Behavioral Variant Frontotemporal Dementia as a Serious Complication of Spontaneous Intracranial Hypotension.

BACKGROUND: Behavioral variant frontotemporal dementia (bvFTD) is a devastating early onset dementia. Symptoms of bvFTD may be caused by spontaneous intracranial hypotension (SIH), a treatable disorder, but no comprehensive study of such patients has been reported. OBJECTIVE: To describe detailed characteristics of a large cohort of patients with SIH and symptoms of bvFTD. METHODS: We identified patients with SIH who met clinical criteria for bvFTD. Patients were compared to a cohort of SIH patients without bvFTD. RESULTS: The mean age for the 21 men and 8 women was 52.9 yr (range, 37-65 yr). All 29 patients with bvFTD symptoms had hypersomnolence. Magnetic resonance imaging showed brain sagging in all patients, cerebrospinal fluid (CSF) opening pressure low in about half of patients, but a spinal CSF leak could not be detected in any patient. All patients underwent epidural blood patching, but 26 patients eventually underwent 1 or more surgical procedures. Overall, a good outcome was obtained in 21 patients (72%); 20 (91%) of 22 patients who had not undergone prior Chiari surgery compared to 1 (14%) of 7 patients who did undergo Chiari surgery (P < .003). Compared to SIH patients without symptoms of bvFTD (n = 547), those with bvFTD symptoms were older, more often male, less often demonstrated CSF leak on spinal imaging, and more often underwent surgery (P < .02). CONCLUSION: bvFTD in SIH is rare and associated with brain sagging and hypersomnolence. Spinal CSF leaks are rarely detected. bvFTD symptoms are often refractory to the usual percutaneous procedures but most patients can be cured.

ACR Appropriateness Criteria(®) myelopathy.

Myelopathy is a problem that requires imaging to distinguish among numerous specifically treatable causes. The first priority is to determine mechanical stability after trauma. Next, it is crucial to distinguish intrinsic disease from extrinsic compression-for example, by epidural abscess. Osteophytes or disc extrusions and metastatic compression are the most common causes of extrinsic lesions. Imaging approaches rely on clinical features such as pain, fever, trauma, and pattern of progression. CT is preferred initially in acute trauma and MRI in all other circumstances. Contrast-enhanced MRI is added when tumor or infection is suspected or with slow or stepwise progression, especially when pain is not prominent. Vascular imaging is used when arteriovenous malformation, fistula, or occlusive disease is suspected. Because the treatment of myelopathy is often complex, treatment planning may require more than one imaging study or sequential examination to assess interval change. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR Appropriateness Criteria® on cerebrovascular disease.

Stroke is the sudden onset of focal neurologic symptoms due to ischemia or hemorrhage in the brain. Current FDA-approved clinical treatment of acute ischemic stroke involves the use of the intravenous thrombolytic agent recombinant tissue plasminogen activator given <3 hours after symptom onset, following the exclusion of intracerebral hemorrhage by a noncontrast CT scan. Advanced MRI, CT, and other techniques may confirm the stroke diagnosis and subtype, demonstrate lesion location, identify vascular occlusion, and guide other management decisions but, within the first 3 hours after ictus, should not delay or be used to withhold recombinant tissue plasminogen activator therapy after the exclusion of acute hemorrhage on noncontrast CT scans. MR diffusion-weighted imaging is highly sensitive and specific for acute cerebral ischemia and, when combined with perfusion-weighted imaging, may be used to identify potentially salvageable ischemic tissue, especially in the period >3 hours after symptom onset. Advanced CT perfusion methods improve sensitivity to acute ischemia and are increasingly used with CT angiography to evaluate acute stroke as a supplement to noncontrast CT. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Impact of carbohydrate restriction with and without fatty acid loading on myocardial 18F-FDG uptake during PET: A randomized controlled trial.

BACKGROUND: Low-carbohydrate (LC) and high-fat, low-carbohydrate (HFLC) dietary preparations may enhance (18)F-FDG-PET-based imaging of small, inflamed structures near the heart by suppressing myocardial FDG signal. We compared myocardial (18)F-FDG uptake in patients randomized to LC, HFLC, and unrestricted (UR) preparations prior to (18)F-FDG-PET. METHODS AND RESULTS: We randomized 63 outpatients referred for oncologic (18)F-FDG-PET to LC, HFLC, or UR dietary preparations (1:1:1 allocation) starting the evening before PET. After eating dinner according to instructions, UR and LC patients fasted until FDG injection (mean time 745 minutes for UR, 899 minutes for LC), and HFLC patients drank a fatty drink 60-70 minutes prior to FDG injection. Attenuation-corrected PET imaging was performed 60 minutes after FDG administration. Maximal myocardial standard uptake values (MyoSUV(max)) were systematically measured in axial view and compared between the three groups. Using UR patients as reference, mean MyoSUV(max) was lower in LC patients (3.3 +/- 2.7 vs 6.2 +/- 5.2, P = .03) but not in HFLC patients (5.5 +/- 4.2, P = .63). Ratios of MyoSUV(max) to liver SUV(max), calculated to control for background uptake, were not significantly different amongst the groups (1.9 +/- 2.1 LC, 2.6 +/- 2.3 HFLC, 3.6 +/- 3.5 UR). CONCLUSION: In this small randomized controlled trial using UR diet as reference, LC dietary preparation followed by extended fasting resulted in significant myocardial uptake suppression.

Usefulness of 123I-MIBG scintigraphy in the evaluation of patients with known or suspected primary or metastatic pheochromocytoma or paraganglioma: results from a prospective multicenter trial.

UNLABELLED: Although (123)I-MIBG has been in clinical use for the imaging of pheochromocytoma for many years, a large multicenter evaluation of this agent has never been performed. The present study was designed to provide a prospective confirmation of the performance of (123)I-MIBG scintigraphy for the evaluation of patients with known or suspected primary or metastatic pheochromocytoma or paraganglioma. METHODS: A total of 81 patients with a prior history of primary or metastatic pheochromocytoma or paraganglioma and 69 with suspected pheochromocytoma or paraganglioma based on symptoms of catecholamine excess, CT or MRI findings, or elevated catecholamine or metanephrine levels underwent whole-body planar and selected SPECT 24 h after the administration of (123)I-MIBG. Images were independently interpreted by 3 masked readers, with consensus requiring agreement of at least 2 readers. Final diagnoses were based on histopathology, correlative imaging, catecholamine or metanephrine measurements, and clinical follow-up. RESULTS: Among 140 patients with definitive diagnoses (91, disease present; 49, disease absent), (123)I-MIBG planar scintigraphy had a sensitivity and specificity of 82%. For patients evaluated for suspected disease, sensitivity and specificity were 88% and 84%, respectively. For the subpopulations of adrenal (pheochromocytoma) and extraadrenal (paraganglioma) tumors, sensitivities were 88% and 67%, respectively. The addition of SPECT increased reader confidence but minimally affected sensitivity and specificity. CONCLUSION: This prospective study demonstrated a sensitivity of 82%-88% and specificity of 82%-84% for (123)I-MIBG imaging used in the diagnostic assessment of primary or metastatic pheochromocytoma or paraganglioma.

Metabolic and receptor imaging in patients with neuroendocrine tumors: comparison of fludeoxyglucose-positron emission tomography and computed tomography with indium in 111 pentetreotide.

OBJECTIVE: To determine whether positron emission tomography/computed tomography (PET/CT) and indium In 111 pentetreotide, individually or collectively, predict the outcome of patients with neuroendocrine tumors (NETs). METHODS: Between July 31, 2002, and May 4, 2007, 29 patients with previously diagnosed NETs underwent both PET/CT and indium In 111 pentetreotide imaging at our institution. The images were evaluated for the presence of abnormalities. Clinical outcomes were classified as survival without major morbidities, survival with severe complications of disease, or death. Time to outcome was measured in months from the imaging date to outcome. Kaplan-Meier survival curves were calculated in which patient outcome was compared with results on PET/CT and indium In 111 pentetreotide imaging. RESULTS: Of the 29 patients, 9 had abnormalities on both PET/CT and indium In 111 pentetreotide imaging. Two patients had abnormal findings on PET/CT but normal findings on pentetreotide imaging. In 5 patients, findings were normal on PET/CT but abnormal on pentetreotide imaging. In 13 patients, normal findings were noted on both PET/CT and pentetreotide imaging. Kaplan-Meier analysis demonstrated a significant survival advantage for patients who had normal findings on PET/CT in comparison with abnormal PET/CT findings (P = .01). Patients with normal findings on indium In 111 pentetreotide imaging had a higher but insignificant survival advantage over those with abnormal results on pentetreotide imaging (P = .08). CONCLUSION: For evaluation of NETs, PET/CT and indium In 111 pentetreotide are complementary. Increased metabolic activity in tumor cells is reflected by abnormalities on PET/CT. Patients who had abnormal PET/CT findings had a generally poorer prognosis and a more rapid clinical deterioration than those with normal PET/CT findings.

Clinical validation of the watershed sign as a marker for neuropsychiatric systemic lupus erythematosus.

OBJECTIVE: To study the relationship between single-photon-emission computed tomography (SPECT) brain imaging and neuropsychiatric signs/symptoms in a cohort of patients with systemic lupus erythematosus (SLE), analyzed using a stereotactic surface projection (SSP) technique. METHODS: Thirty-seven SLE patients were referred for 99mTc-ethyl cysteinate dimer SPECT brain imaging because of neuropsychiatric signs/symptoms. Nineteen normal controls were studied with the identical protocol. Reconstructed images were computed and Z scores were calculated using the SSP technique with the 2-sample t-tests comparing normal controls with SLE patients, and patients with mild cognitive dysfunction with those with severe cognitive dysfunction. The clinical characteristics of SLE patients were collected by retrospective chart review and categorized according to American College of Rheumatology case definitions for neuropsychiatric SLE. Cognitive dysfunction was rated by the treating physician on a scale of 0-3. RESULTS: Thirty of 37 SLE patients had abnormal SPECT results. SLE patients had reduced perfusion in the watershed areas of the frontal lobes bilaterally compared with controls. Additionally, SLE patients with severe cognitive dysfunction had more severe perfusion deficits than those with mild cognitive dysfunction. In some patients with severe cognitive dysfunction, the watershed areas had Z scores > or =4 SDs below controls. CONCLUSION: A convenience sample of patients with SLE and neuropsychiatric signs/symptoms demonstrated reduced perfusion in the watershed areas of the frontal lobes on SPECT scanning analyzed by the SSP technique. The severity of findings correlated with severity of cognitive dysfunction. The area of the brain affected is one that is susceptible to ischemia.

Thyroid stunning.

Debates regarding thyroid stunning-a phenomenon whereby a diagnostic dose of radioiodine decreases uptake of a subsequent therapeutic dose by remnant thyroid tissue or by functioning metastases-have been fueled by inconsistent research findings. Quantitative studies evaluating radioiodine uptake and qualitative studies using visual observations both compare thyroid function on the diagnostic scan (DxSCAN) versus the posttreatment whole-body scan (RxWBS). The variability of findings may be the result of a lack of consensus in clinical nuclear medicine regarding many parameters of radioiodine usage including the need to obtain a pretreatment diagnostic scan, appropriate therapeutic dose, time between therapy dose administration and DxSCAN, and how successful ablation is measured. In the studies considered in this review, those that used (123)I rather than (131)I for DxSCAN, allowed less time to elapse between diagnostic and therapy dose, and more time between therapy dose and RxWBS (at least 1 week), did not observe stunning. However, groups that recognized stunning did not demonstrate any difference in outcomes (determined by successful first-time ablation). Whether stunning is a temporary phenomenon whereby stunned tissue eventually rejuvenates, or whether observed stunning actually constitutes "partial ablation," is yet to be delineated.

Whole-body (18)F-FDG PET identifies high-risk myeloma.

UNLABELLED: The purpose of this study was to evaluate the clinical utility of whole-body PET with (18)F-FDG in patients with multiple myeloma and related monoclonal diseases. METHODS: Between July 1, 1996, and July 2000, 98 (18)F-FDG PET scans were obtained for 66 patients, with 25 patients having 2 or more scans. The results were compared with routine clinical and staging information, including CT and MRI scans, as indicated. Of the 66 patients, 16 had previously untreated active myeloma, 14 had monoclonal gammopathy of undetermined significance (MGUS), 10 had disease in remission, and 26 had relapsing disease. RESULTS: Negative whole-body (18)F-FDG PET findings reliably predicted stable MGUS. Of the 14 MGUS patients with follow-up of 3-43+ mo, myeloma has developed in only 1 (7%), at 8 mo. Conversely, the 16 previously untreated patients with active myeloma all had focal or diffusely positive scan findings. Four (25%) of 16 previously untreated patients with positive (18)F-FDG PET findings had negative full radiologic surveys. Another 4 (25%) of 16 patients had focal extramedullary disease. This was confirmed by biopsy or other imaging techniques. Extramedullary uptake also occurred in 6 (23%) of 26 patients with relapse. This extramedullary uptake was a very poor prognostic factor both before treatment and at relapse. For example, median survival was 7 mo for patients with disease relapse. Persistent positive (18)F-FDG PET findings after induction therapy predicted early relapse. In 13 (81%) of 16 patients with relapsing disease, new sites of disease were identified. The (18)F-FDG PET results were especially helpful in identifying focal recurrent disease in patients with nonsecretory or hyposecretory disease amenable to local irradiation therapy, which was used in 6 patients. CONCLUSION: Whole-body (18)F-FDG PET provides important prognostic information, which is clinically useful and complementary to conventional methods of evaluating plasma cell disorders. (18)F-FDG PET is a unique tool for evaluation of nonsecretory myeloma. Residual or recurrent disease after therapy, especially extramedullary disease, is a poor prognostic factor.