Letter: Monosodium glutamate intolerance in children

Epidemiology and management of essential tremor in children

Essential tremor (ET) is a common, often familial, movement disorder characterized by tremor of the limbs, head, and voice. Epidemiological surveys indicate that up to 5% of the adult population has ET, and 5-30% of adults with ET report symptom onset during childhood. There is, however, little published regarding ET in the pediatric population, and no prospective studies targeted specifically to children. Retrospective studies from subspecialty movement disorder clinics indicate that childhood-onset ET is usually hereditary, begins at a mean age of 6 years, and affects boys three times as often as girls. While ET occasionally results in disability during childhood, only one-quarter of children seeing a neurologist for ET require pharmacotherapy. Small case series suggest that propranolol is effective in approximately 50% of children with ET, but controlled treatment trials are lacking.

Shuddering attacks-report of four children

Shuddering attacks are recognized as an uncommon benign disorder occurring during infancy or early childhood. It is necessary to distinguish these episodes from epileptic seizures. The attacks seem to involve shivering movements occurring daily for several seconds without impairment of consciousness. According to the criteria for benign myoclonus of early infancy, both shuddering attacks and benign myoclonus of early infancy should be regarded as having the same nosologic entity. I studied the pathophysiology of shuddering attacks in four children between 8 and 14 months of age using a video-electroencephalographic monitoring system. In one patient the frequency of shuddering movements, which was read as contamination of the electromyography on electroencephalography during attacks, seemed to be almost the same as that as of essential tremor. Shuddering attacks have decreased in number or disappeared in all four patients, but one exhibited mild abnormalities on magnetic resonance imaging and had relatives with epilepsy, and another had a flattened sella turcica. Although previous reports suggest that these movements are benign and needless investigations should be avoided, a problem related to the development of the nervous system may be present in children with shuddering attacks.

Myoclonus and epilepsies

The possible associations of myoclonic phenomenae, progressive or non-progressive encephalopathies and epileptic features are reviewed, with special emphasis on pediatric age. This leads to recognize the following five groups of conditions: (1) Myoclonus without encephalopathy and without epilepsy; (2) Encephalopathies with non-epileptic myoclonus; (3) Progressive encephalopathies presenting myoclonus seizures of epileptic syndromes (Progressive myoclonus epilepsies); (4) Epileptic encephalopathies with myoclonic seizures; (5) Myoclonic epilepsies. Within the first group, which also includes physiologic myoclonus, a more thorough description of "Benign sleep myoclonus of newborn" and "Benign myoclonus of early infancy" is given. Characteristics of group 2 are "Kinsbourne Syndrome" and certain types of "Hyperekplexia" which pose interesting differential diagnosis with stimulus-sensitive epilepsies. In group 3, the concept of progressive encephalopathies is stressed. The fourth group refers to severe epilepsies, mainly on infancy and childhood, which lead to mental retardation irrespective of their aetiology. Group 5 comprises the true myoclonic epilepsies, differentiating syndromes recognized as idiopathic--such as "Benign myoclonic epilepsy of infancy" and "Juvenile myoclonic epilepsy"--from those which are cryptogenic and carry a more cautious prognosis--as "Cryptogenic myoclonic and myoclonoastatic epilepsies" and "Severe myoclonic epilepsy of infancy". Other epileptic syndromes not usually considered as myoclonic epilepsies, but presenting sometimes as myoclonic seizures, are finally referred.

Chinese restaurant syndrome: a review

CRS is a benign, self-limited process that has an excellent prognosis for immediate and rapid recovery. While questions remain about exactly who is susceptible, how much MSG is needed, and even whether MSG is the sole etiologic agent, there appears to be little reason to embark on an extensive workup and treatment regimen with a presumptive diagnosis of MSG intoxication. Rather, knowledge of CRS and recognition of its associated signs and symptoms and its clinical course are important.

Some varieties of food intolerance in psychiatric patients: an overview

Foods may cause mental and behavioural symptoms by means of a variety of mechanisms. Food allergy is only one of many of these. The paper presents a brief overview of evidence, as of early 1982, concerning cerebral allergy, food addiction, the hypoglycaemias, caffeinism, hypersensitivity to chemical food additives, reactions to vasoactive amines in foods, and reactions attributed to neuropeptides formed from foods as causes of mental symptoms, with particular reference to psychiatric patients. It is concluded that although much work in this field remains to be done, enough is already known to benefit patients now if available knowledge is applied. An individual-centred environmental approach, extending beyond dietary factors if necessary, is recommended as more likely to help than a group-centred paradigm-based approach to treatment.

Flavor potentiators

This review provides extensive presentation and evaluation of data relative to flavor potentiation, including the historical, chemical, organoleptic, metabolic, physiological, and consumptive properties of the commonly available flavor potentiators, which are primarily monosodium glutamate and 5'-nucleotides. In addition, their food occurrences, mode of action, manufacturing procedures, and methods of analyses will be discussed. Also, attention will be given to miscellaneous compounds that possess flavor potentiating properties.

Infantile bilateral striatal necrosis. Clinical and morphological report of a case and a review of the literature

A case of infantile bilateral striatal necrosis (IBSN) is reported, the first one found in Scandinavia. Extensive clinical and laboratory investigations did not reveal any evidence of a neurometabolic disease. By computed tomography (CT) degeneration of putamen of either side was detected. The neuropathologic findings included extensive bilateral destruction of the striatum and pallidum and degeneration of the substantia nigra and tegmental nuclei. In the damaged regions, accumulations of cells containing sudanophilic lipids were found and Alzheimer type II glial cells, which were also seen in the cortex. On the basis of the clinical picture and the destruction of nerve cells in particular areas of the brain, in the present case and previously published cases of IBSN, the possible role of glutamate and other excitotoxic transmitters in the pathogenesis of the disease is discussed.