Familial infantile myasthenia.

Familial infantile myasthenia is a rare type of myasthenia that usually occurs in connection with respiratory depression. The condition is characterized by (1) absence of myasthenia in the mother, (2) occurrence of a similar disorder among siblings, (3) respiratory depression at birth, (4) episodic weakness and apnea during the first two years of life, and (5) improvement with age. Since the condition responds to anticholinesterase medication, early diagnosis is important. Familial infantile myasthenia is a potential cause of sudden infant death and should be considered in infants with unexplained respiratory distress.

Familial and acquired paroxysmal dyskinesias. A proposed classification with delineation of clinical features.

On a clinical basis the paroxysmal dyskinesias can be classified into two distinct categories--familial and acquired. The former begins in childhood and the dyskinesia may or may not be induced by sudden movements (kinesigenic or nonkinesigenic forms). In the familial kinesigenic form, the movements are brief, usually occur daily, and respond readily to anticonvulsants. This form has an autosomal dominant or recessive mode of inheritance. In the familial nonkinesigenic form, the movements are of longer duration, occur less frequently, and rarely respond to anticonvulsants. This form has a clear autosomal dominant mode of inheritance. The etiology is obscure. The acquired form of paroxysmal dyskinesia has a later onset and is an expression of an underlying neurological or metabolic disease. Some cases of acquired paroxysmal dyskinesia are manifestations of unusual forms of epilepsy. In these cases the differential diagnosis may be extremely difficult and must be based on EEG findings during an ictal episode.

EEG recognition of Aicardi's syndrome.

Thirty-two EEGs from six cases of Aicardi's syndrome were reviewed. A characteristic EEG pattern was found in all cases. This consists of multifocal epileptiform abnormalities occurring on a burst-suppression pattern showing complete asynchrony between the two hemispheres. This pattern has been described so far only in Aicardi's syndrome. These characteristic EEG features are more readily found early in the course of the disease and occur less frequently six months after from the onset of symptoms, at which time they are often replaced by multiple epileptic foci on a severely disorganized background. The EEG sleep pattern was profoundly altered in all stages of the disease. The EEG is considered a helpful tool in the diagnosis of Aicardi's syndrome.

Hypomelanosis of Ito (incontinentia pigmenti achromians)--a clinicopathologic study: macrocephaly and gray matter heterotopias.

We studied a boy with macrocephaly, hypotonia, pigmentary retinopathy, unilateral whorled hypopigmented skin lesions, and seizures. Skin biopsy confirmed the clinical diagnosis of hypomelanosis of Ito. Postmortem examination at age 22 months revealed a severe neuronal migrational defect that altered the cerebral cortex architecture of white matter. There were many gray matter heterotopias characterized by altered neurons and giant cells. Electronmicroscopy revealed the astrocytic nature of the giant cells. Embryologic migration of both melanoblasts from neural crest and cortical neurons occurs in the second trimester, suggesting a common mechanism for the developmental pathology of skin and brain.

Reenactment of the triggering situation for the diagnosis of epilepsy.

When a fixed set of ambient circumstances is associated with convulsive or nonconvulsive paroxysmal attacks, reenactment of the situation should be considered as a possible shortcut for reaching a diagnosis. Reenactment determined the diagnosis in 30 of 32 patients with paroxysmal disorders. The referral diagnosis was correct in only 13 of the 32 patients. To be appropriately executed, the reenactment should entail polygraphic recording of at least EEG, ECG, and respiration. Vertex electrodes should be included to avoid overlooking of cortical electrodecremental event. If unsuccessful at the first attempt, reenactment should be repeated.

Clinical and extraneural histologic diagnosis of neuronal ceroidlipofuscinosis.

Neuronal ceroid-lipofuscinosis is manifested by visual and intellectual deterioration and seizures. Autofluorescent lipopigments are found in neural and many nonneural tissues, with characteristic staining and ultrastructural properties. Presumptive diagnosis can usually be made on the basis of history, physical examination, and electrodiagnostic tests, but in the absence of a specific biochemical defect, histologic confirmation is essential. A 6-year-old boy with the clinical appearance of the juvenile form of the disease had sea-blue histiocytes in the bone marrow, and curvilinear profiles in ultrastructural inclusions in skin biopsy tissue, cultured skin fibroblasts, and bone marrow cells.

The Dubowitz syndrome: further observations.

An autosomal recessive disorder characterized by intrauterine growth retardation, postnatal retardation, microcephaly, sparse hair, toe syndactyly, and characteristic facial appearance is now recognized as the Dubowitz syndrome. Five addition additional cases of the Dubowitz syndrome are reported, including 2 with documented vascular abnormalities.

La Crosse and other forms of California encephalitis.

The California serogroup viruses are mosquito viruses that cause human infections on five continents. They are maintained and amplified in nature by a wide variety of mosquito vectors and mammalian hosts; they thrive in a remarkably wide variety of microclimates (eg, tropical, coastal temperate marshland, lowland river valleys, alpine valleys and highlands, high boreal deserts, and arctic steppes). In 1993, California serogroup viruses caused 71% of all cases of arboviral illness in the United States, principally La Crosse encephalitis. The 30 to 180 annual cases of La Crosse encephalitis represent 8% to 30% of all cases of encephalitis, rendering this illness the most common and important endemic mosquito-borne illness in the USA. Subclinical or mild infections are much more common. Methods and results acquired from intense study of California serogroup viruses have been applied, with benefit, to the study of the ecology and pathogenesis of many more serious human arboviral illnesses. The evolutionary potential of viruses, with particular reference to the development of more virulent strains, has been studied more closely in the California serogroup viruses than in almost any other agent of human disease.

Phenytoin-induced thrombocytopenia.

A 15-year-old boy developed thrombocytopenia and purpura two weeks after starting phenytoin therapy. The blood phenytoin level was in the toxic range. There was an increase in immature neutrophils but no abnormalities were present in other cell lines. Recovery was complete after drug therapy was discontinued. Thrombocytopenia is a rare isolated complication of phenytoin therapy. The probable autoimmune etiology distinguishes this syndrome from other phenytoin-induced blood dyscrasias.

Acquired paroxysmal movement disorders.

Acquired paroxysmal movement disorders are reported less frequently than the familial forms of paroxysmal dyskinesias. Three children, with the acquired form of the disorder which followed an early childhood encephalopathic event, are described. Three similarly affected children have been reported previously. Movement disorders developing after perinatal encephalopathy appear to be a distinct entity. Patients with this condition demonstrated clinical improvement following the initiation of antiepileptic medications.

Osmiophilic deposits in cytosomes in Hallervorden-Spatz syndrome.

A young child with Hallervorden-Spatz syndrome is presented. She was well until 8 years of age when she lost interest in activities and her school performance declined. At age 11 years, she began having episodes of blepharospasm, accompanied by bilateral ptosis and occasional episodes of oculogyric crisis. By age 12 years, her motor coordination had declined and she began to exhibit evidence of dementia, dystonia, dysarthria, and tremor. Motor incoordination, dystonia, and tremor progressed until the patient was wheel-chair-bound. Multiple tests were performed, including metabolic studies, magnetic resonance imaging, bone marrow biopsy, and electron microscopy of the buffy coat. Both bone marrow and buffy coat revealed inclusions in the cytosomes which were granular and osmiophilic. To our knowledge, this is the third case report of inclusion bodies found in patients with manifestations of Hallervorden-Spatz syndrome. These findings suggest that obtaining a buffy coat and bone marrow biopsy may aid in the diagnosis of Hallervorden-Spatz syndrome and ultimately provide information regarding etiology.

Optic glioma associated with Beckwith-Wiedemann syndrome.

A 6-year-old boy with decreased vision was found to have Beckwith-Wiedemann syndrome with an associated glioma involving the intracranial optic nerves, chiasm, and optic tracts. The association of this syndrome with visceral and central nervous system neoplasms is discussed.

Infantile olivopontocerebellar atrophy with spinal muscular atrophy (infantile OPCA + SMA).

We report three siblings (two boys and girl) with familial (autosomal recessive) infantile olivopontocerebellar atrophy (OPCA) associated with lower motoneuron involvement. Brain autopsy findings in two of the children revealed a multisystem degeneration characterized by marked hypoplasia of phylogenetically new parts of the brain stem (basis pontis and inferior olivary nuclei) associated with hypoplasia of the neocerebellum, both cerebellar and cerebral peduncle. All three infants died before six months of age. The clinical features are characterized by severe hypotonia, areflexia, failure to thrive, respiratory insufficiency in all cases, cardiomyopathy and dislocated hips at birth in two of the three siblings. Extensive serum, urinary and leukocyte enzyme assays in the second infant failed to disclose a specific metabolic abnormality. The diagnosis of OPCA was established prior to death by Magnetic Resonance Imaging (MRI) in the youngest infant. Since OPCA represents a heterogeneous group of diseases, correlation of neuropathologic, clinical, genetic and MRI findings at early stages of evolution becomes crucial in the understanding of the nosology of OPCA and its variants.

Lateral cervical meningocele.

Although lateral meningoceles have been described in the thorax, they have not been previously reported in the neck. We describe an infant who was born with a lateral meningocele in the cervical posterior triangle that was felt clinically to be cystic hygroma. Surgical excision was complicated by a cerebral spinal fluid fistula and subsequent meningitis. Problems that this patient presented and potential complications in management are discussed. Although the clinical manifestations of lateral meningoceles and extradural cysts are quite different, there are many anatomic similarities between these entities and other cervical masses that confuse diagnosis and nosology. Their differential diagnosis is reviewed.