Stroke Complications: Hiding in Plain Sight?

March 1, 2007
Norra Macready

Despite the enormous progress made in stroke diagnosis and treatment in recent years, patients continue to experience stroke-related deficits that clinicians-even those working on stroke rehabilitation units-do not always recognize or record. In a recent study of 53 patients who underwent screening tests within 10 days of admission to a stroke unit, every impaired patient had at least 1 undocumented cognitive or sensory deficit. The authors suggested that without formal testing with standardized assessments, much stroke-related impairment goes unrecognized and perhaps untreated.

Despite the enormous progress made in stroke diagnosis and treatment in recent years, patients continue to experience stroke-related deficits that clinicians-even those working on stroke rehabilitation units-do not always recognize or record. In a recent study of 53 patients who underwent screening tests within 10 days of admission to a stroke unit, every impaired patient had at least 1 undocumented cognitive or sensory deficit. The authors suggested that without formal testing with standardized assessments, much stroke-related impairment goes unrecognized and perhaps untreated.1

This may be especially true when patients develop complications that caregivers do not realize may be related to stroke. "Often these are subtle in their presentation. Some conditions, such as pneumonia or bladder infection, may present in unusual ways, so they are missed because everyone is focusing on the neurologic deficits," said Elliott Roth, MD, senior vice president and medical director of the Rehabilitation Institute of Chicago. He recommends that all clinicians maintain a high index of suspicion for subtle changes in a patient's status, which could point toward a possible complication or perhaps even a second stroke.

Indeed, there's good reason for suspicion, because stroke complications are surprisingly common, with an estimated incidence ranging from 40% to as high as 96%, and they are associated with worse outcomes than those of patients who do not experience complications. Fortunately, many of these complications are treatable or even preventable.2

Stroke complications frequently go unrecognized for a variety of reasons. Many doctors-even neurologists-adopt a fatalistic approach because they don't realize just how much more is possible today than when they first trained years ago, said Mark Bayley, MD, medical director of the Neurorehabilitation Program at the Toronto Rehabilitation Institute. "There's this pervasive attitude among senior neurologists that there's nothing you can do about a stroke, but that's not true today. They also don't realize that preventing complications can result in a reduction in disability." This can have significant implications for the patient.

In a prospective multicenter study of 311 patients admitted to hospitals in Scotland, Langhorne and colleagues2 found some type of complication in the charts of 265 (85%) of those persons. Pain was the single most common complication, reported by 43% of patients while in the hospital and 56% of those followed from discharge to 6 months. The authors noted that they observed a higher incidence of symptoms such as pain, depression, and anxiety than have previous investigators. They offered several reasons, including the subjective and nonspecific nature of those complaints, but they also suggested that those problems may simply have been underrecognized in previous studies.2

Initially after a stroke, neurologists focus on "hard signs" that are easy to follow, such as slurred speech and facial drooping, explained Kiwon Lee, MD, medical director of the Neurointensive Care Unit, Jefferson Medical College of Thomas Jefferson University in Philadelphia. "Often what's missed are the signs and symptoms of depression, such as emotional lability, loss of appetite, and decreased desire for an active social life," he explained. Other kinds of personality changes also are not unusual after a stroke: previously well-balanced persons may become angry, irritable, and impulsive, screaming at loved ones and caregivers or engaging in inappropriate behavior. "Mood disorders are quite common and often not addressed because physicians don't look for them."

Doctors may miss these symptoms because they're often transient, Lee added. "They come and go, and the patient himself may forget about them if he only sees the doctor 2, 3, or 6 months after discharge. Also, perhaps physicians are not asking the patients how their moods have been, whether they're feeling depressed or whether they're having an active social life. Maybe the crucial questions are not being asked, and if you don't look for it, you're not going to get it."

UTIs
Infections are among the most common stroke complications. Urinary tract infections (UTIs) occurred in 23% of the patients studied by Langhorne and colleagues,2 and other authors have noted their frequency as well.3-6 UTI was the single most frequent medical complication seen in a study of 1029 consecutive stroke patients admitted to the Rehabilitation Institute of Chicago, occurring in 31% of patients and handily outdistancing joint and soft tissue pain, the second most common complication, at 14%. Acute urinary retention occurred in another 5% of patients.3

UTI was seen in more than 17% of 1455 patients with ischemic stroke admitted to a Glasgow hospital. The main risk factors were female sex and a higher baseline NIH Stroke Scale (NIHSS) score, with high scores suggesting a greater degree of baseline deficit. UTI also was an independent risk factor for a poor outcome as measured by the NIHSS, Barthel Index assessing activities of daily living, and Modified Rankin Scale of deficit severity. The study authors noted that infections in general are the third most common complication of stroke and recommended close monitoring of high-risk patients.4

"Older adults in general and patients with stroke in particular have bladder problems," said Roth, who was the lead author of the Chicago study. Urinary retention, bladder abnormalities attributable to the stroke, and problems associated with indwelling catheters all increase the risk of UTI. In another study, he and his coauthors found that indwelling tubes in general were associated with greater stroke severity and disability, a higher frequency of complications, and longer hospital stays.5

According to Bayley, stroke location influences the risk of UTI. "It's most commonly associated with strokes affecting the middle cerebral artery, since that includes the frontal lobe, which coordinates bladder activity," he explained. On the other hand, a stroke in the brain stem can disrupt the coordination between bladder and sphincter function, which also sets up the patient for a UTI. Whenever a patient is immobile and spends a long time in bed, urine can pool in the bladder, creating a culture medium for bacteria.

PAIN
Pain in general and shoulder pain in particular is another common complication of stroke. Langhorne and colleagues noted shoulder pain in 9% of their hospitalized patients and unspecified "other" types of pain in another 34%. Pain prevalence seemed to grow after discharge, with 15% of patients complaining of shoulder pain and 41% of "other" types at 6-month follow-up. At 12 months, the prevalence of shoulder and "other" pain was 12% and 37%, respectively.2 Roth and colleagues3 reported joint and soft tissue pain in 14% of patients, making it the second most prevalent complication in their study, but they did not comment on other types of pain.

In a prospective study of 607 patients who were admitted to the hospital for a stroke or who suffered a stroke while an inpatient, at least 1 type of complication developed in 360 (59%) of patients; a painful shoulder developed in 27 patients (4%). This tended to be a late-developing complication, as was depression, unlike seizures and chest infections, which occurred earlier in the patients' course.6

Shoulder pain often goes unrecognized as a stroke complication, even though it is common and easy to prevent, Bayley pointed out. The cause is not completely understood, but it may be the result of a neuropathic pain syndrome, subluxation of the shoulder due to muscle weakness, or neglect if the patient is unaware of shoulder trauma. It might also arise from poststroke arthritis, said Mark Alberts, MD, professor of neurology and director of the Stroke Program at Northwestern Memorial Hospital in Chicago. "When movement is limited, the joint can freeze up from lack of use. That's why physical therapists have patients do range of motion exercises," he explained.

Whatever the cause, Bayley estimated that shoulder pain might develop in as many as 30% of stroke patients, even if it is not always reported. He recommends that it be treated aggressively because patients with shoulder pain experience poorer outcomes than those who avoid it.

HYPOPROTEINEMIA
There is a clear relationship between a patient's se-rum albumin concentration and clinical outcomes, although it is less clear whether hypoalbuminemia is a cause or a result of stroke. It may be both. Stroke patients often have low serum albumin levels, but this may be more a signal of chronically poor nutrition than a stroke complication. "Low albumin indicates that nutrition is not up to standard; it doesn't necessarily mean it was caused by the stroke or that it is related to the stroke," said Lee.

Roth and coauthors3 noted hypoalbuminemia in 709 (69%) of their patients and considered it a preexisting condition. "Some of these patients may have been malnourished before the stroke," he explained. "This takes a while to develop. It doesn't happen just from skipping a meal or two." Stroke-related dysphagia or depression may exacerbate an already fragile nutritional state. On the other hand, a patient may be perfectly able and willing to eat, only to be placed on no oral intake as soon as he or she is admitted to the stroke unit. "The professionals should be sensitive to the patient's need for nutrition right away," says Roth.

At least one study has suggested that nutritional status may suffer in the aftermath of a stroke. In 1998, Gariballa and colleagues7 reported on patients whose nutritional status was assessed within 48 hours of hospital admission and again after 2 and 4 weeks. The patients' overall nutritional status deteriorated throughout the study period, and hypoalbuminemia was highly significantly associated with the risk of infection and poor functional outcomes (P < .0001). Serum albumin level was also a good predictor of in-hospital functional disability and handicap, and it was a strong independent predictor of mortality at 3 months.7

In a later study, Dziedzic and colleagues8 measured serum albumin in 759 patients within 36 hours of stroke onset and then assessed outcomes 3 months later using the Modified Rankin Scale. Patients with a poor outcome at 3 months, defined as a Rankin Scale score greater than 3 or death, had a mean serum albumin level of 34 g/L, significantly less than the mean of 37 g/L measured in patients whose outcomes were better. They concluded that relatively high serum albumin levels decreases the risk of a poor outcome from acute stroke.8 These authors also have reported that high serum albumin levels reduce the risk of nosocomial pneumonia in this patient population.9

SLEEP APNEA
Sleep apnea is a risk factor for stroke, although whether it is also a complication is less clear. Arzt and colleagues10 conducted cross-sectional and longitudinal analyses on 1475 and 1189 persons, respectively, drawn from the general population. Each participant underwent polysomnography and was assessed for other stroke risk factors as well as any history of stroke. These examinations were repeated annually for 4 years. Subjects in the cross-sectional analysis who had evidence of sleep-disordered breathing had a risk of stroke more than 4 times greater than that of persons without breathing disturbances. In the longitudinal analysis, sleep-disordered breathing was associated with an increased risk of stroke, although it lost statistical significance after adjustment for age, sex, and body mass index. Nevertheless, the authors concluded that there was a strong association between moderate and severe sleep apnea and stroke and that sleep apnea may contribute to stroke development.10

In another prospective study of 1022 people, Yaggi and colleagues11 found a strong relationship between the risk of stroke or death from any cause and an apnea-hypopnea index greater than 5 (suggesting more than 5 sleep apnea episodes per hour) compared with an index of 2 or less. In this study, obstructive sleep apnea syndrome remained a significant risk factor even after adjustment for age, sex, body mass index, smoking, alcohol consumption, and the presence of diabetes and cardiovascular risk factors. The investigators concluded that sleep apnea significantly increases the risk of stroke or death from any cause, independent of other risk factors, including hypertension.11

Bayley estimates that 70% of stroke patients seen at the Toronto Rehabilitation Institute have sleep apnea. He recommends that polysomnography be performed on all new patients and that those who have sleep apnea be treated with continuous positive airway pressure.

PREVENTING COMPLICATIONS
"The focus should be on stroke prevention," Alberts maintained. "Screen people for risk factors such as hypertension, smoking, diabetes, and high cholesterol, and control them aggressively." If it's too late for that, "screen stroke patients early on for swallowing difficulties and maintain a high index of suspicion for pain and for infections such as UTIs and pneumonia. The earlier you can get an assessment from an interdisciplinary team, the better the outcomes," Bayley said.

Roth also recommended a proactive approach, saying, "Many complications are preventable through prompt recognition and institution of treatment."

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