French Bulldog Diagnosed With a Suspected Brain Tumor Shortly After Treatment for Spinal Arachnoid Diverticulum

An 8-year- and 8-month-old spayed female 8.8-kg French bulldog presented with a 4-month history of progressive deterioration, followed by paresis of both pelvic limbs. Orthopedic examination revealed no abnormalities. Neurological examination revealed no findings suggestive of brain dysfunction. However, abnormal findings, including impaired conscious proprioception in both pelvic limbs and hyperreflexia of patellar, cranial tibialis, and gastrocnemius reflexes, suggested a spinal segmental lesion in the T3-L3 region. The dog was diagnosed with a spinal arachnoid diverticulum in the T11-T12 vertebrae (Day 1) by magnetic resonance imaging (MRI) and underwent surgical treatment (dorsal laminectomy with dural marsupialization) on Day 27. The dog was presented to the referral hospital on a weekly basis and underwent neurological examinations at each visit. Initial neurological signs included persistent bilateral pelvic limb proprioceptive deficits; no other new neurological abnormalities were noted. Epileptic seizures occurred on Days 43 and 57. Brain MRI performed on Day 91 revealed findings suggestive of a glioma. The dog was administered prednisone (0.5 mg/kg SID, PO) and zonisamide (5 mg/kg BID, PO). Neurological abnormalities, such as circling and left forelimb ambulatory monoparesis, became more noticeable. The dog developed status epilepticus and died on Day 209. The owner said that the frequency of seizures was approximately twice a month and had not increased, and seizure duration did not appear to have lengthened until Day 209. In this case, no direct history or neurological abnormalities suggestive of a lesion in the forebrain region were noted until the onset of epileptic seizures; however, the glioma was diagnosed within 3 months of spinal arachnoid diverticulum diagnosis. Therefore, the brain tumor might have been detected if a brain MRI had been performed when spinal cord disease was initially diagnosed. This report indicates that simultaneous brain MRIs should be considered when performing MRI examinations for spinal cord diseases. However, this report describes a single case and lacks a histopathological evaluation for a definitive diagnosis of glioma, meningioma, or other types of brain tumors.