Safety Profile of Infinity Deep Brain Stimulation Electrode Placement in a 1.5T Interventional MRI Suite: Consecutive Single-Institution Case Series.

"Asleep" deep brain stimulation using general anesthesia and intraoperative MR imaging guidance is considered "off-label" use by current FDA guidelines but is widely used in neurosurgical practice, and excellent safety has been demonstrated using first-generation, omnidirectional electrodes. Safety data for second-generation, directional electrodes in the interventional MR imaging environment have not yet been published. Herein, we report 34 cases of asleep deep brain stimulation using second-generation, directional electrodes in an interventional MR imaging suite at a single institution. Procedural complications and imaging data are described. All patients underwent postoperative MR imaging with fully implanted ("internalized") electrodes after scalp closure; 4 patients also underwent MR imaging with "externalized" electrodes before scalp closure. No MR imaging-related complications were observed, and procedural complication rates were comparable to prior series. This suggests that the use of second-generation, directional electrodes in the interventional MR imaging environment appears to be safe when following manufacturer-published imaging guidelines.

Elevated mean diffusivity in the left hemisphere superior longitudinal fasciculus in autism spectrum disorders increases with more profound language impairment.

BACKGROUND AND PURPOSE: Language impairments are observed in a subset of individuals with ASD. To examine microstructural brain white matter features associated with language ability in ASD, we measured the DTI parameters of language-related white matter tracts (SLF) as well as non-language-related white matter tracts (CST) in children with ASD/+LI and ASD/-LI) and in TD. MATERIALS AND METHODS: Eighteen children with ASD/-LI (age range, 6.7-17.5 years), 17 with ASD/+LI (age range, 6.8-14.8 years), and 25 TD (age range, 6.5-18 years) were evaluated with DTI and tractography. Primary DTI parameters considered for analysis were MD and FA. RESULTS: There was a main effect of diagnostic group on age-corrected MD (P < .05) with ASD/+LI significantly elevated compared with TD. This was most pronounced for left hemisphere SLF fiber tracts and for the temporal portion of the SLF. There was significant negative correlation between left hemisphere SLF MD values and the clinical assessment of language ability. There was no main effect of diagnostic group or diagnostic group X hemisphere interaction for FA. Although there was a main effect of diagnostic group on values of MD in the CST, this did not survive hemispheric subanalysis. CONCLUSIONS: Abnormal DTI parameters (specifically significantly elevated MD values in ASD) of the SLF appear to be associated with language impairment in ASD. These elevations are particularly pronounced in the left cerebral hemisphere, in the temporal portion of the SLF, and in children with clinical language impairment.

Diffusion tensor imaging in children with periventricular leukomalacia: variability of injuries to white matter tracts.

BACKGROUND AND PURPOSE: Conventional MR imaging shows evidence of brain injury and/or maldevelopment in 70%-90% of children with cerebral palsy (CP), though its capability to identify specific white matter tract injury is limited. The great variability of white matter lesions in CP already demonstrated by postmortem studies is thought to be one of the reasons why response to treatment is so variable. Our hypothesis is that diffusion tensor imaging (DTI) is a suitable technique to provide in vivo characterization of specific white matter tract lesions in children with CP associated with periventricular leukomalacia (PVL). MATERIALS AND METHODS: In this study, 24 children with CP associated with PVL and 35 healthy controls were evaluated with DTI. Criteria for identification of 26 white matter tracts on the basis of 2D DTI color-coded maps were established, and a qualitative scoring system, based on visual inspection of the tracts in comparison with age-matched controls, was used to grade the severity of abnormalities. An ordinal grading system (0=normal, 1=abnormal, 2=severely abnormal or absent) was used to score each white matter tract. RESULTS: There was marked variability in white matter injury pattern in patients with PVL, with the most frequent injury to the retrolenticular part of the internal capsule, posterior thalamic radiation, superior corona radiata, and commissural fibers. CONCLUSION: DTI is a suitable technique for in vivo assessment of specific white matter lesions in patients with PVL and, thus, a potentially valuable diagnostic tool. The tract-specific evaluation revealed a family of tracts that are highly susceptible in PVL, important information that can potentially be used to tailor treatment options in the future.

DOPA-sensitive progressive dystonia of childhood with diurnal fluctuations of symptoms: a case report.

Progressive dystonia with diurnal fluctuations sensitive to levodopa, also known as Segawa's disease, is a rare form of autosomal dominant extrapyramidal disease in the pediatric age group. The dystonic and Parkinson-like symptoms are the main clinical features of the disease and, characteristically but not in all cases, show a diurnal variation. They are absent or present to a lesser extent in the morning, worsening during the day. Treatment with small doses of levodopa results in remission or marked improvement of the symptomatology. We present the case of a 11 years old female patient that developed a dystonic posture in her feet that led her to a tip-toe walking pattern, since the age of 2. Diurnal fluctuations of the symptomatology were noticed by her mother. At 7 years of age she developed a left deviation of the head and an abnormal flexor posture of the left arm. In the next years the symptoms progressed and the fluctuations became less evident. At the age of 10, they were present soon after she woke up in the morning. The neurological examination disclosed a dystonic posturing of the head and left arm, a generalized rigidity of the extremities and a palpebral tremor. Laboratory examinations, including copper and ceruloplasmin, and neuro-imaging studies were negative. She was started on levodopa 150 mg/day with prompt disappearance of the symptomatology. After one-year follow-up she is symptom-free with only 100 mg/day of levodopa. No adverse effect was observed so far.