Rare mtDNA variants in Leber hereditary optic neuropathy families with recurrence of myoclonus

OBJECTIVE

To investigate the mechanisms underlying myoclonus in Leber hereditary optic neuropathy (LHON).

METHODS

Five patients and one unaffected carrier from two Italian families bearing the homoplasmic 11778/ND4 and 3460/ND1 mutations underwent a uniform investigation including neurophysiologic studies, muscle biopsy, serum lactic acid after exercise, and muscle ((31)P) and cerebral ((1)H) magnetic resonance spectroscopy (MRS). Biochemical investigations on fibroblasts and complete mitochondrial DNA (mtDNA) sequences of both families were also performed.

RESULTS

All six individuals had myoclonus. In spite of a normal EEG background and the absence of giant SEPs and C reflex, EEG-EMG back-averaging showed a preceding jerk-locked EEG potential, consistent with a cortical generator of the myoclonus. Specific comorbidities in the 11778/ND4 family included muscular cramps and psychiatric disorders, whereas features common to both families were migraine and cardiologic abnormalities. Signs of mitochondrial proliferation were seen in muscle biopsies and lactic acid elevation was observed in four of six patients. (31)P-MRS was abnormal in five of six patients and (1)H-MRS showed ventricular accumulation of lactic acid in three of six patients. Fibroblast ATP depletion was evident at 48 hours incubation with galactose in LHON/myoclonus patients. Sequence analysis revealed haplogroup T2 (11778/ND4 family) and U4a (3460/ND1 family) mtDNAs. A functional role for the non-synonymous 4136A>G/ND1, 9139G>A/ATPase6, and 15773G>A/cyt b variants was supported by amino acid conservation analysis.

CONCLUSIONS

Myoclonus and other comorbidities characterized our Leber hereditary optic neuropathy (LHON) families. Functional investigations disclosed a bioenergetic impairment in all individuals. Our sequence analysis suggests that the LHON plus phenotype in our cases may relate to the synergic role of mtDNA variants.

Generalised sensory system abnormalities in amyotrophic lateral sclerosis: a European multicentre study

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is defined as a disease of the motor neurones, although several studies indicate involvement of the sensory nervous system.

AIM

To evaluate the sensory nerve conduction studies (NCS) in 88 patients with ALS as part of a European multicentre study.

METHODS

Seven European clinical neurophysiologists examined consecutive series of ALS patients. The examinations were peer reviewed, and the diagnosis of ALS was confirmed clinically.

RESULTS

20 (22.7%) patients with ALS had sensory NCS abnormalities in at least one nerve. Of those, 11 (12.5% of all patients) obtained an additional peer review diagnosis of electrophysiological polyneuropathy. There was no difference between the subgroups of patients with normal versus abnormal sensory NCS findings with respect to age, duration and region of onset.

CONCLUSION

The findings support previous reports of sensory involvement in ALS, and raise the question of whether patients with ALS with sensory nerve abnormalities represent a variant of ALS. ALS associated with generalised sensory system abnormalities may be consistent with degeneration of motor neurones and dorsal root ganglion cells.

Anti-ganglioside antibodies in coeliac disease with neurological disorders

BACKGROUND

Anti-ganglioside antibodies have been described in sera of coeliac patients with peripheral neuropathy and cerebellar ataxia.

AIMS

To investigate the correlation between anti-ganglioside antibodies and neurological involvement in coeliac disease before and after gluten-free diet.

PATIENTS AND METHODS

Twenty-two untreated coeliac patients with neurological dysfunction and 30 untreated coeliacs without neurological dysfunction, 20 patients with neurological disorders, 50 autoimmune disease and 20 blood donors were tested for anti-GM1, anti-GD1b and anti-GQ1b IgG and IgM antibodies by enzyme-linked immunosorbent assay.

RESULTS

IgG antibodies to at least one of the three antigens tested were positive in 64% of coeliac patients with neurological symptoms compared to 30% of coeliacs without neurological dysfunction (P=0.02), 50% of patients with neurological disorders (P=ns), 20% with autoimmune diseases (P=0.003) and none of blood donors (P=0.0001). A strict gluten-free diet determined anti-ganglioside antibody disappearance in about half of coeliacs.

CONCLUSIONS

A significant correlation between anti-ganglioside antibodies and neurological disorders in patients with an underlying coeliac disease has been found. Anti-ganglioside antibodies may represent a new immunological marker to identify neurological impairment in patients with coeliac disease.

Factors associated with climacteric symptoms in women around menopause attending menopause clinics in Italy

OBJECTIVE

To obtain data on correlates of climacteric symptoms in women around menopause attending menopause clinics in Italy.

METHODS

Since 1997 a large cross sectional study has been conducted on the characteristics of women around menopause attending a network of first level menopause outpatient's clinics in Italy. A total of 66,501 (mean age 54.4 years) women are considered in the present paper.

RESULTS

The odds ratios of moderate and severe hot flashes/night sweats were lower in more educated women and (for severe symptoms only) in women reporting regular physical activity. Depression, difficulty to sleep, forgetfulness and irritability tended to be less frequent in more educated women and (depression only) in women reporting regular physical activity. Parous women reported more frequently these symptoms.

CONCLUSIONS

This large study confirms in Southern European population that low education, body mass index and low physical activity are associated with climacteric symptoms. Parous women are at greater risk of psychological symptoms.

Generalised anhidrosis: different lesion sites demonstrated by microneurography and skin biopsy

Generalised anhidrosis (GA) shows a uniform clinical picture whether the pathogenesis involves intrinsic abnormalities of sweat glands or postganglionic sympathetic cholinergic nerve dysfunction. We describe two patients who presented intolerance to heat and anhidrosis. In the first patient, symptoms started at 33 years of age, and were associated with absent tendon reflexes and a mydriatic right pupil unreactive to light. The other patient had been unable to sweat since birth. GA was diagnosed on the basis of clinical findings and thermoregulatory tests. Microneurography and morphological analysis of the skin and its innervation disclosed a different lesion site underlying GA in the two patients, and distinguished between a postganglionic autonomic nerve fibre lesion and sweat gland dysfunction.

POLG mutations causing ophthalmoplegia, sensorimotor polyneuropathy, ataxia, and deafness

The authors identified two novel heterozygous missense transitions in the gene for the mitochondrial polymerase gammaA subunit (POLG) in a family with an autosomal recessive syndrome comprising progressive external ophthalmoplegia (PEO), polyneuropathy, ataxia, sensorineural hearing loss, and affective disorders. These mutations were not detected in 120 healthy control subjects.

Palmaris brevis spasm: an occupational syndrome

Described are five patients who developed palmaris brevis (PB) spasm syndrome following prolonged use of a computer mouse and keyboard. Electromyography showed spontaneous activity characterized by irregular discharges of single motor unit potentials and myokymia from PB muscle that did not disappear after ulnar nerve block at the wrist, suggesting a distal lesion.

Variation in the classification of polyneuropathies among European physicians

OBJECTIVE

Considerable debate still exists regarding the classification of polyneuropathies (PNPs) into predominantly demyelinating, predominantly axonal loss, mixed or unclassified. This study was designed to determine the variation among physicians in the classification of PNPs by using the European Standardized Telematic tool to Evaluate Electromyography knowledge-based systems and Methods (ESTEEM) multicenter database.

METHODS

Seven physicians from 6 laboratories in Europe sent a total of 156 prospectively collected cases of PNP with electromyography (EMG) data including diagnosis (examination diagnosis) to the database. Each physician interpreted the electrophysiological data from all cases (interpretation diagnosis) and a final diagnosis was given at the consensus meetings of the group (consensus diagnosis).

RESULTS

Comparison of each physician's examination diagnosis with his/her interpretation diagnosis, i.e. intra-physician variation, showed a change towards less classified PNPs (P < 0.05). Interpretation diagnoses showed large inter-physician variation in the classification of PNPs. The consensus group was more cautious than individual physicians in classifying PNPs as mixed and axonal. The probability of the consensus diagnosis increased with increasing number of abnormal motor and sensory segments tested.

CONCLUSIONS

Recognition of variation in classification of PNP as shown in this study and suggesting standards of good clinical practice developed by a consensus group may increase the quality of EMG practice.

Familial nocturnal facio-mandibular myoclonus mimicking sleep bruxism

A mother and son presented with a multi-decade history of nocturnal tongue biting and bleeding. In both patients, video polysomnographic recordings documented bursts of electromyographic activity originating in the masseter and spreading to orbicularis oris and oculi muscles, present only during sleep. Faciomandibular myoclonic activity during sleep mimics sleep bruxism and may be familial.

Leber's hereditary optic neuropathy (LHON/11778) with myoclonus: report of two cases

The previously unrecognised association of myoclonus in two patients with LHON with the 11778/ND4 pathogenic mutation is described. EEG failed to disclose epileptic figures, and a back averaging study suggested that myoclonus was cortical in origin in both patients.

Morvan's syndrome: peripheral and central nervous system and cardiac involvement with antibodies to voltage-gated potassium channels

Morvan's 'fibrillary chorea' or Morvan's syndrome is characterized by neuromyotonia (NMT), pain, hyperhydrosis, weight loss, severe insomnia and hallucinations. We describe a man aged 76 years with NMT, dysautonomia, cardiac arrhythmia, lack of slow-wave sleep and abnormal rapid eye movement sleep. He had raised serum antibodies to voltage-gated K(+) channels (VGKC), oligoclonal bands in his CSF, markedly increased serum norepinephrine, increased serum cortisol and reduced levels and absent circadian rhythms of prolactin and melatonin. The neurohormonal findings and many of the clinical features were very similar to those in fatal familial insomnia, a hereditary prion disease that is associated with thalamic degenerative changes. Strikingly, however, all symptoms in our MFC patient improved with plasma exchange. The patient died unexpectedly 11 months later. At autopsy, there was a pulmonary adenocarcinoma, but brain pathology showed only a microinfarct in the hippocampus and no thalamic changes. The NMT and some of the autonomic features are likely to be directly related to the VGKC antibodies acting in the periphery. The central symptoms might also be due to the direct effects of VGKC antibodies, or perhaps of other autoantibodies still to be defined, on the limbic system with secondary effects on neurohormone levels. Alternatively, changes in secretion of neurohormones in the periphery might contribute to the central disturbance. The relationship between VGKC antibodies, neurohormonal levels, autonomic, limbic and sleep disorders requires further study.

Propriospinal myoclonus at the sleep-wake transition: a new type of parasomnia

STUDY OBJECTIVES

To describe the clinical, neurophysiological, and polysomnographic characteristics of propriospinal myoclonus (PSM) at the sleep-wake transition.

DESIGN

Patients referred for insomnia due to myoclonic activity arising during relaxed wakefulness preceding sleep, or complaining of muscular jerks also during intrasleep wakefulness and upon awakening in the morning were considered.

SETTING

All patients underwent EEG-EMG recordings during wakefulness and night sleep. Back-averaging of the EEG activity preceding the jerks was performed. Somatosensory evoked potentials (SEPs), transcranial magnetic stimulation (TMS) and spinal and cranial MRI were also done.

PARTICIPANTS

Four patients were studied all affected with involuntary jerks arising when falling asleep, and one with jerks also during sleep and upon awakening in the morning.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Polysomnographic investigations revealed jerks arising during the sleep-wake transition period. Myoclonic activity was neurophysiologically documented to be of the propriospinal type. SEPs, TMS and MRI were normal

CONCLUSIONS

PSM may have a peculiar relationship with the state of vigilance and represent a sleep-wake transition disorder. In this regard we consider PSM a new type of parasomnia.

Prevalence of primary blepharospasm in a community of Puglia region, Southern Italy

The authors ascertained the prevalence of primary blepharospasm (BSP) in a community located in Puglia, a region in Southern Italy, by focusing on neurologists and ophthalmologists. The crude prevalence rates were 133 per million (95% CI, 61--153) for both focal and segmental BSP, 74 per million (95% CI, 24--173) for focal BSP, and 59 per million (95% CI, 16--151) for segmental BSP. Prevalence rate increased with age. Apraxia of eyelid opening and BSP coexisted in one third of cases.

Familial continuous motor unit activity and epilepsy

A mother and son both had muscle stiffness due to continuous generalized muscle twitching, beginning in childhood and associated with epileptic seizures. Electromyography (EMG) showed continuous motor unit activity (CMUA) at rest, which decreased during ischemia, sleep, and carbamazepine treatment, and was abolished by anesthetic nerve blockade. Genetic analysis disclosed a G724C point mutation in the potassium channel KCNA1 gene. The electrophysiological data suggested pathological impulse generation in both the peripheral and central nervous system, probably related to abnormal ion channel function.

LDL receptor cDNA sequence analysis in familial hypercholesterolemia patients: 5 novel mutations with high prevalence in families originating from southern Italy

We screened a group of patients from southern Italy with clinically diagnosed familial hypercholesterolemia (FH) for mutations of the LDL receptor (LDLR) gene. RNA from each proband was analysed by RT-PCR followed by complete cDNA sequencing. Among 51 unrelated FH families we detected 17 mutations affecting the coding region of the LDLR gene. Five of these mutations, designated R395P, L783fsinsG, IVS15-3C>A, IVS3+5G>A, and 1698-1704delCACCCTAinsGCCCAAT (ITL545MPN), have not yet been reported in the literature. Interestingly, the novel IVS15-3C>A splicing mutation was detected in 20% of our unrelated FH families, suggesting an unusually high prevalence in our local population. Hum Mutat 17:433, 2001.

Equine muscular dystrophy with myotonia

OBJECTIVES

To describe a case of equine muscular dystrophy with myotonia.

METHODS

A 5-year-old horse presented with hypertrophy and delayed relaxation of the muscles of the hindlimbs from age 2 months. Testicular atrophy developed from 2 years of age. Action and percussion myotonia was associated with weakness in these muscles, and EMG showed diffuse myotonic discharges and myopathic features. Biopsy of the gluteal muscle showed adipose and connective tissue infiltration, marked variation in muscle fibre size, and moth-eaten, ring and whorled fibres.

RESULTS

Injection of apamin, a peptide blocker of calcium-activated potassium channels, which inhibits myotonia in human myotonic dystrophy, was ineffective in blocking myotonic discharges. Discharges promptly abated with 2% lidocaine injection.

CONCLUSIONS

Myotonia in this horse is associated with dystrophic changes similar to human myotonic dystrophy, though there are some pharmacological differences.