Heavy computer use, even up to seven hours per day, did not increase the risk of carpal tunnel syndrome, according to a study in the June 12 Neurology. Researchers from the Mayo Clinic surveyed 257 employees who were frequent computer users. Although nearly 30% of the employees reported hand paresthesias, only about 10% met clinical criteria for carpal tunnel syndrome, and in only 3.5% of those surveyed was the syndrome confirmed by nerve conduction studies. This incidence is similar to that found in the general population, the researchers reported.

Telomere position effect (TPE) plays a role in cellular aging, according to a study in the June 15 Science. Researchers at the University of Texas Southwestern Medical Center showed that a luciferase-containing piece of DNA inserted into human cells will express 10 times less luciferase than controls will when adjacent to a telomere. “We knew that when telomeres became too short, they caused cells to stop dividing, but there wasn’t a mechanism for how a cell could sense how long its telomeres were before they became too short. TPE can do that. It can let a cell know how old it is so that it could change its behavior before it became senescent,” said researcher Dr. Woodring Wright.

For the first time, stress has been linked to increased stroke risk in a population of middle-age white men. According to a report in the June Stroke, men with an excessive systolic reactivity to stress have a 72% greater risk of any stroke and an 87% greater risk of ischemic stroke relative to less reactive men. The population-based, longitudinal study of 2,303 Finnish men (mean age, 52.8) also concluded that low socioeconomic status presents an added risk. It is unknown whether women, nonwhites, or younger people would have the same risk.

Elderly women have better mental function than do elderly men, despite lower levels of education, according to a report in the June Journal of Neurology, Neurosurgery and Psychiatry. Nearly 600 Dutch men and women, all age 85, underwent neuropsychiatric testing. Limited formal education was significantly more common among the women than the men, but the women outscored the men in tests of mental speed and memory. Good mental speed was found in 33% of the women and 28% of the men. Good memory was found in 41% of the women and 29% of the men. Researchers from Leiden University Medical Center suggest that biological differences (eg, relative absence of cardiovascular disease among the women) could account for the sex differences in mental decline.

A new genetic risk factor for Alzheimer’s disease was reported in the July Molecular Psychiatry. Results of a decade-long research study involving more than 300 first-degree relatives of 189 patients with Alzheimer’s disease identified a risk locus on a small area of chromosome 10 that, when combined with the apolipoprotein E e4 allele, significantly increases a person’s risk for developing Alzheimer’s disease. This combination of genes produced a 16-fold increase in the risk of Alzheimer’s disease among first-degree relatives of a patient with the disease.

Results of two randomized, placebo-controlled, double-blind trials of ceftriaxone (2 g/d for 30 days) followed by doxycycline (200 mg/d for 60 days) in patients with chronic, refractory Lyme disease indicate that while these patients suffer pain and other disabling symptoms, a 90-day course of both intravenous and oral antibiotics was no better than placebo at improving chronic musculoskeletal pain or neurocognitive symptoms. Although both trials were identical in design, one trial enrolled 78 chronic Lyme disease patients who tested positive for Borrelia burgdorferi while the other trial enrolled 51 persons with chronic symptoms but no evidence of B burgdorferi antibodies. Results of both studies were published in the July 12 New England Journal of Medicine.

Many patients who return to driving after traumatic brain injury report problems that could significantly affect their ability to drive, according to a study in the June Journal of Neurology, Neurosurgery and Psychiatry. During a 2.5-year period, researchers followed 563 adults with traumatic brain injury (of which 381 were drivers before the injury and 139 had returned to driving). Of those who returned to driving, nearly half reported behavior problems such as anger, aggression, and irritability and 64% reported memory problems. More than 25% also reported visual and/or concentration problems. Such problems were reported equally by drivers and ex-drivers, the researchers noted. Patients should be assessed for both mental and physical status before returning to driving after a head injury, they concluded.

A new study may be able to help predict which children with epilepsy will not respond to the most common medications, and thus which children will be candidates for more aggressive approaches. More than 600 children with newly diagnosed epilepsy were followed for at least 18 months. According to study results published in the June 12 Neurology, three factors were identified as increasing the risk of an intractable course of epilepsy. Those patients with cryptogenic/symptomatic generalized epilepsy have the greatest risk. Also at high risk are those whose seizures exceeded one per month when they first developed. Children with focal slowing on EEG are also more likely to have intractable epilepsy.

Newborns with hypoplastic left heart syndrome (HLHS) are less likely to have early neurologic problems, such as seizures or comas, if their heart condition is diagnosed prenatally, according to a study in the June Pediatrics. The study looked at 216 infants with hypoplastic left heart syndrome, 79 of them having been diagnosed before birth. Prenatal diagnosis was associated with less adverse perioperative neurologic events and reduced early neurologic morbidity. “If diagnosis of HLHS is delayed, severe organ damage may occur, especially to the brain,” said lead author William T. Mahle, MD. “We hope to show that prenatal diagnosis, in addition to reducing short-term neurological problems, also improves long-term functioning.”

Lamotrigine is less likely than valproate to cause polycystic ovary syndrome, according to a study presented at the 53rd Annual Meeting of the American Academy of Neurology. The open-label, observational study followed 119 women taking lamotrigine monotherapy and 103 women taking valproate monotherapy for a period of eight months to five years. “Many women with epilepsy receive their treatment from primary care and community physicians who may not be aware of recent information showing that infertility and menstrual disturbances may be associated with some antiepileptic drugs,” said researcher Dr. Martha Morrell.

A test of neck movement may be able to predict which patients with whiplash injuries will be disabled a year later, according to study in the June 26 Neurology. The test of how far the neck can move can predict future disability with 91% accuracy, researchers reported. The prediction is even more accurate—up to 94%—by factoring in pain intensity and number of other problems associated with the whiplash. The study, which included 141 patients with acute whiplash injuries and 40 patients with acute ankle injuries as controls, found that patients with less neck movement, greater pain intensity, and more other problems (eg, dizziness, nausea, blurred vision) were more likely to be disabled a year after the accident.

Hind leg function can be partially restored in rats that underwent spinal cord transection in infancy, according to a study in the June Spine. However, the restored function does not result from regeneration of a direct pathway between the brain cortex and the corticospinal tracts. Rather, rats that regained walking ability had regeneration of subcortical pathways originating from the brainstem. While human muscle function cannot be restored by similar means, this study demonstrates a direct relationship between regeneration of specific spinal cord tracts and restoration of walking ability and it verifies the value of muscle-evoked potentials in confirming that specific spinal cord tracts have regenerated.

A single in vivo exposure to cocaine can elicit long-term potentiation of certain receptor-mediated currents at excitatory synapses onto dopamine cells in the ventral tegmental area, according to the study in the May 31 Nature. “The single exposure appears to hijack the brain’s normal molecular mechanisms of memory formation for around a week,” said researcher Antonello Bonci, MD. He went on to say that “the study shows that the capacity for strengthening connections between nerve cells—the basis for learning and memory—can be usurped by drugs of abuse.”

In people ages 90 and older, the presence of the apolipoprotein E e4 (APOE e4) allele is linked to an increased probability of Alzheimer’s disease, according to a report published in the June 26 Neurology. The study of 532 Finnish residents, ages 85 and older, showed that approximately 63% of patients with APOE e4 had Alzheimer’s disease, compared with 20% among those who did not carry the e4 allele. When the patients were older than 90, the prevalence increased to 71% and 22%, respectively. “This significant difference shows that the connection between APOE e4 and Alzheimer’s disease lasts a lifetime,” commented study author Matti J. Haltia, MD, PhD. “While everyone is at an increased risk for Alzheimer’s disease as they grow older, some people with this genetic factor appear to be on a different probability slope, starting earlier,” Dr. Haltia said.

NR