Congenital absence of the mammillary bodies: a novel finding in a well-studied case of developmental amnesia.

Individuals with developmental amnesia experience compromised development of episodic memory for details of personal life events, believed to relate to changes to the hippocampus after birth. Here we report the very rare discovery of aplasia of the mammillary bodies, hypogenesis of the fornix, and abnormal hippocampal shape and orientation in H.C., a well-documented case of selectively compromised episodic memory development who is the subject of numerous published empirical articles. These anatomical abnormalities are highly suggestive of disrupted extended hippocampal system development very early in gestation, despite an original diagnosis of developmental amnesia and assumed perinatal hypoxia. These findings provide a unique window into the normal function of the mammillary bodies, fornices, and related anterior nuclei of the thalamus bilaterally. The results also encourage re-examination of the pathological basis of developmental amnesia in other cases reported in the literature.

A case of Ohtahara syndrome with olivary-dentate dysplasia and agenesis of mamillary bodies.

We report a patient with early infantile epileptic encephalopathy (EIEE) with suppression-burst (Ohtahara syndrome) associated with olivary-dentate dysplasia and agenesis of mamillary bodies is reported. Although those with Ohtahara syndrome are a heterogeneous group, virtually all reported cases are secondary to neuronal migrational disorders, sometimes only identified by detailed neuropathologic examination, as in this case report, which describes mamillary body agenesis as a not-yet-recognized anomaly associated with Ohtahara syndrome. All children with Ohtahara syndrome should have high-resolution magnetic resonance imaging (MRI) and detailed postmortem neuropathologic examinations.

Fkh5-deficient mice show dysgenesis in the caudal midbrain and hypothalamic mammillary body.

The murine winged helix gene Fkh5 is specifically expressed in the developing central nervous system (CNS). Early embryonic Fkh5 expression is restricted to the mammiliary body region of the caudal hypothalamus, midbrain, hindbrain and spinal cord. Postnatally, signals persist in specific nuclei of the mammillary body and in the midbrain. We generated Fkh5 deficient mice by homologous recombination to assess its in vivo function. At birth, Fkh5-deficient mice are viable and indistinguishable from wild-type and Fkh5 heterozygous littermates. However, about one third die within the first two days and another fifth before weaning. Surviving Fkh5-deficient mice become growth retarded within the first week and remain smaller throughout their whole life span. Fkh5-deficient females on 129Sv x C57BL/6 genetic background are fertile, but do not nurture their pups. More detailed analysis of Fkh5-deficient brains reveals distinct alterations in the CNS. In the midbrain, mutant mice exhibit reduced inferior colliculi and an overgrown anterior cerebellum. Furthermore, the hypothalamic mammillary body of Fkh5-deficient brains lacks the medial mammillary nucleus. These results suggest that Fkh5 plays a major role during CNS development.

Asymmetric mamillary bodies: MR identification.

We report three cases in which there was marked asymmetry of the mamillary bodies, noted on MR in two and at autopsy in the third. Based on its proposed pathogenesis, we suggest that this finding could have value in locating temporal lobe disease in patients with intractable epilepsy.

Mammillo-hypophyseal duplication (diplo-mammillo-hypophysis).

A first-time description is given of a unique combination of congenital deformities encountered in a female infant born in the 35th week of gestation and surviving for minutes only. The principal malformations comprised duplicity of the hypophysis cerebri and mammillary bodies, olfactory aplasia, agenesis of corpus callosum, Dandy-Walker syndrome, thoracolumbo-sacral rachischisis and hydromyelia, associated with palato-gnatho-cheilo-schisis, defects in the pericardium and cardiac interventricular septum and gross maldevelopment of the diaphragm. Of these cerebral anomalies, we have chosen to concentrate on the condition which we denominate "diplo-mammillo-hypophysis" (mammillo-hypophyseal duplication) as the object of this study. On grounds of embryonal development it is considered to have come about during the first half of the 2nd month of gestation. The likely genesis of the pathologic findings is discussed.

Partial fusion of the mamillary bodies. Case study and review of congenital anomalies of these structures.

We present an anatomopathologic study of a case of partial fusion of the mamillary bodies in a 57-year-old man with no neurologic or neuropsychiatric change. Medial nuclei were fused. Remaining nuclei and afferent and efferent connections were preserved. The comparison of this case with other similar malformations suggests the possibility of disturbances in certain morphogenetic phases of these structures.

[Supernumerary mammillary bodies--findings in a case of fetal alcohol syndrome]. / Uberzählige corpora mammillaria--ein Befund bei einem Fall mit fetalem Alkoholsyndrom.

A case of fetal alcohol syndrome is described, in which supernumerary corpora mamillaria were found and in which the exterior embryonal-cell granular layer of the cerebellum showed superficial indentations.