[Follow-up of a cohort of patients after substitution of phenytoin for phenytoin sodium in an epilepsy center]. / Suivi d'une cohorte de patients après substitution de la phénytoïne pour de la phénytoïne sodique dans un centre de lutte contre l'épilepsie.

In March 2012, the French Health Products Safety Agency interrupted the commercialization of di-hydan (phenytoin). It was replaced by diphantoïne (phenytoin sodium) and prescribers were informed that posology was equivalent for both products. We conducted a retrospective study of phenytoinemia and clinical effects comparatively for these two drugs in a population of adult patients with epilepsy admitted in La TEPPE. Forty-four patients were included. Mean age was 47.6 years. Phenytoinemia significantly decreased after substitution (17.14mg/L with di-hydan versus 12.17mg/L with diphantoïne, P<8 10(-6)). Moreover an increase in post substitution posology of diphantoïne was noticed (264.77mg/L with di-hydan versus 274.73mg/L with diphantoïne), although not significant (P=0.11). Increase of seizures was non-significant (P = 0.09). The decrease of phenytoinemia was probably due to the difference of composition between the drugs: a 100mg di-hydan tablet contains 100mg of phenytoin whereas a 100mg diphantoïne tablet contains 92mg. The specific non-linear kinetics of phenytoin reinforces this difference. A prospective study could better evaluate the risk of substituting di-hydan with diphantoïne.

Comparison of twice- and three times daily tiagabine for the adjunctive treatment of partial seizures in refractory patients with epilepsy: an open label, randomised, parallel-group study.

UNLABELLED: A multicentre, open label, randomised, parallel group study compared the efficacy, tolerability and safety of two dosing regimens, t.i.d. and b.i.d., of tiagabine as an adjunctive therapy for the treatment of refractory patients with partial seizures. A total of 347 patients were randomised and treated (175 t.i.d. and 172 b.i.d.). Each group was administered the same daily dose of tiagabine incremented stepwise during a 12-week fixed-schedule titration period to a target dose of 40 mg/day. The patients were followed for a further 12-week flexible continuation phase. A significantly greater number of patients in the t.i.d. group completed the fixed schedule titration period (81.4% versus 73.1%; 95% CI of odds ratio = 0.331, 0.970; p = 0.038). The proportion of responders (patients showing at least a 50% decrease in all-seizure frequency from baseline) was similar for both groups (42.3% for b.i.d. and 47.1% for t.i.d.) during the last 8 weeks of the flexible phase and seven (4.0%) patients in the b.i.d. group were seizure-free compared to 14 (8.1%) patients in the t.i.d. group. Adverse events were of similar incidence in both groups, and mainly occurred during the fixed schedule titration period; they were mainly mild and CNS-related with somnolence being the most frequently reported. CONCLUSION: Tiagabine was effective as add-on treatment of refractory partial seizures. Although both regimens appear to offer a similar efficacy and safety profile, significantly more patients completed the study in the t.i.d. group compared to b.i.d., probably as a consequence of a lesser tolerability when high doses are given undivided. These results confirm that a slow titration and appropriate adjustment of dosing are essential conditions to ensure optimal use of tiagabine.

[Disorders of voluntary motor activity and lesions of caudate nuclei]. / Perturbations de l'activité motrice volontaire et lésions des noyaux caudés.

Three clinical cases are reported, resulting in apathy, uninterest, flattened affect and lack of initiative for usual daily activities. Intellectual performances were normal and there was no depression. This syndrome was reversible when patients were stimulated. Stereotyped behaviors resembling compulsions were frequent. One of the patients presented with prolonged akinetic episodes reversible by verbal stimulation. CT and MRI showed bilateral lesions, mainly in and around the head of the caudate nucleus. Such behavioral disorders have been termed psychic akinesia or athymhormia syndrome, suggesting that the patients suffered from a loss of drive and motivation. The lesions involved bilaterally the globus pallidus, the striatum or the frontal lobe. Recently, anatomical findings have shown several circuits through the basal ganglia additional to the motor circuit. The caudate nucleus receives inputs from the prefrontal and limbic cortex. These inputs are transmitted to the globus pallidus, then to the thalamus and ultimately return to the dorsolateral prefrontal, lateral orbitofrontal and anterior cingulate areas. Lesions in any part of these cortico-subcortical loops may be responsible for a dramatic behavioral syndrome, emphasizing their functional specificity in drive. However, a procedural learning impairment in neostriatal dysfunction could possibly explain the disorders observed in our patients.

[Infarction of the pons, neurosyphilis and HIV infection]. / Infarctus pontique, syphilis nerveuse et infection par le VIH.

A 31-year old patient presented a right hemiparesis related to a left basis pontis infarction. Laboratory investigations revealed both neurosyphilis and HIV infection. The patient was treated with two courses of penicillin and recovered from hemiparesis. The occurrence of strokes due to syphilitic arteritis in AIDS is emphasized.

[Primary lymphoma of the central nervous system. Multiple remission with corticosteroid therapy]. / Lymphome primitif du système nerveux central. Rémissions multiples sous corticoïdes.

A primary T-cell lymphoma of the central nervous system was diagnosed at autopsy in a 73-year-old woman. The course of the illness was made of multiple neurological episodes: hypersomnia, palsies of cranial nerves, aphasia, hemiparesis, epileptic fits during 4 years, with fast recoveries under corticosteroid therapy. CT scan and MRI abnormalities were also dramatically improved by the treatment.

[Recurrent peripheral neuropathy caused by thallium poisoning]. / Neuropathie périphérique récidivante par intoxication au thallium.

A 28-years old woman, working as a secretary, developed a rapidly progressive paraplegia with burning pain in the lower limbs. She recovered within 4 months but relapsed shortly after she was discharged. There was flaccid tetraplegia, associated with hyperalgesia of the limbs, diffuse muscle atrophy, blindness and alopecia. The patient needed respiratory assistance for 2 months. Bilateral optic neuropathy and paraparesis persisted after a 17 months follow-up. The clinical picture suggested thallium poisoning, which was confirmed by high thallium concentration in plasma and urine. The most likely cause was accidental poisoning with rodenticides.

[Normal pressure hydrocephalus and lumbar neurinoma]. / Hydrocéphalie à pression normale et neurinome lombaire.

A 76-year-old man presented with gait disturbances, mental deterioration and urinary incontinence. CT and MRI suggested a normal pressure hydrocephalus. Because of a raised protein content of CSF, a spinal MRI was performed and revealed a lumbar neurinoma. The patient improved after removal of the neurinoma and ventricular derivation.