Bone marrow edema: pathophysiology, differential diagnosis, and imaging.

Bone marrow edema (BME) has been a topic of increasing interest in the literature in recent years. BME is associated with numerous pathologies and is becoming recognized not only as a considerable pain generator, but also as an entity which is, in some cases, significantly linked to the worsening of patient prognosis. To date, no thorough imaging review of BME has been published. An electronic literature search was conducted through PubMed with a time parameter of January 1975 through December 2007. The primary search parameter was "bone marrow edema." Over 800 papers were listed as written in English and involving humans. Other refining parameters included "AND syndrome," "AND transient," "AND arthritis," "AND infection," "AND tumor," "AND neoplasm," "AND iatrogenic," "AND radiation therapy," and "AND inflammation." More current articles were favored over dated articles on the same topic. A total of 106 journal articles were collected concerning BME and multiple pathologic processes. The data contained therein was compiled and organized into a comprehensive format. BME can be caused by, and found concurrent with, a broad spectrum of pathologies which exhibit a variety of imaging findings. BME is also associated with the deterioration of certain pathologies. This presentation is a comprehensive discussion of different pathological conditions inducing or associated with BME. Differential diagnosis through appropriate imaging is vital to case management and could contribute to the prevention or decreased progression of certain pathologies. Continued investigation into the imaging of BME and its associated diseases, as well as the effect of BME on prognosis, is warranted.

Hypothalamus and amygdala response to acupuncture stimuli in Carpal Tunnel Syndrome.

Brain processing of acupuncture stimuli in chronic neuropathic pain patients may underlie its beneficial effects. We used fMRI to evaluate verum and sham acupuncture stimulation at acupoint LI-4 in Carpal Tunnel Syndrome (CTS) patients and healthy controls (HC). CTS patients were retested after 5 weeks of acupuncture therapy. Thus, we investigated both the short-term brain response to acupuncture stimulation, as well as the influence of longer-term acupuncture therapy effects on this short-term response. CTS patients responded to verum acupuncture with greater activation in the hypothalamus and deactivation in the amygdala as compared to HC, controlling for the non-specific effects of sham acupuncture. A similar difference was found between CTS patients at baseline and after acupuncture therapy. For baseline CTS patients responding to verum acupuncture, functional connectivity was found between the hypothalamus and amygdala--the less deactivation in the amygdala, the greater the activation in the hypothalamus, and vice versa. Furthermore, hypothalamic response correlated positively with the degree of maladaptive cortical plasticity in CTS patients (inter-digit separation distance). This is the first evidence suggesting that chronic pain patients respond to acupuncture differently than HC, through a coordinated limbic network including the hypothalamus and amygdala.

Correlating acupuncture FMRI in the human brainstem with heart rate variability.

Past neuroimaging studies of acupuncture have demonstrated variable results for important brainstem nuclei. We have employed cardiac-gated fMRI with T1-variability correction to study the processing of acupuncture by the human brain. Furthermore, our imaging experiments collected simultaneous ECG data in order to correlate heart rate variability (HRV) with fMRI signal intensity. Subjects experienced one of three stimulations over a 31.5 minute fMRI run: (1) electro-acupuncture at 2Hz/15Hz over the acupoint ST-36 (2) electro-acupuncture at a sham non-acupoint, or (3) sensory control tapping over ST-36. The ECG was analyzed with power spectral methods for low frequency and high frequency components, which reflect the balance in the autonomic nervous system. The HRV data was then correlated with the time-varying fMRI signal intensity. Our data suggests that fMRI activity in the hypothalamus, the dorsal raphe nucleus, the periaqueductal gray, and the rostroventral medulla showed significant correlation with LF/HF ratio calculated from simultaneous HRV data. The correlation of time-varying fMRI response with physiological parameters may provide insight into connections between acupuncture modulation of the autonomic nervous system and neuroprocessing.

Functional impression and jaw registration: a single session procedure for the construction of complete dentures.

The conventional fabrication of complete dentures involves two separate clinical sessions for functional impression making and jaw registration. The presented method combines both procedures in one session. The aim of this study was to survey the three-dimensional tooth positions in complete dentures with reference to the ridges to establish arbitrary guideline values that could be used for the manufacturing of tooth-position analogue plastic rims on functional impression trays. New complete dentures were fabricated by supervised undergraduate students in the conventional manner for 104 edentulous patients. The position of the maxillary teeth was surveyed in the horizontal plane using the Schmuth 'vizor-measuring plate'. The vertical dimension of occlusion, represented as the distance between opposing ridge areas of the dentures in maximum intercuspation, was measured at different sites by means of a Gutowski gauge. The tooth positions on the dentures varied widely, e.g. the horizontal distances between the incisive papilla and the maxillary incisors was 7.1 +/- 2.3 (3-14) mm. The vertical dimension of occlusion, which is most important in the jaw registration, varied equally with an anterior inter-alveolar distance between 12 and 33 (20.4 +/- 4.0) mm. Arbitrary moulding of the tooth position-analogue plastic rims does not seems to be an ideal method of pre-shaping functional impression trays, because the individual anatomical variation is considerable. Alternatively, the horizontal and vertical tooth positions of functionally and aesthetically pleasing dentures should be measured to pre-shape the rims of functional impression trays in the maxillary and the mandibular jaw. Such trays are a valuable tool for functional impressions and an immediate preliminary jaw registration in the fabrication of new complete dentures. This method allows a first try-in of the full set-up in the third clinical visit without loosing precision.

The empty sella.

OBJECTIVE: To discuss the diagnostic imaging findings of an empty sella in a chiropractic patient with emphasis on magnetic resonance imaging (MRI) of normal and abnormal pituitary appearances. CLINICAL FEATURES: A 44-year-old woman started having headache, dizziness, nausea, vomiting, and diarrhea after an argument with her boyfriend. She had been treated for acute torticollis for three weeks when the new symptoms began. Consultation with an internist led to an MRI examination of the cerebellopontine angles to exclude an acoustic neuroma. The MRI demonstrated an enlarged empty sella. There was no history of pituitary tumor or other sellar disease. INTERVENTION AND OUTCOME: There was complete remission of the symptoms after 1 additional dizzy spell that occurred 3 days after the initial symptom. No intervention was performed, but the stress levels in her life had been reduced. CONCLUSION: An enlarged empty sella can be present without symptoms and can represent an incidental finding on radiography and MRI. However, an enlarged sella seen on lateral cervical spine radiographs should prompt further evaluation to rule out pituitary disease. The normal pituitary has a varied appearance and signal intensity on MRI depending on the patient's age and pregnancy status.

Solitary osteochondroma of the cervical spine.

OBJECTIVE: To discuss a case of cervical spine osteochondroma found incidentally during evaluation of a rib injury. To demonstrate diagnostic imaging, including plain film radiography, radionuclide bone scan, computed tomography and magnetic resonance imaging. CLINICAL FEATURES: This article presents the second reported case of osteochondroma associated with the C6 vertebral body. The classic imaging features of exostosis and a cartilaginous cap were identified. The osteochondroma was confluent with marrow of the C6 articular pillar. A biopsy was performed for confirmation of the lesion's histological character. INTERVENTION: Surgical resection was performed to remove the osteochondroma. CONCLUSION: Clinical examination, radiological evaluation and advanced diagnostic imaging helped detect and characterize an incidental cervical spine mass.

Magnetic resonance imaging of the wrist: occult osseous lesions.

This article illustrates the magnetic resonance imaging (MRI) features of occult osseous lesions in three different patients. All three patients suffered from a history of wrist trauma, but had negative plain film radiographs. The three types of occult lesions (bone bruise, microfracture and chronic osseous damage) are described, and their MRI characteristics are demonstrated by proton density and T2 weighted images. MRI proved to be the diagnostic modality of choice for the detection of posttraumatic intrinsic marrow changes.

The radiology of cervical spine injury.

Cervical spine injury is a frequent sequelae of accidental trauma. Clinical evaluation often fails to raise adequate suspicion of an underlying injury. Radiologic assessment frequently reveals recognizable signs of damage ranging from fractures to joint and soft tissue injuries. This paper reviews the pathomechanics, clinical and radiologic features of the most common patterns of cervical spine injury.

Comparison of enalapril and propranolol in essential hypertension.

In 40 patients with essential hypertension, enalapril was compared with propranolol as an antihypertensive agent in a double-blind study. The patients were randomly given either enalapril 5-10-20 mg bid or propranolol 40-80-120 mg bid in a treatment consisting of step-by-step increases in dosage. When the diastolic blood pressure remained greater than 90 mm Hg on the highest dosage, hydrochlorothiazide was added. Both enalapril and propranolol reduced blood pressure, although the patients tended to achieve lower blood pressures while on enalapril. More patients on propranolol required additional diuretic therapy than patients on enalapril. Propranolol reduced heart rate; with enalapril there were no changes in heart rate. Both drugs increased serum potassium and urea. Plasma renin substrate was reduced by enalapril, but raised by propranolol. Enalapril increased plasma renin activity and angiotensin I, while propranolol reduced both. Converting enzyme activity was lowered with enalapril but was unchanged with propranolol. Both drugs reduced angiotensin II. Plasma aldosterone concentration was more suppressed with propranolol than with enalapril.