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LETTER TO EDITOR |
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Year : 2020 | Volume
: 68
| Issue : 4 | Page : 941-942 |
Hypoxic Ischemic Encephalopathy or Metabolic Etiology—MRI as a Clue to Diagnosis
Ranjana Mishra1, Jyotsna Verma1, Swapnil Sheth2, IC Verma1, Ratna Dua Puri1
1 Department of Medical Genetics and Genomics, Institute of Medical Genetics and Genomics, Rajinder Nagar, New Delhi, India 2 Department of Radiology, Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi, India
Date of Web Publication | 26-Aug-2020 |
Correspondence Address: Dr. Ratna Dua Puri Chairperson and Senior Consultant, Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi - 110 060 India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0028-3886.293478
How to cite this article: Mishra R, Verma J, Sheth S, Verma I C, Puri RD. Hypoxic Ischemic Encephalopathy or Metabolic Etiology—MRI as a Clue to Diagnosis. Neurol India 2020;68:941-2 |
Sir,
Molybdenum cofactor deficiency (MOCD) is a life-threatening, pan-ethnic, rare autosomal recessive disorder. We report a 6-month-old girl with infantile onset intractable seizures, severe psychomotor retardation, and a similarly affected male sibling. Characteristic dysmorphism included microcephaly, dolicocephaly, prominent sagittal and metopic sutures, deep-set eyes, puffy cheeks, and gum hypertrophy. There was axial hypotonia, appendicular hypertonia, scissoring of lower limbs, and hyperreflexia. A previously performed cranial computed tomography reported hypoxic ischemic encephalopathy (HIE). MRI brain showed severe cystic encephalomalacic changes involving the fronto- parietal region, atrophy of bilateral basal ganglia, chronic lacunar infarct in bilateral thalami, dysgenetic corpus callosum, and brainstem atrophy with flattening of the pons [Figure 1] and [Figure 2]. The significant cerebral volume loss was unusual for HIE at this age and was suggestive of MOCD or isolated sulfite-oxidase deficiency (ISUOD). The urine metabolic screen for sulfite oxidase deficiency was negative. If this test is done on a stored sample, it can be false negative as urinary sulfite is unstable. A repeat on a fresh urine sample was positive, suggesting ISUOD or MOCD. This was confirmed by demonstrating a S-Sulfocysteine peak in urine by quantitative ultra-performance liquid chromatography. Low uric acid levels and low homocysteine levels suggested MOCD over ISUOD. | Figure 1: T2W axial section at the level of basal ganglia - Cystic encephalomalacic changes in bilateral cerebral parenchyma and atrophy of bilateral basal ganglia with chronic lacunar infarctions (white arrow) in bilateral thalami (Right thalamic infarct is not shown in this image) (a); axial T2W sections of brain showing ventriculomegaly and diffuse cystic encephalomalacia changes in bilateral fronto parietal white matter. Focal pachygyria is also seen in bilateral frontal region (yellow arrows) along with subdural hygroma in right fronto-parietal & left occipital region (bold white arrow) (b)
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 | Figure 2: Axial susceptibility weighted images showing multiple foci of blooming suggestive of micro bleeds (blue arrow) (a). Hemosiderine staining is seen around the bilateral fronto-parietal subdural collection (dotted orange arrow); T2W sagittal image showing brainstem atrophy in the form of flattening of the pons (white arrow). In addition, dysgenetic, thinned out and hyperintense corpus callosum is seen. (dotted black arrow) (b)
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Neuroimaging features of diffuse encephalomalacia with involvement of basal ganglia and thalami, and particularly the subcortical cysts in an infant with refractory seizures, are suggestive of MOCD rather than HIE.[1] This characteristic MRI phenotype was present in the patient and served as the first clue to diagnosis.
Molecular testing confirmed a previously reported,[2] homozygous pathogenic mutation- c.45T>A in the MOCS2 gene, consistent with a diagnosis of MOCD type B. There is only one reported case of a prenatal ultrasound at 35 weeks' gestation that revealed multiple subcortical cavities, ventriculomegaly, dysgenetic corpus callosum, hypoplastic cerebellum, and an enlarged cisterna magna, in a patient of MOCD.[3] Therapy with cyclic pyranopterin monophosphate for type A MOCD is available for patients diagnosed early.[4]
MOCD carries a poor prognosis and if a mutation is identified in the proband, a prenatal diagnosis can be offered at 11 weeks of gestation.
In conclusion, MOCD must be considered in all infants with microcephaly, facial dysmorphism, and refractory seizures. A urine sulfite dipstick test is recommended in such cases which can be corroborated with a low uric acid level. Also, genotyping helps prevention of recurrence by prenatal diagnosis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
» References | |  |
1. | Topcu M, Coskun T, Haliloglu G, Saatci I. Molybdenum cofactor deficiency: Report of three cases presenting as hypoxic–ischemic encephalopathy. J Child Neurol 2001;16:264-70. |
2. | Reiss J, Johnson JL. Mutations in the molybdenum cofactor biosynthetic genes MOCS1, MOCS2, and GEPH. Hum Mutat 2003;21:569-76. |
3. | Carmi-Nawi N, Malinger G, Mandel H, Ichida K, Lerman-Sagie T, Lev D. Prenatal brain disruption in molybdenum cofactor deficiency. J Child Neurol 2011;4:460-4. |
4. | Hitzert MM, Bos AF, Bergman KA, Veldman A, Schwarz G, Santamaria-Araujo JA, et al. Favorable outcome in a newborn with molybdenum cofactor type A deficiency treated with cPMP. Pediatrics 2012;130:e1005-10. |
[Figure 1], [Figure 2]
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