VSPN AOW : Acute onset of circling a... |
Acute onset of circling and dull mentation in a 1-year-old male neutered domestic shorthair cat.J Am Vet Med Assoc. June 2023;261(6):1 - 4.
Companion NotesCase report of Cuterebra larval migration to the CNS in a cat
Introduction on aberrant Cuterebra larval migration - Cuterebra larval infestation sporadically reported in the veterinary literature - most small mammal cases of cuterebriasis involve infestations of the skin and sc - during the summer (June through September) - when Cuterebra larvae migrate through host tissue - aberrant larval migration has been reported in the following: - pharynx - eye - thorax - cribriform plate - aberrant CNS Cuterebra larval migration - often result’s in acute, severe, and rapidly progressive neurological signs - typically affected cats are young to middle age and have access to the outdoors - clinical signs depend on the path of brain migration - resulting in a variety of clinical signs such as the following: - status epilepticus - blindness - head pressing - anorexia - circling - abnormal mentation - postural reaction deficits - abnormal gait - cranial nerve deficits - many affected cats also have a recent history of upper respiratory tract disease - probably from larval migration from nasal passage through the cribriform plate - before moving through brain parenchyma - rare prevalence - 6 reported cases in dogs - only 1 of the 6 survived the acute disease phase - > 20 cases in cats - prognosis is guarded to poor in most cases - presumptive diagnosis typically involves the following: - blood work commonly reveals the following: - peripheral leukocytosis with eosinophilia - consistent with parasitic or allergic disease - hyperglobulinemia - consistent with systemic inflammation - brain MRI - brain imaging often reveals a migrating Cuterebra larval track - and associated inflammation, edema, and hemorrhage - CSF analysis: eosinophilic pleocytosis - treatment suggested in most case reports of feline cerebral cuterebriasis - ivermectin at various dosages - 0.2 mg/kg sc once - 0.3 mg/kg sc q48h for 3 treatments - 0.3 mg/kg PO q14d for 2 treatments - 0.4 mg/kg sc q24h for 3 treatments - simultaneous use of 1 or more of the following also recommended (to prevent inflammatory or hypersensitivity reactions and infection) - anti-inflammatory corticosteroids - antihistamines - antibiotics
Case report of a 1-year-old, neutered, sex:M indoor-outdoor DSHcat - history, physical exam, tests and treatment at referring clinician (rDVM) - history of current vaccination - presentation 1 week prior for circling and dull mentation - treatment - clindamycin, 12.5 mg/kg PO q12h for possible toxoplasmosis - cat improved initially but declined 2 days before presentation - at referral for acute development of circling and dull mentation - neurological examination - ambulatory with left-sided hemiparesis - proprioceptive deficits, left side - blindness, left eye - absent left menace response - intact direct and consensual pupillary light reflexes oculus uterque (OU) - compulsive circling, to the right - altered mentation (dull) - physical examination - dehydration, 5% - pallor with pale mucous membranes - bradycardia - hypotension, moderate - blood pressure monitoring initiated - neurolocalization - depressed mentation can be due to the following: - forebrain or brainstem lesion - systemic disease - compulsive circling to the right could be due to the following: - forebrain lesion - vestibular dysfunction - lack of other vestibular signs made this unlikely - blindness oculus sinister and absent menace response on the left - with the following: - normal pupillary light reflexes - normal palpebral reflexes OU - dysfunction in right forebrain or left cerebellum most likely - left-sided proprioceptive deficits and hemiparesis can occur with the following: - right forebrain lesion considered most likely - considering the other deficits - left brainstem lesion - left cervical localization - likely location of the lesion: right forebrain - differential diagnoses for an acute, progressive right forebrain lesion (in a young indoor-outdoor cat) - infectious disease - FIP, bacterial, toxoplasmosis, or fungal meningoencephalitis - immune-mediated meningoencephalitis - parasitic disease (Cuterebra larval migration) - neoplasia (lymphoma) - congenital abnormalities (hydrocephalus, porencephaly) - toxins such as bromethalin - neurological signs of this typically have a multifocal localization - CBC and serum biochemistry: unremarkable - survey thoracic radiography: unremarkable - MRI of brain - L-shaped linear track within the brain parenchyma - extending from right frontal lobe immediately adjacent to cribriform plate: - cranially to the right caudate nucleus caudally - then turning left and continuing through the thalamus - into left temporal lobe - T2-weighted and FLAIR hyperintense and T1-weighted hypointense - moderately ring contrast enhancing with central hypointense region - focal region of contrast enhancement, within right caudal nasal cavity - CSF analysis (cerebellomedullary cistern) - elevated protein at 28 mg/dL with reference at < 25 - high normal nucleated cell count - 11% eosinophils, 2% medium mononuclear cells, 87% small lymphocytes - clinical diagnosis: verminous encephalopathy based on the following: (caused by aberrant Cuterebra larval migration) - mild inflammation and eosinophils identified on CSF cytology - MRI findings - treatment: IV fluids and maropitant - treatment following diagnosis of CNS Cuterebra larval migration - ivermectin, 0.4 mg/kg sc q24h for 3 days - treatment prior to each dose of ivermectin (to mitigate inflammatory reactions associated with parasite death) - dexamethasone sodium phosphate, 0.11 mg/kg IV q24h - diphenhydramine, 4 mg/kg IM q24h - ampicillin/sulbactam, 50 mg/kg IV q6h - enrofloxacin initiated but then stopped due to lack of clear indication - day 5, cat stable and IV medications were discontinued - cat transitioned to PO medications - day 6 cat discharged with PO medications - recheck 1 month after discharge - neurological examination - absent left-sided menace - intermittent inappropriate left foot placement when sitting - persistent but improved left-sided postural reaction delays - outcome by phone 24 months after diagnosis: cat doing well at home
“In summary, CNS cuterebriasis represents a neurologic disease more common in cats than dogs, resulting in presentation during summer months with acute onset and often asymmetric, focal or multifocal, intracranial signs preceded by upper respiratory disease…”
|
Article Tools:
Archives Highlights:
|
VSPN AOW : Acute onset of circling a... |
800.700.4636 | help@vspn.org | 530.756.4881 | Fax: 530.756.6035
777 West Covell Blvd, Davis, CA 95616 Copyright 1991-2024, Veterinary Information Network, Inc. |
Contact Us |