Welcome to the latest edition of the BVNS Neurotransmitter.
Travis, a 3-year old MN Dalmatian, presented to BVNS Richmond in April of 2017. A month before coming to us, he was seen at his primary care veterinarian as well as an internist for vomiting, lethargy, and inappetence.
PRESENTING COMPLAINT
Ataxia and falling over when walking. Suspected spinal disease.
EXAM FINDINGS
Mentation: Subdued to dull
Posture of Head and Body: Limbs occasionally found in abnormal positions (ie. abducted, splayed, crossed)
Gait: tetraparesis with general proprioceptive ataxia noted in all 4 limbs. Occasionally, the patient displayed subtle signs of vestibular ataxia
Postural Reactions: Normal to slightly delayed paw replacement in the forelimbs and very delayed in both rear limbs
Thoracic Limb Reflexes: Normal withdrawal reflexes bilaterally
Pelvic Limb Reflexes: Normal patellar and withdrawal reflexes bilaterally
Cutaneous Trunci: Present bilaterally at L5 (normal)
Perineal Reflex: Normal
Muscle Tone: Normal tone
Cranial Nerve Function: Normal cranial nerve function
Retinal Exam: Normal fundic exam OU
Hyperesthesia: No pain elicited on spinal palpation or cervical manipulation
Other Findings: Patient resisted lateral recumbency and dorsal recumbency. After examination, the patient altered between dull and stupor in the exam room. Stumbling and not appropriately responsive to auditory or visual stimuli
Q/A
Based on Travis’ history and clinical signs, where would you localize?
Localization:
Multifocal localization. There were aspects of the exam that suggested intracranial disease (ie. alternating mental status, reduced response to auditory and visual stimuli), and other aspects that suggested spinal cord disease (tetraparesis).
What diagnostic plan should be considered?
Diagnostic Plan:
(i) Brain MRI: bilaterally symmetrical lesions within the brain most suggestive of metabolic, toxic, or degenerative disease. Given the historical hepatopathy, the lesions are consistent with Wilson disease. (see Figure 1 below)
(ii) Abbreviated Cervical MRI: normal←
(iii) Cerebrospinal Fluid Analysis: normal
Figure 1. MRI of Travis’ brain in April 2017
What is the tentative diagnosis for Travis’ case?
Tentative Diagnosis:
Brain disease consistent with neurotoxicity (endogenous>exogenous) or inborn error of cellular metabolism
DEFINITIVE DIAGNOSIS
What were the follow-up diagnostics?
Bile acid profile:
pre: 149.5 umol/L, (normal: 0 – 6.9 umol/L)
post: 280.6 umol/L, (normal: 0 – 14.9 umol/L)
Liver biopsy: descriptive for copper storage disease
Based on the results, what was the definitive diagnosis? What treatments should be initiated?
Definitive Diagnosis: Copper-storage disease with the secondary brain pathology consistent with Wilson disease in humans
Treatment: Penicillamine, Prednisone, Denosyl, and Phosphatidylcholine
FOLLOW-UP DIAGNOSTICS (ABOUT 7 MONTHS LATER):
Brain MRI: mild, bilaterally symmetrical lesions noted in the body of the thalamic hemispheres, the rostral thalamic nuclei, and the body of the caudate nuclei. The previously noted midbrain and lentiform lesions were no longer present. (see Figure 2 below)
Figure 2. MRI of Travis’ brain in November 2017
DISCUSSION
We are often presented with patients with signs consistent with “routine” spinal disease. Travis’ medical history prior to coming to BVNS was extremely important in explaining his clinical signs. His exam changed and took on different qualities during his initial consultation at BVNS. While he was sent to us for problems walking, it became clear that he had intracranial abnormalities as well. The brain MRI showed symmetrical abnormalities that are typical of toxic or metabolic derangements. Given his age, breed, lab work abnormalities, and some additional ancillary tests, an accurate diagnosis was reached. Copper-associated liver disease is common in Dalmatians and can also result in brain pathology.
TAKE HOME POINTS FROM DR. HIGGINBOTHAM
- A patient’s past medical history is extremely important.
- A patient’s condition can change abruptly during an exam.
- Bilaterally symmetrical brain disease is often associated with toxic or metabolic disease.
- Diseases such as Travis’ are treatable and potentially reversible.
Thank you to Cooke Veterinary Medical Center of Chesapeake, VA for referring this case.
Click HERE for a PDF version of this publication.
Selected References:
- Brewer G. Wilson disease and canine copper toxicosis. Am J Clin Nutr 1998; 67(suppl):1087S-1090S
- Webb CB, Twedt DC, Meyer DJ. Copper-associated liver disease in Dalmatians: a review of 10 dogs(1998-2001). J Vet Intern Med 2002; 16:665-668