Heterozygous CLCN1 mutations can modulate phenotype in sodium channel myotonia.

Nondystrophic myotonias are characterized by muscle stiffness triggered by voluntary movement. They are caused by mutations in either the CLCN1 gene in myotonia congenita or in the SCN4A gene in paramyotonia congenita and sodium channel myotonias. Clinical and electrophysiological phenotypes of these disorders have been well described. No concomitant mutations in both genes have been reported yet. We report five patients from three families showing myotonia with both chloride and sodium channel mutations. Their clinical and electrophysiological phenotypes did not fit with the phenotype known to be associated with the mutation initially found in SCN4A gene, which led us to screen and find an additional mutation in CLCN1 gene. Our electrophysiological and clinical observations suggest that heterozygous CLCN1 mutations can modify the clinical and electrophysiological expression of SCN4A mutation.

Prognostic value of EEG in very premature newborns.

OBJECTIVE: To evaluate the prognostic value of EEG regarding the psychomotor outcomes of very premature newborns. METHODS: 76 premature infants <30 weeks gestation were enrolled between January 2001 and August 2004. They were examined at 4 and 9 months corrected ages, and at 18 months, 3-4 years and 5-6 years. EEGs performed in the neonatal period were analysed by two neurologists blind to the child's outcome. RESULTS: The mean follow-up was 5.6 years. 25 infants had normal neurological development and all EEGs were normal for 22 of these. 36 others had developmental disabilities (7 motor sequelae and 29 delayed psychomotor development). Of 187 EEGs, 43 were dysmature, 13 disorganised, 2 displayed electrical seizures without clinical manifestations and 15 showed other abnormal features. Dysmaturity was the predominant EEG pattern in newborns with severe or moderate sequelae and was persistent on several EEGs in 12 of these. In contrast, only three infants with normal development had a dysmature pattern on one EEG. All infants with a disorganised pattern had cognitive sequelae, and two had cerebral palsy. The sensitivity of EEG regarding psychomotor outcome was 83.3%, the specificity was 88% and the positive predictive value was 90.9%. CONCLUSIONS: Very preterm neonates remain at high risk of neurological sequelae and EEG is a sensitive method for assessing neuromotor and cognitive prognosis. A dysmature pattern was the predominant EEG characteristic in infants who developed severe or moderate impairment. Early postnatal tracing is useful but additional recordings are generally necessary to detect high-risk newborns.

Late-onset cervicoscapular muscle atrophy and weakness after radiotherapy for Hodgkin disease: a case series.

Patients with cervical or mediastinal Hodgkin disease (HD) classically underwent chemotherapy plus extended-field radiation therapy. We report six patients who gradually developed severe atrophy and weakness of cervical paraspinal and shoulder girdle muscles 5-30 years after mantle irradiation for HD. Although clinical presentation was uniform, including a dropped head syndrome, electrophysiological and pathological findings were rather heterogeneous. Either neurogenic or myogenic processes may be involved and sometimes combined. We discuss the pathophysiological mechanisms underlying these cervicoscapular motor complications of mantle irradiation in HD.

[Severe Guillain-Barré syndrome and pregnancy: two cases with rapid improvement post-partum]. / Syndrome de Guillain-Barré sévère et grossesse: deux cas d'amélioration rapide en post-partum.

INTRODUCTION: Guillain-Barré syndrome can occur at any time of pregnancy with the same incidence as in the general population. Observations. We report two cases of patients who developed a progressive ascending paralysis during the second trimester of pregnancy. The worsening of the respiratory insufficiency for one of them required a transfer to an intensive care unit for artificial ventilation lasting 102 days. In the two cases, cerebrospinal fluid examination revealed albumin-cytological dissociation and repeated electrophysiological studies showed typical features of demyelinating neuropathy with conduction blocks. Biological investigations, especially CMV and Campylobacter jejuni serologies, were all negative. Intravenous immunoglobulin infusions, in one case associated with high doses of corticosteroïds, were ineffective. Rapid improvement was observed in the two patients after delivery. CONCLUSION: These cases raise the question of the relationships between the Guillain-Barré syndrome and pregnancy. The occurrence of the disease, as well as the rapid recovery in post-partum, could be consecutive to a partial failure of the maternal immunological tolerance toward the fetus.

[Indications of electroencephalogram in the newborn]. / Indications de l'électroencéphalogramme en période néonatale. Recommandations du groupe de neurophysiologie clinique de l'enfant.

The electroencephalogram (EEG), an easy-to-use and non invasive cerebral investigation, is a useful tool for diagnosis and early prognosis in newborn babies. In newborn full term babies manifesting abnormal clinical signs, EEG can point focal lesions or specific aetiology. EEG background activity and sleep organization have a high prognostic value. Tracings recorded over long period can detect seizures, with or without clinical manifestations, and differentiate them from paroxysmal non epileptic movements. The EEG should therefore be recorded at the beginning of the first symptoms, and if possible before any seizure treatment. When used as a neonatal prognostic tool, EEG background activity is classified as normal, abnormal (type A and type B discontinuous and hyperactive rapid tracing) or highly abnormal (inactive, paroxysmal, low voltage plus theta tracing). In such cases, the initial recording must be made between 12 and 48 h after birth, and then between 4 and 8 days of life. Severe EEG abnormalities before 12 h of life have no reliable prognostic value but may help in the choice of early neuroprotective treatment of acute cerebral hypoxia-ischemia. During presumed hypoxic-ischemic encephalopathy, unusual EEG patterns may indicate another diagnosis. In premature newborn babies (29-32 w GA) with neurological abnormalities, EEG use is the same as in term newborns. Without any neurological abnormal sign, EEG requirements depend on GA and the mother's or child's risk factors. Before 28 w GA, when looking for positive rolandic sharp waves (PRSW), EEG records are to be acquired systematically at D2-D3, D7-D8, 31-32 and 36 w GA. It is well known that numerous and persistent PRSW are related to periventricular leukomalacia (PVL) and indicate a bad prognosis. In babies born after 32 GA with clinically severe symptoms, an EEG should be performed before D7. Background activity, organization and maturation of the tracing are valuable diagnosis and prognosis indicators. These recommendations are designed (1) to get a maximum of precise informations from a limited number of tracings and (2) to standardize practices and thus facilitate comparisons and multicenter studies.

[Polyradiculoneuropathy in an adult with primitive hyperoxaluria]. / Polyradiculoneuropathie au cours d'une hyperoxalurie primitive de l'adulte.

From the age of 31 a patient began to suffer from recurrent calcium oxalate urolithiasis. Liver biopsy showed a decrease in catalytic activity of the hepatic peroxisomal enzyme alanine: glyoxilate aminotransferase (AGT), which was mistargeted from peroxisomes to mitochondria. The genetic analysis revealed a mutation of the AGT gene. At age 47 he developed end-stage renal failure and underwent hemodialysis. After 12 months of hemodialysis he presented a rapidly declining clinical condition, a decrease of the residual renal function, a livedo reticularis with painful of extremities, and shortly thereafter a general weakness, which predominated on lower limbs. Apart from renal failure, routine biological examination and CSF were normal. Nerve conduction studies and electromyography supported the diagnosis of polyradiculoneuropathy. Pathological studies revealed mixed demyelinating-axonal lesions and deposits of calcium oxalate crystals within the media and the intima of epineural arterioles. A combined liver-kidney transplant was rapidly performed. The patient's condition improved in a few months and motor signs completely disappeared.

Differential diagnosis of a vascular leukoencephalopathy within a CADASIL family: use of skin biopsy electron microscopy study and direct genotypic screening.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a condition caused by mutations of Notch3 gene on chromosome 19. Ultrastructural analysis of skin vessels discloses typical granular osmiophilic material (GOM) within the vascular smooth muscle basal lamina. We describe a CADASIL family in which two members suffering from a vascular leukoencephalopathy were shown to be CADASIL phenocopies: clinical and magnetic resonance imaging (MRI) findings in these two patients were similar to those observed in their affected relatives. However, the skin biopsy performed on one of them did not reveal any GOM in the vascular smooth muscle cells, and the Notch3 mutation present in this family was shown to be absent in these two individuals. We emphasize the role of a direct DNA test for gene mutation to make a differential diagnosis between CADASIL and other forms of vascular leukoencephalopathy.

Psychoacoustical deficits related to bilateral subcortical hemorrhages. A case with apperceptive auditory agnosia.

We report a case of acute deafness secondary to bilateral hemorrhages involving the external capsule and extending to both temporal isthmi. The lesions probably disrupted both auditory radiations. Deafness disappeared within 2 weeks leading to a transient auditory agnosia for environmental and verbal sounds. Performance on audiological and neurolinguistic tests were consistent with the hypothesis of a deficit of non-specific auditory processes. Psychoacoustical deficits related to subcortical lesions are very rare and might differ from those due to cortical lesions by the lack of aphasia. The present case and both previous cases with subcortical lesions might suffer from auditory agnosia of apperceptive type. Its characteristics and the role of non-specific auditory processes are discussed using the data obtained from this third case.

Effects of chronic electrostimulation on rat soleus skinned fibers during hindlimb suspension.

In order to counteract the changes of the contractile properties of the rat soleus occurring during 10 days of hypokinesia-hypodynamia, due to hindlimb suspension (HS), two different patterns of electrostimulation were applied to the tibial nerve. The contractile properties of single chemically skinned muscle fibers were investigated using the tension-pCa relationship characteristics, the similar or different calcium and strontium affinities, and by measuring the P/tmax kinetic parameters. Our results showed that a pattern similar to firing rates of motoneurons innervating slow twitch muscles inhibited the slow to fast fiber changes observed during HS, whereas a pattern similar to firing rates of motoneurons from fast twitch muscles seemed to favor these changes. Since neither pattern maintained the isometric contractile force developed by the soleus fibers, we concluded that the decrease in mechanical strains imposed on the muscle during unloading was the main factor for the development of atrophy, while the kinetic changes might be predominantly modulated by the nervous command.

Motor evoked potentials to magnetic stimulation: technical considerations and normative data from 50 subjects.

Magnetic stimulation of the brain and cervical and lumbar spinal roots was performed on 50 healthy volunteers. Compound muscle action potentials (CMAPs) were recorded from biceps brachii, abductor digiti minimi (ADM), rectus femoris and tibialis anterior (TA). We assessed central conduction times by subtraction of peripheral from central latencies and compared results using either spinal root stimulation or the F-wave method. Side-to-side differences of total conduction time, peripheral conduction time and central conduction time (CCT) were measured and the effect of clockwise vs counterclockwise stimulations on latencies and sizes of CMAPs is emphasized. Amplitudes and areas of CMAPs were expressed as a percentage of the peripheral M response for ADM and TA. There was a positive correlation between CCT to the lumbosacral region and height, but not between the cervical region and height. No correlation was observed between genders and central conduction times, amplitudes or areas of CMAPs.

[Mixed pre- and postsynaptic neuromuscular block]. / Bloc neuromusculaire mixte pré- et post-synaptique.

We report a new case of neuromuscular block overlap between Myasthenia Gravis and Eaton-Lambert syndrome. A 64-year-old man with a 4-months history of gait disturbance was admitted for ophthalmoplegia worsening during exercise and decreasing at rest. Clinical examination after exercise, revealed limbs weakness and areflexia, palsy of the left eye abduction and a left ptosis. The level of anti-acetylcholin-receptor antibodies was high. Electrophysiological explorations revealed a decrement at 3 Hz and a increment at 30 Hz, with a reduction in amplitude of the initial motor potential. This patient improved under a combination of guanidine and anticholinesterase drugs. From this case and 9 previously reported cases, we propose 4 criteria for the diagnosis of such neuromuscular blocks: 1) exercising symptoms and signs, including areflexia, 2) presence of anti-acetylcholin-receptor antibodies, 3) reduction of the amplitude of the initial motor potential, with a decrement at 3 Hz, and an increment at 30 Hz, and 4) clinical and electrophysiological improvement under guanidine and anticholinesterasic drugs therapy.

Early hypopituitarism following cavernous sinus thrombosis: total recovery within 1 year.

Hypopituitarism related to cavernous sinus thrombosis is a very rare event which usually occurs at least 1 year after the acute stage. We report a case which distinguished itself from the previously reported cases through (i) its occurrence during the acute stage and (ii) its total recovery within 1 year. Early anterior hypopituitarism is probably more frequent than expected on the basis of reported cases and it may contribute to the high rate of mortality in cavernous sinus thrombosis. This underscores the need to consider hypopituitarism in every patient with cavernous sinus thrombosis.

[Prolonged remission in subacute sclerosing panencephalitis: 2 cases]. / Rémissions prolongées dans la panencéphalite sclérosante subaigue: 2 cas.

Long survival in subacute sclerosing panencephalitis (SSPE), including total disappearance of clinical signs, is rare. Two cases are reported. They concern a girl and a boy who, at age 13 and 15, developed SSPE and are still in remission 6 and 5 years later. After a typical onset and course over periods of 12 and 18 months, clinical improvement was observed and periodic EEG complexes disappeared. However, the electrophoretic oligoclonal pattern of CSF proteins and the elevated measles titers persisted (in one case specific CSF IgM were still increased 6 years after the onset). MRI showed asymmetrical areas of high-intensity signal in both white and gray matter, predominant in the temporal, parietal and occipital regions. The age at which SSPE begins and the interval between measles and SSPE onset are not prognostic factors. On the other hand, in reported cases with lasting remission SSPE did not progress beyond Jabbour's stage II. The second typical feature of these long-term improvements is disappearance of EEG periodic complexes and emergence of a normal basic background activity. No other prognostic factor has been reported.