Home Acmt-Rete C.M.T. Strumpell-LorrainMedcenterNews | ForumContatti LinksRuotHabile | Le Nostre Storie

 

Ti trovi in: Home > News > Ultime ricerche 2004

 

 

 

U L T I M E       R I C E R C H E

Aggiornate con notizie provenienti dalla rete e dai centri di Ricerca Medica italiani e stranieri

DESCRIZIONE

La malattia di Charcot-Marie-Tooth (CMT) di tipo 4B

NOTIZIA

Roma, 3 dicembre 2004

COMUNICATO STAMPA - RICERCA TELETHON:

ECCO PERCHÉ LA MALATTIA DÀ AI NERVI

 

Ricercatori Telethon chiariscono i meccanismi molecolari  di una forma

della malattia di Charcot-Marie-Tooth. Ora è più facile pensare a un rimedio

 

L’unione fa la forza. E i risultati si vedono. Ricercatori finanziati da Telethon hanno capito che cosa scatena la malattia di Charcot-Marie-Tooth (CMT) di tipo 4B, la forma recessiva che, insieme alle altre forme della neuropatia, rappresenta la malattia ereditaria più frequente del sistema nervoso periferico, colpendo circa 1 persona su 2.500. Sui nervi si deposita troppa mielina, il nastro isolante che riveste i nervi periferici prodotto dalle cosiddette cellule di Schwann: queste si allineano lungo i bracci delle cellule del sistema nervoso periferico e li avvolgono isolandoli per consentire la trasmissione veloce dell’impulso elettrico. Ma quando la mielina è in eccesso si dispone in modo caotico facendo diminuire la velocità di conduzione nervosa. La scoperta è stata pubblicata sul prestigioso The Journal of Cell Biology*.

Per arrivare a questa risposta ci sono voluti diversi anni, ma adesso la strada sembra solo in discesa. Nel 1989 alcuni ricercatori avevano intuito che cosa non andava nella malattia, ma solo oggi, a 15 anni di distanza, Alessandra Bolino, ricercatore dell’Istituto Telethon Dulbecco che lavora al Dibit-Istituto San Raffaele di Milano, in stretta collaborazione con Lawrence Wrabetz presso lo stesso Istituto, hanno chiarito il meccanismo molecolare alla base della malattia. Anche i topolini si possono ammalare di CMT4B e questo ha consentito ai ricercatori di vedere da vicino quali sono gli effetti della malattia nelle cellule, nei tessuti e negli organi danneggiati. Alessandra Bolino, sotto l’egida di Telethon, ha scoperto quattro anni fa che il difetto all’origine della malattia risiede in Mtmr2, un gene per una fosfatasi, un enzima che sottrae dei gruppi chimici (fosfati) da alcune proteine per controllarne l’attività. I topolini sono più fortunati dell’uomo, perché la malattia è meno grave e ciò ha permesso di guardare nel modello animale quello che succede ai nervi malati. E i risultati non si sono fatti attendere, primo tra tutti il ruolo di Mtmr2 nel difetto a carico della mielina, ma non solo: si è visto per la prima volta nelle cellule di Schwann che la proteina prodotta da Mtmr2 interagisce con una “collega” chiamata Dlg1, una proteina che aiuta la cellula a orientarsi nello spazio; senza Mtmr2 e quindi senza il contributo di Dlg1, le cellule sono disorientate, come se stessero a testa in giù, e la mielina si dispone in modo disordinato. E ancora, l’assenza del gene responsabile causa difetti nella spermatogenesi, il processo che genera spermatozoi, come avviene anche nell’uomo.

Commenta la Bolino: “Il difetto alla base della neuropatia sta in un enzima e questo faciliterà l’approccio terapeutico; grazie a questo modello di neuropatia siamo riusciti a capire la biologia della malattia, le molecole coinvolte e quello che succede ai nervi malati”.

Il progetto ha usufruito anche di finanziamenti da parte della Compagnia di San Paolo e di SMA supermercati, ed è un esempio di ricerca che porta un contributo decisivo alla comprensione di una malattia genetica. Nonostante i notevoli risultati già raggiunti, il lavoro continua col massimo impegno: prossima tappa capire come l’eccesso di mielina intorno ai nervi ne impedisce il funzionamento.

******************

*Bolino A et al. J. Cell Biol. Nov 2004; 167:711-21

 

Per informazioni Dott.ssa Alessandra Bolino: Tel 348/7117598.

 E-mail: bolino.alessandra@hsr.it

 

Inizio pagina

DESCRIZIONE

Neuropatia periferica nei pazienti trattati con Leflunomide

NOTIZIA

Martedì 21 Settembre 2004, 10:05

Tratto da Farmacovigilanza.net
La Leflunomide (Arava) è un farmaco impiegato nel trattamento dell’artrite reumatoide.
Ricercatori del CDER / Drug Safety dell’FDA negli Usa, hanno analizzato le caratteristiche cliniche, il decorso e l’outcome (esito) della neuropatia periferica di nuova insorgenza dopo trattamento con Leflunomide.
All’FDA sono giunte
80 segnalazioni. Di queste, il 61% riguardava le donne. L’età media dei pazienti era di 62 anni. I sintomi della neuropatia periferica sono insorti in media dopo 6 mesi di impiego della Leflunomide (range: 3 giorni - 3 anni ).
Dal test elettrodiagnostico compiuto su
37 pazienti è emersa una polineuropatia sensorio motoria, o sensoria, o assonale distale.
I pazienti che hanno interrotto l’assunzione di Leflunomide entro
30 giorni dell’insorgenza dei sintomi della neuropatia hanno presentato una maggiore probabilità di miglioramento o di guarigione rispetto a coloro che invece hanno continuato ad assumere la Leflunomide per più lunghi periodi ( p < 0,001 ).
Secondo i ricercatori dell’FDA la Leflunomide è associata in alcuni casi a neuropatia periferica.
Fonte: Clin Pharmacol Ther
Per ulteriori informazioni visita Xagena.it

Inizio pagina

DESCRIZIONE

La chirurgia dell’obesità può causare neuropatia periferica

NOTIZIA

Lunedì 18 Ottobre 2004, 12:52                                                        

Tratto da MedicinaOnline.org
Un significativo numero di persone che si sottopongono a chirurgia dell’obesità possono andare incontro a grave neuropatia periferica.
Lo studio, compiuto presso la Mayo Clinic di Rochester negli Usa, ha preso in esame
435 pazienti che si erano sottoposti a chirurgia dell’obesità.
Il
16% ( n = 71 ) di questi pazienti ha sviluppato neuropatia periferica.
La causa alla base dello sviluppo della neuropatia è ritenuta essere la malnutrizione, probabilmente una deficienza di vitamina B
12. I pazienti che sono andati incontro a neuropatia periferica sono stati quelli che hanno perso più peso corporeo, ed in tempi più rapidi.
Inoltre i pazienti che sviluppano sintomi neurologici, tendono ad avere una maggiore incidenza di nausea, diarrea, e di rapido svuotamento gastrico.
La neuropatia in alcuni casi può condurre a disabilità permanente.
Fonte: Neurology
Per ulteriori informazioni visita
Xagena.it

Inizio pagina

DESCRIZIONE

Studi istologici sulla malattia di Charcot-Marie-Tooth tipo I con un test non invasivo

TESTO ORIGINALE

Preliminary Study of Large and Small Peripheral Nerve Fibers in Charcot-Marie-Tooth Disease, Type I
Hanson P, Deltombe - Am J Phys Med Rehabil
1998; 77(1):45-8
Histologic studies of Charcot-Marie-Tooth disease, type I, show a contrast between the lesions of myelinated fibers and the normality of unmyelinated fibers. Conventional electrophysiologic tests only demonstrate the alteration of myelinated fibers but do not study unmyelinated fiber function. We present routine clinical tests that are easily available and effective for the evaluation of small unmyelinated fibers: thermal threshold testing for warmth to evaluate small C unmyelinated somatic fibers and sympathetic skin responses to evaluate small C unmyelinated sympathetic fibers. Five unrelated patients with a diagnosis of Charcot-Marie-Tooth disease, type I, confirmed by biopsy were investigated. All of these patients showed marked reduction or absence of motor and sensory conduction velocities and severe denervation at needle examination. By contrast, thermal threshold testing for warmth and sympathetic skin responses were normal, confirming the normality of small C unmyelinated somatic and sympathetic fibers. We conclude that these noninvasive tests are helpful in the diagnosis of Charcot-Marie-Tooth disease, type I.

Inizio pagina

DESCRIZIONE

ELETTROMIOGRAFIA LARINGEALE

Nel tipo II C della malattia di Charcot-Marie-Tooth, di tipo assonale, presenta debolezza del diaframma e paralisi del cavo vocale. E’ stata usata l'elettromiografia laringeale per studiare un paziente con questo disordine. Questa tecnica è utile nella diagnosi del tipo II di malattia del Charcot-Marie-Tooth.

TESTO ORIGINALE

Laryngeal Electromyographic Findings in Charcot-Marie-Tooth Disease Type II - .Dray TG, Robinson LR, Hillel AD - Arch Neurol 1999; 56(7):863-5
Charcot-Marie-Tooth disease is a hereditary motor and sensory neuropathy that exhibits progressive muscular atrophy in the limbs, beginning with the lower extremities. It is now understood to be a heterogeneous group of disorders that can be differentiated both clinically and genetically. In Charcot-Marie-Tooth disease type II C, axonal neuropathy, diaphragm weakness, and vocal cord paralysis are described within kindreds. We used laryngeal electromyography to study a patient with this disorder. This technique has potential in the diagnosis of Charcot-Marie-Tooth disease type II.

Inizio pagina

DESCRIZIONE

Neuropatia ereditaria: i vari geni responsabili e loro suddivisione in tipi e sottotipi

TESTO ORIGINALE

Inherited Neuropathies: From Gene to Disease - Keller MP, Chance PF
Brain Pathol
1999; 9(2):327-41
Inherited disorders of peripheral nerves represent a common group of neurologic diseases. Charcot-Marie-Tooth neuropathy type
1 (CMT1) is a genetically heterogeneous group of chronic demyelinating polyneuropathies with loci mapping to chromosome 17 (CMT1A), chromosome 1 (CMT1B) and to another unknown autosome (CMT1C). CMT1A is most often associated with a tandem 1.5-megabase (Mb) duplication in chromosome 17p11.2-12, or in rare patients may result from a point mutation in the peripheral myelin protein-22 (PMP22) gene. CMT1B is associated with point mutations in the myelin protein zero (P0 or MPZ) gene. The molecular defect in CMT1C is unknown. X-linked Charcot-Marie-Tooth neuropathy (CMTX), which has clinical features similar to CMT1, is associated with mutations in the connexin32 gene. Charcot-Marie-Tooth neuropathy type 2 (CMT2) is an axonal neuropathy, also of undetermined cause. One form of CMT2 maps to chromosome 1p36 (CMT2A), another to chromosome 3p (CMT2B) and another to 7p (CMT2D). Dejerine-Sottas disease (DSD), also called hereditary motor and sensory neuropathy type III (HMSNIII), is a severe, infantile-onset demyelinating polyneuropathy syndrome that may be associated with point mutations in either the PMP22 gene or the P0 gene and shares considerable clinical and pathological features with CMT1. Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder that results in a recurrent, episodic demyelinating neuropathy. HNPP is associated with a 1.5-Mb deletion in chromosome 17p11.2-12 and results from reduced expression of the PMP22 gene. CMT1A and HNPP are reciprocal duplication/deletion syndromes originating from unequal crossover during germ cell meiosis. Other rare forms of demyelinating peripheral neuropathies map to chromosome 8q, 10q and 11q. Hereditary neuralgic amyotrophy (familial brachial plexus neuropathy) is an autosomal dominant disorder causing painful, recurrent brachial plexopathies and maps to chromosome 17q25.

Inizio pagina

DESCRIZIONE

Caso clinico di una frattura patologica della tibia nella CMT – siamo a rischio maggiore nelle fratture

TESTO ORIGINALE

Quintart C, Baillon JM, Libotte M - Acta Orthop Belg 1999; 65(1):105-8
The authors report a case of pathologic fracture of the distal tibia associated with Charcot-Marie-Tooth disease. Pathologic fracture was visible four weeks after initial pain. Treatment consisted in a short leg walking cast for six weeks. Charcot-Marie-Tooth disease is a slowly progressive neurogenic muscular atrophy affecting the distal parts of the lower limbs. The muscular atrophy is responsible for radiographic bony changes including narrowing of the shaft with thinning of the cortex, rarefaction at the end of the long bones and relative widening of the medullary cavity. Pathologic fractures in neuromuscular disease are rare; a few cases have been reported following application of very small forces. The authors draw attention to the increased risk of pathologic fractures in patients with neuromuscular disease. Ambulatory treatment of fractures should be used whenever possible; prolonged immobilization could result in further loss of function

Inizio pagina

DESCRIZIONE

Correlazione tra apatia e stanchezza cronica nelle neuropatie

TESTO ORIGINALE

Apathy and Hypersomnia Are Common Features of Myotonic Dystrophy - Rubinsztein JS, Rubinsztein DC, Goodburn S, Holland AJ - J Neurol Neurosurg Psychiatry 1998; 64(4):510-5
Objectives: Myotonic dystrophy is a disease characterised by myotonia and muscle weakness. Psychiatric disorder and sleep problems have also been considered important features of the illness. This study investigated the extent to which apathy, major depression, and hypersomnolence were present. The objective was to clarify if the apathy reported anecdotally was a feature of CNS involvement or if this was attributable to major depression, hypersomnolence, or a consequence of chronic muscle weakness.
Methods: These features were studied in
36 adults with non-congenital myotonic dystrophy and 13 patients with Charcot-Marie-Tooth disease. By using patients with Charcot-Marie-Tooth disease as a comparison group the aim was to control for the disabling effects of having an inherited chronic neurological disease causing muscle weakness. Standardised assessment instruments were used wherever possible to facilitate comparison with other groups reported in the medical literature.
Results: There was no excess of major depression on cross sectional analysis in these patients with mild myotonic dystrophy. However, apathy was a prominent feature of myotonic dystrophy in comparison with a similarly disabled group of patients with Charcot-Marie-Tooth disease (clinician rated score; Mann Whitney U test, p=
0.0005). Rates of hypersomnolence were greater in the myotonic dystrophy group, occurring in 39% of myotonic dystrophy patients, but there was no correlation with apathy.
Conclusion: These data suggest that apathy and hypersomnia are independent and common features of myotonic dystrophy. Apathy cannot be accounted for by clinical depression or peripheral muscle weakness and is therefore likely to reflect CNS involvement. These features of the disease impair quality of life and may be treatable.

Inizio pagina

DESCRIZIONE

Analisi sulla tossicità del farmaco Vincristine per i CMT – si tratta di un farmaco usato nelle neoplasie tumorali

TESTO INTEGRALE

Charcot-Marie-Tooth Disease Type I Diagnosed in a 5-Year-Old Boy After Vincristine Neurotoxicity, Resulting in Maternal Diagnosis - Olek MJ, Bordeaux B, Leshner RT
J Am Osteopath Assoc
1999; 99(3):165-7 Charcot-Marie-Tooth disease type 1, also known as hereditary motor sensory neuropathy type 1, is an uncommon autosomal dominant disease that causes destruction of peripheral nerves with a varied clinical course, but often leads to muscle weakness. If the peroneal muscle is involved, the patient may develop a characteristic slapping gait. The dose-limiting side effect of the chemotherapeutic agent vincristine is usually its neurotoxicity. We report the case of a 5-year-old patient with leukemia who developed an acute polyneuropathy after treatment with vincristine. Charcot-Marie-Tooth disease type 1 was diagnosed in the patient and, subsequently, in his mother only after vincristine toxicity was observed.

Inizio pagina

DESCRIZIONE

Indagine e studi ortopedici sulla patologia

TESTO ORIGINALE

The Charcot Joint
Zwipp H, Rammelt S, Dahlen C, Reichmann H - Orthopade
1999; 28(6):550-8
Charcot foot in its original sense is equivalent to stage
4 of hereditary motor and sensory neuropathy (HMSN) which is known as Charcot-Marie-Tooth disease since 1886. This entity, which can be subdivided into 3 groups including subgroups, predominantly begins during childhood and progresses slowly. The first symptom, often unnoticed by the patient for a long period, is weakness of the intrinsic foot muscles with consecutive hammer-toe formation and mobile pes cavus. Progredient atrophy of the peroneal, extensor, tibialis posterior and finally triceps surae muscles leads to fixed pes cavus varus excavatus with severe varus deformity of the hindfoot, secondary varus position of the talus at the ankle level and subsequent arthrosis of the medial compartment. Permanent varus deformity of the ankle almost invariably leads to stress fractures of the malleoli because of repetitive microtrauma (stage 5 of HMSN). Early detection of the disease with nerve conduction studies at clinical suspicion allows tibialis posterior transfer, correctional osteotomy of the hindfoot or arthrodesis of Chopart's or Lisfranc's joint and can postpone or prevent the otherwise inevitable triple arthrodesis which has a less favorable long-term prognosis. At stage 4 (manifest Charcot foot) and stage 5 (neuropathic fracture of the ankle) a reorientating ankle arthrodesis is advocated, with additional subtalar pathology correctional double arthrodesis becomes necessary. In diabetic arthropathy of the ankle (Type IV according to Sanders and Frykberg), which is often referred to as "Charcot Ankle", tibiocalcanear arthrodesis is indicated. In case of supervening infection or extensive necrosis a modified Pirogoff amputation is carried out as a salvage procedure. Doubled periods of non weight-bearing, immobilization and brace protection of the ankle help to reduce the frequently observed implant failure in both forms of osteoarthropathy. In addition to stable implants retrograde calcaneotalotibial transfixation with a Steinmann pin may help to protect the achieved result despite prolonged bone consolidation.

Inizio pagina

DESCRIZIONE

Particolare tipo di anestesia per il parto in una donna di 25 anni, con insufficienza respiratoria e CMT

TESTO ORIGINALE

Anaesthesia for Caesarean Section in a Patient With Charcot-Marie-Tooth Disease
Reah G, Lyons GR, Wilson RC - Anaesthesia
1998; 53(6):586-8
We describe the management of a
25-year-old primigravida with severe respiratory insufficiency secondary to Charcot-Marie-Tooth disease type I scheduled for Caesarean section. Incremental subarachnoid anaesthesia via a microcatheter was utilised. Mother and baby made an uneventful recovery and were discharged home on the tenth postoperative day.

 

Inizio pagina

DESCRIZIONE

Indagine sulla relazione che esiste tra forza muscolare ed abilità funzionali

TESTO ORIGINALE

Quadriceps Strength and Timed Motor Performances in Myotonic Dystrophy, Charcot-Marie-Tooth Disease, and Healthy Subjects
Lindeman E, Leffers P, Reulen J, et al. - Clin Rehabil
1998; 12(2):127-35
Background And Purpose: The leading hypothesis was that a relation exists between muscular strength and functional abilities. Therefore a study was undertaken to quantify such a relationship in a population of subjects with different muscular strengths. This population consisted of healthy subjects and subjects with slowly progressive neuromuscular disorders.
Methods: The study included
33 patients with myotonic dystrophy, 29 patients with Charcot-Marie-Tooth disease and 20 healthy subjects. Isokinetic and isometric knee torques were measured on an isokinetic dynamometer at various velocities. The following activities were timed: descending and ascending stairs, rising from a chair, rising from supine, walking at natural speed and walking at maximum speed.
Results: The population covered a wide range of the variables: whereas the healthy subjects performed best (i.e. had the highest knee torques and performed the activities most quickly), the myotonic dystrophy group included the subjects with the lowest knee torques. The natural logarithms (In) of isokinetic extension torque at the highest velocity (
120 degrees/s) and those of the time taken to perform the described activities showed the highest levels of correlation. It was found that after correction for age and weight, 56% (walking at natural speed) to 73% (descending stairs) of the variance in the In of the time taken could be attributed to the variance in the In of the torques.
Conclusion And Discussion: A strong relation between quadriceps strength and timed motor performances were demonstrated. The impact of strength reduction on time taken was most obvious in subjects with considerably decreased strength. Therefore, it is feasible to try to influence muscle strength in patients with relevant strength reduction in order to achieve better functional ability.

Inizio pagina

DESCRIZIONE

Un caso di displasia associate alla neuropatia CMT

TESTO ORIGINALE

Charcot-Marie-Tooth Disease Associated With Hip Dysplasia: A Case Report
Cucuzzella TR, Guille JT, MacEwen GD - Del Med J
1996; 68(6):305-7
A
31-year-old woman with a known history of hip dysplasia was found to have Charcot-Marie-Tooth disease following abnormal conduction studies done at the time of surgery. Physical examination in this patient was otherwise normal, and the diagnosis of Charcot-Marie-Tooth disease had not been previously considered. This report demonstrates the importance of keeping in mind the association between hip dysplasia and Charcot-Marie-Tooth disease.

Inizio pagina

DESCRIZIONE

Dalla Corea un caso di  una famiglia con sordità associate alla patologia

TESTO ORIGINALE

Neuromuscul Disord 2004 May;14(5):325-8     (ISSN: 0960-8966)

Joo IS; Ki CS; Joo SY; Huh K; Kim JW
Department of Neurology, Ajou University School of Medicine, Suwon, South Korea.

Charcot-Marie-Tooth disease with deafness is a clinically distinct entity and is associated with mutations or deletions in several genes including PMP22 gene. Here, we report a large family showing characteristic phenotypes of Charcot-Marie-Tooth type 1A along with deafness in an autosomal dominant fashion. We detected a sequence variation (c.68C>G) co-segregating with the disease phenotype and leading to a T23R missense mutation in PMP22.

Inizio pagina

DESCRIZIONE

Studi radiologici sul nervo craniale

TESTO ORIGINALE

Charcot-Marie-Tooth Disease: Extensive Cranial Nerve Involvement on CT and MR Imaging [In Process Citation]

AJNR Am J Neuroradiol 2004 Mar;25(3):494-7     (ISSN: 0195-6108)

Aho TR; Wallace RC; Pitt AM; Sivakumar K
Section of Neuroradiology, St. Joseph's Hospital and Medical Center, Barrow Neurologic Institute, Phoenix, AZ. Division of Neurology, Neuromuscular Diseases Section, St. Joseph's Hospital and Medical Center, Barrow Neurologic Institute, Phoenix, AZ.

Summary: We report a case of genetically verified Charcot-Marie-Tooth disease in which the patient had cranial nerve symptoms. CT and MR imaging demonstrated enlargement of several cranial nerves, as well as their skull-base foramina, with faint contrast material enhancement identified.

 

Inizio pagina

DESCRIZIONE

Una famiglia dell’Aquila (Italia) con lesioni cerebrali e CMT – L’ipotesi è un meccanismo di auto-immunità

TESTO ORIGINALE

Brain White Matter Lesions in an Italian Family with Charcot-Marie-Tooth Disease [epub ahead of print] [Record Supplied By Publisher]

Eur Neurol 2004 Apr 1;51(3):168-171     (ISSN: 0014-3022)

Sacco S; Totaro R; Bastianello S; Marini C; Carolei A
Department of Neurology, University of L'Aquila, L'Aquila, Italy.

Type 1A, the most common form of Charcot-Marie-Tooth (CMT1A) disease, is characterized by demyelination of the peripheral nervous system. So far, only a few cases of the disease with concomitant brain white matter lesions have been described. We report an Italian family with CMT1A disease, consisting of the proband and 4 affected members, presenting with concomitant brain white matter lesions at magnetic resonance imaging. The association is particularly fascinating and might depend on an autoimmune mechanism, not yet clarified. Copyright 2004 S. Karger AG, Basel.

Inizio pagina

Inizio pagina | News | Ultime ricerche 2004

Home Acmt-Rete C.M.T. Strumpell-LorrainMedcenterNews | ForumContatti LinksRuotHabile | Le Nostre Storie

Copyright @ 2002 by Acmt-Rete - Sito ottimizzato per Explorer 5/Netscape 6 o superiori - risoluzione video 800x600 o superiore.