The Complex Genetic Landscape of Hereditary Ataxias in Turkey and Implications in Clinical Practice.

BACKGROUND: The genetic and epidemiological features of hereditary ataxias have been reported in several populations; however, Turkey is still unexplored. Due to high consanguinity, recessive ataxias are more common in Turkey than in Western European populations. OBJECTIVE: To identify the prevalence and genetic structure of hereditary ataxias in the Turkish population. METHODS: Our cohort consisted of 1296 index cases and 324 affected family members. Polymerase chain reaction followed by Sanger sequencing or fragment analysis were performed to screen for the trinucleotide repeat expansions in families with a dominant inheritance pattern, as well as in sporadic cases. The expansion in the frataxin (FXN) gene was tested in all autosomal recessive cases and in sporadic cases with a compatible phenotype. Whole-exome sequencing was applied to 251 probands, selected based on the family history, age of onset, and phenotype. RESULTS: Mutations in known ataxia genes were identified in 30% of 1296 probands. Friedreich's ataxia was found to be the most common recessive ataxia in Turkey, followed by autosomal recessive spastic ataxia of Charlevoix-Saguenay. Spinocerebellar ataxia types 2 and 1 were the most common dominant ataxias. Whole-exome sequencing was performed in 251 probands with an approximate diagnostic yield of 50%. Forty-eight novel variants were found in a plethora of genes, suggesting a high heterogeneity. Variants of unknown significance were discussed in light of clinical data. CONCLUSION: With the large sample size recruited across the country, we consider that our results provide an accurate picture of the frequency of hereditary ataxias in Turkey. © 2021 International Parkinson and Movement Disorder Society.

A treatable cause of myelopathy and vision loss mimicking neuromyelitis optica spectrum disorder: late-onset biotinidase deficiency.

Biotinidase deficiency is characterized by severe neurological manifestations as hypotonia, lethargy, ataxia, hearing loss, seizures and developmental retardation in its classical form. Late-onset biotinidase deficiency presents distinctly from the classical form such as limb weakness and vision problems. A 14-year-old boy presented with progressive vision loss and upper limb weakness. The patient was initiated steroid therapy with a preliminary diagnosis of neuromyelitis optica spectrum disorder due to the craniospinal imaging findings demonstrating optic nerve, brainstem and longitudinally extensive spinal cord involvement. Although the patient exhibited partial clinical improvement after pulse steroid therapy, craniocervical imaging performed one month after the initiation of steroid therapy did not show any regression. The CSF IgG index was <0.8 (normal: <0.8), oligoclonal band and aquaporin-4 antibodies were negative. Metabolic investigations revealed a low biotinidase enzyme activity 8% (0.58 nmoL/min/mL; normal range: 4.4 to 12). Genetic testing showed c.98-104delinsTCC and p.V457 M mutations in biotinidase (BTD) gene. At the third month of biotin replacement therapy, control craniospinal MRI demonstrated a complete regression of the lesions. The muscle strength of the case returned to normal. His visual acuity was 7/10 in the left eye and 9/10 in the right. The late-onset form of the biotinidase deficiency should be kept in mind in all patients with myelopathy with or without vision loss, particularly in those with inadequate response to steroid therapy. The family screening is important to identify asymptomatic individuals and timely treatment.

Ictal urinary urge: localization and lateralization value in a pediatric case.

BACKGROUND: Ictal urinary urge is a rare autonomic symptom usually lateralizing to the non-dominant hemisphere and localizing to the temporal lobe. CASE REPORT: A 12-year-old boy was referred with desire to void and contraction of the left arm. The history of the case revealed tickling and an unpleasant rising feeling in the stomach and sense of fear lasting for 1 year. He had been evaluated and treated several times with the diagnosis of gastroesophageal reflux and cystitis. His cranial MRI displayed an intra-axial mass formation on the right temporal lobe. Pathological findings were consistent with a low-grade glial mass. CONCLUSION: Ictal urinary urge has a considerable value both for localization and lateralization of seizures.

Changing views of cerebral palsy over 35 years: the experience of a center.

In this study, it was aimed to evaluate the demographic and clinical characteristics of cerebral palsy (CP) cases over a 35-year period. Findings of 442 patients with CP followed from 1995 to 2006 (Group 2) were compared with 208 patients with CP followed between 1972 and 1994 (Group 1) in the same pediatric neurology division. Ratios of both prematurity (38% vs. 17.7%) and very low birth weight (VLBW) infants (13.8% vs. 1.5%) significantly increased in Group 2. There was also a four-fold increase in cesarean delivery in Group 2 (42.3% vs. 9.6%). A significant increase in the rate of early diagnosis during the first year was also found in this group (56.9% vs. 39.4%). The rate of spastic diparesis cases has significantly increased (33.7% vs. 7.7%), while the rate of spastic tetraparesis cases has significantly decreased (63.5% vs. 37.3%). It was seen that preventable risk factors continue today.

Video/EEG recording of myoclonic absences in GLUT1 deficiency syndrome with a hot-spot R126C mutation in the SLC2A1 gene.

Glucose transporter type 1 deficiency syndrome (GLUT1DS) is an inborn error of brain energy metabolism characterized by impaired glucose transport into the brain. A classic phenotype comprising epilepsy, mental retardation, an often paroxysmal disorder, and several subtypes has been described. Although typical absences are frequent in GLUT1DS, myoclonic absence seizures are rarely reported. Here we describe a novel Turkish patient with a hot-spot mutation (R126C) in the SLC2A1 gene who presented with unusual myoclonic absence epilepsy and paroxysmal shivering. The case is discussed in view of eight other cases carrying the R126C mutation.

A rare cause of recurrent stroke in childhood: left atrial rhabdomyosarcoma.

UNLABELLED: We present a case of recurrent stroke secondary to cardiac rhabdomyosarcoma. The detected prothrombotic mutations at the first attack had seemed to be the main cause, but the echocardiography performed at the recurrence revealed the actual underlying cause of stroke. CONCLUSION: The aetiological investigation into childhood stroke should absolutely include echocardiography regardless of the presence of other risk factors.

Febrile seizures: interleukin 1beta and interleukin-1 receptor antagonist polymorphisms.

In order to investigate the association between IL-1beta -511 C-->T and IL-1 receptor antagonist intron 2 variable tandem repeat polymorphisms, and febrile seizures in children, 90 children (mean age, 19.7 +/- 11.2 months) diagnosed with febrile seizure and 106 healthy controls (mean age, 14.2 +/- 3.6 months) with no seizure or neurologic events were included in the study. The polymorphisms were analyzed using restriction fragment length polymorphism and agarose gel electrophoresis methods. In the patient group, the frequencies of IL-1beta genotypes CC, CT, and TT were 24.4%, 52.2%, and 23.3%, respectively, compared with 38.7%, 50.95%, and 10.4%, respectively, in the control group. The TT genotype was significantly more common in the patient group than in the control group (P = 0.044), and the T allele frequency was significantly higher in the patient group (0.50 vs 0.36, P = 0.040). Among the three genotypes (RN1/1, RN1/2, and RN2/2) of the IL receptor antagonist gene variable tandem repeat polymorphisms, the frequency of both the RN2/2 genotype and the RN2 allele were significantly higher in the patient group (P = 0.007). Also RN2 allele frequency was found higher in patient group than controls (0.29 vs 0.15, P = 0.020). IL-1beta -511 and IL-1 receptor antagonist intron 2 variable tandem repeat polymorphisms may be involved in susceptibility to febrile convulsions in children.

Extreme delta brush activity: Could it be a marker for early diagnosis and prognosis of anti- NMDA (N-methyl-D-aspartate) encephalitis?

Autoimmune encephalitis should be excluded in unexplained encephalitis. A significant portion of autoimmune encephalitis in childhood is anti- NMDA encephalitis. However, neuroimaging and routine diagnostic tests are inadequate, diagnosis sholud be confirmed by the demonstration of autoantibodies. The treatment may be delay in this process. Extreme delta brush waves are unique electroencephalography pattern, seen in some of Anti-NMDA encephalitis, useful for early diagnosis. Extreme delta brush activity is associated with prolonged hospitalization and illness. Despite of these, the specificity and sensitivity of this pattern is not-known clearly. We present a five years old boy with the loss of consciousness, involuntary movements, intermittant generalized tonic clonic seizures and extreme delta brush activity in electroencephalography.

Açiklanamayan ensefalit klinigi ile basvuran hastalarda otoimmun ensefalitler dislanmalidir. Çocukluk çaginda otoimmun ensefalitlerin önemli kismi anti-NMDA (N-metil-D-aspartat) ensefalitidir. Ancak nörogörüntüleme ve rutin tetkikler tanida yetersiz kalmakta, kesin tani otoantikorlarin gösterilmesi ile konulmaktadir. Bu süreçte tedavide gecikme olabilmektedir. Anti-NMDA ensefalitli olgularinin bir kisminda erken dönemde elektroensefalogramda saptanan özgül bir örnegi olan asiri delta 'brush' tanida gecikmeyi önlemektedir. Asiri delta 'brush' aktivitesi, uzamis hastalik ve hastanede kalma süresi ile iliskilendirilmistir. Tüm bu bilinenlere ragmen bu örnegin özgüllügü ve duyarliligi tam olarak bilinmemektedir. Bu yazida bilinç kaybi, istemsiz hareketler ve sik jeneralize tonik klonik nöbetler ile basvuran, elektroensefalografisinde asiri delta 'brush' gözlenen bes yasinda erkek bir hasta sunuldu.

Semiologic seizure classification: the effectiveness of a modular education program for health professionals in pediatrics.

We tested the effectiveness of a modular education program on Semiologic Seizure Classification (SSC) in helping health professionals in pediatrics correctly recognize seizures in childhood. The study samples included 20 residents, 20 nurses, and 10 EEG technicians working in pediatrics. The study was conducted in two steps. First, a modular education program comprising CD-ROMs including 58 video clips of epileptic seizures designed for the original SSC was developed. Second, each participant took a pretest by viewing the pretest CD-ROM, participated in the modular education program with a CD-ROM, and finally took a posttest with the posttest CD-ROM. The pretest scores were found to be low in each subgroup of the study population: the average scores were 8 for the residents (minimum 4-maximum 10), 2 for the nurses (min 0-max 4), and 2.5 for the EEG technicians (min 0-max 8). After participating in the modular education program, correct recognition of seizures increased in the posttest: the average scores were 15.5 for the residents (min 9-max 20), 15 for the nurses (min 13-max 20), and 13.5 for the EEG technicians (min 3-max 19). The increase in the scores in the subgroups and in all study groups in general was found to be statistically significant (P<0.05). The modular education program developed for SSC was found to be highly effective in teaching health professionals working in general pediatric clinics to correctly recognize seizure types.

The effect of depression on academic achievement in children with epilepsy.

In this cross-sectional study our aim was to evaluate the effect of depression on academic achievement in children with epilepsy and low school performance. Fifty-one children with epilepsy and low school performance were evaluated with the Children's Depression Inventory (CDI) to measure depressive symptoms. School performance was evaluated with Achenbach's Child Behavior Checklist (CBCL) and the Teacher Report Form (TRF). Children diagnosed with depressive spectrum disorders received medical therapy. All tests were administered in the first interview and repeated at the end of 6 months of therapy. Forty-three children completed the study. The patients were evaluated with DSM-IV diagnostic criteria. Accordingly, 9 (20.9%) children had Major Depressive Disorder (MDD) and 4 (9.3%) had Depressive Disorder, Not Otherwise Specified (DD-NOS). All children with MDD and DD-NOS received antidepressant medication, but only seven of them completed treatment. Posttreatment CDI scores were significantly lower, and TRF scores also improved. Pediatric neurologists should be aware of the possibility of depressive disorders in children with epilepsy, especially in those with low school performance.

Prevalence and severity of malnutrition in pediatric neurology outpatients with respect to underlying diagnosis and comorbid nutrition and feeding related problems.

Tekin H, Tekgül H, Yilmaz S, Arslangiray D, Reyhan H, Serdaroglu G, Gökben S. Prevalence and severity of malnutrition in pediatric neurology outpatients with respect to underlying diagnosis and co-morbid nutrition and feeding related problems. Turk J Pediatr 2018; 60: 709-717. This study aimed to determine prevalence and severity of malnutrition with respect to underlying diagnosis and co-morbid nutrition and feeding related problems in pediatric neurology outpatients. A total of 1,057 pediatric neurology outpatients (7.2±5.4 years, 56.9% males) were included. Data on patient demographics, neurological diagnosis, anthropometrics and Nutritional Questionnaire (NQ) for co-morbid feeding difficulties and nutritional problems were recorded. Epilepsy (45.2%) was the most common diagnosis, while prevalence of acute malnutrition was 17.7%. Nutritional support resulted in a significant decrease in the percentage of malnourished patients (from 17.1% to 6.7%, p˂0.001) and significant improvement in weight for height scores (increased to 81.42±8.17, p=0.045). In NQ-10 item assessment, at least one item was positive in 66.0% (gastrointestinal in 54.3%) of acutely malnourished patients, more commonly in severe acute malnutrition. NQ 4- item set of `red flags` revealed that prolonged meal time, meal time stressful to child or parent, lack of weight gain not just weight loss and cough during feeding were evident in 45.2%, 46.8%, 36.7% and 14.8% of patients with acute malnutrition, respectively; and more common in patients with severe malnutrition. NQ 4-item set of `red flags` was associated with high sensitivity (95%) and specificity (88%) in detection of malnutrition. In conclusion, our findings in a cohort of pediatric neurology outpatients revealed that 17.1% of overall patients were acutely malnourished along with higher prevalence of malnutrition in underlying diagnosis of cerebral palsy and higher likelihood of nutritional problems and feeding difficulties in severe malnutrition. Given the association of 6-month nutritional support with improved anthropometrics and decreased percentage of malnourished patients, our findings indicate that increased awareness of nutritional status and nutritional support is essential for the care of neurologically impaired children with potential benefit of identifying early feeding/swallowing related signs of malnutrition.

Arterial ischemic stroke in childhood: risk factors and outcome in old versus new era.

Risk factors of children with arterial ischemic stroke were retrospectively evaluated. The children were grouped according to values on developing diagnostic tools: 13 in the old era (1987-1994) and 18 in the new era (1995-2004). The old era battery included 5 tests: protein C, protein S, antithrombin, lupus anticoagulants, and anticardiolipin antibodies. The new era battery added 5 more tests: homocystine level, factor VIII level, mutations for factor V Leiden and prothrombin G20210A, and lipoprotein (a) level. At least 1 risk factor was found in 5 of 13 children (38.5%) in the old era and in 8 of 18 (44.4%) in the new era. The extended battery for prothrombotic disorders revealed 7 risk factors in 4 children (22.2%) in the new era, whereas the limited battery identified a single risk factor in 1 child (7.7%) in the old era. For the correct etiologic identification, prothrombotic risk factors should be extensively evaluated in patients with arterial ischemic stroke.

Miller Fisher syndrome: a case with pattern of pure sensory polyneuropathy concomitant with anti-GQ1B antibody.

Miller Fisher syndrome is characterized by the acute onset of ophthalmoplegia, ataxia, and areflexia. Anti-GQ1b antibodies are useful markers for the differential diagnosis of Miller Fisher syndrome. We describe the case of a seven-year-old male who presented with a four-day history of diplopia and ophthalmoplegia following a febrile flu-like illness with sore throat. On examination he was found to have ataxia, areflexia and ophthalmoplegia, and a diagnosis of Miller Fisher syndrome was made after the exclusion of other conditions and concomitant with electrophysiological findings on electromyography. Although this disorder has a rare incidence, it should still be considered in the differential diagnosis in our country.

Chronic inflammatory demyelinating polyradiculopathy: an atypical pediatric case complicated with phrenic nerve palsy.

An atypical form of chronic inflammatory demyelinating polyneuropathy (CIDP) complicated with phrenic nerve palsy is presented with clinical and electrophysiologic features. A seven-year-old girl had initial presentation mimicking Guillain-Barré syndrome based on electrophysiologic characteristics. Between 7-11 years of age, she had five recurrences of subacute onset of weakness which usually developed over at least 2-4 months and progressed to loss of ambulation and to respiratory insufficiency. Radiologic examinations revealed unilateral phrenic nerve palsy associated with CIDP. Our patient demonstrated the rare association of CIDP and phrenic nerve palsy, resulting in diaphragmatic paralysis and respiratory failure.

Targeted next generation sequencing: the diagnostic value in early-onset epileptic encephalopathy.

We investigated the genetic background of early-onset epileptic encephalopathy (EE) using targeted next generation sequencing analysis. Thirty sporadic or familial cases associated with early-onset EE were included. An early-onset EE gene panel including sixteen genes (ARX, CDKL5, CNTNAP2, FOLR1, FOXG1, LAMC3, MBD5, MECP2, NTNG1, PCDH19, PNKP, SCN1A, SCN1B, SCN2A, STXBP1, KCNQ2) was constituted. Nine definite and three potential causal mutations in 30 cases (40 %) were identified. All mutations presented heterozygously except one. Five mutations had been previously detected (SCN1A c.842C > T (p.P281L), SCN1A c.4907G > C (p.A1636P), PCDH19 c.1091dupC (p.Y366LfsX10), CNTNAP2 c.416A > G (p.N139S), MBD5 c.3595G > A(p.Y1199R) while other seven were novel (SCN1A c.4907G > C (p.A1636P), SCN2A c.4633A > G (p.M1545 V), CDKL5 c.197_198delCT (p.L67QfsX23), FOXG1 c.*6C > T, KCNQ2 c.560c > A (p.S187Y), KCNQ2 c.835G > A (p.G279S), STXBP1 c.1105G > T (p.E369X)). Eight of 12 mutations were de novo. While the overall mutation detection rate was found 40 %, this ratio was 55.5 % (10 out of 18) and 16.6 % (2 out of 12) in patients born to nonconsanguineous parents and consanguineous parents, respectively. In conclusion, a selected gene panel approach including mainly de novo and channel-encoding genes will result in the detection of variants in isolated patients and support the channelopathy theory underlying epilepsy, while consanguineous families will remain less diagnosed. Targeted next generation sequencing approach is an efficient diagnostic tool in the detection of the genetic basis of early-onset EE.

Genetic Landscape of Congenital Myasthenic Syndromes From Turkey: Novel Mutations and Clinical Insights.

Congenital myasthenic syndromes are clinically and genetically heterogeneous disorders of neuromuscular transmission. Most are treatable, but certain subtypes worsen with cholinesterase inhibitors. This underlines the importance of genetic diagnosis. Here, the authors report on cases with genetically proven congenital myasthenic syndromes from Turkey. The authors retrospectively reviewed their experience of all patients with congenital myasthenic syndromes, referred over a 5-year period (2011-2016) to the Child Neurology Department of Dokuz Eylül University, Izmir, Turkey. In addition, PubMed was searched for published cases of genetically proven congenital myasthenic syndromes originating from Turkey. In total, the authors identified 43 (8 new patients, 35 recently published patients) cases. Defects in the acetylcholine receptor (n = 15; 35%) were the most common type, followed by synaptic basal-lamina associated (n = 14; 33%) and presynaptic syndromes (n = 10; 23%). The authors had only 3 cases (7%) who had defects in endplate development. One patient had mutation GFPT1 gene (n = 1; 2%). Knowledge on congenital myasthenic syndromes and related genes in Turkey will lead to prompt diagnosis and treatment of these rare neuromuscular disorders.

Bone mineral status in pediatric outpatients on antiepileptic drug monotherapy.

Drug-induced osteopenia has been reported in institutionalized children on chronic antiepileptic drug therapy. The aim of this study was to assess longitudinally bone mineral status in pediatric outpatients on antiepileptic drug monotherapy. The study group consisted of 30 ambulatory children on a normal diet: 15 on valproic acid, 11 on carbamazepine, and 4 on phenobarbital monotherapy. Bone mineral density, serum active vitamin D (1,25-dihydroxyvitamin D), and certain biochemical markers of bone formation (calcium, phosphorus, alkaline phosphatase, intact parathyroid hormone, osteocalcin, calcitonin, and urinary calcium to serum creatinine and urinary phosphorus to serum creatinine ratios) were studied at the beginning of antiepileptic drug monotherapy and at the end of 2 years of treatment. Age- and sex-specific Z-scores of bone mineral density were measured at anterior-posterior L2-L4 by dual-energy x-ray absorptiometry. Drug-induced osteopenia was defined in only two patients (one on carbamazepine and the other on phenobarbital monotherapy), with Z-scores of bone mineral density less than -1.5. Serum levels of active vitamin D and biochemical markers were not significantly correlated with the Z-scores of bone mineral density. We detected a frequency of antiepileptic drug-induced osteopenia of 6.7% in pediatric outpatients after 2 years of monotherapy. However, osteopenia was not attributed to a defect in serum active vitamin D production owing to hyperparathyroidism in children on antiepileptic drug monotherapy.

Central core disease: atypical case with respiratory insufficiency in an intensive care unit.

Central core disease is a rare congenital myopathy characterized by formation of typical cores in myofibrils. We report an atypical case of central core disease with respiratory insufficiency in the late stage of congenital myopathy. A 13-year-old girl was admitted to the intensive care unit with the diagnosis of respiratory distress syndrome. Ventilatory support was initiated. After 2 weeks of follow-up, the Division of Pediatric Neurology was consulted owing to the failure to wean her from the ventilator. Clinical and electromyographic features were in favor of primary muscle disease. Muscle biopsy revealed typical cores in type 1 muscle fibers, which were diagnostic for central core disease. This case was presented to emphasize that patients with respiratory distress who cannot be weaned from the ventilator should be evaluated for central core disease with an atypical presentation.