Glutamate dehydrogenase deficiency in patients with olivopontocerebellar atrophy

Deficiency of glutamate dehydrogenase appears to be associated with a chronic progressive degenerative disorder manifesting parkinsonian extrapyramidal features, ataxia, supranuclear oculomotor dysfunction, a peripheral neuropathy and, in some cases, amyotrophy. The clinical features resemble those of the Dejerine-Thomas type of olivopontocerebellar atrophy. The data suggest autosomal dominant inheritance with low penetrance. Measurement of leukocyte glutamate dehydrogenase should be routinely performed in the evaluation of newly diagnosed or atypical cases of parkinsonism.

Parkinson's disease in 65 pairs of twins and in a set of quadruplets

Among 43 monozygotic (MZ) and 19 dizygotic (DZ) pairs in which an index case had definite Parkinson's disease (PD), only one MZ pair was definitely concordant for PD. When pairs with questionable clinical features were included, 4 of 48 MZ and 1 of 19 DZ pairs were concordant. The frequency of PD in MZ cotwins of index cases with PD was similar to that expected in an unrelated control group matched for age and sex. Although we were unable to identify a single environmental agent, we conclude that the major factors in the etiology of PD are nongenetic.

Meige syndrome: relief on high-dose anticholinergic therapy

A patient with Meige syndrome associated with spasmodic torticollis was treated with benztropine mesylate (Cogentin) at doses of 12-16 mg daily. Marked suppression of both oromandibular dystonia and the torticollis was obtained. Mild impairment of recent memory was the major side effect. Peripheral anticholinergic side effects were controlled by the concomitant administration of ambenonium chloride (Mytelase) 15 mg daily.

Homer's moly identified as Galanthus nivalis L.: physiologic antidote to stramonium poisoning

The antidotal properties of certain naturally occurring medicinal plants against central nervous system intoxication appear to have been empirically established in ancient times. Homer, in his epic poem, the Odyssey, described a plant, "moly," used by Odysseus as an antidote against Circe's poisonous drugs. Centrally acting anticholinergic agents are thought to have been used by Circe to induce amnesia and a delusional state in Odysseus' crew. We present evidence to support the hypothesis that "moly" might have been the snowdrop, Galanthus nivalis, which contains galanthamine, a centrally acting anticholinesterase. Thus the description of "moly" as an antidote in Homer's Odyssey may represent the oldest recorded use of an anticholinesterase to reverse central anticholinergic intoxication.

Effects of dopamine depletion on rotational behavior to dopamine agonists

The contralateral rotation to various dopamine agonists was determined in rats with unilateral lesions of the left nigrostriatal pathway both with and without dopamine depletion caused by dopamine synthesis inhibition. The rotation to drugs possessing D-2 dopamine agonist activity alone was greatly diminished by dopamine depletion. In contrast, the rotation induced by drug possessing D-1 dopamine agonist activity (either D-1 alone or D-1 plus D-2) was affected to a much lesser extent by dopamine depletion.

Pergolide-induced circling in rats with 6-hydroxydopamine lesions in the nigrostriatal pathway

In rats with a unilateral 6-hydroxydopamine lesion of the nigrostriatal system we compared the behavioral effects of pergolide with those of L-dopa, bromocriptine, and lergotrile. In this animal model of parkinsonism, doses of 0.25 mg per kilogram pergolide (free base) induced vigorous circling for 24 hours. Pergolide was more potent than bromocriptine or lergotrile. Pretreatment with alpha-methylparatyrosine nearly abolished the effects of bromocriptine, markedly diminished the effects of lergotrile, and only partially diminished the effects of pergolide. These findings suggest that pergolide should be more effective than bromocriptine in the treatment of parkinsonism.

Management of patients who fail to respond to levodopa therapy

Nonresponders to levodopa therapy include patients with parkinsonism who fail to respond to a well-tolerated therapeutic dosage, those who lose an initially positive response, and those who develop severe and dose-limiting side effects. Initial failures may be due to inadequate dosage, drug interactions or inaccurate diagnosis. Loss of response suggests the need for a thorough medical evaluation. Severe side effects such as nausea and vomiting may be managed with adjuvant agents; dystonia and a variety of paradoxical responses may preclude the use of levodopa, and amantadine or anticholinergic agents should be considered as alternatives.

Potentiation by deprenil of 1-dopa induced circling in nigral-lesioned rats

1-Deprenil, a potent inhibitor of type B monoamine oxidase, was a weak inhibitor of 3H-dopamine uptake as well as a weak releasing agent for previously accumulated 3H-dopamine in rat neostriatal tissue slices. In similar experiments d-amphetamine as approximately 100 times as potent as 1-deprenil as a releasing agent. When deprenil (20 mg/kg IP) was given to rats with a unilateral 6-hydroxydopamine lesion of the substantia nigra, it brought about a moderate but long-lasting ipsilateral rotational behavior. 1-Dopa (20-40 mg/kg, IP) by itself caused a considerably stronger rotation in the opposite direction (contralateral). When 1-dopa was given to rats 1 hr after 1-deprenil, there was a considerably greater contralateral rotation than after 1-dopa alone. Clorgyline, a type A monoamine oxidase inhibitor, which by itself at 20 mg/kg caused no rotation, also potentiated the contralateral rotation seen after 1-dopa (5-20 mg/kg). In contrast, d-amphetamine, which by itself caused ipsilateral rotation, failed to potentiate the rotation after 1-dopa. Possible mechanisms for these observations will be discussed.

The relationship between loss of dopamine nerve terminals, striatal [3H]spiroperidol binding and rotational behavior in unilaterally 6-hydroxydopamine-lesioned rats

The relationship between the destruction of dopamine-containing nerve terminals, specific binding of [3H]spiroperidol and contralateral rotation in response to L-DOPA, was studied in rats with unilateral lesions of the nigrostriatal dopamine (DA) system, induced by intracerebral injections of the neurotoxin 6-hydroxydopamine (6-OHDA). Animals with significant rotational behavior in response to L-DOPA had both a greater amount of specific binding of [3H]spiroperidol in the lesioned striatum compared to the non-lesioned striatum, and at least 90% destruction of DA terminals in the lesioned striatum (less than 10% of control uptake). The nonrotators to L-DOPA had considerably less destruction of DA terminals and no significant increase in specific binding on the lesioned side. The data from this study suggest that before L-DOPA is effective as an inducer of contralateral rotational behavior, there must be both unilateral damage to the DA terminals greater than 90%, and increased specific binding.

Twin study of Parkinson disease

Zero concordance for Parkinson disease was found in the first 12 monozygotic twin pairs examined in an ongoing twin study. One co-twin (subject without Parkinson disease) had essential tremor, another had cerebral vascular disease, and a third was an alcoholic. Cigarette smoking appeared to be less frequent in the probands than in the co-twins (11.9 versus 16.1 pack-years). There was also evidence of premorbid personality differences between probands and co-twins dating back to late adolescence or early adult years. These preliminary findings suggest that genetic factors do not play a major role in the etiology of Parkinson disease and point to a prodromal onset of the disease as early as late adolescence or early adult life.

Amino acids in rat neostriatum: alteration by kainic acid lesion

Unilateral stereotaxic injection of 10 nmol of the glutamomimetic substance, kainic acid, into the rat striatum caused permanent, significant decreases in the levels of glutamate (40--50%), aspartate (35--40%), taurine (20--30%) and GABA (60--70%). There were initial, transient decreases in serine, glycine and alanine which returned to normal values within 16--32 days after injection. Glutamine levels were not altered in lesioned striatum. This coincided with a 55% increase in glutamine synthetase activity in the lesioned striatum compared either to the non-injected striatum or controls injected with saline. The high affinity uptake of choline by synaptosomal preparations of lesioned striatum was decreased by 70% compared to controls whereas that of glutamate/aspartate was either unchanged or somewhat on a per mg protein basis. This latter point may be illusory in that, because of widespread neuronal destruction, the total 'synaptosomal' protein obtained from the lesioned striata was only about 50% that from control tissue. The biochemical data are consistent with the histological and behavioral effects of kainic acid administration. The unchaning glutamine levels and increase in glutamine synthetase activity are consistent with the widespread gliosis and the lack of change in glutamate/aspartate high affinity uptake is consistent with a sparing of afferent terminals. The large decrease in glutamate and aspartate is consistent with hypotheses concerning the intraneuronal localization of a major pool of these amino acids, especially in GABAergic neurons. The decrease in taurine suggests that a portion of this amino acid in striatum is probably associated with neurons destroyed by kainic acid. The bulk of the taurine, however, is therefore associated either with glial cells or the afferents to the striatum.

A survey of tardive dyskinesia in psychiatric outpatients

The authors found a high prevalence--43.4% of tardive dyskinesia in a sample of psychiatric outpatients, a population previously thought to be at nominal risk for development of this syndrome. There was no significant relationship between the presence of dyskinesia and age, sex, years of neuroleptic use, or various organic factors. The effects of dentures and of drug combinations are discussed, and it is noted that structured scales of dyskinesia and videotope recordings are important tools in diagnosing and following the course of dyskinesia.

Note on the scoliosis of Parkinsonism

A lateral deviation of the spine and a corresponding tendency to lean to one side was found in 19 and 21 consecutive unoperated patients with Parkinsonism encountered in an outpatient clinic. The direction of postural deviation correlated significantly with the laterality of the major signs and symptoms of Parkinsonism. The phenomenon appears to be analogous to the postural asymmetries produced in experimental animals by unilateral lesions of the nigroneostriatal pathways.