Elliott Friedman

Analysis of gene expression with cDNA microarrays in rat brain after 7 and 42 days of oral lithium administration.

The gene expression profile in rat brain was examined using microarrays in rats fed lithium chloride for 7 days (subacute) or 42 days (chronic). Brain lithium concentrations were 0.39 mM and 0.79 mM (therapeutically relevant), at 7 and 42 days, respectively. Of the 4132 genes represented in the microarrays, 25 genes were downregulated by at least twofold and none was upregulated after 7 days of treatment. Expression of 50 genes was downregulated by at least two-fold at 42 days, without any being upregulated. Lithium treatment for 7 days did not affect at a measurable extent expression of 37 of the 50 genes that were downregulated at 42 days. Genes whose expression was changed at 42 days coded for a number of receptors, protein kinases, transcription and translation factors, markers of energy metabolism, and signal transduction. Thus, chronic lithium at a therapeutically relevant concentration reduced expression of a large number of genes involved in multiple signaling and other pathways, without increasing expression at a comparable extent.

Stereotactic laser ablation of epileptogenic periventricular nodular heterotopia

Periventricular nodular heterotopia (PVNH) is a neuronal migrational disorder often associated with pharmacoresistant epilepsy (PRE). Resective surgery for PVNH is limited by its deep location, and the overlying eloquent cortex or white matter. Stereotactic MR guided laser interstitial thermal therapy (MRgLITT) has recently become available for controlled focal ablation, enabling us to target these lesions. We here demonstrate the novel application and techniques for the use of MRgLITT in the management of PVNH epilepsy. Comprehensive presurgical evaluation, including intracranial EEG monitoring in two patients revealed the PVNH to be crucially involved in their PRE. We used MRgLITT to maximally ablate the PVNH in both cases. In the first case, seizure medication adjustment coupled with PVNH ablation, and in the second, PVNH ablation in addition to temporal lobectomy rendered the patient seizure free. A transient visual deficit occurred following ablation in the second patient. MRgLITT is a promising minimally invasive technique for ablation of epileptogenic PVNH, a disease not generally viewed as surgically treatable epilepsy. We also show here the feasibility of applying this technique through multiple trajectories and to create lesions of complex shapes. The broad applicability and long term efficacy of MRgLITT need to be elaborated further.

Imaging of Pediatric Neck Masses

Palpable neck masses are a common indication for pediatric imaging. Such lesions may be caused by infectious, inflammatory, tumoral, traumatic, lymphovascular, immunologic, or congenital etiologies. Radiological assessment of neck masses in young children should be tailored based on patient presentation and physical examination, as well as clinical suspicion. The goal of imaging should be to help arrive at a diagnosis or limited differential in an efficient manner while minimizing radiation exposure.

Pitfalls in the staging of cancer of the major salivary gland neoplasms.

The major salivary glands consist of the parotid, submandibular, and sublingual glands. Most neoplasms in other subsites in the head and neck are squamous cell carcinoma, but tumors of the salivary glands may be benign or malignant. Surgical treatment differs if the lesion is benign, and therefore preoperative fine needle aspiration is important in salivary neoplasms. The role of imaging is to attempt to determine histology, predict likelihood of a lesion being malignant, and report an imaging stage. This article reviews the various histologies, imaging features, and staging of major salivary gland neoplasms.

Innominate Artery Compression of the Trachea: An Unusual Cause of Apnea in a 12-Year-Old Boy

Innominate artery compression of the trachea is a common cause of airway obstruction in infants and young children. The clinical significance of this lesion, even when compression is documented endoscopically or radiographically, is controversial. Obstructive respiratory symptoms occur in only a fraction of such cases, and symptomatic patients are most commonly detected in the first year of life. We present a case of a 12-year-old boy with a chief complaint of progressive stridor and apnea who was diagnosed with symptomatic innominate artery compression of the trachea. We reviewed the literature regarding the pathology, diagnosis, and treatment of this condition.

Epilepsy imaging in adults: getting it right.

OBJECTIVE The purpose of this article is to describe an MRI protocol optimized for epilepsy evaluation, common causes of epilepsy visualized on MR images of patients evaluated for medically intractable partial epilepsy, and the basic concepts of advanced imaging techniques in the evaluation of epilepsy. CONCLUSION Epilepsy is one of the most common neurologic disorders in the United States. The long-term seizure-free success of epilepsy surgery is related to the ability to define and completely resect the epileptogenic zone. Detection of structural lesions at preoperative imaging requires not only a dedicated epilepsy protocol but also meticulous examination of the images by the interpreting radiologist with particular attention to subtle abnormalities that might otherwise go unreported.

TSC2 c.1864C>T variant associated with mild cases of tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited disorder with variable expressivity associated with hamartomatous tumors, abnormalities of the skin, and neurologic problems including seizures, intellectual disability, and autism. TSC is caused by pathogenic variants in either TSC1 or TSC2. In general, TSC2 pathogenic variants are associated with a more severe phenotype than TSC1 pathogenic variants. Here, we report a pathogenic TSC2 variant, c.1864C>T, p.(Arg622Trp), associated with a mild phenotype, with most carriers meeting fewer than two major clinical diagnostic criteria for TSC. This finding has significant implications for counseling patients regarding prognosis. More patient data are required before changing the surveillance recommendations for patients with the reported variant. However, consideration should be given to tailoring surveillance recommendations for all pathogenic TSC1 and TSC2 variants with documented milder clinical sequelae.

Imaging of Pediatric Salivary Glands

Salivary gland diseases in children are uncommon, and the relative incidence of pathologies is different than in adults. This article presents a comprehensive review of congenital and acquired disorders that affect the major salivary glands in the pediatric population, highlighting the imaging findings that are important in defining the appropriate diagnosis or narrowing of the differential diagnosis.

Laser ablation for mesial temporal lobe epilepsy: Surgical and cognitive outcomes with and without mesial temporal sclerosis

Laser interstitial thermal therapy (LITT) is a minimally invasive surgical technique for focal epilepsy. A major appeal of LITT is that it may result in fewer cognitive deficits, especially when targeting dominant hemisphere mesial temporal lobe (MTL) epilepsy. To evaluate this, as well as to determine seizure outcomes following LITT, we evaluated the relationships between ablation volumes and surgical or cognitive outcomes in 43 consecutive patients undergoing LITT for MTL epilepsy.

Atypical presentations of dysembryoplastic neuroepithelial tumors

Dysembryoplastic neuroepithelial tumors (DNETs) are World Health Organization grade 1 neoplasms, typically present as isolated cortical lesions with no associated edema. We present 3 rare cases of DNETs that were atypical in location (all were subcortical and 1 was bilateral), 2 of which displayed substantial growth over time. All 3 cases presented with seizures that were not well controlled on medications, followed by a successful cure of the epilepsy when these lesions were removed. These cases uniquely illustrate that DNETs can be present throughout the brain and may generate seizures even in a subcortical location, possibly due to containing neurons with the potential for aberrant microcircuitry. The slow, nonmalignant proliferation of these lesions may engage epileptogenic networks, leading to the onset of seizures. These cases carry implications for the management of these surgically treatable lesions. Thus far, there have only been a handful of cases of growth reported in nonmalignant DNETs, and 2 of these cases displayed growth over the interval of monitoring.