Magnetically elicited transcranial motor evoked potentials (MEPs) were studied in 37 dogs with type 1 intervertebral disc (IVD) disease. The waveforms were recorded from both cranial tibial muscles before and after surgery. The latencies and amplitudes obtained were compared to those of a control population (n = 14). MEPs were recordable in all dogs with mild or no neurologic deficits, but they were recordable in only 50% of ambulatory dogs that were severely ataxic. MEPs could not be elicited from nonambulatory dogs. There was a significant attenuation of the amplitudes in all clinical cases, even if the dogs demonstrated back pain alone. Significantly prolonged latencies were associated with neurologic deficits. MEPs were not good predictors of neurologic recovery. The responses obtained from the side where the disc material was found were not different from those recorded from the opposite side. MEPs were very sensitive to lesions of the spinal cord, as indicated by the significant changes in the waves in patients with mild or no neurologic deficits and in the loss of response in dogs that still demonstrated purposeful movement. Neurologic exams provided more accurate diagnoses and prognoses than did MEPs in dogs with IVD disease.

Transcranial magnetic MEP are useful to assess severity of cervical spinal cord disease in large-breed dogs. Impairment of the functional integrity of the cervical spinal cord was found even in dogs with neck pain alone.

Large defects of the hard palate can result from a congenital abnormality, trauma, or surgical treatment of oral masses. Closure of these defects can be challenging as dehiscence is common. Large, inoperable hard palate defects may be managed with prosthetic obturators, which recreate the separation between the oral and nasal cavities. This report describes the use of a palatal obturator to manage a large palatal defect that persisted after resection of a palatal fibrosarcoma. Three prior attempts at surgical closure of the defect had failed.

The sartorius muscle in the cat is a broad, sheet-like muscle which covers the craniomedial aspect of the thigh. The major portion of the blood supply arises from the proximal pole of the muscle. A single sartorius muscle can be positioned over the abdomen in a transverse manner along the pubis, to cover the entire (i.e., left and right sides) caudal 30% of the abdomen. It also can be extended in a cranial-to-caudal fashion where it covers approximately 80% of the length and 75% of the width of the ipsilateral abdomen. The sartorius muscle flap is easy to harvest and provides good coverage for defects of the caudal abdominal wall. This muscle flap was used successfully in two feline patients.

A lateral approach was used successfully in seven of 10 dogs to resolve fistulas which developed after total ear canal ablations and bulla osteotomies. The approach facilitated identification and removal of horizontal ear canal remnants in four of the 10 cases. Facial nerve function was worsened temporarily by lateral exploration in two cases. Seven cases had no fistula recurrence during follow-up, which ranged from 12 to 72 months. Three cases each had fistula recurrence one-to-two months after fistula exploration.

Magnetic motor evoked potentials (MMEPs) were recorded from the right cranial tibial muscle after magnetic stimulation of the left motor cortex in six dogs sedated with oxymorphone. Anesthesia was induced with an intravenous bolus of 5.5 mg/kg of methohexital and maintained with a methohexital infusion. The dogs inspired 100% oxygen during anesthesia. Blood pressure, heart rate, respiratory rate, esophageal temperature, and end-tidal carbon dioxide tension were recorded. The depth of anesthesia was increased until the amplitude of the MMEP was less than 5% of the control value, and the dogs were then allowed to recover. Every 5 minutes during anesthesia, a blood sample was taken for methohexital assay and at the same time, four replicate MMEPs were recorded. Plasma methohexital levels were significantly (P < 0.05) correlated with heart rate (p = 0.38) and end-tidal carbon dioxide tension (p = 0.49) and negatively correlated with respiratory rate (p = 0.74). There was no significant correlation between blood pressure and methohexital levels. The dogs regained consciousness at a plasma methohexital level of 10.4 +/- 3.8 micrograms/ml (mean +/- SD). The amplitude of the MMEP decreased significantly with increasing methohexital levels. In four dogs, the relationship was reasonably linear. The MMEP disappeared at a plasma methohexital level of 23 +/- 6.6 micrograms/ml. The latency of onset of the MMEP increased significantly from its control value of 14.7 +/- 1.0 ms to 17.5 +/- 1.3 ms at the highest methohexital levels at which MMEPs were recordable. This study demonstrated that MMEPs can be reliably recorded under methohexital anesthesia.

No abstract

No abstract