Diagnostic yield and adverse effects of MRI-guided free-hand brain biopsies through a mini-burr hole in dogs with encephalitis.
BACKGROUND
The diagnosis of encephalitis is usually presumptive based on MRI, cerebrospinal fluid analysis, or both. A definitive diagnosis based on histopathology, however, is required for optimizing treatment strategies.


OBJECTIVE
To investigate the diagnostic yield and adverse effects of minimally invasive brain biopsies in dogs with encephalitis.


METHODS
Seventeen dogs with suspected encephalitis, based on MR imaging and cerebrospinal fluid analysis.


METHODS
Retrospective study. Minimally invasive, free-hand brain biopsy specimens were taken from forebrain lesions through a 4-mm burr hole using a Sedan side-cutting needle. Routine histopathological examination was performed. The adverse effects were assessed by MRI evaluations after biopsy procedure (12/17) and by sequential neurological examinations.


RESULTS
The overall diagnostic yield with regard to a specific type of encephalitis was 82%. Encephalitis was evident in an additional 12%, but a specific disease could not be determined. There were no deaths caused by the biopsy procedure itself, but the indirect case fatality rate was 6%. Morbidity was 29%, including stupor, seizures, tetraparesis, hemiparesis, ataxia, and loss of conscious proprioception. All these signs resolved within 3-14 days.


CONCLUSIONS
Minimally invasive brain biopsy in dogs with suspected encephalitis leads to a definite diagnosis in the majority of dogs, allowing for a specific treatment. The advantages of a definite diagnosis outweigh potential case fatality rate and temporary neurological deficits.
Department of Small Animal Medicine, University of Leipzig, Leipzig, Germany. flegel@kleintierklinik.uni-leipzig.de
T
T
Flegel
A
A
Oevermann
G
G
Oechtering
K
K
Matiasek
D000818:Animals; D001706:Biopsy / Q000379:methods / Q000662:veterinary*; D001921:Brain / Q000276:immunology / Q000473:pathology*; D004283:Dog Diseases / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D004285:Dogs; D004660:Encephalitis / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D008297:Male; D012189:Retrospective Studies