A 3D Computational Head Model Under Dynamic Head Rotation and Head Extension Validated Using Live Human Brain Data, Including the Falx and the Tentorium.

We employ an advanced 3D computational model of the head with high anatomical fidelity, together with measured tissue properties, to assess the consequences of dynamic loading to the head in two distinct modes: head rotation and head extension. We use a subject-specific computational head model, using the material point method, built from T1 magnetic resonance images, and considering the anisotropic properties of the white matter which can predict strains in the brain under large rotational accelerations. The material model now includes the shear anisotropy of the white matter. We validate the model under head rotation and head extension motions using live human data, and advance a prior version of the model to include biofidelic falx and tentorium. We then examine the consequences of incorporating the falx and tentorium in terms of the predictions from the computational head model.

Rapid, high-resolution, whole-brain, susceptibility-based MRI of multiple sclerosis.

BACKGROUND: Susceptibility-based MRI offers a unique opportunity to study neurological diseases such as multiple sclerosis (MS). In this work, we assessed a three-dimensional segmented echo-planar-imaging (3D-EPI) sequence to rapidly acquire high-resolution T2 -weighted and phase contrast images of the whole brain. We also assessed if these images could depict important features of MS at clinical field strength, and we tested the effect of a gadolinium-based contrast agent (GBCA) on these images. MATERIALS AND METHODS: The 3D-EPI acquisition was performed on four healthy volunteers and 15 MS cases on a 3T scanner. The 3D sagittal images of the whole brain were acquired with a voxel size of 0.55 × 0.55 × 0.55 mm(3) in less than 4 minutes. For the MS cases, the 3D-EPI acquisition was performed before, during, and after intravenous GBCA injection. RESULTS: Both T2-weighted and phase-contrast images from the 3D-EPI acquisition were sensitive to the presence of lesions, parenchymal veins, and tissue iron. Conspicuity of the veins was enhanced when images were obtained during injection of GBCA. CONCLUSIONS: We propose this rapid imaging sequence for investigating, in a clinical setting, the spatiotemporal relationship between small parenchymal veins, iron deposition, and lesions in MS patient brains.

Intracranial arteries in individuals with the elastin gene hemideletion of Williams syndrome.

BACKGROUND AND PURPOSE: Williams syndrome, a rare genetic disorder with a striking neurobehavioral profile characterized by extreme sociability and impaired visuospatial construction abilities, is caused by a hemideletion that includes the elastin gene, resulting in frequent supravavular aortic stenosis and other stenotic arterial lesions. Strokes have been reported in Williams syndrome. Although the extracranial carotid artery has been studied in a sample of patients with Williams syndrome, proximal intracranial arteries have not. MATERIALS AND METHODS: Using MRA, we studied the intracranial vessels in 27 participants: 14 patients with Williams syndrome (age range, 18-44 years; mean age, 27.3 ± 9.1; 43% women) and 13 healthy control participants with similar age and sex distribution (age range, 22-52 years; mean age, 33.4 ± 7.6; 46% women). All participants with Williams syndrome had hemideletions of the elastin gene. Blinded to group allocation or to any other clinical data, a neuroradiologist determined the presence of intracranial vascular changes in the 2 groups. RESULTS: The Williams syndrome group and the healthy control group had similar patency of the proximal intracranial arteries, including the internal carotid and vertebral arteries; basilar artery; and stem and proximal branches of the anterior cerebral artery, MCA, and posterior cerebral arteries. The postcommunicating segment of the anterior cerebral artery was longer in the Williams syndrome group. CONCLUSIONS: Despite the elastin haploinsufficiency, the proximal intracranial arteries in Williams syndrome preserve normal patency.

Decreased GABA-A binding on FMZ-PET in succinic semialdehyde dehydrogenase deficiency.

OBJECTIVE: Succinic semialdehyde dehydrogenase (SSADH) deficiency is an autosomal recessive disorder of GABA metabolism characterized by elevated levels of GABA and gamma-hydroxybutyric acid. Clinical findings include intellectual impairment, hypotonia, hyporeflexia, hallucinations, autistic behaviors, and seizures. Autoradiographic labeling and slice electrophysiology studies in the murine model demonstrate use-dependent downregulation of GABA(A) receptors. We studied GABA(A) receptor activity in human SSADH deficiency utilizing [(11)C]-flumazenil (FMZ)-PET. METHODS: FMZ binding was measured in 7 patients, 10 unaffected parents, and 8 healthy controls. Data analysis was performed using a reference region compartmental model, with time-activity curve from pons as the input function. Relative parametric binding potential (BP(ND)) was derived, with MRI-based pixel by pixel partial volume correction, in regions of interest drawn on coregistered MRI. RESULTS: In amygdala, hippocampus, cerebellar vermis, frontal, parietal, and occipital cortex, patients with SSADH deficiency had significant reductions in FMZ BP(ND) compared to parents and controls. Mean cortical values were 6.96 +/- 0.79 (controls), 6.89 +/- 0.71 (parents), and 4.88 +/- 0.77 (patients) (F ratio 16.1; p < 0.001). There were no differences between controls and parents in any cortical region. CONCLUSIONS: Succinic semialdehyde dehydrogenase (SSADH) deficient patients show widespread reduction in BZPR binding on [(11)C]-flumazenil-PET. Our results suggest that high endogenous brain GABA levels in SSADH deficiency downregulate GABA(A)-BZPR binding site availability. This finding suggests a potential mechanism for neurologic dysfunction in a serious neurodevelopmental disorder, and suggests that PET may be useful to translate studies in animal models to human disease.

Segregation of enlarged vestibular aqueducts in families with non-diagnostic SLC26A4 genotypes.

BACKGROUND: Hearing loss with enlarged vestibular aqueduct (EVA) can be inherited as an autosomal recessive trait caused by bi-allelic mutations of SLC26A4. However, many EVA patients have non-diagnostic SLC26A4 genotypes with only one or no detectable mutant alleles. METHODS AND RESULTS: In this study, the authors were unable to detect occult SLC26A4 mutations in EVA patients with non-diagnostic genotypes by custom comparative genomic hybridisation (CGH) microarray analysis or by sequence analysis of conserved non-coding regions. The authors sought to compare the segregation of EVA among 71 families with two (M2), one (M1) or no (M0) detectable mutant alleles of SLC26A4. The segregation ratios of EVA in the M1 and M2 groups were similar, but the segregation ratio for M1 was significantly higher than in the M0 group. Haplotype analyses of SLC26A4-linked STR markers in M0 and M1 families revealed discordant segregation of EVA with these markers in eight of 24 M0 families. CONCLUSION: The results support the hypothesis of a second, undetected SLC26A4 mutation that accounts for EVA in the M1 patients, in contrast to non-genetic factors, complex inheritance, or aetiologic heterogeneity in the M0 group of patients. These results will be helpful for counselling EVA families with non-diagnostic SLC26A4 genotypes.

Gradient echo MRI: implementation of a training tutorial for intracranial hemorrhage diagnosis.

BACKGROUND: Recent studies have demonstrated that gradient echo (GRE) MRI sequences are as accurate as CT for the detection of intracerebral hemorrhage (ICH) in the context of acute stroke. However, many physicians who currently read acute stroke imaging studies may be unfamiliar with interpretation of GRE images. METHODS: An NIH Web-based training program was developed including a pretest, tutorial, and posttest. Physicians involved in the care of acute stroke patients were encouraged to participate. The tutorial covered acute, chronic, and mimic hemorrhages as they appear on CT, diffusion-weighted imaging, and GRE sequences. Ability of users to identify ICH presence, type, and age on GRE was compared from the pretest to posttest timepoint. RESULTS: A total of 104 users completed the tutorial. Specialties represented included general radiology (42%), general neurology (16%), neuroradiology (15%), stroke neurology (14%), emergency medicine (1%), and other (12%). Median overall score improved pretest to posttest from 66.7% to 83.3%, p < 0.001. Improvement by category was as follows: acute ICH, 66.7%-100%, p < 0.001; chronic ICH, 33.3%-66.7%, p < 0.001; ICH negatives/mimics, 100%-100%, p = 0.787. Sensitivity for identification of acute hemorrhage improved from 68.2% to 96.4%. CONCLUSIONS: Physicians involved in acute stroke care achieved significant improvement in gradient echo (GRE) hemorrhage interpretation after completing the NIH GRE MRI tutorial. This indicates that a Web-based tutorial may be a viable option for the widespread education of physicians to achieve an acceptable level of diagnostic accuracy at reading GRE MRI, thus enabling confident acute stroke treatment decisions.

Altered language processing in autosomal dominant partial epilepsy with auditory features.

BACKGROUND: Autosomal dominant partial epilepsy with auditory features (ADPEAF) is an idiopathic focal epilepsy syndrome with auditory symptoms or receptive aphasia as major ictal manifestations, frequently associated with mutations in the leucine-rich, glioma inactivated 1 (LGI1) gene. Although affected subjects do not have structural abnormalities detected on routine MRI, a lateral temporal malformation was identified through high resolution MRI in one family. We attempted to replicate this finding and to assess auditory and language processing in ADPEAF using fMRI and magnetoencephalography (MEG). METHODS: We studied 17 subjects (10 affected mutation carriers, 3 unaffected carriers, 4 noncarriers) in 7 ADPEAF families, each of which had a different LGI1 mutation. Subjects underwent high-resolution structural MRI, fMRI with an auditory description decision task (ADDT) and a tone discrimination task, and MEG. A control group comprising 26 volunteers was also included. RESULTS: We found no evidence of structural abnormalities in any of the 17 subjects. On fMRI with ADDT, subjects with epilepsy had significantly less activation than controls. On MEG with auditory stimuli, peak 2 auditory evoked field latency was significantly delayed in affected individuals compared to controls. CONCLUSIONS: These findings do not support the previous report of a lateral temporal malformation in autosomal dominant partial epilepsy with auditory features (ADPEAF). However, our fMRI and magnetoencephalography data suggest that individuals with ADPEAF have functional impairment in language processing.

Behavioral flexibility impairment with negative feedback in refractory temporal lobe epileptic patients with unilateral amygdala and hippocampal resection.

INTRODUCTION: Patients with amygdala dysfunction generally have behavioral impairment. Temporal lobe surgery might be a model of study of unilateral amygdala resection. The objective of this study was to evaluate behavioral flexibility in epileptic patients who undergo amygdala resection for epilepsy surgery and evaluate its relationship with their neuropsychiatric symptoms. MATERIAL AND METHODS: Ten epileptic patients who underwent amygdala and hippocampal resection (6 left and 4 right) matched by age and educational level with 10 healthy controls were tested with an extensive neuropsychological and neuropsychiatric battery. Psychiatric symptomatology was measured with the positive and negative syndrome scale (PANSS) and the Beck depression inventory. To assess behavioral flexibility the emotion-related visual reversal-learning task (O'Doherty et al., 2001) and the gambling task (Bechara et al., 1994) were used. RESULTS: Patient's mean scores were: Beck: 8 +/- 1.5; PANSS positive: 10 +/- 1.3, and negative: 14.4 +/- 2.2; intellectual quotient (IQ): 101.4 +/- 6.3; category number in Wisconsin card sorting test: 4.6 +/- 2.4. The emotion-related visual reversal-learning task showed significance differences in the number of reversion: healthy controls: 9.3; epileptic patients: 4.23 (p < 0.001); in the number of trials to the first reversion: healthy controls: 5; epileptic patients: 23.42 (p < 0.05). There was no correlation between reversion and depression, PANSS and IQ. CONCLUSIONS: Patients with epilepsy who undergo unilateral hippocampal and amygdala resection appear to have alterations in the reversion capacity with an emotional component that would explain the lack of behavior flexibility that they sometimes have and that are not related with either the isolated presence of executive alterations or low intellectual quotient.

Flexibilidad conductual ante un feedback negativo en pacientes epilépticos temporales refractarios con resección amigdalohipocámpica unilateral / Behavioral flexibility impairment with negative feedback in refractory temporal lobe epileptic patients with unilateral amygdala and hippocampal resection

Introducción. Los pacientes con disfunciones amigdalinas suelen presentar alteraciones en su conducta. La cirugía de epilepsia temporal proporciona un modelo de estudio de la resección amigdalina unilateral. El objetivo de este trabajo fue estudiar la flexibilidad conductual ante un feedback afectivo negativo en pacientes con resección de amígdala por cirugía de epilepsia y evaluar su relación con los síntomas neuropsiquiátricos. Material y métodos. Diez pacientes con epilepsia del lóbulo temporal (ELT) con resección de amígdala e hipocampo, 6 derechas y 4 izquierdas, apareados por edad y nivel de educación con 10 sujetos controles normales, fueron evaluados con una extensa batería neuropsicológica y neuropsiquiátrica que incluyó la Escala de síndromes positivos y negativos (PANSS) y la Escala de depresión de Beck. Para estudiar la adaptabilidad conductual se utilizaron el Test de Aprendizaje y reversión afectiva (O'Doherty et al., 2001) y el Test del Casino (Bechara et al., 1994). Resultados. Los pacientes tenían los siguientes puntajes (en media ± DE): escala de Beck de 8 ± 1,5, PANSS positiva de 10 ± 1,3 y negativa de 14,4 ± 2,2, un cociente intelectual (CI) de 101,4 ± 6,3, las categorías completadas en el Test de las cartas de Wisconsin fueron de 4,6 ± 2,4. En el test de aprendizaje y reversión afectiva mostraron diferencias significativas en el número de reversiones: controles, 9,3; ELT, 4,23 (p < 0,001), y en los ensayos para lograr la primera reversión: controles, 5; ELT, 23,42 (p < 0,05). No hubo correlación significativa entre las variables de reversión, depresión, la puntuación de la PANSS o el CI. Conclusiones. Los pacientes epilépticos con resección amigdalohipocámpica unilateral tendrían alteraciones en la capacidad de reversión con componente afectivo que explicarían la falta de flexibilidad conductual que a veces presentan los mismos y que no se relacionan ni con la presencia aislada de alteraciones ejecutivas ni con un bajo cociente intelectual

Introduction. Patients with amygdala dysfunction generally have behavioral impairment. Temporal lobe surgery might be a model of study of unilateral amygdala resection. The objective of this study was to evaluate behavioral flexibility in epileptic patients who undergo amygdala resection for epilepsy surgery and evaluate its relationship with their neuropsychiatric symptoms. Material and methods. Ten epileptic patients who underwent amygdala and hippocampal resection (6 left and 4 right) matched by age and educational level with 10 healthy controls were tested with an extensive neuropsychological and neuropsychiatric battery. Psychiatric symptomatology was measured with the positive and negative syndrome scale (PANSS) and the Beck depression inventory. To assess behavioral flexibility the emotion-related visual reversal-learning task (O'Doherty et al., 2001) and the gambling task (Bechara et al., 1994) were used. Results. Patient's mean scores were: Beck: 8 ± 1.5; PANSS positive: 10 ± 1.3, and negative: 14.4 ± 2.2; intellectual quotient (IQ): 101.4 ± 6.3; category number in Wisconsin card sorting test: 4.6 ± 2.4. The emotion-related visual reversal-learning task showed significance differences in the number of reversion: healthy controls: 9.3; epileptic patients: 4.23 (p < 0.001); in the number of trials to the first reversion: healthy controls: 5; epileptic patients: 23.42 (p < 0.05). There was no correlation between reversion and depression, PANSS and IQ. Conclusions. Patients with epilepsy who undergo unilateral hippocampal and amygdala resection appear to have alterations in the reversion capacity with an emotional component that would explain the lack of behavior flexibility that they sometimes have and that are not related with either the isolated presence of executive alterations or low intellectual quotient

Decreased thickness of primary motor cortex in primary lateral sclerosis.

BACKGROUND AND PURPOSE: Primary lateral sclerosis (PLS) is a rare form of motor neuron disease characterized by upper motor neuron dysfunction. Because pathologic examination has revealed a loss of neurons in the motor cortex of patients with PLS, we sought to confirm and extend this finding by using MR imaging to measure cortical thickness. METHODS: Seven patients with PLS and 7 age-matched neurologically normal control subjects were examined with heavily T1-weighted short-tau inversion recovery (STIR) MR imaging performed at 3T. Cortical thickness in the anterior and posterior banks of both the central and precentral sulci were measured. RESULTS: Primary motor cortex (M1) was significantly thinner in patients with PLS than M1 in healthy control subjects, measuring 2.32 +/- 0.21 mm compared with 2.79 +/- 0.18 mm (P = .0008). Cortical thickness did not differ between the 2 groups for primary sensory cortex or for the anterior or posterior banks of the precentral sulcus. Therefore, loss of gray matter was specific to motor cortex. Although this difference was modest, cortical thickness discriminated between the 2 groups; only 1 PLS case was within the range of normal measurements. CONCLUSION: Decreased thickness of M1 on the anterior bank of the precentral sulcus in patients with PLS, demonstrable by MR imaging, indicates a selective loss of upper motor neurons in this disease. Measurements of cortical thickness by MR imaging may provide a useful biomarker for diagnosis and study of upper motor neuron diseases.

Image-guided, direct convective delivery of glucocerebrosidase for neuronopathic Gaucher disease.

OBJECTIVE: To determine if convection-enhanced delivery (CED) of glucocerebrosidase could be used to treat targeted sites of disease progression in the brain and brainstem of a patient with neuronopathic Gaucher disease while monitoring enzyme distribution using MRI. METHODS: A CED paradigm in rodents (n = 8) and primates (n = 5) that employs co-infusion of a surrogate MRI tracer (gadolinium diethylenetriamine penta-acetic acid [Gd-DTPA]) with glucocerebrosidase to permit real-time monitoring of distribution was developed. The safety and feasibility of this delivery and monitoring paradigm were evaluated in a patient with type 2 Gaucher disease. RESULTS: Animal studies revealed that real-time, T1-weighted, MRI of Gd-DTPA accurately tracked enzyme distribution during CED. Targeted perfusion of clinically affected anatomic sites in a patient with neuronopathic Gaucher disease (frontal lobe and brainstem) with glucocerebrosidase was successfully performed. Real-time MRI revealed progressive and complete filling of the targeted region with enzyme and Gd-DTPA infusate. The patient tolerated the infusions without evidence of toxicity. CONCLUSIONS: Convection-enhanced delivery can be used to safely perfuse large regions of the brain and brainstem with therapeutic levels of glucocerebrosidase. Co-infused imaging surrogate tracers can be used to monitor and control the distribution of therapeutic agents in vivo. Patients with neuronopathic Gaucher disease and other intrinsic CNS disorders may benefit from a similar treatment paradigm.

In vivo detection of cortical plaques by MR imaging in patients with multiple sclerosis.

BACKGROUND AND PURPOSE: In vivo detection of cortical lesions in patients with multiple sclerosis (MS) by MR imaging is hampered by several factors. Among them is the low contrast between small cortical lesions and surrounding cortical gray matter offered by present techniques. METHODS: T1-weighted 3D spoiled gradient-recalled-echo (SPGR) volumes and 2D fluid-attenuated inversion recovery (FLAIR) sequences of 22 patients with MS who had 12 monthly brain MR imaging examinations at 1.5T, using a quadrature head coil, were retrospectively analyzed. These serial studies were coregistered and averaged to generate a single high signal-to-noise ratio (SNR) mean image, which was used to identify cortical lesions. The means of 12 FLAIRs and SPGRs from 14 age- and sex-matched healthy volunteers were analyzed as well. RESULTS: No cortical lesions were found on images of healthy subjects. Eighty-six cortical lesions were identified in 13 (59.1%) patients, predominantly in the frontal lobe (73.3%); 23.3% of cortical lesions lay entirely in the cortex, whereas the remaining lesions invaded the white matter underneath. CONCLUSION: Averaging multiple SPGRs created a single high SNR volume, allowing identification of cortical lesions. Because data were obtained monthly for 1 year, the average image does not account for transient lesion activity. However, for cortical lesions that remained stable during this time, the findings are valid in demonstrating the importance of high SNR images for detecting cortical brain abnormalities in MS.

Treatment of neurocysticercosis: current status and future research needs.

Here we put forward a roadmap that summarizes important questions that need to be answered to determine more effective and safer treatments. A key concept in management of neurocysticercosis is the understanding that infection and disease due to neurocysticercosis are variable and thus different clinical approaches and treatments are required. Despite recent advances, treatments remain either suboptimal or based on poorly controlled or anecdotal experience. A better understanding of basic pathophysiologic mechanisms including parasite survival and evolution, nature of the inflammatory response, and the genesis of seizures, epilepsy, and mechanisms of anthelmintic action should lead to improved therapies.

Differential cortical thickness across the central sulcus: a method for identifying the central sulcus in the presence of mass effect and vasogenic edema.

BACKGROUND AND PURPOSE: Identification of the motor strip on MR imaging studies is difficult in the presence of mass effect and vasogenic edema because sulcal landmarks are obscured. We hypothesize that a difference in cortical thickness between the motor and sensory strips is readily apparent on T2-weighted images in the presence of vasogenic edema and reliably identifies the central sulcus. METHODS: Thirteen patients with brain tumors resulting in vasogenic edema near the central sulcus were identified. The cortical thickness of the anterior and posterior banks of the central sulcus as well as the neighboring sulci in the frontal and parietal lobes were measured from T2-weighted images. Similar measures were obtained from neighboring sulci in the frontal and parietal lobes. Location of the central sulcus was confirmed with standard anatomic landmarks in all patients and by intraoperative cortical mapping in 2 patients. RESULTS: A twofold difference in cortical thickness between the anterior and posterior banks of the central sulcus uniquely identified the central sulcus on T2-weighted images in the presence of vasogenic edema, despite the marked distortion of sulcal anatomy as a result of mass effect. This relationship was not present in neighboring sulci. CONCLUSION: Cytoarchitectonic differences in the motor and sensory cortices result in a markedly thicker posterior than anterior bank of the central sulcus that is readily visible on routine T2-weighted images in the presence of vasogenic edema. Therefore, the cortical thickness can serve as a complementary method in identification of the motor strip in patients with mass effect.

Calcific neurocysticercosis and epileptogenesis.

Neurocysticercosis is responsible for increased rates of seizures and epilepsy in endemic regions. The most common form of the disease, chronic calcific neurocysticercosis, is the end result of the host's inflammatory response to the larval cysticercus of Taenia solium. There is increasing evidence indicating that calcific cysticercosis is not clinically inactive but a cause of seizures or focal symptoms in this population. Perilesional edema is at times also present around implicated calcified foci. A better understanding of the natural history, frequency, epidemiology, and pathophysiology of calcific cysticercosis and associated disease manifestations is needed to define its importance, treatment, and prevention.

[Screening for mild cognitive impairment: usefulness of the 7-Minute Screen Test]. / Detección de deterioro cognitivo leve en asistencia primaria. Utilidad del Test de los Siete Minutos.

INTRODUCTION: The <<7- Minute Screen>> is a neurocognitive screening test for the detection of Alzheimer's disease (AD) patients in primary care settings. It consists of 4 brief subtests (orientation, memory, visuoconstruction and verbal fluency) and provides a broader neuropsychological profile than other widely used screening tests, The aim of the present study was to study the usefulness of this screening test for the detection of Mild Cognitive Impairment (MCI). METHODS: Thirty-two patients with probable AD (NINCDS-ADRDA criteria), 25 patients with MCI, and 35 healthy control subjects, matched for age and education, underwent a comprehensive neuropsychological battery and the Rio-de-la-Plata version of the 7-Minute Screen. RESULTS. This test showed 93 % sensitivity and 97% specificity in detecting mild-moderate Alzheimer's disease MMSE<24), but it exhibited a substantially decreased sensitivity (28 %) in its ability to detect MCI in AD (MMSE >2 4 ). CONCLUSION: The screening batteries do not replace a m o re compre h e n s i ve neuro psychological assessment. Th ey are useful in detecting patients with mild dementia, but caution must be the rule when considering a diagnosis of MCI.

Detección de deterioro cognitivo leve en asistencia primaria. Utilidad del Test de los Siete Minutos / Screening for mild cognitive impairment: usefulness of the 7-Minute Screen test

Introducción. El Test de los Siete Minutos fue desarrollado como un instrumento para emplearse en un consultorio de atención primaria para la detección de pacientes con enfermedad de Alzheimer. Los subtests que lo componen (orientación, memoria, visuoconstrucción y fluencia verbal) brindan un perfil neuropsicológico más amplio que el habitual en este tipo de baterías. El objetivo del presente estudio es evaluar su posible aplicación como instrumento de detección de deterioro cognitivo leve (DCL).Métodos. Fueron estudiados 32 sujetos con enfermedad de Alzheimer probable (criterios de NINCDS-ADRDA), 25 sujetos con DCL y 35 sujetos control apareados por edad y años de educación. A cada uno se le administró una extensa batería neuropsicológica. Se utilizó la traducción y adaptación del protocolo original para su uso en nuestro medio. Resultados. La sensibilidad del test fue del 93 por ciento y la especificidad del 97 por ciento para diagnóstico de enfermedad de Alzheimer leve-moderada (MMSE 24) y a sólo el 28 por ciento en DCL. Conclusión. Las baterías de detección no reemplazan a las de diagnóstico, pero son de utilidad para sospechar la presencia de una demencia e iniciar el estudio sistematizado del paciente de riesgo, aunque en el caso de DCL se debe dar mayor importancia a los tests de memoria. (AU)

Primary lateral sclerosis: A heterogeneous disorder composed of different subtypes?

OBJECTIVE: To determine identifiable subgroups of patients with primary lateral sclerosis (PLS) with distinct clinical features as a first step in identifying patients likely to have the same disorder. METHODS: Twenty-five patients meeting previously proposed diagnostic criteria for PLS were seen for examination, measurement of gait and finger tapping speed, and physiologic tests to assess motor pathways. Motor cortex excitability and central motor conduction time were assessed with transcranial magnetic stimulation. Brainstem motor pathways were assessed by the acoustic startle reflex. MRS was performed in a subgroup of patients to assess metabolites in the motor cortex. RESULTS: Fifty-six percent of the patients with PLS had a similar pattern of symptom progression, which the authors termed ascending. In these patients spasticity began in the legs and progressed slowly and steadily. Spasticity in the arms developed 3.6 years after the legs, on average, and speech impairment followed 1.5 years later. Motor evoked potentials were absent. MRS showed a mean reduction of N-acetylaspartate/creatinine in the motor cortex. The remaining patients with PLS had heterogeneous patterns of symptom progression and physiology. CONCLUSIONS: Patients with PLS with an ascending progression of symptoms form a distinct clinical subgroup that may be amenable to investigations of etiology and treatment.

Versión abreviada en español del test de denominación de Boston:su utilidad en el diagnóstico diferencial de la enfermedad de Alzheimer / A shortened form of the Spanish Boston naming test: a useful tool for the diagnosis of Alzheimer´s disease

Introducción. El test de denominación de Boston (TDB) es una de las pruebas más frecuentemente utilizadas para evaluar la denominación en pacientes con enfermedad de Alzheimer. Debido a su longitud, se han desarrollado varias formas abreviadas de esta prueba. Objetivo. El propósito de este estudio fue crear una versión abreviada del TDB en español que permita detectar los cambios semánticos precoces en la enfermedad de Alzheimer. Pacientes y métodos. Se han estudiado 103 pacientes con enfermedad de Alzheimer probable (criterios NINCDS-ADRDA), con GDS< 5, y 143 sujetos sanos, apareados por edad y escolaridad. Fueron excluidos aquellos sujetos con antecedentes de alcoholismo, otras enfermedades neurológicas o psiquiátricas previas y con educación <4 años. Pacientes y controles fueron evaluados con una batería neuropsicológica completa, que incluyó la versión de 60 láminas del TDB en español (adaptación Buenos Aires). Se calculó la sensibilidad y especificidad de cada lámina y su variabilidad con los datos demográficos. Se seleccionaron las 12 láminas más sensibles y específicas, y con menor variabilidad respecto a edad y escolaridad. Para el análisis estadístico se utilizó el análisis de varianza (ANOVA) y el coeficiente de correlación de Spearman. Resultados. La media del desempeño de los controles en la versión de 12 ítems fue de 11 puntos, con un desvío estándar de 1,16. No se observó correlación con edad (r= 0,14574) ni con el nivel educacional (r= 0,101293). La sensibilidad y especificidad para el diagnóstico de EA fue del 85 y 94 por ciento, respectivamente, similar a los valores de la versión original. Conclusión. Esta versión reducida de 12 ítems del TDB en español constituye una herramienta neuropsicológica útil para la detección de la EA, ya que conserva la capacidad discriminativa de la versión original, y no presenta influencia demográfica (AU)