A case of cerebral hypoplasia/dysplasia detected at autopsy

Summary

Presented case was a 2–year-old baby girl who had been treated for nearly one year with the indication of multifocal epileptiform anomaly. She was found dead in her bed in morning hours, autopsy was planned after prosecutors investigation. On internal autopsy examination, shrinkage of gyral structures in the frontal, and parietal lobes of the left hemisphere, markedly enlarged sulci, and a hypoplastic appearance were noted. Histopathological examination revealed evidence of pneumonia, brain exposed microgyral formations, disordered cortical stratification, hypercellularity, dysmorphic neuronal structures, balloon cells with diagnosis of cortical dysplasia. Pneumonia was reported as a cause of death. We aimed to discuss in the light of the literature a case with cerebral hypoplasia which is rarely seen at forensic autopsies.

Keywords:
cerebral hypoplasia/dysplasia – autopsy – congenital malformation – sudden death.

Though limited information is available about the cortical developmental malformation, these types of malformations are known to be among important causes of mental-motor retardation, epilepsy, and other neurological disorders. Owing to sophisticated neuroradiological methods, it is more frequently detected (1-8). Although its underlying pathological etiologies are not completely known, it has been evaluated as a cerebral response to genetic, and environmental factors. Besides many factors in pregnancy are known to effect migration of neuroblasts, and genetic origins of many neuronal migration disorders have been also indicated in the literature (1-3).

CASE REPORT

As we learnt from her family, our case was a 2 –year-old baby girl who had been treated for nearly one year with the indication of multifocal epileptiform anomaly, and his physical activity slowed down with age, and she could hardly hold her head at erect position. Besides she couldn’t move her lower part of her body by herself , and suffered from frequent convulsive seizures. Her family was a housekeeper of a farmhouse, and she was found dead in her bed in the morning hours by her grandmother. The prosecutor requested autopsy to determine the precise cause of her death. On her autopsy, external physical examination of the corpse performed in Bursa Morgue Department could not reveal any traumatic lesion except for an ecchymotic area on the lateral part, and upper eyelid of her right eye of this baby girl who was 90 cm in height, and 10 kg in weight. On internal examination, her brain (569 gr), heart (76 gr), right lung (134 gr), left lungs (120 gr), and liver (569 gr) were weighed. On cerebral dissection, macroscopic differences were detected between cerebral hemispheres. Shrinkage of gyral structures in the frontal, and parietal lobes of the left hemisphere, markedly enlarged sulci, and a hypoplastic appearance relative to the contralateral hemisphere were observed (Fig. 1). In the same region, markedly enlarged meningeal capillaries, and congestion were detected. Mottled appearance of the lungs, signs of congestion in the heart, and kidneys, and fatty liver were also observed. On histopathological examination, microgyral formations, increase in the number of   meningeal capillaries, disordered cortical stratification, hypercellularity, dysmorphic neuronal structures, balloon cells, and cortical dysplasia were detected (Fig. 2). Mottled appearance of the lungs, infiltration of neutrophilic leukocytes within alveoli, and brochial lumens, signs of edema, congestion, and pneumonia were detected. Chemical analyses revealed the presence of therapeutic doses of antiinflammatory paracetamol (126 ng/mL), and antiepileptic valproic acid (2526 ng/mL) in blood which were excreted in urine. On systematic biochemical analyses, any other toxic material was not detected in blood, and urine samples. Cause of death of this baby with the diagnosis of congenital multifocal epileptiform anomaly was reported as pneumonia. Herein, we intended to discuss hypoplastic-dysplastic cerebral anomaly which is rarely seen in forrensic autopsies in the light of the literature findings.

DISCUSSION

Though limited information is available about the frequency, and causes of cortical developmental malformations of the brain , these types of malformations are among important causes of mental-motor retardation, epilepsy, and other neurological disorders (1-8). Epilepsy, motor- mental retardation, and focal neurological problems are the most important clinical presentations as is in our case. Besides epileptiform seizures with partial, and generalized attacks have been reported (1-4). Similar to our case, Fauser et al.(5) emphasized that despite antiepileptic treatment, history of epileptiform seizures can be detected. They also indicated that in some cases these epileptic seizures can not become manifest   for years, and also demonstrate resistance against certain antiepileptic drugs which are predominantly seen in cases with cytoarchitectural abnormalitities. In the developmental anomalies of the brain, symptoms in a wide spectrum have been reported on macroscopic examinations, while some authors also indicated the presence of hypoplastic lesions, and asymmetries in cerebral lobes (1,2,3,6). Cortical dysplasias of the brain were firstly defined by Taylor, and Falconer in the early 1970s (6,7). Nowadays, as for neuropathological, and clinical features, non-Taylor-types of focal cortical dysplasia have architectural, and cytoarchitectural subtypes, while Taylor-type cortical dysplasia is categorized as subtypes with or without balloon cells.Generally three main subtypes of cortical dysplasia have been defined. In neuropathological classifications of cortical dysplasias, in the presence of dysplastic cytorarchitecture, cortical laminar disarrangement, dysmorphic neurons, and giant balloon cells have been detected (6,7). Microscopic examination of our case revealed microgyral formations, increase in meningeal capillaries, and also characteristic histopathological findings of cortical dysplasia including disordered cortical stratification, hypercellularity, balloon-type cells. Despite some attempts at categorization of cortical dysplasias based on the presence of certain microtubule-associated proteins, and genes effective on migration, irrefutable conclusions which might lead to detailed classification of cortical dysplasias have not been suggested up to now (3,8). It has been also emphasized that among radiological modalities, cerebral MR might reveal some characteristic differences between Taylor-, and non-Taylor type dysplasias which might also have a favourable effect on organization of preoperative planning. The researchers also underlined some potential differences between surgical treatments of Taylor, and non-Taylor type cortical dysplasias (7,8). Rapid advances in biological, and imaging techniques increase our knowledge about cerebral cortical dysplaisas (6). However, as is revealed in our case, necroptic examinations have proved that especially in pediatric cases histopathological analysis of cerebral specimens should be more carefully conducted, and also evidenced that autopsy examinations is helpful in detailed comprehension, and precise classification of cerebral malformations.

Correspondence address:

Bülent Eren, M.D.

Council of Forensic Medicine of Turkey

Bursa Morgue Department;16010, Bursa, Turkey.

tel.: +90 224 222 03 47; fax: +090 224 225 51 70

e-mail: drbulenteren@gmail.com