Neuropatía hereditaria con susceptibilidad a la parálisis por presión: importancia del protocolo electrodiagnóstico / Hereditary neuropathy with liability to pressure palsies. Importance of electrodiagnostic protocol

Introduction: Hereditary neuropathy with susceptibility to pressure palsy is a genetic disorder of autosomal dominant inheritance that affects mainly the peripheral nerve myelin. This work aims to give a detailed description of a peculiar case and a literature review. Method: Neurophysiological and genetic study of 21 years old patient referred to the Clinical Neurophysiology Unit, by paresthesia in the right ulnar nerve territory. Results: Electromyographic examination demonstrated the existence of a sensory-motor polineuropathy greater intensity in multiple locations susceptible to nerve entrapment and genetic study confirmed the existence of a deletion at the PMP22 gene (chromosome 17p11.2). Conclusions: Hereditary neuropathy with susceptibility to pressure palsy is an underdiagnosed disease that may go unnoticed by simulating a simple compressive neuropathy. A rigorous neurophysiological study is essential to carry out a suspected diagnosis and to guide subsequent genetic diagnosis.

Introducción: La neuropatía hereditaria con susceptibilidad a la parálisis por presión es un trastorno genético de herencia autosómica dominante que afecta principalmente a la mielina de los nervios periféricos. Con este trabajo se pretende por un lado hacer una descripción detallada de un caso peculiar resaltando la importancia del protocolo electrodiagnóstico además de realizar una revisión bibliográfica sobre el tema. Método: Estudio neurofisiológico y genético de paciente de 21 años remitido a la Unidad de Neurofisiología Clínica por parestesias en territorio del nervio cubital derecho. Resultados: La exploración electromiográfica objetivó la existencia de una polineuropatía sensitivo-motora de predominio desmielinizante y mayor intensidad en localizaciones susceptibles al atrapamiento nervioso y el estudio genético confirmó la existencia de una deleción a nivel del gen PMP22 (cromosoma 17p11.2). Conclusiones: La neuropatía hereditaria con susceptibilidad a la parálisis por presión es una enfermedad infradiagnosticada que puede pasar desapercibida simulando una simple neuropatía compresiva. Un riguroso estudio neurofisiológico es fundamental para llevar a cabo un diagnóstico de sospecha así como para orientar el posterior diagnóstico genético.

Autosomal dominant HMSN with proximal involvement: new Brazilian cases / HMSN autossômica dominante com envolvimento proximal: novos casos brasileiros

We report four Brazilian siblings with Autosomal Dominant Hereditary Motor Sensory Neuropathy with Proximal Dominant Involvement (HMSN-P), a rare form of HMSN, that was characterized by proximal dominant muscle weakness and atrophy onset after the age of 30 years, fasciculation, arreflexia and sensory disturbances with autosomal dominant inheritance. Electrophysiological study and sural nerve biopsy were in the accordance with axonal sensory motor polyneuropathy and laboratorial analysis disclosed serum lipids and muscle enzymes abnormalities. Our report is the first done by a group outside Japan, where the disease initially seemed to be restricted and stressed the phenotypic variability from the original report.

Relatamos os casos de quatro irmãos brasileiros com Neuropatia Sensitivo Motora Hereditária com Envolvimento Proximal Dominante (HMSN-P), uma forma rara de HMSN caracterizada por fraqueza muscular de predomínio proximal e atrofia de instalação após os 30 anos, fasciculações, arreflexia, distúrbios sensitivos e padrão de herança autossômica dominante. Os estudos eletrofisiológicos e de biópsia do nervo sural confirmaram o diagnóstico de polineuropatia sensitivo-motora com padrão lesional axonal. Laboratorialmente foram constatadas anormalidades séricas no metabolismo lipídico e enzimas musculares. Nosso relato é o primeiro feito por um grupo fora do Japão, onde a doença parecia restrita até então e ressalta a variabilidade fenotípica apresentada nos casos Brasileiros.

Neuropatía hereditaria con predisposición a la parálisis por compresión: presentación de casos clínicos y electrofisiológicos / Hereditary neuropathy with liability to pressure palsies: presentation of clinical and electrophysiological cases

Hereditary neuropathy with liability to pressure palsies (HNPP) is a rare autosomal dominant neuropathy characterized by recurrent episodes of painless multiple nerve entrapments. We present five cases of HNPP confirmed by clinical and electrophysiological studies. Genetic confirmation of the diagnosis was performed in only one of the cases, given the fact that there are no laboratories performing this test inChile. This emphasizes the importance of electrophysiological diagnostic suspicion and the need for electrophysiological studies in family members even when asymptomatic.

Electrophysiogical findings in a family with hereditary neuropathy and liability to pressure palsies

Hereditary neuropathy with liability to pressure palsies is an autosomal dominant and demyelinative peripheral neuropathy which characterized by reversible episodes of sensorimotor deficits after neural compression injuries. Their clinical hallmarks are recurrent and painless focal neuropathies maintly preceded by minor trauma or compression at entrapment sites of peripheral nerves. We describe multiple compression mononeuropathies in an individual who presented with left sided ulnar palsy after drilling for a period of 8 hours and report neurophysiologic findings in two clinically asymptomatic family members. We believe that this entity may be clinically and neurophysiologically underdiagnosed by orthopaedic surgeons and electromyographers. Electrophysiological abnormalities can be detected even in asymptomatic patients and it should be considered in differential diagnosis of patients with atypical presentations of compression neuropathies

Effectiveness of Real-Time Quantitative PCR Compare to Repeat PCR for the Diagnosis of Charcot-Marie-Tooth Type 1A and Hereditary Neuropathy with Liability to Pressure Palsies

The majority of cases of Charcot-Marie-Tooth type 1A (CMT1A) and of hereditary neuropathy with a liability to pressure palsies (HNPP) are the result of heterozygosity for the duplication or deletion of peripheral myelin protein 22 gene (PMP22) on 17p11.2. Southern blots, pulsed-field gel electrophoresis (PFGE), fluorescence in situ hybridization (FISH) and polymorphic marker analysis are currently used diagnostic methods. But they are time-consuming, labor-intensive and have some significant limitations. We describe a rapid real- time quantitative PCR method for determining gene copy number for the identification of DNA duplication or deletion occurring in CMT1A or HNPP and compare the results obtained with REP-PCR. Six patients with CMT1A and 14 patients with HNPP [confirmed by Repeat (REP) -PCR], and 16 patients with suspicious CMT1A and 13 patients with suspicious HNPP [negative REP-PCR], and 15 normal controls were studied. We performed REP-PCR, which amplified a 3.6 Kb region (including a 1.7Kb recombination hotspot), using specific CMT1A-REP and real-time quantitative PCR on the LightCycler system. Using a comparative threshold cycle (Ct) method and beta-globin as a reference gene, the gene copy number of the PMP22 gene was quantified. The PMP22 duplication ratio ranged from 1.35 to 1.74, and the PMP22 deletion ratio from 0.41 to 0.53. The PMP22 ratio in normal controls ranged from 0.81 to 1.12. All 6 patients with CMT1A and 14 patients with HNPP confirmed by REP-PCR were positive by real-time quantitative PCR. Among the 16 suspicious CMT1A and 13 suspicious HNPP with negative REP-PCR, 2 and 4 samples, respectively, were positive by real-time quantitative PCR. Real-time quantitative PCR is a more sensitive and more accurate method than REP-PCR for the detection of PMP22 duplications or deletions, and it is also faster and easier than currently available methods. Therefore, we believe that the real-time quantitative method is useful for diagnosing CMT1A and HNPP.

Congenital hypomyelinating neuropathy.

An eleven-month-old baby born out of non-consanguineous parentage presented with history of delayed motor milestones. The weakness was predominantly distal; there was intercostal muscle weakness, generalized hypotonia and areflexia. The nerve conduction velocities were unobtainable in all the four limbs. Sural nerve biopsy was consistent with the diagnosis of congenital hypomyelinating neuropathy, a rare form of hereditary motosensory neuropathy.

La neuropatía sensitiva motora hereditaria: un artículo de revisión bibliográfica / The hereditary sensitive motors neuropaties: a bibliograpic review of article

En este trabajo se hace una descripción didáctica de un grupo de neuropatías englobadas en el término de neuropatías sensitivas motoras hereditarias. Después de dar datos para el diagnóstico de los 7 tipos presentes se analiza la enfermedad de Charcot Marie Tooth como la más frecuente, desde el punto de vista diagnóstico, patogénico y de tratamiento

Hipertrofias nodulares y homogéneas de la cola de caballo / Nodular hypertrophy and homogeneous of the horsetail

Se presentan dos casos de hipertrofia de la cola de caballo, una en forma homogénea y otra en forma nodular, tratándose el primer caso de una hipertrofia de las raíces correspondientes a la variedad de neuritis intersticial de Dejerine-Sotta y el otro caso era múltiples metástasis en forma nodular a lo largo de las raíces sin encontrar el primario

Neuropatía amiloidea hereditaria: forma predominantemente disautonómica / Hereditary amyloid neuropathy with dysautonomic dysfunction

Presentamos un paciente de 38 años, quien consultó por presentar desde 6 años antes impotencia sexual, diarrea, hipotensión postural y parestesias en miembros inferiores. Tenía antecedentes familiares de cuadros similares. El diagnóstico clínico de neuropatía amiloidea hereditaria fue sospechado frente a una neuropatía periférica, con disautonomía y antecedentes familiares. La biopsia de nervio periférico confirmó el diagnóstico. Nosotros nos preguntamos si la disfunción disautonómica tan severa de nuestro paciente es otra variedad de neuropatía amiloidea hereditaria o sólo una variante del tipo I de Corino Andrade

Doença de Thévenard / Thevenard disiase

A doença de Thévenard ou acropatia ulceromutilante familial é uma síndrome autossômica dominante composta de neuropatia sensorial e alteraçoes tróficas dos membros inferiores. A sintomatologia pode iniciar-se em qualquer período da infância. A reduçao da sensibilidade é bilateral e simétrica, enquanto a motricidade permanece intacta. Dois novos casos sao descritos.