Controversies in Parkinson's Disease

(Great Britian—The Practitioner, January 1999, p. 39) Parkinson's disease usually progresses slowly over 15 to 20 years, and the classic symptoms of rigidity and hypokinesia (with or without tremor) may be caused by several neurologic processes, making diagnosis difficult. One neuropathologic study showed that approximately one fourth of patients identified as having Parkinson's disease were incorrectly diagnosed. Neuroimaging is rarely useful in establishing the diagnosis, and because the diagnosis is made on the basis of clinical evidence, subspecialist consultation is frequently needed. Because all treatments are associated with significant side effects, therapy is usually deferred until patients have severe functional disability. Many patients manage well without therapy for several years. Levodopa therapy leads to dyskinesia and deterioration in approximately 10 percent of patients each year, but this rate is greater in younger patients. Selegiline was initially thought to be neuroprotective but was associated with an increased mortality rate in one large trial. Amantadine may improve dyskinesia but is less effective than levodopa and may cause confusion and skin disorders. Anticholinergics may relieve tremor, but these agents increase confusion and hallucinations in older patients and contribute to cognitive impairment in younger patients. New therapies based on dopamine agonists may provide effective monotherapy with acceptable side effects. Initial studies show that 60 percent of patients remain on these medications for at least three years, but that “rescue” levodopa was required to control symptoms in 40 percent of these patients.

Appropriate Diagnostic Tests for Fatigue

(Canada—Canadian Family Physician, February 1999, p. 373) Fatigue is common in primary care patients, but studies attempting to define the most probable underlying conditions and the optimal diagnostic strategy have provided conflicting results. Guidelines have been developed for the evaluation of patients who have fatigue of more than six months' duration, but there is no consensus as to the appropriate evaluation of fatigue of shorter duration. A Canadian study used an evidence-based approach to develop guidelines for the diagnostic investigation of fatigue lasting less than six months. A literature search yielded 15 articles that met quality criteria. Based on these studies, the authors recommend that all patients complaining of fatigue be screened for anxiety, depression, trauma and abuse. Patients should also undergo a physical examination and a focused history. Other investigations should only be pursued if indicated by specific features of the history or physical examination. Although the treatment of elderly patients was not a focus of the literature search, there is reasonable evidence that these patients are more likely to have physical causes of fatigue. The physician should consider routinely evaluating hemoglobin, white blood cells, erythrocycte sedimentation rate, and levels of thyroid-stimulating hormone and glucose in patients over 65 years of age with fatigue.

Communicating with Adolescents

(New Zealand—New Zealand Family Physician, February 1999, p. 16) Many physicians find it a challenge to communicate with adolescent patients. For optimal communication with adolescents, physicians should stay calm, use simple language and allow the conversation to proceed in small, gradual stages. Attention should be given to physical distance; sitting too close may make an adolescent uncomfortable. The mnemonic HEADS may assist in assessment by guiding questions to include: home environment; education, ethnicity and employment; activities with peers, anxiety and appetitite; drugs and alcohol, depression and delusions; suicide, safety and sexuality. Although physicians may be excellent communicators, major barriers for adolescents may exist in the organization of the practice, particularly in the attitude of reception and office staff.

Warfarin-Food Interactions

(China—Hong Kong Practitioner, January 1999, p. 11) Warfarin causes anticoagulation by antagonizing vitamin K, so dietary fluctuations in vitamin K content can dramatically influence anticoagulant control. Phylloquinone, the main dietary source of vitamin K₁, is found mainly in green leafy vegetables, certain legumes, and canola (rapeseed) and soybean oils. Vitamin K₂ (menaquinones) is found principally in animal livers and fermented foods such as cheese. Uncontrolled bleeding has occurred in anticoagulated patients as a result of excessive dietary intake of foods containing both phylloquinones and menaquinones. Other foods with an anticoagulant effect include garlic, avocado, brussels sprouts and raw onion. Although salicylates are usually found in medications, they occur naturally in certain foods and may interfere with anticoagulation.