RESUMO
The simultaneous and involuntary displacement of the opposite limb during a volitional movement is called mirror movements. They mimic the gesture, partly or wholly. They can be congenital, familiar or installed in various CNS pathologies. We present a 64 years old woman with familiar history of mirror movements that affect their hands, since childhood. At admission presented confused with left hemiplegia and homolateral sensory involvement. The brain CT defined a right ischemic stroke affecting the posterior limb of the internal capsule, lenticular nucleus, sub insular region and par ventricular white matter. The paretic left hand, unable to perform voluntary movements, presented mirror movements during volitional movements of the contra lateral hand. Neurophysiologic studies have suggested that mirror movements are due the activation of the direct corticospinal pathway or simultaneous discharge of both motor cortexes due inhibitory pathways failures. Cortical origin seems unlikely for the movements in this patient, due to the injury of the internal capsule. Our case could be interpreted by the simultaneously brain innervations on both anterior horns, together with a congenital deregulation of the Central Pattern Generator Networks.
Se denomina movimiento en espejo (ME) el desplazamiento involuntario, imitativo y simultáneo de la extremidad opuesta al de un movimiento volitivo. Los ME pueden tener un origen congénito y familiar o generarse por patologías diversas del sistema nervioso central. Se presenta una mujer de 64 años con el antecedente de ME desde la infancia de carácter familiar. Ingresa en estado confusional y presentando una hemiplejía y hemihipoestesia faciobraquicrural izquierda. La tomografía cerebral mostraba compromiso del brazo posterior de la cápsula interna, núcleo lenticular, región subinsular y de la sustancia blanca paraventricular. La mano izquierda pléjica que era incapaz de realizar movimientos voluntarios, se movía en espejo al mover la mano derecha. Esta curiosa manifestación hace necesario una más ajustada interpretación neurofisiológica de los movimientos en espejo. Se ha postulado una activación de la vía corticoespinal directa, o la descarga simultánea de ambas cortezas motoras por fallas en la natural inhibición transcortical. En este caso parece improbable un origen cortical contralateral de los movimientos, debido a la lesión de la cápsula. Tal vez podrían comprenderse los ME de esta paciente, si se demostrara una doble inervación de ambas astas anteriores, asociada a una falla en la inhibición normal por desregulación congénita de los Circuitos Generadores Centrales.
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Hemiplegia/diagnóstico , Infarto Cerebral/complicações , Transtornos dos Movimentos/congênito , Transtornos dos Movimentos/fisiopatologia , Acidente Vascular Cerebral/complicações , Lateralidade Funcional , Mãos/fisiopatologia , Reflexo , Sincinesia , Sistema Nervoso Central/fisiopatologiaRESUMO
INTRODUCTION: Mirror movements (MM) are involuntary shudders which occur at the same time as voluntary movements of the homologous contralateral muscles. They may occur alone or associated with other pathology. CLINICAL CASES: We present three new cases of congenital MM (CMM) and discuss their clinical, physiopathological and genetic aspects. Case 1. A four year old boy was brought to the clinic because he dropped things held in one hand when he tried to take things with the other. On examination it was seen that when he made a voluntary movement with one hand, the other hand made a similar movement simultaneously and involuntarily. This phenomenon had been observed since he was a few months old. Apart from this, the rest of the neurological examination was normal. Cerebral MR was also normal. Neuropsychological assessment showed borderline intellectual function. Case 2. The first patient's father, who was 26 years old, knew no details of his own family history. Since childhood he had noticed that he himself had made similar movements to those of his son. However, with time, he had managed to partially control and even inhibit these movements. His cerebral MR scan was normal. Case 3. An 11 year old boy consulted for MM, non-fluctuating congenital palpebral ptosis and nocturnal enuresis. The neurological examination and his intelligence were found to be normal. One of his sisters had palpebral ptosis and nocturnal enuresis without MM. His cerebral MR, X-ray of his spine, EMG, electroretinogram, CPK, blood lactate, glucemia, urine and urological examination were normal. CONCLUSIONS: MM may be another manifestation within the clinical spectrum of diverse encephalopathies; may be associated with different syndromes (Kallman, Klippel-Feil and Usher amongst others) or may present alone. Both familial and sporadic cases have been described. We consider our cases 1 and 2 to be of the familial CMM condition, with autosomal dominant inheritance, in which MM was the only finding. The association observed in case 3 has not previously been described. It may possibly be a condition transmitted by autosomal recessive inheritance.