We demonstrate the feasibility of the 445 nm laser in several laboratory experiments and show clinical cases where photoangiolysis and cutting was possible. However, this is a preliminary report and further systematic studies in greater numbers are warranted.

We investigated cortico-lingual and cortico-orofacial tract function utilizing transcranial magnetic stimulation in 18 consecutive patients with dysarthria due to hemispheric stroke. Delayed responses (conduction time > mean + 2.5 SD of that of 43 controls) or absent responses were considered abnormal. In all patients, motor-cortex stimulation of the lesion side demonstrated absent (13 patients) or delayed (five patients) responses to the tongue bilaterally (17 patients) or unilaterally (one patient). In 14 patients the contralateral orofacial responses were either absent (13 patients) or delayed (one patient). According to the electrophysiological findings, all lesions revealed by CT or MRI, were located within the pyramidal tract at the lower motor cortex (n = 4), the corona radiata (n = 7), and the genu of the internal capsule (n = 3) or its posterior limb (n = 4). We conclude that interruption of the cortico-bulbar tract fibres to muscles involved in articulation is a frequent cause of dysarthria in hemispheric stroke.

Objectives-The pathophysiology of dysarthria can preferentially be studied in patients with the rare lacunar stroke syndrome of "isolated dysarthria". Methods-A single study was carried out on seven consecutive patients with sudden onset of isolated dysarthria due to single ischaemic lesion. The localisation of the lesion was identified using MRI. The corticolingual, cortico-orofacial, and corticospinal tract functions were investigated using transcranial magnetic stimulation. Corticopontocerebellar tract function was assessed using 99m Tc hexamethylpropylene amine oxime-single photon emission computerised tomography (HMPAO-SPECT) in six patients. Sensory functions were evaluated clinically and by somatosensory evoked potentials. Results-Brain MRI showed the lesions to be located in the corona radiata (n=4) and the internal capsule (n=2). No morphological lesion was identified in one patient.Corticolingual tract function was impaired in all patients. In four patients with additional cortico-orofacial tract dysfunction, dysarthria did not diVer from that in patients with isolated corticolingual tract dysfunction. Corticospinal tract functions were normal in all patients. HMPAO-SPECT showed no cerebellar diaschisis, suggesting unimpaired corticopontocerebellar tract function. Sensory functions were not aVected. Conclusion-Interruption of the corticolingual pathways to the tongue is crucial in the pathogenesis of isolated dysarthria after extracerebellar lacunar stroke. (J Neurol Neurosurg Psychiatry 1999;66:495-501)

Narrow band imaging (NBI) is widely used in gastrointestinal, laryngeal, and urological endoscopy. Its original purpose was to visualize vessels and epithelial irregularities. Based on our observation that adding NBI to common white light (WL) improves the contrast of the test bolus in fiberoptic endoscopic evaluation of swallowing (FEES), we now investigated the potential value of NBI in swallowing disorders. 148 FEES images were analyzed from 74 consecutive patients with swallowing disorders, including 74 with and 74 without NBI. All images were evaluated by four dysphagia specialists. Findings were classified according to Rosenbek's penetration-aspiration scale modified for evaluating these FEES images. Intra- and inter-rater reliability was determined as well as observer confidence. A better visualization of the bolus is the main advantage of NBI in FEES. This generally leads to sharper optical contrasts and better detection of small bolus quantities. Accordingly, NBI enhances the detection rate of penetration and aspiration. On average, identification of laryngeal penetration increased from 40 to 73% and of aspiration from 13 to 24% (each p < 0.01) of patients. In contrast to WL alone, the use of NBI also markedly increased the inter- and intra-rater reliability (p < 0.01) and the rating confidence of all experts (p < 0.05). NBI is an easy and cost-effective tool simplifying dysphagia evaluation and shortening FEES evaluation time. It leads to a markedly higher detection rate of pathological findings. The significantly better intra- and inter-rater reliability argues further for a better overall reproducibly of FEES interpretation.