1. Introduction
Congenital mirror movement disorder, involuntary movements on one side of the body that occur as mirror of the intentional movements on the contralateral side, is an autosomal-dominant or sometimes sporadic disease. Mirror movements (MM) may be associated with many diseases like cerebrovascular disease, Klippel-Feil syndrome, corpus callosum dysgenesis, Moebius syndrome, septo-optic dysplasia and Kallman syndrome (1-5).
Colpocephaly is described as persistence of fetal configuration of lateral ventricles. It has been found in association with absent corpus callosum (6, 7).
Although in the literature association of colpocephaly and congenital mirror syndrome is not reported, both diseases are shown to be in association with corpus callosum dysgenesis. Herein we report a case with congenital mirror movements, colpocephaly, corpus callosum hypogenesis and attention deficit hyperactivity disorder (ADHD). So far it is the first case reported in the literature with association of ADHD and congenital mirror movements, colpocephaly and/or corpus callosum dysgenesis.
2. Case Presentation
Parents of this 2-month old male infant were complaining of bilateral identical movements of the hands of the child. He was born to healthy and non-consanguineous parents by spontaneous delivery at 37th gestational week with 2,950 gr birth weight, 49 cm birth length. There was no family history. He was breast feeding. The physical examination was normal. A complete physical and neurological examination was performed and mirror movements were assessed according to the Woods and Teuber grading scale (8). Except for bilateral involuntary synkinetic imitative movements in hands, neurological examination was normal. Amplitude of the intentional movements were greater than involuntary movements of the contralateral hand. At first, transfontanel ultrasonograhy was performed to evaluate brain which showed corpus callosum hypogenesis and then cranial MRI was performed to assess brain exactly. Corpus callosum dysgenesis, hypogenesis and dilation of bilateral lateral ventricular posterior horns (colpocephaly) were detected. The patient was asymptomatic except for mirror movement of the hands. On follow-up, he started to walk at 13 months and started to say one word nearly at 15 months of age. He was cooperating well. Motor-mental developmental steps were appropriate for his age.
At the age of 7 years, he was referred to child psychiatrist because of hyperactivity and inability to concentrate in the school. After psychiatric evaluation he was started to use metylphenydate due to attention deficit and hyperactivity syndrome. He was free of symptoms after 1 year of metylphenydate treatment. No other serious physical or psychological disease occured. The mirror movements were decreasing in amplitude by years and were not so serious to affect normal life activities.
3. Discussion
Mirror movements are usually diagnosed during childhood (9). Mirror movements may be congenital or secondary to neurological diseases (7, 10, 11). Although they generally do not affect normal life activities, in some cases severity of MM causes a real debilitating disease. In our case the patient was diagnosed at the age of 2 months and on follow-up no debilitating problems were observed.
The pathopysiology of the mirror movements has not been exactlly elucidated yet. Pathophysiological mechanism of MM depends on the pathological condition. Jain et al. (12) showed that the mirror movement-like deficits are associated with defect of axonal guidance in two identifed groups of commisural reticulospinal hindbrain neurons. Zebrafish dcc mutants were used to clarify this pathway. Axons of these neurons usually do not cross the midline and project ipsilaterally. Overactivation of ipsilateral corticospinal tract is the major hypothesis (11). In some cases, as in our patient, the association of corpus callosum dysgenesis and MM was illustrated which may elucidate the hypothesis of Jain et al. (12) and Rasmussen (11).
Colpocephaly is disproportionate enlargement of the occipital horns of the lateral ventricles. It is usually associated with multiple neurological syndromes including agenesis of the corpus callosum (9). It is assumed to occur as a result of neuronal migration disorders during early brain development and other central nervous system disorders (13). There is no known association of colpocephaly and MM in the literature. Our case is the first to describe the association of colpocephaly and MM. The exact mechanism of this association is not known. It may be an association or just an incidence of comorbidities. Cases reported about this association will help to clarify the mechanism.
Although it is known that MM may be in relation with some pychiatric diseases, this is the first report of ADHD in conjunction with MM and/or colpocephaly (14). When the parents of the patients with MM and/or colpocephaly suffer from hyperactivity and unsuccess of learning new things, the child should be evaluated for ADHD. Unfortunately, up to date, there is no really effective treatment for MM or colpocephaly. So managing comorbidities like ADHD, either physically or psychologically, will help the patient to live in good health without trying to cope with other pathological diseases.
