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1.
Brain ; 129(Pt 3): 767-77, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16418180

RESUMEN

Dysarthria is a frequent symptom in cerebral ischaemia. However, speech characteristics of these patients have not previously been investigated in relation to lesion site in a prospective study. We investigated the auditory perceptual features in 62 consecutive patients with dysarthria due to a single, non-space-occupying cerebral infarction confirmed by MRI. Standardized speech samples of all patients were stored within 72 h after stroke onset using a digital tape recorder. Speech samples were assessed independently by two experienced speech therapists, who were unaware of the clinical and neuroradiological findings, using an interval scale ranging from 0 to 6. Separately assessed were features of articulation, phonation, prosody, and the global severity for a total of 31 items. Extracerebellar infarctions (85.5%) were located in the lower motor cortex (14.5%), striatocapsular region (46.8%) and base of the pons (24.2%). Isolated cerebellar infarctions were present in 14.5% of patients. There was a strong correlation between the findings of both examiners, showing identical scores, or only minor differences (<1 on the assessment scale) for 80% of all items. The average severity of dysarthria was 2.9 +/- 1.3. Articulatory abnormalities were the predominant deviation characteristics, affecting in particular the production of consonants. However, phonatory and prosodic abnormalities were also frequently observed speech characteristics. As revealed by factor analysis of speech characteristics the total severity of dysarthria was mainly influenced by the impairment of articulation. Speech parameters describing characteristics of articulation and prosody showed significant side-to-side and area differences, while this effect was lacking for any voice parameter. Left cerebral lesions showed a more severe overall impairment of speech and articulation, independent of lesion topography. Thirty-eight of 62 patients were available for follow-up. Speech evaluation showed normal speech within weeks in 15 out of 38 patients (39.5%). In the other 23 patients overall severity of dysarthria was mild. This is the first prospective study which describes speech characteristics of dysarthria due to acute unilateral cerebral infarctions. We could demonstrate that dysarthria in extracerebellar infarctions was more frequently caused by left-sided lesions and that the severity of dysarthria was more pronounced in left-sided lesions independent from lesion topography. All extracerebellar lesions were located along the course of the cortico-bulbar tract fibres. Compatible with a common pathophysiological basis of dysarthria in these patients, none of the 31 speech items differed significantly between subcortical and brainstem lesions.


Asunto(s)
Infarto Cerebral/complicaciones , Disartria/etiología , Lateralidad Funcional , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Trastornos de la Articulación/etiología , Mapeo Encefálico/métodos , Infarto Cerebral/patología , Disartria/patología , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Percepción del Habla , Medición de la Producción del Habla , Tomografía Computarizada por Rayos X , Calidad de la Voz
2.
Neurology ; 64(4): 716-8, 2005 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-15728299

RESUMEN

Body lateropulsion may occur without signs of vestibular dysfunction and vestibular nucleus involvement. The authors examined 10 such patients with three-dimensional brainstem mapping. Body lateropulsion without limb ataxia reflected an impairment of vestibulospinal postural control caused by a lesion of the descending lateral vestibulospinal tract, whereas body lateropulsion with limb ataxia was probably the consequence of impaired or absent proprioceptive information caused by a lesion of the ascending dorsal spino-cerebellar tract.


Asunto(s)
Ataxia/etiología , Síndrome Medular Lateral/fisiopatología , Mapeo Encefálico , Trastornos de Deglución/etiología , Diagnóstico Diferencial , Imagen de Difusión por Resonancia Magnética , Síndrome de Horner/etiología , Humanos , Síndrome Medular Lateral/diagnóstico , Síndrome Medular Lateral/etiología , Estudios Prospectivos , Trastornos de la Sensación/etiología , Insuficiencia Vertebrobasilar/complicaciones , Insuficiencia Vertebrobasilar/fisiopatología , Enfermedades Vestibulares/diagnóstico
3.
Brain ; 128(Pt 2): 386-94, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15601661

RESUMEN

Our current understanding of brainstem reflex physiology comes chiefly from the classic anatomical-functional correlation studies that traced the central circuits underlying brainstem reflexes and establishing reflex abnormalities as markers for specific areas of lesion. These studies nevertheless had the disadvantage of deriving from post-mortem findings in only a few patients. We developed a voxel-based model of the human brainstem designed to import and normalize MRIs, select groups of patients with or without a given dysfunction, compare their MRIs statistically, and construct three-plane maps showing the statistical probability of lesion. Using this method, we studied 180 patients with focal brainstem infarction. All subjects underwent a dedicated MRI study of the brainstem and the whole series of brainstem tests currently used in clinical neurophysiology: early (R1) and late (R2) blink reflex, early (SP1) and late (SP2) masseter inhibitory reflex, and the jaw jerk to chin tapping. Significance levels were highest for R1, SP1 and R2 afferent abnormalities. Patients with abnormalities in all three reflexes had lesions involving the primary sensory neurons in the ventral pons, before the afferents directed to the respective reflex circuits diverge. Patients with an isolated abnormality of R1 and SP1 responses had lesions that involved the ipsilateral dorsal pons, near the fourth ventricle floor, and lay close to each other. The area with the highest probabilities of lesion for the R2-afferent abnormality was in the ipsilateral dorsal-lateral medulla at the inferior olive level. SP2 abnormalities reached a low level of significance, in the same region as R2. Only few patients had a crossed-type abnormality of SP1, SP2 or R2; that of SP1 reached significance in the median pontine tegmentum rostral to the main trigeminal nucleus. Although abnormal in 38 patients, the jaw jerk appeared to have no cluster location. Because our voxel-based model quantitatively compares lesions in patients with or without a given reflex abnormality, it minimizes the risk that the significant areas depict vascular territories rather than common spots within the territory housing the reflex circuit. By analysing statistical data for a large cohort of patients, it also identifies the most frequent lesion location for each response. The finding of multireflex abnormalities reflects damage of the primary afferent neurons; hence it provides no evidence of an intra-axial lesion. The jaw jerk, perhaps the brainstem reflex most widely used in clinical neurophysiology, had no apparent topodiagnostic value, probably because it depends strongly on peripheral variables, including dental occlusion.


Asunto(s)
Infartos del Tronco Encefálico/diagnóstico , Tronco Encefálico/fisiopatología , Reflejo Anormal , Adulto , Anciano , Anciano de 80 o más Años , Parpadeo , Infartos del Tronco Encefálico/fisiopatología , Electromiografía , Femenino , Humanos , Maxilares/fisiopatología , Imagen por Resonancia Magnética , Masculino , Músculo Masetero/fisiopatología , Persona de Mediana Edad
4.
Nervenarzt ; 75(4): 341-6, 2004 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-15088089

RESUMEN

The aim of this study was to evaluate the applicability, sensitivity, and predictive power of diffusion-weighted MR imaging (DWI) in the diagnosis of vertebrobasilar infarction. From 1997 to 2002, we prospectively recruited 268 patients with acute signs and symptoms suspective of vertebrobasilar ischemia. The patients underwent biplanar EPI-T2 and EPI DWI within 24 h after onset of symptoms and high-resolution MRI as a control within 7 days. One hundred twenty-one patients had additional CT scanning. The DWI revealed acute vertebrobasilar infarction in 71.0%. The mean time exposure of DWI was 8 min and thus no more than that of CT imaging. It showed significantly more acute lesions than CT imaging (28.0%), but additional high-resolution MRI was not able to reveal more lesions than DWI alone. Even in 42 patients with reversible brainstem or cerebellar symptoms classified as TIA or PRIND, DWI demonstrated acute ischemia in 42.8%. Sixty-three patients with optimal final diagnosis of vertebrobasilar ischemia had normal DWI. One week after onset of symptoms, 88.9% of these patients had recovered completely or showed minimal symptoms. Therefore, DWI is a sensitive indicator of acute vertebrobasilar ischemia. It is no more time-consuming than CT imaging, and normal DWI is a predictor of good clinical outcome in patients with brainstem or cerebellar infarction.


Asunto(s)
Imagen de Difusión por Resonancia Magnética/métodos , Insuficiencia Vertebrobasilar/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Radiografía , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Insuficiencia Vertebrobasilar/diagnóstico por imagen
5.
Muscle Nerve ; 29(5): 663-9, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15116369

RESUMEN

The pattern of upper-limb muscle activation following painful stimulation has not been clarified in detail. We investigated the short-term inhibitory and excitatory effects of painful electrical digital stimulation on the motoneuron pools of distal and proximal upper-limb muscles. Transcranial magnetic stimulation (TMS) was used as test stimulus, and painful digital nerve stimulation as conditioning stimulus for motor evoked potential (MEP) recordings over the abductor digiti minimi (ADM), abductor pollicis brevis (APB), biceps brachii (BB), and deltoid muscles. Inhibition of the conditioned MEP response was most prominent in the distal muscles, whereas BB and deltoid muscles were only weakly inhibited. The mean MEP response over APB decreased with painful cutaneous stimuli, showing maximum inhibition (by 82%) at interstimulus intervals (ISIs) of 50 ms. Inhibition in the ADM was maximal (49%) but less pronounced at an ISI of 40 ms. The BB and deltoid muscles showed inhibition by 25% and 29%, respectively. Significant facilitation was present in BB and deltoid muscles by 43% and 41% at an ISI of 100 ms, but not in the smaller hand muscles. The observed pattern of upper-limb muscle activation corresponds to the protective withdrawal reflex and the neuronal basis of the observed short-term modulation of motor activity is compatible with a spinal or brainstem pathway.


Asunto(s)
Brazo/fisiología , Potenciales Evocados Motores/fisiología , Músculo Esquelético/fisiología , Neuronas Aferentes/fisiología , Dolor/fisiopatología , Adulto , Análisis de Varianza , Estimulación Eléctrica/métodos , Femenino , Humanos , Masculino , Corteza Motora/fisiología , Factores de Tiempo
6.
J Neurol Neurosurg Psychiatry ; 75(2): 250-5, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14742599

RESUMEN

OBJECTIVES: To study the incompletely understood sympathoexcitatory pathway through the human brain stem, using a new method of three dimensional brain stem mapping on the basis of digitally postprocessed magnetic resonance imaging (MRI). METHODS: 258 consecutive patients presenting with acute signs of brain stem ischaemia underwent biplane T2 and EPI diffusion weighted MRI, with slice orientation parallel and perpendicular to a transversal slice selection of the stereotactic anatomical atlas of Schaltenbrand and Wahren, 1977. The individual slices were digitally normalised and projected onto the appropriate slices of the anatomical atlas. For correlation analysis lesions were imported into a three dimensional model of the human brain stem. RESULTS: 31 of the 258 patients had Horner's syndrome caused by acute brain stem ischaemia. Only four of the patients with Horner's syndrome had pontine infarctions, 12 had pontomedullary lesions, and 15 had medullary lesions. Correlation analysis showed significantly affected voxels in the dorsolateral medulla but not in the pons. A statistical comparison with infarct topology in patients with medullary lesions but without Horner's syndrome indicated that involvement of the medial and ventral part of affected voxels located in the ventrolateral medullary tegmentum was specific for Horner's syndrome. CONCLUSIONS: Based on this first in vivo topodiagnostic study, the central sympathoexcitatory pathway probably descends through the dorsal pons before converging on specific generators in the ventrolateral medullary tegmentum at a level below the IX and X nerve exits.


Asunto(s)
Encefalopatías/diagnóstico , Encefalopatías/fisiopatología , Mapeo Encefálico/métodos , Tronco Encefálico/fisiopatología , Vías Nerviosas/fisiopatología , Sistema Nervioso Simpático/fisiopatología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad
8.
J Anxiety Disord ; 17(4): 369-88, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12826087

RESUMEN

Two hundred and two consecutive patients with dizziness were evaluated using blind neuro-otological testing and examination, blind psychiatric examination, including structured interviews (according to DSM-IV), the Symptom Check-List (SCL 90 R), and the State-Trait Anxiety Inventory (STAI). In 28% of the patients (N=50) dizziness was of organic origin (O group); in 55.3% (N=99) of psychogenic origin (P group) and in 16.8% comorbid psychiatric disorders were found (Mixed group). In 5.3% (N=10) neither organic nor psychiatric results could be found, which could explain the dizziness (Ideopathic group). Compared with the Organic group the patients with psychiatric disorders (P and Mixed group) had much more extensive workups for dizziness, intense emotional distress (anxiety, depression), greater handicaps, and high somatization scores. In the P and Mixed groups three main subgroups of psychiatric disorders could be found: anxiety (N=56), depressive (N=20), and somatoform disorders (N=53). Patients with anxiety and depressive disorders showed the greatest emotional distress and handicaps. The results indicate that psychiatric disorders, above all anxiety disorders, should be included in the differential diagnosis in patients with a long duration of dizziness and great handicaps. An interdisciplinary treatment (including psychiatric treatment) would be superior to an exclusive somatic one.


Asunto(s)
Trastornos de Ansiedad/complicaciones , Mareo/complicaciones , Trastornos Mentales/complicaciones , Adolescente , Adulto , Anciano , Trastornos de Ansiedad/psicología , Diagnóstico Diferencial , Femenino , Alemania , Humanos , Masculino , Trastornos Mentales/psicología , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Estrés Psicológico/complicaciones , Enfermedades Vestibulares/complicaciones
9.
Acta Neurol Scand ; 106(3): 155-8, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12174175

RESUMEN

OBJECTIVE: To look for possible effects of polychlorinated dioxins and furans (PCDD/F) on cranial nerve function. MATERIAL AND METHODS: Clinical and neurophysiological examinations [visual and brainstem auditory evoked potentials (VEP and BAEP), blink reflex] in 121 PCDD/F exposed workers of one pesticide producing plant. RESULTS: BAEP abnormalities were more frequent in workers with chloracne (6 of 33 workers, 18.2%) than in those without chloracne (7 of 84, 8.3%), but this was not statistically significant (chi2: 2.33). VEP abnormalities were seen in one worker with and two without chloracne. Clinically visual functions were normal except in one worker, who was amaurotic since birth. Blink reflex abnormalities without corresponding clinical findings were observed in two patients without chloracne. CONCLUSION: Severe exposure to PCDD/F is not followed by clinical signs of cranial nerve dysfunction but may create an increased risk for abnormal BAEP findings, which were more than twice as common in workers with chloracne. Although this difference did not reach statistical significance, it cannot exclude a toxic effect of PCDD/F, as statistical significance is difficult to achieve with such small numbers of workers. In none of the workers, BAEP abnormalities were accompanied by clinical signs of hearing dysfunction.


Asunto(s)
Nervios Craneales/fisiopatología , Dioxinas/efectos adversos , Furanos/efectos adversos , Exposición Profesional , Adulto , Anciano , Parpadeo , Industria Química , Potenciales Evocados Auditivos del Tronco Encefálico/efectos de los fármacos , Potenciales Evocados Visuales/efectos de los fármacos , Femenino , Audición/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/inducido químicamente , Enfermedades Profesionales/complicaciones , Reflejo/efectos de los fármacos
10.
Hum Mutat ; 20(2): 127-32, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12124993

RESUMEN

Hereditary spastic paraplegias (HSP) comprise a genetically and clinically heterogeneous group of neurodegenerative disorders characterized by progressive spasticity and hyperreflexia of the lower limbs. Autosomal dominant hereditary spastic paraplegia 4 linked to chromosome 2p (SPG4) is the most common form of autosomal dominant hereditary spastic paraplegia. It is caused by mutations in the SPG4 gene encoding spastin, a member of the AAA protein family of ATPases. In this study the spastin gene of HSP patients from 161 apparently unrelated families in Germany was analyzed. The authors identified mutations in 27 out of the 161 HSP families; 23 of these mutations have not been described before and only one mutation was found in two families. Among the detected mutations are 14 frameshift, four nonsense, and four missense mutations, one large deletion spanning several exons, as well as four mutations that affect splicing. Most of the novel mutations are located in the conserved AAA cassette-encoding region of the spastin gene. The relative frequency of spastin gene mutations in an unselected group of German HSP patients is approximately 17%. Frameshift mutations account for the majority of SPG4 mutations in this population. The proportion of splice mutations is considerably lower than reported elsewhere.


Asunto(s)
Adenosina Trifosfatasas/genética , Análisis Mutacional de ADN/métodos , Genes Dominantes/genética , Paraplejía Espástica Hereditaria/genética , Adolescente , Adulto , Edad de Inicio , Niño , Preescolar , Deleción Cromosómica , Proteínas Contráctiles/genética , ADN/genética , Exones/genética , Femenino , Variación Genética/genética , Alemania , Humanos , Masculino , Persona de Mediana Edad , Mutación/genética , ARN Mensajero/biosíntesis , Espastina
11.
J Neurol Neurosurg Psychiatry ; 72(5): 572-5, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-11971039

RESUMEN

OBJECTIVES: To evaluate the sensitivity of diffusion weighted magnetic resonance imaging (MRI) for the diagnosis of clinically suspected reversible ischaemic deficits of the brainstem. METHODS: A total of 158 consecutive patients presenting with acute signs of brainstem dysfunction were investigated using EPI diffusion weighted MRI within 24 hours of the onset of symptoms. High resolution T1 and T2 weighted imaging was performed as a follow up after a median of six days. RESULTS: Fourteen of the 158 patients had a complete clinical recovery within 24 hours (transitory ischaemic attack (TIA)), and 19 patients recovered in less than one week (prolonged reversible neurological deficit (RIND)). Diffusion weighted MRI showed acute ischaemic deficits in 39% of patients with transient neurological deficits. The detection rate seemed to be higher in patients with longer lasting symptoms, but the difference between patients with TIA (29%) and RIND (47%) was not significant. CONCLUSIONS: Diffusion weighted MRI is a sensitive indicator of acute ischaemic brainstem deficits even in patients with reversible neurological deficit. Early identification of patients with TIA and increased risk of stroke may influence acute management and improve patient outcome.


Asunto(s)
Tronco Encefálico/irrigación sanguínea , Tronco Encefálico/patología , Ataque Isquémico Transitorio/patología , Imagen por Resonancia Magnética , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Femenino , Humanos , Ataque Isquémico Transitorio/diagnóstico , Masculino , Persona de Mediana Edad , Examen Neurológico , Estudios Prospectivos , Factores de Riesgo , Sensibilidad y Especificidad , Accidente Cerebrovascular
12.
J Neurol ; 248(10): 850-5, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11697520

RESUMEN

BACKGROUND: An upper motor neuron (UMN) lesion in amyotrophic lateral sclerosis (ALS) is often difficult to identify because clinical signs may be discrete or masked by severe simultaneous LMN lesions. We compared the diagnostic sensitivity of transcranial magnetic stimulation (TMS) to cranial muscles and limb muscles in the detection of UMN lesions. DESIGN: We investigated corticobulbar and corticospinal tract function to the tongue/orofacial muscles and abductor digiti minimi/tibial anterior muscles with TMS in 51 patients with ALS to compare the diagnostic yield in the detection of UMN dysfunction. An UMN lesion was assumed when the following were found: the peripheral conduction time and amplitude of the M-wave were within the normal range, the response to cortical stimulation was absent, the TMS evoked/M-wave amplitude ratio was reduced, and the central motor conduction time or the interside difference was delayed (> mean+2.5 SD). RESULTS: On the basis of these criteria a UMN lesion to the orofacial muscles was identified in 24 patients (47%), to the tongue in 27 (53%), and to the upper and lower limbs in 13 (25%) and 22 patients (43%), respectively. Combined abnormalities from all sites increased the diagnostic yield to 39 patients (76%). TMS of the limb muscles confirmed a UMN lesion in only 15 (54%) of the 28 patients with clinically confirmed UMN involvement. This number increased to 23 patients (82%) if tongue and orofacial muscles were taken into acount. CONCLUSION: Our results indicate the early and in most cases subclinical corticobulbar tract involvement of the central motor pathways to the orofacial muscles and tongue in ALS. TMS of the tongue and orofacial muscles had a higher sensitivity in identifying UMN lesions than that of the upper and lower limbs.


Asunto(s)
Esclerosis Amiotrófica Lateral/fisiopatología , Campos Electromagnéticos , Tractos Piramidales/fisiopatología , Adulto , Anciano , Progresión de la Enfermedad , Extremidades/inervación , Extremidades/fisiología , Músculos Faciales/inervación , Músculos Faciales/fisiología , Nervio Facial/fisiopatología , Femenino , Humanos , Nervio Hipogloso/fisiopatología , Masculino , Persona de Mediana Edad , Fibras Nerviosas/fisiología , Estimulación Física , Tractos Piramidales/efectos de la radiación , Lengua/inervación , Lengua/fisiología
13.
Eur Neurol ; 46(4): 202-5, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11721127

RESUMEN

OBJECTIVES: Normative values of the masseter reflex are scarce. We studied the latencies, amplitudes and side differences of the masseter reflex in 105 healthy volunteers between the ages of 5 and 78 years. METHODS: Latencies were calculated as the mean of 10 single sweeps and, simultaneously, measured from the summation curve. Short-term reproducibility was determined in 33 volunteers by retesting the reflex after 1 week. RESULTS: There was a positive correlation between age and latencies and a negative correlation between age and amplitude. Maximal normal latencies were 8.3 ms for men and 7.9 ms for women in the age group below 50 years and 9.1 and 9.2 ms for the age group above 50 years. Latency differences between the right and left sides of >0.4 ms for subjects aged below 50 years and >0.5 ms for subjects aged above 50 years exceeded the 95% confidence interval. Amplitudes did not depend on gender. Calculated as a percentage of the side with higher amplitude, differences above one third could be accepted as abnormal. CONCLUSION: The masseter reflex appears to be a stable and robust clinical test, if age and gender differences are taken into account.


Asunto(s)
Envejecimiento/fisiología , Músculo Masetero/inervación , Reflejo/fisiología , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Masculino , Mesencéfalo/fisiología , Persona de Mediana Edad , Husos Musculares/fisiología , Puente/fisiología , Tiempo de Reacción/fisiología , Valores de Referencia , Nervio Trigémino/fisiología
14.
Comput Biol Med ; 31(6): 407-27, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11604148

RESUMEN

We present a hybrid system for automatic analysis of clinical routine EEG, comprising a spectral analysis and an expert system. EEG raw data are transformed into the time-frequency domain by the so-called adaptive frequency decomposition. The resulting frequency components are converted into pseudo-linguistic facts via fuzzification. Finally, an expert system applies symbolic rules formulated by the neurologist to evaluate the extracted EEG features. The system detects artefacts, describes alpha rhythm by frequency, amplitude, and stability and after artefact rejection detects pathologic slow activity. All results are displayed as linguistic terms, numerical values and maps of temporal extent, giving an overview about the clinical routine EEG.


Asunto(s)
Diagnóstico por Computador , Electroencefalografía/estadística & datos numéricos , Sistemas Especialistas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Ritmo alfa , Biometría , Encefalopatías/diagnóstico , Encefalopatías/fisiopatología , Ritmo Delta , Lógica Difusa , Humanos , Persona de Mediana Edad , Ritmo Teta
15.
Eur J Radiol ; 39(3): 180-5, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11566246

RESUMEN

BACKGROUND AND PURPOSE: diffusion weighted magnetic resonance imaging (MRI) is highly sensitive in detecting acute supratentorial cerebral ischemia and Diffusion Weighted Imaging (DWI) lesion size has been shown to correlate strongly with the neurologic deficit in middle cerebral artery territory stroke. However, data concerning infratentorial strokes are rare. We examined the size and evolution of acute brain stem ischemic lesions and their relationship to neurological outcome. METHODS: brain stem infarctions of 11 patients were analyzed. We performed DWI in all patients and in 7/11 patients within 24 h, T2W sequences within the first 2 weeks (10/11 patients) and follow-up MRI (MR2) within 3-9 months (median 4.8 months) later (12/12 patients). Lesion volumes were compared with early and follow-up neurologic deficit as determined by National Institutes of Health Stroke Scale (NIHSS) score. RESULTS: the relative infarct volumes--with MR2 lesion size set to 100%--decreased over the time (P<0.02) with a mean shrinking factor of 3.3 between DWI (MR0) and the follow-up MRT (P<0.02), and 1.6 between early T2W (MR1) and MR2 (P<0.04). The mean DWI volume size (MR0) was larger than the early T2W (P<0.02). Although neurological outcome was good in all patients (mean NIHSS score of 1.3 at follow-up), early NIHSS and follow-up NIHSS scores were strongly correlated (r=0.9, P<0.00). NIHSS score at follow-up was highly correlated with lesion size of DWI (MR0; r=0.71, P<0.04) and T2W of MR1 (r=0.86, P<0.001). CONCLUSIONS: in this study, we saw a shrinking of the brain stem infarct volume according to clinical improvement of patients. Great extension of restricted diffusion in the acute stage does not necessarily implicate a large resulting infarction or a bad clinical outcome.


Asunto(s)
Infartos del Tronco Encefálico/diagnóstico , Imagen por Resonancia Magnética , Accidente Cerebrovascular/diagnóstico , Imagen Eco-Planar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Factores de Tiempo
16.
BMC Neurol ; 1: 4, 2001 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-11570979

RESUMEN

BACKGROUND: The existence of a prenuclear abduction paresis is still debated. METHODS: In a retrospective design, we identified 22 patients with isolated unilateral (n = 20) or bilateral (n = 2) abduction paresis and electrophysiologic abnormalities indicating rostral pontine and/or mesencephalic lesions. Another 11 patients had unilateral abduction paresis with additional ocular motor abnormalities indicating midbrain dysfunction. Eight of these 11 patients also had electrophysiological abnormalities supporting this location. Electrophysiological examinations in all patients included masseter and blink reflexes (MassR, BlinkR), brainstem auditory evoked potentials (BAEP), and direct current elctro-oculography (EOG). RESULTS: Unilateral MassR abnormalities in patients with unilateral abduction paresis were seen in 17 patients and were almost always (in 16 of 17 patients) on the side of the abduction paresis. Another 11 patients had bilateral MassR abnormalities. BlinkR was always normal. EOG disclosed slowed abduction saccades in the non-paretic eye in 6 patients and slowed saccades to the side opposite to the abduction paresis in another 5 patients. Re-examinations were done in 27 patients showing normalization or improvement of masseter reflex abnormalities in 18 of 20 patients and in all patients with EOG abnormalities. This was always associated with clinical improvement. CONCLUSIONS: Electrophysiologically documented or clinically evident rostral pontine and/or mesencephalic lesions in our patients exclude an infranuclear intrapontine 6th nerve lesion and indicate the existence of an abduction paresis of prenuclear origin. An increased tone of the antagonistic medial rectus muscle during lateral gaze either by abnormal convergence or impaired medial rectus inhibition seems most likely.


Asunto(s)
Enfermedades del Nervio Abducens/diagnóstico , Mesencéfalo/fisiopatología , Trastornos de la Motilidad Ocular/diagnóstico , Paresia/diagnóstico , Puente/fisiopatología , Enfermedades del Nervio Abducens/etiología , Enfermedades del Nervio Abducens/fisiopatología , Parpadeo , Infartos del Tronco Encefálico/complicaciones , Infartos del Tronco Encefálico/diagnóstico , Diagnóstico Diferencial , Electrodiagnóstico , Electrooculografía , Potenciales Evocados Auditivos del Tronco Encefálico , Humanos , Imagen por Resonancia Magnética , Músculo Masetero/fisiopatología , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/diagnóstico , Trastornos de la Motilidad Ocular/fisiopatología , Paresia/etiología , Tiempo de Reacción , Estudios Retrospectivos , Movimientos Sacádicos
17.
Muscle Nerve ; 24(10): 1327-31, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11562912

RESUMEN

The aim of the study was to investigate the relation of the blink reflex R1 arc to known anatomical brainstem structures. Acute vascular brainstem lesions as identified by magnetic resonance imaging (MRI) of patients with isolated R1 pathology were superimposed into a stereotactic anatomical atlas using a new method of digital postprocessing. Isolated acute brainstem lesions were documented by diffusion-weighted MRI in 12 of 24 patients with unilateral R1 pathology. The lesions were located in the ipsilateral mid- to lower pons. In three patients only, the lesion had partial contact with the principal sensory nucleus of the trigeminal nerve (PSN) on at least one level. In two patients, the lesion involved the medial longitudinal fasciculus. Most lesions were located medially and ventrally to the PSN on transverse slices. Our results underline the high localizing value of changes in the R1 component of the blink reflex in patients with ipsilateral pontine functional deficits. Although available physiological evidence suggests that the R1 component of the blink reflex traverses an oligosynaptic pathway, this MRI study does not support the view that synaptic transmission in the PSN subserves R1. The reflex arc probably descends more medially and ventrally on its course to the facial nucleus.


Asunto(s)
Parpadeo , Infartos del Tronco Encefálico/patología , Tronco Encefálico/patología , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Anciano de 80 o más Años , Tronco Encefálico/fisiopatología , Infartos del Tronco Encefálico/fisiopatología , Estimulación Eléctrica , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Persona de Mediana Edad
18.
Eur J Neurol ; 8(5): 489-93, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11554915

RESUMEN

We investigated the reliability of a new digital post-processing magnetic resonance imaging (MRI) technique in ischemic brain stem lesions to identify relations of the lesion to anatomical brain stem structures. The target was a medial longitudinal fasciculus (MLF) lesion, which was evident from ipsilateral internuclear ophthalmoplegia (INO). Sixteen patients with acute unilateral INO and an isolated acute brain stem lesion in T2- and EPI-diffusion weighted MRI within 2 days after the onset of symptoms were studied. The MRI slice direction was parallel and perpendicular to a slice selection of a stereotactic anatomical atlas. The individual slices were normalized and projected in the digitalized atlas. The eye movement disorder was monitored by electro-oculography. In all patients with clinical or subclinical electro-oculographically documented INO and MRI proven brain stem infarction the lesion covered or at least partially overlapped the ipsilateral MLF at one or more atlas levels. We conclude that digital post-processing MRI with normalizing and projecting brain stem lesions in an anatomical atlas is a reliable method to demonstrate the anatomical structures involved by the lesion. Combined with electrophysiological brain stem testing, this method may be a useful tool to identify incompletely understood pathways mediating brain stem reflexes or the generators of evoked potentials.


Asunto(s)
Tronco Encefálico/patología , Tronco Encefálico/fisiopatología , Oftalmoplejía/patología , Oftalmoplejía/fisiopatología , Adulto , Anciano , Mapeo Encefálico , Electrooculografía , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
19.
Brain ; 124(Pt 9): 1866-76, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11522588

RESUMEN

Transcranial magnetic stimulation was used to investigate the corticofacial projections in 53 patients with (n = 28) and without (n = 25) central facial paresis due to unifocal ischaemic lesions at different brainstem levels. Lesion topography documented by MRI studies was correlated with the electrophysiological findings. In the majority of patients the corticofacial fibres travel within the ventromedial base of the pons and cross the midline at the level of the facial nucleus. In some individuals, however, we found evidence that corticolingual fibres form an 'aberrant bundle' in a paralemniscal position at the dorsal edge of the pontine base. In other patients the corticofacial fibres loop down into the ventral part of the upper medulla, cross the midline and ascend in the dorsolateral medullary region ipsilaterally to the facial nucleus. The findings suggest that facial paresis due to a brainstem lesion may present as contralateral supranuclear facial paresis by a lesion of the cerebral peduncle, pontine base, the aberrant bundle and the ventral medulla. Supranuclear facial paresis ipsilateral to the lesion side may result from a lesion in the lateral medulla, and facial paresis of the supranuclear type may be imitated by a lesion of the peripheral facial nerve in the dorsolateral medulla with involvement of the lower pons.


Asunto(s)
Tronco Encefálico/citología , Corteza Cerebral/citología , Nervio Facial/citología , Tractos Piramidales/citología , Tronco Encefálico/fisiología , Corteza Cerebral/fisiología , Estimulación Eléctrica , Nervio Facial/fisiología , Humanos , Imagen por Resonancia Magnética , Magnetismo , Tractos Piramidales/fisiología
20.
J Neurol Sci ; 186(1-2): 59-63, 2001 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-11412873

RESUMEN

Isolated cranial nerve involvement in primary Sjögren's syndrome (primary SS) has rarely been described. We report the case of a patient with sensory neuropathy of the trigeminal and also the glossopharyngeal and vagal nerves, which has not been identified previously. The electrophysiological findings in our patient with primary SS confirmed trigeminal sensory neuropathy with abnormal blink reflexes and abnormal cutaneous masseter inhibitory reflexes.


Asunto(s)
Enfermedades de los Nervios Craneales/diagnóstico , Enfermedades de los Nervios Craneales/fisiopatología , Síndrome de Sjögren/diagnóstico , Síndrome de Sjögren/fisiopatología , Enfermedades de los Nervios Craneales/etiología , Electrofisiología , Femenino , Enfermedades del Nervio Glosofaríngeo/diagnóstico , Enfermedades del Nervio Glosofaríngeo/etiología , Enfermedades del Nervio Glosofaríngeo/fisiopatología , Humanos , Persona de Mediana Edad , Síndrome de Sjögren/complicaciones , Enfermedades del Nervio Trigémino/diagnóstico , Enfermedades del Nervio Trigémino/etiología , Enfermedades del Nervio Trigémino/fisiopatología , Enfermedades del Nervio Vago/diagnóstico , Enfermedades del Nervio Vago/etiología , Enfermedades del Nervio Vago/fisiopatología
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