral hyperperfusion syndrome (CHS) is a rare but potentially devastating complication following cerebral revascularization. Management of CHS requires aggressive blood pressure control to prevent stroke and intracerebral hemorrhage. This case report documents a severe case of CHS, and outlines a successful outcome associated with aggressive blood pressure control.

CLINICAL FEATURES

A 67-yr-old gentleman, nine days post left carotid endarterectomy, required tracheal intubation and intensive care unit admission following seizures and acute right-sided weakness. A computed tomography scan and magnetic resonance imaging revealed significant vasogenic edema in the left middle cerebral artery territory, without evidence of infarction. The history and radiographic findings suggested CHS. As such, a systolic blood pressure target was set at 90-140 mmHg. This blood pressure parameter was lower than typically targeted following acute ischemic or hemorrhagic stroke. Rapid clinical improvements were seen by day five, and tight blood pressure control was maintained throughout. Repeat computed tomography and magnetic resonance imaging revealed improved edema and no evidence of infarct or hemorrhage.

CONCLUSION

Cerebral hyperperfusion syndrome is believed to occur following restoration of blood flow to a brain with impaired autoregulation due to chronic hypoperfusion. Massive brain edema and hemorrhage can result from higher pressures. Clinicians should be aware of this potential complication following cerebral revascularization procedures, and the importance of establishing blood pressure targets which are considerably lower than for other patients with similar clinical presentations.

Hyperperfusion Syndrome after Carotid Endarterectomy

The hyperperfusion syndrome is a rare delayed postoperative complication of carotid endarterectomy (CEA) characterized by headache and seizure, with or without intracranial edema or hemorrhage. Between January 1996 and December 2003, 1,602 CEAs were performed. Six patients (0.4%) developed symptoms of hyperperfusion within 2 weeks of surgery. All patients had critical stenoses, five > or =90% and one 80-90%, with poor backbleeding from the distal internal carotid artery noted at operation in all cases. Five patients were asymptomatic prior to operation; one had a hemispheric transient ischemic attack. Three patients had severe contralateral internal carotid disease (two occlusions and one severe stenosis). Two patients developed severe, self-limiting headache that prolonged hospitalization. Three patients had ipsilateral intracranial bleeding, two occurring after an uneventful postoperative course. After initial discharge from the hospital, severe intracranial hemorrhage caused death in two patients. One patient experienced focal seizures 1 week after discharge. Hypertension did not appear to be related to the symptoms in any case. During the study period, the hyperperfusion syndrome caused three of five perioperative strokes (60%) and two of seven deaths (29%) in the entire endarterectomy population. Although rare, the hyperperfusion syndrome accounts for a significant percentage of the neurological morbidity and mortality following CEA.

Poststroke Epilepsy

Seizures and status epilepticus can be a presenting feature of acute stroke. They may occur in its early (<7 days) clinical course or be a remote (>7 days) complication. Most seizures are single, either partial or generalised. Early and remote seizures seem to have different predictors and pathogenesis. Seizures are more frequent in severe and disabling strokes, haemorrhagic strokes and those with cortical involvement. The risk of epilepsy is higher for patients with early seizures, cortical infarctions and lobar haemorrhages and in dependent patients. Early or remote seizures do not have a significant influence on dependency or mortality, although seizures and status epilepticus can be a direct cause of death. Treatment can be started after a first or a recurrent seizure. Treatment options include phenytoin, carbamazepine, valproic acid (valproate sodium) and the new antiepileptic drugs (AEDs). New AEDs can be used to decrease the likelihood of drug interactions and adverse effects in patients who do not tolerate the classic AEDs and in treatment failures with classic AEDs. Large observational studies to define prognostic factors for poststroke seizures in specific stroke subtypes are needed. Randomised controlled trials of AED prophylaxis for acute and remote seizures are essential to improve the evidence level of current guidelines and recommendations.

The haemodynamic effect of carotid endarterectomy

OBJECTIVES

to assess the haemodynamic effect of carotid artery surgery, and to relate postoperative changes to the state of cerebral circulation before revascularisation.

MATERIALS AND METHODS

using transcranial Doppler we studied bilateral middle cerebral artery (MCA) flow velocities before and on 1st day, 2nd or 3rd day and 4th or 5th day and 3 months after carotid surgery in 61 patients. In addition, ipsilateral MCA flow velocity was monitored continuously during surgery. Data were related to the internal carotid artery (ICA) perfusion pressure (cerebral perfusion pressure index, CPPI), measured directly before ICA clamping.

RESULTS

postoperatively, MCA flow velocities increased significantly overall (p<0.01), mainly due to pronounced and longer lasting flow velocities in the group of 18 patients with CPPI<0.7 (p<0.05). Flow velocities peaked - absolute as well as relative - on the first postoperative day and then gradually levelled off to reach preoperative values after 4-5 days in patients with high CPPI, whereas MCA flow velocities remained increased in the group of patients with low CPPI. At 3 months flow velocities in both groups were normalised. New neurological symptoms occurred in four patients, who all had low CPPI preoperatively (22% (4/18) vs 0%; Fisher's exact test: p=0.006).

CONCLUSION

some degree of hyperperfusion was seen in most patients, but the changes were significantly more pronounced in patients with preoperative hypoperfusion, who also suffered significantly more neurological complications.

Prevention of postoperative wound haematomas and hyperperfusion following carotid endarterectomy

OBJECTIVE

To study the incidence of wound haematomas and hyperperfusion following carotid endarterectomy and the effect of changes in perioperative management.

METHODS

We undertook a prospective audit of the postoperative outcome of 300 consecutive carotid endarterectomies performed for a symptomatic stenosis of the internal carotid artery, under the care of a single consultant.

RESULTS

audit of the first 100 operations between 1990-93 resulted in 4 changes to clinical practice. These included the use of Dacron instead of vein because of 3 vein patch blowouts, invasive postoperative monitoring of blood pressure, and the use of intravenous beta-blockers to control hypertension, because of 4 hyperperfusion injuries. The use of 10F suction drains was discontinued, because they did not prevent 8 wound haematomas. The results of the second 100 cases between 1994-97 and the third 100 cases between 1998-2000 confirmed no further hyperperfusion injuries or patch blowouts (p =0.01 and 0.04 respectively). Larger 14F suction drains were reintroduced for the third series because of thirteen haematomas in the second series (p =0.09). Only 4 haematomas occurred in the third series ( p =0.05). The need for beta-blockers fell in the third series due to the introduction of local anaesthesia (p =0.0001).

CONCLUSION

The use of Dacron patches and postoperative control of hypertension has reduced the incidence of haemorrhage and hyperperfusion after carotid endarterectomy. Larger suction drains may also help.

Cerebral hyperperfusion syndrome after percutaneous transluminal stenting of the craniocervical arteries

OBJECTIVE

Cerebral hyperperfusion syndrome is a recognized complication of carotid endarterectomy, with a reported incidence of 0.3 to 1.2%. The incidence of cerebral hyperperfusion after endovascular revascularization procedures of the craniocervical arteries remains unknown. We evaluated the incidence of cerebral hyperperfusion syndrome in our endovascular revascularization series. To our knowledge, there are no previous studies evaluating the incidence of hyperperfusion syndrome after percutaneous transluminal angioplasty/stenting.

METHODS

Between March 1996 and February 2000, 140 patients underwent percutaneous transluminal angioplasty/stenting of the craniocervical arteries at our institution. In all patients, selective bilateral arteriography of the carotid and vertebral arteries was performed to document the sites of craniocervical stenosis and collateral blood flow and the results of the endovascular revascularization procedure. We then reviewed all pertinent medical records, arteriographic films, and sectional imaging studies to determine the incidence of cerebral hyperperfusion in this series.

RESULTS

Seven patients (5.0%) developed clinical or radiological manifestations of cerebral hyperperfusion. In the target group, percutaneous transluminal stenting achieved a 90 to 100% reduction in stenotic lesions (mean stenosis, 91%) of the carotid (n = 5) and vertebral (n = 2) arteries. All seven patients remained neurologically stable immediately after treatment. There was delayed development of clinical and radiographic findings, suggestive of cerebral hyperperfusion. Six patients showed evidence of ipsilateral hemispheric edema, including two patients who developed intracranial hemorrhage (one parenchymal, one parenchymal and subarachnoid) documented by computed tomographic brain scans. Symptoms resolved within 72 hours in the four patients without hemorrhage. The two patients with hemorrhage recovered during a more protracted period (range, 3 wk to 6 mo). There were no long-term sequelae or deaths during a cumulative follow-up of 84 months (mean follow-up, 12 mo).

CONCLUSION

Hyperperfusion syndrome is an uncommon but potentially serious complication of extracranial and intracranial angioplasty and stenting procedures. The clinical manifestations are similar to hyperperfusion syndrome after carotid endarterectomy; however, the prevalence may be greater in the high-risk cohort commonly referred for endovascular treatment. Our findings suggest that patients undergoing endovascular stenting procedures should be closely monitored for evidence of hyperperfusion, with careful monitoring of blood pressure, heart rate, and anticoagulation. Further research is needed to confirm that cerebral hyperperfusion is the pathogenesis of this condition.

Forebrain ischemia: effect on pharmacologically induced seizure thresholds in the rat

Seizures are common after severe cerebral ischemia. To examine the mechanisms underlying these seizures, we determined the impact of prior forebrain ischemia on the seizure thresholds of four convulsants with differing modes of action: lidocaine, pentylenetetrazol (PTZ), N-methyl-D-aspartate (NMDA), and picrotoxin. Anesthetized Sprague-Dawley rats were chronically instrumented with screw electrodes and vascular catheters, and then subjected to 10 min of forebrain ischemia, produced by carotid occlusion and hypotension (mean arterial pressure to 30 mmHg). Animals were then awakened. 6, 24 or 48 h later, groups of awake animals received intravenous infusions of the four drugs. The total dose of drug infused prior to either electrical seizures (lidocaine, PTZ, and picrotoxin) or tonic-clonic convulsions (all drugs) were noted. For each drug, a group of Sham animals (no ischemia) served as controls. There were markedly different patterns of changes in the convulsant thresholds for the drugs. For example, at 6 h post-ischemia, rats treated with lidocaine died before convulsing, while the threshold for PTZ increased by 86%. There was no change in the picrotoxin threshold at 6 h, but the dose of NMDA needed to induce tonic-clonic seizure activity was reduced by 70%. By 48 h, lidocaine and PTZ thresholds had returned to values similar to those in Shams, but the NMDA threshold had now increased to a value 62% greater than Sham. Ten minutes of cerebral ischemia is followed by a complex and changing pattern of susceptibility to chemical convulsants. Finding suggests that early post-ischemic seizures may be related to increased NMDA receptor sensitivity.

Long-term hemodynamic effects of carotid endarterectomy

BACKGROUND AND PURPOSE

The presence and importance of hemodynamic factors to the beneficial effect of carotid endarterectomy (CEA) in patients with severe stenosis of the internal carotid artery (ICA) is unclear. The purpose of this study was to investigate possible hemodynamic changes caused by a severe ICA stenosis and the subsequent changes after CEA.

METHODS

Hemodynamic parameters were acquired with dynamic susceptibility contrast MRI. Regional cerebral blood volume (rCBV), mean transit time (MTT), time of appearance, and time to peak were determined in 19 patients with severe stenosis (>70%) of the ICA before and after CEA and in 33 control subjects. Four patients had an occlusion of the contralateral ICA. Corresponding T2-weighted MRI and inversion recovery MRI scans were used for segmentation of gray and white matter regions.

RESULTS

In the hemisphere ipsilateral to the stenosed ICA, no significant differences were found for the rCBV or MTT between patients and control subjects. Also, no significant alterations in these two parameters were observed after CEA. In the hemisphere contralateral to the stenosed ICA, hemodynamic changes were observed only in patients with an ICA occlusion contralateral to the stenosed ICA. In these patients, rCBV, MTT, time of appearance, and time to peak were all increased in the contralateral hemisphere. After CEA, all hemodynamic parameters fell in the normal range.

CONCLUSIONS

Although CEA does improve the cerebral circulation in patients with a severe stenosis and a contralateral ICA occlusion, the hemodynamic effects of CEA in patients with severe stenosis without a contralateral ICA occlusion are negligible.