RESUMEN
BACKGROUND: Presently, the unambiguous diagnosis of benign paroxysmal positioning vertigo (BPPV) requires the detection of positioning or positional nystagmus provoked by Dix-Hallpike (for vertical semicircular canals) or supine roll (for horizontal semicircular canals) manoeuvres, which indicates canalo- or cupolithiasis of affected semicircular canals. There are patients, however, in whom--despite typical complaints of BPPV--no positional nystagmus can be documented; this is called 'subjective BPPV' (sBPPV). These patients usually complain of short vertigo spells during and after sitting up, sometimes with abnormal retropulsion of the trunk. AIM: In this study, the authors aimed to ascertain whether these patients in fact demonstrate abnormal sitting-up trunk oscillations when measured by posturography. Of 200 unselected patients with vertigo or dizziness, 43% had sBPPV with vertigo spells while sitting up, and 20% classical BPPV. METHODS: Posturographic recordings were performed in 20 patients with sBPPV and sitting-up vertigo. RESULTS AND DISCUSSION: Seven of the 20 patients had trunk oscillations during the act of sitting up and for a short time immediately afterwards. Based on their findings, the authors propose a new type of BPPV, the so-called Type 2 BPPV (typical complaints of BPPV, no nystagmus in Dix-Hallpike positions but short vertigo spell while sitting up), which may be the result of chronic canalolithiasis within the short arm of a posterior canal. Furthermore, the authors suggest that Type 2 BPPV, which could be identical to sBPPV or constitute a major subgroup of it, occurs frequently among patients with vertigo. For therapy, the authors recommend repetitive sit-ups from the Dix-Hallpike positions to liberate the short arm of the posterior canal from canaloliths.
Asunto(s)
Nistagmo Fisiológico , Vértigo , Anciano , Vértigo Posicional Paroxístico Benigno , Interpretación Estadística de Datos , Mareo/etiología , Conducto Auditivo Externo/patología , Terapia por Ejercicio , Femenino , Humanos , Litiasis/complicaciones , Masculino , Persona de Mediana Edad , Postura/fisiología , Tórax/fisiología , Vértigo/fisiopatología , Vértigo/terapia , Pruebas de Función VestibularRESUMEN
Recent observations suggest that calcyon, a novel single transmembrane protein implicated in schizophrenia and attention-deficit/hyperactivity disorder, regulates clathrin-mediated endocytosis in brain. To explore the role of calcyon in neurotransmission, we investigated its distribution in the neuropil of the primate prefrontal cortex (PFC), striatum (STR) and mediodorsal thalamic nucleus (MD), three brain regions implicated in these neuropsychiatric disorders. Calcyonimmunoreactivity revealed by immunoperoxidase technique, was localized in both pre- and postsynaptic structures including axons, spines and dendrites, as well as myelinated fibers and astroglial processes in all the three brain regions. The morphological diversity of immunopositive boutons suggest that in addition to glutamatergic, calcyon could regulate GABAergic as well as monoaminergic neurotransmission. Consistent with the role of calcyon in endocytosis, calcyon-immunoreactivity was rarely found at the synaptic membrane specializations proper, although it was present in distal compartments of neuronal processes establishing synapses. Given the widespread upregulation of calcyon in schizophrenic brain, these findings underscore a potential association with deficits in a range of neurotransmitter systems in the cortico-basal ganglia-thalamic loop.
Asunto(s)
Ganglios Basales/metabolismo , Ganglios Basales/ultraestructura , Corteza Cerebral/metabolismo , Corteza Cerebral/ultraestructura , Proteínas de la Membrana/metabolismo , Tálamo/metabolismo , Tálamo/ultraestructura , Animales , Axones/metabolismo , Axones/ultraestructura , Femenino , Macaca mulatta , Microscopía Inmunoelectrónica , Modelos Neurológicos , Vías Nerviosas/metabolismo , Vías Nerviosas/ultraestructura , Sinapsis/metabolismo , Sinapsis/ultraestructuraRESUMEN
3D reconstruction from electronmicroscopic (EM) serial sections substantially differs from modeling body parts by linking convoluted planes delivered by CT and NMR. Namely, variations both in relative X-Y position and rotation of the target elements between the adjacent images and also additional problems caused by deformed, deteriorated or missing sections can only be overruled by an aligning paradigm, which exploits all the pixel-level information, and results in an optimal fitting with selected precision. This paper presents a complex computer program called Optimal Alignment, which performs the precise elaboration of X-Y shift and relative rotation of two consecutive images. The required searching process will be customized by setting four independent parameters which relate the span and density of the pixel-scanning basic process. Optimalization of fitting accuracy versus running time can be achieved by a rather short training period. The potential precision of Optimal Alignment based on complex algorithms is far superior to manual aligning of EM photographs with the eye-wrist-mouse facility. The resulted database of alignment orientation parameters can serve as an advanced source for the 3D reconstructing programs. Optimal Alignment software tool (supported by Hungarian Space Office grant TP 138) will be demonstrated on a basal forebrain NPY+ axonal reconstruction, performed in L. Záborszky's laboratory (supported by NIH grant NSO23945).