Absence of linkage to 8q24 in a European family with familial adult myoclonic epilepsy (FAME)

BACKGROUND

Familial adult myoclonic epilepsy (FAME) is defined by autosomal dominant inheritance, adult onset of myoclonus of the extremities, infrequent epileptic seizures, nonprogressive course, abnormality of polyspikes and waves on examination by EEG and photosensitivity, giant somatosensory evoked potentials, enhancement of C reflex, and premyoclonus spike detected by means of the jerk-locked averaging EEG method. These findings were also observed in patients with benign adult familial myoclonic epilepsy (BAFME) and patients with familial cortical tremor. FAME and BAFME have been described only in Japan. The genes responsible for FAME and BAFME were mapped in the same genetic interval in 8q22.3-q24.1

OBJECTIVE

To study clinical and genetic characteristics of a European family with FAME.

METHODS

A four-generation European kindred presenting with FAME, including 18 members, is described. Clinical analysis was performed on 15 living subjects and electrophysiologic study on 5 patients. Linkage analysis was performed with fluorescent microsatellites encompassing the FAME/BAFME locus (8q23.3-q24.1).

RESULTS

Ten living and three deceased relatives had the clinical characteristics of FAME. Mean age at onset of the 10 living patients was 41 years (range, 30-60 years). Eight of the 13 affected subjects had generalized tonic-clonic seizures. Electrophysiologic studies confirmed the diagnosis of FAME in the five patients studied. The pattern of inheritance was consistent with an autosomal dominant inheritance. The locus responsible for FAME/BAFME was excluded.

CONCLUSION

Observation of a European family extends the occurrence of familial adult myoclonic epilepsy to non-Japanese patients. Exclusion of linkage of this family to the locus for familial adult myoclonic epilepsy/benign adult familial myoclonic epilepsy established the genetic heterogeneity of this disorder.

[Meningo encephalitis revealing Q fever: two cases and a review of the literature]

Q fever is a zoonosis caused by Coxiella burnetii. The acute Q fever is usually characterized by a self-limited flu-like syndrome, fever, pneumonia and hepatitis. Symptoms of the chronic Q fever (evolution>3 months) mainly consist of endocarditis with negative culture. Focal neurological symptoms are rarely observed. Neurological symptoms of acute Q fever consist of meningitis or meningo-encephalitis. Neurological symptoms of chronic Q fever are cerebral embolisms from Coxiella burnetii infected heart valves. We herein report two patients with meningoencephalitis revealing acute Q fever.

The prevalence of Sjögren syndrome in patients with primary progressive multiple sclerosis

OBJECTIVE

To assess the prevalence of Sjögren syndrome (SS) in patients with primary progressive MS (PPMS).

BACKGROUND

SS may be considered in the differential diagnosis of MS. Age at onset and clinical presentation are similar in SS and PPMS. However, occurrence of SS in definite cases of PPMS has been recently reported.

METHODS

Proposed clinical and laboratory diagnostic criteria for SS were systematically assessed in 60 consecutive patients with PPMS. The authors questioned all patients about xerophthalmia and xerostomia, biopsied minor salivary glands, and performed a Schirmer test, a salivary gland scintigraphy, and anti-Ro (SSa) and anti-La (SSb) serologies.

RESULTS

Ten patients (16.6%) met four or more criteria for SS. This prevalence is higher than in the general population (1 to 5%) and implies that SS can mimic PPMS.

CONCLUSIONS

The authors propose that SS should be screened for systematically in patients with PPMS.

[Rapidly progressive dementia disclosing primary angiitis of the central nervous system]

Angiitis of the central nervous system involves a wide spectrum of clinical symptoms. Complementary exams (CSF, neuroradiological exams) are not very specific and sensitive. Diagnostic procedures often require cortical and leptomeningeal biopsy. Treatment, based on corticosteroids and cyclophosphamid, have greatly improved prognosis. We report a rapidly progress dementia syndrome that revealed angiitis of the central nervous system. Corticosteroid treatment did not prevent a fatal outcome. Autopsy findings confirmed the diagnosis of central nervous leucocytoclastic angiitis.

High prevalence of CACNA1A truncations and broader clinical spectrum in episodic ataxia type 2

OBJECTIVE

To characterize the nature of CACNA1A mutations in episodic ataxia type 2 (EA2), to search for mutations in sporadic cases, and to delineate better the clinical spectrum.

BACKGROUND

EA2 is an autosomal dominant disorder characterized by recurrent acetazolamide-responsive attacks of cerebellar ataxia. The mutated gene, CACNA1A, located on chromosome 19, encodes the alpha1A subunit of a voltage-dependent calcium channel. So far, only three CACNA1A mutations have been identified-in two EA2 families and in one sporadic case. These three mutations disrupted the reading frame and led to truncated proteins. Interestingly, distinct types of CACNA1A mutations have been identified in familial hemiplegic migraine (missense mutations) and spinocerebellar ataxia type 6 (SCA-6) progressive cerebellar ataxia (expanded CAG repeats). However, except for SCA-6, these genotype-phenotype correlations relied on the analysis of very few families.

METHODS

To characterize CACNA1A mutations, eight familial and seven sporadic EA2 patients were selected. All 47 exons of CACNA1A were screened by a combination of single-strand conformer polymorphism and sequencing analysis. In addition, the length of the CAG repeat has been determined in all patients.

RESULTS

Seven new mutations were detected in four multiple case families and three sporadic cases. Six of them lead most likely to truncated or aberrant proteins. CAG repeat sizes were in the normal range.

CONCLUSION

These data clearly establish the specificity of EA2 mutations compared with SCA-6 and familial hemiplegic migraine. Detailed clinical analysis of the mutation carriers showed the highly variable penetrance and expression of this disorder: Several of the carriers did not show any clinical symptom; others displayed atypical or permanent neurologic symptoms (such as recurrent, transient diplopia or severe, permanent, and isolated cerebellar ataxia).

[Friedreich's ataxia and hereditary vitamin E deficiency. Case study]

A 24-year-old patient, born from consanguineous parents, consulted for cerebellar syndrome, ataxia, loss of proprioception, bilateral Babinski sign and lower limbs areflexia. No mutation on Friedreich's ataxia gene was found. Plasmatic vitamin E level was extremely low. Point mutation on gene coding for alpha-tocopherol transfer protein (alpha-TTP) confirmed the diagnosis of familial isolated vitamin E deficiency (AVED). Vitamin E therapy restored normal serum levels and neurological symptoms were stabilized.

Poor sleep in adolescents: a study of 869 17-year-old Italian secondary school students

Subjective sleep quality and its related factors were investigated in 869 (530 F, 339 M) 17-year-old adolescents, who were selected from the pupils of state-run secondary schools in the city of Pavia in the north west of Italy. The study was conducted cross sectionally, and it consisted of a questionnaire based survey. One hundred and forty-two subjects (16.5% of the whole sample, 19% of the females and 11.7% of the males) met the criteria chosen for definition as poor sleepers (namely, a complaint of 'non restorative nocturnal sleep', 'often' or 'always' over the previous 12 mo). A significant association was found between chronic poor sleep and (1) gender (female) (2) emotional factors, such as worries, anxiety and depression (3) poor sleep hygiene (4) arousal related parasomnia. Only 4% of poor sleepers took sleep promoting drugs (including benzodiazepines, homeopathic products and other medications), generally without seeking medical advice.

Breathing during sleep in myasthenia gravis

The aim of this study was to assess breathing patterns during sleep in patients with generalized mild myasthenia gravis. Fourteen patients (13 F; 1M, age range 20-40 years) in a stable clinical and functional state underwent a sleep questionnaire, baseline respiratory function tests and standard nocturnal polysomnography. All of the patients had normal daytime blood-gas values, except one who showed mild hypoxemia. No patient complained of disturbed sleep; six patients reported snoring. In five patients nocturnal polysomnography showed the occurrence of short and infrequent central apneas mainly during REM sleep, together with a drop in HbSaO2 levels of more than 5% of the baseline wakefulness value. Our data indicate that, in patients with mild generalized MG in a stable functional state, breathing pattern instability during sleep is infrequent and, when it occurs, is mild and mainly related to REM sleep.

Eye movement quantitative evaluation before and after high-dose 6-methylprednisolone in multiple sclerosis

We studied saccadic and smooth pursuit eye movements in 24 patients suffering from multiple sclerosis during disease worsening, before and after high-dose 6-methylprednisolone infusions. Quantitative evaluation of saccades was based on amplitude/duration and amplitude/peak velocity relationships, precision (i.e. the ratio of actual to desired saccade amplitude) and the latency, whereas smooth pursuit eye movements were studied using target velocity/performance index relationship. At basal recordings, 22/24 (91.7%) of the patients showed at lest one abnormality. Eleven of the 24 patients (45.8%) showed modification of one or several parameters: improvement in 6 patients, worsening in 2, coexistence of both trends in 3. Latency improvement was the only significant modification when patients were considered as a group. Neurophysiological modifications did not correspond to clinical changes.

A clinically oriented approach to smooth pursuit eye movement quantitative evaluation

The electrooculographic technique was used to record smooth pursuit eye movements in 71 healthy subjects homogeneously distributed within an age range between the 2nd and the 6th decades. The target moved at constant velocity (triangular ramps) and 9 different target velocities (V), from 10 deg/s to 50 deg/s were considered and presented according to pseudorandom sequence. Ad hoc software suppressed catch-up saccades so that a pursuit index (PI) value was computed for each ramp taking into account only the smooth pursuit tracking modality. It was demonstrated that the relationship between V and PI could be described by the linear model PI = a + b * V. Pursuit index was proved to be influenced by the age of subject (decade factor in the analysis of variance), since an almost linear increase in b values yields a reduction of pursuit index values. The method was tested in 22 multiple sclerosis patients and an association was found between the occurrence of cerebellar signs and the reduction of a value.

Quantitative evaluation of saccadic and smooth pursuit eye movements. Is it reliable?

PURPOSE

The authors evaluated the reliability of the coefficients of the (1) amplitude/duration and (2) amplitude/peak velocity relationships of the mean precision values and the mean latency values (saccadic eye movements) and the coefficients of the target velocity/gain relationship (smooth pursuit eye movements). They computed test-retest maximum variability limits for these parameters.

METHODS

After a 1-week interval, saccadic and smooth pursuit eye movements were recorded twice from 20 healthy subjects; 12 of these subjects underwent a third recording session. The estimate of the intraclass coefficient of reliability, R, was adopted to evaluate the reliability of eye movement quantitative analysis.

RESULTS

The data demonstrated that the reliability was fairly good for the amplitude/peak velocity relationship, was good for the precision, and was excellent for the amplitude/duration, the target velocity/gain relationships, and the latency.

CONCLUSIONS

Quantitative analysis of both saccadic and smooth pursuit eye movements is reliable. One statistic used to estimate reliability, ie, the within-subjects mean square value, also enables the determination of test-retest normal variability values for both the variances and the differences of measurements.

The reliability of eye movement quantitative evaluation. II. Smooth pursuit eye movements

We adopted the estimate of the intraclass coefficient of reliability, R, to evaluate the reliability of smooth pursuit eye movement quantitative analysis. At a one-week interval, we recorded twice smooth pursuit eye movements from fifteen healthy subjects by means of the binocular electrooculographic technique. R was computed for the constant and the slope of the target velocity/gain relationships. R values were rated good for the slope and excellent for the constant. Finally, we computed for each parameter the maximum variability value according to two differing methods; on the basis of the within-subjects mean square values, we defined the normal range of biological test-retest variability for the two parameters.

The reliability of eye movement quantitative evaluation. I. Saccadic eye movements

We adopted the estimate of the intraclass coefficient of reliability, R, to evaluate the reliability of saccadic eye movements quantitative analysis. At a one-week interval we recorded refixative saccadic eye movements twice from fifteen healthy subjects by means of the binocular electrooculographic technique. R was computed for the constants and the slopes of the amplitude/duration and the amplitude/peak velocity relationships, for the mean precision values and for the mean latency values adjusted for subject's age. Our data demonstrated that the reliability of saccade parameters is fairly good for the amplitude/peak velocity relationship, good for the precision and very good for the amplitude/duration relationship. Finally, we believe that the normal variability values we obtained can be usefully employed in neurophysiological longitudinal studies not only in normal subjects, but also in pathological condition provided the more reliable parameters and the more adequate strategies to compute normal variability values are chosen.