Herpes simplex infections of the nervous system.

Dramatic progress has been made recently in diagnosing and treating herpes simplex virus encephalitis (HSVE). Advances in imaging technology have greatly enhanced our ability to diagnose the illness noninvasively. Acyclovir is of proven efficacy and is generally well-tolerated.

Sciatic nerve sarcoidosis: utility of magnetic resonance peripheral nerve imaging and treatment with radiation therapy.

Sarcoidosis may involve both the central and peripheral nervous system, although peripheral nerve manifestations are usually seen late in the disease. In this report, the authors describe a case of sarcoidosis in a 22-year-old woman who presented with a foot drop. Although results of conventional lumbar magnetic resonance (MR) imaging were normal, MR peripheral nerve imaging of the thigh showed a mass in the sciatic nerve indicating tumor.

Current therapy of multiple sclerosis.

The list of medications for both immune modulation and symptomatic relief continues to grow. Ideally, however, drug therapy should be part of a multidisciplinary approach that also includes such elements as patient education and physical therapy.

Cortical MRI findings associated with rapid correction of hyponatremia.

The authors describe two patients with clinical manifestations of the osmotic demyelination syndrome (ODS) and unusual MRI findings of gadolinium-enhancing peripheral cortical abnormalities. They propose that these represent extrapontine manifestations of ODS because neither patient had a notable hypoxic-ischemic insult. Recognizing this imaging appearance is important because prognosis in ODS may be less uniformly grim than for hypoxia-ischemia.

Intravascular lymphomatosis: contribution of cerebral MRI findings to diagnosis.

Intravascular lymphomatosis (IL) is a rare variant of non-Hodgkin's lymphoma with an unusual predilection for the central nervous system (CNS). Most cases are not diagnosed until postmortem because of variable clinical presentation and nonspecific laboratory findings. Neuroimaging findings vary widely and range from diffuse involvement of the deep white matter to infarct-like lesions.

Calciphylaxis mimicking dermatomyositis: ischemic myopathy complicating renal failure.

Background: Among the complications of chronic renal failure is a syndrome of medial calcification of small- to medium-sized arteries associated with ischemic necrosis of the skin and other organ systems, leading to gangrene and a poor prognosis. The syndrome has been reviewed in the renal, dermatologic, and surgical literature under the term calciphylaxis, which describes a postulated pathogenetic mechanism whereby sensitization to an endogenous or exogenous substance (such as parathyroid hormone) predisposes to calcium deposition after exposure to a challenging agent. Myopathy has rarely been reported as the presenting feature, and the syndrome has not been discussed in the neurologic literature.

Dizzy patients: the varieties of vertigo.

Some vertigo results from acute viral labyrinthitis or a cerebrovascular event; many cases are due to loose particulate matter within the semicircular canals. In the vast majority of patients, a careful history and appropriate clinical tests will suffice to identify the cause of the vertigo--and with benign paroxysmal positional vertigo, a simple clinical maneuver can also provide a cure.

Approach to the patient with migraine.

Women with migraine often experience a worsening of symptoms at menopause. Use of exogenous estrogens is not helpful and may even exacerbate the condition. Although initial pharmacologic management generally is focused on control of individual headaches, attempts to stabilize the underlying migraine mechanism through serotonin receptor downregulation are likely to provide a better outcome.

Herpes simplex virus genomes in human nervous system tissue analyzed by polymerase chain reaction.

Herpes simplex virus (HSV) is known to establish latency in human trigeminal ganglia. It has been speculated that the virus might also be present in latent fashion in normal human brain, where it might be responsible for conditions such as herpes simplex encephalitis, and less plausibly as a cause for multiple sclerosis or Alzheimer's disease. To test the possibility that HSV exists in normal human brain, we utilized the polymerase chain reaction to assess the frequency and distribution of HSV genomes in the nervous system tissues of patients dying of nonneurological causes.

Correlation between detection of herpes simplex virus in oral secretions by PCR and susceptibility to experimental UV radiation-induced herpes labialis.

We examined the oral secretions of 25 patients for herpes simplex virus (HSV) at the time of and following experimental UV radiation (UVR). HSV was detected in one or more oral secretion specimens in 5 of 12 (42%) cases by cell culture and in 8 of 12 (67%) cases by PCR. On the day of UVR, HSV was detected in 1 of 12 (8%) patients who developed a lip lesion and 2 of 16 (13%) patients who did not (the difference is not significant).

Symptomatic hyponatraemia: can myelinolysis be prevented by treatment?

The treatment of hyponatraemia is controversial because of the risk of causing central or extrapontine myelinolysis (EPM). Rapid correction with hypertonic saline to a low normal sodium level has its proponents; others feel that slow correction to below normal sodium values is preventative. Most investigators feel that overcorrection should be avoided.

Cerebrovascular syndromes following cardiac transplantation.

Between 1985 and 1990, there were 275 orthotopic cardiac transplantations performed on 263 patients. To determine the frequency and define the clinical spectrum of cerebrovascular disease among these patients, we followed them over an average period of 18.5 months (range, 1 to 59 months).

Aseptic meningitis following cardiac transplantation: clinical characteristics and relationship to immunosuppressive regimen.

Neurologic disorders are uncommon but alarming complications of cardiac transplantation. Of 29 patients from the Utah Cardiac Transplant Program (UCTP) who had lumbar puncture because of change in neurologic function, or to assess fever of uncertain etiology, CSF pleocytosis was present in 14 patients, 4 of whom had an active infectious process involving the nervous system. In 10 other patients, CSF pleocytosis with negative cultures appeared following treatment with OKT3 monoclonal antibody.

Porphyrin-laser photodynamic induction of focal brain necrosis.

A noninvasive photodynamic method has been developed to produce focal brain necrosis using porphyrin activated in vivo with laser light. After peripheral injection of the photosensitive porphyrin derivative, Photofrin I, mice were irradiated on the posterior lateral aspect of the head through the intact depilated scalp with 632 nm argon-dye laser light. Animals were studied at one, two and seven days after irradiation.