Cerebellar regions involved in adaptation to force field and visuomotor perturbation.

Studies with patients and functional magnetic resonance imaging investigations have demonstrated that the cerebellum plays an essential role in adaptation to visuomotor rotation and force field perturbation. To identify cerebellar structures involved in the two tasks, we studied 19 patients with focal lesions after cerebellar infarction. Focal lesions were manually traced on magnetic resonance images and normalized using a new spatially unbiased template of the cerebellum. In addition, we reanalyzed data from 14 patients with cerebellar degeneration using voxel-based morphometry. We found that adjacent regions with only little overlap in the anterior arm area (lobules IV to VI) are important for adaptation in both tasks. Although adaptation to the force field task lay more anteriorly (lobules IV and V), lobule VI was more important for the visuomotor task. In addition, regions in the posterolateral cerebellum (Crus I and II) contributed to both tasks. No consistent involvement of the posterior arm region (lobule VIII) was found. Independence of the two kinds of adaptation is further supported by findings that performance in one task did not correlate to performance in the other task. Our results show that the anterior arm area of the cerebellum is functionally divided into a more posterior part of lobule VI, extending into lobule V, related to visuomotor adaption, and a more anterior part including lobules IV and V, related to force field adaption. The posterolateral cerebellum may process common aspects of both tasks.

Impaired prehension is associated with lesions of the superior and inferior hand representation within the human cerebellum.

Impairment of patients with cerebellar disease in prehension is well recognized. So far specific localizations within the human cerebellum associated with the impairment have rarely been assessed. To address this question we performed voxel-based lesion symptom mapping (VLSM) in patients with chronic focal cerebellar lesions in relation to specific deficits in prehensile movements. Patients with stroke within the posterior inferior cerebellar artery territory (n = 13) or the superior cerebellar artery (SCA) territory (n = 7) and corresponding control subjects were included in the study. Participants reached out, grasped, and lifted an object with either the left or right hand and with fast or normal movement speed. Both kinematic and grip-force parameters were recorded. Magnetic resonance imaging anatomical scans of the cerebellum were acquired, and lesions were marked as regions of interest. For VLSM analysis, a nonparametric test (Brunner-Munzel) was applied. Cerebellar patients showed clear abnormalities in hand transport (impaired movement speed and straightness) and, to a lesser degree, in hand shaping (increased finger touch latencies) while grip function was preserved. Deficits were most prominent in patients with SCA lesions and for ipsilesional, fast movements. Disorders in hand transport may be more difficult to compensate than deficits in hand shaping and grip-force control in chronic focal lesions of the cerebellum because of higher demands on predictive control of interaction torques. Lesions of the superior cerebellar cortex (lobules IV, V, VI) were associated with slower hand transport, whereas lesions of both superior (lobules VI, V, VI) and inferior cerebellar cortex (lobules VII, VIII) were associated with impaired movement straightness. These findings show that both the superior and inferior hand representations within the cerebellum contribute to hand transport during prehensile movements; however, they may have a different functional role.

Recovery of upper limb function after cerebellar stroke: lesion symptom mapping and arm kinematics.

BACKGROUND AND PURPOSE: Loss of movement coordination is the main postacute symptom after cerebellar infarction. Although the course of motor recovery has been described previously, detailed kinematic descriptions of acute stage ataxia are rare and no attempt has been made to link improvements in motor function to measures of neural recovery and lesion location. This study provides a comprehensive assessment of how lesion site and arm dysfunction are associated in the acute stage and outlines the course of upper limb motor recovery for the first 4 months after the infarction. METHODS: Sixteen adult patients with cerebellar stroke and 11 age-matched healthy controls participated. Kinematics of goal-directed and unconstrained finger-pointing movements were measured at the acute stage and in 2-week and 3-month follow-ups. MRI data were obtained for the acute and 3-month follow-up sessions. A voxel-based lesion map subtraction analysis was performed to examine the effect of ischemic lesion sites on kinematic performance. RESULTS: In the acute stage, nearly 70% of patients exhibited motor slowing with hand velocity and acceleration maxima below the range of the control group. MRI analysis revealed that in patients with impaired motor performance, lesions were more common in paravermal lobules IV/V and affected the deep cerebellar nuclei. Stroke affecting the superior cerebellar artery led to lower motor performance than infractions of the posterior cerebellar artery. By the 2-week-follow-up, hand kinematics had improved dramatically (gains in acceleration up to 86%). Improvements between the 2-week and the 3-month-follow-ups were less pronounced. CONCLUSIONS: In the acute stage, arm movements were mainly characterized by abnormal slowness (bradykinesia) and not dyscoordination (ataxia). The motor signs were associated with lesions in paravermal regions of lobules IV/V and the deep cerebellar nuclei. Motor recovery was fast, with the majority of gains in upper limb function occurring in the first 2 weeks after the acute phase.

Balance control in sitting and standing in children and young adults with benign cerebellar tumors.

Children and young adolescents with chronic surgical cerebellar lesions show persistent balance control problems during standing when lesions affect the deep cerebellar fastigial and adjacent interposed nuclei. The purpose of this study is to confirm that the same lesion sites are also associated with permanent signs of trunkal ataxia during sitting. A second aim is to demonstrate that examining the postural control of patients while sitting or standing on a foam cushion may constitute a simple clinical exam yielding results commensurate to a more involved dynamic posturography exam. Balance control was assessed in 16 patients after surgery of a benign cerebellar tumor in chronic state and healthy age- and gender-matched control subjects. Using an ultrasound-based kinematic recording system, trunkal and shoulder sway was measured during sitting and standing in different conditions. High-resolution MRI scans were acquired in the cerebellar patients. Voxel-wise statistical lesion symptom mapping was performed to compare lesioned areas between affected and unaffected patients in a given condition using χ² tests. During sitting, 56% of cerebellar patients exhibited trunkal sway outside the range of healthy controls, and 87.5% of cerebellar patients revealed abnormal sway patterns during standing. Abnormalities were most pronounced when visual information was absent, and somatosensory information became unreliable and/or when the base of support along the medio-lateral axis was minimized during tandem stance. Lesion symptom mapping revealed that pathological values in the behavior data were more likely in patients with surgical lesions involving the fastigial nuclei (NF) and adjacent interposed nuclei (NI). In patients with surgery <1-year lesions of the inferior cerebellar vermis also had an impact on balance function. Our results corroborate previous evidence that the extent of permanent damage to the deep cerebellar nuclei greatly impacts on the recovery on balance function.

Megalographia in children with cerebellar lesions and in children with attention-deficit/hyperactivity disorder.

Structural changes of the cerebellum have been reported in attention-deficit/hyperactivity disorder (ADHD) in several studies. The cerebellum is a structure essential for motor coordination and motor learning. Beside behavioral deficits, children with ADHD often show slight motor abnormalities. In the present study, handwriting was examined in both children with ADHD and children with cerebellar lesions. By writing the same sentence several times, letter height increased in the ADHD and cerebellar groups but not in controls. Comparable disorders of handwriting in cerebellar and ADHD children support previous studies, which suggest a contribution of cerebellar dysfunction to motor abnormalities in ADHD. However, an involvement of non-cerebellar dysfunctions in ADHD cannot be excluded.

Aphasia and neglect are uncommon in cerebellar disease: negative findings in a prospective study in acute cerebellar stroke.

The aim of the present study was to examine if the most frequent cognitive disorders after cortical damage with a well-known cerebral lateralization, namely aphasia, neglect and extinction, are present in an unselected series of continuously admitted patients with acute cerebellar stroke. Twenty-two adults with acute cerebellar stroke were compared with 22 age- and education-matched healthy control subjects. High-resolution magnetic resonance images showed infarctions of the left cerebellar hemisphere in 12 and of the right hemisphere in ten patients. Standard aphasia tests revealed no statistically significant difference comparing patients with right- and left-sided ischemia and controls, whereas patients with left-sided ischemia showed mild deficits in a verb generation task. Neglect and extinction tasks revealed no significant differences between groups. Our findings support previous observations in the literature that cerebellar patients frequently perform within the normal range in standard neuropsychological tests. This does not exclude, however, that abnormalities may be present in more sophisticated testing of language and visuospatial functions.

Visuomotor adaptive improvement and aftereffects are impaired differentially following cerebellar lesions in SCA and PICA territory.

The aim of the present study was to elucidate the contribution of the superior and posterior inferior cerebellum to adaptive improvement and aftereffects in a visuomotor adaptation task. Nine patients with ischemic lesions within the territory of the posterior inferior cerebellar artery (PICA), six patients with ischemic lesions within the territory of the superior cerebellar artery (SCA) and 17 age-matched controls participated. All subjects performed center-out reaching movements under 60 degrees rotation of visual feedback. For the assessment of aftereffects, we tested retention of adaptation and de-adaptation under 0 degrees visual rotation. From this data we also quantified five measures of motor performance. Cerebellar lesion-symptom mapping was performed using magnetic resonance imaging subtraction analysis. Adaptive improvement during 60 degrees rotation was significantly degraded in PICA patients and even more in SCA patients. Subtraction analysis revealed that posterior (Crus I) as well as anterior cerebellar regions (lobule V) showed a common overlap related to deficits in adaptive improvement. However, for aftereffect measures as well as for motor performance variables only SCA patients, but not PICA patients showed significant differences to control subjects. Subtraction analysis showed that affection of lobules V and VI were more common in patients with impaired retention and de-adaptation, respectively. Data shows that areas both within the superior and posterior inferior cerebellum are involved in adaptive improvement. However, only the superior cerebellum including lobules V and VI appears to be important for aftereffects and therefore true adaptive ability.

Timing of conditioned eyeblink responses is impaired in children with attention-deficit/hyperactivity disorder.

Structural changes of the cerebellum have been reported in several psychiatric diseases like schizophrenia, autism and attention-deficit/hyperactivity disorder (ADHD). Beside behavioral deficits children with ADHD often show slight motor abnormalities. Cerebellar malfunction may contribute. The cerebellum is a structure essential for motor coordination, various forms of motor learning and timing of motor responses. In the present study, eyeblink conditioning was applied to investigate learning and timing of motor responses both in children with ADHD and children with cerebellar lesions. Acquisition, timing and extinction of conditioned eyeblink responses were investigated in children with ADHD, children with chronic surgical cerebellar lesions and controls using a standard delay paradigm with two different interstimulus intervals. Timing of conditioned eyeblink responses was significantly impaired in children with ADHD in the long interstimulus interval condition. Also in children with cerebellar lesions conditioned responses (CR) tended to occur earlier than in controls. Incidences of CRs were significantly reduced in children with cerebellar lesions and tended to be less in children with ADHD than in controls. Extinction of the CRs was impaired in children with cerebellar lesions in both interstimulus interval conditions and in children with ADHD in the long interstimulus interval condition. Cerebellar malfunction may contribute to disordered eyeblink conditioning in ADHD. However, because CR abnormalities differed between ADHD and cerebellar subjects, dysfunction of non-cerebellar structures cannot be excluded.

Surgical treatment of primary intracranial myxoma in a child following radiotherapy: case report and review of the literature.

INTRODUCTION: Myxomas are benign tumors of the mesenchymal origin and account for about half of the benign cardiac tumors. Occasionally, they occur at other locations, but the intracranial manifestation of a myxoma is exceptionally rare. As a secondary neoplasia following radiotherapy, myxoma has only been reported once in the literature. MATERIAL AND METHODS: A 12-year-old girl, who was previously treated for a medulloblastoma, was diagnosed with a new lesion at the left transverse sinus in the follow-up magnetic resonance imaging (MRI). Indication for surgery was made and complete removal could be achieved. RESULTS AND DISCUSSION: Histological examination revealed a myxoma. Further staging showed no other manifestation of the myxoma. The close relation to the radiation field of the posterior fossa makes it highly suggestive that the myxoma developed as a secondary neoplasia induced by radiotherapy. Treatment philosophy for this benign tumor entity is a completed resection of the lesion with regular follow-up MRI.

Aphasia, neglect and extinction are no prominent clinical signs in children and adolescents with acute surgical cerebellar lesions.

The aim of the present study was to examine if clinically significant signs of aphasia, neglect or extinction, which have a well-known cerebral lateralization, are present in children and adolescents with acute focal lesions following tumour surgery in the cerebellum. Eight children and adolescents with cerebellar tumours were tested within days after tumour surgery. None of the children had received radiation or chemotherapy at the time of testing. Eleven age- and education-matched control subjects with major orthopedic surgery participated. High-resolution magnetic resonance images showed lesions of the right cerebellar hemisphere in three and of the left hemisphere in five children. Standard aphasia tests revealed no statistically significant difference comparing children with right- and left-sided lesions and controls. Mild signs of language disturbance, however, were present in single subjects with right-sided cerebellar lesions. Neglect and extinction tasks revealed minor abnormalities, which lacked consistent lateralization and were best explained by more unspecific attentional deficits and motor disorders in acute post-surgical stage. Acute right-sided cerebellar lesions can be followed by mild signs of language disturbances in single subjects. Clinically significant signs of neglect and extinction, however, are not observed in children and adolescents with acute surgical cerebellar lesions.

Cognitive functions in patients with MR-defined chronic focal cerebellar lesions.

The aim of the present study was to examine cognitive functions in a group of chronic patients with focal cerebellar lesions. Both effects of localization (anterior vs. posterior lobe) and side (left vs. right cerebellar hemisphere) were of interest. Fourteen patients with infarctions within the territory of the posterior inferior cerebellar artery (PICA) and seven patients with infarctions within the territory of the superior cerebellar artery (SCA) participated. The affected lobules and nuclei were assessed based on 3D MR imaging. The right cerebellar hemisphere was affected in eight PICA and two SCA patients, the left hemisphere in six PICA and four SCA patients. One SCA patient revealed a bilateral lesion. In order to study possible lateralization of functions, subjects performed a language task as well as standard neglect and extinction tests. Moreover, two tests of executive functions were applied. There were no significant group differences apart from a verbal fluency task, in which all cerebellar patients - but especially those with right-sided lesions - were impaired. Voxel-based lesion-symptom mapping (VLSM) revealed that a lesion of the right hemispheric lobule Crus II was associated with impaired performance in the verbal fluency task. In sum, the results showed preserved cognitive abilities in chronic cerebellar patients apart from impairments of verbal fluency in patients with right-cerebellar lesions. The latter findings are in line with the assumption that the right posterolateral cerebellar hemisphere supports functions associated with verbal fluency.

Functional recovery of children and adolescents after cerebellar tumour resection.

This study examined whether lesions to the cerebellum obtained in early childhood are better compensated than lesions in middle childhood or adolescence. Since cerebellar lesions might affect motor as well a cognitive performance, posture, upper limb and working memory function were assessed in 22 patients after resection of a cerebellar tumour (age at surgery 1-17 years, minimum 3 years post-surgery). Working memory was only impaired in those patients who had received chemo- or radiation therapy. Postural sway was enhanced in 64% of the patients during dynamic posturography conditions, which relied heavily on vestibular input for equilibrium control. Upper limb function was generally less impaired, but 54% of the patients revealed prolonged deceleration times in an arm pointing task, which probably does not reflect a genuine cerebellar deficit but rather the patients' adopted strategy to avoid overshooting. Age at surgery, time since surgery or lesion volume were poor predictors of motor or cognitive recovery. Brain imaging analysis revealed that lesions of all eight patients with abnormal posture who did not receive chemo- and/or radiation therapy included the fastigial and interposed nuclei (NF and NI). In patients with normal posture, NI and NF were spared. In 11 out of 12 patients with abnormal deceleration time, the region with the highest overlap included the NI and NF and dorsomedial portions of the dentate nuclei in 10 out of 12 patients. We conclude that cerebellar damage inflicted at a young age is not necessarily better compensated. The lesion site is critical for motor recovery, and lesions affecting the deep cerebellar nuclei are not fully compensated at any developmental age in humans.

Behavioral and affective changes in children and adolescents with chronic cerebellar lesions.

The aim of the present study was to investigate if clinically relevant affective or behavioral changes as described in adults in the cerebellar affective syndrome by Schmahmann and Sherman [The cerebellar cognitive affective syndrome, Brain 121 (1998) 561-579] are likely to occur as a long-term sequelae of cerebellar vermis lesions in children. Site and extent of the vermal lesion were defined on the basis of individual 3D-MRI scans and lesion data were correlated with behavioral and affective changes. Affect and behavior were assessed in children after cerebellar tumor surgery by means of experimenter ratings based on the description of the cerebellar affective syndrome and free ratings by the patients and their parents. Twelve children and adolescents with a former cerebellar astrocytoma surgery without subsequent radiation or chemotherapy participated. Detailed analysis of individual 3D-MR images revealed that lesions affected the vermis in nine children. Experimenter ratings according to Schmahmann revealed no relevant problems in patients. In five out of nine patients with vermal affection somewhat increased thoughtful, anxious or aggressive behavior was reported by patients and parents. In conclusion, minor behavioral and affective changes were present in a subset of children with chronic vermal lesions.

Elastin polymorphism haplotype and intracranial aneurysms are not associated in Central Europe.

BACKGROUND AND PURPOSE: The occurrence of intracranial aneurysms and of aneurysmal subarachnoid hemorrhage are influenced by genetic factors. Recent genomic studies in Japan have defined 3 chromosomal loci and 1 haplotype of elastin polymorphisms as important risk factors, both for affected sib pairs and sporadic patients. METHODS: We have genotyped 2 single nucleotide polymorphisms in the elastin gene and evaluated their allelic association with intracranial aneurysm in a Central European sample of 30 familial and 175 sporadic patients and 235 population controls. RESULTS: We found no allelic association between this elastin polymorphism haplotype and intracranial aneurysm. CONCLUSIONS: Our data probably reflect increased genetic heterogeneity of intracranial aneurysm in Europe compared with Japan.

Clinical outcome and neuropsychological deficits after right decompressive hemicraniectomy in MCA infarction.

BACKGROUND AND PURPOSE: The purpose of this study was to analyse in detail the functional outcome and the neuropsychological deficits in patients with space-occupying infarction of the non-dominant hemisphere one year after surgery. METHODS: Postoperative complications and retrospective consent to surgery were assessed in a semi-structured interview in 26 patients. Functional outcome was measured with the Barthel-Index (BI) and Rankin-Scale. Neuropsychological tests in 14 patients focused on visuo-spatial and visuo-constructive abilities, attention, spatial span and self-rated mood. RESULTS: The one-year survival rate was 69 % (18 of 26). The functional outcome was good (BI >/= 90) in 3 patients, fairly good (BI 75-85) in 6, moderate (BI 30-70) in 6, and poor (BI 0-25) in 3 patients. Age was an independent predictor of outcome, patients above 52 years had a BI of 50 or below. Neuropsychological tests (14 of 18) showed profound attention deficits in all patients, and visuo-spatial and visuo-constructive deficits in patients with lower formal education. Retrospectively, 4 of 18 patients would not give consent to surgery again, mostly because of the bad quality of life postoperatively. CONCLUSION: Older patients do not seem to benefit from decompressive hemicraniectomy; more than half of the surviving younger patients have a good outcome and live independently. Attention deficits are prominent in all patients; visuo-spatial and constructive deficits are less pronounced in patients with higher formal education. Retrospective agreement to decompressive hemicraniectomy is high in patients with good functional outcome.

Treatment of wide-necked intracranial aneurysms with a self-expanding stent system: initial clinical experience.

BACKGROUND AND PURPOSE: Currently available stents for intracranial use usually are balloon-expandable coronary stents that carry the risk of damaging a dysplastic segment of the artery, with potential vessel rupture. We assessed the technical feasibility and efficacy of the combined application of a flexible, self-expanding neurovascular stent and detachable coils in the management of wide-necked intracranial aneurysms in humans. METHODS: Four consecutive patients with a wide-necked intracranial aneurysm were treated with a combined approach that consisted of delivery of a flexible self-expanding neurovascular stent through a microcather to cover the neck of the aneurysm and subsequent filling of the aneurysm with coils through the stent interstices. The aneurysms were located at the internal carotid artery (n=2) and the basilar tip encroaching the P1 segment (n=2). Previous attempts with conventional endosaccular coil packing alone failed in all cases. RESULTS: Stent placement in the desired position with complete or nearly complete occlusion of the aneurysms was feasible in all patients. In one patient, aneurysm perforation with the microcatheter occurred and necessitated ventricular drainage, which led to a large parenchymal and intraventricular hemorrhage because of the strong anticoagulation regimen. Six-month follow-up demonstrated no focal neurologic sequelae in any of the patients, except slight memory dysfunction in the patient with bleeding. CONCLUSION: Preliminary data demonstrate that this extremely flexible stent is technically easy to deploy and can be easily and safely maneuvered through severely tortuous vessels, enabling the treatment of intracranial wide-necked aneurysms. The combination of endovascular reconstruction of the parent vessel with use of a self-expanding stent followed by coil embolization offers a promising therapeutic alternative for wide-necked aneurysms not amenable to coil embolization alone. Although immediate angiographic results are promising, long-term angiographic and clinical follow-up is essential to determine permanent vessel patency and aneurysm occlusion rate.

Endovascular treatment of unruptured intracranial aneurysms.

BACKGROUND AND PURPOSE: Intracranial aneurysms are common, with an overall frequency ranging from 0.8% to 10%. Because prognosis after subarachnoid hemorrhage is still very poor, treatment of unruptured aneurysms, either neurosurgically or endovascularly, has been advocated. However, risk of rupture and subsequent subarachnoid hemorrhage needs to be considered against the risks of elective treatment. We analyzed the technical feasibility, safety, and efficacy of endovascular treatment of a consecutive series of unruptured cerebral aneurysms. METHODS: From July 1997 through December 2000, a total of 76 patients with 82 unruptured cerebral aneurysms were treated at our institution. Endovascular treatment was administered to 39 consecutive patients with a total of 42 unruptured cerebral aneurysms. Thirty-six aneurysms were treated with an endovascular technique; in six patients, the parent artery was occluded to eliminate aneurysmal perfusion. Aneurysms were located either in the anterior (n = 31) or posterior (n = 11) circulation. Eight patients had experienced previous subarachnoid hemorrhage from other aneurysms and were treated electively after complete rehabilitation. Ten patients had neurologic symptoms; in 21 patients, the aneurysm was an incidental finding. Eighteen aneurysms were small (0-5 mm), 11 were medium (6-10 mm), nine were large (11-25 mm), and four were giant (> 25 mm). Occlusion rate was categorized as complete (100%), subtotal (95-99%), and incomplete (< 95%) obliteration. RESULTS: Endovascular treatment was technically feasible for 38 of 42 aneurysms. Complete (100%) or nearly complete (95-99%) occlusion was achieved in 34 of 38 aneurysms. In four aneurysms of the internal carotid artery, only incomplete (< 95%) occlusion was achieved. All patients except one with mild neurologic deficits according to the Glasgow Outcome Scale and one with mild memory dysfunction but no focal neurologic deficit achieved good recovery, resulting in a morbidity rate of 4.8% and a mortality rate of 0%. CONCLUSION: Endovascular embolization of unruptured cerebral aneurysms is an effective therapeutic alternative to neurosurgical clipping and is associated with low morbidity and mortality rates. For the management of unruptured aneurysms, endovascular treatment should be considered.

Complementary management of partially occluded aneurysms by using surgical or endovascular therapy.

OBJECT: The authors present a series of patients in whom partially occluded aneurysms were retreated using complementary surgical or endovascular therapy. METHODS: During a period of 18 months, 301 patients with intracranial aneurysms were treated using either clip application (171 patients) or endovascular embolization with Guglielmi Detachable Coils ([GDCs] 130 patients). Routine posttreatment angiography studies revealed residual aneurysms in 21 of these patients, nine of whom were retreated using an endovascular or surgical method, with a mean treatment latency of 1.2 months. Four patients underwent primary surgical clip application, whereas five patients experienced GDC packing first. Among patients in the surgical group, the residual aneurysm neck was small and total elimination of the aneurysm was achieved by packing in GDCs. In patients in the endovascular group the authors incompletely packed the aneurysm because of its wide neck or fusiform component in two patients, perforation of a very small aneurysm in one patient, and coil dislocation in another patient. Typical coil compaction occurred in one case. Complete clip application was achieved in all patients. There was no complication in any patient due to the second treatment modality. Final outcome was excellent or good in six and fair in three. CONCLUSIONS: Following clip application or endovascular embolization of intracranial aneurysms, the use of complementary surgical or endovascular management is successful and associated with low morbidity.

Functional recovery and rehabilitation of postural impairment and gait ataxia in patients with acute cerebellar stroke.

Studies about recovery from cerebellar stroke are rare. The present study assessed motor deficits in the acute phase after isolated cerebellar stroke focusing on postural impairment and gait ataxia and outlines the role of lesion site on motor outcome, the course of recovery and the effect of treadmill training. 23 patients with acute and isolated cerebellar infarction participated. Deficits were quantified by ataxia scores and dynamic posturography in the acute phase and in a follow up after 2 weeks and 3 months. MRI data were obtained to correlate lesion site with motor performance. Half of the patients that gave informed consent and walked independently underwent a 2-week treadmill training with increasing velocity. In the acute phase patients showed a mild to severe ataxia with a worse performance in patients with infarction of the superior in comparison to the posterior inferior cerebellar artery. However, after 3 months differences between vascular territories were no longer significant. MRI data showed that patients with larger infarct volumes had a significantly more severe ataxia. In patients with ataxia of stance, gait and lower limbs lesions were more common in cerebellar lobules IV to VI. After 3 months a mild ataxia in lower limbs and gait, especially in gait speed persisted. Because postural impairment had fully recovered, remaining gait ataxia was likely related to incoordination of lower limbs. Treadmill training did not show significant effects. Future studies are needed to investigate whether intensive coordinative training is of benefit in patients with cerebellar stroke.