Context: Morgagni-Stewart-Morel syndrome is defined as the presence of hyperostosis frontalis interna, variably associated with metabolic, endocrine, and neuropsychiatric disorders. The possible cause-effect relationship of these associations remains uncertain.
Case presentation: A 75-year-old woman presented with severe frontal headache and a history of psychotic disorders. On instrumental examination she was found to have extensive frontal hyperostosis and cortical atrophy. These findings, associated to the metabolic and neuropsychiatric pattern of the patient, are consistent with a high penetrance of Morgagni-Stewart-Morel syndrome.
Evidence acquisition and synthesis: In this clinical case seminar, we summarize the current understanding of the association between hyperostosis frontalis interna and Morgagni-Stewart-Morel, based on a MEDLINE search (case reports, original articles, and reviews published between 1928 and 2011) on this topic. Possible pathophysiological mechanisms underlying both the headache and the hyperostosis frontalis interna are discussed.
Conclusion: A case of full penetrance of Morgagni-Stewart-Morel syndrome is reported, presenting many of the clinical features described in the literature. Metabolic and endocrine dysfunctions should be interpreted not only as isolated components of the syndrome, but also as the reason behind its pathogenesis. Endocrine or nutritional disorders may have led to an altered bone metabolism with frontal bone apposition. On the other hand, the severity of our patient's neurological and psychiatric symptoms correlates well with the severity of her hyperostosis frontalis interna and the cortical atrophy.