Impairment of consciousness induced by valproate treatment following neurosurgical operation

Eight patients, who underwent neurosurgery for various supratentorial lesions presented unexplained impairment of consciousness during the first post-operative days. These states ranged from stupor to deep coma, and two patients had an emergency re-exploration. All these patients were receiving the usual dosage (1000 to 1500 mg per day) of Valproic acid (VPA). The treatment had been initiated either several weeks or months previously in 4 cases, and was thus well tolerated, or the day before surgery in the 4 other cases. EEG recordings displayed diffuse abnormalities, delta waves and/or high voltage triphasic complexes, that led to the diagnosis of VPA intolerance and drug withdrawal. Then full clinical recovery and EEG clearing occurred within 1 to 5 days. VPA intolerances are wellknown but remain exceptional, about 1 case per 100.000. In our neurosurgical population, however, the rate was higher, approximately 2%. Wide areas of blood brain barrier destruction may contribute to the higher frequency of this easily reversible cause of post-operative stupor or coma.

A case of acute encephalopathy after iohexol lumbar myelography

A case of acute encephalopathy after lumbar myelography is reported in a female aged 26 years. Fourteen hours after the procedure, the patient developed coma (GCS 6) and had generalized slowing of EEG activity. This state lasted about 12 h, followed by gradual and full recovery.

Enhanced endogenous ornithine concentrations protect against tonic seizures and coma in acute ammonia intoxication

Pretreatment of mice with 5-fluoromethylornithine (5FMOrn), a selective inactivator of ornithine aminotransferase, diminishes the accumulation of ammonia in the brain after administration of ammonium acetate, and antagonizes ammonia-induced fatal tonic extensor convulsions. In about 50% of the treated animals the loss of the righting reflex and coma is prevented. Presumably these effects are based on the enhancement of urea formation by the increased liver ornithine concentrations. However, since brain ornithine concentrations are greatly enhanced by 5FMOrn, it is not excluded that ornithine has direct effects on cellular events involved in ammonia-induced seizure generation, even though 5FMOrn had no anticonvulsant properties in a series of established animal seizure models, including N-methyl-D,L-aspartate-induced convulsions. NMDA receptor antagonists are capable of preventing death, but do not protect against the generation of coma and tonic extensor convulsions in ammonium acetate intoxicated mice. Since no evidence was found for ammonia-induced glutamate release from rat hippocampus, there is no convincing evidence for the idea that the tonic convulsions are mediated by NMDA receptors. L-Methionine-D, L-sulfoximine (MSO)-induced seizures can be partially antagonized by pretreatment with 5FMOrn. However, the effect is considerably smaller than against ammonia-induced convulsions, although at the time of seizure onset brain ammonia levels of MSO-intoxicated mice were lower than in the animals receiving ammonium acetate. This suggests that MSO-convulsions are not entirely due to the elevation of brain ammonia concentrations, even though MSO administration mimics effects of ammonia on cortical inhibitory neuronal interactions.(ABSTRACT TRUNCATED AT 250 WORDS)

Haemodialysis treatment in phenobarbital intoxication in infancy

Haemodialysis treatment was performed in a comatose infant who was 9 months old. At the beginning of haemodialysis plasma phenobarbital concentration was found to be 120 micrograms/ml. The constant low flux haemodialysis lowered the plasma phenobarbital concentration to 64.2 micrograms/ml and haemodialysis was terminated at the end of six hours. The patient recovered fully after haemodialysis session. This case indicates that haemodialysis is an effective and successful treatment method in phenobarbital intoxication also in infancy.

Early parenteral nutrition in patients unconscious because of acute drug poisoning

The author studied the clinical and laboratory effects of early parenteral nutrition (EPN) in patients who were comatose as a result of acute drug poisoning. All patients were unconscious at the time of admission and entry into the study and received our usual conservative therapy for the first 24 hours. Alternate patients received an EPN solution containing amino acids and glucose. Volume, composition, and caloric content of the EPN solution were calculated separately for each patient according to weight and height nomograms. It was found that the group receiving EPN (n = 46) normalized their nitrogen balance sooner and demonstrated a consistent decrease in their creatine phosphokinase level. Serum amino acid values in patients treated with EPN did not change significantly during the treatment trial. The control group (n = 40) demonstrated a significantly lower serum amino acid concentration on the third day of treatment (p < .001), had significantly more pneumonias (p < .05), and their hospitalization time was significantly longer (.01 < p < .05) than the EPN group. There were significantly fewer instances of disseminated intravascular coagulation in the group receiving EPN (p < .05).

Extrapyramidal syndrome responsive to dopaminergic treatment following recovery from central pontine myelinolysis

A 52-year-old woman developed severe hyponatremia following treatment for hypertension with chlorthalidone. Rapid correction of hyponatremia resulted in coma, quadriplegia and hypopnea compatible with central pontine myelinolysis. She recovered with residual facial hypomimia, bradykinesia, cogwheel rigidity and coarse resting tremor, responding to dopaminergic treatment. Her symptoms and signs, which are quite similar to idiopathic Parkinson's disease, are still responsive to treatment 7 years after onset.

Successful treatment of severe refractory sulfonylurea-induced hypoglycemia with octreotide

OBJECTIVE

To test the clinical use of octreotide in the treatment of sulfonylurea-induced hypoglycemia.

RESEARCH DESIGN AND METHODS

A case is reported of sulfonylurea-induced hypoglycemic coma in a nondiabetic subject, which was complicated by relapse of hypoglycemia after resuscitation with intravenous dextrose. Subcutaneous octreotide, 50 micrograms 12 hourly, suppressed stimulated endogenous insulin secretion, thereby preventing a further recurrence of hypoglycemia.

RESULTS

No adverse effects of treatment were observed.

CONCLUSIONS

These results suggest a significant role for octreotide as an adjunct to intravenous dextrose in the management of severe and refractory cases of sulfonylurea-induced hypoglycemia.

[Neurotoxic role of glycocolle and derivatives in transurethral resection of the prostate]

72-year-old patient underwent an elective transurethral resection of the prostate (TURP) performed with a spinal anaesthesia. The irrigation solution contained glycine at a concentration of 15 g.l-1. The patient's level of consciousness deteriorated over the next 4 hours. He went in an areflexic coma with pupillary areflexia and left mydriasis. The diagnosis of TUR syndrome was substantiated by a sodium blood concentration of 98 mmol.l-1, an osmotic gap of 48 mosmol.kg-1 and blood ammonia at 415 mumol.l-1. To investigate the pathophysiological role of glycine and its metabolites, their concentrations were measured by chromatography and spectrometry in plasma and CSF 8, 24 and 48 hours postoperatively. Glycine and its metabolites (serine, alanine, glyoxylic acid and glycolic acid) accumulated during the postoperative period in both blood and CSF. The central nervous system is in direct contact with these neurotropic compounds. Glycine is an inhibitory neurotransmitter, whereas glyoxylic acid and glycolic acid are considered as to be neurotoxic.

[Acute poisoning due to oral intake of an organic solvent]

We report a case of paint thinner intoxication by oral intake, with loss of consciousness, upper gastrointestinal injuries, renal failure, rhabdomyolysis and cervical plexus injury. The clinical picture was similar to other cases reported in the literature.

Carbamyl phosphate synthetase-1 deficiency discovered after valproic acid-induced coma

Valproic acid induced coma is presented in an adult patient without a history of metabolic disease. Liver biopsy revealed a reduction in activity of carbamyl phosphate synthetase-I, an enzyme obligated for transformation of ammonia to urea in the urea cycle. After recovery CT scan follow-up showed marked cerebral atrophy which did not exist prior to the state of coma. Risk factors are discussed.

[Anesthesia of the brain stem after a retrobulbar block. Description of 2 cases]

The Authors report two cases of central nervous system complications after retrobulbar block. These complications have a 0.044% incidence in 4500 subsequent cases of retrobulbar blockade studied from 1981 to 1990. The Authors attribute the respiratory arrest and coma to direct access of the anesthetic to the central nervous system along the subdural space in the optic nerve sheath.

[Acute encephalopathy in ethylene glycol poisoning]

Poisoning with ethylene glycol is the most frequent poisoning in our country. Acute encephalopathy during this poisoning may be a cause of important diagnostic difficulties, especially in the initial phase of the poisoning, due to the variety of symptoms and signs. Three cases of this poisoning are reported. All patients were erroneously referred and admitted to neurological hospital department. It is postulated that in each case of coma of unknown aetiology with signs suggesting damage to the brain stem and hyperventilation arterial blood gasometric examination should be done and blood and urine should be taken for toxicological investigations. In the treatment of glycol poisoning the most important task is to correct metabolic acidosis and to apply early dialysis treatment in serious intoxication.