Is it still speech? Different processing strategies in learning to discriminate stimuli in the transition from speech to non-speech including feedback evaluation.

Processing of speech was investigated by using stimuli gradually changing from speech (vowels) to non-speech (spectral rotated vowels). Stimuli were presented in descending levels of vocalization blends, from pure speech to non-speech, through step-wise combinations, resulting in ambiguous versions of the sounds. Participants performed a two-alternative forced choice task: categorization of sounds were made according to whether they contained more speech or non-speech. Performance feedback was presented visually on each trial. Reaction times (RT) after sound presentation, and functional magnetic resonance imaging (fMRI) data during auditory and visual processing, were analyzed. RT data suggested individual differences with a distinct group, good performers, functioning better in distinguishing stimuli with a higher degree of ambiguous blends compared to poor performers, who were not able to distinguish these stimuli correctly. fMRI data confirmed this finding. During auditory stimulation, good performers showed neural activation in the ventral auditory pathway, including the primary auditory cortex and the anterior superior temporal sulcus (responsible for speech processing). Poor performers, in contrast, showed neural activation in the dorsal auditory pathway, including the bilateral superior temporal gyrus. Group differences were also found for visual feedback processing. Differences observed between the groups were interpreted as reflecting different neural processing strategies.

Performance of repetitive alternating elbow movements in Parkinson's disease.

BACKGROUND: Bradydiadochokinesia is one main clinical symptom in idiopathic Parkinson's disease (IPD). The pathogenesis of bradydiadochokinesia is not completely clear. METHODS: Fifteen patients with IPD and 15 age-matched healthy volunteers had to perform rhythmic alternating flexion and extension movements in the elbow joint. The rhythm was provided auditorily by a click tone stimulator. Six maneuvers (spatial extents of 48 and 83° at frequencies of 0.45, 0.75 and 1.25 Hz) had to be absolved. The potentiometer converted the horizontal forearm movements into a variable voltage. RESULTS: The duration of single movements varied more significantly in patients than in controls (p < 0.05; Mann-Whitney U test). Patients executed all conditions more slowly than controls, but this difference was only significant at the most difficult condition (83° at 1.25 Hz; p < 0.01). The movement amplitudes or their variability were not significantly different at any condition. No parameter correlated significantly with the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS) or with the duration of disease. CONCLUSION: An insufficient temporal coordination contributes to bradydiadochokinesia in IPD. This deficit occurs independently of other parkinsonian cardinal motor symptoms.

Separating intra-modal and across-modal training effects in visual working memory: an fMRI investigation.

Working memory training is a useful tool to examine dissociations between specific working memory processes. Although current models propose a distinction between modality-specific working memory processes, to our knowledge no study has directly examined the effects of visual versus auditory working memory training. Functional magnetic resonance imaging was used to investigate whether visual working memory processes can be trained specifically and whether those effects can be separated from across-modal training effects. We found decidedly larger training gains after visual working memory training compared with auditory or no training on a visual 2-back task. These effects were accompanied by specific training-related decreases in the right middle frontal gyrus arising from visual training only. Likewise, visual and auditory training led to decreased activations in the superior portion of the right middle frontal gyrus and the right posterior parietal lobule. We infer that the combination of effects resulted from increased neural efficiency of intra-modal (visual) processes on the one hand and of across-modal (general control) processes on the other hand. Therefore, visual processes of working memory can be trained specifically, and these effects can be functionally dissociated from alterations in general control processes common to both working memory trainings.

Influence of carotid artery stenting on cognitive function.

INTRODUCTION: There have only been a few studies on cognitive changes in patients with carotid occlusive disease, and the results of these show major discrepancies in the extent to which treatment affects neuropsychological function. We sought to clarify these discrepancies by evaluating the effects of carotid artery stenting (CAS) on the cognitive function. METHODS: Forty-one asymptomatic CAS patients were administered a test battery of neuropsychological tests measuring cognitive speed and memory function before and 3 months after the procedure. A control group was also evaluated. To test for thromboembolic lesions, diffusion-weighted imaging was used. RESULTS: CAS led to a significant increase in cognitive speed (p<0.001) but did not afford any change in memory function. This was regardless of the degree or side of stenosis or patient age or gender. CONCLUSION: CAS significantly improved functions that involve cognitive speed. Earlier studies did not differentiate between speed and memory tests and thus might have missed these changes. Further studies correlating changes in brain perfusion with increase in cognitive speed are needed.

Impairment of fronto-striatal and parietal cerebral networks correlates with attention deficit hyperactivity disorder (ADHD) psychopathology in adults - a functional magnetic resonance imaging (fMRI) study.

Attention deficit hyperactivity disorder (ADHD) is a common, genetically transmitted common childhood-onset disorder with a high rate of persistence in adulthood. Although many studies have shown anatomical and functional abnormalities in children and adolescents, studies with adult patients are rare. Nineteen adults with ADHD (11 ADHD, combined type; 8 ADHD, partially remitted) and 17 controls were included in this functional magnetic resonance imaging (fMRI) study. Brain activation was investigated with a continuous performance test (CPT). Impaired activation of a fronto-striatal and a parietal attentional network was observed during the NoGo condition in ADHD subjects. Correlations of reduced activity of the caudate nuclei, the anterior cingulate cortex, and parietal cortical structures, as well as increased activity in the insular cortex, with inattention and impulsivity symptom scores were found. The activation patterns were similar to those known from children and adolescents with ADHD. In conclusion we found not only a widespread dysfunction of brain regions that are involved in cognitive processing in adults with ADHD compared with controls, but also correlations between symptom severity and dysfunction of neuronal systems across adult subjects with a history of ADHD in childhood but whose symptoms did (persistent ADHD) and did not (not persistent ADHD) qualify for a full diagnosis of ADHD in adulthood.

fMRI and acoustic analyses reveal neural correlates of gestural complexity and articulatory effort within bilateral inferior frontal gyrus during speech production.

In an event-related fMRI study of overt speech production, we investigated the relationship between gestural complexity and underlying brain activity within bilateral inferior frontal gyrus (IFG). We operationalized gestural complexity as the number of active articulatory tiers (glottal, oral, nasal) and the degree of fine-grained temporal coordination between tiers (low, high). Forty-three neurotypical participants produced three types of highly-frequent non-word CV-syllable sequences, which differ systematically in gestural complexity (simple: ['dadada], intermediate: ['tatata], complex: ['nanana]). Comparing blood oxygen level-dependent (BOLD) responses across complexity conditions revealed that syllables with greater gestural complexity elicited increased activation patterns. Moreover, when durational parameters were included as covariates in the analyses, significant effects of articulatory effort were found over and above the effects of complexity. The results suggest that these differences in BOLD-response reflect the differential contribution of articulatory mechanisms that are required to produce phonologically distinct speech sounds.

Perception of biological motion in autism spectrum disorders.

In individuals with autism or autism-spectrum-disorder (ASD), conflicting results have been reported regarding the processing of biological motion tasks. As biological motion perception and recognition might be related to impaired imitation, gross motor skills and autism specific psychopathology in individuals with ASD, we performed a functional MRI study on biological motion perception in a sample of 15 adolescent and young adult individuals with ASD and typically developing, age, sex and IQ matched controls. Neuronal activation during biological motion perception was compared between groups, and correlation patterns of imitation, gross motor and behavioral measures with neuronal activation were explored. Differences in local gray matter volume between groups as well as correlation patterns of psychopathological measures with gray matter volume were additionally compared. On the behavioral level, recognition of biological motion was assessed by a reaction time (RT) task. Groups differed strongly with regard to neuronal activation and RT, and differential correlation patterns with behavioral as well as with imitation and gross motor abilities were elicited across and within groups. However, contrasting with the initial hypothesis, additional differences between groups were observed during perception and recognition of spatially moving point lights in general irrespective of biological motion. Results either point towards difficulties in higher-order motion perception or in the integration of complex motion information in the association cortex. This interpretation is supported by differences in gray matter volume as well as correlation with repetitive behavior bilaterally in the parietal cortex and the right medial temporal cortex. The specific correlation of neuronal activation during biological motion perception with hand-finger imitation, dynamic balance and diadochokinesis abilities emphasizes the possible relevance of difficulties in biological motion perception or impaired self-other matching for action imitation and gross motor difficulties in individuals with ASD.

Compensatory hyperactivations as markers of latent working memory dysfunctions in patients with obsessive-compulsive disorder: an fMRI study.

OBJECTIVE: Behavioural studies have implicated working memory (WM) deficits in obsessive-compulsive disorder (OCD). However, findings are inconsistent, which could be explained by compensation strategies used by a subgroup of OCD patients. To test this hypothesis, we examined patients without a behavioural deficit in WM during performance of different WM tasks using functional magnetic resonance imaging (fMRI). METHODS: We scaned 11 patients and 11 matched control subjects while they performed 3 verbal and spatial item-recognition tasks. RESULTS: Patients and healthy subjects engaged the same set of brain regions. However, in direct comparison, the patients exhibited significantly greater task-related activation in several frontal and parietal brain areas known to underlie WM. CONCLUSION: Patients without manifest WM deficits exhibit increased activation in frontal and parietal brain areas relative to healthy subjects during WM task performance. These hyperactivations may permit them to compensate for reduced efficiency of their WM systems and may thus serve as markers of latent WM dysfunctions.

Heidelberg Neuro-Music Therapy Restores Attention-Related Activity in the Angular Gyrus in Chronic Tinnitus Patients.

Background: Tinnitus is the perception of a phantom sound without external acoustic stimulation. Recent tinnitus research suggests a relationship between attention processes and tinnitus-related distress. It has been found that too much focus on tinnitus comes at the expense of the visual domain. The angular gyrus (AG) seems to play a crucial role in switching attention to the most salient stimulus. This study aims to evaluate the involvement of the AG during visual attention tasks in tinnitus sufferers treated with Heidelberg Neuro-Music Therapy (HNMT), an intervention that has been shown to reduce tinnitus-related distress. Methods: Thirty-three patients with chronic tinnitus, 45 patients with recent-onset tinnitus, and 35 healthy controls were tested. A fraction of these (21/21/22) were treated with the "compact" version of the HNMT lasting 1 week with intense treatments, while non-treated participants were included as passive controls. Visual attention was evaluated during functional Magnet-Resonance Imaging (fMRI) by a visual Continous Performance Task (CPT) using letter-based alarm cues ("O" and "X") appearing in a sequence of neutral letters, "A" through "H." Participants were instructed to respond via button press only if the letter "O" was followed by the letter "X" (GO condition), but not to respond if a neutral letter appeared instead (NOGO condition). All participants underwent two fMRI sessions, before and after a 1-week study period. Results: The CPT results revealed a relationship between error rates and tinnitus duration at baseline whereby the occurrence of erroneous "GO omissions" and the reaction time increased with tinnitus duration. Patients with chronic tinnitus who were treated with HNMT had decreasing error rates (fewer GO omissions) compared to treated recent-onset patients. fMRI analyses confirmed greater activation of the AG during CPT in chronic patients after HNMT treatment compared to treated recent-onset patients. Conclusions: Our findings suggest that HNMT treatment helps shift the attention from the auditory phantom percept toward visual cues in chronic tinnitus patients and that this shift in attention may involve the AG.

Heidelberg Neuro-Music Therapy Enhances Task-Negative Activity in Tinnitus Patients.

Background: Suffering from tinnitus causes mental distress in most patients. Recent findings point toward a diminished activity of the brain's default-mode network (DMN) in subjects with mental disorders including depression or anxiety and also recently in subjects with tinnitus-related distress. We recently developed a therapeutic intervention, namely the Heidelberg Neuro-Music Therapy (HNMT), which shows an effective reduction of tinnitus-related distress following a 1-week short-term treatment. This approach offers the possibility to evaluate the neural changes associated with the improvements in tinnitus distress. We previously reported gray matter (GM) reorganization in DMN regions and in primary auditory areas following HNMT in cases of recent-onset tinnitus. Here we evaluate on the same patient group, using functional MRI (fMRI), the activity of the DMN following the improvements tinnitus-related distress related to the HNMT intervention. Methods: The DMN activity was estimated by the task-negative activation (TNA) during long inter-trial intervals in a word recognition task. The level of TNA was evaluated twice, before and after the 1-week study period, in 18 treated tinnitus patients ("treatment group," TG), 21 passive tinnitus controls (PTC), and 22 active healthy controls (AC). During the study, the participants in TG and AC groups were treated with HNMT, whereas PTC patients did not receive any tinnitus-specific treatment. Therapy-related effects on DMN activity were assessed by comparing the pairs of fMRI records from the TG and PTC groups. Results: Treatment of the TG group with HNMT resulted in an augmented DMN activity in the PCC by 2.5% whereas no change was found in AC and PTC groups. This enhancement of PCC activity correlated with a reduction in tinnitus distress (Spearman Rho: -0.5; p < 0.005). Conclusion: Our findings show that an increased DMN activity, especially in the PCC, underlies the improvements in tinnitus-related distress triggered by HNMT and identify the DMN as an important network involved in therapeutic improvements.

Immunohistochemical detection of dUTPase in intracranial tumors.

The nuclear isoform of deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase, OMIM *601266, EC 3.6.1.23) is immunohistochemically detectable in all proliferating tissues and may thus be a useful adjunct for the grading of tumors analogous to Ki-67 labeling. A hundred and twenty-seven human intracranial tumors, including 56 astrocytomas, 12 oligodendrogliomas, 8 oligoastrocytomas, 34 meningiomas, 7 ependymomas, and 10 metastatic carcinomas, were stained using the monoclonal rat anti-human dUTPase antibody (clone 3E6) with formalin-fixed and paraffin-embedded tissue. The labeling indices were compared with those obtained with the proliferation marker Ki-67 on parallel tissue sections. All tumors contained dUTPase-positive nuclei, whereas the percentage of positive tumor cells generally increased with grade of malignancy. Meningiomas of higher grades, i.e., World Health Organization (WHO) grades II and III, contained additional cells with cytoplasmic reactivity. There were usually fewer dUTPase- than Ki-67-positive nuclei detectable. Unlike Ki-67, dUTPase was not detectable in mitotic figures. Labeling indices for dUTPase, but not for Ki-67, showed significant differences between all 3 WHO grades of diffuse astrocytomas. In summary, dUTPase staining provides a useful measure of cell proliferation distinct from that offered by Ki-67 labeling. It proved particularly useful for the evaluation of diffuse astrocytomas.

SNARC meets SPARC in fMRI--Interdependence of compatibility effects depends on semantic content.

BACKGROUND: Stimulus-response compatibility (SRC) plays a major role in choice-reaction tasks. In specific cases, SRC leads to phenomena like the Spatial Numerical Association of Response Codes (SNARC) or the Spatial Pitch Association of Response Codes (SPARC) effect: small numbers or low pitches lead to faster responses when answered with the left hand, whereas large numbers or high pitches lead to faster responses when answered with the right hand. The previous study, investigating the combination of SNARC and SPARC with numbers spoken in different pitch heights, points towards an interdependency of both SNARC and SPARC compatibility effects, suggesting an automatic process. METHODS: In the present event-related functional magnetic resonance imaging (fMRI) study, we investigated the underlying neural activity when SNARC and SPARC are combined within the same auditory stimulus (numerical condition). Additionally, we included a categorical condition (the words "small" and "large") as variation of the stimulus type. RESULTS: We found neither an effect for SNARC nor for SPARC Compatibility in the neuronal data, whereas SNARC Compatibility was found in the behavioral data. According to the behavioral as well as the neuronal data, in the bilateral auditory cortex, SNARC and SPARC Compatibility interacts with Stimulus Type, i.e., whether numerical or categorical stimuli were presented. CONCLUSIONS: We concluded that both effects are interdependent and that this interaction strongly depends on the semantic information.

Cortical reorganization in recent-onset tinnitus patients by the Heidelberg Model of Music Therapy.

Pathophysiology and treatment of tinnitus still are fields of intensive research. The neuroscientifically motivated Heidelberg Model of Music Therapy, previously developed by the German Center for Music Therapy Research, Heidelberg, Germany, was applied to explore its effects on individual distress and on brain structures. This therapy is a compact and fast application of nine consecutive 50-min sessions of individualized therapy implemented over 1 week. Clinical improvement and long-term effects over several years have previously been published. However, the underlying neural basis of the therapy's success has not yet been explored. In the current study, the therapy was applied to acute tinnitus patients (TG) and healthy active controls (AC). Non-treated patients were also included as passive controls (PTC). As predicted, the therapeutic intervention led to a significant decrease of tinnitus-related distress in TG compared to PTC. Before and after the study week, high-resolution MRT scans were obtained for each subject. Assessment by repeated measures design for several groups (Two-Way ANOVA) revealed structural gray matter (GM) increase in TG compared to PTC, comprising clusters in precuneus, medial superior frontal areas, and in the auditory cortex. This pattern was further applied as mask for general GM changes as induced by the therapy week. The therapy-like procedure in AC also elicited similar GM increases in precuneus and frontal regions. Comparison between structural effects in TG vs. AC was calculated within the mask for general GM changes to obtain specific effects in tinnitus patients, yielding GM increase in right Heschl's gyrus, right Rolandic operculum, and medial superior frontal regions. In line with recent findings on the crucial role of the auditory cortex in maintaining tinnitus-related distress, a causative relation between the therapy-related GM alterations in auditory areas and the long-lasting therapy effects can be assumed.

Configuration of the optic chiasm in humans with albinism as revealed by magnetic resonance imaging.

PURPOSE: To determine whether the size and configuration of the optic chiasm in humans with albinism is different from that in normal control subjects. METHODS: Seventeen patients and 15 control subjects underwent magnetic resonance imaging of the entire head. Images were reformatted to the chiasm region and analyzed with observer-independent morphometry and measurements by a blinded observer. RESULTS: The albino group showed significantly smaller chiasmatic widths, smaller optic nerves and tracts, and wider angles between nerves and tracts. Statistical morphometry showed a different configuration of the optic chiasm. CONCLUSIONS: Size and configuration of the optic chiasm in humans with albinism are distinctly different from those in normal control subjects and reflect the atypical crossing of optic fibers.

Influence of proprioceptive input on parkinsonian tremor.

Previous studies have shown a modification of parkinsonian tremor (PT) by proprioceptive input induced by passive joint movements. The authors investigated the impact of electrically evoked proprioceptive input on PT. In eight patients with PT they recorded surface EMG from the opponens pollicis muscle, and forearm extensors and flexors. Rhythmic electrical stimulation was applied to the ipsilateral median nerve at the wrist using a submaximal stimulus intensity and stimulus frequencies between two stimuli per second and five stimuli per second. The tremor frequency did not adapt to the stimulus frequency. Tremor frequency of parkinsonian resting tremor increased significantly in the directly stimulated opponens pollicis muscle (mean +/- standard deviation, 4.35 +/- 0.64 Hz without stimulation versus 4.53 +/- 0.68 Hz with stimulation; P < 0.05, paired t-test), the not directly stimulated forearm muscles (4.90 +/- 0.72 Hz versus 5.18 +/- 0.73 Hz, P < 0.001), and the upper arm muscles (5.13 +/- 0.61 Hz versus 5.36 +/- 0.68 Hz, P < 0.01). Furthermore, the parkinsonian postural tremor accelerated significantly during ipsilateral median nerve stimulation (5.31 +/- 0.99 Hz versus 5.44 +/- 1.03 Hz, P < 0.05). Parkinsonian resting tremor in the forearm muscles also accelerated significantly during ipsilateral ulnar nerve stimulation (4.85 +/- 0.57 Hz versus 5.05 +/- 0.65 Hz, P < 0.05). Contralateral median nerve stimulation had no significant effect. These results suggest a close interaction between proprioceptive input and PT generation.

Selective transfer of visual working memory training on Chinese character learning.

Previous research has shown a systematic relationship between phonological working memory capacity and second language proficiency for alphabetic languages. However, little is known about the impact of working memory processes on second language learning in a non-alphabetic language such as Mandarin Chinese. Due to the greater complexity of the Chinese writing system we expect that visual working memory rather than phonological working memory exerts a unique influence on learning Chinese characters. This issue was explored in the present experiment by comparing visual working memory training with an active (auditory working memory training) control condition and a passive, no training control condition. Training induced modulations in language-related brain networks were additionally examined using functional magnetic resonance imaging in a pretest-training-posttest design. As revealed by pre- to posttest comparisons and analyses of individual differences in working memory training gains, visual working memory training led to positive transfer effects on visual Chinese vocabulary learning compared to both control conditions. In addition, we found sustained activation after visual working memory training in the (predominantly visual) left infero-temporal cortex that was associated with behavioral transfer. In the control conditions, activation either increased (active control condition) or decreased (passive control condition) without reliable behavioral transfer effects. This suggests that visual working memory training leads to more efficient processing and more refined responses in brain regions involved in visual processing. Furthermore, visual working memory training boosted additional activation in the precuneus, presumably reflecting mental image generation of the learned characters. We, therefore, suggest that the conjoint activity of the mid-fusiform gyrus and the precuneus after visual working memory training reflects an interaction of working memory and imagery processes with complex visual stimuli that fosters the coherent synthesis of a percept from a complex visual input in service of enhanced Chinese character learning.

Visual processing of biological motion in children and adolescents with attention-deficit/hyperactivity disorder: an event related potential-study.

Attention-deficit/hyperactivity disorder (ADHD) is often accompanied by problems in social behaviour, which are sometimes similar to some symptoms of autism-spectrum disorders (ASD). However, neuronal mechanisms of ASD-like deficits in ADHD have rarely been studied. The processing of biological motion-recently discussed as a marker of social cognition-was found to be disrupted in ASD in several studies. Thus in the present study we tested if biological motion processing is disrupted in ADHD. We used 64-channel EEG and spatio-temporal source analysis to assess event-related potentials associated with human motion processing in 21 children and adolescents with ADHD and 21 matched typically developing controls. On the behavioural level, all subjects were able to differentiate between human and scrambled motion. But in response to both scrambled and biological motion, the N200 amplitude was decreased in subjects with ADHD. After a spatio-temporal dipole analysis, a human motion specific activation was observable in occipital-temporal regions with a reduced and more diffuse activation in ADHD subjects. These results point towards neuronal determined alterations in the processing of biological motion in ADHD.

Visual event-related potentials to biological motion stimuli in autism spectrum disorders.

Atypical visual processing of biological motion contributes to social impairments in autism spectrum disorders (ASD). However, the exact temporal sequence of deficits of cortical biological motion processing in ASD has not been studied to date. We used 64-channel electroencephalography to study event-related potentials associated with human motion perception in 17 children and adolescents with ASD and 21 typical controls. A spatio-temporal source analysis was performed to assess the brain structures involved in these processes. We expected altered activity already during early stimulus processing and reduced activity during subsequent biological motion specific processes in ASD. In response to both, random and biological motion, the P100 amplitude was decreased suggesting unspecific deficits in visual processing, and the occipito-temporal N200 showed atypical lateralization in ASD suggesting altered hemispheric specialization. A slow positive deflection after 400 ms, reflecting top-down processes, and human motion-specific dipole activation differed slightly between groups, with reduced and more diffuse activation in the ASD-group. The latter could be an indicator of a disrupted neuronal network for biological motion processing in ADS. Furthermore, early visual processing (P100) seems to be correlated to biological motion-specific activation. This emphasizes the relevance of early sensory processing for higher order processing deficits in ASD.

Proximal protection with the Gore PAES can reduce DWI lesion size in high-grade stenosis during carotid stenting.

AIMS: The aim was to determine the incidence of new ischaemic lesions on diffusion-weighted MR imaging (DWI) in a non-randomised cohort of patients after protected and unprotected carotid artery stent placement using the Parodi Anti-Emboli System (PAES). METHODS AND RESULTS: A retrospective review was conducted on 269 patients who received DWI prior to, and 24-72 hours after, stent placement. All patients were enrolled in one centre. Forty patients stented with the PAES device were matched with 229 patients stented without protection (control group). New diffusion restriction on DWI was detected in 25.8% (PAES) versus 32.3% (control group); p=0.64. On average there were 0.7 lesions (PAES) versus 0.8 lesions (control group) per patient. The area of lesions was 1.7 (PAES) versus 5.6 mm2. In a subanalysis of patients (32 PAES, 148 non-protected) with >80% stenosis, the area of restricted diffusion was less when proximal protection was used (p<0.05). The number and area of DWI lesions did not differ on the contralateral, non-stented side. When the PAES system was used, patients were more likely not to have any lesion at all (p=0.028). CONCLUSIONS: In high-grade stenosis, the use of the Gore PAES device significantly reduced the area of new DWI lesions and patients were more likely not to have any new DWI lesion at all.

Different factors influence recanalisation rate after coiling in ruptured and unruptured intracranial aneurysms.

BACKGROUND: Most studies evaluating long-term efficacy after coil embolisation of intracranial aneurysms have not differentiated between ruptured and unruptured aneurysms. OBJECTIVES: The aim of this study was to analyse factors that influence recanalisation in ruptured and unruptured aneurysms. METHODS: We performed a retrospective analysis of 182 (98 ruptured, 84 unruptured) aneurysms, treated with coil embolisation alone that received follow-up with digital substraction angiography (DSA). RESULTS: At 6 months 26% of the aneurysms showed recanalisation. Multivariate variance analysis revealed that different factors influenced recanalisation in ruptured and unruptured aneurysms. In ruptured aneurysms patient age was a determinant, with younger patients recanalising more frequently than older ones (p = 0.016). Also, low initial packing density led to higher recanalisation rates (p = 0.015) than higher packing. In the unruptured aneurysm group these factors were not significant. Here, only a larger aneurysm volume led to higher recanalisation rates (p = 0.027). CONCLUSIONS: Our data suggest that in ruptured aneurysms, high packing density is a key factor to prevent recanalisation, while in unruptured aneurysms, aneurysm volume is the main predictor for recanalisation.