Alberto Fois

High rate of mosaicism in tuberous sclerosis complex.

Six families with mosaicism are identified in a series of 62 unrelated families with a mutation in one of the two tuberous sclerosis complex (TSC) genes, TSC1 or TSC2. In five families, somatic mosaicism was present in a mildly affected parent of an index patient. In one family with clinically unaffected parents, gonadal mosaicism was detected after TSC was found in three children. The detection of mosaicism has consequences for genetic counseling of the families involved, as changed risks apply to individuals with mosaicism, both siblings and parents. Clinical investigation of parents of patients with seemingly sporadic mutations is essential to determine their residual chance of gonadal and/or somatic mosaicism, unless a mosaic pattern is detected in the index patient, proving a de novo event. In our data set, the exclusion of signs of TSC in the parents of a patient with TSC reduced the chance of one of the parents to be a (mosaic) mutation carrier from 10% to 2%. In the five families with somatic mosaicism, the parent was given the diagnosis after the diagnosis was made in the child.

Celiac disease and epilepsy in pediatric patients

Among 783 patients referred to our institute with different types of seizures as presenting symptom, systematic evaluation of antigliadin and antiendomysial antibodies in the serum has identified nine in whom jejunal biopsy has subsequently confirmed the diagnosis of celiac disease (CD). In three of them brain imaging showed the presence of calcified areas in the occipital region. They had complex partial seizures (CPS), associated in two with transient episodes of blindness. In another patient with CPS and generalized tonic-clonic seizures (GTCS) progressive multifocal cerebral calcifications were noted. In the other six patients with CPS and/or GTCS cerebral calcifications were absent. Symptoms of CD in all these cases were either not previously taken into account, or they were very mild or completely absent. In a group of 36 patients with clinically manifest CD, regular follow-up, and good compliance with the dietary regimen, no clinical seizures were reported. The pathogenetic mechanism and the relationship between epilepsy and an early diagnosis and treatment of celiac disease are discussed.

Vagus nerve stimulation for drug-resistant epilepsy in children and young adults

We present our experience with the use of intermittent vagal nerve stimulation in 13 patients with medically intractable epilepsy. A surgical approach, with the exception of callosotomy, was impossible. The age range was 6-28 years (median 17 years). In all patients the epilepsy was severe and in six of them was symptomatic. Seven patients had Lennox-Gastaut syndrome, one epilepsy with myoclonic-astatic seizures, four localization-related and one symptomatic generalized epilepsy. The length of the follow-up averaged 22 months (range 8 months-3 years). Of the 13 patients, five (38.4%) had a 50% or more reduction in the number of seizures compared with preimplantation. Of these patients, one with a localization-related epilepsy had a 90% reduction as well as a significant improvement in alertness. Three patients showed no improvement with regard to the number of seizures but there was an improvement in alertness and, in one case in hyperactivity. Some seizure types responded better than others did: complex partial seizures with secondary generalization and atonic seizures. All our responsive patients improved in the first 2 months of VNS activation and only one case with further improvement was observed after this period. Considering the severity of the epilepsy the results can be considered satisfactory. We think that this treatment appears to be a safe adjunctive therapy for children and adults with medically and surgically intractable epilepsy.

Diagnosis of Angelman syndrome: clinical and EEG criteria

In order to evaluate which diagnostic criteria can be indicative for an early diagnosis of Angelman syndrome (AS), 144 children with severe epilepsy and mental retardation were evaluated. In 10 of them the diagnostic criteria indicated by Williams were present. Of the remaining 134 patients we were able to diagnose one 15-year-old patient with AS, on the basis of the EEG findings, even though the typical clinical features of the syndrome were absent. In all patients the diagnosis of AS was confirmed by fluorescent in situ hybridization (FISH) in 10 patients and by methylation analysis in one patient. AS is very likely when both typical clinical and EEG findings are present. Nevertheless, it must be considered in all patients affected by severe epilepsy and mental retardation, when the EEG pattern is sufficiently indicative, and FISH and/or molecular analysis should be performed even in absence of typical clinical signs.

Novel and recurrent tyrosine aminotransferase gene mutations in tyrosinemia type II.

Abstract Tyrosinemia typeII (Richner-Hanhart syndrome, RHS) is a disorder of autosomal recessive inheritance characterized by keratitis, palmoplantar hyperkeratosis, mental retardation, and elevated blood tyrosine levels. The disease results from deficiency in hepatic tyrosine aminotransferase (TAT). We have previously described one deletion and six different point mutations in four RHS patients. We have now analyzed the TAT genes in a further seven unrelated RHS families from Italy, France, the United Kingdom, and the United States. We have established PCR conditions for the amplification of all twelve TAT exons and have screened the products for mutations by direct sequence analysis or by first performing single-strand conformation polymorphism analysis. We have thus identified the presumably pathological mutations in eight RHS alleles, including two nonsense mutations (R57X, E411X) and four amino acid substitutions (R119W, L201R, R433Q, R433W). Only the R57X mutation, which was found in one Scottish and two Italian families, has been previously reported in another Italian family. Haplotype analysis indicates that this mutation, which involves a CpG dinucleotide hot spot, has a common origin in the three Italian families but arose independently in the Scottish family. Two polymorphisms have also been detected, viz., a protein polymorphism, P15S, and a silent substitution S103S (TCG→TCA). Expression of R433Q and R433W demonstrate reduced activity of the mutant proteins. In all, twelve different TAT gene mutations have now been identified in tyrosinemia typeII.

A randomized trial of oral betamethasone to reduce ataxia symptoms in ataxia telangiectasia.

No controlled studies exist regarding the pharmaceutical reduction of ataxia symptoms in ataxia telangiectasia (A‐T). In a multicenter, double‐blind, randomized, placebo‐controlled crossover trial, oral betamethasone (BETA) and placebo were compared in terms of their reduction of ataxia symptoms as assessed with the International Cooperative Ataxia Rating Scale (ICARS). In this study of 13 A‐T children, betamethasone reduced the ICARS total score by a median of 13 points in the intent‐to‐treat population and 16 points in the per‐protocol population (ie, median percent decreases of ataxia symptoms of 28% and 31%, respectively). In conclusion, Oral betamethasone could be a promising therapy to relieve ataxia symptoms in A‐T patients; however, long‐term effectiveness and safety must be established. (Current Controlled Trials, number ISRCTN08774933.)

Hemimegalencephaly in Tuberous Sclerosis Complex

The purpose of this case report is to describe the computed tomographic and magnetic resonance imaging findings of the brain of a 16-month-old girl with an uncommon association between hemimegalencephaly and tuberous sclerosis complex. When a large calcification is found within a hemimegalencephalic cerebral hemisphere, further investigation of a suspected associated tuberous sclerosis complex or another phakomatosis is required to determine pertinent treatment options and genetic counseling. (J Child Neurol 2002;17:677-680).

Lamotrigine in typical absence epilepsy

Lamotrigine (LTG) is an anti-epileptic drug effective in partial seizures and generalized epilepsy. There is growing evidence of the usefulness of LTG in childhood (CAE) orjuvenile (JAE) absences resistant to previous treatment. In this study all patients were identified using strict diagnostic criteria and subdivided into two groups. (1) Eight patients affected by absence seizures resistant to valproic acid or ethosuximide, received LTG as an-add-on therapy, (2) seven patients affected by typical absence seizures not previously treated, received LTG monotherapy after the diagnosis. In the patients with resistant absence seizures, a full control of seizures was obtained. In five of them, after a mean period of 12.5 months, the previous anti-epileptic drugs were withdrawn leaving the patients on LTG monotherapy. In one patient, absences relapsed and valproic acid was therefore added again to LTG to regain control of the seizures. In six of the seven patients on LTG monotherapy after the diagnosis, a full control of seizures was obtained. In the seventh patient the drug was stopped due to a skin rash. In conclusion LTG appears to be effective in resistant absence seizures in combination with valproic acid. Moreover, our preliminary data suggest that lamotrigine might be used as monotherapy in typical absence seizures. The advantages and disadvantages of LTG monotherapy in this type of epilepsy are discussed.

Infantile spasms-long term results of ACTH treatment

From a series of 230 subjects with infantile spasms (I.S.) observed from 1955 to 1982, 191 cases with sufficient data on follow-up and evaluation were selected. The period of follow-up in 100 subjects ranged from 3 months to 3 years and was more than 3 years in the remaining 91 patients. Disappearance of spasms and normal psychomotor development was observed in 34 of the 61 idiopathic and post-infectious cases. In 130 subjects with secondary forms normal psychomotor development was observed in only two patients; disappearance of spasms was noted in 54 and normalisation of the EEG in 13 subjects. Satisfactory long term results can be obtained with a relatively low dose of corticotropin in a considerable number of patients having idiopathic and post-infectious forms of I.S. To obtain the best results treatment should be started as soon as possible.

Celiac disease with cerebral calcium and silica deposits: X-ray spectroscopic findings, an autopsy study

An increased incidence of seizures and cerebral calcifications, usually bilateral and located in the occipital cortex, has been reported in celiac patients.The histology of cerebral lesions is not well defined, and their pathogenesis is only speculative. We report the autopsy results of a patient with celiac disease, seizures, and cerebral calcifications who died following a cerebral hemorrhage caused by Fisher-Evans syndrome. Calcifications were restricted to the cortical gray matter and composed of aggregates of small calcified spicules. Calcium deposition was present as psammoma-like bodies, along small vessels, and within neurons. X-ray spectroscopy of the calcified areas revealed that calcium (43%) and silica (57%) were present in the lesions. High silica content was also found in the cerebral hemorrhagic fluid. Silica toxicity has to be considered in regard to the pathogenesis of the cerebral lesions and of the seizures. NEUROLOGY 1996;46: 1088-1092