Free drug levels monitoring as a detector of false metabolic refractory epilepsy

Unbound and total plasma levels of carbamazepine (CBZ) and phenobarbital (PB) were evaluated in a group of 12 refractory patients out of 397 subjects, with normal values of total drug concentration and unbound levels below the expected ones. We established a minimal acceptable 'subtherapeutic' free drug level, i.e. less than 9.62 micrograms/ml for PB and 1.36 micrograms/ml for CBZ. PB and CBZ dosages were increased during a 3-month period. We observed a normalization of free levels, unaccompanied by a significant decrease in seizure frequency. Free drug level monitoring may prove to be an unchallenged detector of false metabolic refractory epilepsy.

Distribution of diphenylhydantoin in the brain during experimental status epilepticus of the cat

The distribution of diphenylhydantoin (PHT) (40 mg/kg i.p.) in the brain was investigated in cats with convulsive generalized (group 1) and focal penicillin-induced status epilepticus (group 2), and in controls. A significant increase in the amount of PHT entering the brain during the convulsive status was found, with peak brain levels at 45 min (12 +/- 3.2 micrograms/g vs. 6.0 +/- 0.8 in normal cats, P less than 0.05). In the focal status brain concentrations of PHT reached levels intermediate between controls and group 1 cats. At 15 min, elevated blood levels of the drug were paralleled by increased concentrations in the brain, whereas at 30 and 45 min other factors, such as changes in cerebral blood flow, cerebral pH, vascular resistance, metabolic derangement and blood-brain barrier disruption were presumably responsible for the altered brain PHT uptake. The relevance of these data to clinical practice is discussed, in relation to the treatment of human status epilepticus and the potentially neurotoxic effects of the drug.

In vivo response times for a heated skin surface CO2 electrode during rest and exercise

The continuous, noninvasive estimation of arterial carbon dioxide tension (PaCO2) by heated skin surface electrodes has recently become available for pediatric patients. Skin surface (PsCO2) electrodes can enhance the safety of procedures such as intubation, bronchoscopy, ventilator changes, sleep studies, or measurement of the ventilatory response to CO2 or hypoxia. However, clinical situations that include rapid changes in PaCO2 demand knowledge of the in vivo response time. We compared the response of a heated PsCO2 electrode to end tidal CO2 (PetCO2) during abrupt changes in inspired CO2 from room air to 7% CO2 and back to room air. We obtained 54 curves on nine healthy subjects. There was an initial lag time with less than a 10% change in PsCO2. Then PsCO2 approached PetCO2 exponentially. For subjects at rest changing from breathing room air to 7% CO2, the initial lag time was 40 +/- 2 seconds and the 50% response time of the exponential portion was 46 +/- 3 seconds. Thus, it took 86 seconds for the electrode to record a 60% response to an abrupt increase in inspired CO2. The initial lag and 50% response time were considerably shorter during exercise (30 +/- 2 and 33 +/- 2 seconds) and even shorter when switched from breathing 7% CO2 to room air (23 +/- 2 and 21 +/- 2 seconds). Exercise did not further reduce the response time when CO2 was initially elevated, suggesting the faster response time was due to vasodilation of the skin due to elevated CO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac side effects of phenytoin and carbamazepine. A dose-related phenomenon?

Three patients with dystrophia myotonica and echocardiographic signs of subclinical cardiopathy had cardiac side effects during oral treatment with phenytoin sodium or carbamazepine. These side effects were dose related: ventricular tachycardia appeared at a toxic serum phenytoin level in one patient and disappeared as the concentration fell within the therapeutic range, and atrioventricular block grade 1 developed in two patients at low serum carbamazepine levels, its severity increasing with the drug level. Given the risk of dangerous side effects, cardiac status needs to be carefully assessed before administration of phenytoin or carbamazepine in the treatment of dystrophia myotonica.

Brain distribution of carbamazepine and phenobarbital given in combination in experimental epilepsy

This study describes the brain distribution of carbamazepine (CBZ) and phenobarbital (PB) given intraperitoneally in combination to cats rendered epileptic by parenteral penicillin and by penicillin topically applied on neocortex. A control group of normal cats was also evaluated pharmacokinetically. Levels of both drugs were extremely low in brains of controls (CBZ 0.8 +/- 0.02 micrograms/g; PB 1.49 +/- 0.7 micrograms/g of fresh tissue), but higher levels were found in brains of epileptic cats with CBZ showing the greater increase (peak concentrations five- to sixfold higher than the corresponding CSF free fraction vs. three- to fourfold higher for PB). This might have been partially due to the ability of CBZ to prevent the metabolic alterations associated with severe convulsions, and hence the binding impairment. As this event had no effect of potentiation on CBZ anticonvulsant activity, the present data confirm previous reports indicating that there is no experimental evidence that two drugs are better than one in controlling epilepsy.

Human undifferentiated thyroid carcinoma synthesizes and secretes 19S thyroglobulin

Thyroglobulin (Tg) biosynthesis and secretion have been studied in one case of undifferentiated small spindle cell human thyroid carcinoma. From tumor tissue were extracted 32 mg of soluble proteins per gram of wet tissue, compared with 54 mg from control gland; after ammonium sulfate fractionation, density gradient centrifugation, and immunoprecipitation, 1.3 mg of Tg per gram of wet tissue, compared with 31.2 mg from control, were purified. By incubating in vitro up to 3 hours tumor slices with tritiated leucine, galactose, and 125I, the rate of incorporation of leucine and galactose increased with time in tumor tissue. However 125I incorporation into soluble proteins from tumor, at 3 hours of incubation, was only 1.7% of control value. By density gradient centrifugation of labeled soluble proteins a well-separated component sedimenting in the 19S peak was identified. No radioiodine was detected in the 19S fraction which showed the immunoreactive properties of 19S and was poor in 127I and sialic acid. In the incubation medium of tumor were secreted 0.4 mg of 19S Tg per gram of wet tissue compared with 48 mg of tissue in the control gland. Thus the undifferentiated thyroid carcinoma synthesizes a protein with the physiochemical and immunologic properties of 19S Tg. The undifferentiation of thyroid cells does not affect the biochemical steps involved in the synthesis of Tg.

Transitory subclinical and permanent hypothyroidism in the course of subacute thyroiditis (de Quervain)

Sixty-two patients affected with subacute thyroiditis (SAT) were followed for a mean period of 14 months (range 1-40), by monitoring thyroid hormone levels in basal condition, pituitary TSH reserve, antithyroglobulin (TgAb) and antimicrosomal antibodies ( MsAb ), in order to study the natural course of the disease and to characterize its intermediate phase. In the first phase the mean serum iodothyronine levels were within normal limits, nevertheless elevated T3 and T4 levels were detected in 34 (54%) and 20 (32%) patients, respectively. The next phase was characterized by normal serum iodothyronine levels; TRH stimulation test, however, showed a significant increase of pituitary TSH reserve in 35 (56%) patients. All parameters reverted gradually towards normal in all but 3 patients, who showed overt permanent hypothyroidism. TgAb and MsAb were positive in the early stage in 15 (24%) and 40 (64%) patients, respectively, disappearing at the end of the follow-up period in all but one patient; this particular patient belonged to the group of 3 patients affected with permanent hypothyroidism. Our data indicate that the onset of SAT is characterized by transient hyperthyroidism and that transient subclinical hypothyroidism characterizes the next phase. TRH stimulation test is required for the diagnosis of the latter and for the identification of the few who develop permanent hypothyroidism.

A longitudinal study of valproate free fraction in the specific age group at greatest risk for febrile convulsions (children below 3 years)

The behavior of the free fraction of valproic acid (VPA) was evaluated during long-term treatment of 24 children (9-18 months of age) with febrile convulsions. A series of relevant hematological parameters was monitored for the entire observation period (12 months). VPA plasma levels ranged from 54.3 +/- 26 to 66.6 +/- 32.8 micrograms/ml. The unbound fraction of the drug was determined in tears, which has been shown to be the best practical indicator of the free portion of an anticonvulsant drug, and ranged from 5.1 +/- 4.0 to 6.1 +/- 4.3 micrograms/ml. The tear/plasma ratio (and hence the free/total ratio) ranged from 9.3 to 9.7, in agreement with literature data. No significant variations of VPA plasma and tear levels, and therefore of the tear/plasma ratios, were ever observed. The hematological data revealed no significant alterations during the entire observation time, although some of the variables did fluctuate. Side effects were mild and temporary. The present report indicates that VPA has no particular toxic effect in young children treated for the prevention of febrile convulsions.

A comparison of the bioavailability of two carbamazepine preparations (200 and 400 mg tablets)

A 2-week open, randomized, crossover study was conducted in epileptic patients on chronic therapy, who took either carbamazepine (CBZ) 200 or CBZ 400 mg tablets. The oral dose was 1200 or 1600 mg/day, according to individual needs. There was no difference in absorption or steady-state levels between the two preparations. The new galenic preparation of CBZ will help the neurologist to reduce the number of tablets taken by severe epileptic patients, with no risk but only benefits for the subjects.

The penetration of phenobarbital in generalized and focal penicillin-induced epileptic brain of the cat

The penetration of phenobarbital (PB) into cerebral tissue was determined in cats rendered epileptic by parenteral penicillin and in cats with focal penicillin-induced epilepsy. The results were compared with those from normal controls. In both kinds of experimental models of epilepsy, PB penetration was impaired, although a gradual and progressive accumulation of the drug in the brain tissue was observed in all three groups of cats (binding occurring from time 30 min on). Similar to the events with other substances, such as carbamazepine, the prolonged epileptic activity may have contributed to the impaired penetration of PB, because of severe metabolic alterations secondary to seizures. The present data confirm previous reports indicating that epileptic seizures alter the pharmacokinetics of drugs.

Brain atrophy, peripheral neuropathy and folic acid deficiency

A woman with peripheral neuropathy and cerebral atrophy, both secondary to a selective folic acid deficiency caused by severe gastrointestinal disturbances, was given folic acid replacement therapy, which improved her clinical, blood and neurophysiological status.

Calibration of a heated transcutaneous carbon dioxide electrode to reflect arterial carbon dioxide

The CO2 measured by a heated skin surface electrode is greater than arterial CO2. In this study we (1) determined the magnitude of this difference retrospectively, (2) adjusted the calibration of the heated transcutaneous CO2 electrode to reflect this difference, and (3) tested the validity of the calibration procedure prospectively. The retrospective study consisted of 252 simultaneous arterial and transcutaneous measurements on 38 infants and children (age range, 1 day to 6 yr). A linear regression analysis showed PtcCO2 = 1.61 X PaCO2 - 0.01 mmHg, r = 0.90 (p less than 0.0001). Because the intercept was virtually zero, we subsequently changed the calibration procedure by dividing the transcutaneous electrode reading by 1.61. The prospective study consisted of 269 more simultaneous arterial and transcutaneous measurements from 57 consecutive infants and children (age range, 1 day to 18 yr) using this calibration procedure. Regression analysis showed PtcCO2 = 1.02 X PaCO2 - 2.3 mmHg, r = 0.96 (p less than 0.0001). Thus, we found that the transcutaneous CO2 electrode, using this technique, reliably predicted the arterial CO2.

Carbamazepine versus diphenylhydantoin in the treatment of myotonia

A double-blind controlled trial was performed on 6 patients affected with Steinert's disease in order to evaluate the efficacy of two different dosages of diphenylhydantoin (PHT, 200 and 300 mg/day) and carbamazepine (CBZ, 600 and 800 mg/day) on the myotonic afterdischarge. Both dosages of PHT and CBZ induced a significant improvement of myotonia. For PHT a trend towards decreased efficacy is pointed out at toxic or at high dosages.

Long-term therapy with carbamazepine: effects on nerve conduction velocity

Peripheral nerve function was evaluated in 30 epileptic patients on chronic therapy with carbamazepine (CBZ) and 20 healthy controls. The electrophysiological data indicated a mild progressive reduction of both motor and sensory conduction velocity in the patients on long-term treatment with the drug. The impairment of nerve function paralleled the duration of therapy (i.e. 1 through 3 years). CBZ plasma levels were constantly within the therapeutic range. Folic acid levels were below normal in about 50% of the subjects. In the absence of other evidence, the hypothesis cannot be excluded that folate deficiency may have played some role in the development of the peripheral nerve dysfunction.

Cerebellar impairment following acute nontoxic administration of phenytoin in rat

In awake paralyzed Wistar rats, the following effects of an acute nontoxic dose of phenytoin (PHT) on different parameters of cerebellar electrical activity were evaluated: spontaneous discharge rate of single Purkinje cells (P-cells), field potentials, and responses of P-cells generated by electrical stimulation of a forelimb nerve. Variations of the response of single neurons located in the inferior olive were also studied, in order to assess the effects of PHT on this precerebellar relay station. The drug was administered orally and plasma and cerebellar levels regularly estimated. The results indicate that an acute, nontoxic dose of PHT is associated with an increase of P-cell firing rate. This finding is supported by the analysis of the frequency distribution of interspike intervals, and by the field potentials, P-cell, and olivary responses induced by stimulation of a radial nerve. In addition, it was observed that the increase in P-cell firing was mainly depending upon a higher activity of the climbing fibers. The increase in the response of P-cells and olivary cells was correlated with plasma and cerebellar drug levels. The conclusion was reached that PHT increases the cerebellar cortical activity through two mechanisms: (a) by acting directly on the cerebellar P-cell; and (b) indirectly by acting on the origin of climbing fibers at the inferior olive nucleus.

Normal brain distribution of carbamazepine in cat penicillin focal epilepsy

Carbamazepine (CBZ) brain distribution was studied in cats rendered epileptic by penicillin topically applied on neocortex. CBZ penetration into the focus did not differ significantly from penetration into the other areas of the brain, with the drug rapidly entering the cerebral tissue (peak at 30 min). As no difference was found between CBZ brain concentrations at 15 and 90 min, substantial early binding of the drug was confirmed in this experimental model of epilepsy. As CBZ was able to decrease rapidly the spike frequency of the penicillin focus, it may be speculated that it was also able to prevent the metabolic alterations associated with severe epileptogenesis that would have caused an impaired CBZ brain distribution.

Continuous transcutaneous oxygen and carbon dioxide monitoring in the pediatric ICU

The transcutaneous partial pressures of carbon dioxide (PtcCO2) and oxygen (PtcO2) were measured with heated electrodes in 18 hemodynamically stable pediatric ICU patients and these data were compared to simultaneously measured arterial oxygen and carbon dioxide tensions. There was a significant degree of correlation (p less than 0.001) between the skin surface CO2 and O2 and their corresponding arterial tensions. These data defined values for PtcCO2 and PtcO2 indices in the pediatric patient without cardiovascular complications as PtcCO2 index = 1.6 +/- 0.2 and the PtcO2 index = 0.84 +/- 0.18 (PtcCO2 index = PtcCO2/PaCO2 and PtcO2 index = PtcO2/PaO2). The authors found the monitoring of skin surface gases a reliable technique to monitor arterial gas tension in hemodynamically stable patients.

Brain uptake of carbamazepine in the cat

Carbamazepine (CBZ) was determined by EMIT assay in plasma, cerebrospinal fluid (CSF), and brain samples of cats after administration of the drug (40 mg/kg, i.p.). Plasma and CSF levels increase in a parallel manner from time 0 to 90 min after completion of injection, indicating a passive transport from one body fluid to the other. Brain levels reach a steady state at 15 min, with no significant difference being found between the concentrations at 15, 30, 60, and 90 min postinjection; this indicates that substantial early binding occurs in the brain. Since peak CSF concentrations occur at 90 min, concomitant with those for plasma, while brain levels are already high at 15 min, it is likely that CBZ enters the two compartments by independent mechanisms.

Anticonvulsant drugs determined by EMIT in spiked brain samples: a correlation with HPLC values

Phenobarbital (PB), diphenylhydantoin (PHT) and carbamazepine (CBZ) levels were determined in spiked rat brain homogenates by means of the EMIT assay, and these were compared with results obtained by high-pressure liquid chromatography (HPLC). The extraction procedure of the three drugs was identical for both methods, with minor modifications for EMIT (no addition of internal standard; reconstitution with the buffer used in routine plasma level analysis). Correlation coefficients between the data obtained by EMIT and HPLC were extremely good (PB, 0.90-0.98; PHT, 0.92-0.98; CBZ, 0.93-0.99). The results indicate that the EMIT system can detect PB, PHT, and CBZ in brain tissue with good accuracy, although HPLC remains the most accurate and proven method available for research purposes.

The free fraction of valproic acid in tears, saliva, and cerebrospinal fluid

Valproic acid (VPA) was determined by EMIT assay in plasma, tears, saliva, and cerebrospinal fluid (CSF) of patients with epilepsy. Closer correlation was shown between tear/plasma and tear/CSF ratios than between saliva/plasma and saliva/CSF ratios. The VPA CSF/serum ratio was in good agreement with data in the literature. Salivary levels were extremely erratic, while those for tears were much more reliable. Determination of VPA in tears is therefore the best method of studying the VPA free fraction in those cases in which investigations of protein binding of the drug are necessary.

Transcutaneous measurements of carbon dioxide partial pressure in sick neonates

The authors measured the partial pressure of carbon dioxide transcutaneously (PtcCO2) in 15 sick newborns and compared the PtcCO2 to simultaneously measured partial pressure of arterial carbon dioxide (PaCO2). The PtcCO2 values reflected changes in the PaCO2 values. A linear regression on 106 paired PtcCO2 and PaCO2 values produced a correlation coefficient of 4 = 0.91 with a slope of 1.89 and a y-intercept of --9.4. The authors found the measurement of PtcCO2 to be a clinically useful method of continuously following the trend of PaCO2.

Diphenylhydantoin and primidone in tears

Diphenylhydantoin (PHT) and primidone (PRM) were determined by the EMIT technique in the plasma, tears, saliva, and CSF of epileptic patients. Results indicate for PHT that tear values are more strictly correlated than are the saliva values to plasma and CSF concentrations. As for PRM, the data obtained show great interindividual variability of concentration in the different body fluids--in agreement with the wide range of both protein binding and half-life of this drug.

Ethosuximide in tears, saliva, and cerebrospinal fluid

Ethosuximide (ESM) was determined by the EMIT technique in tears, saliva, cerebrospinal fluid (CSF), and plasma of epileptic subjects. CSF/plasma, saliva/plasma and saliva/CSF ratios were in good agreement with gas-liquid chromatography (GLC). The tears/plasma ratio was not significantly different from the saliva/plasma ratio, although the standard deviation was higher in the latter. These data indicate that ESM can be determined in a quantitatively similar manner in both saliva and tears by EMIT.

Psychotic onset of multiple sclerosis

A case is reported of a woman in whom acute manic attacks were followed later in life by neurological signs of multiple sclerosis, thus suggesting a possible correlation between the two clinical entities.

Carbamazepine-10,11-epoxide determined by EMIT carbamazepine reagent

Carbamazepine-10,11-epoxide (CBZ-OX) was determined in physiological solutions by means of EMIT carbamazepine reagent. It was recognized as 12 to 20% of the total amount, the cross-reaction being higher at lower CBZ-OX concentrations. A correction for CBZ-OX is necessary when one wants to correlate EMIT carbamazepine values with gas-liquid chromatography values. However, this correction is relevant only for body fluids other than plasma, since the unbound fraction of CBZ-OX would greatly influence the ultrafiltrate serum ratios.

Neonatal screening in Italy for congenital hypothyroidism and metabolic disorders: hyperphenylalaninemia, maple syrup urine disease and homocystinuria

A multiple screening program to establish the frequency of congenital hypothyroidism (CH), phenylketonuria (PKU), maple syrup urine disease (MSUD), homocystinuria and hypertyrosinemia in endemic and sporadic goitrous regions of Italy is being carried out. Valine, methionine, leucine, isoleucine, tyrosine and phenylalanine, eluted from a single spot and separated by column chromatography, are measured, using whole blood adsorbed on filter paper. CH is detected by RIA assay of TSH eluted from dried blood spot. A cut-off of 100 microU/ml for TSH is used providing a recall rate of 0.38%. Out of 116,000 newborn infants screened for aminoacidopathies (since 1974), 16 PKU patients, 3 affected by MSUD, 2 homocystinuric babies have been detected. Out of 25,400 newborn infants screened for CH, 5 patients were affected by permanent CH and 29 by transient hyperthyrotropinemia. Thus PKU shows a frequency of 1:7,200 newborn infants, and permanent congenital hypothyroidism 1:5,080. The coordination of screening programs for congenital metabolic diseases in a single central unit allows:--the unification of the input of samples and output of data in a single data bank;--a minimization of the physical and psychological stress to the patients and their families;--and a more satisfactory cost/benefit ratio.

Immunoreactive trypsin on dried-blood spots as a possible neonatal test for cystic fibrosis. (I. Evaluation of the method and preliminary field trial)

A method for blood spot immunoreactive trypsin (IRT) determination suitable for neonatal mass screening, and the preliminary steps towards its large-scale application are described. The method showed a highly significant correlation between blood spot and plasma values, and a study of plasma reference values in a population of 1,050 newborn infants demonstrated a log-normal distribution with a mean IRT concentration of 238.3 ng/ml. The results and their implications for neonatal mass screening are discussed.

Acquired ocular-motor apraxia and right-sided cortical angioma

A case of acquired ocular-motor apraxia featured by failure in voluntary initiation of lid closure, horizontal and vertical eye movements is reported. Electrographic and neuropsychological assessment pointed out several signs referable to bilateral frontal and right parietal lobe involvement, confirmed by neuroradiological finding.

Effects of propylthiouracil and methylmercaptoimidazole on thyroglobulin synthesis

The effect of 6-propyl-2-thiouracil (PTU), and 1-methyl-2-mercaptoimidazole (MMI) on thyroglobulin (Tg) biosynthesis has been studied in vivo and in vitro. In vivo experiments were performed in rats treated for 20 days with PTU or MMI, analyzing soluble and particulate, cold and 125I-labelled, Tg. Thyroglobulin biosynthesis was also investigated by in vitro experiments, incubating thyroid tissue with labelled amino acid and carbohydrate in the presence of antithyroid compounds. It has been found that in vivo antithyroid agents decrease the amount of soluble Tg and increase the proportion of particulate Tg. Tg from treated animals is poorly iodinated being mainly represented by its 12S subunit. In vitro studies demonstrate that PTU and MMI inhibit Tg biosynthesis which is impaired in the polypeptide synthesis as well as in carbohydrate chains addition. Thus the inhibition of the hormonogenetic processes induced by antithyroid treatment leading to a depressed iodinating activity also appears to be related to a significant impairment of the production of the Tg molecule, the specific iodine acceptor.

Tears as the best practical indicator of the unbound fraction of an anticonvulsant drug

Phenobarbital and carbamazepine concentrations were determined by the EMIT technique in tears, saliva, cerebrospinal fluid (CSF), and plasma of patients with epilepsy. Closer correlation was shown between tear/plasma and tear/CSF ratios than between saliva/plasma and saliva/CSF ratios for the two agents. The phenobarbital CSF/serum ratio was in good agreement with data in the literature, and the higher ratio found for carbamazepine may be caused by an EMIT assay cross-reaction for the free fraction of carbamazepine-10,11-epoxide. In our hands, tears seem to represent the best practical indicator of the unbound fraction of an anticonvulsant drug, and the noninvasiveness of the method makes it specifically useful in pediatric neurology.

Plasma and cerebrospinal fluid tryptophan in multiple sclerosis and degenerative diseases

Tryptophan and competing neutral amino acid levels were found to be diminished in the plasma of patients with multiple sclerosis and degenerative diseases, the greatest decrease being of tryptophan. Cerebrospinal fluid tryptophan was decreased in multiple sclerosis and motor neurone disease, while leucine and valine were increased. These changes might lead to decreased synthesis of brain serotonin and brain proteins. The ratio between neutral amino acids and tryptophan might be used as an ancillary test in the screening of degenerative diseases.

A month-by-month long-term study on carbamazepine:clinical, EEG and pharmacological evaluation

Carbamazephine plasma levels were monitored for a twelve-month period in twenty epileptic patients. Seizure frequency decreased remarkably on inclusion of the drug in the therapy and attainment of plasma levels of 7-9 microgram/ml. A faster breakdown rate in children was confirmed, while carbamazepine-10, 11-epoxide was present for carbamazepine levels above 4-5 microgram/ml. EEG tracings did not show substantial modifications; this variable was thus considered to be of little value in assessing the clinical picture. Side-effects were minimal. Carbamazepine is increasingly becoming the drug of first choice in the management of both generalized and partial epilepsy, while better and more rapid results are obtained in monotherapy.

Post-convulsive spinal epidural haematoma in ankylosing spondylitis

A case of post-convulsive spinal spidural haematoma in a patient with ankylosing spondylitis is presented. As acute tetraplegia developed, surgery was performed with finding of blood clots in the extradural space from C6 to D8. Lethal evolution due to late referral to medical care stresses the need for prompt decompression of the injured spine.

Complicated optic atrophy (Bher's disease) associated with epilepsy and amino acid imbalance

A case of Behr's disease (complicated optic atrophy) associated with epilepsy and with imbalance of the free amino acid pool in plasma and cerebrospinal fluid, quite similar to that identified in patients with hereditary ataxias, is reported. The latter finding stands for a closer correlation between the two clinical entities.

Effects of levodopa alone and in combination with dopa-decarboxylase inhibitors on plasma renin activity in patients with Parkinson's disease

Plasma renin activity (PRA) of patients with Parkinson's disease was measured in recumbency, upright position, and after frusemide administration. The results show that the renin responses to both stimuli are significantly reduced as compared with those obtained in a group of normal subjects, while recumbent PRA levels of Parkinsonism patients are not significantly lower than those found in recumbent normal subjects. Levodopa treatment, alone or in combination with two different dopa-decarboxylase inhibitors, benserazide and carbidopa, does not modify the renin response to posture or to frusemide. Although the reduced activity of the renin-angiotensin system can play some role in the genesis of orthostatic hypotensive episodes encountered in patients with Parkinsonism, the greater incidence of orthostatis hypotension in patients treated with levodopa seems to be unrelated to any effect of this drug on the renin release.