Motor cortex plasticity predicts recovery in acute stroke

Repetitive transcranial magnetic stimulation of the brain given as intermittent theta burst stimulation (iTBS) can induce long-term potentiation (LTP)-like changes in the stimulated hemisphere and long-term depression (LTD)-like changes in the opposite hemisphere. We evaluated whether LTP- and LTD-like changes produced by iTBS in acute stroke correlate with outcome at 6 months. We evaluated the excitability of affected hemisphere (AH) and unaffected hemisphere (UH) by measuring motor threshold and motor-evoked potential (MEP) amplitude under baseline conditions and after iTBS of AH in 17 patients with acute ischemic stroke. Baseline amplitude of MEPs elicited from AH was significantly smaller than that of MEPs elicited from UH, and baseline motor threshold was higher for the AH. Higher baseline MEP values in UH correlated with poor prognosis. iTBS produced a significant increase in MEP amplitude for AH that was significantly correlated with recovery. A nonsignificant decrease in MEP amplitude was observed for the UH. When the decrease in the amplitude of UH MEPs was added to the regression model, the correlation was even higher. Functional recovery is directly correlated with LTP-like changes in AH and LTD-like changes in UH and inversely correlated with the baseline excitability of UH.

Opioid-dopaminergic interactions in primary empty sella

Previous studies have indicated different abnormalities of PRL secretion in patients with primary empty sella (PES). Since it is known that endogenous opiates and dopamine interact in modulating PRL secretion, we have studied the effect of an opiate receptor blockade (with Naloxone, NAL, 1.6 mg/h as a continuous infusion) on anterior pituitary hormones and on PRL responsiveness to metoclopramide (MCP), in 10 premenopausal normoprolactinemic patients with PES, studied in follicular phase, in order to investigate neurotransmitter abnormalities present in such a syndrome. NAL failed to significantly affect LH and FSH basal levels; on the contrary, slight but significant increases in PRL and GH secretion were observed. NAL partially blunted the PRL responsiveness to the dopaminergic blockade, which was very marked when tested after MCP alone. These data confirm that the modulation of anterior pituitary hormone secretion is different in PES patients, when compared with normal subjects. The infusion of NAL induced a "paradoxical" increase in hormones (PRL and GH) which are normally stimulated by endogenous opiates; but, on the other side, it blocked the marked PRL responsiveness to the dopaminergic blockade, which is characteristic of PES syndrome. This phenomenon seems to indicate that the relationships between dopaminergic and opiatergic neurons could be modified by the neuroanatomic alteration which is present in this complex syndrome.

Camptocormia in Parkinson disease: an epidemiological and clinical study

BACKGROUND

Camptocormia is an abnormal flexion of the thoracolumbar spine during standing and walking that abates in the recumbent position.

METHODS

In a single-centre epidemiological and clinical study, the prevalence of camptocormia in Parkinson disease (PD) and its relationship with the clinical features of PD were investigated. A total of 275 consecutive outpatients were systematically screened for camptocormia with a clinical evaluation. Patients who screened positive for camptocormia were subsequently reassessed by formal goniometric analysis. The demographic and clinical features of the patients with and without camptocormia were then compared.

RESULTS

A 6.9% (19/275, 95% CI, 4.2 to 10.6) prevalence of camptocormia was found. Camptocormia was found in patients with more severe PD, as clinically assessed by the Hoehn-Yahr (HY) staging and the motor Unified Parkinson Disease Rating Scale (UPDRS) part III, longer l-dopa treatment duration and greater l-dopa daily dose and presence of DSM-IV dementia. Camptocormia was reported to develop after the clinical onset of PD. No correlation was found between the degree of trunk flexion and age, duration of PD, UPDRS motor score, HY staging, and l-dopa treatment duration and dose. As a risk factor, the study identified previous vertebral surgery.

CONCLUSIONS

Camptocormia, a relatively common sign in PD seems to be related to the clinical severity of PD.

Contrast-enhanced MR imaging of brain lesions: a large-scale intraindividual crossover comparison of gadobenate dimeglumine versus gadodiamide

BACKGROUND AND PURPOSE

The higher relaxivity of gadobenate dimeglumine compared with gadodiamide is potentially advantageous for contrast-enhanced brain MR imaging. This study intraindividually compared 0.1-mmol/kg doses of these agents for qualitative and quantitative lesion enhancement.

MATERIALS AND METHODS

Adult patients with suggested or known brain lesions underwent 2 identical MR imaging examinations at 1.5T, one with gadobenate dimeglumine and the other with gadodiamide. The agents were administered in randomized order separated by 3-14 days. Imaging sequences and postinjection acquisition timing were identical for the 2 examinations. Three blinded readers evaluated images qualitatively for diagnostic information (lesion extent, delineation, morphology, enhancement, and global preference) and quantitatively for contrast-to-noise ratio (CNR).

RESULTS

One hundred thirteen of 138 enrolled patients successfully underwent both examinations. Final diagnoses were intra-axial tumor, metastasis, extra-axial tumor, or other (47, 27, 18, and 21 subjects, respectively). Readers 1, 2, and 3 demonstrated global preference for gadobenate dimeglumine in 63 (55.8%), 77 (68.1%), and 73 (64.6%) patients, respectively, compared with 3, 2, and 3 patients for gadodiamide (P < .0001, all readers). Highly significant (P < .0001, all readers) preference for gadobenate dimeglumine was demonstrated for all qualitative end points and for CNR (increases of 23.3%-34.7% and 42.4%-48.9% [spin-echo and gradient-refocused echo sequences, respectively] for gadobenate dimeglumine compared with gadodiamide). Inter-reader agreement was good for all evaluations (kappa = 0.47-0.69). Significant preference for gadobenate dimeglumine was demonstrated for all lesion subgroup analyses.

CONCLUSION

Significantly greater diagnostic information and lesion enhancement are achieved on brain MR imaging with 0.1-mmol/kg gadobenate dimeglumine compared with gadodiamide at an equivalent dose.

Second consensus statement on the diagnosis of multiple system atrophy

BACKGROUND

A consensus conference on multiple system atrophy (MSA) in 1998 established criteria for diagnosis that have been accepted widely. Since then, clinical, laboratory, neuropathologic, and imaging studies have advanced the field, requiring a fresh evaluation of diagnostic criteria. We held a second consensus conference in 2007 and present the results here.

METHODS

Experts in the clinical, neuropathologic, and imaging aspects of MSA were invited to participate in a 2-day consensus conference. Participants were divided into five groups, consisting of specialists in the parkinsonian, cerebellar, autonomic, neuropathologic, and imaging aspects of the disorder. Each group independently wrote diagnostic criteria for its area of expertise in advance of the meeting. These criteria were discussed and reconciled during the meeting using consensus methodology.

RESULTS

The new criteria retain the diagnostic categories of MSA with predominant parkinsonism and MSA with predominant cerebellar ataxia to designate the predominant motor features and also retain the designations of definite, probable, and possible MSA. Definite MSA requires neuropathologic demonstration of CNS alpha-synuclein-positive glial cytoplasmic inclusions with neurodegenerative changes in striatonigral or olivopontocerebellar structures. Probable MSA requires a sporadic, progressive adult-onset disorder including rigorously defined autonomic failure and poorly levodopa-responsive parkinsonism or cerebellar ataxia. Possible MSA requires a sporadic, progressive adult-onset disease including parkinsonism or cerebellar ataxia and at least one feature suggesting autonomic dysfunction plus one other feature that may be a clinical or a neuroimaging abnormality.

CONCLUSIONS

These new criteria have simplified the previous criteria, have incorporated current knowledge, and are expected to enhance future assessments of the disease.

Morphological and functional MR imaging of Lhermitte-Duclos disease with pathology correlate

Lhermitte-Duclos disease (LDD) is a rare benign lesion of uncertain pathogenesis characterised by distortion of the normal cerebellar laminar cytoarchitecture. We report a case of LDD thoroughly characterized by advanced magnetic resonance imaging techniques, with diffusion-weighted, perfusion-weighted and post-gadolinium sequences. Imaging showed restricted diffusion consistent with high cellularity, high degree of vascularity and preserved blood-brain barrier permeability, correlating with pathology.

Autonomic cardiovascular function and baroreflex sensitivity in patients with cervical dystonia receiving treatment with botulinum toxin type A

OBJECTIVE

To investigate possible changes in autonomic cardiovascular regulation and cardiopulmonary baroreflex sensitivity in patients with primary cervical dystonia receiving chronic treatment with botulinum toxin type A.

METHODS

Short-term power spectral analysis of heart rate and systolic blood pressure variability, high-frequency and low-frequency oscillations of heart rate variability, low frequency/high frequency ratio and baroreflex sensitivity (alpha index) were measured in 12 patients with cervical dystonia before and 2-4 weeks after botulinum toxin type A injection and compared with normative data.

RESULTS

Before treatment, at rest, patients had significantly lower high frequency power than healthy subjects (p < 0.01), whereas no differences were found in low frequency power. Botulinum toxin injection in patients induced no changes in either power frequency. In patients before treatment and healthy subjects the low frequency oscillatory components increased similarly from rest to tilt (p < 0.01), but tilt induced lower low frequency values in patients than in healthy subjects (p < 0.01). In patients before treatment, the high frequency variations from rest to tilt remained unchanged, whereas in healthy subjects they decreased significantly (p < 0.01). Botulinum toxin type A injection in patients induced no changes in low frequency or high frequency powers. In patients before treatment the low frequency/high frequency ratio increased slightly from rest to tilt, but in healthy subjects increased significantly (p < 0.01). Botulinum toxin type A left the pretreatment low frequency/high frequency ratio unchanged. The alpha-index measured at rest in patients before treatment was lower than in healthy subjects (p<0.05), whereas during tilt was similar in both groups. The alpha-index measured after botulinum toxin injection in patients remained unchanged at rest and during tilt.

CONCLUSIONS

Patients with cervical dystonia receiving treatment with botulinum toxin type A have mild, subclinical abnormalities in autonomic cardiovascular regulation and cardiopulmonary baroreflex sensitivity. These changes do not worsen after acute botulinum toxin type A injection.

Long-term assessment of the risk of spread in primary late-onset focal dystonia

BACKGROUND

Primary late-onset focal dystonias may spread over time to adjacent body regions, but differences in the risk of spread over time among the various focal forms and the influence of age at dystonia onset on the risk of spread are not well established.

METHODS

Patients presenting with primary late-onset focal blepharospasm (BSP, n = 124), cervical dystonia (CD, n = 73) and focal hand dystonia (FHD, n = 24) with 10 years or more of disease duration (mean +/- SD, 15.3 (SD 4.9) years) were included in the study. The relationship between demographic/clinical variables and spread of dystonia was assessed by Kaplan-Meier survival curves and Cox proportional hazard regression models.

RESULTS

Patients starting with BSP, CD and FHD had similar age, sex and disease duration. Age at dystonia onset, age at initial spread and the risk of initial spread were significantly higher, whereas time elapsing from onset to initial spread was significantly lower in the BSP group than in those with onset in the neck or in the upper extremities. Conversely, these parameters were similar in the CD and FHD groups. The greater risk of spread in the BSP group was mainly evident in the first 5 years of history; thereafter, it declined and became similar to that of patients with CD/FHD. The difference in the risk of initial spread by site of onset was partly confounded by age at dystonia onset. Site of and age at dystonia onset, and age at first spread, were not significant predictors of the risk of a second spread.

CONCLUSION

This study adds new insights into the phenomenon of spread of primary late-onset focal dystonia and provides the framework for future studies aimed at an indepth investigation of the mechanism(s) of spread.

Seizure semiology of lesional frontal lobe epilepsies in children

The aim of the study was to analyse the semiology of seizures in children with frontal lobe epilepsy (FLE) and to compare them with other paediatric cohorts described in the literature as well as with adult counterparts. We analysed 174 registered seizures of 18 cases under 12 years with lesional epilepsy whose frontal origin was defined by the concordance of neuroimaging and ictal electrographic findings, and confirmed by surgery in the six cases operated on. Seizures were generally short, with a high daily frequency and usually related to sleep. The most characteristic semiological pattern consisted of complex motor seizures, particularly hypermotor. Often seizures corresponded to a mixture of different semiological patterns (tonic, gelastic, automotor, hypermotor, versive) presenting in the same seizure, often as a unique type in the same patient. With regard to several aspects the semiology of FLE in our cohort looks like that reported in adult series, in particular as to the frequency of complex motor seizures. However, our cohort was also characterised by a more protean array of seizure semiology, stressing the occurrence of seizures typically present in adults (versive and complex motor) and of some seizure patterns more characteristic in children such as epileptic spasms; moreover, the rare occurrence of secondarily generalised tonic clonic seizures (SGTCS) was confirmed.

New morphologic variants of the hand motor cortex as seen with MR imaging in a large study population

BACKGROUND AND PURPOSE

The hand motor cortex (HMC) has been classically described as having an omega or epsilon shape in axial-plane images obtained with CT and MR imaging. The aim of this study was to use MR imaging and Talairach normalization in a large sample population that was homogeneous for age and handedness to evaluate in a sex model a new classification with 5 morphologic variants of the HMC in the axial plane (omega, medially asymmetric epsilon, epsilon, laterally asymmetric epsilon, and null).

MATERIALS AND METHODS

Structural brain MR images were obtained from 257 right-handed healthy subjects (143 men and 114 women; mean age, 23.1 +/- 1.1 years) via a Talairach space transformed 3D magnetization-prepared rapid acquisition of gradient echo sequence. The frequencies of the different HMC variants were reported for hemisphere and sex.

RESULTS

The new variants of the HMC (medially asymmetric epsilon, laterally asymmetric epsilon, and null) were observed in 2.9%, 7.0%, and 1.8% of the hemispheres, respectively. Statistically significant sex differences were observed: The epsilon variant was twice as frequent in men, and an interhemispheric concordance for morphologic variants was observed only for women.

CONCLUSION

The large study population permitted the description of a new morphologic classification that included 3 new variants of the HMC. This new morphologic classification should facilitate the identification of the precentral gyrus in subsequent studies and in everyday practice.

3D rotational angiography for the diagnosis and preoperative assessment of intracranial aneurysms: preliminary experience

PURPOSE

The aim of this study was to assess the value of the systematic use of 3D rotational angiography (3DRA) in the diagnosis and preoperative evaluation of cerebral aneurysms with a view to planning endovascular embolisation.

MATERIALS AND METHODS

Thirty-five consecutive aneurysms (20 incidental and 15 after subarachnoid haemorrhage) were studied and treated by means of 3DRA over a 1-year period. All rotational studies were conducted by selective cannulation of the vessel supplying the lesion (internal carotid artery or vertebral artery) with a single injection of 20 cc of contrast agent after diagnostic angiography in anterior-posterior (AP) and laterolateral (LL) views. Three-dimensional reconstructions were generated within a mean time of 5 min, and coil embolisation was performed on the basis of the 3D images.

RESULTS

Three-dimensional RA enabled accurate definition of site, orientation, morphology and size of the sac and its relationship with the parent arteries and helped us choose the most appropriate angulation of the C-arm for guiding and controlling the embolisation procedure. Furthermore, the technique allowed us to detect six aneurysms for which conventional imaging had yielded equivocal results.

CONCLUSIONS

Based on our experience before RA equipment became available and in agreement with the literature, we believe that 3DRA improves the identification of all lesions and helps refine the choice of the most suitable embolisation material and technique. Three-dimensional RA requires substantially fewer projections and thus reduces radiation dose and volume of contrast material to the patient. The use of 3DRA most likely results in a shorter procedure time and fewer risks and complications for the patient.