(18)F-fluorodeoxyglucose and (18)F-flumazenil positron emission tomography in patients with refractory epilepsy

BACKGROUND

Epilepsy is a neurological disorder characterized by epileptic seizures as a result of excessive neuronal activity in the brain. Approximately 65 million people worldwide suffer from epilepsy; 20-40% of them are refractory to medication therapy. Early detection of disease is crucial in the management of patients with epilepsy. Correct localization of the ictal onset zone is associated with a better surgical outcome. The modern non-invasive techniques used for structural-functional localization of the seizure focus includes electroencephalography (EEG) monitoring, magnetic resonance imaging (MRI), single photon emission tomography/computed tomography (SPECT/CT) and positron emission tomography/computed tomography (PET/CT). PET/CT can predict surgical outcome in patients with refractory epilepsy. The aim of the article is to review the current role of routinely used tracer 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) as well as non routinely used (18)F-Flumazenil ((18)F-FMZ) tracers PET/CT in patients with refractory epilepsy.

CONCLUSIONS

Functional information delivered by PET and the morphologic information delivered by CT or MRI are essential in presurgical evaluation of epilepsy. Nowadays (18)F-FDG PET/CT is a routinely performed imaging modality in localization of the ictal onset zone in patients with refractory epilepsy who are unresponsive to medication therapy. Unfortunately, (18)F-FDG is not an ideal PET tracer regarding the management of patients with epilepsy: areas of glucose hypometabolism do not correlate precisely with the proven degree of change within hippocampal sclerosis, as observed by histopathology or MRI. Benzodiazepine-receptor imaging is a promising alternative in nuclear medicine imaging of epileptogenic focus. The use of (11)C-FMZ in clinical practice has been limited by its short half-life and necessitating an on-site cyclotron for production. Therefore, (18)F-FMZ might be established as one of the tracers of choice for patients with refractory epilepsy because of better sensitivity and anatomical resolution.

[Bevacizumab as first-line therapy in metastatic renal cell carcinoma: Progression-free survival for 3 years]

We report the case of a 72-year-old woman who was diagnosed in 2006 with renal cell cancer (RCC) and had undergone consecutive tumor nephrectomy (clear-cell RCC, Fuhrmann grade II, stage pT3a, R0). Over the years, the patient underwent several surgical and radiological interventions due to various metastatic lesions. This case report describes the 3-year progression-free survival in a patient who underwent first-line therapy with the monoclonal antibody bevacizumab. Except for hypertension, the patient does not suffer currently from any other side effects of bevacizumab therapy.

Hereditary neuropathy with liability to pressure palsies presenting with sciatic neuropathy

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal-dominant disorder associated with recurrent mononeuropathies following compression or trivial trauma. Reports on sciatic neuropathy as the presenting manifestation of HNPP are very scarce. We report on a 21-year-old previously healthy man who was admitted with sensorimotor deficits in his left leg. He had no history of preceding transient episodes of weakness or sensory loss. Clinical and electrophysiological examinations were consistent with sciatic neuropathy. Cerebrospinal fluid investigation and MRI of the nerve roots, plexus, and sciatic nerve did not indicate the underlying aetiology. When extended electrophysiological tests revealed multiple subclinical compression neuropathies in the upper limbs, HNPP was contemplated and eventually confirmed by genetic testing.

Mononeuritis multiplex: association with infectious condition and familial background in a tropical environment: a case report

Mononeuritis multiplex is characterized by an asymmetric pattern with affection of the peripheral nervous system; this form of polyneuropathy is often seen in non-systemic vasculitis. We present a case of multiplex neuropathy in a patient with histologicaly verified Hailey-Hailey disease. With the exception of this comorbidity--in its characteristic form presenting additionally with a superinfected subdermal node--we did not find any other possible etiologic factor possibly causative of multiplex neuritis. The diagnosis was confirmed by electrophysiological testing. To our knowledge, this is the first case report indicating a possible relationship between Hailey-Hailey disease and multiplex neuritis. There exists only one related study in the literature, which was conducted in Columbia--our patient's home country. This study delineates a clinically similar dermal disease (pemphigus foliaceus) in patients from rural Colombia (El Bagre). The authors detected anti-neuronal antibodies which were interpreted to be responsible for the pathognomonic burning sensations.

Rare clinical findings in a patient with sporadic hemiplegic migraine: FDG-PET provides diminished brain metabolism at 10-year follow-up

BACKGROUND

Sporadic hemiplegic migraine (SHM) is defined as migraine attacks associated with some degree of motor weakness during the aura phase and where no first-degree relative has identical attacks. SHM has a wide inter- and intraindividual clinical spectrum and, in case of prolonged aura symptoms and disturbed consciousness, can mimic several other acute neurological diseases.

CASE

In 1996, during his wedding night, a 28-year-old man developed left face, arm and leg weakness, nausea and a throbbing headache. Neurological examination on presentation revealed stupor, fever, meningism and left hemiplegia. There were no abnormalities on emergency magnetic resonance. Lumbar puncture showed mild lymphocytic pleocytosis and slightly elevated protein. He received symptomatic treatment. Subsequent genetic analysis revealed the T666M mutation in the CACNA1A gene of chromosome 19. He was diagnosed with SHM. In 2005, at the end of another episode of hemiplegic migraine (HM), he for the first time developed an episode of paranoid psychosis with anxiety and visual hallucinations. The psychiatric symptoms resolved within a week.

DISCUSSION

All perfusion SPECT and transcranial Doppler studies performed in the first days of HM attacks were consistent with hyperemia of the hemisphere contralateral to the neurological signs. FDG-PET/CT in January 2013 revealed a diffusely reduced glucose metabolism of the supratentorial cortex and marked asymmetric hypometabolism of the left cerebellum. The finding of progressive cortical metabolic dysfunction over years appears as a new finding. Glucose hypometabolism may indicate primary neuronal dysfunction as the cause of the prolonged deficits.

Pitfall in follow-up imaging of pancreatic neuroendocrine tumor by somatostatin receptor PET

56-year old woman was operated of a pancreatic NET in May 2011. Abdominal pain had led to imaging and consecutively the finding of cholecystolithiasis and the tumor. The gall bladder, left hemi-pancreas, regional lymph nodes and the (unintentional injured) spleen were resected. At routine control examination in October 2012 CT presented three contract enhancing intra-abdominal lesions with a diameter of 2-3.5 cm. Consecutively 68Ga-DOTA-NOC PET-CT showed high tracer uptake (SUV 10-12) at these lesions. Therefore a relapse of the neuro-endocrine tumor was suspected. After reoperation in December 2012 histology did not reveal any sign of neuroendocrine tumor but identified spleen tissue most probably caused by splenosis accidentally seeded at the first operation. Physiologically the spleen is highly avid at 68Ga-DOTATOC PET, but splenosis presents with less standard uptake value. In our case the described lesions presented with an SUV quite comparable to that of neuroendocrine tumor tissue.

[A biomechanical analysis of cyclical hand motor function: a pilot study in different Parkinsonian syndromes]

INTRODUCTION

Clinical assessment of hand bradykinesia in Parkinson's disease (PD) focuses mainly on the frequency, amplitude and rhythm of movements, thereby subjectively evaluating the correct performance of hand movements. The aim of the study was to quantify hand bradykinesia with kinematic data in different Parkinsonian syndromes.

PATIENTS AND METHODS

This retrospective study compared patients with idiopathic PD (IPD, n = 18), atypical Parkinson's syndrome (APS, n = 17), secondary Parkinson's syndrome (SPS, n = 18) and healthy controls (C, n = 18). All patients were receiving the best medical treatment. Hand movements were recorded using an ultrasound-system (Zebris®, Isny, Germany). Subjects were asked to perform pronation/supination of the forearm (diadochokinesis), flexion/extension of the hand (hand tapping) and tapping of the index finger. Mean amplitude, mean frequency and mean variability of movements were determined.

RESULTS

APS patients had significant complex hand movement disability with reduced amplitude and frequency in combination with increased motion variability in all movement tasks. The key disturbance in the IPD group concerned the rhythm in hand tapping and index finger tapping in combination with moderately reduced velocity and range of motion in all conditions. The cyclical hand movement characteristics in SPS patients showed movement slowness with normal amplitude and variability in all motor conditions.

CONCLUSION

Our results suggest that computerized quantitative analysis of cyclical hand movements can characterize and identify different representations of hand bradykinesia in different Parkinsonian disorders and hence may help clinicians to accurately assess therapeutic targets and outcome of interventions.

Serum leptin is correlated to high turnover in osteoporosis

OBJECTIVE

Clinical data have suggested that obesity protects against osteoporosis. Leptin, mainly secreted by white adipose tissue, might be involved by mediating an effect on bone metabolism. This study was conducted to investigate a possible relationship of leptin and bone turn-over in postmenopausal women with osteoporosis.

METHODS

We measured bone mineral density (BMD), serum leptin levels and markers of bone metabolism, including osteocalcin and cross-laps in 44 patients with osteoporosis. The main group consisted of 32 postmenopausal women.

RESULTS

Mean serum leptin was 13.1 microg/L and showed no statistically significant difference to the levels measured in a collective of normal persons adjusted for age and BMI. When related to serum cross-laps as markers of bone resorption, a positive correlation (p<0.05) was observed, whereas no correlation with osteocalcin could be seen.

CONCLUSIONS

A dual control of bone formation by leptin is assumed: This involves local mechanisms acting on osteoblasts and a central inhibitory effect on bone metabolism via a hypothalamic relay. Our data indicate that the net effect of circulating leptin may cause bone loss and is significantly related to high-turnover serum bone markers, at least in postmenopausal women with osteoporosis.

[SPECT and FDG-PET in diagnostics of neurolues]

Syphilis is a recurrent treponematosis of acute and chronic evolution. In general it is either sexually or congenitally transmitted. Primary syphilis appears as a single and painless lesion. Secondary syphilis may manifest years later, the secondary bacteremic stage is accompanied by generalized mucocutaneous lesions. Tertiary disease can be disseminated to bones and virtually any organ, involving principally the ascending aorta and the central nervous system. Nuclear medicine provides diagnostic methods in case of skeletal manifestations by bone scan - identifying periostitis and osteomyelitis. Hepatic gummas can be imaged by 99m-Tc-colloid liver scintigraphy. In neurosyphilis brain perfusion SPECT enables imaging of cerebral involvement by small vessel endarteritis resulting from syphilitic vascular disease. 18-FDG PET is also useful to evaluate neurosyphilis, a reduction of brain glucose consumption is observed. The technique adequately enables imaging of therapeutic response and might be superior to morphologic imaging. We present our experiences with these nuclear medicine methods in patients with neurolues. The incidence of neurolues is estimated at 2 per 100.000 inhabitants worldwide, migration processes might bring a re-emergence of this disease to Austria and other developed countries of the EU. Scintigraphic methods should be kept in mind for diagnostic evaluation of neurosyphilis.

Causes and Prognosis of Nontraumatic Acute Renal Failure Requiring Dialysis in Adult Patients with and without Diabetes

Despite advanced techniques of renal replacement therapy the overall mortality of patients with ARF is still high. The majority of patients with ARF requiring dialysis are those with nontraumatic ARF. In a retrospective study we compared the causes of nontraumatic ARF, the risk factors for the development of renal failure and the mortality rates in patients with and without diabetes mellitus who received dialysis therapy in the years 1991-2000. A total of 232 patients were included in the study, 34 (14.6%) of them with and 198 patients (85.4%) without diabetes. The predominant causes of nontraumatic ARF like congestive heart failure (26.4 vs. 13.6, p < 0.05) and hypotension/hypovolemia (20.6 vs. 7.6%, p < 0.05) occurred more frequently in diabetic patients. The prevalence of sepsis (8.8 vs. 10.1%, NS), malignancy/ hypercalcemia (5.8 vs. 11.6%, NS) and other causes of nontraumatic ARF were similar in both groups. The prevalence of hepato-renal syndrome (5.8 vs. 13.6%, p < 0.05) and acute kidney graft failure (2.9 vs. 15.1%, p < 0.05) was higher in the nondiabetic individuals. Patients with diabetes showed more often chronic predictors for the onset of ARF like pre-existing hypertension (93.6 vs. 51.0%, p < 0.05), congestive heart failure (44.1 vs. 14.6%, p < 0.005), pre-existing renal insufficiency (76.4 vs. 46.9%, p < 0.05) and ACE-inhibitor therapy (32.3 vs. 9.6%, p < 0.005). Additionally, the prevalence of multiple organ failure (MOF) as prognostic factor was significantly higher in the diabetic patients (47.0 vs. 21.7%, p < 0.05). The mean number of dialyses therapy was 4.7 vs. 4.5 per patient. The overall mortality was 41.1 vs. 44.% (NS). In conclusion, the prevalence of the most common causes of nontraumatic ARF was different between the patients with and without diabetes. The diabetic individuals had more frequently predictors for the onset of ARF. The overall mortality was approximately the same in both groups.

Multitracer study in Heidenhain variant of Creutzfeldt-Jakob disease: mismatch pattern of cerebral hypometabolism and perfusion imaging

Creutzfeldt-Jakob disease (CJD) is a subacute spongiform encephalopathy. This fatal prion disease is characterized by rapidly progressive dementia with a variety of neurological disorders. Diagnostic methods provided by nuclear medicine might be helpful for evaluation of patients with probable CJD as additional diagnostic tools to MRI and cerebro-spinal fluid evaluation. The experience with FDG-PET and brain perfusion SPECT is presented.

Somatostatin-receptor positive brain stem glioma visualized by octreoscan

In diffuse brainstem gliomas often surgical biopsies cannot be obtained. The diagnosis relies upon imaging criteria, first line being MRI. Gliomas generally express somatostatin receptors (SSTR), which might enable receptor imaging. We present the case of a female adolescent with acute onset of hallucinations, dysphagia and diplopia. MRI detected a suggestive large pontine glioma. This lesion presented with marked In-111-pentreotide tracer uptake. SSTR-scan provided information about SSTR-expression, tumour viability and extension. Radiopeptide therapy for selected patients might be discussed.

Hyperthyroidism affects arterial stiffness, plasma NT-pro-B-type natriuretic peptide levels, and subendocardial perfusion in patients with Graves' disease

BACKGROUND

Arterial stiffness is thought to play a critical role in the pathogenesis of cardiovascular events, and in hyperthyroidism increased cardiovascular event rates have been reported.

AIM

To investigate markers of systemic arterial stiffness, volume homeostasis, and subendocardial perfusion and its interrelationship in patients with Graves' disease (GD) in hyperthyroidism and euthyroidism.

METHOD

Aortic augmentation index (AIx@75) as a measure of systemic arterial stiffness and subendocardial viability ratio (SEVR) as a surrogate measure of subendocardial perfusion were assessed by applanation tonometry in 59 patients with GD in hyperthyroidism and euthyroidism, and measurements were compared to plasma levels of NT-pro-B-type natriuretic peptide (NT-ProBNP).

RESULTS

AIx@75 and NT-ProBNP levels were significantly increased in hyperthyroidism compared to euthyroidism and were positively correlated with each other. SEVR was significantly decreased in hyperthyroidism compared to euthyroidism, mainly due to increased heart rates as shown by the heart rate-corrected SEVR75.

CONCLUSIONS

In hyperthyroidism, patients with GD exhibited increased systemic arterial stiffness, paralleled by increased levels of NT-ProBNP, a marker of volume overload. The decreased subendocardial perfusion in hyperthyroidism seemed to be mainly due to increased heart rates. The observed unfavorable hemodynamic alterations in hyperthyroidism may serve to explain increased cardiovascular event rates in patients with GD.