Page 1781 - Cote clinical veterinary advisor dogs and cats 4th

893.e2 Root Signature (Nerve)

Root Signature (Nerve)
VetBooks.ir

• Axillary or inguinal pain
BASIC INFORMATION
• Palpable axillary mass (uncommon) • Cerebrospinal fluid (CSF) analysis
• Biopsy: allows definitive diagnosis of con-
Definition • Paraparesis, hemiparesis, or tetraparesis if firmed mass lesions; benefit must be weighed
Non–weight-bearing lameness and pain involvement of the spinal cord against risk of procedure.
resulting from disturbances in sensation in a • Evidence of external trauma • Surgical exploration
nerve root or sensory nerve of the cervical or
lumbosacral intumescence is common with Etiology and Pathophysiology TREATMENT
nerve root compression in the cervical or lumbar • Potential causes:
intumescence. ○ Lateralized or foraminal intervertebral disc Treatment Overview
extrusion • Removal of the source of nerve root or spinal
Epidemiology ○ Neoplasia (peripheral nerve sheath tumors, nerve impingement
SPECIES, AGE, SEX lymphoma, primary neural tumors, • Provision of the optimal environment for
Depends on underlying cause; dogs, older adults metastatic) nerve recovery
(neoplasia); cats, young adults (lymphoma) ○ Trauma
○ Degenerative lumbosacral stenosis Acute General Treatment
GENETICS, BREED PREDISPOSITION ○ Discospondylitis Depends on underlying cause:
Dachshund, cocker spaniel, beagle, other • Clinical signs result from a sensory distur- • Surgical decompression for IVDD, degenera-
chondrodystrophoid breeds (intervertebral bance in the dorsal root or spinal nerve, tive lumbosacral stenosis
disc disease [IVDD]); German shepherds typically by compression. • Tumor resection with or without limb
(degenerative lumbosacral stenosis) • The spinal cord can be affected, causing amputation and laminectomy for peripheral
long tract signs (e.g., gait deficit distal to nerve sheath neoplasm; surgical intervention
RISK FACTORS the lesion). should be considered early in these cases
Multi-cat household (risk of feline leukemia • The dorsal longitudinal ligament of the (reduce extension of tumor/spinal cord
virus [FeLV]) vertebral column is thicker in the cervical involvement).
region, predisposing animals to lateral disc • Conservative therapy is generally ineffective
CONTAGION AND ZOONOSIS extrusions at this site. in relieving pain of cervical IVDD.
FeLV (cat-to-cat) Chronic Treatment
Clinical Presentation DIAGNOSIS • Attempt conservative therapy (protection of
DISEASE FORMS/SUBTYPES Diagnostic Overview the distal limb with a boot, physiotherapy)
• Acute (IVDD) Nerve root signature is a clinical diagnosis for traumatic brachial plexus injuries.
• Chronic, progressive (neoplasia) made by distinguishing lameness due to Amputation should be delayed for 6 months
• Intermittent (degenerative lumbosacral neurogenic pain from orthopedic lameness. if possible to allow for reinnervation.
stenosis) Paravertebral pain, muscle atrophy, and • Radiation therapy: nerve sheath tumors
neurologic deficits and a normal orthopedic • Lifelong exercise modification: IVDD
HISTORY, CHIEF COMPLAINT exam are all helpful in identifying nerve root • Physical rehabilitation: if trauma has com-
• Thoracic limbs > pelvic limbs signature. promised limb use
• Non–weight-bearing lameness and pain
• Paravertebral pain Differential Diagnosis Possible Complications
• Trauma • Orthopedic disorders • Persistent or progressive clinical signs
• Difficulty rising, reluctance to jump • Soft-tissue injury • Recurrence or acute progression of clinical
• Lack of response to nonsteroidal antiinflam- signs (IVDD)
matory medications Initial Database • Self-mutilation associated with dysesthesia
• Complete neurologic and orthopedic exams • Distal limb trauma associated with decreased
PHYSICAL EXAM FINDINGS • Vertebral radiographs: rule out orthopedic sensation and normal activity
• Non–weight-bearing lameness (limb typically causes, bony neoplasia, chronic discospon- • Surgical complications
held in flexion) dylitis; may support a diagnosis of IVDD,
• Often ipsilateral caudal cervical muscle degenerative lumbosacral stenosis, or nerve Recommended Monitoring
spasms with disc extrusions sheath neoplasm (enlarged intervertebral Follow-up exam and serial diagnostic
• Focal hyperesthesia (pain) typically follows foramen) studies as directed by the animal’s clinical
the dermatomal distribution of the affected • Many animals have orthopedic disease progression
nerve. A hallmark of nerve root signature is unrelated to the clinical signs.
pain. PROGNOSIS & OUTCOME
• Paresis and occasionally hypotonia of the Advanced or Confirmatory Testing
affected limb • MRI is far superior to all other imaging Depends on underlying cause:
• ± Neurogenic muscle atrophy if chronic (>1 modalities for ruling out nerve sheath • Good to excellent (according to clinical signs)
week) neoplasia and neuritis. for IVDD treated with decompression
• ± Ipsilateral Horner’s syndrome (T1-T3) • Myelography CT is useful for IVDD, • Fair to good (according to clinical signs) for
• ± Ipsilateral cutaneous trunci deficit (C8, degenerative lumbosacral stenosis, and nerve degenerative lumbosacral stenosis
T1) sheath neoplasm. • Guarded to fair for traumatic injury
• Paravertebral pain, resistance to cervical • Electromyography (EMG): changes are • Poor with nerve sheath neoplasia
manipulation present 1 week after denervation of muscle.

www.ExpertConsult.com