Alice in wonderland syndrome "through the looking-glass" in a rare presentation of non-convulsive status epilepticus in cerebral venous sinus thrombosis and COVID-19.

Alice in Wonderland Syndrome (AIWS) is a rare perceptual disorder, rarely associated with epileptic etiology. We report the case of a 23-year-old man with subacute onset of right peri-orbital headache and visual misperceptions consistent with AIWS Type B, who underwent laboratory tests, brain CT with venography, ophthalmic examination, and neurological assessment that turned out to be normal except for visuospatial difficulties and constructional apraxia. A nasopharyngeal SARS-CoV2 swab taken as screening protocol was positive. The EEG performed because of the persistence of AIWS showed a focal right temporo-occipital non-convulsive status epilepticus; a slow resolution of clinical and EEG alterations was achieved with anti-seizure medications. Brain MRI showed right cortical temporo-occipital signal abnormalities consistent with peri-ictal changes and post-contrast T1 revealed a superior sagittal sinus thrombosis, thus anticoagulant therapy was initiated. AIWS is associated with temporo-parieto-occipital carrefour abnormalities, where visual and somatosensory inputs are integrated to generate the representation of body schema. In this patient, AIWS is caused by temporo-occipital status epilepticus without anatomical and electroencephalographic involvement of the parietal region, consistent with the absence of somatosensory symptoms of the syndrome. Status epilepticus can be the presenting symptom of cerebral venous sinus thrombosis (CVST) which, in this case, is possibly due to the hypercoagulable state associated with COVID-19.

High-field magnetic resonance imaging investigation of distal border fragments of the navicular bone in horses with foot pain.

REASONS FOR PERFORMING STUDY: Distal border fragments of the navicular bone can be seen in lame and nonlame horses and their clinical significance remains open to debate. OBJECTIVES: To describe the magnetic resonance imaging (MRI) appearance of distal border fragments and the adjacent navicular bone. To investigate the relationship between fragments and other abnormalities of the navicular bone and the distal sesamoidean impar ligament (DSIL). METHODS: Horses were included if pain causing forelimb lameness was localised to the foot and high-field MR images were acquired. The size and location of distal border fragments were recorded. Abnormalities in the adjacent navicular bone were graded to obtain a fragment grade. A total navicular bone grade was assigned. The DSIL was also graded. A Chi-squared test was used to test for associations between the presence of a fragment and specific lesions involving the distal border of the navicular bone, the total grade of the navicular bone, and the grade of the DSIL. RESULTS: 427 horses were included and 111 fragments observed. There was a significant association between the presence of a fragment and the total navicular bone grade, osseous cyst-like lesions, increased number and size of the synovial invaginations of the distal border, increased signal intensity on fat suppressed images and size of distal border entheseophytes. CONCLUSIONS: There is an association between distal border fragments and other pathological MRI abnormalities of the navicular bone. POTENTIAL RELEVANCE: Distal border fragments are part of navicular disease, but their contribution to pain and lameness remains to be clarified.

Comparison between radiological and magnetic resonance imaging lesions in the distal border of the navicular bone with particular reference to distal border fragments and osseous cyst-like lesions.

REASONS FOR PERFORMING STUDY: There are no data concerning the accuracy of conventional and computed or digital radiography for evaluation of the equine foot. OBJECTIVES: To compare conventional film-screen and computed radiography with magnetic resonance imaging (MRI) for detection of distal border fragments of the navicular bone; and to establish which type of fragment was more likely to be detected radiologically. METHODS: Horses were included if forelimb lameness was localised to the foot and both radiography and high-field MR images had been acquired. Horses were divided into 2 groups based on acquisition of conventional (Group A) or computed (Group B) radiographs. The presence of distal border fragments was recorded. From MR images, distal border fragments were graded based on their size and changes in signal intensity in the adjacent navicular bone. Sensitivity and specificity of conventional and computed radiography for detection of fragments were calculated using MRI as the gold standard. A Chi-squared test was used to test for associations between specific radiological and MRI findings in the distal border of the navicular bone. RESULTS: In Group A 46 and 18 fragments were identified on MR and radiographic images, respectively; in Group B 45 and 17 fragments were seen. There was no significant difference between computed and conventional radiography. Grades 4 and 5 fragments or large-sized fragments were identified most frequently; low-grade fragments were unlikely to be observed. There was a significant correlation between radiological and MRI abnormalities of the distal border of the navicular bone. CONCLUSIONS: Conventional and computed radiography had similar, rather low sensitivity for identification of distal border fragments of the navicular bone, but specificity was high. Large-sized and high-grade fragments were most likely to be identified radiologically. POTENTIAL RELEVANCE: Fragments observed radiologically are likely to be associated with other pathological abnormalities of the distal border of the navicular bone.

Hind foot lameness: results of magnetic resonance imaging in 38 horses (2001-2011).

REASONS FOR PERFORMING STUDY: The distribution of lesions detected using magnetic resonance imaging (MRI) of hind feet has not been reported. OBJECTIVE: To evaluate type and distribution of lesions detected using MRI in hind feet of lame horses and to compare the findings with those reported in front feet; to document follow-up information. METHODS: Horses were selected if hindlimb lameness was abolished by plantar nerve blocks performed at the base of the proximal sesamoid bones. Magnetic resonance images were acquired using either a low-field or a high-field magnet, and all images were evaluated retrospectively by both authors. A primary diagnosis was defined as the most likely cause of lameness, based also on clinical findings and results of other imaging techniques. If ≥3 structures were equally affected, the horse was classified as having multiple injuries. Follow-up information was collected by telephone questionnaire; outcome was classified as return to former level of athletic function, working at a lower level or retired. RESULTS: Thirty-eight horses were included. Primary collateral sesamoidean ligament (CSL) injury was identified in 9 horses. Nine horses had multiple injuries, 8 had primary bone pathology, 5 had collateral desmopathy of the distal interphalangeal joint, one had primary deep digital flexor tendonitis, 2 had navicular bone pathology and 4 had lesions involving other structures within the foot. Seven horses were subjected to euthanasia shortly after diagnosis; 6 as a result of poor prognosis and one as a result of post anaesthetic complications, 4 of which had primary bone lesions, 2 multiple lesions and one distal interphalangeal joint pathology. Follow-up information was available for 24 horses. Eleven horses returned to previous performance and 2 to a lower level of performance; 9 horses were retired because of recurrent lameness. Five of 8 horses with CSL injury returned to previous performance and 2 to a lower level. CONCLUSIONS AND POTENTIAL RELEVANCE: Collateral sesamoidean ligament injury and primary bone pathology are commonly observed on MRI examination of hind feet, and the prognosis is reasonable.

Distal border fragments and shape of the navicular bone: radiological evaluation in lame horses and horses free from lameness.

REASONS FOR PERFORMING STUDY: The significance of distal border fragments of the navicular bone is not well understood. There are also no objective data about changes in thickness and proximal/distal extension of the palmar cortex of the navicular bone. OBJECTIVES: To describe the distribution of distal border fragments and their association with other radiological abnormalities of the navicular bone and describe the shape of the navicular bone in sound horses and horses with foot-related lameness, including navicular pathology. METHODS: Sound horses had radiographs acquired as part of a prepurchase examination. Lame horses had forelimb lameness abolished by palmar nerve blocks performed at the base of the proximal sesamoid bones. Diagnosis was assigned prospectively based on results of local analgesia and all imaging findings. The thickness of the palmar cortex of the navicular bone and size of proximal/distal extensions were measured objectively. Other radiological abnormalities were evaluated subjectively and each navicular bone graded. RESULTS: Fifty-five sound and 377 lame horses were included. All measurements were larger in lame compared with sound horses except the size of the distal extension of the palmar cortex. Fragments were observed in 3.6 and 8.7% of sound and lame horses respectively and in 24.1% of horses with a diagnosis of primary navicular pathology. There was an association between fragments and overall navicular bone grade, radiolucent areas at the angles of the distal border of the navicular bone and number and size of the synovial invaginations. CONCLUSIONS AND POTENTIAL RELEVANCE: The palmar cortex of the navicular bone was thicker in lame compared with sound horses. Distal border fragments were most frequent in horses with navicular pathology. Evaluation of changes in shape of the navicular bone may also be important for recognition of pathological abnormalities of the bone.

Topographic comparative study of paranasal sinuses in adult horses by computed tomography, sinuscopy, and sectional anatomy.

Clinical and radiographic investigations of paranasal sinuses in horses are difficult due to the complex anatomy of these regions, the lack of patognomonic symptoms, and the low sensitivity of conventional diagnostic techniques. The aim of this study was to produce an anatomical atlas to support computed tomography (CT) and sinuscopy of the paranasal sinuses of the adult horse. Transverse, sagittal, and dorsal CT images were acquired, and sinuscopy with both rigid and flexible endoscopes was performed. The heads were frozen and sectioned using a band saw, with the cuts aligned as close as possible with the CT transverse slices. Each CT image was compared with its corresponding anatomical section and sinuscopy image to assist in the accurate identification of specific structures.