Abstract

OBJECTIVE

To assess the impact of surgical treatment of unruptured and ruptured middle cerebral artery (MCA) aneurysms on cognitive functioning and health-related quality of life (HRQOL).

METHODS

This was a prospective study enrolling 15 patients with unruptured MCA aneurysms and 22 patients with ruptured MCA aneurysms in good clinical condition postictally. Patients with unruptured aneurysms underwent preoperative neuropsychological testing and answered 2 HRQOL questionnaires. All patients were investigated 3 and 12 months postoperatively with a comprehensive neuropsychological test battery, clinical investigation, and interview. The modified Rankin Scale score, Glasgow Outcome Scale score, employment status, and 2 HRQOL questionnaires were also used for assessment.

RESULTS

Preoperative cognitive deficits were aggravated 3 months after surgery for the unruptured MCA aneurysm group, but after 12 months these patients performed at their preoperative level. Subjects who underwent clipping for ruptured MCA aneurysms had reduced verbal memory; otherwise, they had close to normal cognitive function 12 months postoperatively. There was no difference between the 2 groups in Rankin Scale score or Glasgow Outcome Scale score. High preoperative levels of anxiety and depression markedly decreased after repair of an unruptured aneurysm; however, in both groups, HRQOL was reduced on the same measures even 12 months after surgery. Patients treated for unruptured MCA aneurysms regained their preoperative employment status, whereas only 60% of those who had bled from their aneurysm had returned to full-time work after 12 months.

CONCLUSION

Surgical treatment of unruptured MCA aneurysms does not cause new cognitive deficits, but it reduces some aspects of HRQOL in a similar manner as in patients who undergo clipping for ruptured MCA aneurysms.

Up to 50% of patients who experience the rupture of an intracranial aneurysm die or develop long-term disabilities (22). Therefore, an increasing number of patients have an unruptured intracranial aneurysm (UIA) treated prophylactically. In general, the annual risk of aneurysm rupture is estimated to be 1 to 2%, whereas the morbidity of UIA treatment is reported to be 5 to 25%, with mortality ranging from 0 to 7% (22). However, for each patient and specific aneurysm, the risk of rupture has to be weighed against the risk associated with treatment. The International Study of Unruptured Intracranial Aneurysms suggested that diminished cognitive status can be attributed significantly to the high morbidity after treatment of UIAs (20). However, there has been limited focus on the neuropsychological and psychosocial outcomes of UIA treatment, as most studies (6,11,20,23) have used outcome measures such as the Rankin Scale score (18), the Glasgow Outcome Scale (GOS) (10), or the Mini-Mental State Examination (5), which are not capable of a proper neuropsychological delineation of cognitive functioning. Patients might therefore have been classified as having a “good outcome” without having returned to their preoperative level of functioning (22).

In addition, in some studies, the level of preoperative cognitive and psychosocial performance is not known (19,22). Hillis et al. (7) included pre- and postoperative testing and found deficits in verbal fluency, immediate and delayed verbal recall, as well as decreased executive functioning 3 months after UIA treatment. These cognitive impairments are, in fact, similar to those seen after subarachnoid hemorrhage (SAH) from a ruptured cerebral aneurysm. Most studies of cognitive function after SAH (9,15,21) have mainly attributed cognitive impairments to the cerebral damage caused by the bleed rather than the effect of treatment per se on the brain.

To provide adequate counseling on whether to treat a UIA, the incidence and range of cognitive deficits consequent to UIA repair have to be determined. Another important factor in the decision making regarding treatment of a UIA is the effect of the treatment on the patient's health-related quality of life (HRQOL) and especially on the often high levels of anxiety reported by patients harboring an untreated UIA. Raaymakers (17) found that elective surgery on UIAs had a brief negative impact on HRQOL shortly after surgery, but after 1 year, HRQOL was improved, although not quite to the preoperative level. To determine the effect of treatment of a middle cerebral artery (MCA) UIA on cognitive functioning and HRQOL, we designed a prospective study in which all patients undergoing prophylactic surgical repair of unruptured MCA aneurysms were tested preoperatively as well as 3 and 12 months postoperatively using a comprehensive neuropsychological test battery, a clinical interview, and 2 HRQOL questionnaires (General Health Questionnaire-30 and SF-36). The modified Rankin Scale, GOS, and employment status were also included in the test battery. To delineate the effects of SAH on neuropsychological performance, we included a group of patients who underwent surgical repair of a ruptured MCA aneurysm.

PATIENTS AND METHODS

Patients

The present study had a prospective design and enrolled all patients with no history of SAH admitted to the Department of Neurosurgery at Rikshospitalet University Medical Center in Oslo, Norway, for prophylactic treatment of an MCA UIA between March 1, 2005, and November 30, 2006. For comparison, surgically treated patients in preoperative Hunt and Hess Grades I to III (8) from a ruptured MCA aneurysm between January 1, 2003, and February 27, 2005, were included. Exclusion criteria for both patient groups were: 1) history of earlier cerebrovascular, psychiatric, or neurological disease; 2) age older than 70 years; 3) lack of fluency in Norwegian; 4) abuse of narcotic drugs or alcohol; and 5) aphasia. The present study is part of a larger project on cognitive functioning and HRQOL after aneurysmal SAH and was approved by the Regional Ethics Committee. Written and oral informed consent was obtained from all individuals included in the study.

Methods

All individuals underwent a physical examination upon arrival at our hospital, before discharge, and at the 3- and 12-month follow-up examinations, at which they were scored according to the modified Rankin Scale (18) and GOS (10) scores. Their employment status was also assessed. The immediate preoperative clinical state of the patients with ruptured MCA aneurysms was expressed according to the Hunt and Hess score (8). Social and medical history, fluency in Norwegian, and clinical features at onset were obtained by interview of patient/family and review of medical records for both groups. All patients underwent cerebral computed tomography with computed tomographic angiography before treatment, just before discharge, and at later follow-up. The site and size of the aneurysm, pattern of bleed (Fisher score [4]), Evans index (maximum bifrontal ventricle size at the level of the foramen of Monro divided by the inner cranial diameter at this level [13]), and ventricular score (13) were registered.

Surgical Aneurysm Repair

The surgical aneurysm repair was similar for the 2 groups. All patients were treated by the same surgeons (WS), who carried out the aneurysm repair in their standardized manner. During surgery, minimal brain retraction was obtained by optimal positioning of the patient on the operating table (Newton's retractor), liberal cerebrospinal fluid removal, and the use of dissection techniques minimizing the need for brain spatulas. Moderate hypothermia (33–36°C) was applied, and cefalotine, corticosteroids, and mannitol were administered. We routinely used temporary parent vessel occlusion (<5 minutes) under thiopental protection (500–1000 mg thiopental, administered intravenously 90 seconds before vessel occlusion) during critical phases of aneurysm dissection and clipping. Large aneurysms were collapsed before clipping by “suction-decompression” technique. Thrombotic masses preventing aneurysm closure were removed by intra-aneurysmal thrombectomy. Adequate clip closure was checked through visual inspection or opening of the aneurysm, and adequate flow was verified in adjacent vessels by use of micro-Doppler (14). Low-molecular-weight heparin (dalteparin [Fragmin; Pfizer, Inc., New York, NY]; 2500 IU/d) was administered from the day after surgery until the patient was fully mobilized.

Neuropsychological Examination

The patients with unruptured aneurysms underwent the preoperative neuropsychological examination on the day before surgery. Both patient groups had neuropsychological examinations at 3 and 12 months. Table 1 provides a description of the cognitive functions evaluated by the various neuropsychological tests. Owing to time constraints and patient functioning, the group with ruptured MCA aneurysms went through a shorter neuropsychological test battery at 3 months. All patients also answered the General Health Questionnaire-30 and SF-36 at 3 and 12 months for evaluation of HRQOL.

TABLE 1.

Description of cognitive functions as measured by neuropsychological testsa

Statistical Analysis

The data were not normally distributed; therefore, nonparametric tests were used. Findings were considered significant at a P value of less than 0.05. Statistical analysis was conducted according to SPSS procedures (Version 13.0 for Windows; SPSS, Inc., Chicago, IL). For the neuropsychological test results, both raw scores and standardized z-scores with mean (= 0) and standard deviation (= ±1) are shown.

RESULTS

Clinical and Radiological Characteristics

The preoperative characteristics of the 2 patient groups, including sex, age, education, smoking habits, comorbidity, aneurysm site and size, Evans index, and ventricular score, are presented in Table 2. Except for the preoperative ventricular score, there were no significant differences between the groups. The immediate preoperative clinical state of the 22 patients with ruptured MCA aneurysms was as follows: 6 patients were in Hunt and Hess Grade I, 11 were in Grade II, and 5 were in Grade III. The amount and distribution of blood on computed tomographic scans according to Fisher (4) were as follows: 8 patients had a thin layer of subarachnoid blood (Fisher score, 2), 4 patients had a thick layer of subarachnoid blood (Fisher score, 3), and 10 patients had intracerebral hemorrhage (Fisher score, 4). Intraoperative characteristics, such as the use of temporary parent vessel occlusion and time on mechanical ventilatory support, are presented in Table 2. There were no differences between the 2 groups, except that the patients who underwent clipping for ruptured MCA aneurysms required a longer time on mechanical ventilatory support.

TABLE 2.

Pre- and postoperative patient characteristics, intraoperative and radiological characteristics, and clinical outcome of patients with unruptured and ruptured middle cerebral artery aneurysmsa

The postoperative clinical and radiological scores as well as clinical outcomes in terms of modified Rankin Scale and GOS are listed in Table 2. The sole significant difference between the groups was a higher number of low-attenuating lesions on the discharge cerebral computed tomography in those who underwent clipping for ruptured MCA aneurysms; most of these lesions, however, resolved within the follow-up period and did not represent manifest cerebral infarction. None of our patients died, and none developed chronic hydrocephalus.

Neuropsychological Findings

Patients with Unruptured MCA Aneurysms

The neuropsychological performance in the patients with unruptured aneurysms is reported in Table 3. This group scored weaker preoperatively than expected from the general population mean in several tests: visual memory (Rey Complex Figure), motor speed (Grooved Pegboard), language (Vocabulary test on the Wechsler Abbreviated Scale of Intelligence-Revised [WASI-R]), and executive functions (the switching tasks on the Verbal Fluency and Design Fluency Tests). All other tests were within the expected norm preoperatively. Three months postoperatively, we found a further decline in some of the functions performed poorly preoperatively: visual memory (Rey Complex Figure), motor speed (Grooved Pegboard), and language (Vocabulary, WASI-R). In addition, verbal memory (California Verbal Learning Test-II [CVLT-II]) and psychomotor speed (Trail Making Test visual scanning) was more than −0.5 standard deviation below the expected mean. Between 3 to 12 months after surgery, a cognitive improvement to basically preoperative scores occurred. From preoperative levels through 12 months, there was a trend toward declining psychomotor speed regarding the processing of high-frequency repeating stimuli (Color-Word Interference Tests), whereas some of the executive functions had improved over time (Verbal Fluency Test and Design Fluency Test). Compared with the expected population mean, the performance of the patients at 12 months postoperatively was poorer only in motor speed (Grooved Pegboard) and language (Vocabulary WASI-R). Thus, the cognitive functioning in the patients with unruptured MCA aneurysms was closer to the expected population mean 12 months after surgery than it was preoperatively.

TABLE 3

Mean raw scores for each of the primary neuropsychological measurementsa

Patients with Ruptured MCA Aneurysms

The neuropsychological test results at 3 and 12 months in the patients with ruptured MCA aneurysms are presented in Table 3. At 3 months, the patients scored significantly below the expected population mean on verbal memory (CVLT-II Long-term Memory), visual memory (Rey Complex Figure), motor speed (Grooved Pegboard), and psychomotor speed (Digit Symbol, Wechsler Adult Intelligence Scale III). Between 3 and 12 months after surgery, these patients showed a normalization in motor speed (Grooved Pegboard), psychomotor speed (Digit Symbol), and executive functions (Color Word Interference Test Inhibition). This resulted in a cognitive function corresponding to that of the normal population, with the only exception being reduced verbal memory (CVLT-II Total Learning and CVLT-II Short-term Memory), which was more than 0.5 standard deviation below the expected population mean at 12 months and actually declined between 3 and 12 months. These patients also had reduced language (Vocabulary, WASI-R) at 12 months.

HRQOL

Patients with Unruptured MCA Aneurysms

On the preoperatively administered HRQOL test, the patients with unruptured MCA aneurysms had significantly higher anxiety and depression scores than the norm (P < 0.01 and P < 0.02, respectively) (Fig. 1). They also reported decreased well-being and impaired social functioning (P < 0.01 and P < 0.03, respectively). On the SF-36 questionnaire (Fig. 2), the role physical (P = 0.02), general health (P < 0.01), social functioning (P = 0.05), and mental health (P < 0.01) scores were significantly decreased compared with the norm. At 3 months postoperatively, anxiety and depression had subsided, mental health had improved (P < 0.03), whereas the patients reported a significant worsening of coping, social functioning, and role physical (Figs. 1 and 2). The other parameters were not significantly affected by surgery. At 12 months postoperatively, well-being (P = 0.01), role physical (P < 0.01), and general health (P < 0.01) were below the norm. Bodily pain had worsened from 3 months postoperatively and was significantly lower than the norm at 12 months (P < 0.01).

FIGURE 1.

Health-related quality of life (HRQOL) results of the General Health Questionnaire-30 (GHQ-30) for both groups, compared with the population norm. High score indicates poor functioning. MCA, middle cerebral artery.

FIGURE 1.

Health-related quality of life (HRQOL) results of the General Health Questionnaire-30 (GHQ-30) for both groups, compared with the population norm. High score indicates poor functioning. MCA, middle cerebral artery.

FIGURE 2.

HRQOL results of the SF-36 questionnaire for both groups, compared with the population norm. Low score indicates poor functioning.

FIGURE 2.

HRQOL results of the SF-36 questionnaire for both groups, compared with the population norm. Low score indicates poor functioning.

Patients with Ruptured MCA Aneurysms

Three months after surgery, the patients with ruptured MCA aneurysms reported diminished well-being (P < 0.01), social functioning (P < 0.01), physical functioning (P = 0.04), role physical (P < 0.01), and general health (P < 0.01) as compared with the norm (Figs. 1 and 2). At 12 months, social functioning and role physical had improved but were still lower than the norm (P = 0.03 [Fig. 1] and P < 0.01 [Fig. 2]). General health remained reduced at the same level (P < 0.01), whereas bodily pain had increased (P = 0.02).

Employment Status

Table 4 presents the employment status of the 2 patient groups. The patients with unruptured MCA aneurysms managed to regain their preoperative employment status at 12 months postoperatively. In particular, all patients who were employed full-time preoperatively could return to full-time work. One patient in this group increased from part-time employment to full-time. In contrast, only 60% of the patients with ruptured MCA aneurysms who were working full-time before the ictus had returned to full-time employment 12 months postoperatively. Four patients in that group had returned to part-time employment, and another 4 patients had dropped out of the work force.

TABLE 4

Pre-and postoperative employment status in patients with unruptured and ruptured middle cerebral artery aneurysmsa

DISCUSSION

In the present study, patients who underwent surgical clipping of an unruptured MCA aneurysm had cognitive performance at their preoperative level after 12 months. Patients who underwent clipping after rupture of an MCA aneurysm in Hunt and Hess Grades I through III had cognitive functioning corresponding to that of the normal population in most functional domains after 12 months, but they were afflicted by a significantly reduced verbal memory compared with the population norm. Both groups reported reduced HRQOL compared with population norms. Although patients in the unruptured aneurysm group could return to work, only 60% of patients with ruptured aneurysms had returned to full-time employment 1 year after the SAH.

The subjects treated for unruptured MCA aneurysms had mild preoperative cognitive deficits, including reduced visual memory, motor speed, verbal information processing, and some executive functions. Whether this was related to having a complaint finally leading to the detection of a cerebral aneurysm is unclear, but the possibility cannot be excluded. High levels of preoperative anxiety and depression might also have negative impact on test scores. Three months after the surgery, 3 of 4 cognitive functions that had been impaired preoperatively had worsened, indicating that these functions are especially susceptible, in keeping with earlier findings by Ohue et al. (16) and Hillis et al. (7), whereas Tuffiash et al. (23) did not find any cognitive dysfunction 3 to 6 months after surgery for unruptured aneurysms in good-outcome (GOS 5) patients. Preoperatively normal cognitive domains were not significantly affected by the surgical procedure, except for a minor decrease in verbal memory and some measures of psychomotor functioning at 3 months. However, we found an improvement back to the preoperative level at 12 months in all areas of cognitive functioning. The present study thus indicates that surgical clipping for unruptured MCA aneurysms does not result in permanent cognitive impairments.

In patients with ruptured aneurysms, no data exist about their premorbid cognitive function. Three months after the bleed and surgical repair of the aneurysm, they had reduced verbal and visual memory, as well as reduced motor and psychomotor speed. After 12 months, their cognitive function was equivalent to that of the population mean in most domains except for deficits in verbal memory and language, both functions connected to the left temporal lobe. In this group, there was a prevalence of left-sided aneurysms, which may explain this finding. The reduced verbal memory and language function could theoretically be caused by both the impact from the bleed and the surgical procedure, but the finding that verbal memory deficits were sustained after 12 months only in patients with ruptured aneurysms corroborates most studies of cognitive function after SAH (9,15,21), which have mainly attributed cognitive impairments to the cerebral damage caused by the bleed rather than the effect of treatment per se. There were no other cognitive sequelae in the patients with ruptured aneurysms.

HRQOL was reduced for similar aspects in both patient groups, possibly reflecting the psychological consequence of experiencing a life-threatening disease. The threat of disease becomes most obvious on the preoperative very high scores for anxiety and depression in those with unruptured MCA aneurysms and the normalization of these scores 3 months after clipping. One could argue that the proximity of the testing to the operation (1 day before surgery) increased the anxiety and depression levels. On the other hand, those with aneurysms smaller than 7 mm had elected surgery because of their extreme fear of experiencing hemorrhage, and they may have been more relaxed when they finally got the chance to have the aneurysm secured. In addition, the patients with unruptured aneurysms scored preoperatively lower than the norm on well-being, coping, and social functioning, thereby showing a profile that concurs with the preoperative findings of Brilstra et al. (1). Although anxiety and depression had resolved at 3 months postoperatively, we observed a worsening in other areas. The HRQOL profiles at 3 and 12 months were strikingly similar in those with unruptured and ruptured MCA aneurysms. Similar reduced physical social parameters after unruptured aneurysm surgery have previously been reported by Brilstra et al. (1) and Solheim et al. (19), in contrast to the findings of Raaymakers (17), who concluded that prophylactic surgery on unruptured aneurysms has only a short-term negative impact on HRQOL in most patients. Interestingly, Brilstra et al. (1) found impaired HRQOL and functional health 1 year after surgical treatment but unaffected HRQOL after endovascular treatment. Their findings, together with the similar profile in reduced HRQOL in our 2 patient groups, favor surgical treatment and not hemorrhage as the cause of reduced HRQOL. The fact of having undergone a surgical procedure may also explain the finding of increasing bodily pain after 1 year in both of our groups. This is in consensus with the findings of Brilstra et al. (1) of increased bodily pain in the surgically treated patients but not in the endovascularly treated patients.

Even though patients with a ruptured MCA aneurysm reported similar HRQOL, the psychosocial impact of having had an SAH was much greater, in that only 60% of these patients had managed to return to full-time employment after 1 year. In part, this may be related to their problems with verbal memory. It also seems reasonable to expect a longer interval of recovery in that group of patients.

Our data also show that patients with some cognitive dysfunctions and a subjective decrease in HRQOL were scored as having an excellent outcome on scales such as Rankin or GOS. A favorable outcome score is no guarantee for the patient being in his/her premorbid condition. When asked about the need for psychological intervention before surgery, a majority of our patients with unruptured MCA aneurysms confirmed that they would have benefited from psychological intervention while waiting for the surgery to help alleviate the anxiety surrounding the possible rupture of the aneurysm. Providing patients and their families with simple information is therefore essential to alleviate many fears and misconceptions and allow them to make the necessary adjustment in their lives.

Re-test effects are important sources of error and bias in consecutive neuropsychological testing. To minimize re-test bias, we used alternative test versions when available. For most tests, however, no alternative tests were at hand, and possible re-test effects cannot be fully excluded. This effect, however, could be expected to have the same power in both groups of patients. The small sample size may also affect the results; however, we gave priority to investigating 2 homogeneous groups undergoing the same standardized treatment rather than investigating larger, inhomogeneous groups. Furthermore, studying the outcome of surgical treatment of solely MCA aneurysms can presumably give different results compared with aneurysms in other locations. The outcome of surgical repair of anterior communicating artery aneurysms, for example, could have disclosed more frontal deficits. Finally, we only included patients in clinical good grade after their SAH. In patients with more serious hemorrhages, one could anticipate a less favorable outcome.

CONCLUSIONS

Surgical clipping of an unruptured MCA aneurysm did not cause new cognitive dysfunction. Patients with ruptured MCA aneurysms who were in a postictal good clinical grade had reduced verbal memory 12 months after surgical aneurysm repair but normal functioning in other domains. Although high preoperative levels of anxiety and depression were resolved by surgery, both the patients with unruptured and ruptured aneurysms reported decreased HRQOL on the same measures even 1 year after surgery. Despite a reduced HRQOL, patients treated for unruptured MCA aneurysms regained their preoperative employment status, whereas only 60% of those that had bled from their MCA aneurysm could return to full-time work after 12 months, indicating severe psychosocial impact of the bleed in spite of only mild cognitive dysfunction.

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COMMENTS

Although the number of patients in this study was rather low, this nice article shows that clipping of unruptured aneurysms can nevertheless be safe in experienced hands. Also of importance is the finding that the high preoperative levels of anxiety and depression markedly decreased after clipping, indicating that patients with unruptured aneurysms are usually worried about them; hence, permanent therapy is a huge relief to the patients, in comparison with follow-up only or partial treatment followed by annual or biannual re-visits to the department and possible repeat therapy. Detailed neuropsychological testing should probably be arranged routinely in all patients with ruptured aneurysms before their brief visits to the neurosurgeon at 3 and 12 months, unless patients are already known to be undergoing a multidisciplinary rehabilitation with regular testing included.

Mika Niemelä

Juha A. Hernesniemi

Helsinki, Finland

To investigate the impact of clipping unruptured intracranial aneurysms on cognitive function and quality of life, Haug et al. performed the present prospective study, which included 15 patients with unruptured aneurysms and a matched control group of 22 patients with ruptured middle cerebral artery (MCA) aneurysms. A comprehensive neuropsychological test battery was used preoperatively and 3 and 12 months postoperatively in the unruptured aneurysm group and only postoperatively in the ruptured aneurysm group. The main finding was that temporary neuropsychological deficits but no lasting effects could be recorded after clipping of the unruptured MCA aneurysms.

The study works in a current and highly interesting field. Only a few data exist about the neuropsychological outcome in aneurysm patients, particularly after clipping of unruptured aneurysms. To get a detailed view of the neuropsychological status, a broad test battery is mandatory, which is very extensive and might be a reason for the small study group. However, those 15 patients and the matched control group were extensively characterized and present some interesting aspects regarding the unruptured group alone or in comparison with the ruptured aneurysm group. These data particularly provide more evidence for the benefits of early treatment of unruptured aneurysms and emphasize the potential low morbidity that can be expected after surgical treatment of these aneurysms.

The limitations of the present study (re-test effect and small sample size) are mentioned in the article; they could not be avoided completely. Therefore, it will be of great interest to see whether these data can be confirmed in a larger study or in a comparative independent second study sample.

Dietmar Krex

Gabriele Schackert

Dresden, Germany

This study examines the impact of MCA aneurysm clipping on cognitive function and quality of life. Extensive testing with the General Health Questionnaire-30 and SF-36 in 15 patients with unruptured aneurysms identified transient decreases in verbal memory, which resolved by 1 year, and decreases in quality of life, which persisted at 1 year. Anxiety and depression were markedly improved after surgery, and patients returned to preoperative employment status.

The data in this article demonstrate some important points. First, neuropsychological and psychosocial deficits are missed in patients who would otherwise be recorded as having good outcomes with the Glasgow Outcome Scale or the modified Rankin Scale. Similar observations have been made with other therapies, including carotid endarterectomy and resection of arteriovenous malformations. The authors conclude that cognitive functioning and quality of life should be a part of our outcome analysis for aneurysm patients. Second, neuropsychological and psychosocial deficits cannot be attributed completely to aneurysm rupture, as they are in many other studies. The deficits measured in 22 patients with ruptured MCA aneurysms in this study were more significant than in those patients with unruptured MCA aneurysms, including reduced verbal memory, decreased quality of life, and diminished employment status at 1 year. However, decreased quality of life in patients after treatment of unruptured aneurysms suggests detectable effects from surgery that need to be understood better. For example, are there ill effects from craniotomy, brain retraction, small perforator occlusions during clipping, brain resection, venous compromise, or postoperative bleeding, either individually or cumulatively? Microdissection was not completely responsible for neuropsychological deficits in these patients. This study also documented deficits present before surgery, suggesting that awareness of an aneurysm impairs some cognitive functioning by making the patient scared and depressed.

Michael T. Lawton

San Francisco, California

The authors analyzed 15 patients with unruptured intracranial MCA aneurysms who underwent neurosurgical obliteration and compared these with patients who had ruptured MCA aneurysms; the study attempted to match the patients statistically. The patients with ruptured aneurysms were mostly Grade I (6 patients) and Grade II (11 patients), with 5 patients being Hunt and Hess Grade III. The authors used a neuropsychological test battery as well as clinical investigation and interview to assess the Rankin and Glasgow Outcome Scale scores and 2 different quality-of-life questionnaires (SF-36 and General Health Questionnaire-30). The authors found that, after surgery for an unruptured intracranial aneurysm, there was a transitory decrease in verbal memory at 3 months, but this had subsided at 12 months after surgery. There were high preoperative levels of anxiety, which were markedly decreased after clipping of the aneurysm, and the patients reported coping better. It is of interest that patients with unruptured intracranial aneurysms had similar postoperative reductions in cognitive functioning and quality of life up to the measured 12-month interval, compared with patients with ruptured MCA lesions. Patients treated for unruptured aneurysms had a better capability to regain function postoperatively. There was no difference in Rankin score or Glasgow Outcome score between those treated for ruptured and unruptured aneurysms.

The authors note some of the major confounding variables of the study, including the retest effects as a possible error in any consecutive neuropsychological testing study. They tried to minimize this, as they describe. The reported findings of anxiety are most likely heavily influenced by the fact that the preoperative testing was done shortly before surgery, which is the interval in which anxiety is highest in patients with unruptured aneurysms.

The return to work data are quite interesting. The authors found that, for unruptured aneurysms, at 3 months, 5 of the patients tested were still on sick leave. By 12 months, most of the patients had returned to their preoperative level of activity, including what appears to be 1 patient who returned to full-time work who was not working full-time preoperatively. In the ruptured population, the findings at 12 months showed a significant reduction in those working full-time. There may be a better return to work in patients with ruptured aneurysms at a longer interval of follow-up.

Studies of the type reported by the authors are difficult to perform, owing to the arduous and time-consuming nature of the testing involved. However, this type of study is extremely important, as it has a direct impact on counseling patients with both ruptured and unruptured lesions. As noted by the authors, the number of patients in this study is quite small; however, their observations are in keeping with what is seen clinically in the office in follow-up of these patients with unruptured and ruptured aneurysms. Patients who have not returned to a normal level of functioning shortly after unruptured aneurysm surgery are often reassured with time. Any cognitive issues they have may, in fact, improve to the point where they will regain most of their normal function. For some patients, this may take as long as 18 months. We have observed some patients with a predisposition to depression or other psychiatric problems before treatment who struggled more in the postoperative interval, and these patients may benefit from psychological counseling or transient treatment with antidepressants.

Christopher S. Ogilvy

Boston, Massachusetts

Charles Bell, 1774–1842, The anatomy of the brain, explained in a series of engravings. London: C. Whittingham, Dean-Street, Fetter-Lane, 1802. Courtesy, Rare Book Room, Norris Medical Library, University of Southern California, Los Angeles, California.

Charles Bell, 1774–1842, The anatomy of the brain, explained in a series of engravings. London: C. Whittingham, Dean-Street, Fetter-Lane, 1802. Courtesy, Rare Book Room, Norris Medical Library, University of Southern California, Los Angeles, California.

ABBREVIATIONS:

    ABBREVIATIONS:
  • CVLT

    California Verbal Learning Test

  • GOS

    Glasgow Outcome Scale

  • HRQOL

    health-related quality of life

  • MCA

    middle cerebral artery

  • SAH

    subarachnoid hemorrhage

  • UIA

    unruptured intracranial aneurysm

  • WASI-R

    Wechsler Abbreviated Scale of Intelligence-Revised