Imaging Diagnosis—magnetic Resonance Imaging of a Neuronal Heterotopia in the Brain of a Cat

Abstract

A domestic shorthair kitten was presented for evaluation and further treatment of seizures. Magnetic resonance imaging of the brain revealed a large multilobulated mass in the third ventricle extending into the right lateral ventricle with secondary obstructive hydrocephalus. The mass was homogeneously isointense to gray matter on T2W, T2-FLAIR, T2 W, T1W, and ADC images, and hyperintense on DW-EPI. There was no appreciable contrast enhancement. Seizures were managed medically and with subsequent ventriculoperitoneal shunt placement. Clinical status later deteriorated and the cat was euthanized. Histopathology confirmed that the mass was the result of neuronal heterotopia. To the authors' knowledge this is the first report of neuronal heterotopia in a cat.

Clinical and MRI findings of a suspected cortical malformation presented as a giant cerebral pseudomass in a German Shepherd dog

“…Seizures in cases with MCD have also been described in veterinary medicine as the malformation forms an epileptogenic lesion 19 . Clinical signs related to intracranial malformations in previous veterinary cases varied from seizures only to progressive neurological deficits 10,11 . A large surface area was affected in our dog, and it was hypothesized that the dog would respond poorly to medical management.…”

“…A classification scheme for MCD does not exist in veterinary medicine. There are several single case reports in veterinary medicine describing neuronal heterotopia including heterotopia in a miniature schnauzer, a sea lion, a cat and a chihuahua 9–12 . The three latter reports describe MRI findings compatible with gray matter heterotopia, which was confirmed with histopathology: two subcortical heterotopia and one periventricular heterotopia, respectively.…”

“…19 Clinical signs related to intracranial malformations in previous veterinary cases varied from seizures only to progressive neurological deficits. 10,11 A large surface area was affected in our dog, and it was hypothesized that the dog would respond poorly to medical management. However, despite the extent of the lesion, repeated interictal neurological examination was normal with no postural reactions or menace response deficits as seen on initial presentation.…”

“…Although rare, the most reported cortical malformations in dogs and cats include hydranencephaly/porencephaly, polymicrogyria, and lissencephaly 2–8 . New types of MCD have been recently added to the veterinary literature, but a classification scheme (as described in humans) has not yet been established 1,9–12 . Intractable epilepsy and cognitive delay are the main clinical signs in humans with MCD, particularly when the affected area is large 13 .…”

“…[2][3][4][5][6][7][8] New types of MCD have been recently added to the veterinary literature, but a classification scheme (as described in humans) has not yet been established. 1,[9][10][11][12] Intractable epilepsy and cognitive delay are the main clinical signs in humans with MCD, particularly when the affected area is large. 13 This case report describes the clinical and MRI findings, treatment and short-term outcome of a bizarre and dramatic suspected cortical malformation in a dog.…”