Epileptic seizures, arthrogryposis, and migrational brain disorders: a syndrome?

Central and peripheral dysmyelination in a 3-year-old girl with ring chromosome 18

Myelin basic protein (MBP) contributes to peripheral and central nervous system myelin. Developmental myelinopathies exist on a clinical spectrum, but MBP is not included on leukodystrophy or CMT gene panels. This ring chromosome 18 case presents serial MRI and EMG/NCS, shedding light on the early clinical course of the disorder.

Arthrogryposis: an update on clinical aspects, etiology, and treatment strategies

Arthrogryposes - multiple joint contractures - are a clinically and etiologically heterogeneous class of diseases, where accurate diagnosis, recognition of the underlying pathology and classification are of key importance for the prognosis as well as for selection of appropriate management. This treatment remains challenging and optimally in arthrogrypotic patients should be carried out by a team of specialists familiar with all aspects of arthrogryposis pathology and treatment modalities: rehabilitation, orthotics and surgery. In this comprehensive review article, based on literature and clinical experience, the authors present an update on current knowledge on etiology, classifications and treatment options for skeletal deformations possible in arthrogryposis.

Surgical management of medically refractory epilepsy in patients with polymicrogyria

OBJECTIVE

Polymicrogyria (PMG) is a malformation of cortical development characterized by formation of an excessive number of small gyri. Sixty percent to 85% of patients with PMG have epilepsy that is refractory to medication, but surgical options are usually limited. We characterize a cohort of patient with polymicrogyria who underwent epilepsy surgery and document seizure outcomes.

METHODS

A retrospective study of all patients with PMG who underwent epilepsy surgery (focal seizure foci resection and/or hemispherectomy) at our center was performed by review of all clinical data related to their treatment.

RESULTS

We identified 12 patients (7 males and 5 female) with mean age of 18 (ranging from 3 months to 44 years) at time of surgery. Mean age at seizure onset was 8 years, with the majority (83%) having childhood onset. Six patients had focal, five had multifocal, and one patient had diffuse PMG. Perisylvian PMG was the most common pattern seen on magnetic resonance imaging (MRI). Eight patients had other cortical malformations including hemimegalencephaly and cortical dysplasia. Scalp electroencephalography (EEG) often showed diffuse epileptic discharges that poorly lateralized but were focal on intracranial electrocorticography (ECoG). Eight patients underwent seizure foci resection and four underwent hemispherectomy. Mean follow-up was 7 years (ranging from one to 19 years). Six patients (50%) were seizure-free at last follow-up. One patient had rare seizures (Engel class II). Three patients were Engel class III, having either decreased seizure frequency or severity, and two patients were Engel class IV. Gross total resection of the PMG cortex trended toward good seizure control.

SIGNIFICANCE

Our study shows that even in patients with extensive or bilateral PMG malformations, some may still be good candidates for surgery because the epileptogenic zone may involve only a portion of the malformation. Intracranial ECoG can provide additional localizing information compared to scalp EEG in guiding resection of epileptogenic foci.

Diagnosing arthrogryposis multiplex congenita: a review

Arthrogryposis multiplex congenita (AMC) refers either to a syndromic or to a nonsyndromic group of conditions with varied etiology and complex clinical features, including multiple congenital contractures in different body areas. Its etiology still remains unclear but generally any cause that leads to reduced fetal movement may lead to congenital contractures and in severe cases to fetal akinesia deformation sequence (FADS). It affects approximately 1 in 2-3000 live births with an approximately equal gender ratio. There are many known subgroups of AMC differing in signs, symptoms, and causes. The primary diagnosis is made when a lack of mobility and an abnormal position is noted in routine ultrasound scanning. Early diagnosis, prenatal evaluation, and further surveillance via image scanning (ultrasound and MRI) give the opportunity for family counseling concerning neonatal morbidity and mortality and labor or delivery planning. Better understanding of the ultrasound findings and the etiology of this clinical situation offers the opportunity for careful prenatal assessment.

An unexpected finding in a child with neurological problems: mosaic ring chromosome 18

Major neurological disorders may accompany rare chromosomal abnormalities. As an example of this rare condition, we present a case with microcephaly, mental retardation, developmental delay, hyperactivity, stereotypic movements, seizures and dysmorphic facial appearance in whom a mosaic ring chromosome 18 was found [45,XX,-18/46,XX,r(18)/46,XX,dicr(18)]. Although ring chromosome 18 phenotype has been known for a long time, this is the third reported patient with a dicentric ring chromosome 18 mosaicism. The presented case will contribute to the identification of the genotype-phenotype correlation in chromosome 18 anomalies.

A case of congenital bilateral absence of elbow flexor muscles: review of differential diagnosis and treatment

A 1-year-old boy presented to us with congenital inability to flex his elbow. He had bilaterally absent biceps brachii and brachialis muscles, a rare condition. We performed pedicle latissimus dorsi musculocutaneous flaps to the left and right volar upper arm at 21 and 24 months of age, respectively, to create elbow flexors. By 4 years of age, he had excellent elbow flexion bilaterally with strength grade in excess of 4.5. In addition to discussing our patient's treatment options, we discuss other potential causes of weak elbow flexion when faced with this clinical dilemma.

Club feet with congenital perisylvian polymicrogyria possibly due to bifocal ischemic damage of the neuraxis in utero

Club foot is a common congenital deformity, for which a neurogenic process in utero has been proposed in some severe forms, but in most cases its cause remain uncertain. We report on four patients with an unilateral (three cases) or bilateral (one case) clubfoot and a bilateral perisylvian cortical dysplasia. All had severe dysarthria with mild mental retardation, epilepsy occurred in three cases. Direct evidence of fetal lesions of the spinal cord was occasionally present, such as signs of motor axonopathy in two cases analyzed by electrophysiological methods and syringomyelic cavitation at the thoracic level in one case. Even though the sensitivity of the investigations to demonstrate microcopic scars in the spinal cord remains weak, the presence of polymicrogyric rearrangements in the perisylvian cortex, known to proceed from a transient ischemic process occurring in the carotid territory during mid-gestation, strongly suggests that a similar mechanism occurred in the spinal cord. In fact, the foot deformity cannot be viewed as the consequence of lesions to brain regions that do not control the foot motility in the fetus. Extraneurological lesions such as jejunal atresia, possibly proceeding from localized vascular compromise, were also encountered. In one sibship, one sister was found to have a severe developmental anomaly of one foot, suggesting that genetic factors may be involved.

Diagnostic value of electromyography and muscle biopsy in arthrogryposis multiplex congenita

Arthrogryposis multiplex congenita (AMC), a clinical syndrome characterized by multiple congenital joint contractures, frequently is caused by lesions in the peripheral nervous system. Two standard tests for the evaluation of the motor unit are nerve conduction studies/electromyography (NCS/EMG) and muscle biopsy. We reviewed the diagnostic value of these two studies in the evaluation of AMC over a 23-year period, analyzing 38 patients with AMC who had NCS/EMG, muscle biopsy, or both. Final diagnoses were classified as neurogenic (8 patients), myopathic (10 patients), "other" (12 patients), or unknown (8 patients). Neither test alone had consistently high sensitivities, positive predictive values, or specificities. However, when NCS/EMG and muscle biopsy were concordant for neurogenic or myopathic findings, they were more accurate than either test alone, especially for neurogenic diseases. Test results were most commonly discordant in patients with "other" or unknown diagnoses. These findings suggest that when the clinical evaluation indicates a specific syndromic, developmental, or exogenous cause, NCS/EMG and muscle biopsy are not helpful and may not need to be performed. When the history, examination, and genetic evaluation are unrevealing, NCS/EMG and muscle biopsy together provide valuable diagnostic information.

Multiple congenital contractures: birth prevalence, etiology, and outcome

OBJECTIVES

We wanted to estimate the birth prevalence of multiple congenital contractures (MCC), determine the cause of the MCC according to the primary level of involvement of the developing motor system, and compare the different groups in terms of inheritance, mortality, and morbidity.

STUDY DESIGN

A retrospective epidemiologic study through the screening of registers, reviews of medical records, and clinical re-examinations was performed in western Sweden to identify all the children with MCC born between 1979 and 1994.

RESULTS

The birth prevalence of MCC on the basis of 68 cases was 1 in 5100 live births. The majority of cases with cerebral involvement (n = 23), spinal involvement (n = 16), or mechanical restriction (n = 3) were sporadic, whereas most cases with neuromuscular (n = 12) or connective tissue involvement (n = 9) were inherited. The cerebral group was more severely affected compared with the other groups in terms of mortality, joint contractures at birth, feeding difficulties during infancy, and independent walking at follow-up. In 8 cases with myopathy, the joint contractures were normalized on follow-up.

CONCLUSION

A search for a specific etiology in each case is important for genetic counseling, prognosis, and therapy because inheritance, mortality, and morbidity differ between the groups.

Asymmetric arthrogryposis multiplex congenita with focal pachygyria

A male infant with predominantly right-sided arthrogryposis multiplex congenita is presented. His posture in the lower extremities was asymmetric, and left thoracic scoliosis was present. This patient also manifested focal pachygyria dominantly affecting the contralateral cerebral hemisphere and hypoplasia of the corpus callosum, brainstem, and cerebellar vermis. Generalized tonic seizures began at 2 months of age, and an electroencephalogram revealed epileptic discharge. Biopsy of the right biceps revealed a nonspecific change. A direct causal relationship between neuronal migration disorders and arthrogryposis multiplex congenita has not been established, but considering the abnormal neuronal migration along the entire neural axis in focal pachygyria, the predominantly right-sided arthrogryposis in this patient was speculated to be closely related to the pachygyria of the frontal and temporal lobes dominantly affected in the left cerebral hemisphere.

The mouse SLIT family: secreted ligands for ROBO expressed in patterns that suggest a role in morphogenesis and axon guidance

The Slit gene encodes a secreted molecule essential for neural development in Drosophila embryos. Here we report the identification of three Slit homologues in the mouse. We demonstrate that the mouse SLIT1 protein can bind ROBO1, a transmembrane receptor implicated in axon guidance. Both whole-mount and section in situ hybridization studies reveal unique and complementary patterns of expression of the three mouse Slit genes and of Robo1, both within the central nervous system and in other developing tissues. The complementary expression patterns of Slit and Robo1 and their in vitro interaction suggest a ligand-receptor relationship. The expression of all three Slit genes in the floor plate suggests that they are likely to share the same functional properties with their Drosophila homologue in midline neural development and axon guidance. The complementary expression of Slit and Robo1 in different subdivisions of the somites suggests their possible function in axon pathfinding and neural crest cell migration. The unique expression pattern in limb and other organs indicates additional potential functions of the Slit gene family.

Lissencephaly associated with congenital hypomyelinating and axonal neuropathy

The authors describe an 11-year-old male with severe mental retardation, hypotonia, and arthrogryposis, with both type I lissencephaly and a congenital peripheral neuropathy, probably hypomyelinating with axonal involvement. To the best of the authors' knowledge, this is the first report involving the co-occurrence of these two developmental disorders. A viral, metabolic, or nutritional insult acting throughout the period of migration and myelination or a contiguous gene linkage are possible explanations for this disorder.

Arthrogryposis multiplex congenita

The common factor causing congenital arthrogryposis is lack of fetal movements. This can result from a large number of disorders. They may be neuropathic, affecting the brain, the spinal cord, or the peripheral nerves; they may be abnormalities of the muscles, such as myasthenia gravis, congenital muscular dystrophies or mitochondrial cytopathies; they may be diseases of the connective tissues; or they may be conditions which limit the space within the uterus; or they may result from defects of the uterine environment. These are discussed in turn. Typical clinical findings are given and it is emphasised that the arthrogryposis is often a manifestation of certain syndromes, some the result of abnormal chromosomes. Although it is not within the scope of this review article to describe these in detail, examples are given. In particular the subgroup of distal arthrogryposes and amyoplasia are considered. The importance of trying to define a cause is especially the need to give reliable genetic advice to the parents and also to establish a prognosis. The diagnosis will often be made by the associated symptoms and signs, and sometimes by tests such as electromyography and muscle biopsy. Although some of the diseases will be fatal early in life, there are many instances when the child will survive into adult life; if due attention is given to the treatment, particularly orthopedic procedures, and to social and educational management. This can only be done realistically if there is a good idea of the natural history of the condition underlying the arthrogryposis.

Dystonia in a patient with deletion of 18p

18p- syndrome from chromosomal deletion of the short arm of chromosome 18 shows a wide range of clinical manifestations. Mental retardation is the most frequent neurological complication; other neurological deficits are more rarely reported. Only one 18p- patient with focal dystonia at the lower limbs has been reported, while there have been no reported cases of generalized dystonia. We report a 27-year-old male with 18p- de novo complete deletion (karyotype 46,XY,18p-) who was affected by severe generalized dystonia, hypokinesia, mental retardation and dysmorphic features. The 18p- syndrome should be added to the list of genetic causes of secondary dystonia. A karyotype analysis should be considered in secondary dystonias, particularly when there are associated dysmorphic features and mental retardation.