Rostral cranial fossa as a site for cerebrospinal fluid drainage - volumetric studies in dog breeds of different size and morphotype.

BACKGROUND: Hydrocephalus is a multifactorial condition, whose aetiology is not fully understood. Congenital hydrocephalus frequently occurs in small and brachycephalic dog breeds. Although it is widely accepted that the cribriform plate located in the rostral cranial fossa (RCF) is a site of cerebrospinal fluid (CSF) drainage, the RCF has not been studied extensively. Literature reports indicate that a decreased caudal cranial fossa (CCF) volume in the course of the Chiari-like malformation may obstruct CSF circulation. We hypothesised that morphological diversity among different breeds in the volume of the RCF may affect CSF circulation. The aim of the study was to carry out a volumetric analysis of the RCF and the cranial cavity and to determine the ratio between them in dog breeds of different size and morphotype. We performed computed tomography (CT) morphometric analysis of the RCF compartment by obtaining volume measurements from the transverse and reformatted sagittal and dorsal planes. RESULTS: The rostral cranial fossa percentage - volume of the rostral cranial fossa/volume of cranial cavity × 100 (volRCF/volCC × 100) was lower in small and brachycephalic dog breeds than in the other dogs. CONCLUSIONS: A reduced RCF volume was detected in small and brachycephalic dog breeds, some of which are predisposed to congenital hydrocephalus. This may lead to overcrowding of brain parenchyma in the RCF and may impede CSF circulation. Our observations may be useful for future studies focusing on the causes and new therapies to treat conditions such as hydrocephalus and syringomyelia.

MR cisternography/myelography of post-traumatic spinal CSF fistulae and meningeal lesions in small animals.

BACKGROUND: The diagnosis of post-traumatic spinal cerebrospinal fluid (CSF) fistulae due to dural tears or lesions remains a challenge. Thus far, CT myelography is the standard test used to diagnose these complications. PURPOSE: To evaluate the diagnostic ability of gadolinium-enhanced MR cisternography/myelography (intrathecal gadopentate dimeglumine or Gd-DTPA) in small animals that had experienced accidental spinal trauma. MATERIAL AND METHODS: Four dogs and one cat suffered traumatic accidents resulting in neurological deficits underwent spinal MRI with intrathecal Gd-DTPA after routine plain films and MR images. RESULTS: T2-weighted SE images showed high water content in the epidural space or in the surroundings of the vertebrae in four animals. MR myelography revealed CSF leakage in all of them. In two animals CSF leaks were observed exuding from the spinal canal and tracking towards adjacent loose fat and interfascial planes. In two other animals Gd-DTPA extravasation was diffusely collected in paraspinal tissues around the vertebral arch. In the fifth animal a focal pseudomeningocele was observed adjacent to the traumatized region. CONCLUSION: Intrathecal administration of Gd-DTPA is an effective method to reveal and confirm post-traumatic spinal CSF fistulae or other dural lesions in animals with potential application in humans.