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Objectives: Migraine is a common disorder in children, and its prophylaxis with minimal side effects is momentous. This study aimed to compare the efficacy of Pregabalin and Sodium Valproate in preventing migraine attacks., Material & Methods: Sixty-four children (aged 6-18) with migraines were recruited, as defined by Internation Headache Criteria (ICHD-III). They were randomly assigned to two groups: Sodium Valproate (n=32) and Pregabalin (n=32). The minimum dosage of drugs was prescribed in both groups. The patients were followed for four months. The parameters such as frequency, intensity, duration of migraine attacks, and the number of painkillers that the patients used monthly were recorded. The Spence Children's anxiety scale was also used to evaluate medications' effect on patients' anxiety levels., Results: Two medications were equally effective in reducing the intensity and duration of attacks. Additionally, their effect on reducing the anxiety level of patients was equal. There was a significant difference between the effect of drugs on the frequency of migraine attacks at the end of the first and fourth months and the number of painkillers used at the end of the fourth month. The frequency of attacks was decreased by more than 50% in twenty-eight patients (90%) of Pregabalin recipients and twenty-one patients (84%) of Sodium Valproate recipients., Conclusion: Considering the better effect of Pregabalin in the reduction of frequency of migraine attacks and pain-reducing medications consumption, Pregabalin could be a proper substitute for Sodium Valproate for prophylactic migraine treatment in children., Competing Interests: The authors declared no conflict of interest.

Thalassemia syndromes are the most prevalent monogenic hemoglobinopathy in the world. In Iran, thalassemia is a public health problem because this country has been located on the thalassemia belt. In recent decades, considering that the life expectancy of patients with thalassemia has dramatically improved, some unrecognized complications have emerged in these individuals. One of these complications is a hypercoagulable state that may lead to thromboembolic events (TEE). The TEE may involve any organ in the body, including the central nervous system. Ischemic cerebrovascular events in thalassemic patients have been divided into two categories, namely overt stroke and silent cerebral infarcts (SCI). Overt stroke often develops in patients with beta-thalassemia major; however, patients with thalassemia intermedia usually suffer from SCI. This review article discusses brain vascular involvement., Competing Interests: The author has no conflict of interest with the subject matter of the present study.

Objectives: Stuttering is a common problem at all ages that is required to be treated since childhood. Atomoxetine is currently used for the treatment of attention deficit hyperactivity disorder (ADHD). It can be effective for the treatment of stuttering due to its selective inhibition of norepinephrine reuptake and dopaminergic properties. Therefore, this randomized controlled trial aimed to evaluate the effect of atomoxetine on children's stuttering., Materials & Methods: The children aged 4-12 years and diagnosed with stuttering, referred to Pediatric Neurology and Psychology clinics , were randomly divided into experimental (n=50) and control (n=50) groups. One group received atomoxetine plus speech therapy, and the other group received only speech therapy. Both groups completed the Stuttering Severity Instrument-Fourth Edition at the baseline (on the first visit) and 3 months after the intervention. The results were compared between the two groups using SPSS software (version 21)., Results: Most of the children (67%) were male. Moreover, 24%, 46%, and 30% of the subjects were within the age ranges of < 60, 60-95, and > 95 months, respectively. Nearly half of the patients (52%) had a positive family history of stuttering. Stuttering severity was the highest within the age range of 60-95 months, in left-handed children, in those who used formula, and in those who felt insecure in the family; however, there was no difference in stuttering severity based on child's gender, concomitant ADHD, multilingualism, facial or movement tics, sleeping hours, and using teats. The mean stuttering severity reduced in both groups (P<0.001), with a greater decrease in the experimental group, compared to that of the control group (P=0.011)., Conclusion: Atomoxetine plus speech therapy is effective for the treatment of children's stuttering and can be used as a complementary treatment strategy in such patients., Competing Interests: The present study wasnt financially supported by anyone, (© 2022 The Authors.)

Objectives: The current study aimed at identifying the role of seizure types and related clinical features in differentiation between neurometabolic disorders and other causes of seizure., Materials & Methods: The current cross sectional study was conducted at two referral children hospitals in Tehran, Iran, from 2011 to 2018. The study population included 120 patients presenting with seizure due to neurometabolic disorders and 120 cases due to other causes. The types of seizure and related clinical findings were assessed in both groups., Results: There was a significant difference in the frequency of seizure types in the two groups. Tonic and myoclonic seizures as well as infantile spasm were observed more commonly in the patients with neurometabolic disorders, while atonic, partial and generalized tonic-clonic seizures were more common in the control group. In addition, frequency of refractory seizure, age at onset of seizure, and pattern of involvement in brain imaging were helpful for differentiation., Conclusion: The pattern of seizure and related findings varied in patients with metabolic disorders, and was helpful for diagnosis. Thus, these factors can contribute to early diagnosis and treatment., Competing Interests: The authors declared no conflict of interest.

Gaucher disease (GD) is a rare inherited metabolic disorder and the most common lysosomal storage disorder, caused by a deficiency in glucocerebrosidase enzyme activity. It has been classified according to the neurological manifestations into three types: type 1, without neuropathic findings, type 2 with acute infantile neuropathic signs and type 3 or chronic neuropathic form. However, report of new variants has led to the expansion of phenotype as a clinical phenotype of GD considered as a continuum of phenotypes. Therefore, it seems that a new classification is needed to cover new forms of the disease., Competing Interests: The authors declare that there is no conflict of interests.

Objective: This study was conducted to predict the response to treatment in patients treated with anti-epilepsy drugs., Material and Methods: This analytical questionnaire-based study was conducted in 2014 among 128 patients with epilepsy admitted to Mofid Children's Hospital, Tehran, Iran. The inclusion criteria were children 2 months to 12 yr of age with epilepsy and patients who experienced fever and seizure attacks at least once were excluded from the study. Patients were followed up for 6 months and the response to their treatment was recorded. The good response to treatment was defined as the absence of seizure with two drugs during follow up., Results: Seventy-two patients (56.3%) were boys. The age of the first seizure was under 2 yr old in 90 patients (70.3%). History of febrile convulsion, family history of epilepsy and history of asphyxia was found in 16 (12.5%), 41 (32%), and 27 (21.1%) patients, respectively. Seizure etiology was idiopathic in 90 patients (70.3%), and the number of seizures was 1-2 in 36 patients (28.1%). Overall, 57 patients (44.5%) had cerebral lesion according to CT scan or MRI, and EEG was abnormal in 101 patients (78.9%). In 6-month follow-up, 40 patients (31.3%) responded well to the treatment and 88 patients (68.8%) responded poorly to the treatment. History of asphyxia (OR = 6.82), neonatal jaundice (OR = 2.81) and abnormal EEG (OR = 0.19) were effective factors in response to treatment., Conclusion: Abnormal EEG is an effective factor in treatment response in the children studied., Competing Interests: The authors declare that there is no conflict of interest.

Objective: Gaucher disease (GD) is a rare inborn error of metabolism, classified as a lipid storage disorders. This disease is caused by a deficiency in glucocerebrosidase enzyme. It has been classified according to the presence or absence of neurological symptoms into the following types: type 1 non-neuropathic, type 2 acute infantile neuropathic and type 3 or chronic neuropathic. We evaluated neurological symptoms in patients with GD1 and GD3 and compared both of these groups., Materials & Methods: Eleven patients were identified according to their clinical presentation and the presence of disease confirmed by genetic testing, from 2006-2016, at the Mofid Children Hospital Clinic, Tehran, Iran. We included eight patients with GD 1 and three patients with GD3. Careful neurological examination was performed on these patients during treatment by pediatric neurologist., Results: Patients with GD1 had some neurological symptoms including cognitive impairment, developmental disability, behavioral disorder, microcephaly and increased deep tendon reflexes (DTR). Of course, neurological signs in patients with type 3 of GD were different and were included seizures, supranuclear gaze palsy, cerebellar signs, and ataxia., Conclusion: The current nomenclature for 3 types of Gaucher disease does not meet all clinical symptoms. Patients with GD1 display many neurological deficits in young ages not reported adequately earlier., Competing Interests: The authors declare that there is no conflict of interest.

Objective: Anticonvulsant drugs can cause various forms of skin drug reactions, ranging from exanthema to severe blistering reactions. An association between HLA-B*1502 allele and severe skin reactions have been reported., Materials & Methods: Fifteen patients with severe skin reactions following treatment with anticonvulsant drugs (Carbamazepine, lamotrigine, phenobarbital, primidone) and 15 controls (age-matched epileptic patients taking similar anticonvulsants without drug eruption) were included. They were referred to Mofid Children's Hospital in Tehran, Iran, between Jan 2012 to Jan 2014. Genomic DNA was extracted from peripheral blood of all patients and HLA- B*1502 genotype was detected by real-time PCR., Results: None of the patients was positive for HLA- B*1502, but two patients in control group had positive HLA- B*1502., Conclusion: The HLA- B*1502 is not correlated with severe anticonvulsant drugs -induced skin reactions in Iranian children., Competing Interests: The authors declare that there is no conflict of interest.

Objective: Adrenoleukodystrophy disorder is one of the x-linked genetic disorders caused by the myelin sheath breakdown in the brain. In this study, we present 4 yr experience on this disorder., Materials & Methods: The patients diagnosed as adrenoleukodystrophy in the Neurology Department of Mofid Children's Hospital in Tehran, Iran from 2010 to 2014 were enrolled into the study. The disorder was confirmed by neuroimaging and clinical findings along with genetic and neurometabolic assessment at Reference Laboratory in Germany. We assessed age, gender, past medical history, developmental status, clinical manifestations, and neuroimaging findings of populous family with adrenoleukodystrophy., Results: All of the patients were one populous family with high rate of consanguineous marriages. This disorder was confirmed by genetic assessment, VLCFA and brain MRI. c.253&#95;254insC, p.R85Pfs112* was found in heterozygote state and the VLCFA assessment showed the typical pattern for adrenoleukodystrophy/ adrenomyeloneuropathy. This diagnosis was in agreement with the family history and the clinical history of the patient. Since there have been a number of cases in patient's family in the past, so intensive follow-up on the family especially detection the female members of the family of childbearing age was recommended. The amount of C-26, C24/C22 and C26/C22 was elevated. All patients with the same genotype had wide ranges of clinical presentation., Conclusion: Early diagnose of this disease might help us for early intervention and prenatal diagnosis for the disease in next siblings.

Objective: We aimed to investigate the clinical and para clinical manifestations of neuro metabolic disorders, in patients who presented by neuro developmental delay in their neuro developmental milestones., Materials & Methods: The patients diagnosed as neuro developmental delay and regression with or without seizure at the Neurology Department of Mofid Children Hospital in Tehran, Iran between 2004 and 2014 were included in our study. These patients diagnosed as neuro developmental delay by pediatric neurologists in view of diagnostic /screening neuro developmental assessment tests. The patients who completed our inclusion criteria as neuro metabolic disorders were evaluated in terms of metabolic and genetic study in referral lab., Results: Overall, 213 patients with neurometabolic disorders were diagnosed. 54.3% of patients were male. The average age of patients was 41 +-46.1 months. 71.4% of parent's patients had consanguinity of marriages. Eighty seven percent of patients had developmental delay (or/and) regression. 55.5% of them had different type of seizures. Overall, 213 patients with 34 different neurometabolic disorders were diagnosed and classified in the 7 sub classes, consisting of: 1- organic acidemia and aminoacidopathy (122 patients), 2-storage disease (37 patients) 3- eukodystrophy (27 patients), other classes consisted: lipid oxidation disorders, urea cycle disorders, progressive myoclonic epilepsy; and peroxizomal disorders (27 patients)., Conclusion: In patients with developmental delay or regression, with or without seizure, abnormal neurologic exam along with positive family history of similar disorder or relative parents, abnormal brain imaging with specific patterns, neurometabolic disorders should be considered as one of the important treatable diseases.

Objective: Homocystinuria is a neurometabolic diseases characterized by symptoms include Neurodevelopmental delay, lens dislocation, long limbs and thrombosis., Materials & Methods: The patients who were diagnosed as homocystinuria marfaniod habits, seizure in the Neurology Department of Mofid Children's Hospital in Tehran, Iran between 2004 and 2014 were included in our study. The disorder was confirmed by clinical andneuroimaging findings along withneurometabolic and genetic assessment fromreference laboratory in Germany. We assessed age, gender, past medical history, developmental status, clinical manifestations, and neuroimaging findings of 20 patients with homocystinuria., Results: A total of 75% of patients were offspring from consanguineous marriages. A total of 95% of patients had a history of developmental delay and 40% had developmental regression. A total of 75% had seizures from these 45% showed refractory seizures. Seizures among 13 patients werecontrolled with suitable homocystinuria treatment. The patients with homocystinuriawere followed for approximately 10 years and the follow-ups showed that the patients with an early diagnosis and treatment had more favorable clinical responses for growth index, controlled refractory seizures, neurodevelopmental status, and neuroimaging findings. Neuroimaging findings include brain atrophy and/or white matter involvement., Conclusion: According to the results of this study, we suggest that early assessment and detectionplayan important role in the prevention of disease progression and clinical signs. Homocystinuria in patients with a positive family history, developmental delays, or regression, refractory, or recurrent seizures should take precedence over other causes.

Objective: Metachromatic leukodystrophy disorder (MLD) is one of the rare neurometabolic diseases caused due to lack of saposin B and arylsulfatase A enzyme deficiency., Materials & Methods: Eighteen patients diagnosed as metachromatic leukodystrophy in the Neurology Department of Mofid Children's Hospital in Tehran, Iran between 2010 and 2014 were included in our study. The disorder was confirmed by clinical, EMG-NCV, arylsulfatase A enzyme checking and neuroimaging findings along with neurometabolic and genetic assessment from reference laboratory in Iran. We assessed age, gender, past medical history, developmental status, clinical manifestations, and neuroimaging findings of 18 patients with metachromatic leukodystrophy., Results: From 18 patients, 80% were offspring from consanguineous marriages. A family history of metachromatic leukodystrophy disease was positive for four patients. Twelve patients had late infantile form of this disorder and six patients had juvenile form. A history of tonic type seizure was positive in 20% of the patients and tonic spasm was confirmed with clinical information. Electromyographgraphy (EMG) in 96% of patients was abnormal with demyelinating sensorimotor neuropathy pattern. MRI in all patients showed the leukodystrophic pattern as arcuate fibers sparing and subcortical rim in white matter and periventricular involvement. Our diagnosis was confirmed by EMG-NCV findings with sensorimotor neuropathy pattern and the assessment of arylsulfatase A enzyme function., Conclusion: MLD is an inheritance metabolic disorder, which was confirmed by the assessment of arylsulfatase A enzyme function, peripheral blood leukocyte that assessed in a referral laboratory in Iran.

Objective: Propionic acidemia is one of the rare congenital neurometabolic disorders with autosomal recessive inheritance. This disorder is caused by a defect in the propionyl-CoA carboxylase enzyme and can be presented with life-threatening ketoacidosis, lethargy, failure to thrive, and developmental delay., Materials & Methods: The patients diagnosed as having propionic acidemia in Neurology Department of Mofid Children's Hospital in Tehran, Iran, between 2002 and 2012 were include in our study. This disorder was confirmed by clinical manifestations, neuroimaging findings, and neurometabolic assessment in the reference laboratory in Germany. Our study was conducted to define the sex, age, gender, past medical history, developmental status, clinical findings, and neuroimaging manifestations in 10 patients with propionic acidemia., Results: Seventy percent of patients were offspring of consanguineous marriages. In this study, only one patient had microcephaly at birth, but at detection time, 30% of patients had head circumference and weight below the 3rd percentile. The patients were followed for approximately 5 years and this follow-up showed that the patients with early diagnosis had a more favorable clinical response. Neuroimaging findings included brain atrophy, white matter and globus pallidus involvement., Conclusion: Finally we suggest that early diagnosis and treatment have an important role in the prevention of disease progression.

Objective: Canavan's disease is a lethal illness caused by a single gene mutation that is inherited as an autosomal recessive pattern. It has many different clinical features especially in the non-Ashkenazi Jewish population., Material & Methods: 45 patients were referred to the Pediatric Neurology Department of Mofid Children's Hospital in Tehran-Iran from 2010-2014 with a chief complaint of neuro developmental delays, seizures, and neuroimaging findings of leukodystrophy were included in this study. Magnetic Resonance Spectrometry (MRS) and neuro metabolic assessment from a referral laboratory in Germany confirmed that 17 patients had Canavan's disease., Results: Visual impairment, seizure, hypotonia, neuro developmental arrest, and macrocephaly were the most consistent findings in the patients in this study. Assessments of neuro developmental status revealed that 13 (76%) patients had neuro developmental delays and 4 (24%) patients had normal neuro development until 18 months of age and then their neuro developmental milestones regressed. In this study, 100% of cases had macrocephalia and 76% of these patients had visual impairment. A history of seizures was positive in 8 (47%) patients and began around 3 months of age with the most common type of seizure was tonic spasm. EEGs were abnormal in all epileptic patients. In ten of the infantile group, we did not detect elevated level of N-acetylaspartic acid (NAA) in serum and urine. However, the MRS showed typical findings for Canavan's disease (peaks of N-acetylaspartic acid)., Conclusion: We suggest using MRS to detect N-acetylaspartic acid as an acceptable method for the diagnosis of Canavan's disease in infants even with normal serum and urine N-acetylaspartic acid levels.

Objective: GM2-Gangliosidosis disease is a rare autosomal recessive genetic disorder that includes two disorders (Tay-Sachs and Sandhoff disease).These disorders cause a progressive deterioration of nerve cells and inherited deficiency in creating hexosaminidases A, B, and AB., Materials & Methods: Patients who were diagnosed withGM2-Gangliosidosis in the Neurology Department of Mofid Children's Hospital in Tehran, Iran from October 2009 to February 2014were included in our study. The disorder was confirmed by neurometabolic and enzyme level detection of hexosaminidases A, B, and AB in reference to Wagnester Laboratory in Germany. We assessed age, gender, past medical history, developmental status, clinical manifestations, and neuroimaging findings of 9 patients with Sandhoff disease and 9 with Tay Sachs disease., Results: 83% of our patients were the offspring of consanguineous marriages. All of them had a developmental disorder as a chief complaint. 38%of patients had a history of developmental delay or regression and 22% had seizures. The patients with Sandhoff and Tay Sachs disease were followed for approximately 5 years and the follow-up showed all patients were bedridden or had expired due to refractory seizures, pneumonia aspiration, or swallowing disorders. Neuro-imaging findings included bilateral thalamic involvement, brain atrophy, and hypo myelination in near half of our patients (48%)., Conclusion: According to the results of this study, we suggest that cherry-red spots, hyperacusis, refractory seizures, and relative parents in children with developmental delay and/or regression should be considered for assessment of GM2-Gangliosidosis disease.

Objective: Phenylketonuria is one of the most common metabolic disorders and the first known cause of mental retardation in pediatrics. As Screening for phenylketonuria (PKU) is not a routine neurometabolic screening test for neonates in Iran, many PKU cases may be diagnosed after developing the clinical symptoms. One of the findings of PKU is myelination disorders, which is seen as hypersignal regions in T2-weighted (T2W) and FLAIR sequences of brain MRI. The aim of our study was to assess MRI changes in PKU patients referred to Mofid Children's Hospital, 2010-2011., Materials & Methods: We studied all PKU cases referred to our clinic as a referral neurometabolic center in Iran for brain MRI and assessed the phenylalanine level at the time of Imaging. The mean phenylalanine level (in one year), clinical manifestations, and MRI pattern based on Thompson scoring, were evaluated., Results: The mean age of our study group was 155±99 months and the mean diagnosis age was 37±27.85 months. There were 15 patients with positive and 15 with negative family history. The mean phenylalanine level at the time of imaging was 9.75±6.28 and the mean 1 year phenylalanine level was 10.28±4.82. Seventy percent of our patients had MRI involvement, in whom 20% showed atrophic changes, in addition to white matter involvement. Based on modified Thompson scoring, the score for our study group was 4.84. The maximum involvement in MRI was in occipital region, followed by parietal, frontal, and temporal zones. There was not any correlation between MRI score and patients' age. But we found significant relationship between MRI score and the age of regimen cessation. No correlation was seen between phenylalanine level (at the time of Imaging) and MRI score. But there was a relationship between mean 1 year phenylalanine level and MRI score., Conclusion: According to the results of this study, brain MRI and white matter involvement can be used for evaluation of long-term control of phenylalanine level in PKU cases.

Objective: Toxic poisoning with methadone is common in children in Iran. Our study was carried out due to the changing pattern of methadone poisoning in recent years and increasing methadone toxicity., Materials & Methods: In this descriptive-sectional study, all of the methadone poisoned children younger than 12 years who were admitted to the Loghman Hakim Hospital in 2012, were assessed. Clinical symptoms and signs, para-clinical findings, and treatment were evaluated., Results: In this study, 16 boys and 15 girls who had been poisoned by methadone were enrolled. The mean age of patients was 55 months. All patients had been poisoned randomly or due to parent's mistakes. The mean time of symptoms onset after methadone consumption was 1 hour and 30 Min, indicating a relatively long time after onset of symptoms. Clinical findings were drowsiness (75%), miotic pupil (68 %), vomiting (61%), rapid shallow breathing (57%) and apnea (40%). In paraclinical tests, respiratory acidosis (69%) and leukocytosis (55.2%) were seen. The most important finding was increase in distance of QT in ECG (23.8%). The mean time of treatment with naloxone infusion was 51 hours. Three percent of patients had a return of symptoms after discontinuation of methadone. In patients with apnea, a longer course of treatment was required, and this difference was significant. Also, 17% of patients with apnea had aspiration pneumonia, which was statistically significant., Conclusion: We suggest long time treatment with naloxone and considering the probability of return of symptoms after discontinuation of methadone.

Objective: Biotinidase deficiency is one of the rare congenital metabolic disorders with autosomal recessive inheritance. If this disorder is diagnosed in newborn period, could be prevented well from mental and physical developmental delay and most of clinical manifestations., Materials & Methods: The patients were diagnosed as biotinidase deficiency in Neurology Department of Mofid Children's Hospital in Tehran, Iran, between 2009 and 2012 were included in this study. This study was conducted to define the age, gender, past medical history, developmental status, general appearance, clinical manifestations, neuroimaging findings, and response to treatment in 16 patients with biotinidase deficiency in this department., Results: In clinical presentation, cutaneous lesions were not found in 37% of the patients and 43% patients had not alopecia. 75% patients had abnormal neuroimaging that in 56% of them, generalized brain atrophy and myelination delay were found. Results of the present study showed the efficacy of biotin in early diagnosed patients with seizure and dermatological manifestations. The seizure and skin manifestations were improved after biotin therapy., Conclusion: According to the results of this study, we suggest that early assessment and diagnosis have an important role in the prevention of disease progression and clinical signs.

Objective: Methylmalonic acidemia is one of the inborn errors of metabolism resulting in the accumulation of acylcarnitine in blood and increased urinary methylmalonic acid excretion. This disorder can have symptoms, such as neurological and gastrointestinal manifestations, lethargy, and anorexia., Materials & Methods: The patients who were diagnosed as methylmalonic acidemia in the Neurology Department of Mofid Children's Hospital in Tehran, Iran, between 2002 and 2012 were included in our study. The disorder was confirmed by clinical findings, neuroimaging findings, and neurometabolic and genetic assessment in reference laboratory in Germany. We assessed the age, gender, past medical history, developmental status, clinical manifestations, and neuroimaging findings of 20 patients with methylmalonic acidemia., Results: Eighty percent of the patients were offspring of consanguineous marriages. Half of the patients had Failure to thrive (FTT) due to anorexia; 85% had history of developmental delay or regression, and 20% had refractory seizure, which all of them were controlled. The patients with methylmalonic acidemia were followed for approximately 5 years and the follow-up showed that the patients with early diagnosis had a more favorable clinical response in growth index, refractory seizure, anorexia, and neurodevelopmental delay. Neuroimaging findings included brain atrophy, basal ganglia involvement (often in putamen), and periventricular leukomalacia., Conclusion: According to the results of this study, we suggest that early assessment and diagnosis have an important role in the prevention of disease progression and clinical signs.

Objective: Muscle biopsy is a very important diagnostic test in the investigation of a child with suspected neuromuscular disorder. The goal of this study was to review and evaluate pediatric muscle biopsies during a 2-year period with focus on histopathology diagnosis and correlations with other paraclinic studies., Materials & Methods: We investigated 100 muscle biopsies belonging to patients with clinical impression of neuromuscular disorder. These patients have been visited consecutively by pediatric neurologists during 2010 to 2012. Samples were investigated by standard enzyme histochemical and immunohistochemical techniques., Result: Sixty-nine (69%) males and 39 (39%) females with a mean age of 5.7 years were evaluated. Major pathologic diagnoses were Muscular dystrophy (48 cases), Neurogenic atrophy (18 cases), nonspecific myopathic atrophy (12cases), congenital myopathy (6 cases), storage myopathies (4 cases) and in 6 cases there was no specific histochemical pathologic finding. EMG was abnormal in 79 cases. Degree of correlation between EMG and biopsy result was significant in children ≥ 2 years of age., Conclusion: This study confirms the high diagnostic yields of muscle biopsy especially only if standard and new techniques such as enzyme study and immunohistochemistry are implemented. Also, we report 11 cases of Merosin negative congenital muscular dystrophy. This is the largest documented case series of Merosin deficient congenital muscular dystrophy reported from Iran.