Dyslexia is most often attributed to phonological impairments, manifested in abnormal activation of the left temporal and temporoparietal cortex in response to auditorily presented language and possibly associated with anomalies in the cytoarchitecture and hemispheric symmetry of the plana temporale. The immediate cortical correlate of the severely impaired reading process has, however, remained obscure. Here we report on the distinct time courses of cortical activation in dyslexic and control subjects during passive viewing of single words, tracked with whole-head magnetoencephalography. A striking difference was found in the left inferior temporo-occipital region where intracranial recordings have recently identified word-specific responses within 200 msec after stimulus onset: controls showed a sharp activation at about 180 msec after word presentation, whereas dyslexics failed to activate this area entirely, or showed a slowly increasing late response. Perception of words as specific units thus seems to be impaired in dyslexics.

Multichannel neuromagnetic recordings were used to differentiate signals from the human first (SI) and second (SII) somatosensory cortices and to define representations of body surface in them. The responses from contralateral SI, peaking at 20-40 ms, arose mainly from area 3b, where representations of the leg, hand, fingers, lips and tongue agreed with earlier animal studies and with neurosurgical stimulations and recordings on convexial cortex in man. Representations of the five fingers were limited to a cortical strip of approximately 2 cm in length. Responses from SII peaked 100-140 ms after contra- and ipsilateral stimuli and varied considerably from one subject to another. Signs of somatotopical organization were seen also in SII. Responses of SII were not fully recovered at interstimulus intervals of 8 s.

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Background and Purpose-Numerous contraindications included in the license of alteplase, most of which are not based on scientific evidence, restrict the portion of patients with acute ischemic stroke eligible for treatment with alteplase. We studied whether off-label thrombolysis was associated with poorer outcome or increased rates of symptomatic intracerebral hemorrhage compared with on-label use. Methods-All consecutive patients with stroke treated with intravenous thrombolysis from 1995 to 2008 at the Helsinki University Central Hospital were registered (nϭ1104). After excluding basilar artery occlusions (nϭ119), the study population included 985 patients. Clinical outcome (modified Rankin Scale 0 to 2 versus 3 to 6) and symptomatic intracerebral hemorrhage according to 3 earlier published criteria were analyzed with a logistic regression model adjusting for 21 baseline variables. Results-One or more license contraindications to thrombolysis was present in 51% of our patients (nϭ499). The most common of these were age Ͼ80 years (nϭ159), mild stroke National Institutes of Health Stroke Scale score Ͻ5 (nϭ129), use of intravenous antihypertensives prior to treatment (nϭ112), symptom-to-needle time Ͼ3 hours (nϭ95), blood pressure Ͼ185/110 mm Hg (nϭ47), and oral anticoagulation (nϭ39). Age Ͼ80 years was the only contraindication independently associated with poor outcome (OR, 2.18; 95% CI, 1.27 to 3.73) in the multivariate model. None of the contraindications were associated with an increased risk of symptomatic intracerebral hemorrhage. Conclusions-Off-license thrombolysis was not associated with poorer clinical outcome, except for age Ͼ80 years, nor with increased rates of symptomatic intracerebral hemorrhage. The current extensive list of contraindications should be re-evaluated when data from ongoing randomized trials and observational studies become available. (Stroke.

We applied fMRI and diffusion-weighted MRI to study the segregation of cognitive and motor functions in the human cerebro-cerebellar system. Our fMRI results show that a load increase in a nonverbal auditory working memory task is associated with enhanced brain activity in the parietal, dorsal premotor, and lateral prefrontal cortices and in lobules VII-VIII of the posterior cerebellum, whereas a sensory-motor control task activated the motor/somatosensory, medial prefrontal, and posterior cingulate cortices and lobules V/VI of the anterior cerebellum. The load-dependent activity in the crus I/II had a specific relationship with cognitive performance: This activity correlated negatively with load-dependent increase in RTs. This correlation between brain activity and RTs was not observed in the sensory-motor task in the activated cerebellar regions. Furthermore, probabilistic tractography analysis of the diffusion-weighted MRI data suggests that the tracts between the cerebral and the cerebellar areas exhibiting cognitive load-dependent and sensory-motor activity are mainly projected via separated pontine (feed-forward tracts) and thalamic (feedback tracts) nuclei. The tractography results also indicate that the crus I/II in the posterior cerebellum is linked with the lateral prefrontal areas activated by cognitive load increase, whereas the anterior cerebellar lobe is not. The current results support the view that cognitive and motor functions are segregated in the cerebellum. On the basis of these results and theories of the function of the cerebellum, we suggest that the posterior cerebellar activity during a demanding cognitive task is involved with optimization of the response speed.

Background:  Viral encephalitis is a medical emergency. The prognosis depends mainly on the pathogen and host immunologic state. Correct immediate diagnosis and introduction of symptomatic and specific therapy has a dramatic influence upon survival and reduces the extent of permanent brain injury. Methods:  We searched the literature from 1966 to 2009. Recommendations were reached by consensus. Where there was lack of evidence but consensus was clear, we have stated our opinion as good practice points. Recommendations:  Diagnosis should be based on medical history and examination followed by CSF analysis for protein and glucose levels, cellular analysis, and identification of the pathogen by polymerase chain reaction amplification (recommendation level A) and serology (level B). Neuroimaging, preferably by MRI, is essential (level B). Lumbar puncture can follow neuroimaging when immediately available, but if this cannot be performed immediately, LP should be delayed only under unusual circumstances. Brain biopsy should be reserved only for unusual and diagnostically difficult cases. Patients must be hospitalized with easy access to intensive care units. Specific, evidence‐based, antiviral therapy, acyclovir, is available for herpes encephalitis (level A) and may also be effective for varicella‐zoster virus encephalitis. Ganciclovir and foscarnet can be given to treat cytomegalovirus encephalitis, and pleconaril for enterovirus encephalitis (IV class evidence). Corticosteroids as an adjunct treatment for acute viral encephalitis are not generally considered to be effective, and their use is controversial, but this important issue is currently being evaluated in a large clinical trial. Surgical decompression is indicated for impending uncal herniation or increased intracranial pressure refractory to medical management.

Background: Cortical gray matter reductions and cerebrospinal fluid (CSF) increases are robust correlates of schizophrenia, but their relationships to obstetric and other etiologic risk factors remain to be established.

Although PLOSL in most patients manifests by bone fractures, some patients do not show any osseous symptoms and signs before the onset of neurologic manifestations. Consequently, patients with frontal-type dementia of unknown origin should be investigated by x-ray of ankles and wrists. The current results suggest early basal ganglia involvement in PLOSL.