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Chlamydia
pneumoniae does not appear to play a role in the development of multiple
sclerosis,
according to a report in the January 11 Neurology. Neither viable
C pneumoniae nor C pneumoniae DNA was detected in the cerebrospinal
fluid of any of the 99 patients with multiple sclerosis or other neurologic
diseases who participated in the study. Furthermore, metronidazole, which
was found to be effective in a previous case study, had no activity against
C pneumoniae in vitro. Inconsistent methodology and cross-reactivity
to other bacteria could explain the disparity in results. "It's much
too soon to put multiple sclerosis patients on antibiotics for Chlamydia
pneumoniae," said study author Margaret Hammerschlag, MD.
Older women
with type 2 diabetes are at a higher risk for major cognitive decline,
indicated a
longitudinal population-based study of 682 white women. Having diabetes
for more than 15 years was associated with a 57% to 114% greater risk of
major cognitive decline. Women with diabetes had lower scores on three tests
of cognitive function and experienced an accelerated cognitive decline over
time, according to a report in the January 24 Archives of Internal Medicine.
In an accompanying editorial, David Bennett, MD, noted that the cognitive
decline described in this study is too small to be detected by clinicians
on a case-by-case basis. However, treatments will develop from an improved
understanding of the neurophysiologic association between diabetes and cerebrovascular
disease, he predicted.
Spontaneous
internal carotid artery dissection is rare but treatable in children, according
to a research letter in the January 26 JAMA. A 13-year-old boy presented
to an emergency department with a severe left-sided throbbing headache that
had developed suddenly. A few hours later, he experienced right-side numbness
and a tingling sensation that spread from his fingers to his arm. An MRI
scan and angiogram revealed the dissection. The patient responded within
24 hours to anticoagulation and remained symptom-free one month later.
Temporary
loss of the ability to sneeze
is associated
with lateral medullary syndrome, according to a report of four consecutive
cases published in the January 25 Neurology. Each patient had unilateral
infarction of the brain stem and cerebellum in the territory of the ipsilateral
posterior inferior cerebellar artery. "The patient felt the ticklish
feeling in his nose signaling a sneeze; the buildup would peter out before
the explosive completion of the sneeze, leaving him feeling dissatisfied,"
said study author Mark Hersch, MD, PhD. "Some of my patients have been
amazed and relieved to hear that other patients have experienced the same
symptom."
Treating elderly
hypertensive patients to reduce diastolic blood pressure to below 65 mm
Hg may actually increase the risk of stroke,
according to
a prospective study published in the December issue of Hypertension.
In treated hypertensive patients, a J-shaped relationship was found between
blood pressure and the risk of stroke. Patients with a diastolic blood pressure
less than 65 mm Hg were at a greater risk of stroke than patients in the
65 to 74 mm Hg range. A higher risk was associated with diastolic blood
pressure of more than 75 mm Hg. The therapeutic goal of "the lower
the better" may not be the optimal strategy for blood pressure management
in the elderly, the authors concluded.
Individuals
who grew up in small, suburban families during the early 20th century are
at a lower risk for the development of Alzheimer's disease, according
to a University of Washington study in the January 25 Neurology.
Interviews with 393 patients and 377 control subjects indicated that the
risk for developing Alzheimer's disease was 39% higher for those who grew
up with five or more siblings, and that it was also higher for those who
grew up in a city or on a farm. The areas of the brain that show the earliest
signs of Alzheimer's disease—the hippocampal formation, intracortical association
areas, and reticular formation—are the same areas that are the slowest
to mature during childhood and adolescence, the authors wrote. The association
of lower risk of Alzeimer's disease in small, suburban families could reflect
the benefits of higher socioeconomic status—improved nutrition and less
exposure to infectious disease—they concluded. The researchers also noted
that number of siblings and area of residence were clearer demarcations
of socioeconomic status in the early 20th century.
Enteroviral
ribonucleic acids were found in the spinal cords of 15 of 17 patients with
amyotrophic lateral sclerosis
(ALS); however
enteroviral ribonucleic acid is not conclusively implicated in the development
of ALS, reported European investigators. Enteroviral ribonucleic sequences
were detected in the spinal cords of 15 (88.3%) of the 17 ALS patients and
in only one (3.4%) of the 29 controls. According to the report in the January
11 Neurology, enteroviral sequences were located in neuronal cell
bodies of the anterior horns of the spinal cord, suggesting that the viral
infection is somehow associated with the abnormal immunologic response and
neuronal death observed in patients with ALS.
Adults who
were born small for gestational age (SGA) are less likely to hold professional
or managerial jobs
than adults
who were in the normal range of weight at birth. However, there are no long-term
social or emotional consequences, according to the 26-year follow-up of
the 1970 British Birth Cohort, published in the February 2 JAMA.
The results of a questionnaire completed by 7,470 SGA and control adults
indicate no differences between the birth-weight groups in years of education
completed or hours of work performed weekly. Although SGA adults were as
likely to be married and satisfied with life, "every effort should
be made to provide SGA children with an enriched environment to minimize
the long-term negative effects," the authors advised.
The increase
in symptoms reported by Lyme disease patients is similar to that reported
by controls,
according to
a longitudinal, community-based study in the February 2 JAMA. Although
69% of the 678 patients with suspected Lyme disease in the study reported
difficulty performing daily activities and an increased frequency of symptoms
such as pain and fatigue, very few (19%) attributed their symptoms to Lyme
disease. Furthermore, the frequency of symptoms among a subset of patients
with a confirmed diagnosis was similar to that of matched control subjects.
"The prognosis for most patients with Lyme disease who receive conventional
antimicrobial treatment is excellent," the authors concluded. In an
accompanying editorial, Pierce Gardener, MD, warned that "without a
serologic criterion standard, there is no valid way to address issues of
asymptomatic or atypical infection for long-term outcomes." In this
study, patients with suspected Lyme disease who reported increased symptoms
did not meet the Centers for Disease Control case definition, thus suggesting
that the entire spectrum of Lyme disease is not recognized, he said. More
sensitive diagnostic tests are needed to avoid unwarranted use of antibiotics
for the patient whose clinical presentation is nonspecific, he concluded.
Positioning
or stimulation of respiration during sleep may contribute to the prevention
of sudden unexpected death in epilepsy (SUDEP),
according to
a report in the February Journal of Neurology, Neurosurgery and Psychiatry.
Although most SUDEP deaths are unwitnessed, in an evaluation of the circumstances
that surround SUDEP, researchers identified and questioned 15 witnesses
(11% of the sample). Twelve deaths were associated with convulsive seizures,
one patient collapsed following a generalized seizure, one collapsed after
an aura, and one died in a probable postictal state. Most subjects (12)
had experienced respiratory difficulty, which supports the theory that both
central and obstructive apnea may play an important role in SUDEP.
Brain
activity is altered in the sleep-deprived,
according to
a functional MRI study in the February 10 issue of Nature. During
verbal learning tests, the temporal lobe was activated in rested subjects
but not in sleep-deprived subjects. The prefrontal cortex became more active
as the subject's sense of sleepiness increased. Also, the parietal lobes
were more active in subjects deprived of sleep. These changes in activity
may reflect the brain's ability to compensate for the effects of sleep deprivation,
the authors suggested.
The incidence
of sleep disturbance in children is higher than expected,
according to
a study published in the February issue of Developmental and Behavioral
Pediatrics. After questioning parents, children, and teachers, the researchers
found that 37% of 494 school-age children had at least one sleep-related
problem. Issues such as bedtime resistance, sleep anxiety, breathing difficulties,
night waking, bedwetting, sleepwalking, and daytime sleepiness can have
a negative impact on children's daily lives, the authors said.
Golf ball
injuries may cause post-traumatic seizures
without causing
posttraumatic amnesia, skull fracture, or dural tear, according to authors
who described four cases in the February Journal of Neurology, Neurosurgery
and Psychiatry. Two patients experienced acute extradural or cortical
hematoma, the third experienced a minor depressed fracture and contusion,
and the fourth experienced localized intracranial hematoma. Golf balls are
able to transmit a considerable amount of mechanical energy at a small site
of impact, the researchers noted.
An
FDA advisory committee recommended approval of Novantrone
(mitoxantrone
for injection concentrate) for the treatment of selected patients with multiple
sclerosis. The FDA will consider the recommendation of the Peripheral and
Central Nervous System Drugs Advisory Panel in its final review of the new
drug application. In a phase III trial, treatment with Novantrone reduced
the annual relapse rate by 65%, compared with placebo, in patients with
worsening relapsing-remitting and secondary progressive multiple sclerosis.
At six months, treated patients had a 64% reduction in 1-point Expanded
Disability Status Scale deterioration.
—Shauna Kubose
Senior Associate Editor
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