Albert Larbrisseau

Neurologic Crises in Hereditary Tyrosinemia

Hereditary tyrosinemia results from an inborn error in the final step of tyrosine metabolism. The disease is known to cause acute and chronic liver failure, renal Fanconis syndrome, and hepatocellular carcinoma. Neurologic manifestations have been reported but not emphasized as a common problem. In this paper, we describe neurologic crises that occurred among children identified as having tyrosinemia on neonatal screening since 1970. Of the 48 children with tyrosinemia, 20 (42 percent) had neurologic crises that began at a mean age of one year and led to 104 hospital admissions. These abrupt episodes of peripheral neuropathy were characterized by severe pain with extensor hypertonia (in 75 percent), vomiting or paralytic ileus (69 percent), muscle weakness (29 percent), and self-mutilation (8 percent). Eight children required mechanical ventilation because of paralysis, and 14 of the 20 children have died. Between crises, most survivors regained normal function. We found no reliable biochemical marker for the crises (those we evaluated included blood levels of tyrosine, succinylacetone, and hepatic aminotransferases). Urinary excretion of delta-aminolevulinic acid, a neurotoxic intermediate of porphyrin biosynthesis, was elevated during crises but also during the asymptomatic periods. Electrophysiologic studies in seven patients and neuromuscular biopsies in three patients showed axonal degeneration and secondary demyelination. We conclude that episodes of acute, severe peripheral neuropathy are common in hereditary tyrosinemia and resemble the crises of the neuropathic porphyrias.

The Andermann syndrome: agenesis of the corpus callosum associated with mental retardation and progressive sensorimotor neuronopathy.

Andermann et al. described in 1972 an autosomal recessive inherited syndrome which associates agenesis of the corpus callosum, mental deficiency, and a peripheral motor deficit. We had the opportunity to study in detail 15 patients affected by this syndrome. As in the cases previously reported, the families of these children all originated from Charlevoix County and the Saguenay-Lac St-Jean area in the Province of Quebec. Clinically, these patients have a characteristic facies and moderate mental retardation associated with a progressive motor neuropathy leading to loss of ambulation by adolescence and progressive scoliosis. In 13 of these 15 patients, neuroradiological investigation has shown either total or partial agenesis of the corpus callosum. In every patient in whom these tests were done, sensory nerve action potentials were absent and motor nerve conduction velocities reduced. We also found neurogenic abnormalities both on EMG and neuromuscular biopsies. These abnormalities are similar to those described in Friedreichs ataxia and in hereditary motor and sensory neuropathy type II, although in our patients the motor deficit is much more severe than in these diseases. The pathogenesis of the peripheral nervous system involvement is still unknown since there have so far been no autopsy studies of this syndrome.

Congenital malformations associated with maternal use of valproic acid.

Two children born with birth defects after intrauterine exposure to valproic acid are reported. The mothers took the drug throughout pregnancy as sole treatment for primary generalized epilepsy. The first baby showed facial dysmorphism, arachnodactyly and triphalangeal thumbs. The second had facial dysmorphism, severe laryngeal hypoplasia, tracheomalacia and an aberrant innominate artery that caused tracheal compression. A left superior vena cava, abnormal pulmonary lobulation, and unilateral hydronephrosis were also found at autopsy. Valproic acid has probable teratogenic potential in humans but the number of reported cases is few and the spectrum of anomalies is broad so it is not possible to delineate a definite fetal valproate syndrome.

Intermittent treatment of febrile convulsions with nitrazepam.

Intermittent oral or rectal administration of diazepam for the prophylactic treatment of febrile convulsions has given results comparable to the continuous use of phenobarbital while limiting side effects and risks of toxicity. Since we believe that nitrazepam is a better anticonvulsant than diazepam, we performed a study to evaluate the effectiveness of this medication in the prophylactic treatment of febrile convulsions. Nitrazepam was given only when the children had fever and almost exclusively in children with a high risk of recurrence (less than 12 months of age at first convulsion; atypical convulsion; one or several previous convulsions). Thirty one children with a high risk of recurrence received nitrazepam. The rate of recurrence in this group was 19.3% after a follow-up of 16 months, compared to 45.8% in 24 children who also had a high risk of recurrence but in whom the parents refused the medication or gave it inadequately (p less than 0.05). Fifty one children with a low risk of recurrence also were evaluated and followed for at least 12 months (mean 15.4 months). Six were treated with nitrazepam, mostly because of parental anxiety, and none had a recurrence; of the 45 untreated children in this group, 6 (13.6%) had another convulsion. These results show the efficiency of nitrazepam in the prophylactic treatment of febrile convulsions.

Efficacy and safety of lacosamide as an adjunctive therapy for refractory focal epilepsy in paediatric patients: a retrospective single-centre study.

AIM Lacosamide is an antiepileptic drug approved for the treatment of focal epilepsy in adult patients. The aim of this observational study was to review our centres experience with lacosamide and to characterize its effectiveness and tolerability as an adjunctive antiepileptic drug in a retrospective cohort of children with refractory focal epilepsy. METHODS We retrospectively reviewed the medical records of 22 patients who received lacosamide from November 2009 to April 2014 at the CHU Ste-Justine, University of Montreal. Treatment responders were defined as children with a ≥50% reduction in seizure frequency compared to baseline, and this was determined three months after the initiation of treatment and at the last follow-up visit. RESULTS We included 14 boys and eight girls with a mean age of 12.9 years (SD: 5.2; range: 5.2-20.7 years) at the initiation of treatment. The average length of follow-up was 11.9 months. Patients had previously received an average of 7.5 antiepileptic drugs. The mean number of concomitant antiepileptic drugs was 2.3. The mean initial and maintenance doses were 2.9 and 8.4 mg/kg/d, respectively. Thirteen (59%) and ten (45%) patients were responders after three months of treatment and at the last follow-up visit, respectively. One became seizure-free. Adverse effects were reported in 11 patients and none were severe. Responders and non-responders were identical with respect to all studied parameters except gender, with the proportion of responders being greater in girls than in boys (75% vs 29%; p=0.035). CONCLUSION Our study adds evidence that lacosamide appears to be a safe and effective adjunctive therapy for children with refractory focal epilepsy.

Benign familial neonatal convulsions.

Benign familial neonatal convulsions are a rare genetic seizure disorder inherited as an autosomal dominant trait. They consist of brief episodes of seizures, recurring during the first few days or weeks of life in otherwise normal babies; their prognosis is good. We report a family in which at least 12 members in three generations presented with this condition; they all had an excellent outcome.

Café-au-lait Macules and Neurofibromatosis Type 1: A Review of the Literature

BACKGROUND The first sign of neurofibromatosis type 1 (NF1) in a child is often the presence of multiple café-au-lait macules. Although previous studies reported that almost individuals with multiple café-au-lait macules will eventually develop NF1 based on clinical criteria, recent studies and clinical observations suggest that a significant percentage of them do not have NF1. METHODS We conducted the first systematic review of the literature on the prevalence of definitive NF1 among patients referred for isolated café-au-lait macules, searching more precisely for the proportion of those patients who do not have NF1. Because we now know that the presence of café-au-lait macules and freckling might not distinguish between NF1 and other conditions such as Legius syndrome, definitive NF1 was defined as the presence of café-au-lait macules with or without freckling plus one of the following: Lisch nodules, neurofibroma, plexiform neurofibroma, bone dysplasia, optic pathway glioma, or familial history of NF1. RESULTS Six articles reported sufficient data to meet our inclusion criteria. Grouping all studies together, we found that 19.5% to 57.1% of all patients with isolated café-au-lait macules did not have a diagnosis of NF1 after follow-up or genetic testing. CONCLUSION A significant portion of the patients presenting with isolated café-au-lait macules at initial consultation might not have NF1. Genetic testing could help guide the follow-up of those patients, but further evidence is required to make recommendations.

Meningitis and Brain Abscess Due to Clostridium Perfringens And Clostridium Paraputrificum Following Orbital Trauma

An 8 year old boy developed cerebral abscess and purulent meningitis due to Clostridium perfringens and Clostridium paraputrificum after trauma to the left orbit. The patient made a satisfactory recovery with surgical treatment and antibiotic therapy. A review of the literature revealed that meningitis due to Clostridia is rare and usually related to penetrating trauma, and that penetrating trauma to the orbit is associated with significant central nervous system morbidity.