Surgical Management of Thoracic Dorsal Arachnoid Webs: A 10-Year Single-Institution Experience.

Objective: Thoracic dorsal arachnoid webs are intradural membranes that may cause obstruction of cerebrospinal fluid flow and spinal cord compression. Although well recognized, they are rare and there is a paucity of long-term data on their natural history and prognosis. We reviewed radiographic features, surgical indications, and pathologic specimens of patients diagnosed with focal thoracic dorsal arachnoid webs.

Ventricular Catheter Tract Hemorrhage as a Risk Factor for Ventriculostomy-Related Infection.

Background: Ventriculostomy-related infection (VRI) is a feared complication of external ventricular drain (EVD) placement. Although many contributing factors to VRI have been examined, little is known whether there is an association between ventriculostomy-related catheter tract hemorrhage (VCTH) and VRI.

Objective: To evaluate risk factors for VRI and assess possible correlations with VCTH.

Patterns of Health Care Costs Due to External Ventricular Drain Infections.

Background: External ventricular drain (EVD) infections are a significant cause of morbidity among neurosurgical patients and have been correlated with increased length of hospital stay and longer requirements for intensive care. To date, no studies have examined the financial impact of EVD infections.

Methods: Patients who underwent EVD placement between December 2010 and January 2016 were included in the study.

Neuronal responses to tactile stimuli and tactile sensations evoked by microstimulation in the human thalamic principal somatic sensory nucleus (ventral caudal).

The normal organization and plasticity of the cutaneous core of the thalamic principal somatosensory nucleus (ventral caudal, Vc) have been studied by single-neuron recordings and microstimulation in patients undergoing awake stereotactic operations for essential tremor (ET) without apparent somatic sensory abnormality and in patients with dystonia or chronic pain secondary to major nervous system injury. In patients with ET, most Vc neurons responded to one of the four stimuli, each of which optimally activates one mechanoreceptor type. Sensations evoked by microstimulation were similar to those evoked by the optimal stimulus only among rapidly adapting neurons.

Progressive visual loss following rupture of an intracranial dermoid cyst.

A 51-year-old man with several months of headache and progressive visual decline was found to have bilateral optic disc pallor with significant impairment of visual acuity. Despite a thorough ophthalmologic evaluation, the cause of visual loss could not be elucidated. MRI of the brain revealed a lesion in the left anterior Sylvian fissure as well as disseminated foci of subarachnoid fat consistent with a diagnosis of a ruptured dermoid cyst.

Complete calvarial agenesis in conjunction with a Tessier 1-13 facial cleft.

Amniotic band sequence (ABS) is a condition in which rupture of the amniotic sac leads to the development of a broad spectrum of fetal anomalies. A newborn male presented at term with multiple craniofacial and skeletal anomalies, including attachment of the placenta to the head, a paramedian facial cleft, and multiple skeletal anomalies. The patient has undergone several operations to date.

Arachnoiditis ossificans.

Objective: Arachnoiditis ossificans is an uncommon clinical entity in which arachnoid ossification leads to clinical symptomatology. In this case report, we describe the case of a myelopathic patient with arachnoid ossifications, an arachnoid cyst, and syringomyelia coexisting with a herniated thoracic disc at the same levels.

Case Description: An 81-year-old woman presented with rapidly progressive leg weakness, dysesthetic pains, and urinary incontinence.

Demonstration of motor imagery movement and phantom movement-related neuronal activity in human thalamus.

Functional imaging studies show that motor imagery activates multiple structures in the human forebrain. We now show that phantom movements in an amputee and imagined movements in intact individuals elicit responses from neurons in several human thalamic nuclei. These include the somatic sensory nucleus receiving input from the periphery (ventral caudal), and the motor nuclei receiving input from the cerebellum [ventral intermediate (Vim)] and the basal ganglia [ventral oral posterior (Vop)].

Vertebral synovial chondromatosis. Report of two cases and review of the literature.

Synovial chondromatosis is an uncommon disorder characterized by the formation of multiple cartilaginous nodules within the synovium, most commonly affecting large joints. Its involvement with the spine is rare; only six cases have been reported. The authors describe two patients with synovial chondromatosis involving the cervical spine.

Attention to pain is processed at multiple cortical sites in man.

Painful cutaneous laser stimuli evoked potentials (LEPs) were recorded over the primary somatosensory (SI), parasylvian, and medial frontal (MF) cortex areas in a patient with subdural electrode grids located over these areas for surgical treatment of epilepsy. The amplitudes of the negative (N2*) and positive (P2**) LEP peaks over SI, parasylvian, and MF cortex were enhanced by attention to (counting stimuli), in comparison with distraction from the stimulus (reading for comprehension). Late positive deflections following the P2** peak (late potential-LP) were recorded over MF and from the lateral premotor regions during attention but not during distraction.

E-mail consultation: clinical, financial, legal, and ethical implications.

Background: Communication via e-mail has become widespread. Nearly every practicing neurosurgeon is confronted with numerous unsolicited e-mail requests for medical advice, guidance, or information. Neurosurgeons need to be aware of the clinical, financial, legal, and ethical implications of providing medical consultation via e-mail.

Microstimulation in the region of the human thalamic principal somatic sensory nucleus evokes sensations like those of mechanical stimulation and movement.

We explored the region of human thalamic somatic sensory nucleus (ventral caudal, Vc), corresponding to monkey ventral posterior (VP), with threshold microstimulation (TMIS) during stereotactic procedures for the treatment of tremor. Of 122 sites in 116 patients (124 thalami) where mechanical (touch, pressure, and sharp) or movement [movement through the body (movement) and vibration] sensations were evoked, 72 sites were found in the core or in adjacent regions, posterior-inferior (33), inferior (4), and posterior to the core (13). Sites where TMIS evoked touch were less frequently found in the core than those where movement or pressure sensations were evoked.

Attenuation of cerebellar tremor with implantation of an intrathecal baclofen pump: the role of gamma-aminobutyric acidergic pathways. Case report.

The authors present the case of a 49-year-old woman with disabling bilateral upper-extremity cerebellar tremor that resolved unexpectedly after placement of an intrathecal baclofen pump for lower-extremity spasticity. The tremor amplitude decreased nearly linearly with increasing intrathecal baclofen dosage, and disappeared completely at a dose of 250 microg/day. In this report the authors demonstrate the role of the gamma-aminobutyric acidergic system in the pathogenesis of cerebellar tremor, and these findings may lead to a new treatment modality for patients disabled by this manifestation of their disease.

Talc pleurodesis mimics pleural metastases: differentiation with positron emission tomography/computed tomography.

Talc pleurodesis is a technique used in the treatment of patients with persistent pleural effusions or pneumothorax not amenable to other treatment. These are commonly seen in patients with malignant thoracic neoplasms. Radiographic abnormalities resulting from prior talc pleurodesis could be confused with progression of the underlying neoplastic process.