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ABSTRACT: OBJECTIVE: To evaluate the relationship between sensory hyperexcitability as revealed by giant SEPs and the SEP recovery function (SEP-R) in a series of patient with progressive myoclonic epilepsy of Unverricht-Lundborg type, identified as epilepsy, progressive myoclonic 1A (EPM1A), MIM #254800. METHODS: We evaluated SEPs by applying median nerve stimuli and SEP-R using paired stimuli at inter-stimulus intervals (ISIs) of between 20 and 600ms in 25 patients and 20 controls. The SEPs were considered "giant" if the N20P25 and P25N33 amplitudes exceeded normal mean values by +3SD. RESULTS: During the paired-stimulus protocol, the SEPs elicited by the second stimulus (S2) were detectable at all ISIs but consistently suppressed in the 13 patients with giant SEPs reflecting a significantly delayed SEP-R. Maximal suppression roughly corresponded to the plateau of a broad middle latency (>100ms) wave pertaining to the S1 response. CONCLUSIONS: The cortical processing dysfunction generating giant SEPs in EPM1A patients consistently combines with a long-lasting suppression of hyperexcitability that leads to a delayed giant SEP-R without obstructing the response to incoming stimuli. SIGNIFICANCE: The delayed SEP-R is not due to true inhibition but the suppression of aberrant hyper-synchronisation sustaining giant SEPs. A broad middle latency SEP component adds a significantly suppressive effect. This suggests that cortico-subcortical circuitries contribute to both the gigantism and the delayed SEP-R.
Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 12/2012; · 3.12 Impact Factor
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C Marchesi,
M Milani,
M Morbin,
M Cesani,
G Lauria, V Scaioli,
G Piccolo,
G M Fabrizi,
T Cavallaro,
F Taroni,
D Pareyson
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ABSTRACT: To report 4 cases of autosomal recessive hereditary neuropathy associated with novel mutations in the periaxin gene (PRX) with a review of the literature. Periaxin protein is required for the maintenance of peripheral nerve myelin. Patients with PRX mutations have early-onset autosomal recessive demyelinating Charcot-Marie-Tooth disease (CMT4F) or Déjèrine-Sottas neuropathy (DSN). Only 12 different mutations have been described thus far.
Case reports and literature review.
Four patients from 3 unrelated families (2 siblings and 2 unrelated patients) were affected by an early-onset, slowly progressive demyelinating neuropathy with relevant sensory involvement. All carried novel frameshift or nonsense mutations in the PRX gene. The 2 siblings were compound heterozygotes for 2 PRX null mutations (p.Q547X and p.K808SfsX2), the third patient harbored a homozygous nonsense mutation (p.E682X), and the last patient had a homozygous 2-nt insertion predicting a premature protein truncation (p.S259PfsX55). Electrophysiologic analysis showed a severe slowing of motor nerve conduction velocities (MNCVs, between 3 and 15.3 m/s) with undetectable sensory nerve action potentials (SNAPs). Sural nerve biopsy, performed in 2 patients, demonstrated a severe demyelinating neuropathy and onion bulb formations. Interestingly, we observed some variability of disease severity within the same family.
These cases and review of the literature indicate that PRX-related neuropathies have early onset but overall slow progression. Typical features are prominent sensory involvement, often with sensory ataxia; a moderate-to-dramatic reduction of MNCVs and almost invariable absence of SNAPs; and pathologic demyelination with classic onion bulbs, and less commonly myelin folding and basal lamina onion bulbs.
Neurology 11/2010; 75(20):1830-8. · 8.31 Impact Factor
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ABSTRACT: Previous studies have demonstrated that the event-related potential (ERP) evoked by a note shows substantial differences depending on whether the note is part of a melodic context or presented in an unstructured repetition. In particular, the N2 component has been found to have considerably increased latency and a more frontal topography for notes presented in a melody. An open question is whether such effect is related to the 'meaningfulness' of a note sequence, that is due to the formation of abstract melodic entities, rather than more simply an indicator of cognitive load associated with processing a structurally-complex sequence as opposed to an unstructured repetition. In this study, we addressed this issue by recording ERPs from 10 healthy non-musicians listening to eight one-part unfamiliar tonal melodies and eight sequences of random notes. The two stimuli were matched for distribution of pitch, intervals and note duration as well as for entropy of the time-series of pitch and duration. While tonal melodies were rated more meaningful (p<0.001) and pleasant (p<0.001) by all participants, no effects were found for the N2 component amplitude (p> or =0.8) and latency (p=0.2). Combined with previous findings, this indicates that the N2 evoked by each individual note responds to the structural complexity of the note sequence, i.e., to the presence of pitch and duration changes, but not to higher-level processing related to the formation of abstract melodic entities. In contrast, we found that the amplitude of the P2 component was marginally (p=0.04) elevated for random notes as compared to tonal melodies. This may be related to attentional modulation, or more specifically to associative components of auditory processing.
Brain research bulletin 08/2010; 83(1-2):23-8. · 2.18 Impact Factor
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A Pace,
D Giannarelli,
E Galiè,
A Savarese,
S Carpano,
M Della Giulia,
A Pozzi,
A Silvani,
P Gaviani, V Scaioli,
B Jandolo,
L Bove,
F Cognetti
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ABSTRACT: The clinical use of cisplatin chemotherapy is limited by severe peripheral neurotoxicity reported in up to 90% of patients receiving a cumulative dose higher than 300 mg/m(2). The present study evaluates the neuroprotective effect of antioxidant supplementation (vitamin E) in patients treated with cisplatin chemotherapy.
A total of 108 patients treated with cisplatin chemotherapy were randomly assigned to receive vitamin E supplementation (alpha-tocopherol 400 mg/day) or placebo. Treatment was started orally before chemotherapy and continued for 3 months after the suspension of cisplatin.
Of 108 randomized patients, 68 received at least one clinical and neurophysiologic examination after cisplatin CT; 41 patients received a cumulative dose of cisplatin higher than 300 mg/m(2) and were eligible for statistical analysis: 17 in the vitamin E group (group 1) and 24 in the placebo group (group 2). The incidence of neurotoxicity was significantly lower in group 1 (5.9%) than in group 2 (41.7%) (p < 0.01). The severity of neurotoxicity, measured with a validated neurotoxicity score (Total Neuropathy Score [TNS]), was significantly lower in patients receiving vitamin E than those receiving placebo (mean TNS 1.4 vs 4.1; p < 0.01).
This phase III study confirms the neuroprotective role of vitamin E against cisplatin peripheral neurotoxicity. Vitamin E supplementation should be adopted in patients receiving cisplatin-based chemotherapy. Classification of evidence: This study provides Class II evidence that vitamin E supplementation significantly reduces the relative risk of developing signs or symptoms of neurotoxicity (relative risk = 0.14) (95% confidence interval = 0.02-1.00, p < 0.05).
Neurology 03/2010; 74(9):762-6. · 8.31 Impact Factor
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ABSTRACT: We studied changes in event-related desynchronization/synchronization (ERD/ERS) patterns in patients with Unverricht-Lundborg disease (ULD), presenting with prominent action myoclonus. We analyzed the movement-related ERD/ERS in alpha and beta frequency bands in 15 patients using self-paced finger extension as a motor paradigm and we compared the results with those obtained in 12 healthy volunteers. In all ULD patients, alpha- and beta-ERD regularly occurred with onset and location similar to that found in healthy controls, but the desynchronization of alpha activity was significantly greater than in controls (C3: -64.4+/-9.8% vs. -49.7+/-14.8%; p=0.004). Moreover, in the patients, both alpha- and beta-ERD spread toward frontal electrodes. In controls, the post-movement beta-ERS regularly occurred; it was absent in eight patients with severe action myoclonus, while, in seven patients with mild or moderate myoclonus, the beta-peak was significantly smaller with respect to that measured in controls (55.6+/-15.1% vs. 153.9+/-99.8%, p=0.006). The failure of beta-ERS well-correlated with motor impairment resulting from action myoclonus, whereas SSEPs and long-loop reflexes performed to detect signs of cortical hyperexcitability showed inconsistent changes. In ULD patients, ERD/ERS changes indicate an increased activation of motor cortex during movement planning and a great reduction of post-excitatory inhibition of motor cortex. The changes involving beta-ERS had a significant relationship with the functional disability in individual patients and might play a pathogenic role in the motor dysfunction.
NeuroImage 11/2006; 33(1):161-8. · 5.89 Impact Factor
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K Coen,
D Pareyson,
M Auer-Grumbach,
G Buyse,
N Goemans,
K G Claeys,
N Verpoorten,
M Laurà, V Scaioli,
W Salmhofer,
T R Pieber,
E Nelis,
P De Jonghe,
V Timmerman
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ABSTRACT: Hereditary sensory and autonomic neuropathy type II (HSAN-II) is caused by recessive mutations in the HSN2 gene assigned to chromosome 12p13.33. The authors report three unrelated HSAN-II families with homozygous or compound heterozygous mutations resulting in the truncation of the HSN2 protein. Genotype-phenotype correlations indicated that HSN2 mutations are associated with an early childhood onset of a predominantly sensory neuropathy, complicated by acromutilations in both upper and lower limbs.
Neurology 04/2006; 66(5):748-51. · 8.31 Impact Factor
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ABSTRACT: As paclitaxel may induce positive spontaneous visual symptoms or persistent visual loss, we carried out this electrophysiological study in an attempt to clarify the underlying pathophysiological mechanisms of visual pathway involvement. The study involved 30 breast cancer patients: 14 were treated with paclitaxel alone (group A) and 16 with paclitaxel and adriamycin (group B). Pattern visual evoked potentials (VEPs), and transient, 30 Hz flicker (FLK) and oscillatory potential (OP) white flash electroretinograms (ERGs), were recorded before treatment, after the third and sixth therapeutic cycle, and at the end of the programmed regimen. Pretreatment: Abnormal VEP and OP and FLK changes occurred more than 75% of patients; transient ERGs were normal in more than 90%. Serial recordings: VEPs remained unchanged in both goups. In group A, ERG b-wave latency significantly increased (ANOVA P<0.005), and OP and FLK were characterised by non-significant mild attenuation. Several combinations of ERG, OP, FLK and VEP changes occurred in 50% of the patients. The association between transitory lightining scotoma or blurred vision (reported by 12 patients) and VEP, ERG and FLK was poor, whereas that with OP was satisfactory. A few patients showed stable and persistent subclinical electrophysiological changes. Electrophysiological changes during treatment revealed the involvement of both the retina and anterior optic pathway. There was only a weak correlation between visual symptoms and electrophysiology. We suggest that the most likely mechanism of visual symptoms and electrophysiological changes during paclitaxel administration is vascular dysregulation in the retina, or ischemic mechanisms when the optic nerve is involved.
Journal of Neuro-Oncology 03/2006; 77(1):79-87. · 3.21 Impact Factor
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ABSTRACT: Charcot-Marie-Tooth disease (CMT) is a genetically heterogeneous group of disorders sharing the same clinical phenotype, characterized by distal limb muscle wasting and weakness, usually with skeletal deformities, distal sensory loss, and abnormalities of deep tendon reflexes. Mutations of genes involved in different functions eventually lead to a length-dependent axonal degeneration, which is the likely basis of the distal predominance of the CMT phenotype. Nerve conduction studies are important for classification, diagnosis, and understanding of pathophysiology. The subdivision into demyelinating CMT1 and axonal CMT2 types was a milestone and is still valid for the majority of patients. However, exceptions to this partition are increasing. Intermediate conduction velocities are often found in males with X-linked CMT (CMTX), and different intermediate CMT types have been identified. Moreover, for some genes, different mutations may result either in demyelinating CMT with slow conduction, or in axonal CMT. Nerve conduction slowing is uniform and diffuse in the most common CMT1A associated with the 17p12 duplication, whereas it is often asymmetric and nonhomogeneous in CMTX, sometimes rendering difficult the differential diagnosis with acquired inflammatory neuropathies. The demyelinating recessive forms, termed CMT4, usually have early onset and run a more severe course than the dominant types. Pure motor CMT types are now classified as distal hereditary motor neuronopathy. The diagnostic approach to the identification of the CMT subtype is complex and cannot be based on the clinical phenotype alone, as different forms are often clinically indistinguishable. However, there are features that may be of help in addressing molecular investigation in a single patient. Late onset, prominent or peculiar sensory manifestations, autonomic nervous system dysfunction, cranial nerve involvement, upper limb predominance, subclinical central nervous system abnormalities, severe scoliosis, early-onset glaucoma, neutropenia are findings helpful for diagnosis.
NeuroMolecular Medicine 02/2006; 8(1-2):3-22. · 5.00 Impact Factor
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E Visani,
P Agazzi, V Scaioli,
G Giaccone,
S Binelli,
L Canafoglia,
F Panzica,
F Tagliavini,
O Bugiani,
G Avanzini,
S Franceschetti
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ABSTRACT: To characterise flash visual evoked potentials (FVEPs) in 20 patients with Creutzfeldt-Jacob disease (CJD), and assess the relationships between spontaneous EEG patterns and the responses to individual stimuli.
We analysed the shape and time course of periodic sharp wave complexes (PSWCs) and responses to 1 Hz flashes. In nine patients, we applied an algorithm based on an autoregressive model with exogenous input (ARX) to estimate responses to individual random flashes and their interaction with PSWCs.
The FVEPs included P1 and N1 components in all patients, and the P2 peak in 18. Eight patients showed giant FVEPs (N1-P2>60 V), all of whom had an MM polymorphism in codon 129 of the prion protein gene; in seven cases, the presence of giant FVEPs correlated with a prominent and almost continuous periodic EEG pattern. Giant N1-P2 abnormally spread on the anterior scalp regions, and had a different waveform distribution from that of the PSWCs. In five patients with a normal or slightly enlarged average N1-P2 amplitude, single sweep (ARX) analysis revealed a period of relative refractoriness following individual PSWCs. In four patients with 'giant' FVEPs, the individual responses occurred regardless of the interval between the stimulus and previous PSWC, but their amplitude had an inverse relationship with the interval length.
Giant responses to flash stimuli are a common finding in CJD patients (40% of our cases). Single sweep ARX analysis showed that PSWCs were followed by a period of partial refractoriness, which prevented most of the individual responses to flashes, but not giant FVEPs. The association between prominent spontaneous paroxysms and giant FVEPs suggests that both are due to a common hyperexcitable change favouring neuronal synchronisation.
Our data contribute to clarifying the debated problem of the occurrence of giant FVEPs in CJD and their relationships with the spontaneous periodic EEG pattern.
Clinical Neurophysiology 04/2005; 116(4):895-904. · 3.41 Impact Factor
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ABSTRACT: To investigate whether Unverricht-Lundborg disease (ULD) and Lafora body disease (LBD) can be differentiated on the basis of their neurophysiologic profiles.
Somatosensory evoked potentials (SSEPs), long-loop reflexes (LLRs), and the influence of conditioning nerve stimulation on the motor potentials evoked by transcranial stimulation in 8 patients with LBD and 10 patients with ULD were investigated.
Both groups showed sensorimotor cortex hyperexcitability, but their electrophysiologic profiles were different. Enlarged P25 to N33 SSEP components and enhanced LLRs were common in the ULD patients, whereas medium-latency "giant" SSEP components and less consistently enhanced LLRs were more frequently found in the patients with LBD. Cortical relay time was extremely brief in ULD but varied in LBD. Conditioning somatosensory stimuli differently affected motor cortex excitability, leading to early facilitation in ULD and delayed and prolonged facilitation in LBD.
Patients with Unverricht-Lundborg disease (ULD) and Lafora body disease (LBD) have different electrophysiologic profiles. The ULD findings point to an aberrant subcortical or cortical loop (possibly short-cutting the somatosensory cortex) that is involved in generating the prominent action myoclonus characterizing the disorder. The LBD findings highlight sustained hyperexcitability of the sensorimotor cortex in response to afferent stimuli, which fit with a more severe impairment of inhibitory mechanisms.
Neurology 01/2005; 63(12):2309-15. · 8.31 Impact Factor
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ABSTRACT: Subcortical nodular heterotopia (SNH) associated with refractory epilepsy may be surgically treated, and a positive outcome can be expected following the complete excision of the malformed tissue. Recent functional neuroimaging studies have suggested the possible functional relevance of cerebral malformations, and may make it possible to improve presurgical planning, thus allowing extended resections and minimising post-operative deficits. We here report the case of a 19-year-old man with epilepsy and a giant SNH associated with diffused abnormal gyrations of the right temporal-parietal regions. Cortical functional organisation was investigated by means of functional magnetic resonance imaging (MRI) during sensory and motor tasks, and somatosensory evoked potentials. The results revealed enlarged and displaced motor and sensory cortical areas with heterotopic tissue functional activation. The relevance of these findings is discussed in the light of the possible surgical treatment of drug-refractory epilepsy associated with cerebral malformations: surgical treatment based on conventional MRI studies alone, without taking the functional nature of dysplastic tissues into account, may lead to considerable side effects.
Neurological Sciences 11/2004; 25(4):225-9. · 1.32 Impact Factor
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D Pareyson,
E Dell’Anna,
T DiMonda, V Scaioli,
C Ciano,
A Sghirlanzoni,
G Lauria,
M Morbin,
M Laurà,
A Solari,
F Taroni
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ABSTRACT: Progesterone increases PMP22 expression. Transgenic rats overexpressing PMP22, a model of Charcot-Marie-Tooth type 1A (CMT1A), improve when treated with the progesterone antagonist, onapristone, and worsen with progesterone administration. CMT worsening during pregnancy (when progesterone secretion increases dramatically) has been occasionally reported. We investigated whether gender and pregnancy influence disease severity and course in CMT1A. We analyzed clinical and electrophysiological data of 94 CMT1A patients. Data in males and females were compared. We also determined disease severity in female patients in the fertile age as compared to males of the same age group. We retrospectively assessed influence of gestation on disease course in 20 CMT1A females through a comprehensive interview. There was no significant difference in disease severity in females as compared to males. Skeletal deformities, abnormalities of gait and deep tendon jerks, wasting, weakness, and sensory impairment were similar in the two genders. Nerve conduction abnormalities and decrease of sensory and motor evoked response amplitudes were comparable in the two groups. We found no difference in disease severity even when considering 15 to 50-year-old patients. Symptom worsening during pregnancy was reported by 4/20 CMT1A females. The effect of sex hormones on PMP22 does not result in a relevant difference in disease severity between the two genders. A few patients reported some worsening during pregnancy. Disease and normal controls need to be evaluated to establish whether this is a CMT1A-related phenomenon.
Journal of the Peripheral Nervous System 04/2004; 9(2):118 - 118. · 2.80 Impact Factor
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ABSTRACT: We investigated the association between clinical and neurophysiological characteristics in patients with a clinical diagnosis of probable corticobasal degeneration (CBD), and searched for neurophysiological features supporting the diagnosis in life. Ten patients with clinically probable CBD underwent comprehensive neurological evaluation and brain MRI. Long latency reflexes (LLR), upper limb somatosensory (SEP) and motor evoked (MEP) potentials were recorded. The mini-mental state examination (MMSE), the phonemic verbal fluency test (PVFT) and the De Renzi ideomotor apraxia test were also performed. Polygraphic EEG was performed in the six patients with myoclonus. The SEP N30 frontal component was absent bilaterally in four patients, was absent on the left side in one, and had increased latency in other three. MEPs were abnormal in four patients (three had prolonged central motor conduction time, one of whom also had increased MEP threshold, and one had increased MEP threshold). All six patients with myoclonus had enhanced LLRs at rest, which were also of abnormally increased amplitude during motor activation; latencies were generally shorter than in classic cortical reflex myoclonus. On back-averaging, no EEG spikes time-locked to EMG activity were found in any myoclonus patient. Five patients were demented by MMSE, eight had ideomotor apraxia scores in the ideomotor apraxia range and five had defective verbal fluency. Brain MRI revealed asymmetric cortical atrophy in all patients, particularly evident frontoparietally. Neurophysiological techniques, particularly LLR, can assist CBD diagnosis especially in patients with myoclonus. Patients with evident parkinsonism had greater SEP N30 (frontal) abnormalities, while most patients with marked paresis had slower MEP times.
Neurological Sciences 05/2003; 24(1):16-23. · 1.32 Impact Factor
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D Pareyson, V Scaioli,
M Milani,
C Ciano,
I Moroni,
M Morbin,
A Erbetta,
L Chiapparini,
G Lauria,
A Sghirlanzoni,
F Taroni
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ABSTRACT: The X-linked form of Charcot-Marie-Tooth disease (CMTX) is associated with mutations in the Connexin 32 gene (Cx32) and is the second most common CMT subtype after CMT1A, in which the 17p11.2 duplication is the underlying molecular defect. CMTX is characterized by no male-to-male transmission, intermediate motor conduction velocities (MCV), and more severe disease in males. In our series of CMT patients, we found 9 different Cx32 mutations in 11 families. Overall there were 26 patients, 13 males and 13 females, aged 11–76 yrs. Age at onset ranged considerably (1–60 yrs), but symptoms began earlier in males (mean 15.4 yrs, 77% within age 20) than in females (mean 25 yrs). All patients were autonomous, but disease severity was greater in males, while 4 female carriers were asymptomatic. Pain and tremor were frequent complaints. Two patients had Babinski sign and one had rest tremor. Nerve conduction studies were performed in 23 patients (13 males, 10 females). Upper limb motor conduction velocities (MCV) ranged between 25 and 57 m/s, and were slower in males (25–48 m/s) than in females (34–57 m/s). MCV were in the upper range of CMT1 (25–38 m/s) in 10/13 males but only in 3/10 females. In some cases, nerve conduction slowing was non-uniform within single nerves, and one female patient had a previous diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy. There was considerable asymmetry of involvement between different nerves. The median nerve was often more severely affected than the ulnar nerve, and not only in females, as previously reported, but also in males. Therefore, it appears unlikely that this asymmetry is accounted for by a Lyonization phenomenon. Subclinical abnormalities of central nervous system as revealed by multimodal evoked potential studies were found in 8/10 patients. Expression of Cx32 in the brain is the likely explanation of this finding that confirms previous non-systematic observations. We found seven missense and two nonsense mutations (one novel mutation). Two families presented distinct mutations at the same codon (Arg164), while the Arg22Stop and Arg220Stop mutations were each found in two unrelated cases.Partially supported by a grant from the Italian Ministry of Health to F.T and D.P. (Progetto Ricerca Finalizzata ICS 030.3/RF00.174).
Journal of the Peripheral Nervous System 03/2003; 8(1):29 - 58. · 2.80 Impact Factor
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ABSTRACT: Few muscle disorders can be diagnosed by repetitive nerve stimulation (RNS). Decreasing compound muscle action potentials (CMAP) on high frequency RNS is recorded in muscle channelopathies, and particularly in sporadic and recessive congenital myotonia. In this myopathy, decreasing CMAP after exercise test and RNS are the most sensitive electrophysiological in detecting muscle membrane dysfunction and are considered highly informative even in mildly symptomatic patients. We report on a patient with excercise-induced diffuse muscle cramps and myalgia; muscle biopsy and laboratory investigations were normal. Decreasing CMAP on high frequency RNS suggested muscle membrane conduction anomalies and, though clinical and electrical myotonia was not detected, the neurophysiological finding raised the suspicion of congenital myotonia and addressed to molecular investigation.
Electromyography and clinical neurophysiology 10/2002; 42(6):333-6.
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International Review of Neurobiology 02/2001; 45:159-72. · 2.35 Impact Factor
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ABSTRACT: The importance of visual evoked potentials (VEPs) and electroencephalography for diagnosing and distinguishing the infantile (INCL), late-infantile (LINCL) and juvenile (JNCL) forms of neuronal ceroid lipofuscinoses (NCL) is well established. Variant forms with protracted clinical courses and atypical symptoms have been described recently, whose neurophysiological characteristics sometimes overlap those of LINCL and JNCL. It is unclear whether these variant forms are due to phenotypic variability of known genetic defects, or represent new mutations. Twenty-eight NCL patients have been diagnosed at our institute; a proportion of them were investigated genetically. In 17 we performed neurophysiological investigations including VEPs, brainstem auditory (BAEP) and upper limb somatosensory (SEP) evoked potentials. We found typical and diagnostic electrophysiological involvement of the visual system in 8 patients with classic forms of NCL. Furthermore, the distinctive features of the multimodal evoked potentials in most of the six patients with variant NCL suggest that these are distinct genetic entities.
Neurological Sciences 02/2000; 21(3 Suppl):S89-92. · 1.32 Impact Factor
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ABSTRACT: Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder characterized by recurrent mononeuropathies or brachial plexopathies, commonly associated with a chromosome 17p11.2-12 deletion encompassing the peripheral myelin protein-22 (PMP22) gene. We tried to identify criteria distinguishing HNPP among patients with acute painless mononeuropathy/plexopathy. We investigated by pulsed-field gel electrophoresis the presence of the deletion in 27 patients with isolated or recurrent acute painless mononeuropathy or brachial plexopathy, and no obvious cause of neuropathy. Eight patients carried the deletion, whereas 19 had neither the deletion nor mutations in the PMP22 gene. Age at onset, presenting modality, precipitating events, and rate of recovery did not significantly differ in the two groups. Family history was informative for HNPP diagnosis in 3 cases only. HNPP patients more often showed recurrent episodes, brachial plexopathy, and clinical or electrophysiologic involvement of other nerves. Non-HNPP patients more frequently had peroneal palsy, recent weight loss, and normal electrophysiologic examination in other nerves. Signs of generalized neuropathy and evidence of disease in other family member are often subtle in HNPP and must be thoroughly investigated in patients with acute painless mononeuropathy/plexopathy.
Muscle & Nerve 01/1999; 21(12):1686-91. · 2.37 Impact Factor
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ABSTRACT: We performed electroencephalography (EEG) and multimodal evoked potential (EP) studies in 16 patients with various forms of mitochondrial encephalomyopathy (ME). The electrophysiological investigations revealed signs of involvement of the peripheral and central nervous system (CNS) in 14 patients, with a high incidence of visual-EP (VEP) alterations, indicative of visual pathway vulnerability in mitochondrial diseases. No specific pattern of abnormalities emerged and, in particular, clinical and laboratory findings did not correlate with each other. EP (particularly VEP and electroretinogram) investigations should be part of the diagnostic work-up of patients with mitochondrial disorders in order to better characterize the clinical picture, disclose involvement of specific sensory systems of the CNS, and assess patients with atypical clinical presentations.
The Italian Journal of Neurological Sciences 11/1998; 19(5):291-300.
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ABSTRACT: Five patients with unilateral myoclonus and a clinical diagnosis of corticobasal degeneration (CBD) were studied. All patients showed enhanced long-loop responses in their myoclonic arms without enlarged somatosensory potentials. The cortical relay time of the long-loop responses was studied in three patients, in two of whom it was < 2 ms, even in the nonmyoclonic arm. Myoclonus in CBD is probably related to an enhanced long-loop reflex whose pathway is unlikely to be the same as that in classic cortical reflex myoclonus.
Movement Disorders 07/1997; 12(4):598-603. · 4.51 Impact Factor
