Items in AFP with MESH term: Nervous System Diseases
Vitamin B12 Deficiency - Article
ABSTRACT: Vitamin B12 (cobalamin) deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of neuropsychiatric disorders. The role of B12 deficiency in hyperhomocysteinemia and the promotion of atherosclerosis is only now being explored. Diagnosis of vitamin B12 deficiency is typically based on measurement of serum vitamin B12 levels; however, about 50 percent of patients with subclinical disease have normal B12 levels. A more sensitive method of screening for vitamin B12 deficiency is measurement of serum methylmalonic acid and homocysteine levels, which are increased early in vitamin B12 deficiency. Use of the Schilling test for detection of pernicious anemia has been supplanted for the most part by serologic testing for parietal cell and intrinsic factor antibodies. Contrary to prevailing medical practice, studies show that supplementation with oral vitamin B12 is a safe and effective treatment for the B12 deficiency state. Even when intrinsic factor is not present to aid in the absorption of vitamin B12 (pernicious anemia) or in other diseases that affect the usual absorption sites in the terminal ileum, oral therapy remains effective.
Initial Evaluation of Vertigo - Article
ABSTRACT: Benign paroxysmal positional vertigo, acute vestibular neuronitis, and Meniere's disease cause most cases of vertigo; however, family physicians must consider other causes including cerebrovascular disease, migraine, psychological disease, perilymphatic fistulas, multiple sclerosis, and intracranial neoplasms. Once it is determined that a patient has vertigo, the next task is to determine whether the patient has a peripheral or central cause of vertigo. Knowing the typical clinical presentations of the various causes of vertigo aids in making this distinction. The history (i.e., timing and duration of symptoms, provoking factors, associated signs and symptoms) and physical examination (especially of the head and neck and neurologic systems, as well as special tests such as the Dix-Hallpike maneuver) provide important clues to the diagnosis. Associated neurologic signs and symptoms, such as nystagmus that does not lessen when the patient focuses, point to central (and often more serious) causes of vertigo, which require further work-up with selected laboratory and radiologic studies such as magnetic resonance imaging.
ABSTRACT: Recreational scuba diving has become a popular sport in the United States, with almost 9 million certified divers. When severe diving injury occurs, the nervous system is frequently involved. In dive-related barotrauma, compressed or expanding gas within the ears, sinuses and lungs causes various forms of neurologic injury. Otic barotrauma often induces pain, vertigo and hearing loss. In pulmonary barotrauma of ascent, lung damage can precipitate arterial gas embolism, causing blockage of cerebral blood vessels and alterations of consciousness, seizures and focal neurologic deficits. In patients with decompression sickness, the vestibular system, spinal cord and brain are affected by the formation of nitrogen bubbles. Common signs and symptoms include vertigo, thoracic myelopathy with leg weakness, confusion, headache and hemiparesis. Other diving-related neurologic complications include headache and oxygen toxicity.
ABSTRACT: Physicians may encounter patients with a collection of psychologic disorders that present with neurologic symptoms or signs, yet have no identifiable structural or functional etiology within the nervous system. These disorders comprise the so-called pseudoneurologic syndromes, which can mimic almost any organic disease. A careful history and physical examination often can identify the psychologic origin of the symptoms. Presenting syndromes can include pseudoparalysis, pseudosensory syndromes, pseudoseizures, pseudocoma, psychogenic movement disorders and pseudoneuro-ophthalmologic syndromes. These presentations may be distinguished from organic disease by observing signs and symptoms or eliciting test responses that are nonphysiologic and incompatible with organic disease. Once a pseudoneurologic syndrome is identified, patients require compassionate and understanding care to resolve underlying emotional problems.