RESUMEN
BACKGROUND: Human T-lymphotropic virus (HTLV) type I is the causative agent of HTLV-associated myelopathy (HAM)/tropical spastic paraparesis, and a number of HAM cases with HTLV-II infection have also been reported. However, despite some reports, it is unclear whether HTLV-I or -II infection is associated with other neurologic manifestations. METHODS: An analysis of medical histories and screening neurologic examinations from a prospective cohort of 153 HTLV-I, 388 HTLV-II, and 810 HTLV-seronegative individuals followed up for means of 11.5, 12.0, and 12.2 years was performed. Participants diagnosed with HAM were excluded. We calculated odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for age, sex, race or ethnicity, income, educational attainment, body mass index, alcohol and cigarette consumption, injection drug use, diabetes, and hepatitis C virus status, using generalized estimating equations for repeated measures. RESULTS: HTLV-I and -II participants were more likely than seronegative participants to have leg weakness (ORs 1.67 [95% CI 1.28-2.18] and 1.44 [1.16-1.78]), impaired tandem gait (ORs 1.25 [95% CI 1.07-1.47] and 1.45 [1.27-1.64]), Babinski sign (ORs 1.54 [95% CI 1.13-2.08] and 1.51 [1.18-1.93]), impaired vibration sense (ORs 1.16 [95% CI 1.01-1.33] and 1.27 [1.14-1.42]), and urinary incontinence (ORs 1.45 [95% CI 1.23-1.72] and 1.70 [1.50-1.93]). For both HTLV-I and -II participants, higher odds of sensory neuropathy by monofilament examination were no longer significant after adjustment for confounding. CONCLUSIONS: These results provide strong evidence that human T-lymphotropic virus (HTLV)-I and -II are associated with a spectrum of predominantly motor abnormalities in patients without overt HTLV-associated myelopathy. Further investigation of the clinical course and etiology of these abnormalities is warranted.
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Infecciones por HTLV-I/epidemiología , Infecciones por HTLV-II/epidemiología , Virus Linfotrópico T Tipo 1 Humano , Virus Linfotrópico T Tipo 2 Humano , Trastornos de la Destreza Motora , Enfermedades del Sistema Nervioso , Paraparesia Espástica Tropical , Adolescente , Adulto , Anciano , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Infecciones por HTLV-I/diagnóstico , Infecciones por HTLV-II/diagnóstico , Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Virus Linfotrópico T Tipo 2 Humano/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Trastornos de la Destreza Motora/diagnóstico , Trastornos de la Destreza Motora/epidemiología , Trastornos de la Destreza Motora/virología , Enfermedades del Sistema Nervioso/diagnóstico , Enfermedades del Sistema Nervioso/epidemiología , Enfermedades del Sistema Nervioso/virología , Paraparesia Espástica Tropical/diagnóstico , Paraparesia Espástica Tropical/epidemiología , Estudios Prospectivos , Adulto JovenRESUMEN
BACKGROUND: Sciatica without evidence of lumbosacral root compression is often attributed to piriformis syndrome. However, specific diagnostic tools have not been available to demonstrate sciatic nerve entrapment by the piriformis muscle. OBJECTIVE: To evaluate the use of magnetic resonance (MR) neurography in identifying abnormalities of the sciatic nerve in patients with unexplained sciatica. DESIGN: Case series from a retrospective medical record review. PATIENTS: Fourteen patients with sciatic distribution pain and normal results on MR imaging for lumbosacral radiculopathy were referred for MR neurography of the lumbosacral plexus and sciatic nerves. RESULTS: In 12 patients, MR neurography demonstrated increased fluid-attenuated inversion recovery signal in the ipsilateral sciatic nerve. In most patients, this abnormal signal was seen at the sciatic notch, at or just inferior to the level of the piriformis muscle. To date, 4 patients have undergone surgical decompression, with excellent relief of symptoms in 3 of them. CONCLUSION: Magnetic resonance neurography often identifies an abnormal increased signal in the proximal sciatic nerve in patients with extraspinal sciatica and allows more accurate diagnosis of sciatic nerve entrapment in suspected cases.
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Nervio Ciático/patología , Nervio Ciático/fisiopatología , Neuropatía Ciática/diagnóstico , Neuropatía Ciática/fisiopatología , Ciática/diagnóstico , Ciática/fisiopatología , Adulto , Anciano , Femenino , Humanos , Hipertrofia/diagnóstico , Hipertrofia/patología , Hipertrofia/fisiopatología , Isquion/patología , Plexo Lumbosacro/patología , Plexo Lumbosacro/fisiopatología , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Músculo Esquelético/patología , Músculo Esquelético/fisiopatología , Atrofia Muscular/diagnóstico , Atrofia Muscular/patología , Atrofia Muscular/fisiopatología , Pelvis/patología , Pelvis/fisiopatología , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Ciática/etiologíaRESUMEN
Although neuralgic amyotrophy can selectively affect discrete components of the brachial plexus including individual peripheral nerves, involvement of an individual nerve fascicle is rare. Discrete fascicular musculocutaneous neuropathy as a manifestation of neuralgic amyotrophy has not previously been reported to our knowledge. We report two cases of otherwise typical neuralgic amyotrophy with isolated brachialis muscle wasting. Abnormal spontaneous activity, motor unit remodeling, or both, was observed only in the brachialis muscle. Lateral antebrachial cutaneous nerve conduction studies were normal. These cases serve to broaden the spectrum of the clinical presentation of neuralgic amyotrophy.
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Neuritis del Plexo Braquial/patología , Neuropatías del Plexo Braquial/patología , Músculo Esquelético/patología , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Músculo Esquelético/inervación , Atrofia Muscular/patología , Conducción NerviosaRESUMEN
The reliability of motor unit number estimation (MUNE) for assessment of the long-term course of ALS is dependent on the reproducibility of the technique. We report our results with the statistical method of MUNE on the ulnar nerve/hypothenar muscle in 16 ALS patients who were studied on 52 occasions. On each occasion, MUNE was performed twice with one electrode placement and once with a different placement. For each MUNE, mean surface motor unit potential amplitude was determined within three different recording ranges or windows at different stimulus intensities. The MUNE results had excellent reproducibility with coefficients of variation of 19% and test-retest correlation coefficients from 0.75 to 0.86. With examination of sources for variability, the reproducibility of statistical MUNE is not affected by minor variation in stimulation and recording electrode placement but may be improved by modifying methods for recording window selection. The high reproducibility of statistical MUNE supports its reliability for estimating the rate of motor unit loss in ALS.
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Esclerosis Amiotrófica Lateral/patología , Neuronas Motoras/patología , Músculo Esquelético/patología , Algoritmos , Esclerosis Amiotrófica Lateral/fisiopatología , Recuento de Células , Estimulación Eléctrica , Electrodos , Humanos , Potenciales de la Membrana/fisiología , Neuronas Motoras/fisiología , Músculo Esquelético/inervación , Músculo Esquelético/fisiopatología , Reproducibilidad de los ResultadosRESUMEN
Low back pain may be of local origin, referred to the spine, or associated with pain in the lower limbs. This review discusses the pathophysiology, clinical presentation, and differential diagnosis of acute low back pain and proposes an algorithmic approach to investigation and management. The proportion of patients with serious underlying causes (e.g., cancer, infection, fracture) increases with age, and clinical assessment is directed at identification of these disorders. Most patients have nonspecific findings, do not require special investigation, and respond well to conservative treatment. Patients with suspicious features on history and physical examination require further investigation and individualized management.
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Algoritmos , Dolor de la Región Lumbar/terapia , Diagnóstico Diferencial , Humanos , Dolor de la Región Lumbar/clasificación , Dolor de la Región Lumbar/diagnóstico , Dolor de la Región Lumbar/etiologíaRESUMEN
Orthostatic hypotension is defined as a decrease of at least 20 mm Hg in systolic blood pressure when an individual moves from a supine position to a standing position. Nonneurogenic causes of orthostatic hypotension are related to cardiac pump failure, reduced intravascular volume, venous pooling or a medication side effect. Neurogenic causes include both central and peripheral nervous system lesions. The diagnostic evaluation requires a systematic review of medications and coexisting medical conditions along with a neurologic examination to search for treatable factors that may be contributing to orthostatic hypotension. Specific testing of autonomic function is useful for detecting subclinical orthostatic hypotension or for monitoring autonomic function over a period of time. Treatment is directed at improving the patient's symptoms rather than achieving arbitrary blood pressure goals.
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Hipotensión/etiología , Hipotensión/terapia , Diagnóstico Diferencial , HumanosRESUMEN
A randomized double-blinded study was performed on 20 normal volunteers to evaluate 2 different techniques of single-injection digital anesthesia. Single-injection transthecal digital block technique was used to anesthetize 1 index finger and single-injection subcutaneous technique to block the other index finger. Pain and light touch were evaluated and sensory nerve-conduction studies were performed on both index fingers. These data were obtained prior to the nerve blocks and then at 10-minute intervals until recovery from the anesthesia. The method of anesthesia was found to have no effect on the distribution, onset, and duration of anesthesia. Median and radial nerve sensory nerve action potential amplitude reductions following digital anesthesia were also not influenced by the technique of anesthesia. Single-injection subcutaneous block was found to be easier to administer and to produce less pain during and 24 hours after injection than did the single-injection transthecal technique.
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Dedos/inervación , Lidocaína , Bloqueo Nervioso/métodos , Adulto , Método Doble Ciego , Femenino , Humanos , Inyecciones , Inyecciones Subcutáneas , Masculino , Nervio Mediano/efectos de los fármacos , Nociceptores/efectos de los fármacos , Umbral del Dolor/efectos de los fármacos , Nervio Radial/efectos de los fármacos , Umbral Sensorial/efectos de los fármacos , Tendones , Tacto/efectos de los fármacosRESUMEN
Clinical neurologists in the health care system of the future should have a multifaceted role. Advances in the basic understanding of the nervous system and therapeutics of neurologic disease have created, for the first time in human history, an ethical imperative to correctly diagnose neurologic disease. In many situations, the neurologists may function as a consultant and principal physician for patients with primary nervous system disorders including Parkinson's disease, multiple sclerosis, Alzheimer's disease, epilepsy, migraine, cerebrovascular disease, movement disorders, and neuromuscular disease. Other important roles for neurologists include the training of future physicians, both neurologists and primary care physicians, the application of cost-effective approaches to care, and the support of health care delivery research and academic programs that link basic research efforts to the development of new therapy. To be successful, future residency training programs should include joint certification opportunities in both neurology and general medicine, and training programs for clinical investigators should be expanded. Despite its threats to specialists, managed care should also provide opportunities for new alliances among neurologists, other specialists, and primary care physicians that will both improve patient care and increase efficiency and cost-effectiveness.
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Predicción , Neurología/tendencias , Consultores , Análisis Costo-Beneficio , Atención a la Salud/economía , Medicina Familiar y Comunitaria/educación , Humanos , Enfermedades del Sistema Nervioso/diagnóstico , Enfermedades del Sistema Nervioso/terapia , Neurología/economía , Neurología/educación , Neurología/estadística & datos numéricosRESUMEN
We describe six young patients with insidiously progressive, painless weakness in the distribution of a single major lower extremity nerve. No cause could be found despite extensive evaluation, including surgical exploration. At the time of diagnosis, all patients had weakness and three patients had sensory loss. In all cases, electromyography revealed a chronic axonal mononeuropathy without conduction block or focal conduction slowing. Magnetic resonance, computed tomographic, and ultrasound imaging studies did not identify a region of nerve swelling, mass, or compression. At surgical exploration, the nerve appeared atrophic in two patients, indurated in one patient, and normal in two patients. Biopsy specimens obtained from two abnormal nerves revealed either wallerian degeneration or endoneurial fibrosis. The clinical features of these patients comprise an unusual clinical entity with no known cause or treatment.
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Enfermedades del Sistema Nervioso/diagnóstico , Potenciales de Acción , Adolescente , Adulto , Niño , Electromiografía , Femenino , Nervio Femoral/fisiopatología , Humanos , Pierna/inervación , Masculino , Enfermedades del Sistema Nervioso/fisiopatología , Nervio Peroneo/fisiopatología , Nervio Ciático/fisiopatología , Nervio Tibial/fisiopatologíaRESUMEN
This study of quantitative electromyography examines the influence of sample size on motor unit action potential (MUAP) tolerance limits, intertrial variability, and diagnostic sensitivity. We recorded 20 randomly selected MUAPs from the biceps muscle twice in 21 normal subjects, and once in 10 patients with myopathy. The 95% tolerance limits for mean total duration in normal subjects progressively narrowed from 6.6 to 14.2 ms for 5 MUAPs to 7.4 to 13.0 ms for 20 MUAPs. The 95% tolerance limits for intertrial variability were +/-22% for mean total duration of 20 MUAPs. Larger sample size had a greater effect on reducing intertrial variability than on narrowing 95% tolerance limits for amplitude and area. Quantitative EMG results for duration supported the presence of myopathy in 2 of 10 patients with analysis of 5 MUAPs, and 9 patients with analysis of 20 MUAPs. Although analysis of 5 potentials may be adequate for diagnosis occasionally, quantitative analysis of 20 MUAPs narrows tolerance limits, reduces intertrial variability, and improves diagnostic sensitivity.
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Electromiografía/métodos , Neuronas Motoras/fisiología , Potenciales de Acción/fisiología , Adulto , Femenino , Humanos , Masculino , Enfermedades Musculares/diagnóstico , Sensibilidad y EspecificidadRESUMEN
PURPOSE: Little information is available concerning the clinical importance of cerebral infarction in patients with acquired immunodeficiency syndrome (AIDS). The purpose of this retrospective study was two-fold: (1) to determine the frequency and clinical characteristics of cerebral infarction and transient neurologic deficits (TNDs) among patients with AIDS; and (2) to identify specific patient subgroups at risk for such complications and whether there were underlying associated diseases requiring specific therapy. PATIENTS AND METHODS: Neurology inpatient and consult service records, neuropathology reports, and the University of California, San Francisco, AIDS computerized registry were used in identifying study cases. Information on demographic background, associated clinical diagnoses, presenting neurologic symptoms and signs, laboratory results, pathologic findings, and clinical follow-up was obtained from each patient's medical record. RESULTS: Twenty-five patients with AIDS (mean age, 38) having clinical or pathologic findings suggestive of focal cerebral ischemia or infarction were identified. Ten patients had non-hemorrhagic cerebral infarctions, 13 had acute TNDs, and two had both. Cerebral infarction was associated with central nervous system (CNS) infections (cryptococcus, four; tuberculosis, one; zoster vasculitis, one) and cardiogenic embolism (one). TNDs were associated with toxoplasmosis (four), cerebral infarction (two), cryptococcal meningitis (one), vasculitis (one), and CNS Kaposi's sarcoma (one). A presumptive cause was absent in five cases of cerebral infarction and eight of TND. All five patients with pathologically proven macroscopic cerebral infarcts were diagnosed clinically before death. CONCLUSIONS: We conclude the following: (1) AIDS patients, especially given their young age, appear to be increased risk for cerebral infarction and TND. (2) Cerebral infarction and TND may be the initial presentation of AIDS. (3) TND and cerebral infarction often signify treatable CNS infection among AIDS patients. (4) The causes of AIDS-related cerebral infarction and TND are unknown in many cases.
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Síndrome de Inmunodeficiencia Adquirida/complicaciones , Infarto Cerebral/etiología , Ataque Isquémico Transitorio/etiología , Adulto , Infarto Cerebral/epidemiología , Criptococosis/complicaciones , Humanos , Ataque Isquémico Transitorio/epidemiología , Meningitis/complicaciones , Persona de Mediana Edad , Factores de Riesgo , San Francisco , Toxoplasmosis/complicacionesRESUMEN
Hemoperfusion over cellulose-coated activated charcoal was used to treat a patient with severe doxepin overdose. Noncardiogenic pulmonary edema (NCPE) developed temporally in relation to the procedure. In this case, NCPE may have been from complement activation by the cellulose-coated charcoal column.