Extrapontine myelinolysis in infancy: report of a case

Osmotic myelinolysis is a rare, acute, demyelinating process that involves the pons (central pontine myelinolysis) and other locations of the central nervous system (extrapontine myelinolysis). Central pontine myelinolysis is described in children, usually associated with rapid correction of hyponatremia. Other conditions, such as hypernatremia and hyperglycemia, have also been reported as being responsible for pontine myelinolysis. Extrapontine myelinolysis in childhood is very rare and presents in a wide variety of locations. We report a patient who developed extrapontine myelinolysis in the cerebellum during treatment of hyponatremic dehydration. This is the first case reported during infancy.     

Extrapontine myelinolysis after surgical removal of a pituitary tumour

Salvesen R. Extrapontine myelinolysis after surgical removal of a pituitary tumour.
Acta Neurol Scand 1998: 98: 213–215. Munksgaard 1998.
Extrapontine myelinolysis is a rare and serious disorder characterized by patches of demyelination in certain areas of the brain. Common sites of involvement are the basal ganglia and the thalamus. The patient most often presents with behavioural abnormalities, including mutism, and extrapyramidal symptoms and signs. The diagnosis is established by magnetic resonance imaging. It usually carries a grave prognosis. The pathogenesis seems to be related to profound hyponatremia that is corrected with infusions of saline. We report a case that underwent surgical removal of a pituitary tumour and subsequently was treated with desmopressin. Probably due to an overdose of this antidiuretic hormone, she became obtunded and was found to have profound hyponatremia. This was corrected with infusions of saline, mostly isotonic. She later developed mental disorientation and mutism, and magnetic resonance imaging demonstrated myelinolysis in the basal ganglia. In the course of several months, she has made some recovery, though still demonstrating some memory deficit.     

Lateral pontine and extrapontine myelinolysis associated with hypernatremia and hyperglycemia

Efforts to understand and prevent pontine and extrapontine myelinolysis have focused on the correction of hyponatremia, but controversy persists. We report a woman who presented in hyperosmolar diabetic coma with hypernatremia (169 mEq/l) and hyperglycemia (954 mg/dl). Plasma sodium rapidly increased to 188 mEq/l before gradually returning to normal. She remained obtunded and died 21 days later. Autopsy showed widespread, symmetrical demyelination involving the subcortical white matter, corpus callosum, anterior commissure, extreme, external, and internal capsules, fornix, thalamus, cerebellum, and lateral pons. The central pons and lateral geniculate nuclei were uninvolved. This case illustrates that lateral pontine and extrapontine myelinolysis can be associated with hypernatremia and hyperosmolality. In both hypo- and hypernatremic states, the significant event may be an increase in serum sodium or serum osmolality of sufficient rapidity and magnitude.     

Extrapontine myelinolysis in a pediatric case of diabetic ketoacidosis and cerebral edema

Central pontine and extrapontine myelinolysis are characterized by symmetric demyelination following rapid shifts in serum osmolality, although in extrapontine myelinolysis, demyelination is confined to the supratentorial compartment. We present a case of extrapontine myelinolysis in a 17-year-old female that occurred in the setting of diabetic ketoacidosis, cerebral edema, mannitol therapy, and meningitis. The rate of correction of this patient's glucose and electrolyte levels was within well-accepted limits. Extrapontine myelinolysis is rare in pediatric patients: there are only 12 reports of extrapontine myelinolysis in children under age 20 years and no pediatric cases of extrapontine myelinolysis or central pontine myelinolysis associated with diabetic ketoacidosis. We review the published cases of extrapontine myelinolysis and examine the underlying etiologies and electrolyte disturbances that characterize these cases. This case expands the list of conditions in which extrapontine myelinolysis occurs to include pediatric patients with complicated diabetic ketoacidosis, emphasizing the importance of sudden osmolar shifts in the genesis of this disorder.     

Extrapontine myelinolysis caused by electrolyte imbalance during the management of suprasellar germ cell tumors Report of two cases

Extrapontine myelinolysis (EPM) is caused by marked fluctuation of the serum electrolyte level. Patients with suprasellar germ cell tumors frequently present with diabetes insipidus, which is often aggravated by administration of steroid hormone. In addition, cisplatin-based chemotherapy is sometimes accompanied by marked serum electrolyte fluctuation because it needs massive hydration to prevent renal damage. Two children with suprasellar germ cell tumors in whom EPM developed secondary to profound hyponatremia and was rapidly corrected are described. The central pons was spared in both cases. Clinically the children showed transient neurological deficits including confusion, pseudobulbar palsy, and deterioration of consciousness. MRI demonstrated bilateral symmetrical, high-signal-intensity (HSI) lesions on T2-weighted images (T2WI) at the basal ganglia and adjacent cerebral cortex. Follow-up T1WI a few months later revealed newly developed HSI lesions in the basal ganglia. The patients gradually improved, but the neurological deficits did not completely disappear. During the perioperative management of suprasellar germ cell tumors, EPM should be considered when a patient has a significant electrolyte imbalance and neurological deficits, especially confusion and pseudobulbar palsy. Received: 19 September 1997 Revised: 16 December 1997     

Changes of auditory brainstem responses in electrolyte-induced myelinolysis in rats. Role of hyponatremia and hypernatremia

Electrolyte-induced myelinolysis was produced in rats to evaluate electrophysiological derangement in the brainstem. Auditory brainstem responses (ABRs) were used to assess the brainstem function. Rats treated with hypertonic saline for 2 days had normal interpeak latencies in ABRs. Rats treated with vasopressin-induced hyponatremia alone and those with hypertonic saline after 3 days of hyponatremia had significantly prolonged interpeak latencies between waves II-III and III-IV in ABRs. These prolongations indicate electrophysiological derangement of the upper pons and mesencephalon in hyponatremic rats as well as in rats with hyponatremia followed by hypernatremic myelinolysis. In view of these data, hyponatremia may be a prerequisite for electrolyte-induced myelinolysis and electrolyte derangements such as hyponatremia, and rapidly correcting hypernatremia may be the cause of electrolyte-induced myelinolysis in rats.     

Extrapontine myelinolysis with parkinsonism after rapid correction of hyponatremia: high cerebrospinal fluid level of homovanillic acid and successful dopaminergic treatment

Extrapontine myelinolysis (EPM) is a demyelinating process of the brain. We report the case of an 11-year-old girl who developed EPM with parkinsonism. Magnetic resonance imaging revealed demyelinating patterns in the basal ganglia without central pontine lesions. The cerebrospinal fluid levels of homovanillic acid and 5-hydroxyindoleacetic acid were high at the time of onset and normalized upon complete recovery from extrapyramidal symptoms after a dopaminergic treatment. We speculated that demyelination of nerve fibers containing dopamine receptors in the striatum might be a main cause of these symptoms.     

Polymyositis with severe facial involvement

Summary A case of imflammatory myopathy with faciopharyngoproximal distribution is reported. It is very unusual for facial weakness to be a major feature in polymyositis, but when other muscles are involved the clinician should be stimulated to look for an inflammatory myopathy. Marked improvement may be achieved as a result of corticosteroid therapy.

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Zusammenfassung Wir berichten über einen Fall einer entzündlichen Myopathie mit fazio-pharyngo-proximaler Beteiligung. Fazialisparese als wichtigstes Zeichen ist ungewöhnlich im Rahmen einer Polymyositis. Die besondere Verteilung der Muskelschwäche, welche unsere Patientin aufwies, ist eine klinische Variante, bei welcher immer nach einem entzündlichen Prozeß gesucht werden muß, da eine Steroidtherapie hier mit Erfolg angewendet werden kann.

     

重型颅脑损伤后高钠血症的原因分析及防治对策

目的探讨重型颅脑损伤后高钠血症的病因、发生机制,对患者预后的影响及防治对策。方法回顾性分析136例重型颅脑损伤后发生高钠血症患者的临床资料和临床转归,并对所得结果进行统计学处理。结果出现高钠血症38例。高钠血症与24h出入量、GCS评分关系密切,并发高钠血症的重型颅脑损伤患者病死率明显增高。结论医源性脱水过多及下丘脑损害致水电解质失衡是高钠血症的主要原因,密切监测血钠浓度、及时调整水电解质平衡、积极治疗原发病是防治重型颅脑损伤后高钠血症的关键。     

Renal sympathoinhibition induced by hypernatremia: involvement of A1 noradrenergic neurons

Several findings suggest that A1 noradrenergic neurons in the caudal ventrolateral medulla (CVLM) contribute to body fluid homeostasis and cardiovascular regulation. Recently we demonstrated that the renal vasodilation induced by infusion of hypertonic saline (HS) depends on the integrity of the A1 neurons. Here we determined the effect of lesions of these neurons on the inhibition of the renal sympathetic nerve activity (RSNA) induced by HS infusion. All experiments were performed in Wistar rats (280-350 g). A1 neurons were lesioned by microinjections of antidopamine-beta-hydroxylase-saporin (6.3 ng in 60 nl) into the CVLM (n=5), whereas sham rats received microinjections of free saporin (1.3 ng in 60 nl, n=10). Two weeks later, rats were anesthetized (urethane 1.2 g/kg, iv), and instrumented for recording of arterial pressure and RSNA. In sham rats, HS infusion (3 M NaCl, 0.18 ml/100 g bw, iv) induced a transient (相似文献   

Awareness of number in children with severe and profound learning difficulties: three exploratory case studies

This paper reports on exploratory work investigating how children with severe and profound learning difficulties register an awareness of small quantities and how they might use this information to inform their understanding. It draws on studies of typically developing children and investigates their application to pupils whose response to conventional mathematical tasks are often limited because they lack relevance and interest. The responses of the three pupils to individualized learning contexts mirror the progression suggested in the literature, namely from awareness of number to simple actions using number cues to problem‐solving behaviour.     

Assistive technology for promoting choice behaviors in three children with cerebral palsy and severe communication impairments

A technology-based program to promote independent choice behaviors by three children with cerebral palsy and multiple disabilities was assessed. The program was based on learning principles and assistive technology (i.e., customized input devices/sensors, personal computers, screening of preferred stimuli according to a binomial criterion). The first purpose of the present study was to provide the participants with a new set-up of assistive technology and to allow them to choose among three categories (i.e., food, beverage and leisure), and to request a specific item out of four in each category, adopting a procedure that minimized (according to a conditional probability criterion) unintentional choices. The second aim of the study was to carry out the effects of the program on detectable mood signs (i.e., happiness index). The study was conducted according to an ABAB sequence with a subsequent post intervention check for each participant. The results showed an increase of engagement and of the happiness index during intervention phases. Psychological as well as educational implications were discussed.