PORENCEPHALY LOCATED IN THE MCA TERRITORY

ABSTRACT:

Infant with evident neurological symptomatology suggesting a left cerebral hemisphere lesion came to the Neurology Clinic to establish the diagnosis. The imagistic exam confirms the presence of neurological symptomatology suggesting not only an encephalomalacia of the left cerebral hemisphere, but also 2 (two) lesions of porencephaly at the level of left cerebral hemisphere. The aspect of the cerebral lesions, their position (unilaterality) and their extension, corroborated with the cerebral vascular territories schemes, indicate an ischemic lesion involving the middle cerebral artery (MCA) territory.

INTRODUCTION

Porencephaly is a type of cephalic disorder involving encephalomalacia.This is an extremely rare disorderof the central nervous system in which a cyst or cavityfilled with cerebrospinal fluid develop in the brain (1).

Children with porencephaly may have poor or absent speech development, epilepsy, hydrocephalus,spastics contractures and mental retardation (2).

Diagnosis is usually made before the infant reaches his or her first birthday (2). Antenatally, the diagnosis is performed with ultrasound and postnatally may be confirmed by CT or MRI (2).

The prognosis for children with porencephaly varies according to the location and the extend of the cysts and cavities. Some children with this disorder develop only minor neurological problems and have normal intelligence, while others may be severely disabled and die before their second decade of life (2).

CASE PRESENTATION

Anamnesis and clinic findings 

After the age of 7 months, the infant has repeatedly come to the neurologist because of motor retardation of the right upper limb and spasm crisis during fl exion.

He has been hospitalized with the diagnosis of Westsyndrome, right upper limb monoparesis and porencephaly at the Infantile Neuropsychiatry Clinic of theEmergency Children’s Hospital from Timisoara.

Paraclinic findings 

 EEG – slow polymorphic delta theta in left TP.Imagical aspect (only one exam from 2003; after 2003, the patient was lost from our supervision):
IRM – vast cerebral lesion, encephalomalacia type, at the left cerebral hemisphere level that aff ects frontal,parietal and temporal lobe and tho aspects of porencephaly – one having large size (6 cm/2,5 cm) located on the frontal lobe on the touche fronto – parietal and the other of narrow dimensions located deeply on the left justaventricular level.The left ventricle and the left subarachnoid space are moderately increased.Without pathological contrast enhancement. Th e angioIRM was not performed (exam from 2003).

DISSCUSIONS

Porencephaly is, usually, the result of damage from stroke or infection, but it can also be caused by abnormal development before birth (wich is inherited and less common) (2).

As human malformation, most authors recognize two major sub groups (of porencephaly), based on both pathologic findings and etiologic hypothese: type 1 or encephaloclastic porencephaly (EP),and type 2 or development porencephaly (DP), withlatter being subdivided into schizencephaly and simple porencephaly (SP)(3)(4).

Cerebral hemorrhage is a well documentated cause of EP. The authors have provided very suggestive evidence of an association between inherited thrombophilia variants and encephaloclastic porencephaly (EP)(3).

Two thirds of children (age 0 – 18 years) in one study had at least 1 of the prothrombotic risk factors tested, and several children had multiple risk factors tested. Prothrombotic abnormalities are common among children with AIS or porencephaly (5).

The authors have reported ultrasound and magneticresonance imaging (MRI) findings in a fetus with intracranial hemorrhage and porencephaly, secondary tointrauterine cytomegalovirus (CMV) infections (6).

Maternal abdominal trauma is the cause of the malformations through hemorrhage or hypoperfusion, and a case of encephaloclastic porencephaly (EP) following serious maternal abdominal trauma has been reported (7).

In a report of 10 pregnancies with CNS anomalies associated with in utero exposure to vasoactive drugs (predominantly cocaine), there was three with typical encephaloclastic porencephaly (EP) and one with a severe simple porencephaly (SP) (7).

The aspects of the lesions in our case (vast encephalomalacia with porencephaly), the unilaterality of the lesions and the fact that they were occupying the MCA territory determined us to indicate a perinatal ischemic (vascular) cause (cerebral ramolisment). Th e porencephaly situated deeply (justaventricular) indicate an ischemic (vascular) cause too, in the choroidal arteries territory.

Porencephaly results from infarction in the territoryof a major artery, usually the middle cerebral artery (8).

An infarct, that occurs during the antenatal or early postnatal period and acts in isolation, is a relatively rare cause of brain damage (8).Almost 90% are unilateral and in 83% the infarct is in the distribution of the middle cerebral artery (8).

It is presumed to be the result of embolization arising from placental infarcts or of thrombosis caused byvascular maldevelopment or sepsis (8).

Axial section throught superior level cerebral hemispheres, at superior level lateral ventricles and the section (scheme) with cerebral vascular territories –Fig. 1 (9).

Axial section throught middle level cerebral hemispheres at the middle level diencephalon and the section (scheme) with vascular cerebral territories – Fig. 2. (10).

Fig. 1. Axial section throught superior level cerebral hemispheres, at superior level lateral ventricles

Fig. 2.Axial section throught middle level cerebral hemispheres at the middle level diencephalon

37 – anterior cerebral artery territory, 38 – posterior communicating artery territory, 39 – middle cerebral artery territory, 41 – choroidal arteries territory, 42 – posterior cerebral artery territory.

Axial section throught inferior level of cerebral hemispheres and the section (scheme) with vascular cerebral territories – Fig. 3 (10).
Coronal section throught third ventricle and the section (scheme) with vascular cerebral territories – Fig. 4 (11).

Fig. 3. Secţiune axială prin nivelul inferior al emisferelor cerebrale

38 – anterior cerebral artery territory, 39 – posterior communicating artery territory, 40 – posterior cerebral artery, perforating branches territory, 41 – choroidal artered territory, middle cerebral artery tewrritory, posterior cerebral artery, posterior choroidal branches territory

Fig. 4. Coronal section throught third ventricle and the section

CONCLUSIONS

1. The cerebral vascular territories schemes represent a key element in establishing the right diagnosis regarding the cerebral lesions.
2. The cerebral lesions aspects, their position (unilaterality) and their extension (signifi cantly extended on three lobes: frontal, parietal and temporal) corroborated with the cerebral vascular territories schemes indicate, as the major lesion, an ischemic lesion in the middle cerebral artery (MCA) territory.

BIBLIOGRAPHY:

1. Porencephaly – Wikipedia, the free encyclopedia, http://en.wikipedia.org/wiki/Porencephaly
2. Cleveland Clinic – Porencephaly, 07/2010, sources: National Organization for Rare Disorders (NORD), National Institute of Health and National Institute of Neurological Disorder and Stroke
3. Roger E. Stevenson, Judith G. Hall – Human malformations and related anomalies, Edition 2, Oxford University Press, 2006.
4. Tiziana Granata, Giorgio Battaglia, Harvey B. Sarnat – Porencephaly, Clinical Summary, Neurology – MedLink,December 19, 2009.
5. Lynch JK, Han CJ, Nee LE – Prothrombotic Factors in Children with Stroke or Porencephaly , Pediatrics, vol. 116,447 – 457, 2005.
6. Asif Moinuddin, Robert C. Mc. Kinstry, Kimberly A. Martin, Jeffry J. Neil – Intracranial hemorrhage progressing to porencephaly as a result of acquired cytomegavirus infection – an illustrative report, Prenatal Diagnosis, Vol 23,pages 797
7. Malcolm I. Levene, Frank A. Chervenak – Neonatal Neurology and Neurosurgery, Fourth Edition, 2009.
8. John H. Menkes, Harvey B. Sarnat, Bernard L. Maria – Child Neurology, Seventh Edition, 2006.
9. James G. Smirniotopoulos – Cerebral vascular territories,2004.
10. Joseph Hanaway, Thomas A. Woolsey, Mokhtar H. Gado,Melville p. Roberts, Jr. – The Brain, A visual guide to the human central nervous system, Fizgerald Science Press, Inc.Maryland, 1998.
11. Cerebrovascular Territories, Neurovascular Pathology, Blumenfeld, Neuroanatomy through Clinical Cases, Sinauer,2002, pg. 368 – 384.