Clinical Studies | Movement Disorders


CLINICAL STUDY 1 — Treatment and Prognosis of the Therapeutic Effect of L-Dopa in Dystonia Musculorum Deformans

—Mel’nichuk PV, Minich LN.

Clinico-biochemical examinations of 55 patients suffering from various clinical forms of deforming myodystonia were performed. L-dopa was used in 47 cases. A correlation between the therapeutic effect and the level of phenylacetylglutamine excretion was revealed. The increase of the phenylacetylglutamine excretion was an evidence of a positive result of the treatment that was noted in 36 patients (77%). A resistance to the drug was observed in cases when the phenylacetylglutamine excretion did not exceed its normal level. The quantitative determination of phenylacetylglutamine in the daily portion of the urine can be used as a prognostic test of the therapeutic efficacy of l-dopa in patients with deforming myodystonia. PMID: 484133

(phenylalanine is the precursor to tyrosine, which in turn is the precursor to l-dopa)

CLINICAL STUDY 2 — Experience with L-Dopa Treatment of Children with Dystonia Musculorum Deformans and Dystonic Hyperkineses in Infantile Cerebral Palsy

—Bondarenko ES, Malyshev IuI.

Nineteen children with dystonia musculorum deformans and dystonic hyperkineses were treated by l-dopa. A mild positive effect was obtained in 6 children, a considerable positive effect in 9 children. A more marked positive effect was obtained in children with dystonia musculorum deformans. The results indicate the efficiency of l-dopa in the treatment of dystonia musculorum deformans and dystonic hyperkineses against the residual organic background. The advisability of 2-3 month long courses of therapy with l-dopa 2-3 times a year is discussed. Some patients may need a continuous therapy with maintenance doses of the drug. PMID: 4072505

(phenylalanine is the precursor to tyrosine, which in turn is the precursor to l-dopa)

CLINICAL STUDY 3 — Deficit of Short-Term Memory in Newly Diagnosed Untreated Parkinsonian Patients: Reversal after L-Dopa Therapy

—Marini P, Ramat S, Ginestroni A, Paganini M. – 1st Neurological Clinic, Neurological and Psychiatric Science Department, University of Florence, Florence, Italy

We assessed the effect of pathology and l-dopa therapy on attention, working memory, and executive functions, in newly diagnosed Parkinson’s disease patients. Twenty-one consecutive outpatients who met the criteria for de novo Parkinson’s disease, and were naive for l-dopa therapy, were observed for the first time. All patients underwent clinical and neuropsychological evaluations (cognitive decline, memory, executive control). Each patient was reevaluated on standard l-dopa therapy. Serial Position Curves showed an increased primacy effect (5.18+/-2.07) and a decreased recency effect (13.35+/-5.51). These findings normalized after l-dopa therapy (3.50+/-1.72 and 16.20+/-3.09 respectively). The effect of l-dopa on working memory is discussed. PMID: 14598078

(phenylalanine is the precursor to tyrosine, which in turn is the precursor to l-dopa)

CLINICAL STUDY 4 — Restless Legs – A Much Neglected Syndrome

—Ulfberg J, Jönsson R, Lindberg E, Nyström B, Mallon L. – Lungkliniken, Akademiska sjukhuset, Uppsala

Ekbom’s syndrome, or ‘restless legs syndrome’ (RLS), not only causes symptoms in the extremities during waking hours, but also sleep disturbance and daytime fatigue. Although the prevalence of RLS has been estimated to be 1-5%, the condition is probably underdiagnosed and undertreated. Its onset may occur at any age, and there may be long periods of remission, but the condition is generally chronic. In its primary form, there is often a family history of the disorder suggestive of an autosomal dominant mode of inheritance, where the results of EMG (electromyography) and nerve conduction studies are normal. In secondary forms, clinical signs and laboratory evidence of an associated abnormality are present. The most characteristic symp of RLS is the spontaneous occurrence of paraesthesia or dysaesthesia during waking hours. The symptoms of RLS are worse or exclusively present during rest, and are partially or temporarily relieved by activity. About 80 per cent of RLS patients also suffer from ‘periodic limb movements during sleep’ (PLMS), which may cause microarousals during sleep. The diagnosis of RLS is based on characteristic clinical criteria, and the sleep disturbance is diagnosed polysomnographically. L-dopa and clonazepam have been found successful in the treatment of primary RLS, though lifelong treatment is often necessary. PMID: 10193123

(phenylalanine is the precursor to tyrosine, which in turn is the precursor to l-dopa)

CLINICAL STUDY 5 — Phenylethylamine Metabolism in Tourette’s Syndrome

—Bornstein RA, Baker GB, Carroll A, King G, Ashton S. – Department of Psychiatry, Ohio State University, Columbus, USA

Beta-phenylethylamine, phenylalanine, and phenylacetic acid were examined in 24-hour urine samples and/or plasma samples obtained from 28 medication-free patients with Tourette’s syndrome and 20 control subjects matched for age and education. Statistical analyses revealed that Tourette patients had lower plasma phenylalanine and urinary free beta-phenylethylamine compared with the controls, but did not differ on urinary total levels of phenylacetic acid. Fifty percent of the Tourette patients had a urinary beta-phenylethylamine level that was lower than the lowest control subject. In addition, urinary beta-phenylethylamine levels were inversely related to several scores from the Tourette Syndrome Global Scale. These data suggest that abnormalities in synthesis or metabolism of beta-phenylethylamine may be involved in the etiology of some patients with Tourette’s syndrome. PMID: 2136393

CLINICAL STUDY 6 — Treatment of Multiple Sclerosis with Lofepramine, Image – Phenylalanine and Vitamin B12: Mechanism of Action and Clinical Importance: Roles of the Locus Coeruleus and Central Noradrenergic Systems

—C. Loder, Corresponding Author Contact Information, E-ma, J. Allawib and D. F. Horrobinc – Laurelhill Business Park, Stirling, Scotland, UK

In a randomized, placebo-controlled double-blind trial a combination of lofepramine, phenylalanine and vitamin B12 was found to be effective in relieving the symptoms of multiple sclerosis (MS). The effect occurred within 2–4 weeks, and improved all types of symptoms in all types of MS. The combination was also effective in relieving symptoms in patients with chronic pain and chronic fatigue. We hypothesize that the action of this combined therapy may relate to activation of the noradrenergic locus coeruleus/lateral tegmentum (LC/LT) system which has the potential to influence the functioning of large areas of the brain and spinal cord. PMID: 4146521

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