Persistent preceding focal neurologic deficits in children with chronic Epstein-Barr virus encephalitis

Epstein-Barr virus encephalitis is a self-limiting disease with few sequelae. Persistence of neurologic deficits prior to and after the acute illness has yet to be described in children. We describe five children with persistent cognitive and focal neurologic deficits due to chronic Epstein-Barr virus encephalitis with various T2-weighted magnetic resonance imaging abnormalities. Clinical features were a 9-year-old boy with aphasia and apraxia, an 11-year-old girl with impulsivity and inappropriate behavior, a 17-year-old boy with deterioration of cognitive skills and judgment, a 5-year-old boy with complex-partial seizures, and a 6-year-old girl with obsessive-compulsive behavior. All patients had elevated serum Epstein-Barr virus titers for acute infection, with cerebrospinal fluid polymerase chain reaction positive for Epstein-Barr virus in four patients. Three children were treated with methylprednisolone with minimal improvement without changes on magnetic resonance imaging. Epstein-Barr virus encephalitis can present with chronic and insidious neurologic symptoms and should be considered in the differential diagnosis of children with acute or chronic neurologic illness of unknown etiology.

The efficacy of divalproex sodium in the prophylactic treatment of children with migraine

OBJECTIVE

To determine the beneficial use of divalproex sodium as a prophylactic treatment for migraine in children.

BACKGROUND

Previous studies for treatment of migraine in adults have shown a greater than 50% reduction in migraine attack frequencies. Few data exist, however, regarding the efficacy and safety of divalproex sodium use in children with migraine.

METHODS

We studied the incidence of headache relief in our patients with migraine aged 16 years and younger treated with divalproex sodium prophylactically at our institution from July 1996 to December 1998 to determine medication dosage used, concomitant headache medications, and possible adverse effects.

RESULTS

A total of 42 patients, ranging in age from 7 to 16 years (mean age, 11.3 years), were treated with divalproex sodium for headache. All had a history of migraine with or without aura. Baseline headache frequency during a minimum 6-month period was one to four headaches per month. Divalproex sodium dosage ranged from 15 mg/kg/day to 45 mg/kg/day. Of the 42 patients, 34 (80.9%) successfully discontinued their abortive medications. After 4 months' treatment, 50% headache reduction was seen in 78.5% of patients, 75% reduction in 14.2% of patients, and 9. 5% of patients became headache-free.

CONCLUSION

These results indicate divalproex sodium to be an effective and well-tolerated treatment for the prophylaxis of migraine in children.

Functional brain imaging in neuropsychiatric disorders of childhood

This review article presents a summary of the current state-of-the-art of functional brain imaging, with a primary focus on childhood neuropsychiatric disorders. Coverage is emphasized for developments that appear to be of current or potential future importance for the child neurologist and related pediatric specialist, and also from the perspective of the developmental neuroscientist. Emphasis is placed on the modalities of single photon emission computed tomography (SPECT), positron emission tomography (PET), and both "conventional" and "functional" magnetic resonance imaging, (MRI) including reference to the major new radiopharmaceutical and magnetic resonance-based imaging agents and techniques. The fundamental physicochemical processes underlying such studies are outlined, with citation of sources of more detailed information for the interested reader. A variety of imaging studies are reviewed for selected groups of childhood neuropsychiatric disorders, designed to illustrate the achievements and future promise of these imaging modalities. Areas of concentration are suggested for future imaging research in the field of childhood behavioral disorders, where these methods seem critical to improved understanding of pathogenetic mechanisms, as well as development of more effective treatment strategies.

Biotin-responsive basal ganglia disease: a novel entity

We describe a novel, biotin-responsive basal ganglia disease in 10 patients. At onset, it appears as a subacute encephalopathy, with confusion, dysarthria and dysphagia with occasional supranuclear facial nerve palsy or external ophthalmoplegia, and progresses to severe cogwheel rigidity, dystonia and quadriparesis. These symptoms disappear within a few days if biotin (5-10 mg/kg/day) is administered, and there are no neurological sequelae. They reappear within 1 month if biotin is discontinued. Patients diagnosed late, or who have had repeated episodes, suffer from residual symptoms such as paraparesis, mild mental retardation or dystonia. The numerous biochemical studies of intermediary metabolism, like the autoimmune and toxicological studies, enzyme assays including biotinidase, carboxylase and lysosomal activities, and bacterial and viral studies were all normal. The aetiology may be related to a defect in the transporter of biotin across the blood-brain barrier. The only consistent radiological abnormality was central necrosis of the head of the caudate bilaterally and complete, or partial, involvement of the putamen on brain MRI. This was present during the initial acute encephalopathy and remained unchanged during follow-up of 3-10 years. Although its aetiology is unknown, it is important to recognize this disease, since its symptoms may be reversed and the progression of its clinical course prevented simply by providing biotin.

Subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE), a neurodegenerative disease caused by a persistent "slow virus infection" with a mutated measles virus, is endemic in much of the developing world. Its incidence will increase in the USA, not only in immigrants, but also because of the 1988-1990 measles epidemic. This report reviews the pathogenesis, clinical and laboratory diagnosis, and future perspectives in treatment and prevention.

Subacute sclerosing panencephalitis: evaluation with CT and MR

PURPOSE

To evaluate the progression of CT and MR changes of the brain in subacute sclerosing panencephalitis (SSPE) as a basis for assessing the effects of different types of therapy.

METHODS

Fifty-two patients with SSPE were examined, 44 with MR imaging and 42 with CT of the brain on one or more occasions. A total of 92 MR and 67 CT studies were performed.

RESULTS

Correlation between the clinical status and the MR findings in admission was poor. Of 20 patients with clinically advanced disease, only 8 had marked MR abnormalities; 6 had normal or almost normal findings on MR examinations. Two of 4 patients with clinically mild disease had advanced MR changes. The progression of the MR findings appeared to follow a constant pattern. The earliest pathologic finding was focal, high-T2-intensity white matter changes; later atrophic changes followed. The atrophy lagged behind the white matter changes and was thus mild when white matter changes were moderate or severe. In the most advanced stage, when the patient was in a neurovegetative state, an almost total loss of white matter had usually taken place. At this stage, the corpus callosum was also thin. Basal ganglia changes, usually involving the putamina, were seen in one third of patients and cortical gray matter changes were seen in one fourth of patients examined with MR imaging. In 2 of 20 patients, MR changes regressed in parallel with clinical improvement following therapy, but in 5 patients clinical improvement was accompanied by progression of MR changes.

CONCLUSION

The progress of MR abnormalities seen in patients with SSPE seems to follow a constant pattern, but the severity of MR changes does not always correlate well with the clinical findings. Caution must therefore be used when evaluating the effects of therapy.

Familial childhood primary lateral sclerosis with associated gaze paresis

Three children from consanguineous parents began losing the ability to walk in late infancy. Despite chronically progressive weakness leading to wheelchair dependence by adolescence and later loss of motor speech production, intellect remained preserved. Examination revealed upper motor neuron findings of pseudobulbar palsy and spastic quadriplegia, without dementia, cerebellar, extrapyramidal or sensory signs. In addition they exhibited a diffuse conjugate saccadic gaze paresis, especially severe on down-gaze. CT and MRI scans of brain and spinal cord, EEGs, visual and brainstem auditory evoked potentials, CSF examinations, enzyme assays for lysosomal storage diseases, blood amino acids and urine organic acids were all normal. Cortical somatosensory evoked potentials were poorly configured in two of the patients, though they had normal central conduction. EMG showed no signs of denervation. Nerve conduction studies showed normal peripheral motor and sensory conduction velocities. Transcranial magnetic stimulation of the brain elicited no motor-evoked potentials. Despite the lack of neuropathological confirmation, the clinical course and neurophysiologic data strongly support the diagnosis of a familial (autosomal recessive) primary lateral sclerosis (PLS).

Ataxia-oculomotor apraxia syndrome

Ataxia-oculomotor apraxia is a distinct entity first comprehensively described in 1988. The features include early childhood onset of ataxia and oculomotor apraxia, mimicking ataxia telangiectasia but without the extraneurologic findings of ataxia telangiectasia. We add to the clinical description of the ataxia-oculomotor apraxia syndrome by reporting eight patients, ages 2 to 15 years, from four families, suggesting autosomal recessive inheritance, with the longest follow-up over 6 years. After initial gait deterioration, all had a nonprogressive course. We have postulated that ataxia-oculomotor apraxia should be established as a separate disease from ataxia telangiectasia or its variants not only by clinical history, examination findings, and course, but primarily by the biologic markers of normal chromosome breakage and radiation sensitivity studies. We found no increased chromosome breakage in the four patients studied and intermediate sensitivity to chronic ionizing radiation of cultured skin fibroblasts on the three patients studied. Family studies revealed an intermediate radiosensitivity from two patients, their asymptomatic parents, and a sister. The lack of chromosome breakage strongly separates ataxia-oculomotor apraxia from ataxia telangiectasia. The radiation sensitivity studies are compatible with two possibilities: (1) symptomatic ataxia telangiectasia heterozygotes, but this would be highly unusual because the degree of clinical involvement in the ataxia-oculomotor apraxia patients is not mild, as would be expected if they were heterozygotes and (2) a separable disease entity, which is the interpretation we favor.

Ataxia-ocular motor apraxia syndrome: an investigation of cellular radiosensitivity of patients and their families

Although ataxia-ocular motor apraxia (AOA) has been described as a disease entity mimicking ataxia telangiectasia (AT), no radiobiological studies have been carried out on cells from patients with AOA to find their possible relationship to AT. In the present study, cultured fibroblasts from three patients with AOA and their asymptomatic relatives (parents and sibs) were, therefore, compared with those from a classical AT homozygote, an AT heterozygote, and four healthy subjects for cell survival after acute and chronic irradiation. While a moderately increased cellular sensitivity (compared to normal) was observed in two AOA patients and most of their relatives, the degree of their radiosensitivity was quite different from that of the AT homozygote after both acute and chronic irradiation. One AOA patient exhibited increased cellular sensitivity similar to that of a classical AT homozygote up to 4% survival level after chronic irradiation but not after acute irradiation. A comparison of peripheral blood lymphocytes from two AOA patients, an AT homozygote, and two normal controls for spontaneous and (acute) radiation induced chromosomal breaks also failed to show any similarity between AOA and AT. These data support the notion that AOA is different from classical AT, and may represent a distinct disease entity controlled by specific gene(s), or compound heterozygotes involving different AT genes promoting the manifestation of AOA characteristics.

Ethylmalonic aciduria: an organic acidemia with CNS involvement and vasculopathy

Five infants from 3 families, one Egyptian, two Yemeni, are described with a progressive encephalopathy, four of whom have been studied in detail. All patients showed vascular lesions of the skin, characterized by waxing and waning petechiae and ecchymoses. Acrocyanosis was present in three patients. All patients showed retinal lesions characterized by tortuous veins. Protracted diarrhea was not a consistent finding, although they had metabolic crisis in association with diarrhea. They did not show failure to thrive. The neurologic symptoms were indicative of a progressive pyramidal tract disease. Three patients died following sudden emergence of severe basal ganglia, putaminal and head of caudate lesions. In one patient the CT changes in brain were suggestive of infarction. The patients who died manifested pulmonary congestion, or wet lung, and respiratory difficulties during the terminal stage of the disease. In all patients before and during the terminal event, mild-to-moderate hematuria, and in two RBC in CSF, was observed. In one patient there was mild hemoperitoneum at the terminal event. The urine organic acids indicated increased excretion of ethylmalonic, methylsuccinic, glutaric, and adipic acids. The patients invariably showed lactic acidosis, but no ketosis, during and in between the acidotic attacks of the disease. The acylcarnitine profile in blood of two patients showed a pronounced increase in C4 and C5 carnitine esters. In three patients, biopsies from petechiae indicated absence of an immune event, showing only fresh hemorrhage. An immunologic study in one patient was normal for the suppressor:cytotoxic lymphocyte ratio and concentration of interleukin-2 receptor during and in between hemorrhagic attacks. The cytochrome c oxidase activity in fibroblasts was normal. The rate of oxidation of glucose, leucine, isoleucine, valine, propionate and butyrate by fibroblasts was normal. The disease is not responsive to treatment with riboflavin, ascorbic acid, vitamin E, glycine, or carnitine. One patient remained stable on prolonged large doses of methylprednisolone. The biochemical defect leading to ethylmalonic aciduria in this disease remains unknown.

Unusual presentations of propionic acidemia

The files of 25 patients with propionic acidemia (PA), followed by the Inborn Errors of Metabolism Service (IEMS) at King Faisal Specialist Hospital and Research Centre (KFSH & RC) from 1990 to 1993, were studied retrospectively. In 14 patients PA presented acutely with acidosis, hyperammonemia and thrombocytopenia, while in 11 patients the presentation of the disease was unusual. In the latter group, two neonates with PA initially appeared as a primarily hyperammonemic metabolic disease. In two other neonates the vomiting was so severe that they were diagnosed as intestinal obstruction in referral hospitals. The presentation in three infants was primarily as an immune disorder. In four infants, PA appeared as an acute or chronic encephalopathy, i.e. as a silent organic acidemia, with few other findings of the disease. The clinical picture of PA includes facial and nipple dysmorphia, severe hypotonia and vomiting. Severe thrombocytopenia is the hallmark of the metabolic crisis. In one patient it was noticed late and caused intracranial hemorrhage, while in three others intracranial bleeding caused death. The prognosis in PA remained grave despite rigorous treatment. Only seven of the 25 PA patients remained to have a normal life-style, while eight patients expired. The diagnosis is readily achieved by urine gas chromatography/mass spectrometry (GC/MS), by tandem mass spectrometry (MS/MS), or by enzyme analysis of fibroblasts. While there may be both examiner- and patient-related reasons for the variations in the presentation of PA, one other reason may be the heterogeneity of the molecular defect in propionyl-CoA carboxylase.

Experience of King Faisal Specialist Hospital and Research Center with Saudi organic acid disorders

The Inborn Errors of Metabolism and Neurology Services of the King Faisal Specialist Hospital and Research Centre (KFSH&RC) and Armed Forces Hospital have received more than 1,500 patients suspected of having an organic acid disorder (OAD) during a period of four years. Of these, 307 patients suspected of having an organic acid disorder (OAD) during a period of four years. Of these, 307 patients, approximately 20%, had a clearly identifiable disorder. Identified OAD's constituted one-quarter of all patients diagnosed as having various types of inborn errors of metabolism during this period, in these clinical services. Prolonged follow-up was available in the majority of cases, allowing detailed clinical, neuroradiologic and neurophysiologic descriptions. Fifty patients (16%) had rare disorders by standards in the West. Approximately 25% were 'neurologic organic acidurias.' This is a new term we are introducing for OAD's manifesting primarily with neurologic signs, but without appreciable acidosis, hypoglycemia or hyperammonemia. In this special issue, we present the KFSH&RC experience with the rare disorders as individual articles. We estimate the frequency of OAD's in Saudi Arabia as 1/740 births. The increased frequency of OAD's in Saudi Arabia is probably due to increased consanguinity, since most OAD's occurred in excess in certain tribes; and due to increased surveillance and testing by our group. Saudi Arabia provides a unique opportunity for research in this area of pediatrics.

A new patient with alpha-ketoglutaric aciduria and progressive extrapyramidal tract disease

A 4.5-year-old boy with chronic progressive encephalopathy is described. The clinical presentation initially included seizures and hypotonia which later evolved into severe extrapyramidal disease and dementia. The gas chromatography/mass spectrometry (GC/MS) analysis of urine indicated that alpha-ketoglutarate was increased 210 times and aconitic acid 80 times. No disturbance of acid/base balance, lactic acid or ammonia metabolism accompanied this clinical picture. The fibroblasts contained 29% of normal alpha-ketoglutarate dehydrogenase activity, while the activity of another mitochondrial marker enzyme, glutamate dehydrogenase, was normal. The neuroimaging studies revealed bilateral striatal necrosis. The clinical and biochemical findings were almost identical to two previously reported patients. Experience with this patient emphasizes the need for detailed organic acid biochemical investigation in any progressive encephalopathy and that extrapyramidal tract signs should evoke the possibility of alpha-ketoglutaric aciduria, among other 'neurologic organic acidemias'.

Movement disorders in childhood organic acidurias. Clinical, neuroimaging, and biochemical correlations

Over the last 5 years the Pediatric Neurology service at King Faisal Specialist Hospital and Research Centre (KFSH&RC) has seen 131 infants and children with movement disorders. Forty-nine (37%) had identifiable biochemical defects, 25 of which were organic acidemias. Nineteen of 29 patients with dystonia had organic acidemias, primarily glutaric aciduria type 1 (7 patients), bilateral striatal necrosis (4 patients), and 3-methyl glutaconic aciduria (3 patients). All patients with parkinsonian rigidity (n = 11) had organic acidemias; again, the greatest number accounted for by glutaric aciduria type 1 (7 patients), who had both parkinsonian rigidity combined with dystonia. Myoclonus occurred in only 1 of 25 and chorea in 7 of 25 patients with organic acidemias. At the least all patients had bilateral lesions of putamen and head of caudate, seen best in MRI brain scans as increased T2 signal intensities with normal volume, and later with volume loss.

Neurophysiologic correlates of organic acidemias: a survey of 107 patients

The files of 107 patients with 19 different types of organic acidemia were reviewed retrospectively. Approximately 50% of the patients had abnormal electroencephalogram (EEG) at the time of initial study. In patients who had serial studies, the EEG deteriorated in 38% and improved in 15%. The predominant EEG abnormality encountered was slowing of the background activity in various degrees. Focal or generalized paroxysmal activity occurring in conjunction with slow background activity indicated a poor prognosis. Brainstem auditory evoked potentials (BAEP), visual evoked potentials (VEP), and somatosensory evoked potentials (SEP) were analyzed. The VEP was abnormal in 44%, BAEP in 39%, and SEP in 29% of the patients. Given the magnitude and frequency by which neurophysiological abnormalities occur in organic acidemias, neurophysiology testing provides complementary functional information and has an important place in the clinical work-up of these diseases.

4-Hydroxybutyric aciduria

The clinical findings in six patients from three families with 4-hydroxybutyric aciduria are described. The onset of disease was in early infancy in all cases. All infants presented with severe global delay and severe hypotonia, and all patients had seizure disorder. Eye findings included optic atrophy in two patients, and retinitis pigmentosa in one. Three patients had choreoathetosis, two had myoclonus and one had severe dystonia. The urine 4-hydroxybutyric acid was 300-1000 times that of normal, and other organic acids related to its further metabolism or to its inhibitory effect on beta-oxidation were also increased. The administration of vigabatrine rapidly reduced the excretion of 4-hydroxybutyric acid promptly, and in the long-term its excretion could be kept at 80-200 times that of normal. However, the clinical course of the disease improved in only two, remained the same in two, and worsened in the remaining two patients.

3-Methylglutaconic aciduria: ten new cases with a possible new phenotype

3-Methylglutaconic aciduria is an organic aciduria with diverse phenotypic presentations. In more than half of the cases it is a 'neurologic or silent organic aciduria', and, except for one subtype, the biochemical defect is unknown. This report describes 10 new patients. Four of them presented with early global neurologic involvement and arrested development. They rapidly became demented, developed myoclonus or tonic-clonic seizures, spastic quadriplegia, deafness and blindness, and died. Three had acidosis and hypoglycemia neonatally; later, myoclonus and deafness, and eventually severe mental retardation and spastic quadriplegia developed. One patient died. In three children who presented with sudden onset of extrapyramidal tract symptoms, with or without optic atrophy, the clinical presentation was significantly different from that described either for 'unspecified' type or for Costeff syndrome. All three patients showed clinical improvement soon after treatment with coenzyme Q.

The clinical spectrum of biotin-treatable encephalopathies in Saudi Arabia

Ten patients with biotin-dependent, chronic progressive encephalopathies were studied retrospectively. In four patients, the underlying disease was either total or partial deficiency of biotinidase. In one patient, the disease was caused by a lack of holocarboxylase synthetase activity. Four patients presented with Leigh encephalopathy. However, a biochemical defect could not always be confirmed. All patients required the administration of large doses of biotin to maintain normal neurologic function.

3-Ketothiolase deficiency: a review and four new patients with neurologic symptoms

3-Ketothiolase deficiency (3KTD) manifests with intermittent acidosis and is due to deficiency of mitochondrial 2-methylacetoacetate thiolase. Only 22 patients have been previously reported. Although its variable clinical presentation is recognized, the associated neurological findings have not been detailed. We report four new patients all with significant neurological symptoms. Three patients were examined with MRI of the brain which showed increased T2 intensity within the posterior lateral part of the putamen bilaterally. In two the MRI was otherwise normal; in one delayed myelination was also seen. These MRI putaminal findings may be typical enough to suggest the diagnosis of 3KTD. Two of the three had abnormal EEGs; one had an abnormal VEP. 3KTD can thus occur as an organic acidemia associated with encephalopathy.

Sanfilippo type D presenting with acquired language disorder but without features of mucopolysaccharidosis

A 7-year-old girl presented with a language disorder reminiscent of verbal auditory agnosia. Later, she proved to have defective N-acetylglucosamine-6-sulfate sulfatase, the enzyme deficient in Sanfilippo D syndrome. She did not show clinical features of mucopolysaccharidosis. The language disorder had a fluctuating course, which eventually evolved into a progressive dementing encephalopathy.

A preliminary study of the relationship between central auditory processing disorder and attention deficit disorder

Fifteen boys aged six to ten who met the criteria for attention deficit disorder (ADD) were compared with ten boys who did not have ADD in a double-blind, placebo-controlled, single-crossover study of methylphenidate. To assess the degree of overlap between ADD and central auditory processing disorder (CAPD), all subjects were assessed on parent and teacher behavior rating scales, as well as a battery of CAPD tests at baseline and after three and six weeks of treatment. Twelve of the 15 subjects with ADD and none of the subjects without ADD met the criteria for CAPD. The subjects with ADD also responded to stimulant treatment on the measures of both ADD and CAPD. The overlap in the symptomatology of these disorders, the finding that the criteria for both disorders were met in 12 of 15 cases and the sensitivity of both ADD and CAPD measures to treatment with methylphenidate suggest that ADD and CAPD are closely related disorders. The implications of these results are three-fold. First, sustained attention is a critical feature of performance on CAPD tests and the current diagnostic criteria for CAPD make a clinical separation of the two disorders problematic. Second, stimulants appear to be a useful treatment for the symptoms of both ADD and CAPD. Third, CAPD tests may be a useful measure of ADD symptomatology and response to stimulants.

Chorea as a presentation of herpes simplex encephalitis relapse

Three infants, ages 3 months to 3 years, presented with chorea as the initial manifestation of herpes simplex encephalitis (HSE) relapse. Patient 2, treated with repeated 10 day courses of 30 mg/kg/day of acyclovir, had no clear improvement in neurological status. Patient 1, treated with a repeated 10-day course, improved only to have another HSE relapse 4 years later. Patient 3 clearly improved soon after a 3-week course of acyclovir at conventional dosages. A fourth patient (Patient 4) who relapsed with chorea after what was thought to be HSE, and who did not respond to repeated acyclovir treatment, was negative for herpes simplex virus indicators on brain biopsy and DNA testing. We recommend treating all patients suffering from HSE with a minimum 3-week course of acyclovir at 30-35 mg/kg/day in 3 divided doses.

Heterogeneity of carboxypeptidase activity in infantile-onset galactosialidosis

The clinical presentation and laboratory findings in seven patients with neonatal/infantile-onset galactosialidosis are presented. We detected no carboxypeptidase activity in two of these patients, while an enzyme with different apparent Km, or both Km and Vm, were found in five others. We could not establish a correlation between the biochemical characteristics of carboxypeptidase and the age of onset, progression, or other clinical features of galactosialidosis.

Treatment of inherited neurometabolic diseases: the future

The past 10 years' experience with bone marrow transplantation from normal, immunologically compatible donors indicates its possible use in various neurometabolic diseases, particularly in a patient who has not suffered irreparable brain damage. This experience may be a prelude to treatment by somatic gene therapy. This can be applied as an autologous bone marrow transplant, grafting the patient's own stem cells inserted with the normal gene. Although somatic gene therapy will be relatively easy for tissues with dividing cells, its application to target tissues with little or no cell division may pose difficulties. Meanwhile, techniques for the preservation, culture, and grafting of fetal neurons in humans have been developed and have been used in the treatment of Parkinson's disease. These procedures could readily be transferred to the treatment of other neurodegenerative diseases that cause significant morbidity, but ethical, legal, and religious considerations must be taken into account. All these efforts promise novel and improved management of inborn neurometabolic errors.

Riyadh chromosome breakage syndrome: mental retardation with depigmentation of the skin and hair

A 20-month-old infant with "silvery-blond" hair color, widespread confettilike depigmentation of the skin, and mental retardation was found to have, in lymphocytes and fibroblast cultures, increased spontaneous chromosome breaks and breaks induced by both mitomycin and gamma-irradiation. The sister chromatid exchange frequency was normal. This child probably represents a new chromosome breakage syndrome.

Response of 6-pyruvoyl-tetrahydropterin synthase deficiency to tetrahydrobiopterin

We have given tetrahydrobiopterin (BH4) in doses ranging from 2.5 to 20 mg/kg/day, each for a duration of 5 days to three patients with 6-pyruvoyltetrahydropterin synthase deficiency. As small a dose as 2.5 mg/kg/day BH4 reduced the blood phenylalanine to normal levels. However, the required dose of BH4 to reduce neopterin and to increase urine biopterin was 5 to 10 mg/kg/day, while 20 mg/kg/day was required for biopterin to appear in cerebrospinal fluid. The results suggest that BH4 effectively reduces endogenous neopterin synthesis. The dose of BH4 needed to normalize liver phenylalanine hydroxylase is one eighth to one fourth that required for normal neurotransmitter metabolism in the central nervous system.

GM1 gangliosidosis type 2 in two siblings

A sister and brother, now aged 7 and 9 years, presented with developmental arrest, gait disturbance, dementia, and a progressive myoclonic epilepsy syndrome with hyperacusis in the second year of life. Then, spastic quadriparesis led to a decerebrate state. In the absence of macular or retinal degeneration, organomegaly, and somatic-facial features suggesting mucopolysaccharidosis, the presence of hyperacusis together with sea-blue histiocytes in bone marrow biopsies and deficient beta-galactosidase activity but normal glucosidase, hexosaminidase, and neuraminidase activity on lysosomal enzyme assays constitutes the clinical-pathologic-biochemical profile of GM1 gangliosidosis type 2. This is a rare, late infantile onset, progressive gray-matter disease in which beta-galactosidase deficiency is largely localized to the brain, though it can be demonstrated in leukocytes and cultured skin fibroblasts. It must be distinguished from the Jansky-Bielschowsky presentation of neuronal ceroid lipofuscinosis, mitochondrial encephalopathy, lactic acidosis, strokelike episodes (MELAS) and myoclonic epilepsy with ragged-red fibers (MERRF) syndromes, atypical presentations of GM2 gangliosidoses (Tay-Sachs and Sandhoff's diseases), primary sialidosis (neuraminidase deficiency), galactosialidosis, and Alpers' disease.

Coincident neuraminidase and aspartoacylase deficiency associated with chromosome 9Q paracentric inversion in a Saudi family

A large, consanguineous Saudi family with three members with sialidosis type 1 and five members with infantile central nervous system spongy degeneration of the brain (ICNSSD, or Canavan-Bertrand-van Bogaert disease) is described. The patients with sialidosis had normal aspartoacylase activity, while neuraminidase activity in the patients with ICNSSD was reduced. All patients had normal carboxypeptidase activity in their fibroblasts. In an additional member there was photic-induced epilepsy, but he had normal enzymes. Two of the patients and one normal brother, but not the parents, had pericentric inversion of chromosome 9q. We postulate that an unidentified gene function is responsible for varied expression of these neurodegenerative diseases in this family.

Neurometabolic diseases at a national referral center: five years experience at the King Faisal Specialist Hospital and Research Centre

Of 910 children under the age of 12 years referred to the national center, we were able to assign an etiology to 473 (52%). This group consisted of lysosomal storage diseases (32%), amino acid disorders (14%), organic acid disorders (16%), various chromosome abnormalities and syndromes with dysmorphia or brain dysgenesis (26%), and various other metabolic diseases (12%). While such amino acidemias as branched-chain amino acidemia (MSUD) in classic and intermediate forms (44%) and hyperphenylalaninemia (PKU) due to 6-pyruvoyltetrahydropterin synthase deficiency (6PTSD) (19%) were common, classic PKU was rare (16%). Methylmalonic acidemia (31%), 3-hydroxy-3-methylglutaryl-coenzyme A lyase deficiency (16%), and propionic acidemia (12%) were encountered more frequently than other types of organic acidemias. When compared to the number of referred Down's syndrome patients, the results suggested the birth of at least one infant with neurometabolic disease per 50 births. Five tribes of Saudi Arabia constituted 26% of the diagnosable neurometabolic diseases. Diseases such as MSUD, 6 PTSD, Sanfilippo syndrome type B, methylmalonic acidemia, homocystinuria, GM2 gangliosidosis Sandhoff variant, infantile central nervous system spongy degeneration (Canavan disease), and neuraminidase deficiency showed definite tribal occurrence. In addition, 32% to 42% of the definitely diagnosed, and 25% to 87% of patients with probable neurometabolic disease but without a definable etiology, had more than one sibling affected. It is concluded that the many rare autosomal diseases of Saudi Arabia are due to "founder effect" created by marriages occurring within tribal and extended family boundaries.

Congenital muscular dystrophy with abnormal radiographic myelin pattern

We report 11 children with a homogeneous clinical syndrome affecting both sexes, characterized by weakness at birth, slowly improving course, weakness of all muscle groups, arreflexia, elevated blood creatine kinase, normal nerve conduction velocity, dystrophic changes on muscle biopsy, and diffuse periventricular cortical white-matter abnormalities with sparing of corpus callosum, internal capsule, and brain stem. We compare them to 48 other previously reported similar cases and designate them as altered myelin radiographic pattern congenital muscular dystrophy (CMD), which is the same as occidental CMD. We compare them to the other presently accepted phenotypes: progressive Fukuyama CMD, Walker-Warburg or cerebral-ocular CMD, and Santavuori or muscle-eye-brain CMD. We suggest that the different phenotypes are alleles of the same gene, which regulates or expresses a structural protein required for muscle integrity, myelination, and formation of the cortex. Such phenotypic diversity has been established for mutations of Xp21 in X-linked muscular dystrophies.

Saudi variant of multiple sulfatase deficiency

We describe eight patients with multiple sulfatase deficiency (MSD, or Austin's disease) who differ phenotypically from classic neonatal-, childhood-, or juvenile-onset MSD. The age of onset was in childhood. The patients presented with somatic and facial features of mucopolysaccharidosis reminiscent of Maroteaux-Lamy and Morquio syndromes. They differed from classic MSD by the presence of corneal cloudiness, macrocephaly, severe dysostosis multiplex, and gibbus and the absence of ichthyosis, retinal degeneration, severe deafness, severe mental retardation, and dementia. The main neurologic presentation was cervical cord compression due to axis abnormalities. Despite neuroradiologic evidence of white-matter changes, neurologic presentation was not like metachromatic leukodystrophy. The sulfatase deficiencies were more marked than in the classic juvenile form of MSD, but less marked than in the classic childhood-onset form of MSD. Steroid sulfatase activity was spared except in one patient. This Saudi variant of MSD accounts for 5% of all lysosomal storage diseases in the Cell Repository Registry of our Inborn Errors of Metabolism Laboratory.

Biochemical heterogeneity of infantile central nervous system spongy degeneration

Aspartoacylase, the enzyme whose activity is deficient in infantile central nervous system spongy degeneration (Canavan-Van Bogaert-Bertrand disease), is detected as an approximately 59-kD protein in the Sephadex G-200 filtration of normal fibroblast extracts. The enzyme activity in homogenates of fibroblasts is protected by leupeptin, a protease inhibitor. In the absence of leupeptin, 90% of aspartoacylase activity is lost. In some patients with infantile spongy degeneration, no activity (less than 2%) can be detected. In some other patients with residual activity in fibroblasts, two separate peaks of enzyme are eluted with molecular weight corresponding to approximately 59 and 19 kD. Aspartoacylase activity in this latter group is protected to the same extent by the presence of leupeptin. However, the elution of two peaks is independent of the presence of leupeptin. This study indicates biochemical heterogeneity in the pathogenesis of infantile spongy degeneration.

Werdnig Hoffman's disease (spinal muscular atrophy type I): A clinical study of 25 Saudi nationals in Al-Khobar

We describe the clinical features of 25 cases of Werdnig Hoffman's disease (spinal muscular atrophy (SMA) type I) seen propectively over a two-year period at the King Fahd Hospital of the University (KFHU), Al-Khobar. The hospital incidence rate was 1.93 per 1,000 live births (95% confidence limits, 0.80-3.06/1,000). The estimated prevalence rate for the community was 0.92/10,000 with 0.59-1.25 per 10,000 children as its 95% confidence limits. The male to female ratio was 2:3. Reduced fetal movements were reported by six mothers; 8 children (32%) had symptoms at birth, and 24 (96%) had symptoms by the time they were six months old. Other features apart from hypotonia, muscle weakness, and absent deep tendon reflexes included head lag with inability to achive head control at six months (88%), respiratory problems consisting of difficulty with breathing or frequent chest infections (44%), and difficulty with feeding (40%). Wasting with fisciculations of the tongue was seen in 64%. Death occurred within six months of presentation in 75% of the cases. The parents were consanguineous in 64% of the cases. This high consanguinity rate was probably the major cause for the high population prevalence rate.

Organic acidurias: a review. Part 2

Laboratory findings are an essential part of the diagnostic approach to organic acidemias. In most organic acidemias, metabolism of glucose, ketone bodies, and ammonia is deranged primarily or secondarily, in addition to derangement of the acid-base balance. Hypoglycemia, lactic and/or ketoacidosis, and hyperammonemia of varying severity accompany the overt or compensated acidosis. In most instances, a definite diagnosis will be achieved by gas chromatography/mass spectrometry (GC/MS) studies of the urine. We detail the pattern of excreted organic acids in the major disorders. When the diagnosis reached by clinical and laboratory assessments is not conclusive, it must be supported by loading tests. We list the available methods of demonstrating the putative enzyme deficiency in the patient's cells and tissues. The majority of organic acidemias may be treated by limiting the source of or removing the toxic intermediary metabolite. We provide lists of available diets, supplements, and medications. In some instances, residual defective enzyme activity may be stimulated. We describe symptomatic management of the disturbed acid-base and electrolyte balance.

Cytogenetic investigations in three cell types of a Saudi family with ataxia telangiectasia

Chromosomal analyses were performed on lymphocytes, fibroblasts and lymphoblastoid cell lines derived from a Saudi family with ataxia telangiectasia (AT). The three siblings of a consanguineous marriage were all affected. The lymphocytes of the AT homozygotes (probands) showed an increase of 2- to 6-fold and 4- to 8-fold respectively, in the frequency of spontaneous and X-ray-induced chromosomal aberrations compared with controls, while the parents (obligate heterozygotes) of the patients showed no notable difference. The unirradiated lymphocytes from the oldest AT sibling, an 11-year-old boy (AT1), showed specific rearrangements involving chromosomes 7 and 14 [t(7;14)(q35;q12)] and 12 and 14 [t(12;14)(q23;q12)] in two different clones. The most severely affected sibling was a 9-year-old girl (AT2) who presented with a clone showing a novel rearrangement involving chromosomes 14 and 17, namely: del(14) (q31q32) and dup(17)(q21-q24). The lymphocytes from the third sibling, a 2-year-old boy (AT3), showed a t(2;14)(p24;q12). In addition, an inv(14)(q12q32) was observed in all three AT patients, while inv(7)(p14q35) was found only in patients 2 and 3. The lymphocytes from the AT parents and controls showed normal karyotypes. The breakpoints involving chromosomes 2, 12 and 17, observed in our studies, have rarely been reported in other series of AT patients. No non-random chromosomal rearrangements were observed either in the skin fibroblasts or in the lymphoblastoid cell lines derived from the AT patients, although all cell lines showed an increase in both spontaneous and radiation-induced chromosomal breaks per cell. The present study constitutes the first report on a cytogenetic analysis of a Saudi family with three AT siblings.

Organic acidurias: a review. Part 1

Organic acidemias are disorders of intermediary metabolism that lead to accumulation of organic acids in biologic fluids, disturb acid-base balance, and derange intracellular biochemical pathways. Their clinical presentation reflects the resultant systemic disease and progressive encephalopathy. While in some organic acidemias, disturbed acid-base metabolism is the predominant presenting feature, in others it is less prominent or even absent. The etiologies of the more than 50 different phenotypes include impaired metabolism of branched-chain amino acids, vitamins, glucose, lipids, glutathione, and gamma-aminobutyric acid and defects of oxidative phosphorylation. Most organic acidemias present with neurologic manifestations, which include acutely or subacutely progressive encephalopathy that involves different parts of the nervous system. The age of presentation and the associated systemic, hematologic, and immune findings provide additional guidelines for differential diagnosis. We summarize major organic acidemias, while emphasizing their usual and unusual neurologic presentations.

Infantile CNS spongy degeneration--14 cases: clinical update

We studied 14 Arab infants with infantile spongy degeneration, 13 of whom were products of consanguineous marriages. They presented in infancy with macrocephaly, poor visual behavior or blindness, and axial hypotonia with appendicular spasticity. Brain CT and MRI showed diffuse symmetric leukoencephalopathy, even before neurologic symptoms. There were relatively normal EEGs. The visual evoked responses (P100) were either absent or delayed early in the course. The brainstem auditory evoked responses showed milder abnormalities, with loss of later components before the earlier ones. Deficient aspartoacylase activity in cultured fibroblasts or brain biopsy confirmed the diagnosis in all patients.

Phenotypic heterogeneity of spinal muscular atrophy mapping to chromosome 5q11.2-13.3 (SMA 5q)

We made phenotypic analysis of 14 families with spinal muscular atrophy (SMA) linking to chromosome 5q11.2-13.3 (SMA 5q), and 2 that may not map to this locus, to assess clinical symptoms among SMA families known to result from mutation at the identical gene/locus. Although the current number of families is still small, the correlation of clinical phenotype and molecular genotype supports 2 observations. First, SMA mutations at the 5q locus present with a broad continuum of clinical abnormalities, and 2nd, the single clearly unlinked family presents with an unusual phenotype characterized by relatively late onset and early death. Thus, there are as yet no unambiguous cases of typical SMA families that are clearly unlinked to the locus at 5q-ie, no clear cases of nonallelic heterogeneity. Analysis of SMA 5q families supports the view that, with certain exceptions, there is little phenotypic intrafamilial variability. When families were ranked by severity of disease there was a strong correlation with age of onset. Onset within the 1st few months was associated with early death, but not in all cases. With rare exception, onset after 1 year of age was associated with less severe disease and greater longevity.

Aspartoacylase deficiency and Canavan disease in Saudi Arabia

We found defective aspartoacylase activity in fibroblasts cultured from 12 patients with leukodystrophy clinically diagnosed as spongy degeneration of the brain (Canavan disease), three confirmed by brain biopsy. The activity of aspartoacylase ranged between 1 and 13% of two groups of control individuals, normals, and those with other leukodystrophies. The present report confirms the study of Matalon et al. [1988] in a totally different ethnic group and provides independent verification that aspartoacylase activity is the first documented specific biochemical marker in Canavan disease and plays an important role in pathogenesis. Considering that only some 75 cases had been reported up to 1982, our group of 12, accumulated within 3 years, is inordinately large and suggests that Saudi Arabia provides a promising venue in which to study the biochemical and molecular genetics of Canavan disease.

A pilot controlled study of the use of imipramine to reduce myotonia

It has been hypothesized that myotonic dystrophy is caused by a generalized disorder of membrane aminergic and petidergic receptors. A single uncontrolled study has suggested that the affective symptomatology and muscular disability of this disorder might be improved by tricyclic antidepressant treatment. In the present study, 12 adult patients with myotonic dystrophy (age range 18-55 yr) were treated with imipramine and placebo in a double-blind crossover paradigm. Both grip and percussion myotonia were significantly improved by imipramine treatment independent of change in depressive symptomatology. Serum drug levels revealed nonlinear elimination kinetics for imipramine in this patient population.

Rett syndrome: review and discussion of current diagnostic criteria

Rett syndrome is a mental retardation syndrome that occurs only in females and consists of normal pre-, peri-, and neonatal growth and development. It is followed by rapid neurobehavioral deterioration in late infancy or early childhood, a developmental arrest, plateauing, and then either a course of retarded development or continued deterioration. The period of rapid neuro-behavioral deterioration manifests as a partial autistic syndrome, with loss of production and comprehension of language, hyperactivity, hyperventilation, hand-wringing, and ataxic gait. Current diagnostic criteria are discussed and suggestions for further research are presented.

Pure word deafness (acquired verbal auditory agnosia) in an Arabic speaking patient

A 38-year-old, right-handed Arabic-speaking male developed pure word deafness three days after myocardial infarction. He could recognize Arabic music and instruments but not words of songs; a radio broadcast from the Koran, but not the individual words; a male as opposed to female voice; Arabic and non-Arabic languages; and whether sentences were questions, exclamations, or imperatives. He discerned whether the speaker was emotionally neutral, happy, angry or sad. Contextual cues and reducing the rate of speaking aided verbal comprehension. Pure tone threshhold audiometry revealed mild bilateral sensorineural loss up to 2000 Hz and a moderate high frequency loss. Brainstem auditory evoked potentials were normal, cortical auditory evoked potentials abnormal. CT scan revealed bilateral infarcts subcortically just posterior to the left superior temporal gyrus and the right posterior superior and midtemporal regions. Neurolinguistic tests indicated that the deficit is prephonemic and not due to impairment of linguistic discrimination.