Comparative Cross Sectional Prospective Study of Anterior Skull Base Thickness in Spontaneous Cerebrospinal Fluid Rhinorrhoea vs Matched Controls.

Cerebrospinal fluid (Csf) leak is the leakage of CSF from subarachnoid space into the nasal cavity.Csf rhinorrhoea is classified as traumatic and non traumatic causes (Ommaya et al. J Neurol Neurosurg Psychiatry 31(3):214, 1968). Spontaneous csf leaks occur due to increased intracranial pressure. Early diagnosis of spontaneous csf leaks may prevent complications like meningitis. This was a cross sectional prospective study done in a tertiary care hospital. Group A-spontaneous csf leak patients and Group B- Non csf leak matched controls. The anterior skull base thickness from fovea ethmoidalis, cribriform plate and lateral lamella were compared between the groups using high resolution computed tomography of paranasal sinus with 2 mm cuts. The anterior skull base thickness was measured by a senior radiologist in our tertiary centre. In this study, total of forty six patients were included, twentythree in each group. The Mean age in Group A and Group B was 48.95 and 48.78 respectively. Body mass index (BMI) was compared between the two groupsand spontaneous csf leak patients had higher value than non csf leak controls. The mean anterior skull base thickness of Group A (cribriform plate-0.56 mm, lateral lamella-0.66 mm, Fovea ethmoidalis-0.91 mm) was lower than Group B (cribriform plate-0.86 mm, lateral lamella-0.84 mm, Fovea ethmoidalis-0.97 mm) which was statistically significant ( value-< 0.05).