Search

Anaemia is defined by the haemoglobin concentration in peripheral blood being below the normal 14 gm/dL (SD ± 2) for women, 16 gm/dL (SD ± 2) for men and 12 gm/dL (SD ± 2) for children. The number of red blood cells is also usually reduced, below the normal 4.8 × 106/mm3 (SD ± 0.6) for women and 5.4 × 106/mm3 (SD ± 0.9) for men. The haematocrit is the proportion of red blood cells in the blood – normally more than 40% for men and 37% for women. The other major red blood cell indices that may be helpful in the differential diagnosis of anaemia are: the mean corpuscular volume (MCV), which is the average red blood cell size and is normally 87 u3 (SD ± 5); the mean corpuscular haemoglobin (MCH), which is the amount of haemoglobin per cell, normally 29 pg of haemoglobin/cell (SD ± 2)

In the Balance This interactive case features a 71-year-old man who presented with a 3-day history of changes in mental status. Test your diagnostic and therapeutic skills at NEJM.org.

Presentation of Case A 28-year-old woman was admitted to the hospital because of ocular inflammation, fever, and headache. The patient had been well until three weeks earlier, when a cough developed, initially productive of yellow sputum, with rhinorrhea and a sore throat. The symptoms continued for about two weeks and were not affected by amoxicillin. About one week before admission, fever developed, and the patient's temperature rose as high as 40.6°C; the cough continued but became nonproductive. A rash was noted intermittently in both axillae, and the right axilla became reddened. About five days before admission, a frontal headache developed . . .

Presentation of Case A 61-year-old man was admitted to the hospital because of right hemiplegia, aphasia, and obtundation. According to the patient's family, he had been well at his home in Haiti until about one month earlier, when pain developed in his right leg. Two days later, an ultrasonographic examination of the leg revealed no abnormalities, and a physician advised him to take aspirin. The pain resolved, but three weeks before admission, headache, nausea, and vomiting developed and shortly thereafter disappeared; two days later, the patient had a problem with balance. An ultrasonographic study of the liver raised the possibility . . .

The Partners Neurology Residency Program spans two neurology departments in Boston. The neurology departments of the Brigham and Women's and Massachusetts General Hospitals comprise of 325 faculty members and 53 neurology residents. Given this large community and the vast number of opportunities that are available at these academic institutions, it is critical to have a system to disseminate information and inform the neurology community of important events. In the era of digital technology, email and web-based media provide an opportunity for efficient communication. One way in which this is accomplished is by means of a weekly newsletter detailing lectures, academic conferences and departmental meetings. This bulletin, our ‘Neurology Weekly Events,’ has become an important fixture in maintaining cohesion within the programme. Our weekly newsletter provides a comprehensive list of daily events for the upcoming week including time and …

Neurologic complications of infective endocarditis (IE) are common and frequently life threatening. Neurologic events are not always obvious. The prediction and management of neurologic complications of IE are not easily approached algorithmically, and the impact they have on timing and ability to surgically repair or replace the affected valve often requires a painstaking evaluation and joint effort across multiple medical disciplines in order to achieve the best possible outcome. Although specific recommendations are always tailored to the individual patient, there are some guiding principles that can be used to help direct the decision-making process. Herein, we review the pathophysiology, epidemiology, manifestations, and diagnosis of neurological complications of IE and further consider the impact they have on clinical decision making.

In this issue of Circulation , Jensen et al1 report that cognitive difficulties were no fewer when off-pump (OPCAB) versus conventional (CCAB) coronary artery bypass grafting was used. This important investigation, a substudy of the Best Bypass Surgery Trial, is a randomized prospective controlled trial that compares OPCAB with CCAB. Although the numbers seem relatively small (ie, 120 elderly patients with a men age of 76 years), the study was carefully powered to show differences in cognitive function at a mean of 103 days of follow-up. Although one could quibble with the details of the neuropsychological tests chosen (mini-mental state examination as a screening test for dementia after randomization but before inclusion, visual verbal learning, concept shifting, Stroop color word interference test, letter-digit coding), the main result is unequivocal. The incidence of cognitive decline was roughly 8%, and no difference between OPCAB and CCAB was found. This disappointing result raises important questions about the mechanisms of neurological injury caused by cardiac surgery and what future strategies might entail. Article p 2790 Early in the development of cardiac surgery, it was psychiatrists who first reported difficulties with thought content and process. Rizzo et al2 reported on 32 patients under the care of Lewis Dexter (cardiologist) and Dwight Harken (cardiac surgeon) who underwent “finger fracture” valvuloplasty surgery for rheumatic mitral valve disease at the Peter Bent Brigham Hospital in Boston. These psychiatrists applied analytical explanations (eg, hysterical fantasies as the heart as a sexual organ, transference to the surgeon, depersonalization, narcissism) to their findings of disordered thinking in many of their patients. Only 50 years later, these explanations sound amusingly antique, but they mark the first organized recognition that the brain could suffer serious damage as a result of cardiac surgery. The neurological complications of cardiac surgery fall into 2 …

Presentation of Case A 43-year-old woman was admitted to the hospital in early June because of possible adult respiratory distress syndrome. The patient had been in excellent health until nine days earlier, when she began to have low-grade fever, chilliness, and headache. On the next day, she slept excessively. One week before admission to this hospital, she vomited and lost consciousness for 15 seconds while kneeling. Later that day, an examination at another hospital revealed tender postoccipital lymph nodes; the white-cell count was 7600 per cubic millimeter. Her husband recalled that he had removed a tick from her neck about . . .

Neurological symptoms occur in approximately 20% of patients with Sjogren's syndrome, and may be the presenting manifestations of the disease. Here, we review several neurological conditions that can occur in Sjogren's syndrome: sensory ganglionopathy, painful small fibre neuropathy, and transverse myelitis (independently or as part of neuromyelitis optica). We present the symptoms, signs, differential diagnoses, recommended diagnostic evaluation, and treatment of each of these, highlighting the features that should alert neurologists to consider Sjogren's syndrome.

Objective. In uncontrolled clinical trials, negative extrathoracic pressure has been shown to be an effective respiratory support. We aimed to assess its role in the context of current neonatal intensive care. Design. A randomized controlled trial, with sequential analysis of matched pairs of infants. Matching was undertaken by stratified randomization from 15 groups divided according to gestational age, oxygen requirement, and whether patients were intubated at 4 hours of age. Setting. Two neonatal intensive care units. Patients. Two hundred forty-four patients (birth weight 1.53 ± 0.69 kg (mean ± SD); gestational age 30.4 ± 3.5 weeks) with respiratory failure. Interventions. Patients were randomized at 4 hours of age to receive either standard neonatal intensive care, or standard care plus continuous negative extrathoracic pressure (CNEP, -4 to -6 cmH2O) applied within a purpose-designed neonatal incubator. Outcome Scores. Clinical scores were calculated for each infant at 56 days of age, or death if earlier. Scores included measures for mortality, respiratory outcome, the presence of cerebral ultrasound abnormalities, patent arterial duct, necrotizing enterocolitis, and retinopathy. The treatment given for the higher score for each pair was recorded and the cumulative net number of pairs favoring CNEP plotted in the sequential analysis to provide an ethical early termination strategy. Individual components of the outcome score and other secondary measurements were analyzed on completion of the trial. Results. The sequential analysis reached a decision boundary after 122 out of a possible maximum of 124 pairs were completed. The overall outcome score showed an overall significant benefit for CNEP. Secondary analysis showed that the use of CNEP was associated with an increase in mortality, cranial ultrasound abnormalities, and pneumothoraces, which were not statistically significant. However, 5% fewer patients were intubated (95% confidence interval [CI], 0-10), and the total duration of oxygen therapy among surviving infants at 56 days was lower (20.5 days, compared with 38.9 in controls; difference 18.4 days, 95% CI 3.8 to 33.0). Among all infants, the mean total duration of oxygen therapy was 18.3 days among CNEP-treated infants compared with 33.6 days among the controls (difference -15.3 days, 95% CI -0.2 to -30.4). This reduction in mean levels is entirely attributable to substantially fewer patients requiring prolonged oxygen therapy, the median duration of treatment being very similar in the two groups. As a result, commensurately fewer surviving infants showed chronic lung disease of prematurity. Conclusions. The use of continuous negative pressure improves the respiratory outcome for neonates with respiratory failure.

The effect of the neck seal used in the application of negative extra-thoracic pressure ventilation was studied using near infrared spectroscopy. Changes in cerebral blood volume (CBV) were monitored during discontinuation of negative pressure and during removal of the neck seal. CBV increased by 0.17 ml 100 ml brain −1 (95% CI +0.0875 to +0.481) when negative pressure was discontinued. Removal of the neck seal had no significant effect on CBV. It is concluded that the neck seal does not cause significant jugular venous occlusion.

Some of the most common reasons for metabolic neurologic disturbances in the setting of a general hospital are frequently encountered electrolyte and related osmolality disorders. Hyperosmolality is usually related to hypernatremia and/or hyperglycemia. Identifying the cause and carefully calculating the water deficit is crucial to appropriate management. Hyponatremia may be hypertonic, isotonic, or hypotonic. When hypotonic, it may be hypervolemic, euvolemic, or hypovolemic in nature. Determining the precise nature of the hyponatremia allows the clinician to focus the therapy appropriately. The rate of development of hyponatremia is crucial to safe and appropriate treatment. In acutely developing hyponatremia, hypertonic saline is required, whereas in slowly developing hyponatremia, water restriction and slow correction is required to avoid the syndrome of osmotic demyelination. Disorders of potassium metabolism are also common electrolyte disorders seen in the general hospital. Appropriate diagnosis and management of hyperkalemia and hypokalemia are also discussed.

Kidney failure is one of the leading causes of disability and death and one of the most disabling features of kidney failure and dialysis is encephalopathy. This is probably caused by the accumulation of uremic toxins. Other important causes are related to the underlying disorders that cause kidney failure, particularly hypertension. The clinical manifestations of uremic encephalopathy include mild confusional states to deep coma, often with associated movement disorders, such as asterixis. Most nephrologists consider cognitive impairment to be a major indication for the initiation of renal replacement therapy with dialysis with or without subsequent transplantation. Sleep disorders, including Ekbom's syndrome (restless legs syndrome) are also common in patients with kidney failure. Renal replacement therapies are also associated with particular neurologic complications including acute dialysis encephalopathy and chronic dialysis encephalopathy, formerly known as dialysis dementia. The treatments and prevention of each are discussed.

Sudden unexpected death is a problem of major importance, but very little is known about its cause. Electrocardiographic abnormalities have been known to occur in the context of neurologic disease for a long time. This article discusses the neuroanatomy of the heart and lungs and neurogenic lung and heart disease. The four classes of causes of these abnormalities are catecholamine infusion, stress plus or minus steroids, nervous system stimulation, and reperfusion. These classes are tied together by a common thread, the essential feature of which is sympathetic overactivity with secondary catecholamine toxicity. A unifying hypothesis is proposed to explain all of the forms of sudden death based on the anatomic connection between the nervous system and the heart and lungs.

A number of physiologic phenomena during some apneic/cyanotic episodes in infants and young children cannot be explained sufficiently on the basis of a cessation or reduction in aveolar ventilation alone. These include (1) the extremely rapid development of hypoxemia during some episodes, (2) the occurrence of hypoxemic episodes despite continuous ventilation, (3) differences in the speed of desaturation between different forms of apneic episodes, (4) the presence of continued breathing efforts and yet absent airflow despite bypass of the upper airway, and (5) evidence that apnea and hypoxemia may begin simultaneously. Potential mechanisms to explain these phenomena include the sudden development of an unevenness in the matching between ventilation and lung perfusion, the flow of blood through unventilated areas of lung, and a sudden impairment in gas diffusion. Evidence from physiological and morphological studies suggests that all of these mechanisms, although to a different extent, may be involved in apneic/cyanotic episodes. The recognition that nonapneic mechanisms can cause sudden profound hypoxemia may alter our approach to the identification, treatment, and prevention of these episodes.

Stem cell transplants are established therapy for hematologic and solid tumor malignancies. Known neurological complications of stem cell transplantation include CNS infection, seizures, strokes, metabolic encephalopathy, and hemorrhage. We report two cases of autologous stem cell transplantation complicated by cerebral infarction and myocardial injury. We postulate that the cryopreservative dimethyl sulfoxide may be responsible.

Intestinal malabsorption is an impairment of one or more of the steps involved in normal digestion and absorption of nutrients. The neurologic manifestations of malabsorption are mostly related to the vitamin deficiency that may result, regardless of the underlying disease causing the malabsorption. Vitamins are biologically active organic compounds that are essential for normal growth, development, and health and that cannot be synthesized by the body. The four fat-soluble vitamins are A, D, E, and K, and the nine water-soluble vitamins are B 1 (thiamine), B 2 (riboflavin), niacin, B 6 (pyridoxine), folic acid, B 12 (cyanocobalamin), C (ascorbic acid), pantothenic acid, and biotin.

Organ transplantation, begun in the mid-twentieth century with renal transplantation, has burgeoned into one of the greatest advances in twentieth-century medicine. Advances in immunology have allowed longer survival for transplant recipients, but this has resulted in the emergence of a number of neurologic problems in these patients, most of which are presented to the primary care physician.

Hepatic and portosystemic encephalopathy are common medical conditions that face the primary care physician and specialist alike. They are closely related neuropsychiatric syndromes characterized by abnormal mental status occurring in patients with hepatic insufficiency or portosystemic shunts. They may complicate both acute and chronic liver disease.

Anemia General issues Anemia is present when the concentration of hemoglobin in the peripheral blood is below the normal range for the patient's age and sex (i.e. 14 ±2 gm/dl for women, 16±2 gm/dl for men and 12±2 gm/dl for children). When anemia is present, the red blood cell population is usually reduced. The normal red blood cell count is 4.8±0.6×10 6 /mm 3 , for women and 5.4±0.9×10 6 ,/mm 3 for men. The hematocrit indicates the proportion of red blood cells in the blood. Greater than 40% for men and 37% for women is considered normal. The major red blood cell indices, which may be helpful in the differential diagnosis of anemia are: the mean corpuscular volume (MCV) which is the average red blood cell size (normal is 87±5u 3 ); the mean corpuscular hemoglobin (MCH) which is the amount of hemoglobin per cell (normal is 29±2 pg of hemoglobin/cell); and the mean corpuscular hemoglobin concentration (MCHC) which is the average concentration of hemoglobin per cell (normal is 34±2%). These erythrocyte indices may be useful but it should be emphasized that they are averages and complete evaluation requires microscopic examination of the peripheral blood smear which will reveal evidence of red blood cell size (macrocytosis, microcytosis) and shape as well as evidence of the degree of maturity of the red blood cells (i.e. presence of reticulocytes or nucleated cells), the intensity of hemoglobin staining (hypochromia, normochromia or hyperchromia), or the presence of macrocytes, target cells, spherocytes, schistocytes or other abnormally shaped cells. In some situations, automated analysis of erythrocyte indices may reveal normal range results, but direct observation of the peripheral blood smear shows evidence of a dimorphic anemia (e.g. iron deficiency plus megaloblastic anemia) in which some cells are clearly microcytic and hypochromic and others are macrocytic, accounting for the normal indices which reflect an automated average of the two abnormalities. No analysis of anemia is complete without a direct observation of the peripheral blood smear by an experienced observer Neurological aspects of the anemias Non-specific neurologic effects of anemia There are very few neurological effects of anemia per se . Headache and lightheadedness may occur in severe anemias but these symptoms usually require that the hemoglobin concentration be reduced by at least one-half. In slowly developing anemias, many patients may have little or no neurological symptoms with hemoglobin concentrations as low as one-tenth normal.