Age-related size reduction of foramina in the cribriform plate

Abstract

Anecdotal evidence suggests that the foramina of the cribriform plate which transmit cranial nerve I decrease in size with age, but this finding has never been supported with quantitative data. It has also been observed that olfactory function declines with increasing age. It has been hypothesized that the cribriform plate foramina closure may be responsible for the olfactory performance decrease with age. We gathered quantitative data to test an age-related decline in cribriform plate foramina area.We report data for the area of patent foramina in the posterior 1 cm of 57 cribriform plates from 40 skulls of known age and sex. Analyses were performed to test for the effects of age, sex, and lateralization on foramina area.The area of patent foramina in the cribriform plate decreases with increasing age. Age is a strong covariate with foramina area (P value ϭ 0.0025). The regression equation for the area of patent foramina is: expected area ϭ 8.17 Ϫ (0.06) age. Adding the variable sex does not contribute significantly (P value Ͼ 0.28) to the model which utilizes age alone. Nor was there any significant lateralization in patent foramina area.The area of patent foramina in the cribriform plate decreases with increasing age, and there is no significant difference between males and females or left and right sides. Such decreases in patent foramina may be associated with impaired olfactory function in the aged. Anat. Rec. 251:326-329, 1998. 1998 Key words: cribriform plate; olfaction; aging; sensory systemsThe cribriform plate of the ethmoid bone contains foramina which transmit nerve fila of cranial nerve I from the olfactory epithelium to the olfactory bulb. These fila are responsible for conveying olfactory stimuli from the nose to the brain. Krmpotic-Nemanic (1969) performed a qualitative analysis of foramina obstruction in the spiral tractus and vestibular area of the fundus of the inner ear and the cribriform plate in human cadaver specimens. This study indicated that older individuals have smaller foramina in these areas (Krmpotic-Nemanic, 1969). Obstruction of the foramina in the cribriform plate as well as in other cranial areas is due to appositional bone growth. Krmpotic-Nemanic (1969) also reported a decrease in number and, in some cases, an absence of nerve fibers in specimens with obstruction of the foramina. This suggests that the appositional bone growth may sever or block the nerve fibers passing their respective plates. Reports in which functional olfactory performance have been assessed have indicated a large decline in olfactory function with age, and it has been suggested that this olfactory decline in older individuals may be the result of obstructed foramina in the cribriform plate (Doty and Snow, 1988;Doty, 1989). In addition, these data reveal that males show a greater decrease in olfactory function than females (Doty and Snow, 1988;Doty, 1989).In the present report, we examine human cribriform plate foramina using quantitative measures to assess whether there are age-related changes,...

Normative Performance on the Brief Smell Identification Test (BSIT) in a Multi-Ethnic Bilingual Cohort: A Project FRONTIER Study1

“…In part, the relationship between aging and olfactory impairment has been attributed to degeneration of the olfactory bulb and olfactory epithelium (Bhatnagar, 1987; Duda et al, 1999), ossification of the olfactory foramina (Kalmey, Thewissen, Dluzen, 1998), and neuropathological changes connected with neurodegenerative diseases (Hawkes & Doty, 2009). Although progress has been made in understanding the relationship between aging and olfactory decline, more research is needed to further delineate the respective influences of peripheral versus cortically-based olfactory pathology on BSIT scores, as this differentiation is essential to ensuring valid clinical interpretations (Doty et al, 1984; Martzke et al, 1997).…”

Cranial Nerve Foramina Part I: A Review of the Anatomy and Pathology of Cranial Nerve Foramina of the Anterior and Middle Fossa

“…The total area of the perforations is age-dependent; it is 3.79 - 3.99 mm 2 in those over 50 years old and 5.61 - 7.91 mm 2 in those under 50. This decrease in the area over time, causing compression and dysfunction of the olfactory nerves, is thought to explain the decreased olfactory sensation in the elderly [41]. …”

The olfactory vector hypothesis of neurodegenerative disease: Is it viable?

“…Finally, aside from the possibility of multiple causes, the olfactory vector hypothesis is not disproved by a single case report of a woman with an imperforate cribriform plate who exhibited AD-related pathological lesions. Because the foramina of the cribriform plate close off from appositional bone growth in a significant number of people as they age, 64 a pathogenic agent could have entered the brain via the olfactory fila before such occlusion.…”