AN ALZHEIMER’S PREVENTION STRATEGY

People with Alzheimer’s disease are more likely to have had less mentally demanding careers than those without Alzheimer’s disease, according to a study published in the August 10 Neurology. Kathleen Smyth, PhD, of Case Western Reserve University School of Medicine and the University Hospitals of Cleveland, and colleagues examined 122 people with Alzheimer’s disease and 235 people without the disease—all older than 60. They asked subjects or their family members to report the name of the company or institution in which they worked, the type of occupation, the dates they were employed, and their most important activities or duties. They then compared the occupational demands of the two study groups while in their 20s, 30s, 40s, and 50s.

Researchers found that, while in their 20s, people with Alzheimer’s disease held jobs with the same mental demands as those without the disease. In later decades, however, people in the control group held jobs with higher mental demands while those with Alzheimer’s disease remained at about the same level.

Results also indicated that subjects with Alzheimer’s disease held jobs that were more physically demanding than did those in the control group. In addition, motor and social demands did not seem to differ significantly between subjects with Alzheimer’s disease and those without the disease.

In their report, the researchers offered several possible explanations for the association between Alzheimer’s disease and mentally demanding jobs. Researchers said the results “could suggest a relatively early influence of Alzheimer’s disease neuropathology on subjects’ capacity to pursue mentally demanding occupations.” The investigators also theorized that occupations with high levels of mental demands might result in increased neuronal activity, which may help to resist the effects of Alzheimer’s disease.

Another possible explanation is that “jobs with higher mental demands require the development and ongoing use of skills that enhance an individual’s ability to perform well on the types of tests typically used in the diagnosis of Alzheimer’s disease. If this is the case, individuals with Alzheimer’s disease neuropathology may go undetected until the disease is much farther along than in those whose jobs pose lower mental demands.”

One major limitation to the study was that researchers did not control for socioeconomic status, which can produce variations in income, access to health care, and quality of nutrition. Each of these variables could be responsible, in part, for the results of the current study.

Smyth KA, Fritsch T, Cook TB, et al. Worker functions and traits associated with occupations and the development of Alzheimer’s disease. Neurology. 2004;63:498-503.

ORGAN TRANSPLANT RECIPIENTS WITH WEST NILE VIRUS INFECTION DEVELOP SEVERE NEUROLOGIC DAMAGE

Organ transplant recipients who become infected with West Nile virus are at an increased risk of developing more severe neurologic damage, according to B. K. Kleinschmidt-DeMasters, MD, of the University of Colorado Health Sciences Center, and colleagues. Their research, which is published in the August Archives of Neurology, is the largest report to date of naturally acquired West Nile virus in transplant recipients.

The researchers identified 11 transplant recipients—seven women and four men age 32 to 62 years—who received kidney, liver, stem cell, lung, or kidney/pancreas transplants five months to 15 years prior to the onset of West Nile virus infection.

Physician and hospital medical records were reviewed to gather data regarding clinical symptoms and neurologic illness. Results of serologic tests, cerebrospinal fluid examinations, magnetic resonance imaging, and electroencephalography were examined as well.

The investigators found that out of 10 patients who developed meningoencephalitis, three developed acute flaccid paralysis as well. One patient developed acute flaccid paralysis without encephalitis, and six patients had movement disorders such as tremor, myoclonous, or parkinsonism.

Seven out of eight patients who received cranial magnetic resonance imaging showed abnormalities. In addition, cerebrospinal fluid examinations showed the presence of pleocytosis in all patients. Ten patients had elevated cerebrospinal fluid protein levels and normal cerebrospinal fluid glucose levels. Cerebrospinal fluid cytologic examination “showed small lymphocytes, varying numbers of neutrophils, monocytes, and reactive and atypical lymphocytes” in five patients. Researchers also indicated that “cerebrospinal fluid West Nile virus antibody was detectable in six of nine tested patients.”

Medical records indicated that two patients died after hospital admission. Autopsy results, however, were only available for one patient, who died of acute pneumonia 17 days after initial hospitalization. Results indicated “areas of necrosis and macrophage influx in nearly every sampled section of the subcortical gray matter, brainstem, cerebellum, and spinal cord.” Additional areas of the brain contained abnormalities as well.

The researchers concluded that “naturally acquired West Nile virus encephalitis in transplant recipients shows diagnostic, clinical, and laboratory features similar to those reported in nonimmunocomprised individuals, but neuroimaging, electroencephalography, and autopsy results verify that these patients develop neurological damage at the severe end of the spectrum.”

Kleinschmidt-DeMasters BK, Marder BA, Levi ME et al. Naturally acquired West Nile virus encephalomyelitis in transplant recipients. Arch Neurol. 2004;61:1210-1220.

DEEP BRAIN ELECTRODES STIMULATE BETTER SEX IN PATIENTS WITH PARKINSON’S DISEASE

Italian researchers conducted the first study of the impact of deep brain stimulation on sexual well-being in patients with Parkinson’s disease and reported that the procedure “appears to affect sexual functioning in a small but positive way”—at least in men. The women in the study showed no change in sexual well-being, noted Lorys Castelli, PhD.

Dr. Castelli, of the Department of Psychology at the Center for Cognitive Science in Turin, and colleagues examined 31 patients with Parkinson’s disease (21 men) who had bilateral implantation for subthalamic nucleus deep brain stimulation. The mean age of the cohort was 61.7; average disease duration was 16.9 years. Mean Hoehn and Yahr stage disability rating was 4 prior to surgery and 2.5 postsurgery. Participants were examined one month before and nine to 12 months after surgery; there was no evidence of urogenital dysfunction on interview or physical examination, and all patients were married at the time of the evaluation, Dr. Castelli noted.

Participants completed a reduced form of the Golombok Rust Inventory of Sexual Satisfaction called the Sexual Functioning Inventory (SFI). The SFI rates seven items for each sex—infrequency, noncommunication, dissatisfaction, avoidance, nonsensuality, premature ejaculation, impotence, vaginismus, and anorgasmia—on a scale of 15 to 60, with higher scores representing more sexual problems. All patients were evaluated in the medication-on condition prior to surgery and in the stimulation-on/medication-on condition at postoperative follow-up. Depression and anxiety were evaluated using the Beck Depression Inventory and the State-Trait Anxiety Inventory.

The investigators found that the total SFI score was lower for both men and women preoperatively and postoperatively (30.3 versus 28.6, respectively, for men; 33.1 versus 32.0, respectively, for women), though this finding was not significant for either group. However, male patients showed significant improvement only on the SFI dissatisfaction item, Dr. Castelli noted.

When the sample was subdivided according to age, men ages 60 and younger showed significant change preoperatively and postoperatively (34.7 versus 28.0, respectively) compared with men older than 60, the researchers said. Significant improvement was found in SFI infrequency score, while dissatisfaction and avoidance scores showed a trend to positive change.

Beck depression scores showed a nonsignificant decrease between preoperative and postoperative evaluations in men and women, as did State-Trait anxiety scores. There was no significant correlation between sexual functioning and any other variables, the investigators reported.

“The most important finding of this study was the significant benefit, even if small, on sexual functioning after subthalamic nucleus deep brain stimulation that was obtained by male patients with Parkinson’s disease [younger than 60]” Dr. Castelli wrote in the September Journal of Neurology, Neurosurgery, and Psychiatry. “As no cognitive side effects occurred in our patients, we can exclude disinhibition, a potentially relevant factor, as an explanation for our findings,” the researchers noted. Though they could not advance any concrete explanation for their findings, they hypothesized that motor improvement may have had an indirect effect on change in sexual functioning. “Further studies assessing sexual function in the spouses of patients with subthalamic nucleus deep brain stimulation could improve our understanding of the changes that occur in the marital relationship after surgery.”

Castelli L, Perozzo P, Genesia ML, et al. Sexual well being in parkinsonian patients after deep brain stimulation of the subthalamic nucleus. J Neurol Neurosurg Psychiatry. 2004;75:1260-1264.

HOSPITALIZED STROKE PATIENTS OFTEN TREATED FOR HYPERTENSION AGAINST MEDICAL GUIDELINES

About 65% of acute ischemic stroke patients are likely to be treated with antihypertensive agents during the first four days of hospitalization despite current guidelines that recommend against treating all but the most severe cases of hypertension during the first few days following a stroke. Because lowering blood pressure in the acute setting can result in the prolongation or worsening of stroke symptoms, the American Stroke Association began forming guidelines for the use of antihypertensive therapy in 1994.

In a recent study—published in the July 27 Neurology—a team of investigators led by Peter Lindenauer, MD, of Baystate Medical Center in Springfield and Tufts University School of Medicine in Medford, reviewed medical records of 154 stroke patients. At the time of the patients’ hospitalization, a version of the 1994 guidelines had been distributed to physicians. The investigators sought “to determine whether the use of antihypertensive agents was consistent with current guideline recommendations.”

Results indicated that 100 (65%) of the 154 patients were treated with antihypertensive agents during the first four days of hospitalization. Thirty-three of the 79 patients who had received medication prior to admission had their regimens intensified, while twenty-seven patients who had not been treated with antihypertensive medication prior to admission had treatment initiated within the first few days of hospitalization.

Researchers found that 17% of patients who continued medication, 36% of patients who had medication intensified, and 26% of patients who had medication initiated had hypertension severe enough to warrant antihypertensive treatment.

They commented that “several factors may help to explain the discrepancy … between guideline recommendations and actual physician practice.” One important factor is that 47% of the patients used antihypertensive agents for the management of conditions such as coronary artery disease, heart failure, diabetes mellitus, and renal disease.

Another factor is that because “hypertension is an important factor in the etiology of stroke, physicians may believe that mild to moderate elevations in blood pressure need to be treated acutely to prevent extension or worsening of the stroke symptoms,” the investigators noted.

The researchers emphasized in their report that “greater efforts should be made to educate physicians about potential risks associated with this practice.”

Lindenauer PK, Mathew MC, Ntuli TS, et al. Use of antihypertensive agents in the management of patients with acute ischemic stroke. Neurology. 2004;63:318-323.

NR

—Karen L. Spittler

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