Case Study 4 (Page 1)

Patient History: A 4 year old, f/s, Dachshund was presented to the Veterinary Neurological Center with a 6-week history of episodic neck muscle spasms and pain. Her signs temporarily improved with administration of prednisone and analgesics (tramadol, methocarbamol, gabapentin).

NOTE: Other than subtle muscle spasms, this patient's neurological exam was normal. View the video below and watch for subtle cervical spasms.

Question: Based on the patient's history and the accompanying video, what are reasonable differential diagnoses for this patient?

Radiographs:

Question: What abnormalities are present in these radiographs? Click each image to enlarge.

Radiographs:

Question: Based on these radiographs and the presenting signs, can you diagnose the reason for this patient's pain?

Radiographs:

Question: Based on findings thus far, what is the next best step to find the problem?

Discussion: In general, an MRI is more diagnostic for evaluating neurological disease because of better soft tissue visualization. The majority of dachshunds with these clinical signs (neck pain and spasms) will have a Type I disk extrusion, which can be visualized on a CT scan. However, the lack of radiographic evidence for calcification calls for MRI, as a non-calcified disk probably would not have been visualized well on CT. (See CT vs. MRI). A myelogram may have been diagnostic, but is more invasive and shows less detail than MRI. Additionally, this patient's signs have been present for 6 weeks and conservative management in patients with cervical disk herniations is generally unrewarding. Cerebrospinal fluid analysis might be a consideration, but given this patient is a Dachshund, IVDD would still be more likely.

MR Images: (click to enlarge)

Sagittal T2	Axial T1 (no contrast)	Axial T1 (contrast)
Axial T1 (no contrast)	Axial T1 (contrast)

Question: Based on the previous findings and these MR images, what is most likely the cause of this patient's problem?

Discussion: There is a T2 hyperintensity of the entire cervical spinal cord. After contrast administration, there is contrast enhancement of the meninges of the entirety of the cervical spinal cord and caudal medulla oblongata, which should not be present. This is interpreted as meningoencephalomyelitis with secondary vasogenic edema throughout the cervical spinal cord and, to a lesser extent, the caudal brainstem. There is obstructive hydrocephalus at the level of the caudal medulla causing an enlarged fourth ventricle, presumed secondary to the meningomyelitits.

CSF Analysis:

A cerebrospinal fluid analysis was performed next because there was evidence of possible meningoencephalomyelitis.

LUMBAR CSF ANALYSIS RESULTS:

WBC Count: 4,500 to 5,000/cumm (Normal: <5)
RBC Count: Minimal (Normal: <5)
Protein: 1929.1 mg/dl (diluted 1:100). Normal lumbar CSF protein is less than 40 mg/dl.

CSF SLIDE IMAGES:

Question: Is this CSF analysis consistent with neoplasia or inflammation?