Transcranial alternating current stimulation reduces symptoms in intractable idiopathic cervical dystonia: a case study.

Idiopathic cervical dystonia (ICD) is a movement disorder often resulting in profound disability and pain. Treatment options include oral medications or other invasive procedures, whereas intractable ICD has been shown to respond to invasive (deep) brain stimulation. In the present blinded, placebo-controlled case study, transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS) has been applied to a 54-year old patient with intractable ICD. Results showed that 15 Hz tACS had both immediate and cumulative effects in dystonic symptom reduction, with a 54% reduction in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total score, and a 75% in the TWSTRS Pain Scale. These effects were persistent at 30-days follow-up. This is the first report to demonstrate a significant and lasting therapeutic effect of non-invasive electrical brain stimulation in dystonia.

Serum levels of S-100B after recreational scuba diving.

Recreational scuba diving is a sport of increasing popularity. Previous studies indicating subtle brain injury in asymptomatic divers imply a cumulative effect of minor neural insults in association with diving for professional and/or recreational purposes, over the long-term. This is the first study to investigate putative neural tissue burden during recreational scuba diving by measuring circulating levels of S-100B, a sensitive biomarker of brain injury. 5 male divers performed 3 consecutive dives under conservative recreational diving settings (maximum depth 15 m, duration of dive 56 min, ascend rate 1.15 m/min) with an interval of 12 h between each session. Although a small increase in serum S-100B levels after each dive was apparent, this increase did not quite reach statistical significance (p=0.057). Moreover, no abnormal S-100B values were recorded (mean baseline: 0.06 µg/L, mean post-dive: 0.086 µg/L) and no effect of the 3 consecutive dives on changes in S-100B levels was detected. These results suggest that under the experimental conditions tested, diving does not seem to have a discernible and/or cumulative impact on central nervous system integrity. The extent to which variable diving settings and practices as well as individual susceptibility factors underlie putative neural tissue burden in asymptomatic divers, remains to be established.

Current concepts on the mechanisms of dystonia and the beneficial effects of deep brain stimulation.

The application of lesioning procedures in the basal ganglia and, more recently, of deep brain stimulation (DBS) has revolutionalized dystonia treatment. However, our understanding of the mechanism of action of DBS is only minimal. This is largely due to a rudimentary understanding of dystonia pathophysiology itself, which in turn reflects an insufficient understanding of the functional significance of the cortico-striato-pallido-thalamocortical loops. The initial dystonia pathophysiology concept was one of changes in oscillation rate. Soon, it was realized that not only rate but also the pattern of basal ganglia activity is crucial in the etiology of the disease. The observations of altered somatosensory responsiveness and cortical neuroplasticity, along with the vast array of clinical phenotypes, imply the need for a wholistic neuronal pathophysiology model; one in which an underlying defect of basal ganglia function results in increased cortical excitability, misprocessing of sensory feedback, aberrant cortical plasticity, and ultimately clinical dystonia. This unified dystonia pathophysiology model, although simplistic, may provide the scaffold on which all incoming research and clinical data becomes united in a meaningful and practical way. In light of this model, the dramatic response of some forms of dystonia to pallidal stimulation, the time latency for the beneficial effect and even the presence of non-responders may be explained. Additionally, it may help in developing a rationale for more efficacious DBS programming, better selection of the timing of surgery, and more successful identification of those candidates that are most likely to respond to DBS.

Primary extracerebral meningeal glioblastoma: clinical and pathological analysis.

Primary meningeal gliomas are uncommon tumors in the subarachnoid space, their primary characteristic being the absence of any obvious connection to the brain parenchyma. Rarely, they are quite malignant and assume a bulky, well circumscribed appearance rendering the differential diagnosis from other CNS neoplasms difficult. A 53-year-old man presented with a history of persistent headaches and left sided weakness. Magnetic resonance imaging revealed a temporoparietal mass attached to the dura that strongly resembled a meningioma. At surgery, the outer layer of the dura mater was intact and there was a clear brain-tumor interface without obvious pial disruption. Histological examination showed a biphasic pattern consisting of benign connective tissue intermingled with bundles of what seemed to be a glioblastoma. The mass demonstrated strong positivity for GFAP and the MIB labeling index focally exceeded 20%. The tumor was identified as a primary meningeal glioblastoma. The patient was disease-free for 42 months, after which he developed a recurrence for which he was re-operated. This time, the pathological findings of the tumor were those of a typical glioblastoma multiforme. We discuss the origin of the initial neoplasm and also the differential diagnosis that needs to include meningioma, aggressive glioblastoma infiltrating the dura and a recently recognized bimorphic CNS tumor: the desmoplastic glioblastoma.

Trigonal cavernous angioma: a short illustrated review.

PURPOSE: Intraventricular cavernomas are rare. Even more rare are those presenting in the trigone of the lateral ventricles. METHODS: We performed a search of the literature of the last 30 years and identified all cases of intraventricular cavernous angiomas. Trigonal cavernomas were separately identified and analysed. Our search yielded a total of 13 trigonal cavernomas. RESULTS: Of a total of 61 intraventricular cases, 13 were located in the trigone of the lateral ventricles. The most prominent presenting symptom was intracranial hypertension (68.9%), followed by seizures (18.2%) and hemorrhage (13.1%).The literature review revealed a trend of intraventricular cavernomas to present with intracranial hypertension rather than seizures or focal neurologic deficit, unlike their intraparenchymal counterparts. We feel that this difference has received little attention in the international literature. We discuss a possible pathogenetic mechanism for the presence of intracranial hypertension and address different aspects of diagnosis and treatment of this benign lesion. CONCLUSIONS: Trigonal cavernomas are benign lesions that have an excellent outcome after radical excision. Symptoms and signs of intracranial hypertension and hydrocephalus may be the prominent initial presentation of this rare ailment.

Cervical disc, mimicking nerve sheath tumor, with rapid spontaneous recovery: a case report.

The study design includes a case report and clinical discussion. The potential of acute disc herniations to regress spontaneously has been previously reported. However, the initial radiological presentation can be misleading, leading to therapeutic pitfalls, especially when the presence of myelopathy calls for early intervention. We present the case of a 46-year-old woman with a cervical intraspinal enhancing mass, associated enhancement of the C6 root and myelopathy, leading to the presumptive diagnosis of a nerve sheath tumor. The patient was offered surgery, which she denied. The patient returned 7 weeks later with significant clinical improvement. A subsequent magnetic resonance imaging depicted a herniated cervical disc and regression of myelopathy. Although spontaneous regression of disc prolapse and myelopathy have been previously reported, the initial radiological presentation and the short period of regression in this case highlight the need for a thorough understanding of the natural course of cervical disc herniations. Nonsurgical conservative observation should be considered an option for treatment for some cervical disc herniations that are likely to regress for very specific and predictable reasons.

Intracranial hemorrhagic arachnoid cyst: the role of diffusion-weighted imaging.

The majority of hemorrhagic arachnoid cysts are correlated with trauma or aneurysmal rupture. We report on a 35-year-old woman with acute headache and an intracranial mass lesion that was hyperdense in CT and hyperintense in conventional MRI images. The history and imaging were negative for trauma or vascular anomaly. Diffusion-weighted imaging (DWI) clearly demonstrated a large right anterior and middle cranial fossa arachnoid cyst with associated subacute intracystic hemorrhage without subdural hematoma. DWI offers invaluable information for the differential diagnosis of hemorrhagic arachnoid cysts from other extra-axial space-occupying lesions.