Diagnosis, treatment and postsurgical complications in a dog with epileptic seizures and a naso-ethmoidal meningoencephalocele

Neurosurgery in canine epilepsy

Epilepsy surgery is functional neurosurgery applied to drug-resistant epilepsy. Although epilepsy surgery has been established and achieves fair to good outcomes in human medicine, it is still an underdeveloped area in veterinary medicine. With the spread of advanced imaging and neurosurgical modalities, intracranial surgery has become commonplace in the veterinary field, and, therefore, it is natural that expectations for epilepsy surgery increase. This review summarizes current standards of intracranial epilepsy surgery in human medicine and describes its current status and expectation in veterinary medicine. Intracranial epilepsy surgery is classified generally into resection surgery, represented by cortical resection, lobectomy, and lesionectomy, and disconnection surgery, such as corpus callosotomy and multiple subpial transection. In dogs with drug-resistant epilepsy, corpus callosotomy is available as a disconnection surgery for generalized epilepsy. However, other types of disconnection and resection surgeries for focal epilepsy are limited to experimental studies in laboratory dogs and/or anecdotal case reports of lesionectomy, such as tumor or encephalocele removal, without epileptogenic evidence. Veterinary epilepsy surgery is a new and challenging neurosurgery field; with the development of presurgical evaluations such as advanced electroencephalography and neuroimaging, it may become more readily practiced.

Polysulfone tailor-made implant for the surgical correction of a frontoparietal meningoencephalocoele in a cat

Case summary

A 6-week-old entire female domestic shorthair cat was presented for evaluation of a soft bulge and a palpable skull defect on the forehead, present since adoption a few days earlier. The neurological examination revealed an absent menace response bilaterally and apparent blindness, localising the lesion to the occipital cortex. The main differential diagnoses were meningocoele (MC) and meningoencephalocoele (MEC). Surgical repair was proposed once the cat reached adult size. Meanwhile, the cat developed seizures and was treated with anticonvulsant therapy. At 6 months of age, CT confirmed a frontoparietal MEC with associated porencephaly. Based on a three-dimensional printed skull mould, a polysulfone implant was created. The meninges were dissected from the skin, a durectomy was performed and samples of the protruding brain were obtained. Part of the cerebrospinal fluid was drained until the size of the protruding brain decreased enough to be included below the implant that was anchored on top of the skull with cerclages. Histopathology confirmed the diagnosis of MEC. Three years and 7 months later, the cat had partially recovered vision but continued to seize monthly despite antiepileptic drugs.

Relevance and novel information

MC/MEC is a relatively uncommon disease reported in companion animals, and only four cases of surgical management have been described, and did not use a polysulfone tailor-made implant. In human medicine, surgical intervention is the treatment of choice. This case highlights a new implant option for surgical correction of MEC with good long-term result and no complications after 3 years and 7 months.

Case Report: Detection of Transferrin in a Dog Suspected of Having Cerebrospinal Fluid Rhinorrhea

A 12-year-old Yorkshire terrier was referred for epileptic seizures and nasal discharge. The fluid was clear and serous. Cerebrospinal fluid (CSF) rhinorrhea was suspected, based on clinical signs and MRI findings. In humans, analysis of nasal secretions to determine the concentration of glucose and brain-type transferrin has been widely used clinically in order to confirm the presence of CSF rhinorrhea. The glucose concentration in the nasal discharge was 74 mg/dL. Serum-type and brain-type isoforms of transferrin were detectable in the nasal sample. The concentration of glucose and brain-type transferrin could be useful for diagnosing CSF rhinorrhea.