Per Olov Lundberg

Seizure risk associated with neuroactive drugs: Data from the WHO adverse drug reactions database

PURPOSE To explore the association between the use of neuroactive drugs and reports of epileptic seizures. MATERIAL Using the WHO adverse drug reactions (ADR) database, VigiBase, we surveyed reports of suspected seizures from 1968 until February 2006. Case reports of ADRs, that were classified as convulsions were collected and compared to the total number of ADRs reported. RESULTS The total number of ADRs was 7,375,325. The number of convulsive events was 71,471. The ratio of convulsive ADRs to the total number of ADRs reported for each drug was evaluated and expressed as a percentage. The 10 drugs most frequently associated with convulsive ADRs were maprotilene (14.42%), escitaloprame (9.78%), buproprione (9.49%), clozapine (9.0%), chlorprothiexene (8.89%), amoxapine (8.74%), donepezil (8.40%), rivastigmine (6.41%), quetiapine (5.90%) and trimipramine (5.69%). CONCLUSIONS Based on the reports in VigiBase, ADR reports relating to antidepressants, antipsychotic and cholinomimetic drugs included seizures more often than other neuroactive drugs.

Dopamine receptors in pituitary adenomas: PET visualization with 11C-N-methylspiperone.

Two patients with pituitary tumors were examined with positron emission tomography (PET) after intravenous administration of 11C-N-methylspiperone. In repeat studies the patients were given 1 mg of intravenous haloperidol prior to the administration of the radioligand to block the dopamine receptors. High uptakes of the radiolabeled ligand were seen in one of the tumors. With haloperidol pretreatment the uptake was lower, probably mainly showing the remaining unspecific binding. The most marked uptake and the largest effect of haloperidol pretreatment was seen in a patient with a hormonally active prolactinoma. Dopamine receptor binding in pituitary tumors can be demonstrated in vivo with PET, and quantification of this binding is possible using a compartmental model. This technique may be useful in improving our understanding of the variable response to medical treatment of prolactinomas with dopamine agonists as well as in the prediction of the effect of such treatment.

Malignant Prolactinoma with Multiple Intracranial Metastases Studied with Positron Emission Tomography

A rare case of a patient with multiple intracranial metastases from a prolactin-secreting pituitary neoplasm is described. At the age of 14 years, the patient had been operated on for a sellar tumor; he presented 12 years later with severe headache, at which time computed tomographic and magnetic resonance imaging scans revealed multiple intracranial metastases. Histopathology examination showed pituitary neoplastic cells with positive immunostaining for prolactin. The patient was investigated with positron emission tomography (PET) and dopamine D2-receptor binding, and the amino acid metabolism of the tumor was characterized in vivo. High dopamine D2-receptor binding and high amino acid metabolism were found in the tumor. The patient was subsequently treated with bromocriptine injections that resulted in a decrease in serum prolactin levels, decreased dopamine D2-receptor binding, reduced amino acid metabolism, and a reduction in tumor volume. This case demonstrates a beneficial effect of bromocriptine treatment in a patient with prolactinoma with multiple intracranial metastases. It also illustrates the great potential of PET in the in vivo characterization of the D2-binding and the high sensitivity of 11C-labeled L-methionine in the follow-up of treatment in patients with pituitary adenomas.

Mri of pituitary macroadenomas with reference to hormonal activity

SummaryIn 115 patients with pituitary macroadenomas, the findings on mid-field MRI were correlated with the hormonal activity of the tumours. Adenomas secreting growth hormone (GH), prolactin (PRL) and clinically nonsecretory adenomas were studied. Tumour size, invasiveness and signal intensity patterns were recorded. Relaxation times and ratios of signal intensity and proton density (relative to the corpus callosum) were analysed in areas of apparently solid tissue in a subgroup of 59 previously untreated patients. Invasiveness was more common in PRL-and GH-secreting adenomas than in the nonsecreting ones. Diffuse invasion of the base of the skull was most common in prolactinomas, and associated with a lower frequency of suprasellar tumour extension. In prolactinomas, a correlation was found between the maximum serum PRL level and tumour size. Haemorrhagic, cystic or necrotic areas were less common in GH-secreting tumours than in the other types. Haemorrhage was more common in prolactinomas than in nonsecreting tumours. MR parameters were similar in prolactinomas and nonsecreting adenomas, but indicated a smaller amount of water in GH-secreting tumours.

Kinetics of four 11C-labelled enkephalin peptides in the brain, pituitary and plasma of Rhesus monkeys

The kinetics of four 11C-labelled enkephalin peptides: Tyr-Gly-Gly-Phe-Met (Met-enkephalin), Tyr-D-Met-Gly-Phe-Pro-NH2 [D-Met2,Pro5)-enkephalinamide), Tyr-D-Ala-Gly-Phe-Met-NH2 (DALA) and Tyr-D-Ala-D-Ala-Phe-Met-NH2 (TAAFM) all labelled at the methyl group of methionine was studied in the Rhesus monkey. After intravenous administration, the regional kinetics in the head, lungs, liver and kidneys were followed by means of positron emission tomography (PET). The total radioactivity in blood and urine was measured and the composition of 11C-labelled peptide fragments in plasma in vivo and in vitro was analysed by liquid chromatography. With PET, an increased radioactivity was observed in the brain and pituitary over the 60-90 min investigation period after i.v. injection of the peptides. The highest radioactivities were noted for Met-enkephalin, followed by DALA and D-Met2, Pro5-enkephalinamide, while very low radioactivities were found for TAAFM. The uptake of Met-enkephalin- and DALA-derived radioactivity was of the same order as has previously been shown for morphine in the brain and considerably higher than that of D-Met2,Pro5-enkephalinamide and TAAFM, respectively. A large fraction of the brain radioactivity derived from Met-enkephalin and DALA probably emanated from [11C]methionine as indicated by plasma and urine analysis. Met-Enkephalin was rapidly eliminated from plasma in vitro with an half-life of less than two minutes, whereas DALA was stable suggesting clearance by other tissues than plasma. In conclusion, both Met-enkephalin and DALA, were rapidly hydrolyzed in vivo to [11C]methionine. [11C]Methionine was probably taken up in the brain, as the radioactivity increased with time in different brain regions as measured with PET.D-Met2,Pro5-Enkephalinamide and TAAFM were virtually stable in vivo and at least part of the radioactivity observed in the brain may have represented the intact peptide.

Creutzfeldt-Jakob disease in Sweden

OBJECTIVES To find and investigate, retrospectively, as many cases as possible of Creutzfeldt-Jakob disease (CJD) in Sweden dying during the period 1 January 1985 to 31 December 1996 and to detect any possible case(s) of new variant CJD. METHODS The patients were found through computer search of all death certificates in Sweden on which CJD was mentioned, through information from the Swedish neuropathologists, and spontaneous reports from Swedish doctors and hospitals. Data concerning the patients were then collected from patients’ case records and from brain histopathology reports. RESULTS In total 72 cases of spongiform encephalopathy were confirmed as definite by neuropathology, one of them with Gerstmann-Stäussler-Scheinker disease. In 51 further cases there were no brain pathology data but the diagnosis “probable” (37 patients) or “possible” (14 patients) CJD according to WHO criteria could be made on clinical grounds. There was a variation in number of deaths/year, from a minimum of five (1985) to a maximum of 16 (1990). Sixty patients died during the period 1985–90 and 62 during 1991–6. The sex ratio was nearly 1:1. Calculated for a population of 8.6 million (mean of 12 years) in Sweden this gives 1.18/million/year. Age at the time of the presenting symptoms ranged from 34 to 84 years. Only one patient was under 40 at the onset of symptoms. He had a spongiform encephalopathy but prion protein staining was negative. The duration of symptoms that could be attributed to CJD was 6 months or less in 75 cases, 7–12 months in 16 cases, 1 to 2 years in 15 cases, and more than 2 years in 16 patients. By definition all patients were demented. Other more common symptoms and signs were aphasia, dysphasia, dysathria, ataxia, myoclonus, pareses of the extremities, rigidity or spasticity, different types of hyperkinesias, and other psychiatric symptoms (depression, anxiety, and aggressiveness). Less common symptoms were hallucinations (mainly visual), visual defects, sensory symptoms (paraesthesias, itching, or pain), apraxia of swallowing, and disorders of eye movements. CONCLUSIONS The incidence, the symptomatology, the age distribution (age in years at onset and at death), and the duration of illness were similar to those of other countries except for the cases of new variant CJD in the United Kingdom. There is so far no indication of any cases of new variant CJD in Sweden.

Amino Acid Distribution and Metabolism in Pituitary Adenomas Using Positron Emission Tomography with D-[11C]Methionine and L-[11C]Methionine

Four patients with hormonally inactive pituitary adenomas were examined with positron emission tomography (PET) after injection, during different examinations, of L-[methyl-11C]methionine and D-[methyl-11C]methionine, respectively. After the rapid distribution phase, the enantiomer L-[11C]methionine, which is metabolically active, showed a considerable continuous irreversible trapping attributed to amino acid metabolism. The stereoisomer D-[11C]methionine, which does not participate in protein synthesis, showed a rapid distribution within the whole adenoma tissue, with a distribution space on the order of 100%. A minimal irreversible trapping was observed which could be explained by technical factors. It is concluded that PET using the two enantiomers allows a separation of passive distribution and metabolism, and that L-[11C]methionine can be used for in vivo quantitative studies of amino acid metabolism of pituitary adenomas.

Weekly headache periodicity and the effect of weather changes on headache.

A weekly periodicity in the occurrence of headache was found in 53 patients with migraine and in 20 with tension headache during an observation period of four weeks. In the migraine group the frequency was highest on Thursday and on Saturday and lowest on Sunday–Monday, and in patients with tension headache it was lowest on Sunday–Tuesday and highest on Friday. During the observation period several climatic factors were recorded. After correction for the weekly periodicity a highly significant correlation was found in the migraine group between headache frequency, on the one hand, and atmospheric pressure and outdoor temperature recorded 1–3 days later, on the other.

Vasopressin test in cases of optic atrophy and optic neuritis

The vasopressin test gave pathological results in 12 cases of optic atrophy and normal results in three cases. One of the patients with a pathological response had Lebers disease and three had tobacco-alcholic amblyopia, while in the rest the optic atrophy was of uncertain origin. In the cases with normal results the aetiology was also unclear. The Metopirone test was normal in 13 cases and pathological in only one case of optic atrophy. In three out of five patients with optic neuritis the vasopressin test gave pathological responses. The high frequency of pathological vasopressin tests in patients with optic lesions indicates a simultaneous disturbance of the hypothalamo-hypophyseal function. The background to this might be a disturbed vascular supply. The vasopressin test was of no help in diagnosing tumours as a cause of optic atrophy.