Case Study

Rads: Generalized Chondroid Intervertebral Disc Degeneration Post Hemilaminectomy in a 13 year old MN Dachshund dog

The patient presented to the ER service for progressive intermittent head tremors, lethargy and anorexia. Previous history of hemilaminectomy (right, T12-13) in June 2008; owners are pursing a second opinion as this may be a neurologic issue, especially since signs are progressively worsening. Recovery good from hemilaminectomy, although there has been some mild, residual HL weakness.

Owners report slowing down over the past four months -less play activity and needing to be carried up the stairs in the house. Hyporexia started one month ago. The patient showed more activity on a recent trip, although he did fall down the stairs about 14 days ago. Severe decline started about 1 week ago with anorexia and wt loss of 3.5# over the previous 3 weeks, severe lethargy. Head pressing noted over the past 24 hours and walking very close to walls. Owners describe him as being “out of it”.

Medications include Rimadyl (carprofen) 50mg PO q24 (started on 7/13), Denamarin q24, Thyroxine 0.2mg PO q12, Mirtazapine 7.5mg PO q24 (started 7/15), Tramadol 25mg PO q12 (started 7/17). No medications given on 7/18 prior to rads. No c/s/v/d.

Physical exam: bradycardia (60-70 bpm) and hypertension 220mmHg.

CBC: unremarkable. Chemistry: Azotemia (BUN 89, N = 7-27; Creat 3.2,N= 0.5-1.8); Phos 8.7, N = 2.5-6.8; Mildly increased calcium (12.1, N = 7.9 – 12.0); Mildly elevated lipase (1678, N = 500-1500), High normal electrolytes (Na 159, N = 144-160; K 5.8, n = 3.5-5.8; Cl 123, N = 109-122

DX

Chondroid intervertebral disc degeneration and multifocal disc herniation

Image Interpretation

Rads right lateral, left lateral and VD thorax: Osseous structures: There was a status after hemilaminectomy T12/13 with a severely collapsed intervertebral disc space, sclerosis and moderate new bone formation at the vertebral endplates. The new bone formation extended laterally and dorsally towards the vertebral canal. The intervertebral disc spaces T11/12 and L1/2 presented significant narrowing with endplate sclerosis and emerging spondylosis. Level with the intervertebral disc spaces T13/L1 and L2/3 there was moderate spondylosis with lateral and dorsal extension and endplate sclerosis. Moreover the area of the neuroforamen L2/3 appeared to be reduced. Multiple intervertebral discs revealed focal mineralization.

Extrathoracic/extra-abdominal soft tissue structures: Within normal limits.
Intrathoracic structures: The overall size of the cardiac silhouette was within normal limits. There
appeared to be mildly increased sternal contact on the lateral view which was mainly due to a
relatively round shape of the heart and the chest conformation, but the right ventricle presented
normal dimensions on the ventrodorsal view. The caudal vena cava was thin. The pulmonary vessels
were thin. No mediastinal enlargement was seen. The course of the trachea was normal. The
pulmonary parenchyma presented radiolucent, some minor incidental, age-related interstitial and
bronchial pattern was noted.
Intra-abdominal structures: The spleen was enlarged. The urinary bladder was in a relatively caudal
position but its caudal extent could not be fully assessed on these views. The stomach was contracted
on all 3 views.

Outcome

The radiographic findings are compatible with a status after hemilaminectomy T12/13, generalized
chondroid intervertebral disc degeneration and suggest multifocal disc herniation. The age (acute vs. chronic), character (ex- vs. protrusion) and myelocompressive effects (high volume vs. low
volume/high impact extrusion) and therefore the current relevance of these herniations cannot be
assessed radiographically.

Comments

CT, CT-myelogram or MRI to better evaluate the suspected lesions is recommended in presence of neurologic deficits.
Regarding the splenomegaly, an ultrasonographic examination of the abdomen to rule out infiltrative disease is indicated. Primary or reactive gastritis is a potential in this case as the stomach showed contraction persisting in all views obtained. This should be evaluated ultrasonographically also. The patient presented hypovolemia with underperfusion of the lung.