Russell A. Blinder

Modulation of cerebellar activities by acupuncture stimulation: evidence from fMRI study

Recent neuroimaging studies have revealed that acupuncture stimulation modulates human central nervous system including cerebral limbic/paralimbic and subcortical structures. Due to the wide and intricate connections with cerebrum, we hypothesized that anatomically specific areas in human cerebellum are also modulated by acupuncture stimulation beyond classical involvement of cerebellum in motor coordination. Functional MRI (fMRI) was used to investigate neural substrates responding to the acupuncture stimulation of Pericardium 6 (PC6, Neiguan), an acupoint relevant for the management of nausea including vestibular-related motion sickness. Sham stimulation near the acupoint and tactile stimulation on the skin of the acupoint were given as separate conditions. Psychophysical scores as well as the heart and respiratory rates were measured during each condition. Acupuncture manipulation on PC6, in comparison to the sham acupuncture and tactile stimulation conditions, selectively activated left superior frontal gyrus, anterior cingulate gyrus, and dorsomedial nucleus of thalamus. Acupuncture-specific neural substrates in cerebellum were also evident in declive, nodulus, and uvula of vermis, quadrangular lobule, cerebellar tonsil, and superior semilunar lobule. Negative MR signal changes, often seen during the acupuncture of analgesic points, were not observed in the present study. Our data suggest that cerebellum serves as important activation loci during the acupuncture stimulation of PC6, and clinical efficacy of PC6 may be mediated by the cerebellar vestibular neuromatrix.

Effects of turbulence on signal intensity in gradient echo images.

Although the appearance of laminar vascular flow in magnetic resonance (MR) images has been characterized, there is no general agreement about the effect of turbulent flow on MR signal intensity. This study uses a fast scan gradient echo pulse sequence to evaluate nonpulsatile turbulent flow in two different models. The first model simulated flow in normal vascular structure. It generated nonpulsatile, laminar and turbulent flow in straight, smooth-walled Plexiglas tubes. The second model simulated flow through a vascular stenosis. It generated nonpulsatile, laminar, and turbulent flow through an orifice. Velocities and flow rates ranged from low physiologic to well above the physiologic range (velocity = .3 to 280 cm/second, flow rate from .15 to 40 L/minute). Transition from laminar to turbulent flow was observed with dye streams. Turbulent flow in straight, smooth-walled vessels was not associated with a decrease in MR signal intensity even at the highest velocities and flow rates studied. The transition from laminar to turbulent flow through an orifice is not associated with a decrease in gradient echo signal intensity. As the intensity of the turbulent flow increases, however, there is a threshold above which signal intensity decreases linearly as turbulence increases (r = .97). This study suggests that flow in normal vascular structures should not be associated with decreased signal intensity in gradient echo images. Turbulent flow through areas such as valves, valvular lesions or vascular stenoses, may be associated with a decrease in gradient echo signal intensity.

Chemoradiotherapy for adenoid cystic carcinoma: preliminary results of an organ sparing approach.

Objectives:A retrospective review of primary chemoradiotherapy (CRT) for adenoid cystic carcinoma (ACC) was performed to determine if CRT might be considered as an alternative to radiotherapy and/or definitive surgery. Methods:All treatment-naive patients with ACC of the head and neck who were treated with definitive primary chemoradiotherapy using carboplatinum and paclitaxel at Dana-Farber Cancer Institute in 2000 through 2004 were identified. Information on site, stage, presenting symptoms, performance status, treatment, toxicity, and follow up were collected and tabulated for review. Results:Five patients were identified with previously untreated ACC of the head and neck who received primary carboplatinum/paclitaxel CRT for unresectability or organ preservation. Patients had a median age of 41, 4 had primaries in the paranasal sinuses invading the base of skull and 1 had a transglottic laryngeal lesion. All patients completed a course of definitive chemoradiotherapy without treatment break. Grade 3 mucosal reactions developed during CRT in all patients. With a median follow-up of 36 months (range, 20–43) all patients have local regional control; 1 patient developed distant metastases at 7 months and is alive at 20 months. Conclusions:Preliminary data suggest that carboplatinum/paclitaxel based CRT for ACC provides local regional control and is a potential alternative to surgery or radiotherapy for patients with locally advanced ACC. Carboplatinum/paclitaxel based CRT warrants further study.

Orbitocranial wooden foreign body: A pre-, intra-, and postoperative chronicle: Case report

OBJECTIVEIntraorbital wooden foreign bodies—usually from a low-velocity puncture—are elusive and demand a low threshold for further imaging. In patients with traumatic injuries, orbital and intracranial air from fractures may be present, and it is particularly easy to overlook a wooden fragment CLINICAL PRESENTATIONA 53-year-old equestrian was kicked in the face by the rear hoof of a horse. The event was captured on video by her husband. Although no obvious entry point in and around the eye was observed, her ocular examination was notable for superior orbital fissure syndrome and increasing intraocular pressure in the left eye. Closer inspection revealed a 5-mm laceration above her superior lid margin; imaging revealed a foreign body at the orbital apex with apparent communication with the cranial vault. INTERVENTIONWe proceeded with cranio-orbital exploration because of the risk of continued ocular damage in the setting of increasing intraocular pressure and the potential for infection of both the eye and the intracranial space from a suspected foreign body. A 3.0 cm × 0.5 cm fragment was found lodged in the orbital apex and removed. CONCLUSIONThe patient recovered well after surgery and a course of antibiotics and has returned to riding. This case report presents an algorithm for approaching cranio-orbital foreign objects of unclear identity and the favorable outcomes that may be achieved.

MR imaging of stump neuroma.

Painful stump neuromas in the postamputation patient are difficult to diagnose and treat. We report a case in which magnetic resonance allowed precise preoperative diagnosis and localization of such a lesion. Magnetic resonance, with its ability for long axis imaging in the extremity, is ideally suited for the workup of stump neuromas.

MR Imaging with Surface Coils in Primary Hyperparathyroidism

The use of magnetic resonance (MR) to preoperatively evaluate patients with primary hyperparathyroidism was assessed using a 1.5 T system and surface coil reception. Twenty-five patients with primary hyperparathyroidism were studied before surgical exploration. Axial images, 5 mm thick, were obtained from the thyroid cartilage to the sternal notch. Both T1-weighted [short repetition time (TR), short echo time (TE)] and T2-weighted (long TR, long TE) spin echo sequences were performed in most cases. Parathyroid adenomas typically demonstrated greater signal than surrounding tissues on T2-weighted sequences, yet demonstrated signal intensity that was less than or equal to normal thyroid tissue on T1-weighted sequences. Using these criteria, MR correctly identified 17 of 20 surgically proven parathyroid adenomas in the neck. Magnetic resonance appeared less sensitive in two patients with parathyroid hyperplasia, identifying only one of six hyperplastic glands. We conclude that MR with surface coils provides high contrast, anatomic delineation of the neck and is useful for preoperative localization of parathyroid tumors.

Single Photon Emission Computed Tomography (SPECT) Part II: Clinical Applications

The clinical applications of SPECT are just beginning to be defined since complete systems have only recently become available. SPECT studies are more difficult to perform than planar imaging studies, and close attention to quality control is important to obtain optimal studies. SPECT has higher lesion contrast and is able to detect smaller lesions than planar imaging in Tc-99m sulfur colloid liver studies. Preliminary results of SPECT T1-201 studies are encouraging, but further work comparing SPECT and planar imaging of T1-201 is needed. SPECT does give more information than planar imaging in certain bone imaging cases such as suspected avascular necrosis of the hip. Although interesting results have been published using SPECT in brain and lung perfusion studies, the clinical utility of this work has not been determined. The development of certain radiopharmaceuticals would enhance the future of SPECT. Technetium-99m labeled brain and myocardial perfusion agents would be ideally suited for SPECT studies. The ability to quantitate lesion volume (eg, in liver metastases) has not been studied and could be useful in following patents on chemotherapy. SPECT could give additional information if monoclonal antibodies labeled with I-123 or Tc-99m can be demonstrated to have appropriate sensitivity. The advantages of SPECT over planar imaging will be greater as new agents are developed.

Utilizing computed tomography as a road map for designing selective and superselective neck dissection after chemoradiotherapy

OBJECTIVE: To determine whether computed tomography can distinguish low risk neck levels that can be omitted when neck dissection is undertaken after chemoradiotherapy. STUDY DESIGN: Case series with chart review. SETTING: Tertiary care center. SUBJECTS AND METHODS: Head and neck squamous cell carcinoma patients undergoing neck dissection after chemoradiotherapy between January 1998 and June 2008. We compared computed tomography findings after chemoradiotherapy with neck dissection pathology results; used primary location and computed tomography findings to design selective or superselective neck dissection; and determined whether these surgeries would have contained all metastatic disease. RESULTS: A total of 104 patients were identified, providing 110 heminecks, 531 neck levels, and 3009 lymph nodes for analysis. Neck dissections were positive in 20 (19%) of 104 patients, corresponding to 20 hemineck dissections, 31 neck levels, and 53 lymph nodes. The negative predictive value for computed tomography was 95 percent. The negative predictive value for computed tomography per neck level was as follows: I, 100 percent; II, 96 percent; III, 96 percent; IV, 97 percent; and V, 96 percent. A selective neck dissection or a superselective neck dissection, guided by level specific computed tomography findings and limited to necks with post treatment partial response in one level, would have captured all disease in 52 (95%) of 55 and 51 (93%) of 55 heminecks. CONCLUSION: Negative computed tomography accurately predicts pathologic complete response at neck dissection. Neck dissection can be avoided in these patients. Additionally, computed tomography reliably identifies low risk neck levels that do not require dissection, permitting selective neck dissection or superselective neck dissection in partial response patients with limited residual disease.

A method for evaluating the bronchial circulation. Preliminary observations.

Due to the small size of the bronchial arteries, the bronchial circulation is difficult to study and remains poorly understood. We have utilized single photon emission computed tomography (SPECT) as a noninvasive means of studying the bronchial circulation. Imaging studies were performed in sheep before and after the introduction of a single pulmonary embolus. Digital bronchial arteriograms demonstrated the dilatation of the bronchial artery which is present on studies one week after embolization. SPECT bronchial perfusion scans reveal a wedge of increased activity that corresponds to a wedge of decreased activity on SPECT pulmonary perfusion images. Axial images available with SPECT provide information about regional alterations of bronchial perfusion not readily apparent on bronchial arteriograms.

CNS Relapse in Acute Promyeloctyic Leukemia

A 42-year-old female was diagnosed with acute promyelocytic leukemia (APL) with a translocation of chromosomes 15 and 17 involving the PML and RARA genes. On presentation she met criteria for low-risk disease on the basis of platelet count (50 10/L) and WBC count (0.8 10/L). The patient achieved a complete molecular remission after induction chemotherapy with all-trans-retinoic acid (ATRA) and idarubicin (AIDA) and underwent consolidation chemotherapy per the risk-adapted Spanish Cooperative Group for Hematological Malignancies Treatment (PETHEMA) regimen, on completion of which she remained in molecular remission. She subsequently received maintenance therapy with oral ATRA, 6mercaptopurine, and methotrexate per the Cancer and Leukemia Group B C9710 protocol. Two weeks after completion of maintenance therapy, the patient had a bone marrow examination that demonstrated molecular relapse, on the basis of a positive bone marrow reverse transcriptase polymerase chain reaction (RT-PCR) for PMLRARA that was confirmed on repeat study 4 weeks later. Peripheral blood counts, bone marrow morphology, and cytogenetics were normal. The patient reachieved molecular remission after two 30-day cycles of arsenic trioxide (ATO) and underwent autologous peripheral blood stem-cell transplantation (SCT) for consolidation, with high-dose busulfan and cyclophosphamide conditioning. Five months after SCT, the patient presented with 1 week of right-sided headache worse with neck flexion, 3 days of intermittent visual loss in her right eye, and paresthesias of the right leg. Magnetic resonance image revealed diffuse leptomeningeal enhancement. Figure 1 shows an axial T1-weighted, gadolinium-enhanced image demonstrating regions of leptomeningeal enhancement (arrows). Cerebrospinal fluid (CSF) analysis revealed blast cells that were CD33 and CD13 positive and HLA-DR negative, and RT-PCR confirmed the presence of PML-RARA transcripts. Figure 2 shows a diffuse infiltrate of myeloblasts and promyelocytes within the CSF (Fig 2A). On high-power view (Fig 2B), several abnormal promyelocytes are noted, with intense azurophilic granules, bilobed nuclei, and dispersed chromatin. Auer rods, single as well as multiple, are present. Bone marrow analysis